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Permit D19-0317 - THE CONFLUENCE APARTMENTS - STORMWATER VAULT AND TEMPORARY SHORING
THE CONFLUENCE APTS VAULT 3481 S 152ND ST FINALED 10/20/2021 D19-0317 Parcel No: Address: City °~f "wk^""^U Department of Community Development 630DSouthcen¢e,Boulevard, Suite #10D Tukwila, Washington 981Q8 Phone:2O6-431'367V Inspection Request Line: 206'438-9350 Web site: http://www.TukwilaWA.gov DEVELOPMENT PERMIT 0043000108 Permit Number: D19-0317 Project Name: THE CONFLUENCE APB'VAULT Issue Date: 12/23/2019 Permit Expires On: 6/20/2020 Owner/ Name: Contact Person: Name; l651BEUBVUEAVE, SEATTLE WA, 98122 JAKE DRAKE Address: Z5CENTRAL WAY STE4OO,K|R%LAND, VVA_98U33 Contractor: Name: R4Fm[0MPANY Address: 172I l32NDAVE NE, BELLEVUE'WA, 98DO5'ZZZ4 License No: RAFNC**061J7 Lender: Name: ENTERPRISE COMMUNITY LOAN FUND Address: 2025FIRST AVE, STEIZ5O,SEATTLE VVA,98I2l Phone: (425)260'7232 Phone: Expiration Date: 4/20/2020 DESCRIPTION DFWORK: CONSTRUCTION OF A STORMWATER VAULT AND TEMPORARY SHORING PUBLIC WORKS FEES TO8EPAID UNDER PUBLIC WORKS PERMIT NO, PW19-0120Project Valuation: $592,73510 Type cfFire Protection: Sprinklers: NO Fire Alarm: NO Type nfConstruction: Electrical Service Provided by: TUKWILA Fees Collected: $2,145.47 Occupancy per IBC: U Water District: 125 Sewer District: VALLEY VIEW Current Codes adopted bythe City of Tukwila: international Building Code Edition: international Residential Code Edition: International Mechanical Code Edition: Uniform Plumbing Code Edition: International Fuel Gas Code: National Electrical Code: VVACities Electrical Code: VVA[296~4GB: ate Energy Code: Public Works Activities: ^-~' Channp|izadon/Stipin8: Curb[ut/Accps$Sidewa|k: Fire Loop Hydrant: Flood Control Zone: HauUn8/OveoizeLoad: Land Altering: Volumes: Cut: D Fill: O Landscape Irrigation: Sanitary Side Sewer: Number O Sewer Main Extension: Storm Drainage: Street Use: Water Main Extension: Water Meter: No Permit Center Authorized Signature: Date: I hearby certify that I have read an o7ramined this permit and know the same to be true and correct. All provisions of law and ordinances governing this work will be complied with, whether specified herein or not. The granting cf this permit does not presume to give authority to violate or cancel the provisions of any other state or local laws regulating construction or the performance of work. I am authorized to sign and obtain this development permit and agree to eco sbions attached to this permit. Signature: PhntName: `EMWC � /7 9( <�� Date: ' / ' �/ "—^�\/ ` \ This permit shall become null and void if the work is not commenced within 180 days for the date of issuance, or if the work is suspended or abandoned for a period of 180 days from the last inspection. PERMIT CONDITIONS: l: 'BUILDING PERMIT [OND[OONS*** Z: Work shall be installed in accordance with the approved construction documents, and any changes made during construction that are not in accordance with the approved construction documents shall be resubmitted for approval. 3: All permits, inspection record card and approved construction documents shall be kept at the site ofwork and shall be open to inspection by the Building Inspector until final inspection approval is granted. 4: The special inspections and verifications for concrete construction shall be as required by IBC Chapter 17, Tab|e17011 S: The special inspections for steel elements ofbuildings and structures shall be required. All welding shall be done byaWashington Association nfBuilding Official Certified welder. 6: The special inspection of bolts to be installed in concrete prior to and during placement of concrete. 7: When special inspection is required, either the owner or the registered design professional in responsible charge, shall employ a special inspection agency and notify the Building Official of the appointment prior to the first building inspection. The special inspector shall furnish inspection reports tothe Building Official in ptimely manner. 8: A final report documenting required special inspections and correction of any discrepancies noted in the inspections shall besubmitted tothe Building Official. The final inspection report shall beprepared bythe approved special inspection: agency and shall be submitted to the Building Official prior to and as a condition offinal inspection approval. 9: SubOmdepreparation in drainage, excavation, compaction, and 0Prl4uirementsxhaUcnnhz,m strictly with the recommendations given inthe soils report. Special inspection |srequired, 10: All construction shall be done in conformance with the Washington State Building Code and the Washington State Energy Code. 11: Notify the City ofTukwila Building Division prior toplacing any concrete. This procedure isinaddition to any requirements for special inspection. 12: There shall be no occupancy of a building until final inspection has been completed and approved by Tukwila building inspector. No exception. 13: Remove all demolition rubble and loose miscellaneous material from lot or parcel of ground, properly cap the sanitary sewer connections, and properly fill or otherwise protect all basements, cellars, septic tanks, wells, and other excavations. Final inspection approval will be determined by the building inspector based onsatisfactory completion ofthis requirement. 14: All plumbing and gas piping work shall be inspected and approved under a separate permit issued by the City ofTukwila Building Department (ZU8'43l'367O). lS: All electrical work shall be inspected and approved under a separate permit issued by the City of Tukwila Permit Center, 16: Preparation before roncnetep|acement: Water shall beremoved from place ofdeposit before concrete is placed unless a tremie is to be used or unless otherwise permitted by the building official. All debris and ice shall beremoved from spaces tobeoccupied byconcrete. 17: VALIDITY OFPERMIT: The issuance or granting of a permit shall not be construed to be a permit for, or an approval of, any violation of any of the provisions of the building code or of any other ordinances of the City of Tukwila. Permits presuming tugive authority toviolate orcancel the provisions mfthe code orother ordinances of the City ofTukwila shall not bevalid. The issuance ofopermit based onconstruction documents and other data shall not prevent the Building Official from requiring the correction of errors in the construction documents and other data. 19: Utility and detention vaults, located infire apparatus access roads, shall bedesigned towithstand an outrigger load nf45'OOO|bs. 18: Contact The Tukwila Fire Prevention Bureau to witness all required inspections and tests. (City Ordinances #Z436and #Z437) 20: Any overlooked hazardous condition and/or violation of the adopted Fire or Building Codes does not imply approval ofsuch condition orviolation, 21: These plans were reviewed byInspector 51I. |fyou have any questions, please call Tukwila Fire Prevention Bureau at(206)575-44O7. 22: 'PUBLIC WORKS PERMIT COND|T|ON5*~* 23: Call to scheclu|e mandatory pre -construction meeting with the Public Works Inspector, (206) 438-9350, 24: The applicant or contractor must notify the Public Works Inspector at (206) 438-935.0 upon commencement and completion ofwork atleast Z4hours inadvance. All inspection requests for utility work must also be made 24hours inadvance. 25: Prior toconstruction, aUuti|hiesinthevidnityghaUbe0eld|nca\ed. NOTE: For Ot ufTukwi|aud|ity locates, call OIlorl'8OO-4Z4-5555. 26: Permit is valid between the weekday hours of 7:00 a.m. and 10:00 p.m. only. Coordinate with the Public Works Inspector for any work after S:OOpm.and weekends. 27: No work under this permit during weekend hours without prior approval by Public Works. Coordinate with the Public Works inspector. 28: Temporary erosion control measures shall beimplemented as the first order nfbusiness toprevent sedimentation off -site orinto existing drainage facilities. 29: The site shall have permanent erosion control measures in place as soon as possible after final grading has been completed and prior tothe Final Inspection. 30: Project shall comply with Geotechnical Engineering Report by PanGEO, Inc., dated August 7, 2017; and subsequent Geotechnica|Engineering Reports/Eva|uations. The Geotechnical Engineer of Record shall observe vault placement and prior to final permit sign -off shall certify in writing that the vault was installed per Geotechnical Engineer of Record recommendations. ]l: Vault vents shall have and grate at the top which would allow the a"IT-r4rcu|ationand prevent trash and debris toenter the vault. 32: Place confined space warning sign/plate (per OSHA Standards) within each accessopening. 33: All construction joints must be provided with water stops per the 2016 King County Surface Water Design Manual Section Sl3l 34: Detention Vault including access shall comply with Section 5.1.3 of the 2016 King CountySurface Water Design Manual Section PERMIT INSPECTIONS REQUIRED Permit Inspection Line: (2O6)438'9350 1700 8U|L0NGF|NAL" 0301 CONCRETE SLAB 5200 EROSION MEASURES 5210 EROSION MEASURES FNL 0201 FOOTING 0202 FOOTING DRAINS OZOO FOUNDATION WALL lGOO PUBLIC WORKS FINAL 5160 PUBLIC WORKS PRE -CON 4037 S|'[AST'|N-PLACE 4000 S|'CON[RETE[ONST 4046 S|'EPDXY/EXP[ONC 4034 S|'K8ETALPLATE [ONN 4028 S|'RE|NFSTEEL'VV[LD 4035 51'S0LS S090 STORM DRAINAGE 1 • CITY OF TUKWILA Community Development Department Public Works Department Permit Center 6300 Southcenter Blvd., Suite 100 Tukwila, WA 98188 hup://www.TukwitaWA.gov Building Permit No. Project No. Date Application Accepted: Date Application Expires: (For office u only) 'CONSTRUCTION PERMIT PERMIT APPLICATION Applications and plans must be complete in order to be accepted for plan review. Applications will not be accepted through the mail. **Please Print** SITE INFORMATION King Co Assessor's Tax No.: 0043000108 Site Address: 3481 S 152ND ST Tenant Name: R61itAe'4ltAi 716411a, (-1,1 P PROPERTY OWNER Name: BELLWETHER TUKWILA-L-6er-U_Lp Address: 1651 Bellevue Ave City: Seattle State: WA Zip: 98122 CONTACT PERSON — person receiving all project communication Name: Blueline - Jake Drake Address: 25 Central Way Suite 400 city: Kirkland State: WA zip' 98033 Phone: 425-250-7232 Email: jdrake@thebluelinegroup.com DESIGN PROFESSIONAL IN RESPONSIBLE CHARGE Name: Blueline - Chris Miller, PE Address: 25 Central Way Suite 400 City: Kirkland State: WA zip: 98033 Phone: 425-250-7249 Email: cmiller@thebluelinegroup.com GENERAL CONTRACTOR INFORMATION Company Name: RAFN Company Address: 1721 132nd Ave NE City: Bellevue State: WA Zip: 98005 Phone: 425-702-6600 St Contr Reg No.: RAFNC**061J7 Exp Date4/20/20 Tukwila Business License No.: 600275503 Suite Number: Floor: New Tenant: . Yes ..No ARCHITECT OF RECORD Company Name: Address: NOT City: State: Zip: Phone: APPLICABLE Email: ENGINEER OF RECORD Company Name: Site Structures - Dan Kosnik, SE Address: 10505 19TH AVE SE, Suite B City: Everett State: WA Zip: 98208 Phone: 425-357-9600 Email: dan@kosnik.com LENDER — WHO IS FUNDING THE PROJECT (required for projects $5,000 or greater per RCW 19.27.095) Name: b 06 uJekAn az- Wo us( v“) Address: ( ( ,. 5( E2).e\.e.viA.,e Ave City: State: IN 461 Zip; 9 8( za MONTHLY SERVICE BILLING -or- WATER METER REFUND/BILLING Name: Address: City: State: Zip: Phone: IV:Wet-mit Center (Rachelle)•Applications Word \ Cnnst metion Permit Application Revised 6-2019 duct,: Revised: June 2019 Page I of3 BUILDING DIVISION INFORMATION — 206-431-3670 Valuation of Project (contractor's bid price): $ 392,735 Existing Building Valuation: $ Describe the scope of work (please provide detailed information): Construction of a stormwater vault and temporary shoring. Will there be new rack storage? 11.. Yes 0.. No If yes. a separate permit and plan submittal will be required. Provide All Building Areas in Square Footage Below Existing Interior Remodel Addition to Existing Structure New Type of Construction per IBC Type of Occupancy per IBC l" Floor 2nd Floor 3' Floor Floors thru Basement Accessory Structure* Garage 0 Attached 0 Detached Carport 0 Attachcd 0 Detached Covered Deck Uncovered Deck PLANNING DIVISION INFORMATION — 206-431-3670 Single family building footprint (area of the foundation of all structures, plus any decks over 18 inches and overhangs greater than 18 inches) *For an Accessory dwelling, provide the following: Lot Area (sq ft): Floor area of principal dwelling: Floor area of accessory dwelling: *Provide documentation that shows that the principal owner lives in one of the dwellings as his or her primary residence. Number of Parking Stalls Provided: Standard: Will there be a change in use? El Ycs EI No Compact: Handicap: If "yes", explain. FIRE PROTECTION/HAZARDOUS MATERIALS — 206-575-4407 El Sprinklers U Automatic Fire Alarm EI None 0 Other (specify) Will there be storage or use of flammable, combustible or hazardous materials in the building? 0 .....,. Yes 0 No If "yes', attach list of materials- and storage locations on a separate 8-1/2" x 11" paper including quantities and Material Safety Data Sheets, PUBLIC WORKS INFORMATION — 206-433-0179 0 ...Permanent Water Meter Size (1) . " WO # (2) " WO # (3) " WO # El ..Temporary Water Meter Size (i). " WO # (2) " WO # (3) '' WO # 0 ... Water Only Meter Size '' WO # 0 ........Deduct Water Meter Size D ..Sewer Main Extension Public 0 Private E O...Water Main Extension Public 0 Private 0 NV Vaunt Center iRaclielleMpplications\ Word\ Consiruction Permit Application Revised 6-2019 docx Revised: June 2019 Page 2 of 3 PERMIT APPLICATION NOTES — Value of Construction -- In all cases, a value of construction amount should be entered by the applicant. This figure will be reviewed and is subject to possible revision by the Permit Center to comply with current fee schedules. Expiration of Plan Review — Applications for which no permit is issued within 180 days following the date of application shall expire by limitation. The Building Official may grant one or more extensions of time for additional periods not exceeding 90 days each. The extension shall be requested in writing and justifiable cause demonstrated. Section 105.3.2 International Building Code (current edition). I HEREBY CERTIFY THAT I HAVE READ AND EXAMINED THIS APPLICATION AND KNOW THE SAME TO BE TRUE UNDER PENALTY OF PERJURY BY THE LAWS OF THE STATE OF WASHINGTON, AND I AM AUTHORIZEDTO APPLY FOR THIS PERMIT. BUILDING OWNS OR AUTHORIZE AGENT: Signature: Print Name: Mailing Address: Day Telephone: Ci Date: (.7 q5-/.772 LoA 65 E, 10 hp W:Terrnit Center (Rachelle)1ApplicationsMord \Construction Permit Application Revised 6-2019 docx Revised: June 2019 Page 3 of 3 Bellwether Calculations Permit Number: D19.0317 Full Fee Per Unit (103) 60% Reduction 80% Reduction Total Reduction Fees Owing (override TRAKIT) Plan Check Fee $ 2,653.39 $ 25.76 $ 324.59 $ 1,607.49 $ 1,932.08 $ 721.31 Permit Fee $ 4,082.14 $ 39.63 $ 499.37 $ 2,473.06 $ 2,972.43 $ 1,109.71 Structural $ 928.69 $ 9.02 $ 113.61 $ 562.62 $ 676.23 $ 252.46 Technology Fee $ 204.11 $ 1.98 $ 24.97 $ 123,65 $ 148.62 $ 55.49 Wa State Surcharge $ 6.50 $ 6.50 $ 6.50 These should equal $ 7,874.83 $ 7,874.83 $ 5,729.37 $ 2,145.46 Total Due 0 0 Original fees without reductions. > TENANT IMPROVEIAENT VALUE 392735 EA 51.00 5392.73500 Or JOU Value, S392.786.00 0Add ai'Pay +.Relond ,Receipts 6 History QDeposks .2'invoking F$Un-Pay Description - Oty Amount Comments Paid Invoice "ill DEVELOPMENT 5973 77 09%30'19 ------ CHECK PLAN CHECK FEE 5721.31 R000.345.830.00.00 > Et STRUCTURAL CONSULTANT - - 0000.345.830.01.00 DEVELOPMENT RMIT FEE R000.322.100.00.00 PLAN CHECK FEE 6000.345830.0000 Et WASHINGTON STATE SURCHARGE 8640.237.114 > 'ES STRUCTURAL CONSULTANT - 8000.345830.0100 ES TECHNOLOGY FEE R000 322 000 04.00 5252.46 $6,686.95 SA 002.14 57 932.08 S6.50 5676.23 5204.11 Charged$7,874.83 41 Deposit Bel' 80.00 it Pald. 8978.77 Dar: • Updated fees with reductions. s+ ) I TENANT IMPROVEMENT VALUE 392735 EA 51.00 $392,735 00 13 Job Value: $392,735.00 u,4Kow1 Inlnrin41i1m CharglM $214547 Paid $9/,377 Due $1,1/1 /0 Add 4Psy *Refund uReceipts 14H1story ..,Deposits .x invoking L Un-Pay Desuipdon Oty Amount Comments Paid Invoice ' ` , 671 DEVELOPMENT �� '', 01 PLAN CHECK FEE R000.345.830.00.00 STRUCTURAL CONSULTANT R000.345,830.01.00 L. a, )'i Q DEVELOPMENT L..� I fa PERMIT FEE yR000.322.100.00.00 I M , I V PLAN CHECK FEE R000.345 830.00.00 E: WASHINGTON STATE ' d� SURCHARGE 0240 237.114 �,) $TRUCTURAL CONSULTANT R0 0,345.a30A1.00 (N El TECHNOLOGY FEE R000.322.900.04.00 $973.77 $727.31 $252.40 91,110.21 T140 12.04.... $1,109.71 $0.00 S6.50 S0.00 $55.49 TMC 12.04. _. 09,30/19 CHECK ri Charged: $2,145.47 4 Depos4 Bel: $0.00 d Paid: $973.77 Q Due: 61.17159. 10 Cash Register Receipt City of Tukwila Receipt Number R19282 DESCRIPTIONS ACCOUNT QU , NTITY , PAID PermitTRAK $1,171.70 D19-0317 Address: 34815 152ND ST Apn: 0043000108 $1,171.70 DEVELOPMENT $1,116.21 PERMIT FEE R000.322.100.00.00 0.00 $1,109.71 WASHINGTON STATE SURCHARGE B640.237.114 0.00 $6.50 TECHNOLOGY FEE $55.49 TECHNOLOGY FEE TOTAL. FEES PAID BY RECEIPT: R19282 R000.322.900.04.00 0.00 : • ‘ ,i, 1 $55.49 $10171.70 Date Paid: Thursday, December 12, 2019 Paid By: BELLWETHER HOUSING Pay Method: CHECK 21106 AINNOMMIWO. Printed: Thursday, December 12, 2019 4:17 PM 1 of 1 R SYSTEMS Cash Register Receipt City of Tukwila Receipt Number DESCRIPTIONS ACCOUNT QUANTITY PAID PermitTRAK $14,524.50 D19-0317 Address: 3481 S 152ND ST Apn: 0043000108 $973,77 DEVELOPMENT $973,77 PLAN CHECK FEE R000.345.830.00.00 0.00 $721.31 STRUCTURAL CONSULTANT R000.345.830,01.00 0.00 $252,46 D19-0318 Address: 3481 S 152N0 ST Apn: 0043000108 $13,550.73 DEVELOPMENT $13,550.73 PLAN CHECK FEE R000.345.830.00.00 0.00 $9,567.49 STRUCTURAL CONSULTANT R000.345.830.01.00 0.00 $3,983.24 TOTAL FEES PAID BY RECEIPT: R18710 $14,524.50 Date Paid: Monday, September 30, 2019 Paid By: BELLWETHER HOUSING Pay Method: CHECK 20313 Printed: Monday, September 30, 2019 3:10 PM 1 of 1 SYSTEMS Permit Number: D19-0317 Description: THE CONFLUENCE APTS - VAULT Applied: 9/30/2019 Approved: 12/6/2019 Site Address: 3481 S 1S2ND ST Issued: 12/23/2019 Finaled: 10/20/2021 City, State Zip Code:TUKWILA, WA 98188 Status: FINALED Parent Permit: Parent Project: Applicant: THE CONFLUENCE APTS - VAULT Owner: BELLWETHER TUKWILA LLCP Contractor: RAFN COMPANY Details: CONSTRUCTION OF A STORMWATER VAULT AND TEMPORARY SHORING PUBLIC WORKS FEES TO BE PAID UNDER PUBLIC WORKS PERMIT NO. PW19-0120. INSPEGTIONS SCHEDULED DATE COMPLETED DATE TYPE INSPECTOR RESULT REMARKS CONCRETE SLAB Bill Centen Notes: FOOTING Bill Centen Notes: FOUNDATION WALL Bill Centen Notes: SI-CAST-IN-PLACE Bill Centen Notes: SI-EPDXY EXP CONC Bill Centen Notes: SI-METAL PLATE CONN Bill Centen Notes: . SI-REINF STEEL - WELD Bill Centen Notes: SI-SOILS Bill Centen Notes: Printed: Wednesday, 08 December, 2021 1 of 3 Permi���@~���� Inspections t o x~�o "".~ ~ ...~��~~ ~~City of Tukwila SI-CONCRETE C0NST BixCemen Notes: pmsAUmM Ben Hayman Notes: TREE PROTECT MEASURE1� Max axnak,r ' ^ Notes: mm 4�7��O � 8'C�mCns E COwsr Lee Sipe PARTIAL4��0� AppnovAL Vault Oou,n�n��� Notes: p/A Approved: Vault reinforcing fin floor, contingent upon special inspection approval. 4/�AM�2uzo x 4/24/2020 5|'O]N[RET[ coNsT Lee!Sipe PARTIAL AppnOvxL reinforcing#ZVault waU, Notes: Vault walls mba,reinforcing per special inspection report 4o9a6s 5/13/2020 AMs/z]/znzo ' s|-COmcnsTc cowsT Lee Sipe pPARTIALe AppnowuL 4/475 Notes: Kw Vault lid reinforcing S.|report 3OZ7I7 5/14/2020 Am 5/14/2020 FOOTING DRAINS Lee Sipe 4ppRovEo Storm Vault footing drains only Notes: 10y14/2021 pPMzu/zo/zuzz PUBLIC WORKS FINAL Scott Moore Appnovso 2065104701 Notes: vktofinal Received and reviewed the storm vault video. 10/18 80/18/2021 AM / � 10/18/2021 | GV|Ln|mGF|N4L** | BiU[�men NOT APPROVED 2065104701 Notes; 1.Need toschedule Storm Drainage and Erosion measure inspections. lNeed Public Works Final approval. 3.Provide Final letter for all undParty Special inspections. 4.Need Fire Alarm/Fire Final, � �o/zy/zoaz EROSION xxsxsunsSpmL Eric Pritchard AppnoVso mv»e,: "pinspections ever called in Permit 0nsped~ons City of Tukwila 10/19/20I1 10/19/2021 EROSION msASVRc5 ScottMoore APPROVED Notes: 10 1n/lg/lVZ1 PUaucxVoRxSy�9/zn21 pnc'COm Scott Moore APPROVED Notes: noinspections ever called in 10y19/2021 10/19/2021 T STORM DRAINAGE Scott Moore APPROVED Notes: noinspections ever called in 10/20/2021 10/20/2021 BUILDING F|NAL*~ BiU[enten APPROVED } 2065104701 Printed: VVednesdav,UQDecember, 2021 3of3 GEOTECHNICAL REPORT PROPOSED APARTMENTS 3481 3703 South 152nd Street Tukwila, Washington REVIEWED FOR CODE COAPLIANCE 1 5 2019 City of "rukwile. BUILDING DIVISION L - L,ul ti 8 'L..,J scao‘a .0.0o Prepared for: Bellwether Housing PanGE INCORPOR ATED PROJECT NO. 17-211 August 2017 C\,'Y 30 2019 \fl:1 .:•- - • 0311 Geotecnnical & Earthquake Engineering Consultants SW PanGEED INCOR FOR STIP Geotechnical & Earthquake Engineering Consultants August 7, 2017 File No. 17-211 Mr. John Poulson Bellwether Housing 1651 Bellevue Avenue Seattle, Washington 98122 Subject: Geotechnical Report Proposed Apartments 3481 — 3703 South 152nd Street, Tukwila, Washington Dear Mr. Poulson: 1 • As requested, PanGEO,IInc. is pleased to present this geotechnical report for the proposed mixed -use apartment development at 3481 — 3703 South 152nd Street in Tukwila, Washington. In sumrnary, v enCOuritered about two to three feet of fill overlying medium dense to very dense glacial soils. In our opinion, the proposed structure may be supported using spread footings bearing on the dense glacial soils, or on structural fill placed above the dense glacial soils. We appreciate the opportunity to be of service. Should you have any questions, please do not hesitate to call. Sincerely, •••••••-, Scott D. Dinkelrnan, LEG -0' Senior Engineering Geologist 3213 Eastlake Avenue East. Suite B Seattle. WA 98102 F. (206) 262-0370 E. (206) 262-03'4 TABLE OF CONTENTS Section Page 1.0 GENERAL 1 2.0 SITE AND PROJECT DESCRIPTION 1 3.0 SUBSURFACE EXPLORATIONS 2 3.1 SITE GEOLOGY 2 3.2 EXPLORATION3 3.3 SOIL CONDITIONS .............3 3.4 GROUNDWATER 4 4.0 SENSITIVE AREAS CONSIDERATIONS 5 5.0 GEOTECHNICAL RECOMMENDATIONS 6 5.1 SEISMIC DESIGN PARAMETERS 6 5.2 BUILDING FOUNDATIONS ....,, 6 5.3 RETAINING AND BELOW -GRADE WALL DESIGN PARAMETERS 8 5.4 CONCRETE SLAB ON GRADE FLOORS 10 5.5 PERMANENT CUT AND FILL SLOPES 10 6.0 EARTHWORK CONSIDERATIONS 11 6.1 STRIPPING AND PROOFROLLING 11 6.2 TEMPORARY EXCAVATIONS 1 1 6.3 STRUCTURAL FILL PLACEMENT AND COMPACTION .12 6.4 MATERIAL REUSE 13 6.5 EROSION AND DRAINAGE CONSIDERATIONS 13 6.6 WET WEATHER CONSTRUCTION 13 7.0 ADDITIONAL SERVICES 14 8.0 CLOSURE 14 9.0 REFERENCES 17 ATTACHMENTS: Figure 1 Figure 2 Appendix A Figure A-1 Figure A-2 Figure A-3 Figure A-4 Figure A-5 Figure A-6 Vicinity Map Site and Exploration Plan Summary Test Boring Logs Terms and Symbols for Boring and Test Pit Logs Log of Test Boring PG-1 Log of Test Boring PG-2 Log of Test Boring PG-3 Log of Test Boring PG-4 Log of Test Boring PG-5 17-21 13703 S I52nd St - Geotech Report Page i PanGEO, Inc. GEOTECHNICAL REPORT PROPOSED APARTMENTS 3481-3703 SOUTH 152"D STREET TUKWILA, WASHINGTON 1.0 GENERAL As requested, PanGEO, Inc. is pleased to present this geotechnical report for the proposed mixed -use apartment development at 3481 — 3703 South 152nd Street in Tukwila, Washington. This study was performed in general accordance with our mutually agreed scope of services outlined in our proposal dated June 15, 2017. Our scope of services included reviewing readily available geologic maps and historical data, conducting a site reconnaissance drilling five test borings, and developing the conclusions and recommendations presented in this report. 2.0 SITE AND PROJECT DESCRIPTION The subject site is located at 3481 — 3703 South 152nd Street in Tukwila, Washington. The approximate location of the site is shown on Figure 1, Vicinity Map. The site is bordered to the west and south by asphalt paved parking lots, to the east by a three-story apartment building, and east by parking lots and mixed -use apartment, and to the north by South 52nd Street. The site consists of three rectangular shaped parcels that comprise a combined area of about 52,572 square feet. Plate 1, on the next page provides an aerial of the site. The site is currently occupied by four one-story single-family residences. There are large trees, shrubs, tall grass, and wooden and chain -link fencing around the properties. The overall site slopes down gently from north to south with about 10 feet of elevation change across the length of the site. We understand it is planned to remove the existing residences occupying the site to facilitate the construction of a new mixed -use apartment building. The proposed building will be seven stories in height and will consist of five levels of living space above a two- story parking garage. The building will be of concrete and wood -frame construction. The lower level of the parking garage will be benched into the site with a cut of about five feet deep alongthe west side of the site that daylights to the east. The upper level of parking will be about three feet above existing grade on the west side of the site. The excavation will be accomplished as an open cut with temporary side slopes. YEN MN Yr 011 NAM INN • r r • 7 6 # Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 Plate 1: Orthogonal aerial view of the subject site. South 152nd Street is located along the upper edge of photo. The conclusions and recommendations in this report are based on our understanding of the proposed development, which is in turn based on the project information provided. If the above project description is incorrect, or the project information changes, we should be consulted to review the recommendations contained in this study and make modifications, if needed. In any case, PanGEO should be retained to provide a review of the final design to confirm that our geotechnical recommendations have been correctly interpreted and adequately implemented in the construction documents. 3.0 SUBSURFACE EXPLORATIONS 3.1 SITE GEOLOGY Based our review of the Geologic Map of the Des Moines North 7.5' Quadrangle (Booth and Waldron, 2004) the primary surfice geologic units in the area of the site are Vashon Till (Geologic Map Unit Qvt) and Recessional Outwash (Qvr). Vashon Till (Qvt) is described by Booth and Waldron, as a compact diamict containing subrounded to well- rounded clasts in massive, silt- or sand -rich matrix. Glacially transported and deposited. Vashon Till typically exhibits low compressibility and high strength characteristics in its undisturbed state. 17-211 3703 S 152nd St - Geotech Report 2 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 1.52nd Street, Tukwila, Washington August 7, 2017 Recessional outwash consists of sand, gravel, cobbles, and minor amounts of silt deposited by meltwater streams emerging from the retreating glacier during the Vashon Stade of the Fraser Glaciation. This deposit has not been glacially overridden, as such it typically ranges from loose to dense. 3.2 EXPLORATION Five borings (PG-1 through PG-5) were drilled at the site on July 14, 2017. The borings were drilled using a Diedrich D-50 track -mounted drill rig owned and operated by Holocene Drilling Inc. of Puyallup, Washington. The approximate boring locations were identified in the field relative to on -site features. The approximate boring locations are shown on Figure 2. Borings PG-1 and PG-5 were drilled to a depth of about 161/2 feet, borings PG-2 and PG-3 were drilled to a depth of about 11 % feet, and PG-4 was drilled to a depth of about 101/2 feet below the existing grade, respectively. The drill rig was equipped with 6-inch outside diameter hollow stem augers. Soil samples were obtained from the borings at 21/2-foot depth intervals in general accordance with Standard Penetration Test (SPT) sampling methods (ASTM test method D-1586) in which the samples are obtained using a 2-inch outside diameter split -spoon sampler. The sampler was driven into the soil a distance of 18 inches using a 140-pound pneumatic hammer. The number of blows required for each 6-inch increment of sampler penetration was recorded. The number of blows required to achieve the last 12 inches of sample penetration is defined as the SPT N-value. The N-value provides an empirical measure of the relative density of cohesionless soil, or the relative consistency of fine-grained soils. A geologist from PanGEO was present to observe the drilling, assist in sampling, and to describe and document the soil samples obtained from the borings. The soil samples were described and field classified in general accordance with the symbols and terms outlined in Figure A-1, and the summary boring logs are included as Figures A-2 and A-6. 3.3 SOIL CONDITIONS The soils observed in the borings generally consisted of a thin layer of fill overlying Vashon till, which is consistent with the mapped geology. The following is a brief description of the soils encountered in the five borings advanced at the site. Please refer to the boring logs (Figures A-2 through A-6) for additional details. 17-211 3703 S 152nd Si - Geotech Report PanGEO, Inc. f 1 r /6. r -7 7 7 r r '7 r r -{ 7 •, Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 Topsoil — At our boring locations, we encountered a surficial layer of topsoil and sod. The topsoil layer ranged from six inches thick at Borings PG-2, PG-4 and PG- 5 to 12 inches thick at Borings PG-1 and PG-3. The topsoil consisted of silty sand and was characterized by its dark brown color and the presence of organics. Fill— At all five of our boring locations, we encountered a surficial layer of fill and disturbed soils. The fill extended to a depth of about two to three feet below the ground surface. The fill generally consisted of loose, silty sand and was characterized by its disturbed appearance and loose condition. Recessional Outwash — Below the fill at the locations of Borings PG-1 and PG-5, we encountered medium dense, gray -brown, sand to silt with scattered gravel. We classified this unit as recessional outwash. Weathered Vashon Till — Below the fill in Borings PG-2, PG-3 through PG-4 and below the recessional outwash in Borings PG-1 and PG-5, we encountered medium dense to dense, brown to gray, sand and sandy silt with scattered gravel. This unit appeared weathered and we interpreted this soil unit as weathered Vashon till. Vashon Till — The weathered till graded to unweathered at 3%2 to 12 feet below grade. The unweathered till consisted of medium dense to very dense, gray, silty sand with scattered gravel to the termination depths of all five borings. All five borings were terminated in dense to very dense Vashon till. Our subsurface descriptions are based on the conditions encountered and observed at the time of our exploration. Soil conditions between exploration locations may vary from those encountered. The nature and extent of variations between our exploratory locations may not become evident until construction. If variations do appear, PanGEO should be requested to reevaluate the recommendations in this report and to modify or verify them in writing prior to proceeding with earthwork and construction. 3.4 GROUNDWATER We did not encounter groundwater seepage in our borings at the time of our drilling. As such, we do not anticipate that groundwater seepage will result in construction related issues. 17-211 3703 S I52nd Si - Geotech Report 4 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152"d Street, Tukwila, Washington August 7, 2017 However, it should also be noted that groundwater elevations may vary depending on the season, local subsurface conditions, and other factors. Perched groundwater seepage may also develop during the wet season along the unweathered/weathered till contact. Groundwater levels are normally highest during the winter and early spring. 4.0 SENSITIVE AREAS CONSIDERATIONS As part of our study, we conducted a review of potential geotechnical sensitive areas within the subject site as defined in Tukwila Municipal Code (TMC) Title 18. Section 18.45.120 Areas of Potential Geologic Instability Designation, Rating and Buffers Identifies the following four classes of potential geologic instability: • Class 1 Areas: Where landslide potential is low, and which slope is less than 15% • Class 2Areas: Where landslide potential is moderate, which slope is between 15% and 40%, and which are underlain by relatively permeable soils • Class 3 Areas: Where landslide potential is high, which include areas sloping between 15% and 40%, and which are underlain by relatively impermeable soils or by bedrock, and which also include all areas sloping more steeply than 40% • Class 4 Areas: Where landslide potential is very high, which include sloping areas with mappable zones of groundwater seepage, and which also include existing mappable landslide deposits regardless of slope The approximate extent of the instability class areas are shown on the City of Tukwila's Sensitive Area Map http://www.tukwilawa.gov/wp-content/uploads/2015/11/Sensitive- Areas-Map.pdf. Based on our review of the Sensitive Area Map, there are localized areas on the east side of the site that are mapped as Class 2 Slope Areas, with slopes between 15 and 40 percent. Based on a reconnaissance of the site performed during our field exploration we did not identify any areas on -site with slopes between 15 and 40 percent. Based on our review and reconnaissance, in our opinion the site does not contain Class 2 or greater steep slope areas and consideration of steep slope hazards, setbacks, or buffers is not necessary for design. 17-211 3703 S I52nd St - Geotech Report PanGEO, Inc. • L. r • r 7 Geotechnical Report Proposed Apartments: 3481 — 3703 South 152"d Street, Tukwila, Washington August 7, 2017 5.0 GEOTECHNICAL RECOMMENDATIONS 5.1 SEISMIC DESIGN PARAMETERS The 2015 International Building Code (IBC) seismic design section provides a basis for seismic design of structures. Table 1, below provides seismic design parameters for the site that are in conformance with the 2015 IBC, which specifies a design earthquake having a 2% probability of occurrence in 50 years (return interval of 2,475 years), and the 2008 USGS seismic hazard maps. Table 1 — IBC Seismic Design Parameters Site Class Spectral Acceleration at 0.2 sec. (g) Ss Spectral Acceleration at 1.0 sec. (g) SI Site Coefficients Design Spectral Response Parameters Control Periods (sec.) Fa Fy SOS SDI To TS D 1.483 0.555 1.000 1.500 0.989 0.555 0.112 0.561 Liquefaction Potential — Liquefaction is a process that can occur when soils lose shear strength for short periods of time during a seismic event. Ground shaking of sufficient strength and duration results in the loss of grain -to -grain contact and an increase in pore water pressure, causing the soil to behave as a fluid. Soils with a potential for liquefaction are typically cohesionless, predominately silt and sand sized, must be loose, and be below the groundwater table. With the planned excavation to achieve construction subgrade elevations, the proposed building footprint will be predominantly underlain by medium dense to dense silty sand with gravel without an established groundwater table. Based on these conditions, in our opinion the liquefaction potential of the site is negligible and design considerations related to soil liquefaction are not necessary for this project. 5.2 BUILDING FOUNDATIONS It is our opinion that the proposed building may be supported on a spread footing foundation bearing on undisturbed medium dense to dense native soil or on structural fill placed on undisturbed native soils. Depending on the design footing subgrade elevation, 17-211 3703 S I52nd St - Gcotech Report 6 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152"d Street, Tukwila, Washington August 7, 2017 some over -excavation may be needed to remove the existing fill to expose the undisturbed native soils. Allowable Bearing Pressure — We recommend that an allowable soil bearing pressure of 4,000 psf be used to size the footings. For allowable stress design, the recommended allowable bearing pressure may be increased by one third for transient loading conditions such as wind and earthquake. Continuous and individual spread footings should have minimum widths of 18 and 24 inches, respectively. For frost protection considerations, exterior footings should be placed at least 18 inches below the final exterior grade. Interior spread foundations should be placed at least 12 inches below the top of concrete slabs. Footings designed and constructed in accordance with the above recommendations should experience total settlement of about one inch and differential settlement of about '/2 inch. Most of the anticipated settlement should occur during construction as dead loads are applied. Lateral Resistance — Lateral loads acting on footings may be resisted by passive earth pressure developed against the embedded portion of the footings and by frictional resistance developed at the base of the footings. For footings bearing on undisturbed native soils or on granular structural fill, a frictional coefficient of 0.35 may be used to evaluate sliding resistance. Passive soil resistance may be calculated using an equivalent fluid pressure of 350 pcf, assuming the footings are backfilled and the backfill is adequately compacted. The above values include a factor of safety of 1.5. Unless covered by pavements or slabs, the passive resistance in the upper 12 inches of soil should be neglected. Perimeter Footing Drain — Footing drains should be installed around the perimeter of the building, at or just below the invert of the footings. The footing drains should consist of minimum 4-inch diameter, perforated rigid PVC pipes (Schedule 35 minimum), embedded in pea gravel or clean crushed gravel placed at a rate of one cubic foot per lineal foot of pile, and wrapped with a nonwoven geotextile fabric, such as Mirafi 140N or equivalent. Footing drains should be graded to direct water to a suitable outlet. Under no circumstances should roof -downspout drain lines be connected to the footing drain system. Roof downspouts must be separately tightlined to an appropriate discharge. 17-211 3703 S 152nd St - Geotech Report 7 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 Cleanouts should be installed to allow for periodic maintenance of the footing drain and downspout tightline systems. Footing Excavation and Subgrade Protection — The footing subgrades should be carefully prepared. Any loose or softened soil should be removed from the footing excavations and replaced with structural fill. The prepared footing subgrade should be observed by PanGEO to confirm that the exposed footing subgrade is consistent with the expected conditions and adequate to support the proposed buildings. 5.3 RETAINING AND BELOW -GRADE WALL DESIGN PARAMETERS Retaining and below -grade building walls should be designed to resist the lateral earth pressures exerted by the soils behind the wall. Adequate drainage provisions should also be provided behind the walls to intercept and remove groundwater that may collect behind the walls. Wall Foundations — The recommendations outlined in section 5.2 Building Foundations of this report are applicable for retaining wall design and construction. Lateral Earth Pressures — Concrete cantilever walls should be designed for an equivalent fluid pressure of 35 pcf for level backfill behind the walls assuming the walls are free to rotate. If the walls are to be restrained at the top from free movement, such as basement walls, an equivalent fluid pressure of 45 pcf should be used for a level backfill condition behind the walls. Walls with a maximum 2H:1V backslope should be designed for an active and at rest earth pressure of 45 and 55 pcf, respectively. Permanent walls should be designed for an additional uniform lateral pressure of 8H psf for seismic loading, where H corresponds to the buried depth of the wall. The recommended lateral pressures assume that the backfill behind the wall consists of a free draining and properly compacted fill with adequate drainage provisions. For structures located below the basement floor slab (i.e., elevator pits or detention vaults) and it may not be feasible to install footing drains around the structure. In this case, the sidewalls should be designed for a lateral pressure of 90 pcf, including the effects of hydrostatic pressure. In addition, buoyancy below structures should also be included in the design considerations. 17-211 3703 S 152nd St - Geotech Report 8 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 Surcharge — Surcharge loads, where present, should be included in the design of retaining walls. We recommend that a lateral load coefficient of 0.35 be used to compute the lateral pressure on the wall face resulting from surcharge loads located within a horizontal distance of one-half the wall height. Lateral Resistance — Lateral forces from seismic loading and unbalanced lateral earth pressures may be resisted by a combination of passive earth pressures acting against the embedded portions of the foundations and by friction acting on the base of the foundations. Passive resistance values may be determined using an equivalent fluid weight of 350 pcf. This value includes a factor of safety of 1.5, assuming the footing is poured against dense native sand, re -compacted on -site sandy soil or structural fill adjacent to the sides of footing. A friction coefficient of 0.35 may be used to determine the frictional resistance at the base of the footings. The coefficient includes a factor safety of 1.5. Wall Drainage — Provisions for wall drainage should consist of a 4-inch diameter perforated drainpipe placed behind and at the base of the wall footings, embedded in 12 to 18 inches of clean crushed rock or drain rock wrapped with a layer of filter fabric. A minimum 18-inch wide zone of free draining granular soils (i.e. pea gravel or washed rock) is recommended to be placed adjacent to the wall for the full height of the wall. Alternatively, a composite drainage material, such as Miradrain 6000, may be used in lieu of the clean crushed rock or pea gravel. The drainpipe at the base of the wall should be graded to direct water to a suitable outlet. Wall Backfill — Retaining wall backfill should consist of free draining granular material. The site soils consist of silty sand with gravel and would not be suitable as wall backfill. We recommend importing a free draining granular material, such as Seattle Type 17 or a soil meeting the requirements of Gravel Borrow as defined in Section 9-03.14(1) of the W S DOT Standard Specifications for Road, Bridge, and Municipal Construction (WSDOT, 2016). In areas where space is limited between the wall and the face of excavation, pea gravel may be used as backfill without compaction. Wall backfill should be properly moisture conditioned to near its optimum moisture content, placed in loose, horizontal lifts less than 8 to 12 inches in thickness, and systematically compacted to a dense and relatively unyielding condition and to at least 95 percent of the maximum dry density, as determined using test method ASTM D-1557 (Modified Proctor). Within 5 feet of the wall, the backfill should be compacted with hand - operated equipment to at least 90 percent of the maximum dry density. 17-21 3703 S I52nd St - Geotech Report 9 PanGEO, Inc. r-- P r Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 5.4 CONCRETE SLAB ON GRADE FLOORS Slab on grade floors may be constructed using conventional concrete slab -on -grade floor construction. The floor slabs should be supported on competent native soil or on structural fill. Any overexcavation, if needed, should be backfilled with structural fill. Within areas of parking stalls and drive aisles, capillary break and vapor barriers are not necessary below the slab. If heated space or spaces that are sensitive to moisture intrusions are planned for the garage, concrete slab -on -grade floors should be underlain by a capillary break meeting the gradational requirements provided in Table 2, below. Table 2 — Capillary Break Gradation Sieve Size Percent Passing 3/4-inch 100 No. 4 0-10 No. 100 0 — 5 No. 200 0-3 The capillary break should be placed on subgrade soils that have been compacted to a dense and unyielding condition. * A 10-mil polyethylene vapor barrier should also be placed directly below the slab. Construction joints should be incorporated into the floor slab to control cracking. 5.5 PERMANENT CUT AND FILL SLOPES Permanent cut and fill slopes should be inclined no steeper than 2H:1 V. Cut slopes should be observed by PanGEO during excavation to verify that conditions are as anticipated. Permanently exposed slopes should be seeded with an appropriate species of vegetation to reduce erosion and improve stability of the surficial layer of soil. J 17-211 3703 S 152nd St - Geotech Report 10 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 6.0 EARTHWORK CONSIDERATIONS 6.1 STRIPPING AND PROOFROLLING Building, pavement and areas to receive structural fill should be stripped and cleared of surface vegetation, organic matter, and other deleterious material. Based on the thickness of the topsoil horizon encountered at our test pit locations, we anticipate a stripping depth of six to twelve inches across most of the site. The actual stripping depth should be based on field observations at the time of construction. Root balls from vines, brush, and trees should be grubbed to remove roots greater than about one -inch in diameter. The depth of grubbing to remove root balls could extend to l'/2 to 2 feet below the existing ground surface. Depending on the grubbing methods used, disturbance and loosening of the subgrade could occur during grubbing. Soil disturbed during the grubbing process should be compacted in -place to the requirements of structural fi 1 I. In no case should the stripped or grubbed materials be used as structural fill or mixed with material to be used as structural fill. The stripped materials may be "wasted" on site in non-structural landscaping areas or they should be exported. Following the stripping operation and excavations necessary to achieve construction subgrade elevations, the ground surface where structural fill, foundations, slabs, or pavements are to be placed should be observed by a representative of PanGEO. Proofrolling may be necessary to identify soft or unstable areas. Proofrolling should be performed under the observation of a representative of PanGEO. Soil in loose or soft areas, if re -compacted and still yielding, should be overexcavated and replaced with structural fill to a depth that will provide a stable base beneath the general structural fill. The optional use of a geotextile fabric placed directly on the overexcavated surface may also help to bridge unstable areas. 6.2 TEMPORARY EXCAVATIONS Based on our current understanding of the planned development, an excavation extending to a depth of up to five feet below grade is planned. Temporary excavations should be performed in accordance with Part N of WAC (Washington Administrative Code) 296-155. The contractor is responsible for maintaining safe excavation slopes and/or shoring. For planning purposes, the temporary excavations 17-211 3703 S 152nd St - Geotech Report 11 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152"d Street, Tukwila, Washington August 7, 2017 may be sloped as steep as 1 H: 1 V, but should be re-evaluated in the field during construction based on actual observed soil conditions. During wet weather, the cut slopes may need to be flattened to reduce potential erosion. The temporary excavations and cut slopes should be reviewed in the field during construction based on actual observed soil conditions. Depending on the timing of construction, the temporary slopes may need to be covered with plastic sheeting to protect them from erosion. Heavy construction equipment, building materials, excavated soil, and vehicular traffic should not be allowed within a distance equal to 1/3 the slope height from the top of any excavation. 6.3 STRUCTURAL FILL PLACEMENT AND COMPACTION Structural fill, should be free of organic and inorganic debris, be near the optimum moisture content and be capable of being compacted to the recommendations provided below. If the site soils cannot be compacted, then an imported structural fill may be needed. Fill for use during wet weather should consist of a well graded soil free of organic material with less than 5 percent fines (silt and clay sized particles passing the U.S. No. 200 sieve). Structural fill should be moisture conditioned to near their optimum moisture content, placed in loose, horizontal lifts less than 8 inches in thickness, and compacted to at least 95 percent maximum density, determined using ASTM D-1557 (Modified Proctor). The contractor should include costs for moisture conditioning the native soils by adding water as needed to achieve moisture conditions that will facilitate proper compact as a bearing subgrade or utility trench backfill. The procedure to achieve proper density of a compacted fill depends on the size and type of compaction equipment, the number of passes, thickness of the lifts being compacted, and certain soil properties. If the excavation to be backfilled is constricted and limits the use of heavy equipment, smaller equipment can be used, but the lift thickness will need to be reduced to achieve the required relative compaction. Generally, loosely compacted soils are a result of poor construction technique or improper moisture content. Soils with high fines contents are particularly susceptible to becoming too wet and coarse -grained materials easily become too dry, for proper compaction. Silty or clayey soils with a moisture content too high for adequate compaction should be aerated during dry weather, moisture conditioned by mixing with drier materials, or other methods. 17-211 3703 S 152nd St - Geotech Report 12 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 6.4 MATERIAL REUSE The soils underlying the site are moisture sensitive, and will become disturbed and soft when exposed to inclement weather conditions. We do not recommend using the site soils as structural fill. If it is planned to use the site soils in non-structural areas, the excavated soil should be stockpiled and protected with plastic sheeting to prevent it from becoming saturated by precipitation or runoff. 6.5 EROSION AND DRAINAGE CONSIDERATIONS We recommend that the exposed slopes be covered with plastic sheets. Surface runoff can be controlled during construction by careful grading practices. Typically, this includes the construction of shallow, upgrade perimeter ditches or low earthen berms in conjunction with silt fences to collect runoff and prevent water from entering excavations or to prevent runoff from the construction area leaving the immediate work site. Temporary erosion control may require the use of hay bales on the downhill side of the project to prevent water from leaving the site and potential storm water detention to trap sand and silt before the water is discharged to a suitable outlet. All collected water should be directed under control to a positive and permanent discharge system. 6.6 WET WEATHER CONSTRUCTION It is our opinion that construction of the project can be accomplished during wet season. However, performing earthwork activities during wet season is anticipated to be costlier than during dry weather conditions. General recommendations relative to earthwork performed in wet weather or in wet conditions are presented below: • All footing surface should be protected against inclement weather, unless the footings can be poured immediately after the subgrade is exposed. The contractor should be aware that the site soils are moisture sensitive due to its high fines content, and could become disturbed and soft when exposed to inclement weather conditions. It is the contractor's responsibility to protect the footing subgrade from disturbance. One option is to place 2 to 3 inches of lean - mix concrete or 4 to 6 inches of crushed surfacing base course on the footing subgrade as soon as the subgrade is exposed. 17-21 I 3703 S 152nd St - Geotech Report 13 PanGEO, Inc. • ( • J r r r - r Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 During wet weather, the allowable fines content of the structural till should be reduced to no more than 5 percent by weight based on the portion passing the 0.75-inch sieve. The fines should be non -plastic. The ground surface within the construction area should be graded to promote run-off of surface water and to prevent the ponding of water. Geotextile silt fences should be installed at strategic locations around the site to control erosion and the movement of soil. Excavation slopes and soils stockpiled on site should be covered with plastic sheeting. 7.0 ADDITIONAL SERVICES To confirm that our recommendations are properly incorporated into the design and construction, PanGEO should be retained to conduct a review of the final project plans and specifications, and provide construction monitoring of the foundation elements. The City, as part of the permitting process, may also require geotechnical construction inspection services. PanGEO can provide you a cost estimate for construction monitoring services on a later date. We anticipate that the following additional services will be required: • Review final project plans and specifications • Verify implementation of erosion control measures • Monitor the site excavations • Verify adequacy of footing subgrade • Verify the adequacy of subsurface drainage installation • Confirm the adequacy of the compaction of structural backfill • Other consultation as may be required during construction Modifications to our recommendations presented in this report may be necessary, based on the actual conditions encountered during construction. 8.0 CLOSURE We have prepared this report for Bellwether Housing and the project design team. Recommendations contained in this report are based on a site reconnaissance, a subsurface 17-211 3703 S 152nd St - Geotech Report 14 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 exploration program, review of pertinent subsurface information, and our understanding of the project. The study was performed using a mutually agreed -upon scope of services. Variations in soil conditions may exist between the locations of the explorations and the actual conditions underlying the site. The nature and extent of soil variations may not be evident until construction occurs. If any soil conditions are encountered at the site that are different from those described in this report, we should be notified immediately to review the applicability of our recommendations. Additionally, we should also be notified to review the applicability of our recommendations if there are any changes in the project scope. The scope of our work does not include services related to construction safety precautions. Our recommendations are not intended to direct the contractors' methods, techniques, sequences or procedures, except as specifically described in our report for consideration in design. Additionally, the scope of our services specifically excludes the assessment of environmental characteristics, particularly those involving hazardous substances. We are not mold consultants nor are our recommendations to be interpreted as being preventative of mold development. A mold specialist should be consulted for all mold -related issues. This report has been prepared for planning and design purposes for specific application to the proposed project in accordance with the generally accepted standards of local practice at the time this report was written. No warranty, express or implied, is made. This report may be used only by the client and for the purposes stated, within a reasonable time from its issuance. Land use, site conditions (both off and on -site), or other factors including advances in our understanding of applied science, may change over time and could materially affect our findings. Therefore, this report should not be relied upon after 24 months from its issuance. PanGEO should be notified if the project is delayed by more than 24 months from the date of this report so that we may review the applicability of our conclusions considering the time lapse. It is the client's responsibility to see that all parties to this project, including the designer, contractor, subcontractors, etc., are made aware of this report in its entirety. The use of information contained in this report for bidding purposes should be done at the contractor's option and risk. Any party other than the client who wishes to use this report shall notify PanGEO of such intended use and for permission to copy this report. Based on the intended use of the report, PanGEO may require that additional work be performed and that an 17-21 1 3703 S 152nd St - Geotech Report 15 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152nd Street, Tukwila, Washington August 7, 2017 updated report be reissued. Noncompliance with any of these requirements will release PanGEO from any liability resulting from the use this report. Sincerely, PanGEO, Inc. Scott D. Dinkelman, LEG Senior Engineering Geologist 17-211 3703 S 152nd St - Geotech Report Siew L. Tan, P.E. Principal Geotechnical Engineer 16 PanGEO, Inc. Geotechnical Report Proposed Apartments: 3481 — 3703 South 152"d Street, Tukwila, Washington August 7, 2017 9.0 REFERENCES International Code Council, 2015, International Building Code (IBC), 2012/2015. Booth, D.B., and Waldron, H.H., 2005, Geologic Map of the .Des Moines 7.5 ' Quadrangle, U.S. Geological Survey, U. S. Geological Survey Open file report 2004-2855, scale 1:24,000. WSDOT, 2016, Standard Specifications for Road, Bridge and Municipal Construction, M 41-10. 17-211 3703 S 152nd St - Geotech Report 17 PanGEO, Inc. la II l i it 11 II I I I ri all NM PM MI III r III / file.gtl ficlat 817117 (10 00) SDD W.0 CI -1I0 C W 0a 0 w dye ANC Try O. (t j z 0 J z z 0 z A 2 Al! Cargo Rd '.D 31 st PI S 32nd Ave S eS 34th Ave S 35th AveS 3701 Ave S v4Oth Ave S 0 5 5 V W N 0, 3 a v 51stAveS 53rdAve S SondPi" 54 3d PI S p1elP13‘ uam4lnos 1111411111111111 N M J w v 5 i w Q1 VI7 N 4 y N r► 42nd Ave S 9 44th Ave S 546thAve S 47thAve S n 6,6 47thAveS ti 48th Ave S 515t Ave S J VI VIJ CO T30th Ave S 0, 30thAve S 2ndAve S luk►vi,. 1100 cn 46th Ave S SId— G 4 51stAve S 51stAve S 16thAve S 0) P 5 34th Ave S 13Ivf 0, 28th Ave S 29th Ave 31stAveS CO2ptel,e4s0 3 � Ln SBAVI 3 a .i r+ A 42nd Ave S in ~ " 43rdAveS (1) 44 J 55 M M 53rdAve S r�ePe-�ew 55th Ave S t 6Q N 0 56th Ave S 0 N y 57th Ave S y �' v 3 et ' t le.grf w/ file. dal 8/7/17 (10.03) ASH ICI Not to Scale I+ :PG w 1 (2') low 1.r r k s awr i ti PG-1 11111111.10 w r i PG-3 (2-1/2') i 1 1 PG-2 t (2') Subject Site woo rwar a art aaa meow re gm aid r ar MO w 411.111.111 aa► i a.JI LEGEND: Approximate Boring Location, PanGEO, Inc., July 2017 (Approximate Fill Thickness in Feet) PanGE® INCORPOR AT ED Proposed Apartments 3481 - 3703 S 152nd St Tukwila, WA BORING LOCATIONS Projea :c 17-211 Figure No. 2 APPENDIX A SUMMARY TEST BORING LOGS 00 RELATIVE DENSITY / CONSISTENCY SAND/ GRAVEL SILT/CLAY Density SPT N•values Approx. Relative Density (%) Consistency SPT N-values Approx. Undrained Shear Strength (psf) Very Loose Loose Med, Dense Dense Very Dense <4 4 to 10 10 to 30 30 to 50 >50 <15 15 • 35 35 • 65 65- 85 85 - 100 Very Soft Soft Med. Stiff Stiff Very Stiff Hard <2 2 to 4 4 to 8 8 to 15 15 to 30 >30 <250 250 - 500 500 • 1000 1000 • 2000 2000 - 4000 >4000 UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP DESCRIPTIONS Gravel 50% or more of the coarse fraction retained on the #4 sieve. Use dual symbols (eg. GP -GM) for 5% to 12% fines. GRAVEL (<5% fines) GRAVEL (>12% fines) Sand 50% or more of the coarse fraction passing the #4 sieve. Use dual symbols (eg. SP-SM) for 5% to 12% fines. SAND (<5% fines) SAND (>12% fines) Silt and Clay 50%or more passing #200 sieve Liquid Limit <50 Liquid Limit > 50 Highly Organic Soils 1.1 111, GW Well -graded GRAVEL GP Poorly -graded GRAVEL GM Silty GRAVEL GC Clayey GRAVEL SW Well -graded SAND SP Poorly -graded SAND SM Silty SAND SC Clayey SAND MI SILT CL Lean CLAY OL MH Organic SILT or CLAY Elastic SILT CH OH PT Fat CLAY ......... ..... „ .. ...... ..... ......... Organic SILT or CLAY PEAT Notes: 1. Soil exploration logs contain material descriptions based on visual observation and field tests using a system modified from the Uniform Soil Classification System (USCS). Where necessary laboratory tests have been conducted (as rioted in the "Other Tests" column), unit descnptions may include a classification. Please refer to the discussions in the report text for a more complete description of the subsurface conditions. 2. The graphic symbols given above are not inclusive of all symbols that may appear on the borehole logs. Other symbols may be used where field observations indicated mixed soil constituents or dual constituent materials. DESCRIPTIONS OF SOIL STRUCTURES Layered: Units of material distinguished by color and/or composition from material units above and below Larninated: Layers of soil typically 0.05 to 1 mm thick, max. 1 cm Lens: Layer of sail that pinches out laterally Intedayered: Alternating layers of difering soil material Pocket: Erratic, discontinuous deposit of limited extent Homogeneous: Soil with uniform color and composition throughout Fissured: Breaks along defined planes Slickensided: Fracture planes that are polished or glossy Blocky: Angular soil lumps that resist breakdown Disrupted: Soil that is broken and mixed Scattered: Less than one per foot Numerous: More than one per foot BCN: Angle between bedding plane and a plane normal to core axis COMPONENT DEFINITIONS COMPONENT SIZE I SIEVE RANGE COMPONENT SIZE / SIEVE RANGE Boulder. Cobbles: Gravel Coarse Gravel: Fine Gravel: > 12 inches 3 to 12 inches 3 to 3/4 inches 3/4 inches to #4 sieve Sand Coarse Sand: Medium Sand: Fine Sand: Silt Clay #4 to #10 sieve (4.5 to 2,0 mm) #10 to #40 sieve (2.0 to 0.42 mm) #40 to #200 sieve (0.42 to 0.074 mm) 0.074 to 0.002 mm <0.002 mm TEST SYMBOLS for In Situ and Laboratory Tests listed in "Other Tests" column. ATT Comp Con DO DS %F GS Perrn PP R SG TV TXC UCC Atterberg Limit Test Compaction Tests Consolidation Dry Density Direct Shear Fines Content Grain Size Permeability Pocket Penetrometer R-value Specific Gravity Torvane Triaxial Compression Unconfined Compression SYMBOLS Samplelln Situ test types and intervals il 2-inch OD Split Spoon, SPT (140-1b. hammer, 30" drop) 3.25-inch OD Spilt Spoon (300-lb hammer, 30" drop) Non-standard penetration test (see boring log for details) Thin wall (Shelby) tube Grab Rock core Vane Shear MONITORING WELL sz Groundwater Level at time of drilling (ATD) Static Groundwater Level Cement / Concrete Seal Bentonite grout 1 seal Silica sand backfill Slotted tip Slough Bottom of Boring MOISTURE CONTENT Dry Moist Wet Dusty, dry to the touch Damp but no visible water Visible free water PanGE® INCORPOR ATED Phone: 206.262.0370 Terms and Symbols for Boring and Test Pit Logs Figure A-1 Project: 3481- Job Number: 17-2137031 South 152nd Street Location: NorNorthithi 3481-3703 South 152nd Street Coordinates: ng: 47.466197, Easting:-122.28647 Surface Elevation: 327.OR Top of Casing Elev.: Drilling Method: Hollow Stem Auger Sampling Method: SPT N o Depth, (ft) o Z °� c CO Other Tests Symbol N-Value • PL Moisture LL o m to . ay © MATERIAL DESCRIPTION p RQD Recovery 50 100 - Very loose, damp, dark brown silty sand with organics (TOPSOIL]. . . . . . . . ►,:* • *•♦ • Loose, moist, brown, silty SAND [FILL]. : : . . • 4 • •* S-1 11 19 Dense, moist, gray, SAND with grave t and trace sift [RECESSIONAL OUTWASH]. /// 3 12 Dense, moist, brown, SILT with gravel and trace sand [RECESSIONAL OUTWASH]. , ,.2 AA 23 % ,/ /7 V i, 6 - Becomes medium dense. Increase in sand content. % %A 8 S3 8"6 %• ,9 � 10 S4 9 18%/- 18 - Becomes dense. %//�. / /A/ • 12 - - .` Very dense, moist, brown, silty SAND with trace gravel [VASHON TILL]. - Drilling becomes harder at 12 feet below grade. -14 S' 27 .: / 16 43 J /l Boring terminated at 16.5 feet. Groundwater was not encountered during drilling. 18- - 20 Completion Depth: 16.5ft Date Borehole Started: 7/14/17 Date Borehole Completed: 7/14/17 Logged By: Alex Hess Drilling Company: Holocene Drilling Remarks: Surface elevation estimated based review of King County iMap website. Boring drilled using a Diedrich D-50 limited access track mounted drill rig. Standard Penetration Test (SPT) sampler driven with a 140 pound pneumatic hammer. IRICORPOR PanGE® LOG OF TEST BORING PG-1 A TEO Figure A-2 The stratification lines represent approximate boundaries. The tran on may be gradual. Sheet 1 of 1 Project: 3481-3703 South 152nd Street Job Number: 17-211 Location: 3481-3703 South 152nd Street Coordinates: Northing: 47.466152, Easting: -122.2861 Surface Elevation: 327,0ft Top of Casing Elev.: Drilling Method: Hollow Stem Auger Sampling Method: SPT o Z a) 94 in in' N 0 • PL Moisture LL 1 is • 0 E al cn 1I-E E iti com `� cu >' MATERIAL DESCRIPTION M 0 RQD Recovery 50 100 - .'{'r'''-- Loose, damp, dark brown silty SAND with organics [TOPSOIL]. I- 2 •• SilL Z a;• • m• Loose, moist, brown, silty SAND {FILL]. Dense, moist, brown, SAND with silt and trace gravel [WEATHERED . • • • • . . " . . • • _ 4 7 2© VASHON TILL]. ffy - - Medium dense, moist, gray, silty SAND with trace gravel [VASHON TILL]. ^ _ S-2 10 - Drilling becomes harder at 4 feet. 7r 6 11 11 - Becomes dense. �'� /�r 8 _ S 3 16 10 - _ S-4 18 28 43 - Becomes very dense. %%,� ice/ ////// Boring terminated at 11.5 feet below grade. Groundwater was not 12 encountered during drilling. . P-14- - 16 ......... ......... -18 `20 ......... ......... Completion Depth: 11.5ft Date Borehole Started: 7/14/17 Date Borehole Completed: 7/14/17 Logged By: Alex Hess Drilling Company: Hollocene Drilling Remarks: Surface elevation estimated based review of King County iMap website. Boring drilled using a Diedrich D-50 limited access track mounted drill rig. Standard Penetration Test (SPT) sampler driven with a 140 pound pneumatic hammer. BanGE® LOG OF TEST BORING PG-2 INCORPORATED Figure A-3 The stra on lines represen ppro ate boundaries. The nsition may be gradual. Sheet 0 Project: 3481-3703 South 152nd Street Job Number: 17-211 Location: 3481-3703 South 152nd Street Coordinates: Northing: 47.46644, Easting: -122.286311 Surface Elevation: 331.01 Top of Casing Elev.: Drilling Method: Hollow Stem Auger Sampling Method: SPT 0 Other Tests MATERIAL DESCRIPTION N-Value • PL Moisture LL • RQD Recovery 50 100 S- 0- 2- 4 18 20 2 3 6 8 4 7 9 4 8 15 32 24 35 y Loose, dark brown, silty SAND with organics [TOPSOI Loose, moist, brown, silty SAND [FILL]. Medium dense, moist, brown, sandy SILT with trace gravel [WEATHERED VASHON TILL]. Medium dense, moist, gray, silty SAND with trace gravel [VASHON TILL]. - Drilling becomes harder at 7 feet. — Becomes very dense. Boring terminated at 11.5 feet below grade. Groundwater was not encountered during drilling. Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Company: 11.5ft 7/14/17 7/14/17 Alex Hess Holocene Drilling Remarks: Surface elevation estimated based review of King County iMap website. Boring drilled using a Diedrich D-50 limited access track mounted drill rig. Standard Penetration Test (SPT) sampler driven with a 140 pound pneumatic hammer. PanGE® OR POR A T E D LOG OF TEST BORING PG-3 Figure A-4 The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1 of 1 Project: 3481-3703 South 152nd Street Job Number: 17-211 Location: 3481-3703 South 152nd Street Coordinates: Northing: 47.466853, Easting: -122.286061 Surface Elevation: 332.0ft Top of Casing Elev.: Drilling Method: Hollow Stem Auger Sampling Method: SPT 0 2 4 6 ci z a) E a) c. E V) co aTo 0 -6 E MATERIAL DESCRIPTION N-Value A PL Moisture LL • RQD Recovery P. 0 50 100 - 8 - - 10 - - 12 - - 14 - - 16 - - 18 - S-1 S-2 S-3 S-4 z 4 8 7 12 13 16 12 14 19 50/6 20 Completion Depth: Date Borehole Started: Date Borehole Completed: Logged By: Drilling Com pany: Loose, damp, dark brown silty SAND with organics [TOPSOIL]. Loose, moist, brown, silty SAND [FILL]. Medium dense, moist, brown, sandy SILT with trace gravel [WEATHERED VASHON TILL]. Medium dense, moist, gray, silty SAND with trace gravel [VASHON TILL]. - Drilling becomes harder at 3.5 feet. - Becomes dense. - Becomes very dense. Boring terminated at 10.5 feet. Groundwater was not encountered during drilling. ............... ......... ......... ....... V./1,4F vfl, : ......... ........ ......... 11.5ft 7/14/17 7/14/17 Alex Hess Holocene Drilling Remarks: Surface elevation estimated based review of King County iMap website. Boring drilled using a Diedrich 0-50 limited access track mounted drill rig. Standard Penetration Test (SPT) sampler driven with a 140 pound pneumatic hammer. PanGE® IIIICOR POR ATED LOG OF TEST BORING PG-4 Figure A-5 The stratification lines represent approximate boundaries. The transition may be gradual. Sheet 1 of 1 r r- Project: 3481-3703 South 152nd Street Job Number: 17-211 Location: 3481-3703 South 152nd Street Coordinates. Northing: 47.46667, Easting: -122.28657 Surface Elevation: 332.ofl Top of Casing Elev.: Drilling Method: Hollow Stem Auger Sampling Method: SPT .0. 1.) 0 Depth, (ft) 11111. !III!. Sample No. Sample Type Other Tests Symbol N-Va ue • PL Moisture LL 03 MATERIAL DESCRIPTION 1 • I RQD 50 Recovery 00 .S Loose, damp, silly SAND with organics TOPSO L . .• • ••• • • to • • • • 4••• • • • • Loose, moist, brown, silty SAND [FILL]. ......... ......... Medium dense, moist, gray -brown, poorly graded SAND with grave M11111111111111111111111111111 S-1 6 9 10 • and trace silt [RECESSIONAL OUTWASH]. pilfirpyr/ (XI a **/.. /d• ,#. -2 to 1 2 7 V V i • • t f I IIII 3 - Increase in silt content. - 9 0 1? rir/r1 A A 0 1 W., // 111111111111111 * 5Medium 7 1 2 dense, moist, gray -brown, SILT with sand and trace gravel [VVEATHERED VASHON TILL]. r/Orrif377j7111/7/1 el i riA el, 2 - - 14 - Dense, moist, gray -brown, sitty AND with trace gravel [VASHON S-5 1 2 1 4 TILL]. Drilling became harder at 14.5 feet, 44 4 16 2 5 , V • Boring terminated at 16.5 feet below grade. Groundwater was not encountered during drilling. - 18 - 20 Completion Depth: 16.5ft Date Borehole Started: 7/14/17 Date Borehole Completed: 7/14/17 Logged By: Alex Hess Drilling Company: Holocene Drilling Remarks: Surface elevation estimated based review of King County iMap website. Boring drilled using a Diedrich D-50 limited access track mounted drill rig. Standard Penetration Test (SPT) sampler driven with a 140 pound pneumatic hammer. PanGE® NCORPOR LOG OF TEST BORING PG-5 ATE') Figure A-6 The stratification lines represent approximate boundaries. The t nsiti n ay be gradual. Sheet 1 of 1 GENERAL INSTRUCTIONS AND CAVEATS Mt 0 8 2019 n.oc6.01t-to‘ '.' Di)! T2-1-ON! This template presents the recommended structure and content for preparation of a Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP). The Washington State Department of Ecology's (Ecology) CSWGP requirements inform the structure and content of this SWPPP template; however, you must customize this template to reflect the conditions of your site. A Construction Stormwater Site Inspection Form can be found on Ecology's website. http://www.ecv.wa.qov/programs/wo/stormwater/construction/index.html Using the SWPPP Template Each section will include instructions and space for information specific to your project. Please read the instructions for each section and provide the necessary information when prompted. This Word template can be modified electronically. You m add/delete text, copy and paste, edit tables, etc. Some sections may be co brief answers while others may require several pages of explanation. INSTRUCTIONS Instructions are identified by gray shading, and should be deleted upon S completion. Delete this entire section upon SWPPP completion. Use the F11 key for easier navigation through the form fields. pleREVIEINED FOR CODE COMPLIANCE APPROVED NOV 1 5 2019 PPP City of Tukwila BUILDING DIVISION After completing your template, and removing the gray instruction boxes, right -click anywhere on the Table of Contents and choose "Update Field", then choose "Update page numbers only", click "OK". Do the same for the list of Tables. Follow this link to a copy of the Construction Stormwater General Permit: http://www.ecy.wa.00v/oroorams/wo/stormwater/construction/index.html RECEIVECCD VW oTCJIMLit SFP 3 0 2019 PERMIT CENTER b I o n Construction Stormwater General Permit (CSWGP) Stormwater Pollution Prevention Plan (SWPPP) for Bellwether Affordable Apartments Prepared for: Department of Ecology Northwest Regional Office Permittee / Owner Developer Operator / Contractor Bellwether Tukwila LLLP Bellwether Tukwila LLLP RAFN Company 3481 S 152nd St Certified Erosion and Sediment Control Lead (CESCL) Name Organization Contact Phone Number TBD TBD TBD SWPPP Prepared By Name Organization Contact Phone Number Mary Koutrelakos Blueline 425-250-7271 SWPPP Preparation Date September 26, 2019 Project Construction Dates Activity / Phase Start Date End Date Clearing/Start May 2020 September 2021 +r"- ,mss 1. J• r k. 4 Table of Contents 1 Project Information 4 1.1 Existing Conditions 4 1.2 Proposed Construction Activities 5 2 Construction Stormwater Best Management Practices 2.1 The 13 Elements ....... . ........... ........ . . ....... .......... ............ . ........... ......... ........... ........ 6 2.1.1 Element 1: Preserve Vegetation / Mark Clearing Limits ............... ........ . .......... 6 2.1.2 Element 2: Establish Construction Access ...... ....... ...... .............. ..... 7 2.1.3 Element 3: Control Flow Rates 8 2.1.4 Element 4: Install Sediment Controls 9 2.1.5 Element 5: Stabilize Soils 11 2.1.6 Element 6: Protect Slopes 12 2.1.7 Element 7: Protect Drain Inlets 13 2.1.8 Element 8: Stabilize Channels and Outlets 14 2.1.9 Element 9: Control Pollutants 15 2.1.10 Element 10: Control Dewatering 18 2.1.11 Element 11: Maintain BMPs 20 2.1.12 Element 12: Manage the Project 21 2.1.13 Element 13: Protect Low Impact Development (LID) BMPs 24 3 Pollution Prevention Team 25 4 Monitoring and Sampling Requirements 26 4.1 Site Inspection 26 4.2 Stormwater Quality Sampling 26 4.2.1 Turbidity Sampling 26 4.2.2 pH Sampling 28 5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies 29 5.1 303(d) Listed Waterbodies 29 5.2 TMDL Waterbodies..... .... ..... ..... .......... 29 6 Reporting and Record Keeping 30 6.1 Record Keeping 30 6.1.1 Site Log Book ..... ..... .................... ..... 30 6.1.2 Records Retention 30 6.1.3 Updating the SWPPP 30 6.2 Reporting 31 6.2.1 Discharge Monitoring Reports 31 6.2.2 Notification of Noncompliance 31 Page 11 List of Tables Table 1—Summary of Site Pollutant Constituents 4 Table2—Pollutants .................................................................................................................. 15 Table3— Sources ............................................................................................... 17 Table 4— Dewatering BMPs 19 Table 5—Management 21 Table G—BK8PImplementation Schedule 22 Table 7—Team Information 25 Table 8—Turbidity Sampling Method 26 List of Appendices Append ix/G|ossary A. Site Map B.BK8PDetail C~,°orresponoenoe D'Site Inspection Form E.Construction GtVrmweterGeneral Permit /CSVVGP\ F. 303(d) List VVeterbodiva/TyWDLVVaterbmdiea Information G.Contaminated Site Information H. Engineering Calculations Page 12 / ' r . ' ` � ' ' ` ' ^ —' ` , " , r ^ ' ` r ^ ' ^ List nfAcronyms and Abbreviations Acronym /Abbreviaticn Explanation 303(d) Section of the Clean Water Act pertaining toImpaired Naterbodies BFO Bellingham Field Office oythe Department of Ecology B8*P(m) Best yWonagementPnocUne(o) CESCIL Certified Erosion and Sediment Control Lead CO2 Carbon Dioxide CRO Central Regional Office ofthe Department ofEcology CS#VGP Construction 8tmmnwatmrGeneral Permit CWA Clean Water Act 088R Discharge Monitoring Report DO Dissolved Oxygen Ecology Washington State Department ofEcology EPA United States Environmental Protection Agency ERO Eastern Regional Office mfthe Department cfEcology ERTS Environmental Report Tracking System ESC Erosion and Sediment Control GUILD General Use Level Designation NP0ES National Pollutant Discharge Elimination System NTU Nepho|omethcTurbidib/ Units NVVRO Northwest Regional Office of the Department ofEcology pH Power ofHydrogen RCW Revised Code ofWashington sPcc Spill Prevention, Control, and Countermeasure su Standard Units SWK8K8EVV 8tonnwab»rManagement Manual for Eastern Washington swYNK0VVVV GtomnwmterManagement Manual for Western Washington SWPPP StonnwntorPollution Prevention Plan TESC Temporary Erosion and Sediment Control SWFKO Southwest Regional Office ofthe Department ofEcology T88DL Total Maximum Daily Load VFO Vancouver Field Office ofthe Department ofEcology WAC Washington Administrative Code WSDOT Washington Department ofTransportation WWHK8 Western Washington Hydrology Model page 13 1 Project Information Project/Site Name: Bellwether Affordable Apartments Street/Location: 3481 S 152nd St Receiving waterbody: Gilliam Creek System/Duwamish River 1.1 Existing Conditions Total acreage (including support activities such as off -site equipment staging yards, material storage areas, borrow areas). Total Acreage 1.39 Impervious Upstream Area: 0.01 ac On -site Pervious Area: 1.29 ac Frontage Pervious Area: 0.09 ac Existing residences: 4 Topography: Site slopes north to south. The eastern portion and the south western portion of the site is developed. The south western portion is undeveloped forest land. Drainage Pattems: Surface sheet flows north to south and enters conveyance system tributary to Gilliam Creek drainage basin Existing Vegetation: undeveloped forest land List of known impairments for 303(d) or Total Maximum Daily Load (TMDL) for the receiving waterbody: Temperature, pH Critical Areas: Per the Tukwila Sensitive Areas map, the site is mapped in a landslide zone. However, after geotechnical evaluation by a licensed professional, PanGeo, Inc, areas with slopes between 15% and 40% were not identified onsite and thus will not be necessary to design for. Table 1 includes a list of suspected and/or known contaminants associated with the construction activity. See Appendix G for contaminant location map and contaminant location. Table 1 — Summary of Site Pollutant Constituents Constituent (Pollutant) Location (Remediation Area) Depth Concentration (mg/kg) Page 14 ^'' ^ . ^ r` ' 1.2 Proposed Construction Activities Description ofsite development (ex8nmp|e:aubdivisiOn): Multi -family Apartment Building Description of construction activities (example: site preparation, demolition, excavation): The projectpn}poSasconstuuobonCf87-otoryafhordab|G|hjngaoartnlertbuWdingxvith5StOhea mfliving space built above a2-otorygarage. Itwill include associated access drives, utilities, and landscaping. The project includes construction of pump station and a detention facility which will be used to ensure runoff from the developed condition matches that of the predeveloped condition. Construction activities will include site preparation, TESC installation, excavation for utilities and foundations, grading, utility installation, asphalt paving, concrete pours, and landscaping. Description of site drainage including flow from and onto adjacent properties. Must boconsistent with Site Map inAppendix A: Site drainage sheet flows southerly and is routed through a biopod to the onsite detention facility, after which it is intercepted by the City ofTukwila 12^ storm drain ayedonn installed within S 152"u 8t. Description mffinal stabilization &ouonnpk*:extent of revegetation, paving, |endacaping>: |nfinal conditions the developed site will bofully stabilized with aprivate access drive and onaboparking. {]naitelandscaping will beseeded and planted to comply with City mfBothell guidelines. Storm drainage is comprised of an enhanced water quality facility upstream of a detention vault, and a piped conveyance system that is designed to convey the 100-year rainfall event and to treat runoff per the 2016 King County Surface Water Design Manual. Contaminated Site Information: Proposed activities regarding contaminated soils orgroundwater (examnp|e:on-site treatment .^ system, authorized sanitary sewer dimoharge): None ^' /. ` ' . Pa8e IS 2 Construction Stormwater Best Management Practices (BMPs) Refer to the project's proposed TESC plans included in the Appendix A. Alternate City approved BMPs shall be utilized in the event the BMP(s) listed below are deemed ineffective or inappropriate during construction to satisfy the requirements set forth in the General NEDES Permit (Appendix C). To avoid potential erosion and sediment control issues that may cause violation(s) of the NPDES Construction Stormwater permit, the Certified Erosion and Sediment Control Lead will promptly initiate the implementation of altemative BMPs after the first sign that existing BMPs are ineffective or failing. The SWPPP is a living document reflecting current conditions and changes throughout the life of the project. These changes may be informal (i.e., hand-written notes and deletions). Update the SWPPP when the CESCL has noted a deficiency in BMPs or deviation from original design. 2.1 The 13 Elements 2.1.1 Element 1: Preserve Vegetation/Mark Clearing Limits To protect adjacent properties and to reduce the area of soil exposed to construction, the limits of construction will be clearly marked before land -disturbing activities begin. Additionally, high visibility fencing will be used to ensure that construction activities do not encroach into the 200ft Shoreline buffer at the east end of the site. The BMPs relevant to marking the clearing limits that will be applied for this project include: Applicable BMPs: • BMP C101: Preserving Natural Vegetation • BMP C102: Buffer Zones • BMP C103: High Visibility Fence Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspection to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Project arborist to be on -site during construction to ensure preservation and survivial of existing trees. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 16 r t 2.1.2 Element 2: Establish Construction Access Construction access or activities occurring on unpaved areas shall be minimized, yet where necessary, access points shall be stabilized to minimize the tracking of sediment onto public roads. Construction vehicle access and exit shall be limited to one route, if possible. Wheel washing, street sweeping, and street cleaning may be necessary if the stabilized construction access is not effective. All wash wastewater shall be controlled on site and cannot be discharged into waters of the State. If sediment is tracked off site, roads shall be cleaned thoroughly at the end of each day, or more frequently during wet weather. Sediment shall be removed from roads by shoveling or pickup sweeping and shall be transported to a controlled sediment disposal area. Applicable BMPs: • BMP C105: Stabilized Construction Entrance/Exit • BMP C106: Wheel Wash • BMP C107: Construction Road/parking Area Stabilization. Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspection to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 17 2.1.3 Element 3: Control Flow Rates In order to protect the properties and waterways downstream of the project site, stormwater discharges from the site will be controlled. In general, discharge rates of stormwater from the site will be controlled where increases in impervious area or soil compaction during construction could lead to downstream erosion, or where necessary to meet local agency stormwater discharge requirements (e.g. discharge to combined sewer systems) Will you construct stormwater retention and/or detention facilities? Yesilli No Will you use permanent infiltration ponds or other low impact development (example: rain gardens, bio-retentson, porous pavement) to control flow during construction? 111 Yes No Initially, temporary sediment traps will be installed per Section 2.1.4 (below). Runoff will then be routed to the detention facilities before entering the public storm main. Applicable BMPs: • BMP C200: Interceptor Dikes and Swales • BMP C207: Check Dams • BMP C233: Silt Fence • BMP C240: Sediment Trap Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 18 2.1.4 Element 4: Install Sediment Controls All stormwater runoff from disturbed areas shall pass through appropriate sediment removal BMPs before leaving the construction site. BMPs will be constructed as one of the first steps of grading and will be functional before other land disturbing activities take place. In addition, sediment will be removed from paved areas in and adjacent to construction work areas manually or using mechanical sweepers, as needed, to minimize trackkig of sediments on vehicle tires away from the site and to minimize washoff of sediments from adjacent streets in runoff. When permanent stormwater BMPs will be used to control sediment discharge during construction, the structure will be protected from excessive sedimentation with adequate erosion and sediment control BMPs. Any accumulated sediment shall be removed after construction is complete and the permanent stormwater BMP will be restabilized with vegetation per applicable design requirements once the remainder of the site has been stabilized. Applicable BMPs: BMP C200: Interceptor Dikes and Swales BMP C207: Check Dams BMP C220: Storm Drain Inlet Protection BMP C233: Silt Fence BMP C240: Sediment Trap A sediment trap will be utilized for the majority of the onsite disturbed area. The surface area for the sediment trap was determined by calculating the runoff rate of the 2-year return period (0.4792 cfs). Yielding a required 996.74(0.023 acres) of surface trap area per the KCSWDM. WWHM Flow Frequency Output: Flow(cfs) Predeveloped Unmitigated 2 Year 0.0409 0.4792 5 Year 0.0642 0.6088 10 Year 0.0774 0.6973 25 Year 0.0914 0.8124 50 Year 0.1001 0.9008 100 Year 0.1074 0.9915 SArequired =2080/cfs of inflow = 2080 x 0.4792 = 996.74 sf The TESC plan will provide 1000 sf of sediment trap area. See the following pages for the WWHM calculations and Appendix B for TESC details. See Appendix B for TESC details. Page 19 Determining Riser Dimensions: Dewatering Orifice Area = A, (in2) = 1.441N. per cfs of inflow Where h = head of water above orifice in feet Area = 0.4792 cfs x 2.694 = 1.291 in2 Diameter = D (in) = 1.13/K, D = 1.13 (1/1.291)= 1.28" Use 1.30" 0 Dewatering Orifice for trap. Use 4" 0 Polyethylene Drainage Tubing or nearest size larger than 9" Determined using Figure 3.5 in Appendix H Use 12" 0 corrugated metal riser for sediment trap. Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 110 r • _4 2.1.5 Element 5: Stabilize Soils Exposed and unworked soils shall be stabilized with the application of effective BMPs to prevent erosion throughout the life of the project. In general, cut and fill slopes will be stabilized as soon as possible and soil stockpiles will be temporarily covered with plastic sheeting. All stockpiled soils shall be stabilized from erosion, protected with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. Earthwork quantities: 8,950 CY Cut / 300 CY Fill West of the Cascade Mountains Crest Season Dates Number of Days Soils Can Be Left Exposed During the Dry Season May 1 — September 30 7 days During the Wet Season October 1 — April 30 2 days Soils must be stabilized at the end of the shift before a holiday or weekend if needed based on the weather forecast. r ' Anticipated project dates: Start date: 05/2020 End date: 09/2021 41 • Will you construct during the wet season? Eli Yes E No Applicable BMPs: Element 5: Stabilize Soils: • BMP C120: Temporary and Permanent Seeding • BMP C121: Mulching • BMP C123: Plastic Covering • BMP C130: Surface Roughening • BMP C140: Dust Control • Early application of gravel base on areas to be paved Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 1ll 2.1.6 Element 6: Protect Slopes Will steep slopes be present at the site during construction? Lill YesN No Cut and fill slopes within the site will be designed, constructed, and protected in a manner that minimizes erosion. The BMPs to be used to protect slopes for this project are listed below. Applicable BMPs: • BMP C120: Temporary and Permanent Seeding • BMP C121: Mulching • BMP C123 Plastic Covering • BMP C130: Surface Roughening Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 112 2.1.7 Element 7: Protect Drain Inlets All storm drain inlets and culverts made operable during construction shall be protected to prevent unfiltered or untreated water from entering the drainage conveyance system. The priority, however, will be to keep all access roads clean of sediment and keep street wash water from entering storm drains until treatment can be provided. Inlet protection will be implemented for all drainage inlets and culverts that could potentially be impacted by sediment -laden runoff on and near the project site. The following inlet protection measures will be applied on this project: Applicable BMPs: • BMP C220: Storm Drain Inlet Protection Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page I 13 2.1.8 Element 8: Stabilize Channels and Outlets Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent stream banks, slopes, and downstream reaches, will be installed at the outlets of all conveyance systems. Where site runoff is to be conveyed in channels or discharged to a stream or some other natural drainage point, efforts will be taken to prevent downstream erosion. The specific BMPs for Applicable BMPs: • Check Dams (BMP C207) • Outlet Protection (BMP C209) Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 114 ^ _ � .� .� ' r� `/ 2.1.9 Element 9: Control Pollutants The following pollutants are anticipated to be present on -site: Table 2-Pollutants Pollutant (List pollutants and source, if applicable) Concrete Diesel Fuel (remove |believe) Asphal Building, insulation, and roofing materials All pollutants, including waste materials and demolition debris, that occur onsite shall be handled and disposed of in a manner that does not cause contamination of stormwater. Good housekeeping and preventative measures will bataken 'to ensure that the site will bekept clean, vve||+JrQaniZed, and free of debris. If required, 8K8Ps to be implemented to control specific sources Cfpollutants are discussed below. Chemical storage: = Any chemicals stored in the umnatnuotknl areas will conform to the appropriate source control BMPs listed in Volume IV of the Ecology stormwater manual. In Western WA, all chemicals shall have cover, containment, and protection provided on site, perByNP C153for Material Oe|ivery, Storage and Containment inGVVK8MWVV2OO5 � Application cfagricultural chemicals, including fertilizers and pesticides,shall bm conducted in a manner and at apo|kzyUon rates that will not result in loss of chemical to stormwater runoff. Manufacturers' recommendations for application procedures and rates shall be followed, Excavation and tunneling spoils devvatehnQwaste: Demolition: � OavvotehngBK8Psand BK8Ps specific tothe excavation and tunneling (including handling of contaminated soils) are discussed under Element 10. � Dust released from demolished sidewalks, buildings, orstructures will ba controlled using Dust Control measures (BMP C140). � Storm drain inlets vulnerable hzatornlwaLardischarge carrying dust, soil, or debris will be protected using Storm Drain |n|m{ PnJhscUmn (BK8P C220 as • Process water and slurry resulting from saw cutting and surfacing operations will be prevented from entering the waters of the State by implementing Sawcutting and Surfacing Pollution Prevention measures (BMP C152). Concrete and grout: Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling measures (BMP C151). Concrete wash out areas shall not be allowed on bare dirt or allowed to drain to bare dirt or the storm system. Sanitary wastewater: Portable sanitation facilities will be firmly secured, regularly maintained, and emptied when necessary. • Wheel wash or tire bath wastewater shall be discharged to a separate onsite treatment system or to the sanitary sewer as part of Wheel Wash implementation (BMP C106). Solid Waste: • Solid waste will be stored in secure, clearly marked containers. Other: Other BMPs will be administered as necessary to address any additional pollutant sources on site. Installation Schedules: Start of project and replaced as needed and as start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Will maintenance, fueling, and/or repair of heavy equipment and vehicles occur on -site? El Yes No Vehicles, construction equipment, and/or petroleum product storage/dispensing: All vehicles, equipment, and petroleum product storage/dispensing area swill be inspected regularly to detect any leaks or spills, and to identify maintenance needs to prevent leaks or spills. On -site fueling tanks and petroleum product storage containers shall include secondary containment. Page 116 r7 • • Spill prevention measures, such as drip pans, will be used when conducting maintenance and repair of vehicles or equipment. • In order to perform emergency repairs on site, temporary plastic will be placed beneath and, if raining, over the vehicle. • Contaminated surfaces shall be cleaned immediately following any discharge or spill incident. Applicable BMPs: • Material Delivery, Storage and Containment (BMP C153) Fuel onsite will be comprised of fuel tanks in operating equipment ranging between 50-100 gallons of off road diesel fuel. The BMPs listed below as well as procedures described above should be followed with refueling equipment. Spill kits should be kept on hand and accessible during refueling activates. Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to rnake weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Will wheel wash or tire bath system BMPs be used during construction? ❑ Yes® No Will pH -modifying sources be present on -site? Yes❑ No Table 3 — pH -Modifying Sources ❑ None ❑ Bulk cement ❑ Cement kiln dust ❑ Fly ash // Other cementitious materials ❑ New concrete washing or curing waters ❑ Waste streams generated from concrete grinding and sawing ❑ Exposed aggregate processes ❑ Dewatering concrete vaults ❑ Concrete pumping and mixer washout waters ❑ Recycled concrete ❑ Recycled concrete stockpiles ❑ Other (i.e., calcium lignosulfate) [please describe] Page 117 Applicable BMPs: Monitoring should be performed to ensure concrete placement does not result in excessively high pH in stormwater runoff. pH testing should be performed on a weekly basis, from the start of concrete work until pH drops below 8.5 su. Concrete ard grout: • Process water and slurry resulting from concrete work will be prevented from entering the waters of the State by implementing Concrete Handling measures (BMP C151). Concrete wash out areas shall not be allowed on bare dirt or allowed to drain to bare dirt or the storm system. Installation Schedules: Start of project and replaced as needed and at start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Adjust pH of stormwater if outside the range of 6.5 to 8.5 su. Obtain written approval from Ecology before using chemical treatment with the exception of CO2 or dry ice to modify pH. Concrete trucks must not be washed out onto the ground, or into storm drains, open ditches, streets, or streams. Excess concrete must not be dumped on -site, except in designated concrete washout areas with appropriate BMPs installed. Will uncontaminated water from water -only based shaft drilling for construction of building, road, and bridge foundations be infiltrated provided the wastewater is managed in a way that prohibits discharge to surface waters? El Yes No 2.1.10 Element 10: Control Dewatering All dewatering water from open cut excavation, tunneling, foundation work, trench, or underground vaults shall be discharged into a controlled conveyance system prior to discharge to a sediment trap or sediment pond. Channels will be stabilized, per Element #8. Page 118 ') f Clean, non -turbid dewatering water will not be routed through stormwater sediment ponds, and will not be discharged to systems tributary to the receiving waters of the State in a manner that does no cause erosion, flooding, or a violation of State water quality standards in the receiving water. Highly turbid dewatering water from soils known or suspected to be contaminated, or from use of construction equipment, will require additional monitoring and treatment as required for the specific pollutants based on the receiving waters into which the discharge is occurring. Such monitoring is the responsibility of the contractor. Dewatering of soils known to be free of contamination will trigger BMPs to trap sediment and reduce turbidity. Other BMPs to be used for sediment trapping and turbidity reduction include the following. Table 4 — Dewatering BMPs Infiltration LI Transport off -site in a vehicle (vacuum truck for legal disposal) LI Ecology -approved on -site chemical treatment or other suitable treatment echnologies Sanitary or combined sewer discharge with IocaI sewer district approval as resort) 1. Use of sedimentation bag with discharge to ditch or swale (small volumes of localized dewatering) Installation Schedules: Start of project and replaced as needed and as start of wet season. Inspection and Maintenance plan: Responsible staff to make weekly site walks and inspections to identify deficiencies in onsite BMPs and anticipate potential problems and remedies. Responsible Staff: Identified Certified Erosion and Sediment Control Lead in Section 3 of this SWPPP. Page 119 2.1.11 Element 11: Maintain BMPs All temporary and permanent Erosion and Sediment Control (ESC) BMPs shall be maintained and repaired as needed to ensure continued performance of their intended function. Maintenance and repair shall be conducted in accordance with each particular BMP specification (see Volume 11 of the SWMMWW or Chapter 7 of the SWMMEW). Visual monitoring of all BMPs installed at the site wilt be conducted at least once every calendar week and within 24 hours of any stormwater or non-stormwater discharge from the site. If the site becomes inactive and is temporarily stabilized, the inspection frequency may be reduced to once every calendar month. All temporary ESC BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. Trapped sediment shall be stabilized on -site or removed. Disturbed soil resulting from removal of either BMPs or vegetation shall be permanently stabilized. Additionally, protection must be provided for all BMPs installed for the permanent control of stormwater from sediment and compaction. BMPs that are to remain in place following completion of construction shall be examined and restored to full operating condition. If sediment enters these BMPs during construction, the sediment shall be removed and the facility shall be retumed to conditions specified in the construction documents. Page 120 1. A A 2.1.12 Element 12: Manage the Project The project will be managed based on the following principles: • Projects will be phased to the maximum extent practicable and seasonal work limitations will be taken into account. • Inspection and monitoring: o Inspection, maintenance and repair of all BMPs will occur as needed to ensure performance of their intended function. o Site inspections and monitoring will be conducted in accordance with Special Condition S4 of the CSWGP. Sampling locations are indicated on the Site Map. Sampling station(s) are located in accordance with applicable requirements of the CSWGP. • Maintain an updated SWPPP. o The SWPPP will be updated, maintained, and implemented in accordance with Special Conditions S3, 54, and S9 of the CSWGP. As site work progresses the SWPPP will be modified routinely to reflect changing site conditions. The SWPPP will be reviewed monthly to ensure the content is current. Check all the management BMPs that apply at your site: Table 5 — Management Design the project to fit the existing topography, soils, and drainage patterns fl Emphasize erosion controlrather than sediment control Minimize the extent and duration of the area exposed Keep runoff velocities low fl Retain sediment on -site C Thoroughly monitor site and maintain all ESC measures ScheduleLJ major earthwork during the dry season LJ Other (please describe) Page 121 Optional: Fill out Table 6 by listing the BMP associated with specific construction activities. Identify the phase of the project (if applicable). To increase awareness of seasonal requirements, indicate if the activity falls within the wet or dry season. Table 6 — BMP Implementation Schedule Phase of Construction Project Stormwater BMPs Date Wet/Dry Season [Insert constructioin activity] [Insert BMP] [MM/DD/YYYY] [Insert Season] Page I 22 A.. A ti 7 r 4 4 • Phase of Construction Project Stormwater BMPs Date [Insert construction activity] [Insert BMP] [MM/DD/YYYY] Wet/Dry Season [Insert Season] Page I 23 2.1.13 Element 13: Protect Low Impact Development (LID) BMPs The LID facilities are to be protected from sedimentation through installation and maintenance of erosion and sediment control BMPs on portions of the site that drain to the LID BMPs. The existing soils under LID facilities are to be protected against compaction by construction equipment and foot traffic in order to maintain their infiltration capability. Permittees must keep all heavy equipment off LID facilities that have been excavated to final grade to retain the infiltration rate of the soils. If infiltration area is compacted during construction, area shall be scarified to a depth of 12 inches below the infiltration facility bottom elevation. Page 124 J 7 7 3 Pollution Prevention Team Table 7 — Team Information Title Name(s) Phone Number Certified Erosion and Sediment Control Lead (CESCL) TBD TBD Resident Engineer Chris Miller, PE (425) 250-7249 Emergency Ecology Contact Rachel McCrea (425) 649-7076 Emergency Permittee/ Owner Contact Emma Geyer (206-588-4821 Non -Emergency Owner Contact Emma Geyer (206-588-4821 Monitoring Personnel TBD TBD Ecology Regional Office Northwest Region (425) 649-7000 Page 125 4 Monitoring and Sampling Requirements Monitoring includes visual inspection, sampling for water quality parameters of concern, and documentation of the inspection and sampling findings in a site log book. A site log book will be maintained for all on -site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Stormwater sampling data See form in Appendix D The site log book must be maintained on -site within reasonable access to the site and be made available upon request to Ecology or the local jurisdiction. Numeric effluent limits may be required for certain discharges to 303(d) listed waterbodies. See CSWGP Special Condition S8 and Section 5 of this template. 4.1 Site Inspection Site inspections will be conducted at least once every calendar week and within 24 hours following any discharge from the site. For sites that are temporarily stabilized and inactive, the required frequency is reduced to once per calendar month. The discharge point(s) are indicated on the Site Map (see Appendix A) and in accordance with the applicable requirements of the CSWGP. 4.2 Stormwater Quality Sampling 4.2.1 Turbidity Sampling Requirements include calibrated turbidity meter or transparency tube to sample site discharges for compliance with the CSWGP. Sampling will be conducted at all discharge points at least once per calendar week. Method for sampling turbidity: Table 8 — Turbidity Sampling Method [1] Turbidity Meter/Turbidimeter (required for disturbances 5 acres or greater in size) Transparency Tube (option for disturbances less than 1 acre and up to 5 acres in size) The benchmark for turbidity value is 25 nephelometric turbidity units (NTU) and a transparency less than 33 centimeters. If the discharge's turbidity is 26 to 249 NTU or the transparency is less than 33 cm but equal to or greater than 6 cm, the following steps will be conducted: 1. Review the SWPPP for compliance with Special Condition S9. Make appropriate revisions within 7 days of the date the discharge exceeded the benchmark. Page 1 26 r •L : • r 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period. 3. Document BMP implementation and maintenance in the site log book. If the turbidity exceeds 250 NTU or the transparency is 6 cm or less at any time, the following steps will be conducted: 1. Telephone or submit an electronic report to the applicable Ecology Region's Environmental Report Tracking System (ERTS) within 24 hours. • Central Region (Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, Yakima): (509) 575-2490 or htto://www.ecy.wa.gov/programs/spills/forms/nerts online/CRO nerts online.html • Eastern Region (Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, Whitman): (509) 329-3400 or htto://www.ecy.wa.gov/programs/spills/forms/nerts online/ERO nerts online.html • Northwest Region (King, Kitsap, Island, San Juan, Skagit, Snohomish, Whatcom): (425) 649-7000 or htto://vvww.ecy.wa.gov/procirams/spills/forms/nerts online/NWRO nerts online.html Southwest Region (Clallam, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, Wahkiakum,): (360) 407-6300 or http://~N.ecy.wa.qov/oroarams/soills/forms/nerts online/SWRO nerts online.html 2. Immediately begin the process to fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible. Address the problems within 10 days of the date the discharge exceeded the benchmark. If installation of necessary treatment BMPs is not feasible within 10 days, Ecology may approve additional time when the Permittee requests an extension within the initial 10-day response period 3. Document BMP implementation arid maintenance in the site log book. 4. Continue to sample discharges daily until one of the following is true: • Turbidity is 25 NTU (or lower). • Transparency is 33 cm (or greater). • Compliance with the water quality limit for turbidity is achieved. O 1 - 5 NTU over background turbidity, if background is less than 50 NTU O 1°/0 - 10°/0 over background turbidity, if background is 50 NTU or greater • The discharge stops or is eliminated. Page I 27 4.2.2 pH Sampling pH monitoring is required for "Significant concrete work" (i.e., greater than 1000 cubic yards poured concrete over the life of the project). The use of recycled concrete or engineered soils (soil amendments including but not limited to Portland cement -treated base [CTB], cement kiln dust [CKD] or fly ash) also requires pH monitoring. For significant concrete work, pH sampling will start the first day concrete is poured and continue until it is cured, typically three (3) weeks after the last pour. For engineered soils and recycled concrete, pH sampling begins when engineered soils or recycled concrete are first exposed to precipitation and continues until the area is fully stabilized. If the measured pH is 8.5 or greater, the following measures will be taken: 1. Prevent high pH water from entering storm sewer systems or surface water. 2. Adjust or neutralize the high pH water to the range of 6.5 to 8.5 su using appropriate technology such as carbon dioxide (CO2) sparging (liquid or dry ice). 3. Written approval will be obtained from Ecology prior to the use of chemical treatment other than CO2 sparging or dry ice. Method for sampling pH: Table 9 — pH Sampling Method El pH meter pH test kit Wide range pH indicator paper ' To be determined Page 128 I 5 Discharges to 303(d) or Total Maximum Daily Load (TMDL) Waterbodies 5.1 303(d) Listed Waterbodies Is the receiving water 303(d) (Category 5) listed for turbidity, fine sediment, phosphorus, or pH? YesE No List the impairment(s): pH 5.2 TMDL Waterbodies Waste Load Allocation for CWSGP discharges: Describe the method(s) for TMDL compliance: List and describe BMPs: BMP C253: pH Control for High pH Water Discharges to TMDL receiving waterbodies will meet in -stream water quality criteria at the point of discharge. The Construction Stormwater General Permit Proposed New Discharge to an Impaired Water Body form is included in Appendix F. Page 129 6 Reporting and Record Keeping 6.1 Record Keeping 6.1.1 Site Log Book A site log book will be maintained for all on -site construction activities and will include: • A record of the implementation of the SWPPP and other permit requirements • Site inspections • Sample logs 6.1.2 Records Retention Records will be retained during the life of the project and for a minimum of three (3) years following the termination of permit coverage in accordance with Special Condition S5.0 of the CSWGP. Permit documentation to be retained on -site: • CSWGP • Permit Coverage Letter • SWPPP • Site Log Book Permit documentation will be provided within 14 days of receipt of a written request from Ecology. A copy of the SWPPP or access to the SWPPP will be provided to the public when requested in writing in accordance with Special Condition S5.G.2.b of the CSWGP. 6.1.3 Updating the SWPPP The SWPPP will be modified if: • Found ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. • There is a change in design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the State. The SWPPP will be modified within seven (7) days if inspection(s) or investigation(s) determine additional or modified BMPs are necessary for compliance. An updated timelune for BMP implementation will be prepared. Page 130 r 3 6.2 Reporting 6.2.1 Discharge Monitoring Reports Cumulative soil disturbance is one (1) acre or larger; therefore, Discharge Monitoring Reports (DMRs) will be submitted to Ecology monthly. If there was no discharge during a given monitoring period the DMR will be submitted as required, reporting "No Discharge". The DMR due date is fifteen (15) days following the end of each calendar month. DMRs will be reported online through Ecology's WQWebDMR System. To sign up for WQWebDMR go to: http://www.ecv.wa.00v/proorams/wo/permits/paris/webdmr.html 6.2.2 Notification of Noncompliance If any of the terms and conditions of the permit is not met, and the resulting noncompliance may cause a threat to human health or the environment, the following actions will be taken: 1. Ecology will be notified within 24-hours of the failure to comply by calling the applicable Regional office ERTS phone number (Regional office numbers listed below). 2. Immediate action will be taken to prevent the discharge/pollution or otherwise stop or correct the noncompliance. If applicable, sampling and analysis of any noncompliance will be repeated immediately and the results submitted to Ecology within five (5) days of becoming aware of the violation. 3. A detailed written report describing the noncompliance will be submitted to Ecology within five (5) days, unless requested earlier by Ecology. Specific information to be included in the noncompliance report is found in Special Condition S5.F.3 of the CSWGP. Anytime turbidity sampling indicates turbidity is 250 NTUs or greater, or water transparency is 6 cm or less, the Ecology Regional office will be notified by phone within 24 hours of analysis as required by Special Condition S5.A of the CSWGP. • Central Region at (509) 575-2490 for Benton, Chelan, Douglas, Kittitas, Klickitat, Okanogan, or Yakima County • Eastern Region at (509) 329-3400 for Adams, Asotin, Columbia, Ferry, Franklin, Garfield, Grant, Lincoln, Pend Oreille, Spokane, Stevens, Walla Walla, or Whitman County • Northwest Region at (425) 649-7000 for Island, King, Kitsap, San Juan, Skagit, Snohomish, or Whatcom County • Southwest Region at (360) 407-6300 for Clallann, Clark, Cowlitz, Grays Harbor, Jefferson, Lewis, Mason, Pacific, Pierce, Skamania, Thurston, or Wahkiakum Page 131 Include the following information: 1. Your name and / Phone number 2. Permit number 3. City / County of project 4. Sample results 5. Date / Time of call 6. Date / Time of sample 7. Project name In accordance with Special Condition S4.D.5.b of the CSWGP, the Ecology Regional office will be notified if chemical treatment other than CO2 sparging is planned for adjustment of high pH water. Page 132 Appendix/Glossary A. Site Map (insert TESL Plan) Page 133 NE 1/4, SW 1/4, SEC 22, TWP 23 N, RGE 4 E, W.M. 12 CD AECB2, PR., 26 2 2' 2 ON IE.32S900,) 'tor; (E) NWT DP row ON CO 56 PROCIX 12 216096, 7r4C FIN 11.246 tl'CPC IE 5307I lf) EX C6 ANllfl I793i Rv 7150 CONC & J764i (7) I 2 N1J2165 (17 72'PK432i851S) 72 51 A J2314 (P) v. ss ti 0Cti51HOCDCNfiNEE (4P) CONS)'ICApI 11(( aAM P) EAD7N LAS PN731 34BI76CNTRP' DOS wl6318 SST ( V M it 6 i"WJYN4 Ai II 7 ✓, 6011g1%4A342 J71S 10 l i • N' R4a2 �� Eto--- ' 21 RA I4Pf POUND 4M4 J29A G7520t44620 ACCST WItl4E RCSro46A4 Mll4R06N 1/PR, 1224486I47OAE VAR 5 1160494g 20001AAP ACV KM VW ro 42E12004v Nar. OUR 6451 Eur 7WU25 7K577A TOP 7 ;7 10EJ717O SCALE: 1" = 20' 0 10 20 40 TREE LEGEND U,514C 144E TOEEMOM C IPSTA4AN(E 144E TOG* `..%\pry9CUROJEra4 LEGEND TESL FCAT2RCS — 4--400 Ri8K4 •• MEM SWALE 4ARk86 after AMMO MORE 18EARePREP iiWOOF ORM A 4APo'G128419N 4URCroI OM Cp57494094SW( p KO04Ed OAP ® AI6IRARIRALP VGi5OY UNDERGROUND UTILITY NOTE UNO<'RGROUND U7NIDES ARE SON N THE APPRO.t14A1E LOMA WE IS N0 GUARANTEE IHA7 All PO UNIT ARE SHOW OP 1NA1 THE IOCAPO{ SUE MO 41ERIP1 IS A07A6AIC 1NE (DRAM Nil MOB All ROUTED WING W*RE NOW INf[RE8REh'Q3, OP GA`E4CRCNS GCfUR PRY 70 IMAOII6G OR EOGVARON FOR ANY PR' OR 515JCMPES, TO DEIERIONE ACNAI 10CAROVS, 220E AND 10117I)1 T4 CONTRACTOR 401All RAKE 70 APPRORAAIE ARGON FOR PROif67CW OT SRO FAME THE CONTRACTOR 7(Pll NOTIFY QL 8LL A18-I-1(WA22IXN07CNERI.00Y) AND AWE FOR MD 1XATTON or EA15RN0 FAMES FORE DRUM, A 1, BLUELINE uu r,7eN 6460 i44811.41 11544111Eg64AW SOIL ASN TED PR0EC74ANAOER: 0[t57Tg N 65585 a PRG,ECI ENGNEEB aEPOMOa MSGNCA: 66464 A026646A ISSU DAIS' 2/5/NAP 9/14119 108 NVNBER: 18.183 SHEETNAME: TP•D 1 $MT 3 DF 6 CM D4CC* OiOuw NE 1/4, SW 1/4, SEC 22, TWP 23 N, RGE 4 E, W.M. 057 TYPE I Rao )27 25 ,212162,E J25.96 (w) ,2E: 32W (E) 18'21 21828 AR II I I I' T I TA II oi4 IS I i DISCIoREE Mr EQR ORANTITIC I OF REDO RUT AMC AS RE XV E 8,4ASTIARR E DOES NOT `SEDIMENT PERt CSOITRACTOR 10 rEAI 0 E I'D 25 81: 1 I ii, T 8 8,1 Ts / i7,4 tom 4 : I 1672167847 WINN Clit PRO ROCK OM( 780 II 1, cavc ,E DWG 72 I I IQ III, IFN5. 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Mil 6 8094040880798807410 411. MN, 07 NAT Pff 1.01104 SII AND MATRAL 6 ACCXATE. GOVTR)CTY SVC moo Al *GCB AVG met MG, INTRO= OR mews ow PRIX FO TRW% OR [SWOON PDF ANY Pet OR SKIM TO TOW ACTUAL LOCAPC46 SE AC MAIERIL 51080878117789880 NAKE 08108880840110 PRONSAV FGF FROIECTIX X SND FOUTS PlE CCHIRACTOR SHALL NOISY crifja AT 8-I-1 (wA90210I848811a) AND ARRANGE FOR MD LOGAIION WING FACIOES COVSTPUCTIOV. A BLUELINE 2.I.VANSIATE4 MIJNON 1,421601 P125.216= mo,HaL:anuounal pRolcr ONAGER: MD II iN Ilia Ff PRIECT ACKER824289408440 077587/ vA ISSUE DA1E: 9/26/DI 9/10 JOB NUMBER. 18-163 WET NAME TP.02 SHT 4 or 6 • DIE DSTANCO510 MATPDNAA ANOB ARFCfENAp1VA1OA. LA CHECK DAM SPACING SECTION A.A NO M t PRONOERD XVDAUSEBYMR OREIL9r2FE Ci MRTICAEfALL 2 ANY.4WISTDEPORa4 TOE NANOr AV 0R $ Fr. ECBO OSO WI MENAME ASS ONO TO ITS NMI WSON WAXY. MEmIMHEI SW. BF MIMEO ttR9CWS D'%'WAMD AND ER09044ME EEO ANOPAK PSCOOPX CR ROO MS OGWOED, AMMO AROX MIKPROTECTED BYRIP-RAP ARAN&OXON CO MY MT M[ 4. 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NU SRAII PRO'AYNEfRMAIDYFOR WORRY ERAO MEAA@SrAO,6MG41C 114 DMNCALL RIASESS CAYSRNC)EM AAD 911E PROM 49114NRTSTADUZAMNFIR DISIMAKAf ON CIWSIRUCD4DIEDOTYMAYREN / A00a4E OWES ASNFE[ND N Wei E AA'A4O RETAUDRYNT B RIFPUS 9011EMMASkERT9T TL4TC RCM RIM 5FO0&NrCNiAW At091A1i MMAd1E MEEYSMANM WNAfiAvISOR MOODATDMDA ME PLAN MALL Ma VW COMFSMA REtAiNMAW N-91, ATA ROUX DiLSCPLM9XI 9DMUAW LNMS5EN9RMARCA 51750 AA;9A PRONK WARY SAMlUApX55505 R1MMNIIX AND POWER PROQC OAMOK PRAXIS IL ROOWRCSTAMAIM NOUNS AND SU.RFAX WIRCANIRNS MI td SIAN EN MCM4V/N, INXXSAU!ALSO PRPAIX WWR O dIMM MOO REIMWS MEPLO SY&PROOF THE SEED NIYFOR RE iEWORRYAWPRAtif .000G E PUteNSWL ROW COVENTA91AC5ASFMK Al MA MjANYVag ANA51177u4Y(Awt0 407 Y0N M44,1044159049 MI Z NAY IA4424:4 ODRAX1E19X0rM01CR44549Wls *MUM DIElAHAS!(Rwow raw! h sr am S OMB 1MRNNs AR JA MMWUM Er VA 104,991 t A6iAl WARY OMRITANSS NXi PREIS Ng MU Raflai MOW FOR MORE MANfkO0ArsAND N MORES STET CUT M0OIL Da 4 RFT44 ChM A GUMDTYCP NKRNEAWFfSWBUS ARROW TO COMRALL DSMR&DAREAS c EYCCTctl81EARP7ARYSEEO ANO MAIN AU AREAS THAT MU 85@AA[R400ENG ME E711S4t1 d MAWMl SEW AREAS a NAME 4ll CANSIRUM44 TRAM Mfg tw4EPSM4f4040441401 UNDERGROUND UTILITY NOTE XXXPGROUND OUTS ARE 94011E AY INE ARPROSATE LOGfl4S PORE IS NO GUARANTEE MAT All MEATY UNES ARE MAN, OR INAT ME LOC4R01l SZE AND MARERI4! IS ACCURATE ME C44WAC7AR 9EAfl UNCOVER ALL BROGTED RRNC *OE ON70N4 INIERFEFt0Y 77 AP CG44f2RCM PXUR PCP TO IREN6NAV6 OR DCAVARCW FAR ANY PPE OR SWIM TO MINE ACTUAL LOCAIIGNS, SZE MO MATERIAL 18E CAV0RAC7AP 91,111 MAKE ITS APPROPRIATE PRON9C14 FAR PROICCR2N OF SAID FAME THE CCARACTOR 9UU NOTIFY 04L24LL AT 8-1-I (MA94MG7DN811.GOM) AND ARRANGE FOR FHID LOGAMM G EARSENG (IIlI,gU a(07E CONS RUCIIN BLUELINE p.13tMNil P,,L316 PROA'C7MANAGE 040704ERN NWE PPOMCi ENG4VEE AYL 0040041E DE9r>NfR: NADAA9tlADVA ISSU DATE: P/M/107P 0 9/I6/19 JOB NUMBER: 18.183 5MEETNAME: TD•01 Cr 6 B. BMP Detail Page 134 BMP C101: Preserving Natural Vegetation Purpose Conditions of Use The purpose of preserving natural vegetation is to reduce erosion wherever practicable. Limiting site disturbance is the single most effective method for reducing erosion. For example, conifers can hold up to about 50 percent of all rain that falls during a storm. Up to 20-30 percent of this rain may never reach the ground but is taken up by the tree or evaporates. Another benefit is that the rain held in the tree can be released slowly to the ground after the storm. Natural vegetation should be preserved on steep slopes, near perennial and intermittent watercourses or swales, and on building sites in wooded areas. • As required by local governments. • Phase construction to preserve natural vegetation on the project site for as long as possible during the construction period. Design and Natural vegetation can be preserved in natural clumps or as individual Installation trees, shrubs and vines. Specifications The preservation of individual plants is more difficult because heavy equipment is generally used to remove unwanted vegetation. The points to remember when attempting to save individual plants are: • Is the plant worth saving? Consider the location, species, size, age, vigor, and the work involved. Local governments may also have ordinances to save natural vegetation and trees. • Fence or clearly mark areas around trees that are to be saved. It is preferable to keep ground disturbance away from the trees at least as far out as the dripline. Plants need protection from three kinds of injuries: • Construction Equipment - This injury can be above or below the ground level. Damage results from scarring, cutting of roots, and compaction of the soil. Placing a fenced buffer zone around plants to be saved prior to construction can prevent construction equipment injuries. • Grade Changes - Changing the natural ground level will alter grades, which affects the plant's ability to obtain the necessary air, water, and minerals. Minor fills usually do not cause problems although sensitivity between species does vary and should be checked. Trees can typically tolerate fill of 6 inches or less. For shrubs and other plants, the fill should be less. When there are major changes in grade, it may become necessary to supply air to the roots of plants. This can be done by placing a layer of gravel and a tile system over the roots before the fill is made. A tile Volume II — Construction Stormwater Pollution Prevention - December 2014 4-3 system protects a tree from a raised grade. The tile system should be laid out on the original grade leading from a dry well around the tree trunk. The system should then be covered with small stones to allow air to circulate over the root area. Lowering the natural ground level can seriously damage trees and shrubs. The highest percentage of the plant roots are in the upper 12 inches of the soil and cuts of only 2-3 inches can cause serious injury. • To protect the roots it may be necessary to terrace the immediate area around the plants to be saved. If roots are exposed, construction of retaining walls may be needed to keep the soil in place. Plants can also be preserved by leaving them on an undisturbed, gently sloping mound. To increase the chances for survival, it is best to limit grade changes and other soil disturbances to areas outside the dripline of the plant. • Excavations - Protect trees and other plants when excavating for drainfields, power, water, and sewer lines. Where possible, the trenches should be routed around trees and large shrubs. When this is not possible, it is best to tunnel under them. This can be done with hand tools or with power augers. If it is not possible to route the trench around plants to be saved, then the following should be observed: Cut as few roots as possible. When you have to cut, cut clean. Paint cut root ends with a wood dressing like asphalt base paint if roots will be exposed for more than 24-hours. Backfill the trench as soon as possible. Tunnel beneath root systems as close to the center of the main trunk to preserve most of the important feeder roots. Some problems that can be encountered with a few specific trees are: • Maple, Dogwood, Red alder, Western hemlock, Western red cedar, and Douglas fir do not readily adjust to changes in environment and special care should be taken to protect these trees. The windthrow hazard of Pacific silver fir and madrona is high, while that of Western hemlock is moderate. The danger of windthrow increases where dense stands have been thinned. Other species (unless they are on shallow, wet soils less than 20 inches deep) have a low windthrow hazard. • Cottonwoods, maples, and willows have water -seeking roots. These can cause trouble in sewer lines and infiltration fields. On the other hand, they thrive in high moisture conditions that other trees would not. • Thinning operations in pure or mixed stands of Grand fir, Pacific silver fir, Noble fir, Sitka spruce, Western red cedar, Western hemlock, Pacific dogwood, and Red alder can cause serious disease problems. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-4 Disease can become established through damaged limbs, trunks, roots, and freshly cut stumps. Diseased and weakened trees are also susceptible to insect attack. Maintenance Inspect flagged and/or fenced areas regularly to make sure flagging or Standards fencing has not been removed or damaged. If the flagging or fencing has been damaged or visibility reduced, it shall be repaired or replaced immediately and visibility restored. • If tree roots have been exposed or injured, "prune" cleanly with an appropriate pruning saw or loppers directly above the damaged roots and recover with native soils. Treatment of sap flowing trees (fir, hemlock, pine, soft maples) is not advised as sap forms a natural healing barrier. BMP C102: Buffer Zones Purpose Creation of an undisturbed area or strip of natural vegetation or an established suitable planting that will provide a living filter to reduce soil erosion and runoff velocities. Conditions of Use Natural buffer zones are used along streams, wetlands and other bodies of water that need protection from erosion and sedimentation. Vegetative buffer zones can be used to protect natural swales and can be incorporated into the natural landscaping of an area. Critical -areas buffer zones should not be used as sediment treatment areas. These areas shall remain completely undisturbed. The local permitting authority may expand the buffer widths temporarily to allow the use of the expanded area for removal of sediment. Design and • Preserving natural vegetation or plantings in clumps, blocks, or strips Installation is generally the easiest and most successful method. Specifications • Leave all unstable steep slopes in natural vegetation. • Mark clearing limits and keep all equipment and construction debris out of the natural areas and buffer zones. Steel construction fencing is the most effective method in protecting sensitive areas and buffers. Alternatively, wire -backed silt fence on steel posts is marginally effective. Flagging alone is typically not effective. • Keep all excavations outside the dripline of trees and shrubs. • Do not push debris or extra soil into the buffer zone area because it will cause damage from burying and smothering. • Vegetative buffer zones for streams, lakes or other waterways shall be established by the local permitting authority or other state or federal permits or approvals. Maintenance Inspect the area frequently to make sure flagging remains in place and the Standards area remains undisturbed. Replace all damaged flagging immediately. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-5 t 1_ 1 f t 1 A BMP C103: High Visibility Fence Purpose Fencing is intended to: 1. Restrict clearing to approved limits. 2. Prevent disturbance of sensitive areas, their buffers, and other areas required to be left undisturbed. 3. Limit construction traffic to designated construction entrances, exits, or internal roads. 4. Protect areas where marking with survey tape may not provide adequate protection. Conditions of Use To establish clearing limits plastic, fabric, or metal fence may be used: • At the boundary of sensitive areas, their buffers, and other areas required to be left uncleared. • As necessary to control vehicle access to and on the site. Design and High visibility plastic fence shall be composed of a high -density Installation polyethylene material and shall be at least four feet in height. Posts for Specifications the fencing shall be steel or wood and placed every 6 feet on center (maximum) or as needed to ensure rigidity. The fencing shall be fastened to the post every six inches with a polyethylene tie. On long continuous lengths of fencing, a tension wire or rope shall be used as a top stringer to prevent sagging between posts. The fence color shall be high visibility orange. The fence tensile strength shall be 360 lbs./ft. using the ASTM D4595 testing method. If appropriate install fabric silt fence in accordance with BMP C233 to act as high visibility fence. Silt fence shall be at least 3 feet high and must be highly visible to meet the requirements of this BMP. Metal fences shall be designed and installed according to the manufacturer's specifications. Metal fences shall be at least 3 feet high and must be highly visible. Fences shall not be wired or stapled to trees. Maintenance If the fence has been damaged or visibility reduced, it shall be repaired or Standards replaced immediately and visibility restored. Volume H — Construction Stormwater Pollution Prevention - December 2014 4-6 BMP C105: Stabilized Construction Entrance / Exit Purpose Conditions of Use Stabilized Construction entrances are established to reduce the amount of sediment transported onto paved roads by vehicles or equipment. This is done by constructing a stabilized pad of quarry spalls at entrances and exits for construction sites. Construction entrances shall be stabilized wherever traffic will be entering or leaving a construction site if paved roads or other paved areas are within 1,000 feet of the site. For residential construction provide stabilized construction entrances for each residence, rather than only at the main subdivision entrance. Stabilized surfaces shall be of sufficient length/width to provide vehicle access/parking, based on lot size/configuration. On large commercial, highway, and road projects, the designer should include enough extra materials in the contract to allow for additional stabilized entrances not shown in the initial Construction SWPPP. It is difficult to determine exactly where access to these projects will take place; additional materials will enable the contractor to install them where needed. Design and See Figure 4.1.1 for details. Note: the 100' minimum length of the Installation entrance shall be reduced to the maximum practicable size when the size Specifications or configuration of the site does not allow the full length (100'). Construct stabilized construction entrances with a 12-inch thick pad of 4- inch to 8-inch quarry spalls, a 4-inch course of asphalt treated base (ATB), or use existing pavement. Do not use crushed concrete, cement, or calcium chloride for construction entrance stabilization because these products raise pH levels in stormwater and concrete discharge to surface waters of the State is prohibited. A separation geotextile shall be placed under the spalls to prevent fine sediment from pumping up into the rock pad. The geotextile shall meet the following standards: Grab Tensile Strength (ASTM D4751) 200 psi min. Grab Tensile Elongation (ASTM D4632) 30% max. Mullen Burst Strength (ASTM D3786-80a) 400 psi min. AOS (ASTM D4751) 20-45 (U.S. standard sieve size) • Consider early installation of the first lift of asphalt in areas that will paved; this can be used as a stabilized entrance. Also consider the installation of excess concrete as a stabilized entrance. During large concrete pours, excess concrete is often available for this purpose. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-7 • Fencing (see BMP C103) shall be installed as necessary to restrict traffic to the construction entrance. • Whenever possible, the entrance shall be constructed on a firm, compacted subgrade. This can substantially increase the effectiveness of the pad and reduce the need for maintenance. • Construction entrances should avoid crossing existing sidewalks and back of walk drains if at all possible. If a construction entrance must cross a sidewalk or back of walk drain, the full length of the sidewalk and back of walk drain must be covered and protected from sediment leaving the site. Maintenance Quarry spalls shall be added if the pad is no longer in accordance with Standards the specifications. • If the entrance is not preventing sediment from being tracked onto pavement, then alternative measures to keep the streets free of sediment shall be used. This may include replacement/cleaning of the existing quarry spalls, street sweeping, an increase in the dimensions of the entrance, or the installation of a wheel wash. • Any sediment that is tracked onto pavement shall be removed by shoveling or street sweeping. The sediment collected by sweeping shall be removed or stabilized on site. The pavemeni shall not be cleaned by washing down the street, except when high efficiency sweeping is ineffective and there is a threat to public safety. If it is necessary to wash the streets, the construction of a small sump to contain the wash water shall be considered. The sediment would then be washed into the sump where it can be controlled. • Perform street sweeping by hand or with a high efficiency sweeper. Do not use a non -high efficiency mechanical sweeper because this creates dust and throws soils into storm systems or conveyance ditches. • Any quarry spalls that are loosened from the pad, which end up on the roadway shall be removed immediately. • If vehicles are entering or exiting the site at points other than the construction entrance(s), fencing (see BMP C103) shall be installed to control traffic. Upon project completion and site stabilization, all construction accesses intended as permanent access for maintenance shall be permanently stabilized. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-8 Approved as Equivalent ..."10 ..,,,,,,, %I. #-*. . , • %V..' Install driveway culvert if there is a roadside ditch present 4' — 8" Quarry walls Geotexhle 17 min. thickness Driveway shall meet the requirements of the permitting agency It is recommended that the entrance be crowned so that runoff drains off the pad Provide full width of ingressiegress area Figure 4.1.1 — Stabilized Construction Entrance Ecology has approved products as able to meet the requirements of BMP C105. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology's website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html BMP C106: Wheel Wash Purpose Wheel washes reduce the amount of sediment transported onto paved roads by motor vehicles. Conditions of Use When a stabilized construction entrance (see BMP C105) is not preventing sediment from being tracked onto pavement. • Wheel washing is generally an effective BMP when installed with careful attention to topography. For example, a wheel wash can be detrimental if installed at the top of a slope abutting a right-of-way where the water from the dripping truck can run unimpeded into the street. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-9 • Pressure washing combined with an adequately sized and surfaced pad with direct drainage to a large 10-foot x 10-foot sump can be very effective. • Discharge wheel wash or tire bath wastewater to a separate on -site treatment system that prevents discharge to surface water, such as closed -loop recirculation or upland land application., or to the sanitary sewer with local sewer district approval. • Wheel wash or tire bath wastewater should not include wastewater from concrete washout areas. Design and Suggested details are shown in Figure 4.1.2. The Local Permitting Installation Authority may allow other designs. A minimum of 6 inches of asphalt Specifications treated base (ATB) over crushed base material or 8 inches over a good subgrade is recommended to pave the wheel wash. Use a low clearance truck to test the wheel wash before paving. Either a belly dump or lowboy will work well to test clearance. Keep the water level from 12 to 14 inches deep to avoid damage to truck hubs and filling the truck tongues with water. Midpoint spray nozzles are only needed in extremely muddy conditions. Wheel wash systems should be designed with a small grade change, 6- to 12-inches for a 10-foot-wide pond, to allow sediment to flow to the low side of pond to help prevent re -suspension of sediment. A drainpipe with a 2- to 3-foot riser should be installed on the low side of the pond to allow for easy cleaning and refilling. Polymers may be used to promote coagulation and flocculation in a closed -loop system. Polyacrylamide (PAM) added to the wheel wash water at a rate of 0.25 - 0.5 pounds per 1,000 gallons of water increases effectiveness and reduces cleanup time. If PAM is already being used for dust or erosion control and is being applied by a water truck, the same truck can be used to change the wash water. Maintenance Standards The wheel wash should start out the day with fresh water. The wash water should be changed a minimum of once per day. On large earthwork jobs where more than 10-20 trucks per hour are expected, the wash water will need to be changed more often. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-10 6.. SEWER PIPE WITH BUTTERFLY VALVES L 5x8. SUMP WITH OF CATCH TRA-SH PUMP wrn-i FLOATS ON SUCTION HOSE r 2.. SCHEDULE 40 1 —1 /2.. SCHEDULE 40 FOR SPRAYERS titi , D P Y NOZZ F'R 2X 5:1 :1 SLOPE PE OPE 1 t 2X SLOPE 1 Ho, SLOPE lk 15 ATB APRON TO PROTECT GROUND FROM SPLASHING WA i tit 6- SLEEVE UNDER ROAD LOCATE INVERT OF TOP PIPE 1 ABOVE BOTTOM OF WHEEL WASH frxEr SUMP 5. t DRAIN PIPE RAI I VALVES j",,s\\:‘— tr. ATB CONSTRUCTION ENTRANCE \ Lelatilatzed 18' 'SECTION A —AI ASPHALT CURB ON THE LOW ROAD SIDE TO DIRECT WATER BACK TO POND 1 :1 SLOPE NOTES: 1 . BUILD 61.3<8. SUMP TO ACCOMODATE CLEANING BY TRACKHOE. Figure 4.1.2 — Wheel Wash Notes: I. Asphalt construction entrance 6 in. asphalt treated base (ATB). 2. 3-inch trash pump with floats on the suction hose. 3. Midpoint spray nozzles, if needed. 4. 6-inch sewer pipe with butterfly valves. Bottom one is a drain. Locate top pipe's invert I foot above bottom of wheel wash. 5. 8 foot x 8 foot sump with 5 feet of catch. Build so the sump can be cleaned with a trackhoe. 6. Asphalt curb on the low road side to direct water back to pond. 7. 6-inch sleeve under road. 8. Ball valves. 9. 15 foot. ATB apron to protect ground from splashing water. Volume H — Construction Stormwater Pollution Prevention - December 2014 4-11 7 I ) BMP C107: Construction Road/Parking Area Stabilization Purpose Stabilizing subdivision roads, parking areas, and other on -site vehicle transportation routes immediately after grading reduces erosion caused by construction traffic or runoff. Conditions of Use Roads or parking areas shall be stabilized wherever they are constructed, whether permanent or temporary, for use by construction traffic. • High Visibility Fencing (see BMP C103) shall be installed, if necessary, to limit the access of vehicles to only those roads and parking areas that are stabilized. Design and • On areas that will receive asphalt as part of the project, install the first Installation lift as soon as possible. Specifications • A 6-inch depth of 2- to 4-inch crushed rock, gravel base, or crushed surfacing base course shall be applied immediately after grading or utility installation. A 4-inch course of asphalt treated base (ATB) may also be used, or the road/parking area may be paved. It may also be possible to use cement or calcium chloride for soil stabilization. If cement or cement kiln dust is used for roadbase stabilization, pH monitoring and BMPs (BMPs C252 and C253) are necessary to evaluate and minimize the effects on stormwater. If the area will not be used for permanent roads, parking areas, or structures, a 6-inch depth of hog fuel may also be used, but this is likely to require more maintenance. Whenever possible, construction roads and parking areas shall be placed on a firm, compacted subgrade. • Temporary road gradients shall not exceed 15 percent. Roadways shall be carefully graded to drain. Drainage ditches shall be provided on each side of the roadway in the case of a crowned section, or on one side in the case of a super -elevated section. Drainage ditches shall be directed to a sediment control BMP. • Rather than relying on ditches, it may also be possible to grade the road so that runoff sheet -flows into a heavily vegetated area with a well -developed topsoil. Landscaped areas are not adequate. If this area has at least 50 feet of vegetation that water can flow through, then it is generally preferable to use the vegetation to treat runoff, rather than a sediment pond or trap. The 50 feet shall not include wetlands or their buffers. If runoff is allowed to sheetflow through adjacent vegetated areas, it is vital to design the roadways and parking areas so that no concentrated runoff is created. • Storm drain inlets shall be protected to prevent sediment -laden water entering the storm drain system (see BMP C220). Maintenance Inspect stabilized areas regularly, especially after large storm events. Standards Crushed rock, gravel base, etc., shall be added as required to maintain a Volume 1 — Construction Stormwater Pollution Prevention - December 2014 4-12 t stable driving surface and to stabilize any areas that have eroded. Following construction, these areas shall be restored to pre -construction condition or better to prevent future erosion. Perform street cleaning at the end of each day or more often if necessary. BMP C120: Temporary and Permanent Seeding Purpose Conditions of Use Design and Installation Specifications Seeding reduces erosion by stabilizing exposed soils. A well -established vegetative cover is one of the most effective methods of reducing erosion. Use seeding throughout the project on disturbed areas that have reached final grade or that will remain unworked for more than 30 days. The optimum seeding windows for western Washington are April 1 through June 30 and September 1 through October 1. Between July 1 and August 30 seeding requires irrigation until 75 percent grass cover is established. Between October 1 and March 30 seeding requires a cover of mulch with straw or an erosion control blanket until 75 percent grass cover is established. Review all disturbed areas in late August to early September and complete all seeding by the end of September. Otherwise, vegetation will not establish itself enough to provide more than average protection. • Mulch is required at all times for seeding because it protects seeds from heat, moisture loss, and transport due to runoff. Mulch can be applied on top of the seed or simultaneously by hydroseeding. See BMP C121: Mulching for specifications. • Seed and mulch, all disturbed areas not otherwise vegetated at final site stabilization. Final stabilization means the completion of all soil disturbing activities at the site and the establishment of a permanent vegetative cover, or equivalent permanent stabilization measures (such as pavement, riprap, gabions, or geotextiles) which will prevent erosion. Seed retention/detention ponds as required. Install channels intended for vegetation before starting major earthwork and hydroseed with a Bonded Fiber Matrix. For vegetated channels that will have high flows, install erosion control blankets over hydroseed. Before allowing water to flow in vegetated channels, establish 75 percent vegetation cover. If vegetated channels cannot be established by seed before water flow; install sod in the channel bottom —over hydromulch and erosion control blankets. Volume II - Construction Stormwater Pollution Prevention - December 2014 4-13 • Confirm the installation of all required surface water control measures to prevent seed from washing away. • Hydroseed applications shall include a minimum of 1,500 pounds per acre of mulch with 3 percent tackifier. See BMP C121: Mulching for specifications. • Areas that will have seeding only and not landscaping may need compost or meal -based mulch included in the hydroseed in order to establish vegetation. Re -install native topsoil on the disturbed soil surface before application. • When installing seed via hydroseeding operations, only about 1/3 of the seed actually ends up in contact with the soil surface. This reduces the ability to establish a good stand of grass quickly. To overcome this, consider increasing seed quantities by up to 50 percent. • Enhance vegetation establishment by dividing the hydromulch operation into two phases: 1. Phase 1- Install all seed and fertilizer with 25-30 percent mulch and tackifier onto soil in the first lift. 2. Phase 2- Install the rest of the mulch and tackifier over the first lift. Or, enhance vegetation by: 1. Installing the mulch, seed, fertilizer, and tackifier in one lift. 2. Spread or blow straw over the top of the hydromulch at a rate of 800-1000 pounds per acre. 3. Hold straw in place with a standard tackifier. Both of these approaches will increase cost moderately but will greatly improve and enhance vegetative establishment. The increased cost may be offset by the reduced need for: • Irrigation. • Reapplication of mulch. • Repair of failed slope surfaces. This technique works with standard hydromulch (1,500 pounds per acre minimum) and BFM/MBFMs (3,000 pounds per acre minimum). • Seed may be installed by hand if: • Temporary and covered by straw, mulch, or topsoil. • Permanent in small areas (usually less than 1 acre) and covered with mulch, topsoil, or erosion blankets. • The seed mixes listed in the tables below include recommended mixes for both temporary and permanent seeding. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-14 • Apply these mixes, with the exception of the wetland mix, at a rate of 120 pounds per acre. This rate can be reduced if soil amendments or slow -release fertilizers are used. • Consult the local suppliers or the local conservation district for their recommendations because the appropriate mix depends on a variety of factors, including location, exposure, soil type, slope, and expected foot traffic. Alternative seed mixes approved by the local authority may be used. • Other mixes may be appropriate, depending on the soil type and hydrology of the area. Table 4.1.2 lists the standard mix for areas requiring a temporary vegetative cover. Table 4.1.2 Temporary Erosion Control Seed Mix % Weight % Purity % Germination Chewings or annual blue grass Festuca rubra var. commutata or Poa anna 40 98 90 Perennial rye - Lolium perenne 50 98 90 Redtop or colonial bentgrass Agrostis alba or Agrostis tenuis 5 92 85 White dutch clover Trifolium repens 5 98 90 • Table 4.1.3 lists a recommended mix for landscaping seed. Table 4.1.3 Landscaping Seed Mix % Weight % Purity % Germination Perennial rye blend Lolium perenne 70 98 90 Chewings and red fescue blend Festuca rubra var. commutata or Festuca rubra 30 98 90 Volume II — Construction Stormwater Pollution Prevention - December 2014 4-15 A r 1 .._ A r a • Table 4.1.4 lists a turf seed mix for dry situations where there is no need for watering. This mix requires very little maintenance. Table 4.1.4 Low -Growing Turf Seed Mix % Weight % Purity % Germination D a a fescue (several varieties) Festuca arundinacea var. 45 98 90 Dwarfperennial rye (Barclay) Lolium perenne var. barclay 30 98 90 Red fescue Festuca rubra 20 98 90 Colonial bentgrass Agrostis tenuis 5 98 90 • Table 4.1.5 lists a mix for bioswales and other intermittently wet areas. Table 4.1.5 Bioswale Seed Mix* % Weight % Purity % Germination Tall or meadow fescue Festuca arundinacea or Festuca elatior 75-80 98 90 Seaside/Creeping bentgrass Agrostis palustris 10- 5 92 85 Redtop bentgrass Agrostis alba or Agrostis gigantea 5-10 90 80 * Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix Volume II — Construction Stormwater Pollution Prevention - December 2014 4-16 • Table 4.1.6 lists a low -growing, relatively non-invasive seed mix appropriate for very wet areas that are not regulated wetlands. Apply this mixture at a rate of 60 pounds per acre. Consult Hydraulic Permit Authority (HPA) for seed mixes if applicable. Table 4.1.6 Wet Area Seed Mix* % Weight % Purity % Germination Tall or meadow fescue Festuca arundinacea or Festuca elatior 60-70 98 90 Seaside/Creeping bentgrass Agrostis palustris 10-15 98 85 Meadow foxtail Alepocurus pratensis 10-15 90 80 Alsike clover Trifolium hybridum 1-6 98 90 Redtop bentgrass Agrostis alba 1-6 92 85 * Modified Briargreen, Inc. Hydroseeding Guide Wetlands Seed Mix • Table 4.1.7 lists a recommended meadow seed mix for infrequently maintained areas or non -maintained areas where colonization by native plants is desirable. Likely applications include rural road and utility right-of-way. Seeding should take place in September or very early October in order to obtain adequate establishment prior to the winter months. Consider the appropriateness of clover, a fairly invasive species, in the mix. Amending the soil can reduce the need for clover. Table 4.1.7 Meadow Seed Mix eight% Purity % Germination Redtop or Oregon bentgrass 20 92 85 Agrostis alba or Agrostis oregonensis Red fescue 70 98 90 Festuca rubra hite dutch clover 10 98 90 Trifolium repens Volume H — Construction Stormwater Pollution Prevention - December 2014 4-1 7 f f, Roughening and Rototilling: • The seedbed should be firm and rough. Roughen all soil no matter what the slope. Track walk slopes before seeding if engineering purposes require compaction. Backblading or smoothing of slopes greater than 4H:1V is not allowed if they are to be seeded. • Restoration -based landscape practices require deeper incorporation than that provided by a simple single -pass rototilling treatment. Wherever practical, initially rip the subgrade to improve long-term permeability, infiltration, and water inflow qualities. At a minimum, permanent areas shall use soil amendments to achieve organic matter and permeability performance defined in engineered soil/landscape systems. For systems that are deeper than 8 inches complete the rototilling process in multiple lifts, or prepare the engineered soil system per specifications and place to achieve the specified depth. • Fertilizers: • Conducting soil tests to determine the exact type and quantity of fertilizer is recommended. This will prevent the over -application of fertilizer. • Organic matter is the most appropriate form of fertilizer because it provides nutrients (including nitrogen, phosphorus, and potassium) in the least water-soluble form. • In general, use 10-4-6 N-P-K (nitrogen -phosphorus -potassium) fertilizer at a rate of 90 pounds per acre. Always use slow -release fertilizers because they are more efficient and have fewer environmental impacts. Do not add fertilizer to the hydromulch machine, or agitate, more than 20 minutes before use. Too much agitation destroys the slow -release coating. • There are numerous products available that take the place of chemical fertilizers. These include several with seaweed extracts that are beneficial to soil microbes and organisms. If 100 percent cottonseed meal is used as the mulch in hydroseed, chemical fertilizer may not be necessary. Cottonseed meal provides a good source of long-term, slow -release, available nitrogen. • Bonded Fiber Matrix and Mechanically Bonded Fiber Matrix: • On steep slopes use Bonded Fiber Matrix (BFM) or Mechanically Bonded Fiber Matrix (MBFM) products. Apply BFM/MBFM products at a minimum rate of 3,000 pounds per acre of mulch with approximately 10 percent tackifier. Achieve a minimum of 95 percent soil coverage during application. Numerous products are available commercially. Installed products per manufacturer's instructions. Most products require 24-36 hours to cure before rainfall and cannot be installed on wet or saturated soils. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-18 Generally, products come in 40-50 pound bags and include all necessary ingredients except for seed and fertilizer. • BFMs and MBFMs provide good alternatives to blankets in most areas requiring vegetation establishment. Advantages over blankets include: • BFM and MBFMs do not require surface preparation. • Helicopters can assist in installing BFM and MBFMs in remote areas. • On slopes steeper than 2.5H:1V, blanket installers may require ropes and harnesses for safety. • Installing BFM and MBFMs can save at least $1,000 per acre compared to blankets. Maintenance Reseed any seeded areas that fail to establish at least 80 percent cover Standards (100 percent cover for areas that receive sheet or concentrated flows). If reseeding is ineffective, use an alternate method such as sodding, mulching, or nets/blankets. If winter weather prevents adequate grass growth, this time limit may be relaxed at the discretion of the local authority when sensitive areas would otherwise be protected. • Reseed and protect by mulch any areas that experience erosion after achieving adequate cover. Reseed and protect by mulch any eroded area. Supply seeded areas with adequate moisture, but do not water to the extent that it causes runoff. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C120. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology's website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html. BMP C121: Mulching Purpose Mulching soils provides immediate temporary protection from erosion. Mulch also enhances plant establishment by conserving moisture, holding fertilizer, seed, and topsoil in place, and moderating soil temperatures. There is an enormous variety of mulches that can be used. This section discusses only the most common types of mulch. Conditions of Use As a temporary cover measure, mulch should be used: • For less than 30 days on disturbed areas that require cover. • At all times for seeded areas, especially during the wet season and during the hot summer months. Volume II - Construction Stormwater Pollution Prevention - December 2014 4-19 r a a- I I During the wet season on slopes steeper than 3H:1V with more than 10 feet of vertical relief. Mulch may be applied at any time of the year and must be refreshed periodically. For seeded areas mulch may be made up of 100 percent: cottonseed meal; fibers made of wood, recycled cellulose, hemp, kenaf; compost; or blends of these. Tackifier shall be plant -based, such as guar or alpha plantago, or chemical -based such as polyacrylamide or polymers. Any mulch or tackifier product used shall be installed per manufacturer's instructions. Generally, mulches come in 40-50 pound bags. Seed and fertilizer are added at time of application. Design and For mulch materials, application rates, and specifications, see Table 4.1.8. Installation Always use a 2-inch minimum mulch thickness; increase the thickness Specifications until the ground is 95% covered (i.e. not visible under the mulch layer). Note: Thickness may be increased for disturbed areas in or near sensitive areas or other areas highly susceptible to erosion. Where the option of "Compost" is selected, it should be a coarse compost that meets the following size gradations when tested in accordance with the U.S. Composting Council "Test Methods for the Examination of Compost and Composting" (TMECC) Test Method 02.02-B. Coarse Compost Minimum Percent passing 3" sieve openings 100% Minimum Percent passing 1" sieve openings 90% Minimum Percent passing 3/4" sieve openings 70% Minimum Percent passing 1/4" sieve openings 40% Mulch used within the ordinary high-water mark of surface waters should be selected to minimize potential flotation of organic matter. Composted organic materials have higher specific gravities (densities) than straw, wood, or chipped material. Consult Hydraulic Permit Authority (HPA) for mulch mixes if applicable. Maintenance Standards • The thickness of the cover must be maintained. • Any areas that experience erosion shall be remulched and/or protected with a net or blanket. If the erosion problem is drainage related, then the problem shall be fixed and the eroded area remulched. Volume I — Construction Stormwater Pollution Prevention - December 2014 4-20 Table 4.1.8 Mulch Standards and Guidelines Mulch Material Quality Standards Application Rates Remarks Straw Air-dried; free from undesirable seed and coarse material. 2"-3" thick; 5 bales per 1,000 sf or 2-3 tons per acre Cost-effective protection when applied with adequate thickness. Hand -application generally requires greater thickness than blown straw. The thickness of straw may be reduced by half when used in conjunction with seeding. In windy areas straw must be held in place by crimping, using a tackifier, or covering with netting. Blown straw always has to be held in place with a tackifier as even light winds will blow it away. Straw, however, has several deficiencies that should be considered when selecting mulch materials. It often introduces and/or encourages the propagation of weed species and it has no significant long- term benefits. It should also not be used within the ordinary high-water elevation of surface waters (due to flotation). Hydromulch No growth inhibiting factors. Approx. 25-30 lbs per 1,000 sf or 1,500 - 2.000 lbs per acre Shall be applied with hydromulcher. Shall not he used without seed and tackifier unless the application rate is at least doubled. Fibers longer than about %-1 inch clog hydromulch equipment. Fibers should be kept to less than % inch, Compost No visible water or dust during handling. Must be produced per WAC 2" thick min,; approx. 100 tons per acre (approx. 800 lbs per yard) More effective control can be obtained by increasing thickness to 3". Excellent mulch for protecting final grades until landscaping because it can be directly seeded or tilled into soil as an amendment. Compost used for mulch has a coarser size gradation than compost used for BMP C125 or BMP T5.13 (see Chapter 5 of Volume V of this manual) It is more stable and practical to use in wet areas and during rainy weather conditions. Do not use near wetlands or near phosphorous impaired water bodies. 173-350, Solid Waste Handling Standards, but may have up to 3 5 % biosolids. Chipped Site Vegetation Average size shall be several inches. Gradations from tines to 6 inches in length for texture, variation, and interlocking properties. 2" thick min.; This is a cost-etTective way to dispose of debris from clearing and grubbing, and it eliminates the problems associated with burning. Generally, it should not be used on slopes above approx. 10% because of its tendency to be transported by runoff It is not recommended within 200 feet of surface waters. If seeding is expected shortly after mulch, the decomposition of the chipped vegetation may tie up nutrients important to grass establishment. Wood -based Mulch or Wood Straw No visible water or dust during handling. Must be purchased from a supplier with a Solid Waste Handling Permit or one exempt from solid waste regulations. 2" thick min.; approx. 100 tons per acre (approx. 800 lbs. per cubic yard) This material is often called "hog or hogged fuel." The use of mulch ultimately improves the organic matter in the soil. Special caution is advised regarding the source and composition of wood -based mulches. Its preparation typically does not provide any weed seed control, so evidence of residual vegetation in its composition or known inclusion of weed plants or seeds should be monitored and prevented (or minimized). Wood Strand Mulch A blend of loose, long, thin wood pieces derived from native conifer or deciduous trees with high length -to -width ratio. 2" thick min. Cost-effective protection when applied with adequate thickness. A minimum of 95-percent of the wood strand shall have lengths between 2 and 10-inches, with a width and thickness between 1/16 and %-inches. The mulch shall not contain resin, tannin, or other compounds in quantities that would be detrimental to plant life. Sawdust or wood shavings shall not be used as mulch. (WSDOT specification (9-14.4(4)) Volume II —Construction Stormwater Pollution Prevention - December 2014 4-21 BMP C123: Plastic Covering Purpose Plastic covering provides immediate, short-term erosion protection to slopes and disturbed areas. Conditions of Plastic covering may be used on disturbed areas that require cover Use measures for less than 30 days, except as stated below. • Plastic is particularly useful for protecting cut and fill slopes and stockpiles. Note: The relatively rapid breakdown of most polyethylene sheeting makes it unsuitable for long-term (greater than six months) applications. • Due to rapid runoff caused by plastic covering, do not use this method upslope of areas that might be adversely impacted by concentrated runoff. Such areas include steep and/or unstable slopes. .• Plastic sheeting may result in increased runoff volumes and velocities, requiring additional on -site measures to counteract the increases. Creating a trough with wattles or other material can convey clean water away from these areas. • To prevent undercutting, trench and backfill rolled plastic covering • products. • While plastic is inexpensive to purchase, the added cost of installation, maintenance, removal, and disposal make this an expensive material, up to $1.50-2.00 per square yard. • Whenever plastic is used to protect slopes install water collection r measures at the base of the slope. These measures include plastic - covered berms, channels, and pipes used to covey clean rainwater away from bare soil and disturbed areas. Do not mix clean runoff from : a plastic covered slope with dirty runoff from a project. • Other uses for plastic include: r • 1. Temporary ditch liner. 2. Pond liner in temporary sediment pond. r 3. Liner for bermed temporary fuel storage area if plastic is not reactive to the type of fuel being stored. 4. Emergency slope protection during heavy rains. - -7 5. Temporary drainpipe ("elephant trunk") used to direct water. • Design and e Plastic slope cover must be installed as follows: f 7' Installation 1. Run plastic up and down slope, not across slope. Specifications t 2. Plastic may be installed perpendicular to a slope if the slope length is less than 10 feet. • 3 . Minimum of 8-inch overlap at seams. Volume II— Construction Stormwater Pollution Prevention - December 2014 4-26 4. On long or wide slopes, or slopes subject to wind, tape all seams. 5. Place plastic into a small (12-inch wide by 6-inch deep) slot trench at the top of the slope and backfill with soil to keep water from flowing underneath. 6. Place sand filled burlap or geotextile bags every 3 to 6 feet along seams and tie them together with twine to hold them in place. 7. Inspect plastic for rips, tears, and open seams regularly and repair immediately. This prevents high velocity runoff from contacting bare soil which causes extreme erosion. 8. Sandbags may be lowered into place tied to ropes. However, all sandbags must be staked in place. • Plastic sheeting shall have a minimum thickness of 0.06 millimeters. • If erosion at the toe of a slope is likely, a gravel berm, riprap, or other suitable protection shall be installed at the toe of the slope in order to reduce the velocity of runoff. Maintenance • Torn sheets must be replaced and open seams repaired. Standards • Completely remove and replace the plastic if it begins to deteriorate due to ultraviolet radiation. • Completely remove plastic when no longer needed. • Dispose of old tires used to weight down plastic sheeting appropriately. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C 123. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology's website at http://www.ecy.wa.gov/programs/wq/stormwater/new-tech/equivalent.html BMP C124: Sodding Purpose The purpose of sodding is to establish permanent turf for immediate erosion protection and to stabilize drainage ways where concentrated overland flow will occur. Conditions of Use Sodding may be used in the following areas: • Disturbed areas that require short-term or long-term cover. • Disturbed areas that require immediate vegetative cover. • All waterways that require vegetative lining. Waterways may also be seeded rather than sodded, and protected with a net or blanket. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-27 7 1 _ r r f r ▪ • • 1 drinking water treatment, will be used for soil applications. Recent media attention and high interest in PAM has resulted in some entrepreneurial exploitation of the term "polymer." All PAM are polymers, but not all polymers are PAM, and not all PAM products comply with ANSI/NSF Standard 60. PAM use shall be reviewed and approved by the local permitting authority. • PAM designated for these uses should be "water soluble" or "linear" or "non-crosslinked". Cross -linked or water absorbent PAM, polymerized in highly acidic (pH<2) conditions, are used to maintain soil moisture content. • The PAM anionic charge density may vary from 2-30 percent; a value of 18 percent is typical. Studies conducted by the United States Department of Agriculture (USDA)/ARS demonstrated that soil stabilization was optimized by using very high molecular weight (12- 15 mg/mole), highly anionic (>20% hydrolysis) PAM. • PAM tackifiers are available and being used in place of guar and alpha plantago. Typically, PAM tackifiers should be used at a rate of no more than 0.5-1 Ib. per 1000 gallons of water in a hydromulch machine. Some tackifier product instructions say to use at a rate of 3 —5 lbs. per acre, which can be too much. In addition, pump problems can occur at higher rates due to increased viscosity. Maintenance • PAM may be reapplied on actively worked areas after a 48-hour Standards period. • Reapplication is not required unless PAM treated soil is disturbed or unless turbidity levels show the need for an additional application. If PAM treated soil is left undisturbed a reapplication may be necessary after two months. More PAM applications may be required for steep slopes, silty and clayey soils (USDA Classification Type "C" and "D" soils), long grades, and high precipitation areas. When PAM is applied first to bare soil and then covered with straw, a reapplication may not be necessary for several months. • Loss of sediment and PAM may be a basis for penalties per RCW 90.48.080. BMP C130: Surface Roughening Purpose Surface roughening aids in the establishment of vegetative cover, reduces runoff velocity, increases infiltration, and provides for sediment trapping through the provision of a rough soil surface. Horizontal depressions are created by operating a tiller or other suitable equipment on the contour or by leaving slopes in a roughened condition by not fine grading them. Use this BMP in conjunction with other BMPs such as seeding, mulching, or sodding. Volume II - Construction Stormwater Pollution Prevention - December 2014 4-35 Conditions for • All slopes steeper than 3H:IV and greater than 5 vertical feet Use require surface roughening to a depth of 2 to 4 inches prior to seeding.. • Areas that will not be stabilized immediately may be roughened to reduce runoff velocity until seeding takes place. • Slopes with a stable rock face do not require roughening. • Slopes where mowing is planned should not be excessively roughened. Design and There are different methods for achieving a roughened soil surface on a Installation slope, and the selection of an appropriate method depends upon the type of Specifications slope. Roughening methods include stair -step grading, grooving, contour furrows, and tracking. See Figure 4.1.5 for tracking and contour furrows. Factors to be considered in choosing a method are slope steepness, mowing requirements, and whether the slope is formed by cutting or filling. • Disturbed areas that will not require mowing may be stair -step graded, grooved, or left rough after filling. • Stair -step grading is particularly appropriate in soils containing large amounts of soft rock. Each "step" catches material that sloughs from above, and provides a level site where vegetation can become established. Stairs should be wide enough to work with standard earth moving equipment. Stair steps must be on contour or gullies will form on the slope. • Areas that will be mowed (these areas should have slopes less steep than 3H:I V) may have small furrows left by disking, harrowing, raking, or seed -planting machinery operated on the contour. • Graded areas with slopes steeper than 3H:1 V but less than 2H:1V should be roughened before seeding. This can be accomplished in a variety of ways, including "track walking," or driving a crawler tractor up and down the slope, leaving a pattern of cleat imprints parallel to slope contours. • Tracking is done by operating equipment up and down the slope to leave horizontal depressions in the soil. Maintenance • Areas that are graded in this manner should be seeded as quickly as Standards possible. • Regular inspections should be made of the area. If rills appear, they should be re -graded and re -seeded immediately. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-36 r r 1 ' 7 k Tracking 'TRACKINGwith machinery up and down the slope provides grooves that will catch seed, rainfall and reduce runoff. Contour Furrows 50' (15m) Grooves Will Catch Seed, Fertilizer, Mulch, Rainfall and Decrease Runoff. • • 6" min (150mm) Figure 4.1.5 — Surface Roughening by Tracking and Contour Furrows Volume II — Construction Stormwater Pollution Prevention - December 2014 4-37 BMP C250: Construction Stormwater Chemical Treatment BMP C251: Construction Stormwater Filtration BMP C252: High pH Neutralization Using CO2 BMP C253: pH Control for High pH Water BMP C200: Interceptor Dike and Swale Purpose Conditions of Use Provide a ridge of compacted soil, or a ridge with an upslope swale, at the top or base of a disturbed slope or along the perimeter of a disturbed construction area to convey stormwater. Use the dike and/or swale to intercept the runoff from unprotected areas and direct it to areas where erosion can be controlled. This can prevent storm runoff from entering the work area or sediment -laden runoff from leaving the construction site. Where the runoff from an exposed site or disturbed slope must be conveyed to an erosion control facility which can safely convey the stormwater. Locate upslope of a construction site to prevent runoff from entering disturbed area. • When placed horizontally across a disturbed slope, it reduces the amount and velocity of runoff flowing down the slope. • Locate downslope to collect runoff from a disturbed area and direct water to a sediment basin. Design and • Dike and/or swale and channel must be stabilized with temporary or Installation permanent vegetation or other channel protection during construction. Specifications • Channel requires a positive grade for drainage; steeper grades require channel protection and check dams. • Review construction for areas where overtopping may occur. • Can be used at top of new fill before vegetation is established. • May be used as a permanent diversion channel to carry the runoff. • Sub -basin tributary area should be one acre or less. • Design capacity for the peak volumetric flow rate calculated using a 10-minute time step from a 10-year, 24-hour storm, assuming a Type IA rainfall distribution, for temporary facilities. Alternatively, use 1.6 times the 10-year, I -hour flow indicated by an approved continuous runoff model. For facilities that will also serve on a permanent basis, consult the local government's drainage requirements. Volume II - Construction Stormwater Pollution Prevention - December 2014 4-57 Interceptor dikes shall meet the following criteria: Top Width 2 feet minimum. Height 1.5 feet minimum on berm. Side Slope 2H:1V or flatter. Grade Depends on topography, however, dike system minimum is 0.5%, and maximum is 1%. Compaction Minimum of 90 percent ASTM D698 standard proctor. Horizontal Spacing of Interceptor Dikes: - 4 Average Slope Slope Percent Flowpath Length 20H: 1 V or less 3-5% 300 feet (10 to 20)H:1V 5-10% 200 feet (4 to 10)H:1'V I0-25% 100 feet (2 to 4)H:1V 25-50% 50 feet Stabilization depends on velocity and reach Slopes <5% Seed and mulch applied within 5 days of dike construction (see BMP C121, Mulchino). Slopes 5 - 40% Dependent on runoff velocities and dike materials. Stabilization should be done immediately using either sod or riprap or other measures to avoid erosion. • The upslope side of the dike shall provide positive drainage to the dike outlet. No erosion shall occur at the outlet. Provide energy dissipation measures as necessary. Sediment -laden runoff must be released through a sediment trapping facility. • Minimize construction traffic over temporary dikes. Use temporary cross culverts for channel crossing. Interceptor swales shall meet the following criteria: Bottom Width 2 feet minimum; the cross-section bottom shall be level. Depth 1-foot minimum. Side Slope 2H:1V or flatter. Grade Maximum 5 percent, with positive drainage to a suitable outlet (such as a sediment pond). Stabilization Seed as per BMP C120, Temporary and Permanent Seeding, or BMP C202, Channel Lining, 12 inches thick riprap pressed into the bank and extending at least 8 inches vertical from the bottom. Inspect diversion dikes and interceptor swales once a week and after every rainfall. Immediately remove sediment from the flow area. Volume H - Construction Stormwater Pollution Prevention - December 2014 4-58 Spreader must be level 6" min. 1 Treated 2"x10" may be abutted end to end for max. spreader length of 50' 6" min. 1" min. -=-1 1-- I I I I I I I I I 1: I 1111 II I —I I I_ I I I III II 18" min. rebar supports 8' max. spacing Figure 4.2.6 — Detail of Level Spreader BMP C207: Check Dams Purpose Conditions of Use Construction of small dams across a swale or ditch reduces the velocity of concentrated flow and dissipates energy at the check dam. Where temporary channels or permanent channels are not yet vegetated, channel lining is infeasible, and/or velocity checks are required. • Check dams may not be placed in streams unless approved by the State Department of Fish and Wildlife. Check dams may not be placed in wetlands without approval from a permitting agency. • Do not place check dams below the expected backwater from any salmonid bearing water between October 1 and May 31 to ensure that there is no loss of high flow refuge habitat for overwintering juvenile salmonids and emergent salmonid fry. • Construct rock check dams from appropriately sized rock. The rock used must be large enough to stay in place given the expected design flow through the channel. The rock must be placed by hand or by mechanical means (no dumping of rock to form dam) to achieve complete coverage of the ditch or swale and to ensure that the center of the dam is lower than the edges. • Check dams may also be constructed of either rock or pea -gravel filled bags. Numerous new products are also available for this purpose. They tend to be re -usable, quick and easy to install, effective, and cost efficient. • Place check dams perpendicular to the flow of water. • The dam should form a triangle when viewed from the side. This prevents undercutting as water flows over the face of the dam rather than falling directly onto the ditch bottom. Volume — Construction Stormwater Pollution Prevention - December 2014 4-74 • Before installing check dams impound and bypass upstream water flow away from the work area. Options for bypassing include pumps, siphons, or temporary channels. • Check dams in association with sumps work more effectively at slowing flow and retaining sediment than just a check dam alone. A deep sump should be provided immediately upstream of the check dam. • In some cases, if carefully located and designed, check dams can remain as permanent installations with very minor regrading. They may be left as either spillways, in which case accumulated sediment would be graded and seeded, or as check dams to prevent further sediment from leaving the site. • The maximum spacing between the dams shall be such that the toe of the upstream dam is at the same elevation as the top of the downstream dam. • Keep the maximum height at 2 feet at the center of the dam. • Keep the center of the check dam at least 12 inches lower than the outer edges at natural ground elevation. • Keep the side slopes of the check clam at 2H:1 V or flatter. • Key the stone into the ditch banks and extend it beyond the abutments a minimum of 18 inches to avoid washouts from overflow around the dam. • Use filter fabric foundation under a rock or sand bag check dam. If a blanket ditch liner is used, filter fabric is not necessary. A piece of organic or synthetic blanket cut to fit will also work for this purpose. • In the case of grass -lined ditches and swales, all check dams and accumulated sediment shall be removed when the grass has matured sufficiently to protect the ditch or swale - unless the slope of the swale is greater than 4 percent. The area beneath the check dams shall be seeded and mulched immediately after dam removal. • Ensure that channel appurtenances, such as culvert entrances below check dams, are not subject to damage or blockage from displaced stones. Figure 4.2.7 depicts a typical rock check dam. Maintenance Check dams shall be monitored for performance and sediment Standards accumulation during and after each runoff producing rainfall. Sediment shall be removed when it reaches one half the sump depth. • Anticipate submergence and deposition above the check dam and erosion from high flows around the edges of the dam. • If significant erosion occurs between dams, install a protective riprap liner in that portion of the channel. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-75 Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C207. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology's website at http://www.ecy.wa.gov/programs/wq/stormwater/newtech/equivalent.html Volume II — Construction Stormwater Pollution Prevention - December 2014 4-76 r I r r r 1 View Looking Upstream ,11 NOTE: Key stone into channel banks and extend it beyond the abutments a minimum of 18" (0.5m) to prevent flow around dam. Section A - A FLOW 4 24" (0.6m) 18" (0.5m) 12" (150mm) 8' (2.4m) Spacing Between Check Dams "L' = the distance such that points 'A' arid 'EV are of equal elevation. POINT 'A' 24" (0.6m) POINT 'B' NOT TO SCALE Figure 4.2.7 — Rock Check Dam Volume II — Construction Stormwater Pollution Prevention - December 2014 4-77 BMP C209: Outlet Protection Purpose Outlet protection prevents scour at conveyance outlets and minimizes the potential for downstream erosion by reducing the velocity of concentrated stormwater flows. Conditions ofuse Outlet protection is required at the outlets of all ponds, pipes, ditches, or other conveyances, and where runoff is conveyed to a natural or manmade drainage feature such as a stream, wetland, lake, or ditch. Design and Installation Specifications The receiving channel at the outlet of a culvert shall be protected from erosion by rock lining a minimum of 6 feet downstream and extending up the channel sides a minimum of 1—foot above the maximum tailwater elevation or 1-foot above the crown, whichever is higher. For large pipes (more than 18 inches in diameter), the outlet protection lining of the channel is lengthened to four times the diameter of the culvert. • Standard wingwalls, and tapered outlets and paved channels should also be considered when appropriate for permanent culvert outlet protection. (See WSDOT Hydraulic Manual, available through WSDOT Engineering Publications). • Organic or synthetic erosion blankets, with or without vegetation, are usually more effective than rock, cheaper, and easier to install. Materials can be chosen using manufacturer product specifications. ASTM test results are available for most products and the designer can choose the correct material for the expected flow. • With low flows, vegetation (including sod) can be effective. • The following guidelines shall be used for riprap outlet protection: 1. If the discharge velocity at the outlet is less than 5 fps (pipe slope less than 1 percent), use 2-inch to 8-inch riprap. Minimum thickness is 1-foot. 2. For 5 to 10 fps discharge velocity at the outlet (pipe slope less than 3 percent), use 24-inch to 4-foot riprap. Minimum thickness is 2 feet. 3. For outlets at the base of steep slope pipes (pipe slope greater than 10 percent), an engineered energy dissipater shall be used. • Filter fabric or erosion control blankets should always be used under riprap to prevent scour and channel erosion. • New pipe outfalls can provide an opportunity for low-cost fish habitat improvements. For example, an alcove of low -velocity water can be created by constructing the pipe outfall and associated energy dissipater back from the stream edge and digging a channel, over - widened to the upstream side, from the outfall. Overwintering juvenile and migrating adult salmonids may use the alcove as shelter during 4-80 Volume — Construction Stormwater Pollution Prevention February 2005 Maintenance Standards high flows. Bank stabilization, bioengineering, and habitat features may be required for disturbed areas. See Volume V for more information on outfall system design. • Inspect and repair as needed. • Add rock as needed to maintain the intended function. • Clean energy dissipater if sediment builds up. February 2005 Volume II — Construction Stormwater Pollution Prevention 4-81 • New pipe outfalls can provide an opportunity for low-cost fish habitat improvements. For example, an alcove of low-velocgty water can be created by constructing the pipe outfall and associated energy dissipater back from the stream edge and digging a channel, over - widened to the upstream side, from the outfall. Overwintering juvenile and migrating adult salmonids may use the alcove as shelter during high flows. Bank stabilization, bioengineering, and habitat features may be required for disturbed areas. This work may require a HPA. See Volume V for more information on outfall system design. Maintenance • Inspect and repair as needed. Standards Add rock as needed to maintain the intended function. Clean energy dissipater if sediment builds up. BMP C220: Storm Dram Inlet Protection Purpose Conditions of Use Storm drain inlet protection prevents coarse sediment from entering drainage systems prior to permanent stabilization of the disturbed area. Use storm drain inlet protection at inlets that are operational before permanent stabilization of the disturbed drainage area. Provide protection for all storm drain inlets downslope and within 500 feet of a disturbed or construction area, unless conveying runoff entering catch basins to a sediment pond or trap. Also consider inlet protection for lawn and yard drains on new home construction. These small and numerous drains coupled with lack of gutters in new home construction can add significant amounts of sediment into the roof drain system. If possible delay installing lawn and yard drains until just before landscaping or cap these drains to prevent sediment from entering the system until completion of landscaping. Provide 18-inches of sod around each finished lawn and yard drain. Table 4.2.2 lists several options for inlet protection. All of the methods for storm drain inlet protection tend to plug and require a hiigh frequency of maintenance. Limit drainage areas to one acre or less. Possibly provide emergency overflows with additional end -of -pipe treatment where stormwater ponding would cause a hazard. Volume H — Construction Stormwater Pollution Prevention - December 2014 4-80 / ^ r ^ � _- i '` . -' r*1 ' , ... 7 ', -' -' ' ` ^' r� -' � ° k�' Table 4.2.2 Storm Drain Inlet Protection ^ Type wfInlet Emergency Protection Overflow Applicable for Pavmd/Earthen Surfaces Conditions ofUse Drop Inlet Protection Excavated drop inlet Ymm, prot ection temporary flooding will occur Earthen App|iuob|afovheavy flmwo.Easy tomaintain. Large area Requirement: 30' X 307nore Block and gravel drop Yes inlet protection Paved or Earthen App|immb>ofor heavy concentrated flaws. Will not pond. Gravel and wire drop No inlet protection App|ioeb|ehxheavy concentrated flows. Will pond. Can withstand traffic. Catch basin filters Yes Paved or Earthen Frequent maintenance required. Curb Inlet Protection Curb inlet protection Small capacity with mvvomdem weir ovarf|mw Paved Uoodfor mturdy.mnrecmmpact installation. 8|mdk and gravel curb Yes inlet protection Paved Sturdy. but limited filtration. Culvert Inlet Protection Culvert inlet sediment trap 18month expected life. Design and Excavated Drop Inlet Protection '/\oexcavated impoundment around the Installation uUnnn drain. Sediment settles out ofthe otonnp/mter prior to entering the Specifications storm drain. � Provide udepth of 1-2 ftao measured from the crest of the inlet structure. ° Slope sides u[excavation nosteeper than 2{f:IV. ° Minimum volume ofexcavation 35cubic Yards. ° Shape basin to fit site with longest dimension oriented toward the longest inflow area. ° loxta|| provisions for draining to prevent standing water problems. ° Clear the area of all debris. • Grade the approach to the in)etunifoom|y. ° Drill weep holes into the side of the inlet. ° Protect weep holes with screen wire and washed aggregate. ° Sea] weep holes when removing structure and stabilizing area. Volume D-Construction Stormwuter Pollution Prevention ' December 2014 • Build a temporary dike, if necessary, to the down slope side of the structure to prevent bypass flow. Black and Gravel Filter - A barrier formed around the storm drain inlet with standard concrete blocks and gravel. See Figure 4.2.8. • Provide a height of 1 to 2 feet above inlet. • Recess the first row 2-inches into the ground for stability. • Support subsequent courses by placing a 2x4 through the block opening. • Do not use mortar. • Lay some blocks in the bottom row on their side for dewatering the pool. • Place hardware cloth or comparable wire mesh with Y2-inch openings over all block openings. • Place gravel just below the top of blocks on slopes of 2H:1V or flatter. • An alternative design is a gravel donut. • Provide an inlet slope of 3H:1V. • Provide an outlet slope of 2H:IV. • Provide al -foot wide level stone area between the structure and the inlet. • Use inlet slope stones 3 inches in diameter or larger. • Use gravel 1/2- to 3/4-inch at a minimum thickness of 1-foot for the outlet slope. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-82 r • •-• Plan View Drain _ Grate Section A - A —A 1 Concrete Block Gravel Backfill Overflow — Water Water Drop Inlet Concrete Block Gravel Backfill Wire Screen or Filter Fabric Ponding Height Notes: 1. Drop inlet sediment barriers are to be used for small, nearly level drainage areas. (less than 5%) 2. Excavate a basin of sufficient size adjacent to the drop inlet. 3. The top of the structure (ponding height) must be well below the ground elevation downslope to prevent runoff from bypassing the inlet. A temporary dike may be necessary on the downslope side of the structure. Figure 4.2.8 — Block and Gravel Filter Gravel and Wire Mesh Filter - A gravel barrier placed over the top of the inlet. This structure does not provide an overflow. • Use a hardware cloth or comparable wire mesh with 1/4-inch openings. • Use coarse aggregate. • Provide a height 1-foot or more, 18-inches wider than inlet on all sides. • Place wire mesh over the drop inlet so that the wire extends a minimum of 1-foot beyond each side of the inlet structure. • Overlap the strips if more than one strip of mesh is necessary. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-83 • Place coarse aggregate over the wire mesh. • Provide at least a 12-inch depth of gravel over the entire inlet opening and extend at least I 8-inches on all sides. Catchbasin Filters — Use inserts designed by manufacturers for construction sites. The limited sediment storage capacity increases the amount of inspection and maintenance required, which may be daily for heavy sediment loads. To reduce maintenance requirements combine a catchbasin filter with another type of inlet protection. This type of inlet protection provides flow bypass without overflow and therefore may be a better method for inlets located along active rights -of -way. • Provides 5 cubic feet of storage. • Requires dewatering provisions. • Provides a high -flow bypass that will not clog under normal use at a construction site. • Insert the catchbasin filter in the catchbasin just below the grating. Curb Inlet Protection with Wooden Weir — Barrier formed around a curb inlet with a wooden frame and gravel. • Use wire mesh with Y2-inch openings. • Use extra strength filter cloth. • Construct a frame. • Attach the wire and filter fabric to the frame. • Pile coarse washed aggregate against wire/fabric. • Place weight on frame anchors. Block and Gravel Curb Inlet Protection — Barrier formed around a curb inlet with concrete blocks and gravel. See Figure 4.2.9. • Use wire mesh with I/2-inch openings. • Place two concrete blocks on their sides abutting the curb at either side of the inlet opening. These are spacer blocks. • Place a 2x4 stud through the outer holes of each spacer block to align the front blocks. • Place blocks on their sides across the front of the inlet and abutting the spacer blocks. • Place wire mesh over the outside vertical face. • Pile coarse aggregate against the wire to the top of the barrier. Curb and Gutter Sediment Barrier — Sandbag or rock berm (riprap and aggregate) 3 feet high and 3 feet wide in a horseshoe shape. See Figure 4.2.10. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-84 r -• f r • Construct a horseshoe shaped berm, faced with coarse aggregate if using riprap, 3 feet high and 3 feet wide, at least 2 feet from the inlet. • Construct a horseshoe shaped sedimentation trap on the outside of the berm sized to sediment trap standards for protecting a culvert inlet. Maintenance • Inspect catch basin filters frequently, especially after storm events. Standards Clean and replace clogged inserts. For systems with clogged stone filters: pull away the stones from the inlet and clean or replace. An alternative approach would be to use the clogged stone as fill and put fresh stone around the inlet. • Do not wash sediment into storm drains while cleaning. Spread all excavated material evenly over the surrounding land area or stockpile and stabilize as appropriate. Approved as Ecology has approved products as able to meet the requirements of BMP Equivalent C220. The products did not pass through the Technology Assessment Protocol — Ecology (TAPE) process.. Local jurisdictions may choose not to accept this product approved as equivalent, or may require additional testing prior to consideration for local use. The products are available for review on Ecology's website at http://www.ecy.wa.gov/programsRvq/stormwater/newtech/equivalent.html Volume II — Construction Stormwater Pollution Prevention - December 2014 4-85 1Adire Screen or Filter Fabric NOTES: 1. Use block and gravel type sediment barrier when curb inlet is located in gently sloping street segment, where water can pond and allow sediment to separate from runoff. 2. Barrier shall allow for overflow from severe storm event. 3. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. Figure 4.2.9 — Block and Gravel Curb Inlet Protection Volume H — Construction Stormwater Pollution Prevention - December 2014 4-86 Plan View Back of Sidewalk RUNOFF RUNOFF Burlap Sacks to Overlap onto Curb SWAY-----\ Gravel Filled Sandbags Stacked Tightly Catch Basin Curb Inlet g A Back of Curb NOTES: 1. Place curb type sediment barriers on gently sloping street segments, where water can pond and allow sediment to separate from runoff. 2. Sandbags of either burlap or woven 'geotextilefabric, are filled with gravel, layered and packed tightly. 3. Leave a one sandbag gap in the top row to provide a spillway for overflow. 4. Inspect barriers and remove sediment after each storm event. Sediment and gravel must be removed from the traveled way immediately. Figure 4.2.10 — Curb and Gutter Barrier Volume II — Construction Stormwater Pollution Prevention - December 2014 4-87 BMP C240: Sediment Trap Purpose Conditions of Use A sediment trap is a small temporary ponding area with a gravel outlet used to collect and store sediment from sites cleared and/or graded during construction. Sediment traps, along with other perimeter controls, shall be installed before any land disturbance takes place in the drainage area. Prior to leaving a construction site, stormwater runoff must pass through a sediment pond or trap or other appropriate sediment removal best management practice. Non -engineered sediment traps may be used on -site prior to an engineered sediment trap or sediment pond to provide additional sediment removal capacity. It is intended for use on sites where the tributary drainage area is less than 3 acres, with no unusual drainage features, and a projected build -out time of six months or less. The sediment trap is a temporary measure (with a design life of approximately 6 months) and shall be maintained until the site area is permanently protected against erosion by vegetation and/or structures. Sediment traps and ponds are only effective in removing sediment down to about the medium silt size fraction. Runoff with sediment of finer grades (fine silt and clay) will pass through untreated, emphasizing the need to control erosion to the maximum extent first. Whenever possible, sediment -laden water shall be discharged into on -site, relatively level, vegetated areas (see BMP C234 — Vegetated Strip). This is the only way to effectively remove fine particles from runoff unless chemical treatment or filtration is used. This can be particularly useful after initial treatment in a sediment trap or pond. The areas of release must be evaluated on a site -by -site basis in order to determine appropriate locations for and methods of releasing runoff. Vegetated wetlands shall not be used for this purpose. Frequently, it may be possible to pump water from the collection point at the downhill end of the site to an upslope vegetated area. Pumping shall only augment the treatment system, not replace it, because of the possibility of pump failure or runoff volume in excess of pump capacity. All projects that are constructing peiiiianent facilities for runoff quantity control should use the rough -graded or final -graded permanent facilities for traps and ponds. This includes combined facilities and infiltration facilities. When permanent facilities are used as temporary sedimentation facilities, the surface area requirement of a sediment trap or pond must be met. If the surface area requirements are larger than the surface area of the permanent facility, then the trap or pond shall be enlarged to comply with the surface area requirement. The permanent pond shall also be divided into two cells as required for sediment ponds. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-102 r • f ) Either a permanent control structure or the temporary control structure (described in BMP C241, Temporary Sediment Pond) can be used. If a permanent control structure is used, it may be advisable to partially restrict the lower orifice with gravel to increase residence time while still allowing dewatering of the pond. A shut-off valve may be added to the control structure to allow complete retention of stormwater in emergency situations. In this case, an emergency overflow weir must be added. A skimmer may be used for the sediment trap outlet if approved by the Local Permitting Authority. Design and • See Figures 4.2.16 and 4.2.17 for details. Installation • If permanent runoff control facilities are part of the project, they Specifications should be used for sediment retention. To determine the sediment trap geometry, first calculate the design surface area (SA) of the trap, measured at the invert of the weir. Use the following equation: SA = FS(Q2IVs) where Q2 = Design inflow based on the peak discharge from the developed 2-year runoff event from the contributing drainage area as computed in the hydrologic analysis. The 10-year peak flow shall be used if the project size, expected timing and duration of construction, or downstream conditions warrant a higher level of protection. If no hydrologic analysis is required, the Rational Method may be used. Vs = The settling velocity of the soil particle of interest. The 0.02 mm (medium silt) particle with an assumed density of 2.65 g/cm3 has been selected as the particle of interest and has a settling velocity (Vs) of 0.00096 ft/sec. FS = A safety factor of 2 to account for non -ideal settling. Therefore, the equation for computing surface area becomes: SA = 2 x Q2/0.00096 or 2080 square feet per cfs of inflow Note: Even if permanent facilities are used, they must still have a surface area that is at least as large as that derived from the above formula. If they do not, the pond must be enlarged. To aid in determining sediment depth, all sediment traps shall have a staff gauge with a prominent mark 1-foot above the bottom of the trap. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-103 • Sediment traps may not be feasible on utility projects due to the limited work space or the short-term nature of the work. Portable tanks may be used in place of sediment traps for utility projects. Maintenance • Sediment shall be removed from the trap when it reaches 1-foot in Standards depth. • Any damage to the pond embankments or slopes shall be repaired. Surface area determined at top of weir l' Min. Overflow T 1' Min. '1- 3.5-5' Flat Bottom 1.5' Min, 1 Note: Trap may be formed by berm or by partial or complete excavation 4' in. I : • 1' Min. 3/4" - 1,5" Washed gravel \ 2"-4" Rock RipRap Geotextile Discharge to stabilized conveyance, outlet, or level spreader Figure 4.2.16 - Cross Section of Sediment Trap 6' Min. 1' Min. depth overflow spillway Native soil or compacted backfill Geotextile Min. 1' depth 2"-4- rock Min. 1' depth 3/4-1.5" washed gravel Figure 4.2.17 - Sediment Trap Outlet Volume H - Construction Stormwater Pollution Prevention - December 2014 4-104 2 • BMP C252: High pH Neutralization Using CO2 Purpose When pH levels in stormwater rise above 8.5 it is necessary to lower the pH levels to the acceptable range of 6.5 to 8.5, this process is called pH neutralization. pH neutralization involves the use of solid or compressed carbon dioxide gas in water requiring neutralization. Neutralized stormwater may be discharged to surface waters under the General Construction NPDES permit. Neutralized process water such as concrete truck wash -out, hydro - demolition, or saw -cutting slurry must be managed to prevent discharge to surface waters. Any stormwater contaminated during concrete work is considered process wastewater and must not be discharged to surface waters. Reason for pH Neutralization: A pH level range of 6.5 to 8.5 is typical for most natural watercourses, and this neutral pH is required for the survival of aquatic organisms. Should the pH rise or drop out of this range, fish and other aquatic organisms may become stressed and may die. Calcium hardness can contribute to high pH values and cause toxicity that is associated with high pH conditions. A high level of calcium hardness in waters of the state is not allowed. The water quality standard for pH in Washington State is in the range of 6.5 to 8.5. Ground water standard for calcium and other dissolved solids in Washington State is less than 500 mg/l. Conditions of Use Causes of High pH: High pH at construction sites is most commonly caused by the contact of stormwater with poured or recycled concrete, cement, mortars, and other Portland cement or lime containing construction materials. (See BMP C151: Concrete Handling for more information on concrete handling procedures). The principal caustic agent in cement is calcium hydroxide (free lime). Advantages of CO Sparging: • Rapidly neutralizes high pH water. • Cost effective and safer to handle than acid compounds. • CO2 is self -buffering. It is difficult to overdose and create harmfully low pH levels. • Material is readily available. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-124 Design and Installation Specifications The Chemical Process: When carbon dioxide (CO2) is added to water (H2O), carbonic acid (H2CO3) is formed which can further dissociate into a proton (H+) and a bicarbonate anion (HCO3-) as shown below: CO2 + H2O E--> H2CO3 H H+ + HCO3" The free proton is a weak acid that can lower the pH. Water temperature has an effect on the reaction as well. The colder the water temperature is the slower the reaction occurs and the warmer the water temperature is the quicker the reaction occurs. Most construction applications in Washington State have water temperatures in the 50°F or higher range so the reaction is almost simultaneous. Treatment Process: High pH water may be treated using continuous treatment, continuous discharge systems. These manufactured systems continuously monitor influent and effluent pH to ensure that pH values are within an acceptable range before being discharged. All systems must have fail safe automatic shut off switches in the event that pH is not within the acceptable discharge range. Only trained operators may operate manufactured systems. System manufacturers often provide trained operators or training on their devices. The following procedure may be used when not using a continuous discharge system: 1. Prior to treatment, the appropriate jurisdiction should be notified in accordance with the regulations set by the jurisdiction. 2. Every effort should be made to isolate the potential high pH water in order to treat it separately from other stormwater on -site. 3. Water should be stored in an acceptable storage facility, detention pond, or containment cell prior to treatment. 4. Transfer water to be treated to the treatment structure. Ensure that treatment structure size is sufficient to hold the amount of water that is to be treated. Do not fill tank completely, allow at least 2 feet of freeboard. 5. The operator samples the water for pH and notes the clarity of the water. As a rule of thumb, less CO2 is necessary for clearer water. This information should be recorded. 6. In the pH adjustment structure, add CO2 until the pH falls in the range of 6.9-7.1. Remember that pH water quality standards apply so adjusting pH to within 0.2 pH units of receiving water (background pH) is recommended. It is unlikely that pH can be adjusted to within 0.2 pH units using dry ice. Compressed carbon dioxide gas should be introduced to the water using a carbon dioxide diffuser located near Volume II — Construction Stormwater Pollution Prevention - December 2014 4-125 Maintenance Standards the bottom of the tank, this will allow carbon dioxide to bubble up through the water and diffuse more evenly. 7. Slowly discharge the water making sure water does not get stirred up in the process. Release about 80% of the water from the structure leaving any sludge behind. 8. Discharge treated water through a pond or drainage system. 9. Excess sludge needs to be disposed of properly as concrete waste. If several batches of water are undergoing pH treatment, sludge can be left in treatment structure for the next batch treatment. Dispose of sludge when it fills 50% of tank volume. Sites that must implement flow control for the developed site must also control stormwater release rates during construction. All treated stormwater must go through a flow control facility before being released to surface waters which require flow control. Safety and Materials Handling: • All equipment should be handled in accordance with OSHA rules and regulations. • Follow manufacturer guidelines for materials handling. Operator Records: Each operator should provide: • A diagram of the monitoring and treatment equipment. • A description of the pumping rates and capacity the treatment equipment is capable of treating. Each operator should keep a written record of the following: • Client name and phone number. • Date of treatment. • Weather conditions. • Project name and location. • Volume of water treated. • pH of untreated water. • Amount of CO2 needed to adjust water to a pH range of 6.9-7.1. • pH of treated water. • Discharge point location and description. A copy of this record should be given to the client/contractor who should retain the record for three years. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-126 BMP C253: pH Control for High pH Water Purpose Conditions of Use Design and Installation Specifications When pH levels in stormwater rise above 8.5 it is necessary to lower the pH levels to the acceptable range of 6.5 to 8.5, this process is called pH neutralization. Stormwater with pH levels exceeding water quality standards may be treated by infiltration, dispersion in vegetation or compost, pumping to a sanitary sewer, disposal at a permitted concrete batch plant with pH neutralization capabilities, or carbon dioxide sparging. BMP C252 gives guidelines for carbon dioxide sparging. Reason for pH Neutralization: A pH level range of 6.5 to 8.5 is typical for most natural watercourses, and this pH range is required for the survival of aquatic organisms. Should the pH rise or drop out of this range, fish and other aquatic organisms may become stressed and may die. Causes of High pH: High pH levels at construction sites are most commonly caused by the contact of stormwater with poured or recycled concrete, cement, mortars, and other Portland cement or lime containing construction materials. (See BMP C151: Concrete Handling for more information on concrete handling procedures). The principal caustic agent in cement is calcium hydroxide (free lime). Disposal Methods: Infiltration • Infiltration is only allowed if soil type allows all water to infiltrate (no surface runoff) without causing or contributing to a violation of surface or ground water quality standards. • Infiltration techniques should be consistent with Volume V, Chapter 7 Dispersion Use BMP T5.30 Full Dispersion Sanitary Sewer Disposal • Local sewer authority approval is required prior to disposal via the sanitary sewer. Concrete Batch Plant Disposal • Only permitted facilities may accept high pH water. • Facility should be contacted before treatment to ensure they can accept the high pH water. Stormwater Discharge Any pH treatment options that generate treated water that must be discharged off site are subject to flow control requirements. Sites that must implement flow control for the developed site must also control Volume II — Construction Stormwater Pollution Prevention - December 2014 4-127 stormwater release rates during construction. All treated stormwater must go through a flow control facility before being released to surface waters which require flow control. Volume II — Construction Stormwater Pollution Prevention - December 2014 4-128 C. Correspondence Corresponsdence will be included as it occurs. Page 135 D. Site Inspection Form 1 �� ��� ���� ��� Form � Project Name Permit # Inspection Date Time Name ofCertified Erosion Sediment Control Lead orqualified inspector if less than one acre Print Name: Approximate rainfall amount since the last inspection (in inches): Approximate rainfall amount in the last 24 hours (in inches): Current Weather Clear A'Type mfinspection: Weekly Mist Rain Post Storm Event 0^Phase of Active Constrwctilmm(check all that opply): _ Pre Construction/installation mferosion/sediment controls Concrete pours _ Uffsitehnp,ovements C. Questions: Wind _ Fog Vertical Construction/buildings Site temporary stabilized _ Infrastructure/storm/roads Utilities Final stabilization 1. Were all areas ofconstruction and discharge points inspected? Yes No J. Did you observe the presence of suspended sediment, turbidity, discoloration, or oil sheen Yes No 3. Was awater quality sample taken during inspection? (refer topermit conditions 54& SS) Yes No 4. Was there a turbid discharge 250 NTU or greater, or Transparency 6 cm or less?* Yes No S. |fyes to#4was itreported toEcology? Yes No 6. Is pH sampling required? pH range required ioG.5toO.S. Yes No _ _ Ifanswering yes toadischarge, describe the event, include when, where, and why it happened; what action was taken, and when. *If answering yes to#4record NTV/T, nspaenny"vid`cuntinua!samp|ingdailyund|tudbidityis 25NTUurless/ transparency is33 cm or greater. Sampling Results: Date: Parameter Method (circle one) Result NTLI cm pH Turbidity tube, meter, laboratory pH Paper, kit, meter ���D��*� Site Inspection ---------- Stormwater -- -- -- -^r--- - C. Check the observed status of all items. Provide "Action Required "details and dates. Element # Inspection BN8ps Inspected BN8Pnemdo maintenance BMNp failed Action required (describe in smctiomF) yes no n/a l Clearing Limbs Before beginning land disturbing activities are all clearing limits, natural resource areas (streanms, wetlands, buffers, trees) protected with barriers orsimilar BK8Ps?(high visibility recommended) Z Construction Access Construction access iostabilized with quarry spaUsorequivalent 8K«Ptnprevent sediment from being tracked onto roads? Sediment tracked onto the road way was cleaned thoroughly atthe end of the day or more frequent as necessary. 3 Control Flow Rates Are flow control measures installed to control s1ormvxatervolumes and velocity during construction and do they protect downstream properties and waterways from erosion? |fpermanent infiltration ponds are used for flow control during construction, are they protected from siltation? 4 Sediment Controls All perimeter sediment controls (e.Q.silt fence, wattles, compost socks, berms, etc.}installed, and maintained inaccordance with the StormxvaterPollution Prevention P|an(SVVppp). Sediment control 8MPs(sediment ponds, traps, filters etc.)have been constructed and functional asthe first step ofgrading. Stormxvaterrunoff from disturbed areas isdirected tosediment removal ByNP. 5 Stabilize Soils Have exposed un'm/orkedsoils been stabilized with effective 8K4P toprevent erosion and sediment deposition? Construction Stormwater Site Inspection Form Ekymnem± # Inspection MIPS Inspected @K*Pmeeda maintenance BMp failed Action required (describe in semt|onF) yes no n/a G Stabilize Soils Cont. Are stockpiles stabilized from erosion, protected with sediment trapping measures and located away from drain inlet, waterways, and drainage channels? Have soils been stabilized atthe end of the shift, before aholiday orweekend ifneeded based onthe weather forecast? G Protect Slopes Has stormwoterand ground water been diverted away from slopes and disturbed areas with interceptor dikes, pipes and urswa|es? boff-site storm water managed separately from sturmwatergenerated onthe site? |sexcavated material placed on uphill side oftrenches consistent with safety and space considerations? Have check dams been placed at regular intervals within constructed channels that are cut down aslope? 7 Drain Inlets Storm drain inlets made operable during construction are protected. Are existing storm drains within the influence ofthe project protected? 8 Stabilize Channe|and Outlets Have all on -site conveyance channels been designed, constructed and stabilized toprevent erosion from expected peak flows? (sstabilization, including armoring material, adequate toprevent erosion ofoutlets, adjacent stream banks, slopes and downstream conveyance systems? 9 Control Pollutants � Are waste materials and demolition debris handled and disposed ufto prevent contamination ofstormv,ater? Has cover been provided for all chemicals, liquid products, petroleum products, and other material? Has secondary containment been provided capable ofcontaining 110% ofthe volume? Were contaminated surfaces cleaned immediately after aspill incident? Were 8MPsused toprevent contamination ofstormwater by pH modifying sources? / ' .. � , ' ^' � ^~ ' . � ' r'� ^' `^ , I u�� ���� ��°������ ater Site Inspection Form Element # Inspection BUVIPs Inspected 0N0Pneeds maintenance BIVIP failed Action required (describe in section F) yes no n/a 9 Cont Wheel wash wastewater ishandled and disposed ufproperly. lO Control Dpwatering Concrete washout indesignated areas. Nowashout orexcess concrete nnthe ground. De"vateringhas been done toan approved source and incompliance with the SVVPPP. Were there any clean non turbid devvatehngdischanges7 11 Maintain BMP Are all temporary and permanent erosion and sediment control 8MPs maintained to perform as intended? lZ Manage the Project ' Has the project been phased tothe maximum degree practicable? Has regular inspection, monitoring and maintenance been performed us required by the permit? Has the 5vvPppbeen updated, implemented and records maintained? 13 Protect LID |sall 8ioretentionand Rain Garden Facilities protected from sedimentation with appropriate 8K8Po? |sthe 8iuretenhonand Rain Garden protected against over compaction of construction equipment and foot traffic toretain its infiltration capabilities? Permeable pavements are clean and free ofsediment and sediment laden - water runoff. Muddy construction equipment has not been nnthe base material orpavement. Have soiled permeable pavements been cleaned ufsediments and pass infiltration test asrequired by stn,mwatermonua| methodology? Heavy equipment has been kept off existing soils under LID facilities to retain infiltration rate. E. Check all areas that have been inspected. ~^ All in place 8K8Ps All disturbed soils | | All concrete wash out area All material storage areas All discharge locations All equipment storage areas All construction entrances/exits I Construction Stormwater Site Inspection Form F. Elements checked "Action Required" (section D) describe corrective action to be taken. List the element number; be specific on location and work needed. Document, initial, and date when the corrective action has been completed and ins ected. Element # Description and Location Action Required Completion Date Initials Attach additional page if needed Sign the following certification: "I certify that this report is true, accurate, and complete, to the best of my knowledge and belief" Inspected by: (print) Title/Qualification of Inspector: (Signature) Date: Page 5 _ r 7 A r No .1 7 - ! r L E. Construction Stormwater General Permit (CSWGP) (Application for a permit is in process) Page 137 F. 303(d) List Waterbodies / TMDL Waterbodies Information Page 138 September 25, 2019 Sammamish River 303(d) list for Temperature and pH • In St 5 I3HIn 5I Site Vicinity: 3481 S 152nd SIti \y 1;ihh51 Washington Memel tal Park 4 Cemetery Ftherton Crest Canreterr 0 z S 144tn SI 0 S 1491h S1 5150thSI t 1 58th St hr 3 fit Sj'rK, S 1601h 5t orb 51r.)alh st S lt6th St 31:0 S 168111 St If; `,1MIT) St a d T; U, L 4. i it)c ;, S 1721ti St Q V 1 7 5 113rd SI $ J S 175Ih SI Q rf u A ruler(oil4P"- p4� y1 d� l q�f Westfield Southtenter .(1 tn Tukwila Stranie(iilv:1 rar:.vir; REI Costa, ' Far* Fun Cengrs Sources. Esri. HERE, Garmin, Intermap, increment P Corp„ GEBCO USGS, FAO, NPS, NRCAN, GeoBase, IGN. Kadaster NL, Ordnance Survey, Esn Japan, METI, Esn China (Hong Kong). (c) OpenStreetMap contributors, and Miles 0 0.25 0.5 1 Assessed Waters/Sediment Water 4.0 Category 5 - 303d No Category 4C Category 4B Category 4A Category 2 Category 1 Sediment ® Category 5 - 303d ® Category 4C Ft?, Category 4B El Category 4A '// Category 2 71/ Category 1 DEPARTMENT OF ECOLOGY 110111 State of Washington G. Contaminated Site Information The sae is not contaminated. Page 139 7 7 • r H. Engineering Calculations (See Section 2.1.4 for Calculations) Page 140 • -S • BLUELINE Bellwether TOD Apartments Tukwila, Washington Date September 26, 2019 REVIEWED FOR CODE COMPLIANCE APPROVED NOV 15 2019 City of Tukwila BUILDING DIVISION lqo3t7 Technical Information Report Prepared for Johnson Braund, INC. 15200 52nd Ave S Seattle, WA 98188 BluelineJob No. 18-183 Prepared by: James Reynes, EIT Reviewed by: Jon Koepfgen, PE CITRECEIVED Y OF T UKWILA SEP 30 2019 PERMIT CENTER BELLWEATHER TOD APARTMENTS TABLE OF CONTENTS SECTION 1 PROJECT OVERVIEW ...... ...... ........ .............. .......... ........._ ...... ........ 1.1 Existing Conditions Exhibit 1.2 Developed Conditions Exhibit 1.3 SECTION 2 CONDITIONS AND REQUIREMENTS SUMMARY............... ...... ........ .......... 2.1 SECTION 3 OFFSITE ANALYSIS 3.1 3,1 Level I Downstream Analysis ..........--... ...... ...... ...... _ ..... ....... ....... ..... 3.1 Task 1: Define and Map the Study Area 3.1 Task 2: Resource Review 3.1 Task 3 and Task 4: Field Inspection and Drainage System Description 3.4 Task 5: Mitigation of Existing or Potential Problems 3.4 Downstream Drainage Exhibit 3.6 Downstream Drainage Complaints 3.7 Existing Downstream Drainage Path Photographs 3.8 Proposed Downstream Drainage Path Photographs 3.12 SECTION 4 DEVELOPED SITE CONDITIONS 4.1 Existing Conditions 4.1 Developed Conditions 4.2 4.1 Flow Control Analysis and Design 4.4 4.2 Water Quality System 4.16 4.3 Low Impact Development BMPs 4.18 SECTION 5 CONVEYANCE DESIGN 5.1 PUMP DESIGN BETWEEN the Pump System AND CB 2 5.1 Conveyance System Design Tributary to Detention Vault 5.2 On -Site Pipe Capacity 5.3 SECTION 6 SPECIAL REPORTS AND STUDIES 6.4 SECTION 7 OTHER PERMITS 7.1 SECTION 8 TESC ANALYSIS AND DESIGN 8.1 SECTION 9 BOND QUANTITIES AND FACILITIES ....... .... ...,.... ....... 9.1 SECTION 10 OPERATIONS AND MAINTENANCE 10.1 JOB #18-183 Technical Information Report BELLVVEATHERT{}OAPARTMENTS Section 1 Project Overview The project is located at 3481S152 d Street, Tukwila, NA98188.More generally, the site is located inthe 8NY4of Section 22, Township 23 N, Range 4 E, W.M. Vicinity Map- not to scale Section 6 of this report. Refer to the Existing & Developed Conditions Exhibits included onthe following pages. The development consists ofthree parcels, parcel numbers 0043000108'0043000112, and OO43OOO116.The development �ndudes1.29acres wf developed land on'site,and anadditional O.O9acres of frontage improvements along NE152"«St. The existing site contains four (4) single-family residences with carports, fencing, sheds, gravel driveways, trees, residential landscaping, and anaccess road which will all beremoved prior tofinal stabilization. Onsiteruroffiogenerated from one drainage basin. The site ispart ofthe Gilliam Creek drainage basin. ALevel 1DmmnstreamAnalysis included |n Section 3 of this report. AGeotechnico|Report was preparedforthe site by9onGE[1 INC. onAugust 7 1^%017.On-site soils are predominantly VashonTill from depths ofapproximately ].S'to 12' below grade. Till soils are not suitable for infiltration asexplained in The site isbounded bymulti-family landusetothe south, east, and west. S152"d Street bounds the site tothe north. The proposed development will improve existing infrastructure to support a multifamily apartment building as shown in the Developed Conditions Exhibit included at the end of this section, Stormwater elements will be designed in accordance with the 2016 King County Surface Water Design Manual (KCSWDM), as adopted and amended by the City of Tukwila. The proposed development will create more than 5,000 SF of new and replacement impervious surface, requiring the project to provide a flow control facility per Section 1,23.1 of the 2016 King County Surface Water Design Manual (KCSWDM), and water quality treatment per Section 1.Z.8.Iofthe K[5VVDM. StormwaterLow Impact Development (L|D)features will beprovided tothe maximum extent feasible per Section 1.2.9.2.2. LID BK8P'Flow Control, and Water Quality design consideration are discussed further inSection 4.The project issubject tuFull Drainage Review per Section 1.1.2mfthe KCSWDM. The requirements for the Full Drainage Review are listed in Section 2. JOB #18-um Technical Information Report i'z VGVGLur .y VUIVVII!WINO GAf%DIT EX CB ;`:119 TYPE I 1 RIM 335.68 / 12"CONC 'IE334.41 (E) S 152ND S UPSTREAM IMPERVIOUS AREA (001 AC) FRONTAGE BASIN (0,06 AC) PROPOSED BASIN BOUNDARY (1,35 AC) BYPASS IN -LIEU BASIN RRXCB 86, TYPE I (0,03 AC) I 12�CONCJE 330,71 332.46 EX CB;:087 TYPE/ (E) RIM 327.25 12" CONC IE 3 5.90 (W) DIIE327(E) 12"DIIE; lrlrl�l��� ni6a1��mmo 326.28 0.03AC CATCH BASIN (TYR) STORM DRAINAGE FORCE MAIN ,7717777 PROPOSED PARKING LOT (15,767 SF) DUPLEX P SYSTEM BIOPOD 12" CONC SD 1.11, Mt AIR N SCALE: 1" = 40' n ILUELINE W JOB NUMBER: 18-183 FIGURE DC EX CB N8119, RIM 335,68 2" CONC 1E:334 MN GAIGIIIVL7 L+UIVLJIIIUIW GRP11Q►1 EX CB 1E8086, TYPE I RIM 332.46 112' CONC IFI 330.71 (E) 12" CONC IE JP' 33366 (E) 7 1 R9rA Q09 AC, EXISTING TREE (TO BE REMOVED, TYP,) EXISTING GRAVEL DRIVEWAY (TO BE REMOVED) EXISTING HOUSE (TO BE REMOVED) EXISTING FENCE (1O BE REMOVED) E70S11NC BASIN WEARY (1,38 AC) EX CB /8087, TYPE I RIM 327.25 12" CONC IE 325,90 (W) 12°DI IE 325,87 (E) -SCAz LE: it" _ 40' PARCEL KUM AC) EXISTING CARPORT (TO BE REMOVED) EXISTING HOUSE (T0 BE REMOVED) EXISTING FENCE (TO BE REMOVED) EXISTING SHED (TO BE REMOVED) EXISTING HOUSE (TO BE REMOVED) EXISTING CARPORT (TO BE REMOVED) EXISTNG FENCE ((l0 BE REMOVED) ?STING HOUSE BE REMOVED) '11/ry'/114L-I' EXISTING FENCE (TO BE REMOVED) —X EXISTING SHED 1O BE REMOVED EXISTING ASPHALT ACCESS ROAD (TO BE REMOVED) N n U !WHINE 0 m 0 0 0 JOB NUMBER: 18-183 RGURE EC BELLVVEATHERTOOAPARTMENTS Section 2 Conditions and Requirements Summary Core and special requirements aslisted inthe 2016 KCSWCIVI,and adopted by the City of Tukwila, and the requirements for the Full Drainage Review are addressed as they pertain to the site development, CORE REQUIREMENT #1: DISCHARGE ATTHE NATURAL LOCATION See Section 3 of this report. The existing condition shows the site has one discharge location. |ngenera|, drainage from the site sheet flows from north to south before flowing to a system that drains to Gilliam Creek, approximately 1,200 feet to the southeast. in the developed condition, onsite runoff will be collected in a tigh||inesystem and conveyed north tothe frontage along S 152"uStreet, Storm water then conveys east approximately 1,400 feet to Gilliam Creek. Although both discharge to Gilliam Creek drainage basin, the existing and proposed downstream paths do not meet within X-mile. The City of Tukwila Drainage Basin map is located inSection 3ofthis report, CORE REQUIREMENT #2: OFF -SITE ANALYSIS See Section 3ofthis report. ALevel 1Downstream Analysis was prepared bvThe 0veUneGroup. The findings of the analysis along with corresponding site photos can be found in Section 3.1. CORE REQUIREMENT #3: FLOW CONTROL See Section 4. According to the City of Tukwila Drainage Basins and Flow Control Standards Map, the site is located in a Level 2 Flow Control area. This designation triggers flow control requirements per Section 1.2.3.1 of the 2016 KCSWDIVI. A detention vault is proposed and will provide flow control as discussed in Section 4. CORE REQUIREMENT#4: CONVEYANCE SYSTEM See Section S.The conveyance system design has been included insection 5. Per the 2016 KCSWDM, the system must convey the 100-yea�24-hourstorm event without overtopping orsurcharging, CORE REQUIREMENT #5: EROSION AND SEDIMENT CONTROL (ESC SeeSpctionQ. The temporary erosion and sedimentation control (TESC) plan will consist of temporary measures (rock entrance, inlet protection, silt fence, sediment trap, etc.) as well as permanent measures (hydroseeding and landscaping). A SWPPP, that includes the finalized version of this plan, has been provided under separate cover. — CORE REQU|REIVIENT#6:OPERATIONS AND MAINTENANCE SeeSection10. Operations and Maintenance information will be provided prior to perrrit issuance. Jmm#zoaoa Technical Information Report 2.1 BELLVVEATHERTO[)APARTMENTS CORE REQUIREMENT #7: FINANCIAL GUARANTEES AND LIABILITY See Section 9. Financial Guarantees and Liability will be provided prior to permit issuance. CORE REQUIREMENT #8: WATER QUALITY See Section 4. The proposed improvements include construction of a multi -family developmentwith associated parking, resulting in 5,000 SF of new and replaced pollution generating impervious surface (PGIS). The PGIS added to the site includes the driveway and the parking lot which will be treated using a0ioPodsystem. This will provide Enhanced Water Quality, before discharging into a detention vault. CORE REQUIREMENT #9: FLOW CONTROL BMPS The proposed improvements encompass greater than ��sq. ft. ofarea, but bnot aLarge Rural Lot. Therefore, flow control BMPs have been evaluated based on Large Lot BMP Requirements per Section 1.2.9,2.2 of the 2016 KCSWDM. Per the high impervious lot coverage, non -infiltrating soils, and lack of lengthy vegetative stormwater flowpaths, all flow control BMPs will be infeasible except compost amended soils, This will be implemented inlandscape areas when possible. See Section 4. Specio Recmirempnt#1: Other Adopted Requirements There are no known additional requirements for the subject project. Special Requirement #2: FloodplainIFloodway The subject site does not contain and is not adjacent toaflood hazard area. This Special Requirement is therefore, not applicable. Special Requirement #3/ Flood Protection Facilities The site does not rely on an existing flood protection facility and will not modify or construct a new flood protection facility, This Special Requirement is therefore, not applicable. Special Requirement #4: Source Control Source control BMPs have been included within the SWPPP provided under separate cover. Special Requirement #5: Oil Control The proposed project is neither an industrial development or a high -use site. This Special Requirement, therefore, is not applicable. Jma#zu183 Technical Information Report 2.2 BELLVVEATHERTD[}APARTMENTS Section 3 Of�'te Analysis A Level I Downstream Analysis is included in this section. 3.1 LEVEL I DOWNSTREAM ANALYSIS TASK 1: DEFINE AND MAP THE STUDY AREA ADownstream Drainage ExhibitandOownstreamDrainagePhotoQnaphsaneindudedottheendofdhissection. TASK 2: RESOURCE REVIEW The best available resource information, including King County iMapand City of Tukwila resource maps, were reviewed for existing urpotential problems. The following basummary of the findings trom the information used in preparing this report, ° The basin discharge location is part of the Gilliam Creek drainage basin (City of Tukwila). * The site does not contain wetlands (City of Tukwila and King County iMap). ~ The site does not contain streams and is not located within a floodplain (City of Tukwila and King County ° The site is not located in a Seismic Hazard Area (City of Tukwila and King County iMap). * The site is not located in a Landslide Hazard Area (City of Tukwila and King County iMap). * The site isnot located inanErosion Hazard Area (King County iK8ap). There are nodownstream drainage complaints along the downstream path that the project needs 1m note. Please referto the email correspondence with Ryan Larson and Jeff Heglund of the City of Tukwila atthe end ofthis section. Joe#zuams Technical Information Report 3.1 BELLWEATHER TOD APARTMENTS L4g4011 ... Iwci.4.) 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Imp City of Tukwila Critical Areas Map JOB #18-183 Technical Information Report 3.2 MIN �+r • BELLWEATHER TOD APARTMENTS SECTION 5.9 SURFACE WATER MAPS 5.9 1 Drainage Basins and Flow Control Standards a t,y Kirin county Borten ties MalneS Riverton Creek" Basin Mercer Island King County fuwamtsh Rsver Basra Southgate Creak Basin t 5 Mani +_.:reek Basin Sea lac Tultwit Sousa; B sin- Neighbor -in Jurisdictions ,hater Body:^Aletland I 1 Basal Boundary L _ J Tukwila • Pump Station P1 ! Basin • i{P'ttrn n Ptaca / Acres Basin Strartcler Pump Station Basin Meast Basin Keot Lower Mill Creek Basin Lever 2 - Conservation to Ecist;rg Level 2 - Conserratton . to Forested Basic - Peal Rate to ExAtrg Per Tukwila South Development Agreement City of Tukwila Drainage Basins and Flow Control Standards Map JOB #18-183 Technical Information Report Janage Eason zinc -i0.4 :u.bd Jdrelars ?_ca'e �V r: Lre•.aT anew= 3.3 8ELLVVEATHERTOOAPARTMENTS TASK 3 AND TASK 4: FIELD INSPECTION AND DRAINAGE SYSTEM DESCRIPTION A field inspection was conducted onMarch 212019,aclear day with temperatures around 65*F. Please reference the Downstream Drainage Exhibit, and Downstream Drainage Photographs included at the end of this section. Onsite Basin The existing site contains four (4) single-family residences with carports, fencing, sheds, gravel driveways, trees, residential landscaping, and an access road which will all be removed priorto final stabilization. According to the Geotechnical Report prepared by PanGEO, INC. on August 7, 2017, on -site soils are identified as medium dense to very dense till soils. The site contains a single drainage basin which slopes to the south and is ultimately tributary to Gilliam Creek. Please see the Exi5ting Conditions Exhibit at the end of this section. Upstream Basin In the existing condition, upstream runoff from S 152 n1 is collected by a swale located in the frontage of the properties and is routed east along S 152nd . In the developed condition, upstream runoff will be collected in pnoposedgu1terandcatnhbasina|onQthesouth»ideofS15I"«StreetcoUectingapprouimate|yO.0lacresof upstream PG|Sanea. Existing Downstream Drainage Path Drainage from the onsite basin currently sheet flows south towards the southern parcel boundary (Photo 1A). Runoff is then directed through the parking lot of the parcel directly south (#0043000200) of the site through an inverted crown roadway (Photo 2A). The stormwater travels through the parking lot before it is intercepted by a trench drain in the existing driveway (Photo 3A). From the trench drain, flows travel southeast towards the catch basin located in the center of Southcenter Boulevard. Flows are then conveyed into a dilch with a rock outfall pad (Photo 4A). Stormwater is then conveyed through a series of ditches, culverts, and manholes (Photos 5A-6A) until it outfalls into Gilliam Creek near the intersection of 40th Ave S and 39th Lane South foughly 0.25 miles downstream (Photo 7A). Proposed DownstreamDrainage Path On -site stormwater will be collected and pumped to a proposed CB to be installed at the inlet of an existing culvert at the eastern edge of the project frontage (Photo 1B). The stormwater is conveyed east along S 152 nd Street until it reaches the east side of 42 nd Ave S (Photos 213-1613). From this catch basin, the stormwater continues east into a final manhole (Photo 17B) before discharging to the north into the 42 n' Ave S Detention Pond (Photo 18B). From the detention pond, the water is conveyed east in a tightlined system into Gilliam Creek which isapproximately the O.2S'mi|esduwnstveam(Photo l9B). TASK 5: MITIGATION OF EXISTING OR POTENTIAL PROBLEMS Anerosion and sedimentation control plan will bedesigned tnreduce the discharge ofsediment-laden runoff from the site. The plan will be comprised of temporary measures (rock entrance, filter fence, straw mulch, etc.) JOB #18-183 Technical Information Report 3m V, 3 �0 ^ 8ELLVVEATHERTO[}APARTMENTS aswell aspermanent measures (hydro seeding and bndscaping\. All ES[facilities will beperiodically inspected and maintained as necessary during construction to minimize impacts to the downstream system. Attached is email confirmation from the City of Tukwila regarding downstream drainage complaints for the project. Per the email, there are no downstream drainage issues that need to be addressed. mo#18-183 Technical Information Report 3.5 DOWNSTREAM DRAINAGE PATH (TYP.) PHOTO 1B, 5 152ND ST LUUYYII IITC/ IVl H1CCH GA 71Q11 PROPOSED DOWNSTREAM DRAINAGE PATH (B) PHOTO 4B 1 PHOTO 6B 1 PHOTO 28- PHOTO 38 SITE N¢T1A BOUNDARY -•. ... I PHOTO 123 B/PH0T0 PHOT010B /PH0l68 PHOTO18B PHOTO 78 138 L PHOTO 17B PHOTO 5BPHOTO 15B PHOTO B PHOTO14B PHOTO 9B PHOTO11B tam Creek (location per COT Surface Water 5DUTHCENTER BLVD, Comprehensive Plan, Figure 2) PHOTO 4AI\1111r1TM PHOTO 5A 1 0 1 \ PHOTO 6A r \ r PHOTO 7A N SCALE: 1" = 200' SO 110 BLUELINE m 0 m L JOB NUMBER. 18-183 FIGURE: DS James Reynes From: Jeff Heglund <Jeff.Heglund@TukwilaWA.gov> Sent: Wednesday, April 10, 2019 8:08 AM To: James Reynes; Ryan Larson Cc: Greg Villanueva; Gail Labanara Subject: Re: Downstream Drainage Complaints for 3481 S 152nd St. I spoke with my Foreman about this area and like Ryan said, other than the entire system being old and needing improvements, I don't have any complaints for this area. Jeff Heglund Tukwila Sewer& Surfacewater Maintenance Superintendent 600 Minkler Blvd. Tukwila, WA 98188 206-571-6312 (cell) 206-433-1864 (office) Jeffheglund@tukwilawa.gov The City of opportunity, the community of choice. From: James Reynes <jreynes@thebluelinegroup.com> Sent: Tuesday, April 9, 2019 2:12 PM To: Ryan Larson; Jeff Heglund Subject: RE: Downstream Drainage Complaints for 3481 S 152nd St. Hi Ryan and Jeff! I'm currently working on the TIR for the development on this site. Jeff, did you figure out if there are any additional downstream drainage complaints as described in the original email? Attached is the downstream drainage path for the proposed condition clouded in red. Thank you for your time! James C Reynes I ENGINEER BLUELINE THEBLUELINEGROUP.COM DIRECT 425.250.7254 ; MAIN 425.216.4051 From: Ryan Larson <Ryan.Larson@TukwilaWA.gov> Sent: Thursday, March 21, 2019 3:32 PM To: Jeff Heglund <Jeff.Heglund@TukwilaWA.gov> Cc: Greg Villanueva <Greg.Villanueva@TukwilaWA.gov>; James Reynes <jreynes@thebluelinegroup.com>; Gail Labanara <Gail.Labanara@TukwilaWA.gov> Subject: RE: Downstream Drainage Complaints for 3481 S 152nd St. 1 Please see the attached request regarding known drainage issues. Please let usknow ofany issues you or your crew isaware of|nthis vicinity. S. 152nd is on a CIP list for complete drainage improvements between TIB and 43"dAve. S. I am not aware of any specific deficiency other than the entire systern is old and needs improvements. Ryan LarsomPE. Jen/nrPrnoronnMunoger-Sur/ucoVkater 6300 Snud\centnrBlvd, Suite 20O Tukwila, VkA9B288-Z544 {206J'431-24S60*nrk) [206)S72'2668/ceDl 8von.LorsooP0Tukn///oW8.gov From: Gail Labanana<GaiLLabanara@Tukxv|aVVA.gov> Sent: Thursday, March 21'ZO192:5]PM To: Ryan Larson <Ryan.Lar'son@Tukwi1aWA.gov>; Greg Villanueva <Greg.Villanueva@TukwilaWA.gov> Subject: FW: Downstream Drainage Complaints for 3481 S 152nd St. Email just came in -thanks, g From: James Reynes <ireynesC@theb|ue|inegmup.com> Sent: Thursday, March 31'20l92:44PK4 To: Gail Labanara<GaU.Labanara@TukvvibVVA.gmv> Subject: Downstream Drainage Complaints for 3481 S 152nd St. To whomever it may concern, I hope this is the right person to reach out for the City of Tukwila regarding downstream drainage complaints. If you are not the right person, could you please email me the correct contact and I will discuss this further with them? Thank you smmuch for your time, | really appreciate it! I'm emailing you regarding downstream drainage complaints for the proposed storm drainage path that our new site plans todischarge to. VVeare working onanapartment project |ocatedat3481S1S3noStreet consisting of three parcels (00430]0108, 0043000112, and 0043000116). Attached is a quick downstream drainage exhibit I created showing the proposed drainage path that ultimately discharges into Gilliam Creek after traveling through the 42 u " Ave Sdetention pond. 2 ~ E, If you could let me know if there are any drainage complaints along that path,� that would be great. Please let nneknow /fyou need any additional infmrrnation!! Thanks again! James C0eynes|ENGINEER BLUEL|mE }/xsama'wEonoupzow CAUTION: This email originated frornoutaidethe[itvofTuhxvi|anetxxork.P|easeDO NOT open attachments orclick links from anunknown orsuspicious origin. CAUTION: This email originatedfronnoutsdathe[itvofTukxv|anetxvork.P|ease0O NOT open attachments orclick links from anunknown orsuspicious origin. 3 EXISTING DOWNSTREAM DRAINAGE PATH PHOTOGRAPHS • BELLWEATHER -OD APARTMENTS Photo 1— Facing south at the center of the site. Runoff sheet flows south towards the neighboring apartment complex. Photo 2 — Facing East in the parking lot of the neighboring apartment complex. Runoff is conveyed through the parking lot with an inverted crown roadway. Runoff travels east and then travels south towards Southcenter Boulevard. JOB #18-183 Technical Information Report 3.8 tor E BELLWEATHER TOD APARTMENTS Photo 3 — Facing southeast in the driveway of the neighboring apartment complex. Runoff is collected by the trench drain located in the existing driveway. Runoff is then conveyed southeast to a catch basin located in the middle of Southcenter Boulevard. Photo 4 — Facing southeast just south of Southcenter Boulevard. Runoff is conveyed south from the manhole in the middle of Southcenter Boulevard to a drainage ditch which conveys runoff southeast. JOB #18-183 Technical Information Report 3.9 BELLWEATHEF TOD APARTMENTS Photo 5 - Facing southeast on the west side of 3.9th Lane 5. Runoff is conveyed southeast through the ditch to an inlet. Photo 6 — Facing east just west of the intersection of 40th Avenue 5 and 39th Lane 5. Runoff is conveyed southeast to this manhole with a control structure. JOB #18-183 Technical Information Report 3.10 BELLWEATF- ER TOD APARTMENTS Photo 7— Facing south at the end of 40th Avenue S. Runoff is conveyed east where it outfalls to Gilliam Creek. This point is approximately %-miles from the site. JOB #18-183 Technical Information Report 3.11 BELLWEATHER TOD APARTMENTS PROPOSED DOWNSTREAM DRAINAGE PATH PHOTOGRAPHS Note: See the Downstream Drainage Exhibit for numbered locations of pictures. Photo 1— Facing east along the frontage of the site. Runoff is conveyed to a ditch and travels east through a culvert. Photo 2 — Facing east along the south side of 5 1.52^d Street. Runoff is conveyed east along S 152". JOB #18-183 Technical Information Report 3.12 BELLWEATHER TOD APARTMENTS Photo 3 — Facing east along the south side of S 152nd Street. Runoff is conveyed east along 5 152' Street. Photo 4 — Facing east along the south side of 5152nd Street. Runoff is corrveyed east along S 152nd Street. JOB #18-183 Technical Information Report 3.13 Wit 0 BELLWEATHER TOD APARTMENTS Photo 5— Facing east along the south side of S 1.52nd Street. Runoff is conveyed east along S 152Street. Photo 6— Facing east along the south side of S 152" Street. Runoff is conveyed east along S 152nd Street. JOB #18-183 Technical Information Report 3.14 mai lung MI BELLWEATHER TOD APARTMENTS Photo 7 — Facing east along the south side of S 152'd Street. Runoff is conveyed east along S 152nd Street. Photo 8 — Facing east along the south side of S 152^d Street. Runoff is conveyed east along 5 152'd Street. JOB #18-183 Technical Information Report 3.15 Oil IMO BELLWEATHER TOD APARTMENTS Photo 9 — Facing southeast at the southwest corner of S 152nd Street and 40Th Ave 5. Runoff is conveyed east approximately 5' to the catch basin on the same corner. Photo 10 — Facing east at the southwest corner of S 152nd Street and 40`h Avenue 5. Runoff is conveyed across 40°h Avenue South to a catch basin located on the south side of 5152^d Street. JOB #18-183 Technical Information Report 3.16 a NOVI INN BELLWEATI-ER TOD APARTMENTS Photo 11— Facing northeast on the south side of S 152"d Street. Runoff is conveyed northeast to a tight line system on the north side of 5152"d Street. Photo 12 — Facing east on the north side of S 152"d Street. Runoff is conveyed east towards the intersection of 5 152"d Street and 42"d Avenue 5. JOB #18-183 Technical Information Report 3.17 BELLWEATHER TOD APARTMENTS Photo 13 — Facing east on the north side of 5 152'd Street. Runoff is conveyed east into another catch basin. Photo 14— Facing east on the north side of S 152" Street. Flows continue east to the intersection of 42^d Ave 5 and 5 152'd Street. JOB #18-183 Technical Information Report 3.18 4, BELLWEATI-'ER TOD APARTMENTS Photo 15 — Facing east in the center of 42nd Avenue S. Runoff continues east in a tight line system. fr -• • I 4.44, 1r VI V vV,V Os Alte Photo 16— Facing east on the east side of 42nd Avenue S. Runoff continues east towards the 42nd Ave S Detention Pond. JOB #18-183 Technical Information Report 3.19 BELLWEATHER TOD APARTMENTS Photo 17— Facing north on the south side of the detention pond. Runoff is conveyed north to the detention pond. Photo 18— Facing northeast along the south side of the 42nd Avenue South Detention Pond. Storm wwater is conveyed and discharged east towards Gilliam Creek. JOB #18-183 Technical Information Report 3.20 BELLWEATHER TOD APARTMENTS Photo 19 — Facing east, east of the detention pond. Runoff discharges to Gilliam Creek at approximately the X-mile point downstream. JOB #18-183 Technical Information Report 3.21 BELLWEATHER TOD APARTMENTS Section 4 Developed Site Conditions In the developed condition, runoff will be collected, detained, and treated onsite before being pumped up to the public storm system in S 152"d Street, flowing east towards Gilliam Creek. Onsite runoff will be collected via a network of yard drains, catch basins, and pipes. This flow will then be treated for enhanced water quality with a BioPod system, then sent to a detention vault before being pumped to the northern frontage by force main. An area of 0.06-acres in the frontage will be collected and conveyed to the water quality and detention facilities. Approximately 0.03-ac of frontage will be bypassed, therefore, an in -lieu area of 0.03-ac of PGIS impervious surface will be conveyed to the on -site stormwater system to account for the bypassed area. Please see the Developed Conditions Exhibit in Section 1 of this report delineating areas tributary to the on -site stormwater system and the areas being bypassed. The drainage analysis was modeled using the Western Washington Hydrology Model (WWHM) software with 15-minute time steps in accordance with the 2016 KCSWDM. According to the Geotechnical Report by PanGEO, INC., onsite soils are predominantly till and will be modeled as such. The project lays within a region described by the Seatac rain gage with a scale factor of 1.0. EXISTING CONDITIONS The existing project basin boundary totals 1.38 acres. Consisting of three (3) parcels totaling to 1.29 acres with 0.09 acres of frontage improvements along S 152"d Street. The site contains four (4) existing single-family residences with carports, fencing, sheds, gravel driveways, trees, residential landscaping, and an access road which will all be removed prior to final stabilization. Onsite runoff is generated from one drainage basin. Onsite drainage generally sheet flows from the north to the south and enters a conveyance system that is tributary to the Gilliam Creek drainage basin. Please see the Existing Conditions Exhibit in Section 1 of this report. The site lies within a Level 2 Flow Control Area which dictates that the existing condition be modeled in the historic (forested) conditions. The areas used to compute the drainage calculations associated with the existing basin conditions, as well as the corresponding WWHM output, are summarized on the following pages of this report. 0 JOB #18-183 Technical Information Report 4.1 IOW ail r. r w w Ian Osor EXISTING CONDITIONS Impervious Pervious BELLWEATHER TOD APARTMENTS Upstream Impervious Area 0.01 ac Total Impervious 0.01 ac On -site Area Frontage Area Total Pervious Total Existing Conditions 1.29 ac 0.09 ac 1.38 Ac 1.39 ac Flow Frequency Return Periods for Predeveloped. Basin POC 1 Return Period Flow(cfs) 2 year 0.0409 5 year 0.0642 10 year 0.0774 25 year 0.0914 50 year 0.1001 100 year 0.1074 DEVELOPED CONDITIONS Drainage from the developed site will be collected, detained, and treated onsite before being pumped up to the public storm system in S 152nd Street which conveys runoff east towards Gilliam Creek. Onsite runoff will be collected via a network of yard drains, catch basins, and pipes treated for enhanced water quality with a modular wetland system and then a detention vault before being conveyed to the northern frontage. An area of 0.06-acres in the frontage will be collected and conveyed to the water quality and detention facilities. Approximately 0.03-ac of frontage will be bypassed, therefore, an additional in -lieu area of 0.03-ac of PGIS impervious surface will be conveyed to the on -site stormwater system to account for the bypassed area. The developed basin, 1.38 acres, consists of both on -site and frontage pervious and impervious areas. The areas used to compute the drainage calculations associated with the developed basin conditions, as well as the corresponding WWHM output, are summarized below and on the following pages of this report. JOB #18-183 Technical Information Report 4.2 «NW DEVELOPED CONDITIONS Vault Tributary Impervious Pervious Bypass Impervious Pervious BELLWEATHER TOD APARTMENTS On -site Area 1.02 ac Frontage Non-PGIS Area 0.04 ac Frontage PGIS Area 0.02 ac Frontage In -Lieu PGIS Area 0.03 ac Upstream PGIS Area 0.01 ac Total Impervious 1.12 ac On -site Area 0.27 ac Frontage Area 0.00 ac Total Pervious (Soil Group C - Till) 0.27 ac Frontage Non-PGIS Area 0.00 ac Frontage PGIS Area 0.02 ac Frontage In -Lieu PGIS Area (0.02) ac Total Impervious 0 ac Frontage Area Frontage In -Lieu Area Total Pervious (Soil Group C —Till) Total Developed Conditions 0.00 ac (0.00) ac 0 ac 1.39 ac Flow Frequency Return Periods for Developed. Basin POC #1 Return Period Flow(cfs) 2 year 0.0262 5 year 0.0417 10 year 0.0545 25 year 0.0741 50 year 0.0913 100 year 0.1111 JOB #18-183 Technical Information Report 4.3 mai iv* WM IMO INV 41. BELLWEATHER TOD APARTMENTS 4.1 FLOW CONTROL ANALYSIS AND DESIGN The flow control system was designed in compliance with the 2016 KCSWDM. A detention vault and control structure will be located on the southern portion of the site. The outlet control structure will release runoff at rates that match the level 2 flow criteria of 50% of the 2-year peak flow to the 50-year peak flow. The detained and treated flows will discharge to the proposed tight -lined system where they are pumped up to a catch basin installed near the northern parcel boundary line, close to the S 152"d Street frontage. All onsite stormwater will be collected and conveyed to the detention facility prior to offsite discharge. Frontage areas totaling to 0.09 acres will be conveyed on -site to the vault and will be modelled as such. Per the WWHM printout provided below, the live storage volume required at the maximum stage of 7.0' is 25,725 cubic feet. The provided vault volume will exceed the minimum required. The proposed vault will provide 2 — 15' x 128' x 7' live storage cells, totaling to 26,880 cubic feet. The proposed vault is therefore, adequately sized for the required flow control. Live Storage Volume Required = 25,725 cubic feet Provided = 26,880 cubic feet JOB #18-183 Technical Information Report 4.4 BELLWEATHER TOD ADARTMENTS WWHM2012 PROJECT REPORT Project Name: Bellweather Site Name: Site Address: City Report Date: 9/17/2019 Gage : Seatac Data Start : 1948/10/01 Data End : 2009/09/30 Precip Scale: 1.00 Version Date: 2018/10/10 Version : 4.2.16 Low Flow Threshold for POC 1 : 50 Percent of the 2 Year High Flow Threshold for POC 1: 50 year PREDEVELOPED LAND USE Name : Basin Bypass: No GroundWater: No Pervious Land Use a C, Forest, Flat 1.29 Pervious Total 1.29 Impervious Land Use acre Impervious Total 0 Basin Total 1.29 Element Flows To: Surface Interflow Groundwater Name : Basin 2 Bypass: No GroundWater: No JOB #18-183 Technical Information Report 4.5 pr is• rot BELLWEATHER TOD APARTMENTS Pervious Land Use C, Forest, Flat acre .1 Pervious Total 0.1 Impervious Land Use acre Impervious Total 0 Basin Total 0.1 Element Flows To: Surface Interflow Groundwater MITIGATED LAND USE Name : Basin I Bypass: No GroundWater: No Pervious Land Use C, Lawn, Flat Pervious Total Impervious Land Use ROADS FLAT Impervious Total Basin Total acre .14 0.14 acre 1.15 1.15 1.29 Element Flows To: Surface Interflow Vault 1 Vault 1 Groundwater Name : Basin 2 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat .02 JOB #18-183 Technical Information Report 4.6 100 Pervious Total 0.02 Impervious Land Use acre ROADS FLAT 0.07 DRIVEWAYS FLAT 0.01 Impervious Total 0.08 Basin Total 0.1 BELLWEATHER TOD APARTMENTS Element Flows To: Surface Interflow Vault 1 Vault 1 Groundwater Name : Vault 1 Width : Length : Depth: 30 ft. 122.5 ft. 8 ft. Discharge Structure Riser Height: 7 ft. Riser Diameter: 12 in. Orifice 1 Diameter: 0.625 in. Elevation: 0 Orifice 2 Diameter: 1.0625 in. Elevation: 4.4 ft. Element Flows To: Outlet 1 Outlet 2 Vault Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft,) Discharge(cfs) Infilt(cfs) 0.0000 0.084 0.000 0.000 0.000 0.0889 0.084 0.007 0.003 0.000 0.1778 0.084 0.015 0.004 0.000 0.2667 0.084 0.022 0.005 0.000 0.3556 0.084 0.030 0.006 0.000 0.4444 0.084 0.037 0.007 0.000 0.5333 0.084 0.045 0.007 0.000 0.6222 0.084 0.052 0.008 0.000 0.7111 0.084 0.060 0.008 0.000 0.8000 0.084 0.067 0.009 0.000 0.8889 0.084 0.075 0.010 0.000 0.9778 0.084 0.082 0.010 0.000 1.0667 0.084 0.090 0.010 0.000 1.1556 0.084 0.097 0.011 0.000 1.2444 0.084 0.105 0.011 0.000 1.3333 0.084 0.112 0.012 0.000 JOB #18-183 Technical Information Report 4.7 BELLVVEATHERTC)DAPARTMENTS 1.4222 0'084 0.120 0.0I2 O'OOU I,5I1I 0.084 0.127 0.013 0.000 1.6000 0'084 0.I35 0.0I3 0.000 1,6889 0.084 0'I42 0.0I3 0.000 1.7778 0'084 0.150 0'0I4 0,000 1.8667 0.084 0'I57 0,0I4 0.000 1.9556 0.084 0'I65 0'014 0'000 2.0444 0.084 0.172 0.015 0.000 2.I333 0.084 0.I80 0.0I5 0.000 2.2222 0,084 0'187 0.015 0.000 2.3II1 0,084 0'I95 0.0I6 0.000 2,4000 0'084 0'202 0.0I6 0.000 2.4889 0,084 0'2I0 0.0I6 0.000 2.5778 0.084 0'2I7 0.0I7 0.000 2.5667 0.084 0'225 0.017 0.000 2.7556 0.084 0'232 0'017 0.000 2.8444 0'084 0.240 0.017 0.000 2.9333 0'084 0.247 0.0I8 0.000 3.0222 0.084 0.255 0.018 0'000 3,III1 0'084 0'262 0.018 0'000 3'2000 0'084 0.270 0.0I9 0.000 3.2889 0.084 0'277 0.019 0.000 3.3778 0.084 0.285 0.019 0.000 3.4667 0.084 0.292 0.0I9 0.000 3'5556 0'084 0.300 0.020 0.000 3'6444 0'084 0'307 0.020 0.000 3.73]] 0.084 0'315 0.020 0'000 3.8222 0.084 0.322 0.020 0'000 3.9II1 0.084 0'330 0.02I 0.000 4.0000 0.084 0.337 0.02I 0.000 4.0889 0.084 0.345 0.02I 0.000 4.I776 0.084 0.352 0.02I 0'000 4.2667 0'084 0'360 0.021 0'000 4.3556 0.084 0'367 0.022 0.000 1'4444 0.084 0.375 0.028 0.000 4.55]} 0.084 0.382 0.035 0.000 4.6222 0.084 0.390 0.037 0.000 4.7I11 0.084 0.397 0.040 0.000 4.8000 0.084 0'405 0.042 0.0130 4.8889 0.084 0.4I2 0.044 0.000 4.9778 0.084 0'420 0'046 0.000 5.0667 0.084 0'427 0.048 0'000 5.1556 0.084 0.435 0.050 0.000 5.2444 0.084 0.442 0.052 0.000 5.3333 0.084 0.450 0.054 0.000 5.4222 0.084 0.457 0,055 0.000 5.5111 0'084 0.465 0.057 0'000 5.6000 0'084 0'472 0.058 0.000 5.6889 0.084 0'480 0.060 0'000 5.7776 0.084 0'487 O.O«l 0.000 5.8667 0.084 0'494 0.062 0.000 5.9556 0.084 0.502 0.064 0.000 6.0444 0.08* 0.509 0.065 0.000 6.I333 0.084 0.517 0.066 0.000 6.2222 0.084 0.524 0.067 0.000 JOB 0$18-183 Technical Information Report 4.8 BELLVVEATHEF<TQOA:'ARTK8ENT8 6,3I11 0.084 0'532 0.069 0.000 6.4000 0'084 0,539 0.070 0.000 6'4889 0'084 0.547 0.07I 0.000 6'5778 0.084 0.554 0.072 0.000 6.6667 0.084 0'562 0.073 0.000 6.7556 0.084 0'569 0.074 0.000 6.8444 0'084 0'577 0.075 0.000 6.9]3] 0.084 0.584 0.076 0.000 7.0222 0.084 0'592 0.112 0'000 7,1111 0'084 0'599 0.450 0-000 7.2000 0'084 0'607 0.987 0.000 7.2889 0'084 0.614 1.528 0.080 7.3778 0'084 0,622 I'960 0.000 7.4667 0.084 0.629 2'220 0.000 7.5556 0.084 0,637 2.431 0'000 7.6444 0.084 0,644 2.612 0.000 7.7333 0'084 0'652 2.782 0.000 7.8222 0'084 0'659 2.942 0.000 7.9111 0'084 0.667 3.093 0.000 8,0000 0'084 0.674 3.237 0.000 8.0889 0.084 0.682 3.375 O'OOO 8.1778 0.000 0'000 3'508 0.000 xmvALrnzo R000Lro Stream Protection Duration Predeveloped Lapdume Totals for sOC #1 Total Pervious urea:1.39 Total Impervious Axea:0 Mitigated Laouuwe Totals for roC #z Total Pervious xuea,0.16 Total Impervious Area:1'23 Flow Frequency Return Periods for eredeveloped. mOvz #z Return Period nzo*(ofa) 2 year 0'040867 5 year 0.064183 10 year 0.077397 25 year 0.091395 50 year 0.I00058 100 year 0.I07426 Flow Frequency Return Periods for Mitigated' sOo #1 Return Period rzow(ofa) o year 0'026153 5 year 0'041658 JOB #18-oo Technical Information Repor-t 4.9 w � � � N� � BEL0VEATMERTO[]APARTMENTS 0.054509 O'O7407I 0.09131 O'IIIO59 Stream Protection Duration Annual Peaks for nradevelppod and Mitigated' sOo #1 Year gredevslopmd Mitigated I949 0.040 8.0I8 I950 0'050 0.022 1951 0'090 0.067 1952 0.028 0.0I6 1953 0.023 0.021 1954 0.035 0'019 1955 0'056 0,019 I956 0'045 0'049 1957 0.036 0.0I9 1958 0'041 0,02I 1959 0.035 0,0I8 I960 0'061 0.056 I961 0'034 0.031 1962 0.02I 0'0I7 1963 0'029 0.021 1964 0.039 0.026 1965 0'028 0'040 1966 0.027 0'020 1967 0'056 0.022 1968 0'035 U'DaV 1969 0.034 0.019 1970 0,028 0'021 197I 0'030 0.021 1972 0'067 0.059 1973 0'030 0'038 1974 0'033 0.020 1975 0.045 0'0I9 1976 0'032 0,020 1977 0.004 0.0I7 1978 0'028 0,02I 1979 0.017 0.0I5 1980 0.064 0.060 198I 0'025 0.020 1982 0'049 0.051 1983 0.044 0.020 I984 0'027 0.017 1985 0.0I6 0.018 1986 0.07I 0.022 1987 0'063 0.054 1988 0.025 0'0I9 1989 0'0I6 0'0I8 I990 0.I3I 0.057 I991 0.079 0.059 1992 0'030 0.021 1995 0.032 0.017 1994 0'0I1 0'015 mm#18-183 Technical Information Report «lQ BELLVVEATHERTCJ[)APARTMENTS 1995 0'045 O.O]l 1996 0.096 0'064 1997 0,000 0'063 1998 0'018 0.017 1999 0.075 0'059 2000 0'032 0'022 200I 0'006 0.014 2002 0,035 0.032 2003 0.044 0'019 2004 0'057 0.068 2005 0.04I 0.0I9 2006 0'048 0.046 2007 0,097 0,098 2008 0.125 0.062 2009 0.062 0'04I Stream Protection Duration Ranked Annual Peaks for Prodaveloped and Mitigated. PoC #1 Rank ereuevelpIed Mitigated I 0'I3I0 0.0982 2 0.1254 0.0685 ] 0.0972 0.0668 4 0.0958 0'064I 5 0,0900 0'063I 6 0.0800 0.06I8 7 0.0789 0'0596 8 0.075I 0'0587 9 0.0708 0'0585 IU 0'0670 0.0585 II 0.0635 0.0566 12 0'0627 0.0565 I] 0.06I6 0'0538 14 0.0609 0.05I0 15 0.0572 0'0486 16 0'0562 0.0465 17 0.0556 0'0406 18 0'050I 0.0403 19 0'0488 0'0381 20 0'0484 0.0319 21 0.0*54 0'0314 22 0.0448 0.0306 23 0.0447 0.0257 24 0.0*42 0.02I9 25 0.0438 0.02I6 26 0.0410 0.02I7 27 0.0406 0'0216 28 0'040I 0'02I4 29 0.0386 0'02I4 30 0.036I 0.0213 31 0.0352 0.0208 32 0.0549 0'0207 33 0'0347 0.0205 34 0.0346 0.0205 35 0.8343 0.0200 xOmw1n-1au Technical Information Report 4�zz im r� opt 36 0.0339 37 0.0330 38 O.O]24 39 0.0317 40 O'O3I6 41 0.0304 42 O'O3O4 4] 0.0299 44 O'O29] 45 0.0284 46 0.0284 47 0.0280 48 0.0276 49 0.0270 50 0.0266 51 O'O254 52 0.0247 53 0.0229 54 0.0214 55 0.0181 56 0.0172 57 0.0161 58 0.0160 59 0.0106 60 0.0057 61 0.0039 0.0200 0.0199 O'Ol99 O'Ul98 0.0197 0.0194 0.0193 O'0l92 0,0192 O'0l92 0.0190 0.0189 0.0186 0.0185 0.0181 0.0176 0.0175 0.0174 0.0167 0.0167 0'OI66 0.0165 0.0163 0.0153 0.0149 0.0143 BELLVVEATHERT{}OAPARTMENTS Stream Protection Duration eqo #1 The Facility gxu;oEo The Facility PASSED. Flow (ofa) 0'0204 0.0212 0.0220 0.0228 U.02]7 0.0245 O'O253 0,0261 0.0269 0,0277 0.0285 0,0293 0,0301 0.0309 0.0317 0.0325 0.O3]3 0.0341 0.0349 0'O357 ereuev 17556 16170 14966 13856 12810 11813 10904 10121 9386 87]I 8147 7593 7060 6592 6147 5781 5431 5101. 4808 4526 Mit Percentage Pass/Fail 17458 99 Pass lll§I 69 Pass 6532 43 Pass 5961 43 paoe 5809 45 Pass 5672 40 pass 5529 50 Pans 5384 53 pass 5243 55 Paaa 5118 58 Pass 4984 GI Pass 4949 63 2ano 4686 66 Pass 1554 69 Pass 4393 71 Pass 4282 74 Pass 4182 77 eana 4079 79 Pass 3921 81 Pass 3797 83 Pass /oe#zu183 Technical Information Report 4.12 BELLWEATHER TOD A'ARTMENTS 0.0365 4254 3692 86 Pass 0.0373 4017 3570 88 Pass 0.0381 3784 3414 90 Pass 0.0389 3546 3283 92 Pass 0.0397 3339 3140 94 Pass 0.0405 3138 2967 94 Pass 0.0413 2952 2860 96 Pass 0.0421 2787 2766 99 Pass 0.0430 2599 2648 101 Pass 0.0438 2449 2526 103 Pass 0.0446 2304 2415 104 Pass 0.0454 2162 2297 106 Pass 0.0462 2024 2184 107 Pass 0.0470 1898 2047 107 Pass 0.0478 1790 1885 105 Pass 0.0486 1687 1754 103 Pass 0.0494 1586 1638 103 Pass 0.0502 1483 1548 104 Pass 0.0510 1380 L458 105 Pass 0.0518 1292 1366 105 Pass 0.0526 1219 1271 104 Pass 0.0534 1155 1174 101 Pass 0.0542 1098 1089 99 Pass 0.0550 1048 1000 95 Pass 0.0558 997 904 90 Pass 0.0566 930 774 83 Pass 0.0574 883 687 77 Pass 0.0582 837 603 72 Pass 0.0590 789 508 64 Pass 0.0598 743 424 57 Pass 0.0606 713 388 54 Pass 0.0615 668 350 52 Pass 0.0623 630 315 50 Pass 0.0631 595 282 47 Pass 0.0639 565 253 44 Pass 0.0647 539 229 42 Pass 0.0655 496 212 42 Pass 0.0663 473 187 39 Pass 0.0671 434 157 36 Pass 0.0679 399 139 34 Pass 0.0687 366 121 33 Pass 0.0695 348 117 33 Pass 0.0703 323 112 34 Pass 0.0711 296 106 35 Pass 0.0719 272 100 36 Pass 0.0727 256 80 31 Pass 0.0735 235 62 26 Pass 0.0743 217 52 23 Pass 0.0751 195 43 22 Pass 0.0759 180 35 19 Pass 0.0767 158 19 12 Pass 0.0775 145 18 12 Pass 0.0783 129 18 13 Pass 0.0791 119 16 13 Pass 0.0800 109 16 14 Pass JOB #18-183 Technical Information Report 4.13 awl uoul r.r Oa ar r 1q • vz sir BELLWEATHER TOD APARTMENTS 0.0808 97 16 16 Pass 0.0816 91 16 17 Pass 0.0824 82 16 19 Pass 0.0832 76 15 19 Pass 0.0840 69 15 21 Pass 0.0848 61 14 22 Pass 0.0856 54 14 25 Pass 0.0864 48 13 27 Pass 0.0872 41 13 31 Pass 0.0880 38 13 34 Pass 0.0888 33 12 36 Pass 0.0896 27 12 44 Pass 0.0904 22 11 50 Pass 0.0912 21 11 52 Pass 0.0920 20 10 50 Pass 0.0928 19 8 42 Pass 0.0936 17 7 41 Pass 0.0944 14 6 42 Pass 0.0952 12 6 50 Pass 0.0960 8 5 62 Pass 0.0968 4 3 75 Pass 0.0976 3 2 66 Pass 0.0984 3 0 0 Pass 0.0993 3 0 0 Pass 0.1001 3 0 0 Pass Water Quality BMP Flow and Volume for POC #1 On-line facility volume: 0 acre-feet On-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs, Off-line facility target flow: 0 cfs. Adjusted for 15 min: 0 cfs. LID Report LID Technique Used for Total Volume Volume Infiltration Cumulative Percent Water Quality Percent Comment Treatment? Needs Through Volume Volume volume Water Quality Treatment Facility (ac-ft.) Infiltration Infiltrated Treated (ac-ft) (ac-ft) Credit Vault 1 POC N 187.43 N 0.00 Total Volume Infiltrated 187.43 0.00 0.00 0.00 0.00 0% No Treat. Credit Compliance with LID Standard 8 Duration Analysis Result = Failed Perind and Impind Changes No changes have been made. JOB #18-183 Technical Information Report 4.14 BELLWEATHER TOD APARTMENTS This program and accompanying documentation are provided 'as-iswithout warranty of any kind. The entire risk regarding the performance and results of this program is assumed by End User. Clear Creek Solutions Inc. and the governmental licensee or sublicensees disclaim all warranties, either expressed or implied, including but not limited to implied warranties of program and accompanying documentation. In no event shall Clear Creek Solutions Inc. be liable for any damages whatsoever (including without limitation to damages for loss of business profits, loss of business information, business interruption, and the like) arising out of the use of, or inability to use this program even if Clear Creek Solutions Inc. or their authorized representatives have been advised of the possibility of such damages. Software Copyright © by : Clear Creek Solutions, Inc. 2005-2019; All Rights Reserved. JOB #18-183 Technical Information Report 4.15 E� ~ . BELLVVEATHERTCJ[}APARTMENTS 4'2 WATER QUALITY SYSTEM The project will create over 5,000 sf of Pollution Generating Impervious Surfaces (PGIS), requiring the project tm install water quality treatment facilities. Water quality treatment will be provided per the Enhanced Quality Treatment Menu with a BioPod system to be located at the southern end of the parking lot prior to discharging into the detention vault. The 0oPodissized to treat the flow for 91%ofthe total runoff ofthe basin will beused asthe basis for design. This value was calculated using WWHM software, with outputs summarized below. Per the 2016 KCSWDM Table 6.2.1.A, this flow rate must be adjusted with a k-factor when calculated using modeled on-line/off-line rates. The k-factorbcalculated utilizing the 2-year,24-hourprecipitation depth determined by the8]16 KCSWUM Isopluvial maps and the equations given in Table 6.2.1.A. The inputs for design and the WWHIVI output are included onthe following pages. &I P_ °.. a.-FAV SWXI�d=~~@�J|'A�,"d Flm~tewb 0369� U o ~°�°|m~ /*�]��/*_'""'F�FbW°=V"t* 7 LV P--Tm 10 17B Water Quality Summary Table Tributary Area (ac) WWHIVI WNQFlow'Rate 2-year, 24'hourPrecipitatlmn Adjustment Factor "h° Water Quality Flow tmFacility 0.S7ac D.0656cfs. 2.0in 1.9] Jno#zuaoa Technical Information Report 4.16 BELLWEATHER TOD APARTMENTS :h Ft. TWIN 12 RI_NOVF COMPLITATKIN ANT'sl 'CI'. NWT( FIGURE 3.2.I.A 2-YEAR 244IOUR ISOPLUVIALS SITE: 2.0IN. 72% of 2-year, 24-hour = 1.44 IN. WESTERN KING COUNTY 2-Year 24-Hour Precipitation In Inches *airlift 14110 *Ibliarrit TABLE 6.2.1.A AOJUSTWENT FACTOR* FOR CALCULATING' MODIFIED WATER OLALITV FLOW RATE FROM MODELED ON-LLNE‘OFT-LLNE RATES ___„ -• MIR Peak/WWHM CM-I.Ine 15-min WQ Flow Ratio vs 6-rnonth Precipitation for O% to 100% Impervious Areas $13W4 Peak/WWHIM Off -Line 15-min WQ Flow Ratio vs 6-month Precipitation lor 0% to 100% Impervio' us Areas 6-manth, 24-hr 6-month, 20-hr precipitation (72% of the 2-yr), inches Ratio, k precipitation (72% of the 2 . vrh tricheS Ratio, k 0.80 1 01 0.80 1.95 1.00 1.30 1.00 2,44 1 50 2.02 1,50 3.68 2.00 2.74 2.00 4.92 2.50 3 45 2.50 6 16 2.90 4 03 2.90 7,15 inrermediote Kauof k for WWHM a e calculated by linear interpolation SOUR; PeakThIGSFlood Onaline and Offline 1S•min WQ Flow Ratio vs 6,-morith Precipitation for 0% to 100% Impervious Areas For on-line facilities k = 1. 41 (P77%, .2-vr ) - 0 052 (Fq 6-11 For off-line facilities: k . 2.50 (P72%, 2-yr.) - 0.052 (Eq. 6-2I where. P72%, 2,yr = 12% of the 2-year, 24- hour precipitation depth lin.) Rote: If trte 6-month. 24-hour precipitation depth (in ) is known for the project site; that value may be used instead of P72%, 2 yr alaaalraalWari JOB #18-183 Technical Information Report 4.17 RIM:322.27' 6,48' [77,76"1 BPU-4121B WADOE GULD Treatment Flow Capacity 64.0 gpm 10.143 cfs BYPASS WEIR EL:318.96' DIVIDER WALL 3.98' [47.761 IE:318,29' INLET, 018.00" OPENING FOR 012,00" HOPE, 4'x12"INLET WINDOW, EL:318.48' DRAIN DOWN DEVICE 50` 4 0` 1X 018.00" TRAFFIC RATED CAST IRON GRATE, FIELD POURED CONCRETE COLLAR REQUIRED, BY OTHERS. SECTION D•D INLET, 01800" OPENING FOR 0121" HDPE, IE:318,29', DRAIN DOWN DEVICE BYPASS WEIR, 1'4EL:318.96' 2'-0" OUTLET, 018.00'x29.00" OBROUND OPENING FOR 012.00" HDPE, IE: 316.29', 1X 018.00" TRAFFIC RATED CAST IRON COVER, FIELD POURED CONCRETE COLLAR REQUIRED, BY OTHERS. RIM: 322.21' �D 1'-0" 4334" ADJUST TO GRADE 120" 9",6N MEDIA AREA 4"x12" INLET WINDOW, EL: 318.46' COBBLES FOR ENERGY DISSIPATION DIVIDER WALL 04,00" HDPE OUTLET ORIFICE CAP INTO OUTLET CHAMBER PLAN VIEW DRAIN DOWN DEVICE r- DIVIDER WALL 6° TYPICAL ALL THICKNESS .00" SLOTTED HDPE UNDERDRAIN TOP SLAB NOT SHOWN IN THIS VIEW FOR CLARITY. GRATE & COVERS SHOWN IN PHANTOM. NOTES DESIGN LOADINGS: A. AASHTO HS 3044 WI IMPACT. 0. DESIGN FILL: I'MAXIMUM. C. ASSUMED WATER TABLE 4 S' BEL0W GRADE. 0. DRY LATERAL EARTH PRESSURE (FFPI=40 PCF. E. LATERAILIVE LOAD SURCHARGE =80PSF (APPLIED TO B' BELOWGRADE) F. NO LATERAL SURCHARGE FROM ADJACENT BUILDINGS, WALLS, PIERS, OR FOUNDATIONS. 2. CONCRETE 28 DAY COMPRESSIVE STRENGTH SHALL BE S,WO PSI MINIMUM 3. STEEL REINFORCEMENT: REBAR.ASTMA-6130R A.106,GRADE 60. 4. MESH REINFORCEMENT:ASTMA1064,S12.GRADE 80. S. CEMENT. APO CAR SPECIFICATION. 6, REFERENCE STANDARD. A. ASTMCB90 B. AVM C913 1. THIS STRUCTURE IS DESIGNED TO THE PARAMETERS NOTED HEREIN, PLEASE VERIFY TNAT THESE PARAMETERS MEET PROJECT REQUIREMENTS (LEE. LIVE LOAD, FILL RANGE, WATER TABLE) 14 DESIGN PARAMETERS ARE INCORRECT, REVIEIMNG ENGINEER/AUTHORITY SHALL. NOTIFY OLOOASTLE INFRASTRUCTURE UPON REVIEWOF THIS SUBMITTAL 6, OVERSIZED HOLES TO ACCOMMODATE SPECIFIC PIPE TYPE MUST BE CONCENTRIC TO PIPE ID. AFTER PIPES ARE INSTALLED, ALL ANNULAR SPACES SHALL BE FILLED NITHA MINIMUM OF 3000 PSI CONCRETE FOR FULL THICKNESS OF PRECAST WALLS. 9. CONTRACTOR RESPONSIBLE TO VERIFY ALL SIZES, LOCATIONS AND ELEVATIONS OF OPENINGS, 10, CONTRACTOR RESPONSIBLE TO ENSURE ADEQUATE BEARING SURFACE IS PROVIDED (I.E. COMPACTED AND LEVEL PER PROJECT SPECIFICATIONS;. 11, ADAPTORSIANGLES AND EXTERNAL PIPING B3 OTHERS. 1X 036.00' BOLTED 8 GASKETED ACCESS COVER, FIELD POURED CONCRETE COLLAR REQUIRED, 12 MAYJMUMPICK 1NEIDn:BASE CHARGED ITN BY OTHERS. ROCK 8 MEDNd6,600 LBS. 11' SLAB 5.98' 171 761 ANTI SKID JOINT BYPASS WEIR EL: 318.96' IE: 316,29' OUTLET, 018.00"x29.00" ' OBROUND OPENING FOR 012.00' HDPE, NEARSIDE. 04.00" HDPE OUTLET ORIFICE CAP INTO OUTLET CHAMBER, REV DESCRIPTION BY F DATE 2'4i"r OUTLET, 018.00"x29.00' OBROUND OPENING FOR 012,00" HDPE, INLET, 018.00" OPENING — FOR 012,00" HDPE, IE: 318,29', FARSIDE, —COBBLES FOR ENERGY DISSIPATION 4"x12" INLET WINDOW, EL: 318.46' SECTION A•A 2" MULCH 4'•8" 1 40 1'•6" StormMix MEDIA 6" DRAIN ROCK 6" 04,00" SLOTTED HDPE UNDERDRAIN - PRELIMINARY - NOT FOR CONSTRUCTION � 0Idcastie Infrastructure° MOONY B(d4918I8I..olka iMontres larm. MIS DOCUMENE [PIE PROPERtl OF DLOCASRE INFRAStRUC1URE INC. IT 19 CONFIDENTIAL SUBMITTED FOR REFERENCE PURPOSES ONLY ANO SNAIL NOT BE USED IN ANYWAY INJURIOUS TOTHE INTERESTS OF, OR WITNOUT THE MITTEN PERMISSIM OF OICCASTLE INFRASTRUCTURE, IHC. COPYRGMT G:OLROLCCASREINFRASTRIX URE INC MSRWNfe MEMO BioPodTM Biollter System Underground Vaull Wth Internal Bypass CUSTOMER Blueline AMti+wE Bellweather • Tukwila WA 4rE 944119 MN, 4RUN 010-AU PPS AwfPN4... MD EMiMEER MIT cam MJT SRIL P404R PDD•10139 CVO NLVWTL SIR DF 1 WS6T STATE DEE PcA ioT GLOOyF July 2018 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), DISSOLVED METALS (ENHANCED), AND PHOSPHORUS TREATMENT For Oldcastle Infrastructure, Inc.'s The BioPodTM Biofilter (Formerly the TreePod Biofilter) Ecology's Decision: Based on Oldcastle Infrastructure, Inc. application submissions for the The BioPodTM Biofilter (BioPod), Ecology hereby issues the following use level designation: 1. General Use Level Designation (GULD) for Basic, Enhanced, and Phosphorus Treatment: • Sized at a hydraulic loading rate of 1.6 gallons per minute (gpm) per square foot (sq ft) of media surface area. 2. Ecology approves the BioPod at the hydraulic loading rate listed above, to achieve the maximum water quality design flow rate. The water quality design flow rates are calculated using the following procedures: • Western Washington: For treatment installed upstream of detention or retention, the water quality design flow rate is the peak 15-minute flow rate as. calculated using the latest version of the Western Washington Hydrology Model or other Ecology - approved continuous runoff model. • Eastern Washington: For treatment installed upstream of detentiou or retention, the water quality design flow rate is the peak 15-minute flow rate as calculated using one of the three methods described in Chapter 2.2.5 of the Stormwater Management Manual for Eastern Washington (SWMMEW) or local manual. • Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 3. The GULD has no expiration date, but may be amended or revoked by Ecology. • Ecology's Conditions of Use: The BioPod shall comply with these conditions: 1) Oldcastle Infrastructure, Inc. shall design, assemble, install, operate, and maintain the BioPod installations in accordance with Oldcastle Infrastructure, Inc.'s applicable manuals and the Ecology Decision. 2) BioPod media shall conform to the specifications submitted to and approved by Ecology 3) Maintenance: The required inspection/maintenance interval for stormwater treatment devices is often dependent on the efficiency of the device and the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a "one size fits all" maintenance cycle for a particular model/size of manufactured filter treatment device. • The BioPod is designed for a target maintenance interval of 1 year. Maintenance includes replacing the mulch, assessing plant health, removal of trash, and raking the top few inches of engineered media. • A BioPod system tested at the Lake Union Ship Canal Test Facility in Seattle, WA required maintenance after 1.5 months, or 6.3% of a water year. Monitoring personnel observed similar maintenance issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may be unusual and maintenance requirements of systems installed at the Test Facility may not be indicative of maintenance requirements for all sites. • Test results provided to Ecology from a BioPod System evaluated in a lab following New Jersey Department of Environmental Protection Laboratory Protocol for Filtration MTDs have indicated the BioPod System is capable of longer maintenance intervals. • Owners/operators must inspect BioPod systems for a minimum of twelve months from the start of post -construction operation to determine site -specific inspection/maintenance schedules and requirements. Owners/operators must conduct inspections monthly during the wet season, and every other month during the dry season. (According to the SWMMWW, the wet season in western Washington is October 1 to April 30. According to the SWMMEW, the wet season in eastern Washington is October 1 to June 30.) After the first year of operation, owners/operators must conduct inspections based on the findings during the first year of inspections. • Conduct inspections by qualified personnel, follow manufacturer's guidelines, and use methods capable of determining either a decrease in treated effluent flow rate and/or a decrease in pollutant removal ability. 4) Install the BioPod in such a manner that you bypass flows exceeding the maximum operating rate and you will not resuspend captured sediment. 111 5) Discharges from the BioPod shall not cause or contribute to water quality standards violations in receiving waters. Applicant: Oldcastle Infrastructure, Inc. Applicant's Address: 360 Sutton Place Santa Rosa, CA 95407 Application Documents: Technical Evaluation Report TreePodTM BioFilter System Performance Certification Project, Prepared for Oldcastle, Inc., Prepared by Herrera Environmental Consultants, Inc. February 2018 Technical Memorandum: Response to Board of External Reviewers' Comments on the Technical Evaluation Report for the TreePodTM Biofilter System Performance Certification Project, Oldcastle, Inc. and Herrera Environmental Consultants, Inc., February 2018 Technical Memorandum: Response to Board of External Reviewers' Comments on the Technical Evaluation Report for the TreePodTM Biofilter System Performance Certification Project, Oldcastle, Inc. and Herrera Environmental Consultants, Inc., January 2018 Application for Pilot Use Level Designation, TreePodTM Biofilter — Stormwater Treatment System, Oldcastle Stormwater Solutions, May 2016 Emerging Stormwater Treatment Technologies Application for Certification: The TreePodT Biofilter, Oldcastle Stormwater Solutions, April 2016 Applicant's Use Level Request: • General Use Level Designation as a Basic, Enhanced, and Phosphorus Treatment device in accordance with Ecology's Stormwater Management Manual for Western Washington Applicant's Performance Claims: Based on results from laboratory and field-testing, the applicant claims the BioPodTM Biofilter operating at a hydraulic loading rate of 153 inches per hour is able to remove: • 80% of Total Suspended Solids (TSS) for influent concentrations greater than 100 mg/L and achieve a 20 mg/L effluent for influent concentrations less than 100 mg/L. • 60% dissolved zinc for influent concentrations 0.02 to 0.3 mg/L. • 30% dissolved copper for influent concentrations 0.005 to 0.02 mg/L. • 50% or greater total phosphorus for influent concentrations 0.1 to 0.5 mg/L. Ecology's Recommendations: Ecology finds that: • Oldcastle Infrastructure, Inc. has shown Ecology, through laboratory and field testing, that the BioPodTM Biofilter is capable of attaining Ecology's Basic, Total Phosphorus, and Enhanced treatment goals. Findings of Fact: Field Testing 1. Herrera Environmental Consultants, Inc. conducted monitoring of the BioPodTM Biofilter at the Lake Union Ship Canal Test Facility in Seattle Washington between November 2016 and April 2018. Herrera collected flow -weight composite samples during 14 separate storm events and peak flow grab samples during 3 separate storm events. The system was sized at an infiltration rate of 153 inches per hour or a hydraulic loading rate of 1.6 gpm/ft2. 2. The D5o of the influent PSD ranged from 3 to 292 microns, with an average D50 of 28 microns. 3 Influent TSS concentrations ranged from 17 mg/L to 666 mg/L, with a mean concentration of 98 mg/L. For all samples (influent concentrations above and below 100 mg/L) the bootstrap estimate of the lower 95 percent confidence limit (LCL 95) of the mean TSS reduction was 84% and the bootstrap estimate of the upper 95 percent confidence limit (UCL95) of the mean TSS effluent concentration was 8.2 mg/L. 4. Dissolved copper influent concentrations from the 17 events ranged from 9.0 vg/L to 21.1 pg/L. The 21.1 i.tg/L data point was reduced to 20.0 vg/L, the upper limit to the TAPE allowed influent concentration range, prior to calculating the pollutant removal. A bootstrap estimate of the LCL95 of the mean dissolved copper reduction was 35%. 5. Dissolved zinc influent concentrations from the 17 events ranged from 26.1 p.g/L to 43.3 vg/L. A bootstrap estimate of the LCL95 of the mean dissolved zinc reduction was 71%. 6. Total phosphorus influent concentrations from the 17 events ranged from 0.064 mg/L to 1.56 mg/L. All influent data greater than 0.5 mg/L were reduced to 0.5 mg/L, the upper limit to the TAPE allowed influent concentration range, prior to calculating the pollutant removal. A bootstrap estimate of the LCL95 of the mean total phosphorus reduction was 64%. 7. The system experienced rapid sediment loading and needed to be maintained after 1.5 months. Monitoring personnel observed similar sediment loading issues with other systems evaluated at the Test Facility. The runoff from the Test Facility may not be indicative of maintenance requirements for all sites. Laboratory Testing 1. Good Harbour Laboratories (GHL) conducted laboratory testing at their site in Mississauga, Ontario in October 2017 following the New Jersey Department of Environmental Protection Laboratory Protocol for Filtration MTDs. The testing evaluated a 4-foot by 6-foot standard biofiltration chamber and inlet contour rack with bypass weir. The test sediment used during the testing was custom blended by GHL using various commercially available silica sands, which had an average d50 of 69 µTn. Based on the lab test results: a. GHL evaluated removal efficiency over 15 events at a Maximum Treatment Flow Rate (MTFR) of 37.6 gpm, which corresponds to a MTFR to effective filtration treatment area ratio of 1.80 gpm/ft2. The system, operating at 100% of the MTFR with an average influent concentration of 201.3 mg/L, had an average removal efficiency of 99 percent. b. GHL evaluated sediment mass loading capacity over an additional 16 events using an influent SSC concentration of 400 mg/L. The first 11 runs were evaluated at 100% of the MTFR. The BioPod began to bypass, so the remaining 5 runs were evaluated at 90% of the MTFR. The total mass of the sediment captured was 245.0 lbs and the cumulative mass removal efficiency was 96.3%. 2. Herrera Environmental Consultants Inc. conducted laboratory testing in September 2014 at the Seattle University Engineering Laboratory. The testing evaluated the flushing characteristics, hydraulic conductivity, and pollutant removal ability of twelve different media blends. Based on this testing, Oldcastle Infrastructure, Inc. selected one media blend, Mix 8, for inclusion in their TAPE evaluation of the BioPodTM Biofilter. a. Herrera evaluated Mix 8 in an 8-inch diameter by 36-inch tall polyvinyl chloride (PVC) column. The column contained 18-inches of Mix 8 on top of 6-inches of pea gravel. The BioPod will normally include a 3-inch mulch layer on top of the media layer; however, this was not included in the laboratory testing. b. Mix 8 has a hydraulic conductivity of 218 inches per hour; however, evaluation of the pollutant removal ability of the media was based on an infiltration rate of 115 inches per hour. The media was tested at 75%, 100%, and 125% of the infiltration rate. Based on the lab test results: • The system was evaluated using natural stormwater. The dissolved copper and dissolved zinc concentrations in the natural stormwater were lower than the TAPE influent standards; therefore, the stormwater was spiked with 66.4 mL of 100 mg/L Cu solution and 113.6 mL of 1,000 mg/L Zn solution. • The BioPod removed an average of 81% of TSS, with a mean influent concentration of 48.4 mg/L and a mean effluent concentration of 9.8 mg/L. • The BioPod removed an average of 94% of dissolved copper, with a mean influent concentration of 10.6 p.g/L and a mean effluent concentration of 0.6 µg/L. • The BioPod removed an average of 97% of dissolved zinc, with a mean influent concentration of 117 µg/L and a mean effluent concentration of 4 jig/L. • The BioPod removed an average of 97% of total phosphorus, with a mean influent concentration of 2.52 mg/L and a mean effluent concentration of 0.066 mg/L. When total phosphorus influent concentrations were capped at the TAPE upper limit of 0.5 mg/L, calculations showed an average removal of 87%. Other BioPod Related Issues to be Addressed By the Company: 1. Conduct hydraulic testing to obtain information about maintenance requirements on a site with runoff that is more typical of the Pacific Northwest. Technology Description: Contact Information: Applicant: Download at https://oldcastleprecast.com/stormwateribioretention- biofi ltration-appl ication s/bioretention-biofiltration- solutions/ Chris Demarest Oldcastle Infrastructure, Inc. (925) 667-7100 Chris.demarest@oldcastle.com Applicant website: https://oldcastleprecast.com/stormwater/ Ecology web link: https://ecology.wa.gov/Regulations-Permits/Guidance-technical- assistance/Storm water -perm ittee-guidance-resources/Emerging-stormwater-treatment- technologies Ecology: Revision Histo Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas.howie@ecy.wa.gov Date Revision March 2018 GULD granted for Basic Treatment March 2018 Provisional GULD granted for Enhanced and Phosphorus Treatment June 2016 PULD Granted April 2018 GULD for Basic and Provisional GULD for Enhanced and Phosphorus granted, changed name to BioPod from TreePod July 2018 GULD for Enhanced and Phosphorus granted MO Ell MI BELLVVEATHERTC)[}APARTMENTS 4.3 LOW IMPACT DEVELOPMENT BMPS Core Requirement #9 of the 2016 KCSWDMnequires flow contm|0NPs to beimplemented perthe "individual lot BMP Requirements" included in Section 1.2.9.2 for all new and replaced impervious surfaces tothe maximum extent feasible or meet the Low Impact Development Requirement. The Large Lot BMP requirements will be met by evaluating flow control BMPs for the target areas and apply BMPs to the maximum extent feasible. Each 8W1Pwas determined feasible orinfeasible asfollows. 1. FuRCHspersmn—ThesiteisboundedbyS152"^Streettothenorth,andneighbohn8residencestothe west, east and south. With the current site improvements, a native vegetative flowpath of 100 feet cannot bemet, making Full Dispersion infeasible. I Full Infiltration of Roof Runoff —According to the Geotechnical Report created by PanGEO, INC. dated O8/O7/2Ol7'the underlying soils cf the site are dense glacial till soils not suitable for infiltration. Therefore, Full Infiltration ofRoof Runoff is infeasible. ]. Full Infiltration, Limited Infiltration, Bioretention, or Permeable Pavement — According to the Geotechnical Report created by PanGEO, INC. dated 08/07/2017, the underlyingsoils of the site are dense glacial till soils not suitable for infiltration. 4. Basic Dispersion —All on-sitetarget impervious surfaces cannot be treated by Requirements 1-3 and the minimum required vegetated flow path is not available due to the design constraintsofthe site, therefore, basic dispersion is not feasible. 5. Reduced Impervious Surface nrNative GrmmthRetention—Reduced|mpemiousSurfacesaneinfeasib|e due to project constraints and due to the size of the building and parking lot onsite. There are also no feasible native growth areas onsitefor native growth retention. G. Post -Amended Soils —Amended soils will be implemented in all landscaped areas where possible. 7. Perforated Pipe Connection —Infiltration for the site has been determined as infeasible. Till soils are not conducive to infiltration. Therefore, a perforated pipe connection will not be provded. The lot will beconsidered tomeet the requirement tothe maximum extent feasible. JOB #18-183 Technical Information Report 4.18 Achieving the Post -construction Soil Standard Preserving And Restoring Healthy Soils On Site Developments In King County Healthy soil is vital to a clean environment and healthy landscapes. Deep soil that is rich in organic material absorbs rainwater, helps prevent flooding and soil erosion, and filters out water pollutants. Healthy soil also stores water and nutrients for plants to use in dry times, promoting healthy plants that require less irrigation, toxic pesticides, and other resources. Land development and landscaping practices can damage these valuable soil functions by removing or compacting topsoil. The result is erosion, unhealthy landscapes that are difficult and expensive to maintain, polluted water, destroyed fish habitat, and increased need for costly stormwater management structures. Amendments to King County's Clearing and Grading regulations KCC 16.82 help prevent costly environmental and landscape problems by requiring permit holders to preserve topsoil, restore soils by adding compost after construction, or implement other measures to maintain the soil's moisture holding capacity for areas that have been cleared and graded. There are economical ways to retain the benefits of healthy soil, and avoid more costly damage to streams, wildlife, and human health. This booklet explains how to preserve and restore soil quality and to meet these new code requirements. Effective January 1, 2005 King County 1 Department of Development & Environmental Services Ira ' ' - ., r r ' , ^^ ^ I Soil Treatment Options There are four Soil Treatment Options that can be used to meet thepost-construction soil standard. These options can be used individually, or in combination (more than one may be used in different areas of a single site), so that they work best for the situation, The most convenient and economical methods for achieving the standards depend on site soil conditions, grading and subgrade compaction, practicality of stockpiling site topsoil during grading, and site access issues. Choose Option 2, 3,4a and/or 4b to restore soil quality after construction in areas where grading and soil disturbance are unavoidable, and follow these requirements: 'When amending soil, dompbetween May 1and October 1only. ^ Final soil depth should beaminimum cf8inches. ^ Avoid plowing o,tilling within drip line uftrees mberetained, ^ Test soil PH, and ifnecessary, adjust u»suit proposed plants. Option 1* Leave native soil undisturbed, and protect from compaction during construction. NOTE: Option 7bonly applicable msites that have the undisturbed 5u0native mthe site. This will most often beforested land that isbeing left undisturbed inthe cunnntpnoject. This option isthe most economical and best for the environment, but isnot always feasible. ~ Plan site development toleave areas where native vegetation does not need tobedisturbed. ^ Fence off areas ofnative vegetation nnthe site that will not be stripped, logged, orgraded toprotect them from disturbance during construction. ' Undisturbed areas donot require soil amendment. Regulatory Requirements "°�:� =°��'� ""�°� " ^^~~ Except for areas that will be covered by impervious surface or have been incorporated into a stormwater facility, areas that have been cleared and graded must have the soil moisture holding capacity restored to that of the original undisturbed soil native to the site to the maximum extent practicable. Areas that have been compacted n,had the topsoil ordufflayer removed will beamended by adding compost, importing topsoil, stockpiling site topsoil, or through other techniques that are capable cdmitigating for lost moisture holding capacity. Soil amendment shall take place between May l andOctober l Replaced topsoil shall be a minimum of eight inches thick, unless the applicant demonstrates that a different thickness will provide conditions equivalent to the soil moisture holding capacity native to the site. Replaced topsoil shall have an organic matter content of between 8 to 13 percent dry weight and a PH suitable for the proposed landscape plants, (Note: 8-13% soil organic matter (SOM) content in soil is notthe same as 8-13% by volume of compost in soil, but rather approximately 30-40% compost by volume in soil. This booklet explains how to achieve the required 8-13% soil organic matter content.) |tisalso recommended that compacted subsoils betilled orplowed before placing amendments nrtopsoil, and that planting beds be mulched with two inches offorest duff,ground bark, wood chips or other organic material after planting. These standards apply mall site development activities, whether permits are required ornot, except for surface mine operations conducted pursuant tupermits issued byKing County and the Washington Department ofNatural Resources. 2 King County Department of ��m��°��0�"�* _~�-~�~~�~ Amend existing soil in place. Where the soil has been compacted orthe forest duffortopsoil removed, the simplest way torestore soil quality istumt till compost into the existing soil. `Apply alayer ufcompost toexisting soil atthe pre -approved amendment rate my2,5inches. Use the Compost and Topsoil {a|cua|honWorksheetinthis booklet orthe online Compost and Topsoil Calculator (see Resources page 6)oocalculate the quantity ofcompost needed. NOTE. If desired, ocustom compost amendment rote may be used usonalternative mthe pre -approved amendment rote (see Pre -approved versus Custom Amendment Rates page 3). `Retain copies ofcompost test results and receipts for compost delivered unthe site, as they will beused during inspection tn verify the soil requirements have been met. ^ RototU|compost into soil toadepth vfatleast 8inches. Note that tilling mthis depth will require mp*vtedpooawith olarge machine, such osutractor mounted nrheuvyremrtine mmtiller. Option 3: Import topsoil mix with 8-1396soil organic matter content. Where subsoil istoo rocky, compacted o,poorly drained toamend effectively, atopsoil mix withO 139h soil organic matterb imported and placed on the surface. "Manufactured" topsoil mixes should be weed free, making them ideal for seeding new lawns, `Import and apply atopsoil mix with 8-l3%soil organic matter, which should contain 3V-4V9hcompost byvolume, and clean sand orsandy soil. The soil depth should beOinches and the pM suitable for proposed plants. ^Use the Compost and Topsoil Calculation Worksheetinthis booklet nrthe online Compost and Topsoil Calculator (see Resources pageWmcalculate the quantity uftopsoil needed. ^Ask topsoil suppliers for test results mftheir product toverify the material contains the desired organic matter content and pH. Retain copies of topsoil test results and receipts for topsoil delivered mthe site, as they will beused during inspection to verify that the soil requirements have been met. ` For best results, plow nrtill compacted subsoil atleast 3inches deep before applying topsoil mix, and/or mtod||some ofthe newly applied topsoil into the subsoil. Achieving the Post -construction Soil Standard Option ��� ��mm�° ��m~Nw �nmm ~~ m�mwmmnvn�-mm�mNw Stockpile site cluff and topsoil, and reapply after grading and construction. NOTE: Option 4a is only applicable to sites that have the original, undisturbed soil native tothe site. This will most often beforested land that is being converted inthe current project. Topsoil and forest duffexcavated for structures and paved areas, nrremoved before site grading, can bestockpiled and reapplied after grading urother construction disturbances are completed. Stockpiling may not bepractical onsmall sites. ^Remove forest duff layer and topsoil stockpile an approved location prior to grading, Cover soil and cluff piles with woven weed barrier (available from nursery supply stores) that sheds moisture yet allows air flow. ' Reapply topsoil tnlandscape areas toominimum 8inch depth after grading and other disturbances are completed. ^ For best results, plow ortill compacted subsoil atleast 2inches deep before replacing stockpiled topsoil, and/or mktiUsome cf the replaced topsoil into the subsoil. ^Apply aZ'inchlayer nfstockpiled duffasamulch after planting. versus Custom Amendment Rates Apre-approved soil amendment rate has been calculated for Soil Treatment Options 2and 4bpresented inthis booklet. The pre -approved rate bl5inches ofcompost, applied mthe soil as directed. Use ofthe pre -approved amendment rate may simplify planning, however acustom calculated rate, based ontests ufthe site soil and proposed compost, can save oneffort and expense. Many pasture orwoodland soils have adequate organic matter without amendment. Also, some compost products will provide the required soil organic matter content atlower application rates than the pre -approved rate. See Soil Testing Laboratories under Resources inthis booklet for how tufind accredited laboratories for soil testing. Tucalculate acustom compost amendment rate, identify the values below and use the o,(ineCompost and Topsoil Ca|cu|atn,(see Resources page6). Values tncalculate acustom compost amendment rate mbe mixed into anOinch depth ofsoil: `Target soil organic matter (%)- the desired percentage organic matter (8-l]9@upon completion ^Soil bulk density (|bs/cubicyard dry weight) - obtained from soil testing ^Soil organic matter (0/W-obtained from soil testing ^Compost bulk density (lbytub|cyard dry weight) -obtained from compost testing ^Compost organic matter obtained from compost testing Retain soil and compost test results, as they will beused during inspection tnverify the soil standard isbeing met. Achieving the Post -construction Soil Standard 4Co"0 Treatment Options Option ���� Disturbed ~mm�~~ ���.����wm�wmmm ��mp�mw Stockpile site soil, reapply, and amend in place. NOTE: Option 4bbonly applicable tosites where the soil is not the original, undisturbed soil native tnthe site. This will most often beun6nestedareas, ` Remove soil and stockpile inanapproved location prior ^u grading. Cover soil with woven weed barrier (available from nursery supply stores) that sheds moisture yet allows air flow. ` Reapply stockpiled soil tnlandscape areas toaminimum hinch depth after grading and other disturbances are completed. (n some cases, purchasing additional topsoil will beneeded tu achieve the 6inch depth. ^ For best results, | till compacted submi|e/|aotZinches deep before replacing stockpiled soil, and/or mtotiUsome ofthe replaced soil into the subsoil. ^Apply alayer of compost to the reapplied soil atthe pre - approved mmendmentnntemf2.5|ncheu.Usethe[ompust and Topsoil Calculation Worksheetinthis booklet orthe online Compost and Topsoil Calculator (see Resources page 6)to calculate the amount ofcompost needed. NOTE. Ifdesired, ucustom compost amendment rote may boused munalternative to theore'appmvodomondmentmte (see Pre - approved versus[usmmAmondment8wtes thbpugo). ^Retain copies ofcompost test results and receipts for compost delivered nothe site, asthey will beused during inspection tn verify the soil requirements have been met. ' Rototi||compost into soil toadepth ofatleast 8inches. Note that tilling mthis depth will require myeotedpmoeswith ularge machine, such osotractor orheavy rear tine mmti0or. King County 3 --Department mDevelopment ^' . .. r ` .. `~ Figuring Compost Stockpiling and/or Imported Topsoil Needs ������ ���0�� �m�� mw �m���° Review site conditions, landscape and grading plans. 0 Examine site plans and soils. Use ashovel »odig inseveral areas that have been orwill begraded Vndetermine if the newly exposed grades can bpeasily amended, orif compaction will require plowing/tilling ofthe subsoil or topsoil import. Determine ifthere are areas where soil could bestockpiled on -she. O Identify areas where soil can be: left undisturbed (Option l\amended inplace with compost (Option 2).removed and replaced with imported purchased topsoil (Option 3\or stockpiled and later reapplied (Options 4aand/or 4b). ��m�K�|�� �&n�k�U,��*U��U� �0�^�U�^��004���� Permit "^ «�0�orn"w�vm Requirements ""�� Tmensure that the post -construction soil standard will be met, permit application submittal must include: ^ Completed Soil Management Plan form, with required attachments, including asite plan marked tooutline areas where each soil treatment option will beapplied, and any stockpiling orstaging areas. ` Either acompleted Compost and Topsoil Calculations Wo,hsheet(see pages 0-7).oraprint-out mfthe calculation results from the online Compost-a.-ndTopsoi|.Cm|culatwr Note: The online {oTpmstvnd7opsoV{olcuhatorcan he used for either pre -approved o/custom amendment rates, The Compost and Topsoil Calculation Nhrkohect inthis booklet should only heused ifthe pre -approved amendment rate will heused for Options 2and 4h. ` Test result reports for compost and/or topsoil products that will beused for the project. These will beused during inspection tnverify that the soil requirement has been met. ��.^U �� .�~,Un 83" o Use anaccredited soil testing laboratory tntest the pHofthe soil and ask the laboratory mprovide information onhow m adjust the soil pH, should that bpnecessary. Tnfind accredited soil testing laboratories, see Resources onpage I Anursery can provide specific information about suitable pH for landscape plants. Here are optimal soil pHranges for various plant types: Lawns -5.5»mI5pH Shrubs (except acid -tolerant plants) -l5m7.0pH Acid -Tolerant Shrubs (Rhododendrons, Azaleas, Mountain Laurels, Camellias, Blueberries, native plants) -4.5 toI5pH Annual Flower and Vegetable Gardens -0.OmTOpH 4 King County Department of Development & Environmental Services Select soil treatment option and suitable pH for each planting area. Amending with compost isoften the most economical way tn bring poor soils up to the i d soil organic matter content. On sites with the original, undisturbed, native soil, and where space permits, stockpiling and reapplying topsoil may beless costly. Importing topsoil usually costs more than amending existing soil, though hmay beeasier where subsoil conditions make cultivation Ll Ifinterested inusing acustom compost amendment rate for Options 2and/or 1b,use anaccredited soil testing laboratory msample and test the site soil todetermine the soil bulk density (|bdcubicyard dry weight) and soil organic matter percentage, These values will beused mcalculate the custom compost amendment rate ininches (see Pre -Approved versus Custom Amendment Rates page ]). 13 Identify the areas where the selected 5ollTeotment Option(s) (see pages 2-3)will beapplied. Outline those areas onthe she plan with adark, thick -line pen. LJ Assign each area anidentifying letter K\B,... nnthe site 0 Determine desired pHfor each lettered area, based on suitability for proposed plants (see SoilpH this page). [\ Include required information with permit application (see Permit Application Requirements this poge). ������ `~w�m �° Calculate compost and/or topsoil volumes for each area. 0 Calculate the square footage ofeach lettered area onsite plan. Ll Ifusing the pre -approved amendment rate, complete the Compost and Topsoil Calculation Nhdohasn,use the online Compost and Topsoil Calculator (see Resources page Wm calculate the quantities pfcompost and/or topsoil needed, 0 Ifusing acustom amendment rate, only the online Compost� and Topsoil Calculator can heused mcalculate compost Achieving the Pos'constructionSoil Standard r Figuring Compost, Stockpiling and/or Imported Topsoil Needs STEP 4. Identify compost and/or topsoils to be applied and retain records. ❑ Contact compost or topsoil sources and select products that meet the requirements, including 8 - 13% soil organic matter content for topsoil mixes and suitable pH for the proposed plants. • Topsoil should contain 30-40% of compost by volume. • Compost should contain 40-60% organic matter. ❑ If preparing to use a custom compost amendment rate for Options 2 and/or 4b: • Determine the target percentage of soil organic matter (8-13%) you wish to achieve Note: 8% is better for grassy areas and lawns and 10-13% is better for planting beds. • Request copies of compost test results reports that include the compost bulk density (Ibs/cubic yard dry weight) and the percentage compost organic matter. These values will be used to calculate the custom amendment rate in inches (see Compost and Topsoil Sources and Requirements on page 6 for more information on compost test results requirements). • Use the online Compost and Topsoil Calculator to calculate the custom compost amendment rate in inches and the quantities of compost and/or topsoil needed for the project. Print the calculation results. ❑ Complete the Soil Management Plan form in this booklet, with required attachments. These will become part of your permit documents (see Permit Application Requirements page 4). ❑ Retain compost and/or topsoil product delivery tickets and test results, as they will be used as verification records during inspection. What is the human impact on soils? 55-70% surface water runoff (carries pesticides, silt and animal waste) 15% surface water detained/ infiltrated -cop \ \ 1 5-30% evapo- o ,transpiration r 0 nfall detained Subsoil Groundwater Bedrock Achieving the Post -construction Soil Standard Q King County Department of Development & Environmental Services 5 r • ; Compost and Topsoil Sources and Requirements Compost sold in Washington must comply with state standards for compost quality found in the state solid waste rule (WAC 173-350-220). Compost sources include both permitted compost facilities and facilities that don't require permits because they are exempt under the state rule. Some compost facilities produce compost and topsoil mixes, and topsoil supply companies may use compost produced elsewhere to create topsoil mix products. To achieve the post -construction soil standard, topsoil mixes must contain 8 - 13% soil organic matter content. Ask topsoil suppliers for test results of their product to verify it contains the desired organic matter content and pH; and ask compost suppliers for test results to verify that the compost contains 40-60% organic matter. If using a custom amendment rate, you will also need to know the compost bulk density (Ibs/cubic yard dry weight). Permit applicants that compost their own material at a maximum of 250 cubic yards of compost on site at any one time, may use that material for a project, provided the appropriate tests are conducted and documented. In addition to the annual testing required by WAC 173-350-220, tests must include: 1) organic matter content (range: 40-60%); and, if using a custom compost amendment rate, compost bulk density (Ibs./cubic yard dry weight). Retain test result reports for compost, as well as receipts for compost and/or topsoil delivered to the site by suppliers. These will be used during inspection to verify the soil standard requirements have been met. See Resources for how to find a list of permitted compost facilities. You may also see your local business directory for producers and suppliers of compost and topsoil products. Resources Permitted Compost Facilities For a list of permitted compost facilities, see the Washington State Department of Ecology Web site at http://www.ecy.wa.gov/programs/swfa/compost/, and click on "Permitted Compost Facilities" in the text, or call the Department's Northwest Regional Office at 425-649-7000. Compost and Topsoil Calculator To calculate the amounts of compost and/or topsoil needed for a project, as well as a custom compost amendment rate, use the online Compost and Topsoil Calculator, which can be found on the DDES Web site at www.metro kc.gov/c1 n rp/swd/compost_ca lcu la to r. ht m. Soil Testing Laboratories For a list of accredited soil testing laboratories and guidance on obtaining soil tests, contact the Washington State University King County Extension at 206-205- 3100 or 1-800-325-6165 ext. 5-3100. Learn More SoilsforSalmon.org - why and how to build healthy soil, case studies, and other resources. Contacts For questions related to King County's post - construction soil standards, please contact: Richelle Rose, DDES Land Use Services Division Ph - 206-296-6608 Fax - 206-296-7055 E-mail - richelle.rose@kingcounty.gov TTY Relay: 711 Puget Sound Online - Low Impact Development - information on environmentally sensitive land development techniques (http://www.psat.wa.gov/Programs/LID.htm). 6 King County Department of Development Environmental Services Achieving the Post -construction Soil Standard Compost and Topsoil Calculation Worksheet for the Pre -approved Amendment Rate NOTE: For Options 2 and 4b, use this worksheet if you plan to use the pre -approved compost amendment rate of 2.5 inches. This worksheet should not be used if a custom compost amendment rate is selected for Options 2 and/or 4b. Instead, use the online Compost and Topsoil Calculator at www.metrokc.gov/dnrp/swd/compost_calculator.htm. Option 1 Leave native soil undisturbed, and protect from compaction during construction. Enter lettered areas from site plan where this option will be used: No calculations for compost or topsoil are necessary for this option. Option 2 Amend existing soil in -place (2.5 inch layer of compost). Enter lettered areas from site plan where this option will be used: A Enter combined square footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter .5) Multiply combined square footage by 8 and enter product in box A Option 3 11.34 x8 A = 90.72 Cubic Yards AMOUNT OF COMPOST NEEDED FOR THESE AREAS Import topsoil mix with 8 - 13% soil organic matter (8 inch depth of topsoil). Enter lettered areas from site plan where this option will be used: Enter combined square footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter .5) Multiply combined square footage by 25 and enter in box B x 25 AMOUNT OF IMPORTED TOPSOIL NEEDED FOR THESE AREAS Option 4a Native Soil - stockpile site duff and topsoil and reapply after grading and construction. Enter lettered areas from site plan where this option will be used: Enter combined square footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter .5) Multiply combined square footage by 25 and enter in box C Achieving the Post -construction Soil Standard x 25 Cubic Yards AMOUNT OF SITE TOPSOIL TO BE STOCKPILED AND REAPPLIED IN THESE AREAS *King County Department of Development & Environmental Services 7 r r Compost and Topsoil Calculation Worksheet for the Pre -approved Amendment Rate Option 4b Disturbed Soil - Stockpile site soil, reapply, and amend in place (2.5 inch pre -approved amendment rate). CALCULATE STOCKPILED SOIL NEEDED Enter lettered areas from site plan where this option will be used: Enter combined square footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter .5) Multiply combined square footage by 19 and enter in box D x 19 D Cubic Yards AMOUNT OF SITE TOPSOIL TO BE STOCKPILED AND REAPPLIED IN THESE AREAS CALCULATE COMPOST NEEDED Enter lettered areas from site plan where this option will be used: Enter combined square footage of lettered areas in thousands (example: for 4,525 sq ft, enter 4.525; for 500 sq ft, enter .5) Multiply combined square footage by 8 and enter product in box E x 8 AMOUNT OF COMPOST NEEDED FOR THESE AREAS Note: If there is less stockpiled site topsoil than the amount needed to achieve the 8 inch depth once reapplied (amount in box D), additional topsoil should be purchased to make up the difference. Subtract the cubic yards of site topsoil available to be stockpiled from the total amount needed in box D to find the difference —the amount of additional topsoil that will need to be purchased, r Add this additional topsoil amount to the amount in box 8 and enter in box G. r $ * Order These Amounts Add amounts in boxes A and E and enter here Enter box B amount here (if using Option 4b, see note under Calculate Compost Needed) 8 King County parenent of Development Environmental Services Achieving the Post -construction Soil Standard Soil Management Plan For Post -construction Soil Standard (KCC 16.82) 12/5/06 King County Department of Development & Environmental Services 61. Use Achieving the Post -construction Soil Standard booklet instructions to carry out this Soil Management Plan. 4=0 Project Information Complete all information on page 1, only site address and permit number on additional pages. Site Address / Lot No.:3481 S 152nd St, Tukwila, WA 9818 Permit Type: Construction Permit Number: TBD Permit Holder: Bellweather Tukwila, LLLP Phone: (206) 588-4821 Mailing Address: 1651 Bellevue Ave Seattle, WA 98122 Contact Person: Emma Geyer Phone: (206) 588-4821 Plan Prepared By: Blueline Attachments Attach the following to this plan: • Scale site plan drawings that include areas to be treated with Soil Treatment Options 1, 2, 3, 4a and/or 4b • Completed Compost and Topsoil Calculation Worksheet or printout of online Compost and Topsoil Calculator results. These calculations will be verified in the DDES permit office. • Original compost and/or topsoil test results reports demonstrating that products contain adequate organic matter (for soil treatment options 2, 3 and/or 4b) o Topsoil should contain 30-40% of compost by volume, which is equivalent to 8-13% soil organic matter). o Compost should contain 40 - 60% organic matter. Note: Retain original delivery tickets for compost and/or topsoil products for verification purposes. Soil Treatment Options for Areas Identified on Site Plan Soil treatment options available: • Option 1 - Leave native soil undisturbed, and protect from compaction during construction. • Option 2 - Amend existing soil in place. • Option 3 - Import topsoil mix with 8-13% soil organic matter content. • Option 4a - For native soil: stockpile site duff and topsoil, and reapply after grading and construction. • Option 4b - For disturbed soil: stockpile site soil, reapply, and amend in place. FOR DDES USE ONLY Plan Approval Record Date: Reviewer: Areau A(refer to lettered areas mapped on site plan) sgare footage: 11,340 Selected soil treatment option: ['Option 1 pOption 2 uOption 3 pOption 4a ['Option 4b If using option 2 or 4b, select type of amendment rate: aPre-approved (2.5") pCustom (with %Target Soil Organic Matter) Area (refer to lettered areas mapped on site plan) Square footage: Selected soil treatment option: Option 1 pOption 2 ['Option 3 uOption 4a ['Option 4b If using option 2 or 4b, select type of amendment rate: DPre-approved (2.51 LiCustom (with %Target Soil Organic Matter) Area (refer to lettered areas mapped on site plan) Square footage: Selected soil treatment option: Option 1 pOption 2 ['Option 3 ['Option 4a pOption 4b If using option 2 or 4b, select type of amendment rate: [IPre-approved (2.5") ZICustom (with %Target Soil Organic Matter) Use additional Soil Management Plan forms for additional areas, if necessary. Record the compost and/or topsoil products to be used Compost Product #1: Cedar Grove 60/40 lawn mix Test Results: 6 0 % organic matter content Quantity: 9 0 . 72 cubic yards Supplier: Cedar Grove Composting Product #2: Garden Mix Test Results: 5 0 % organic matter content Quantity: 9 0 . 72 cubic yards Supplier: Washington Rock Quarries, Inc. Total cubic yards of compost 9 0 . 72 Topsoil Product #3: Test Results: % organic matter content Quantity: cubic yards Supplier: Product #4: Test Results: Quantity: Supplier: Total cubic yards of topsoil % organic matter content cubic yards Page of Approved: Date: Reviewer: Approved: Revisions Required: Revisions Required: Achieving the Post -construction Soil Standard Contacts For questions related to King County's post - construction soil standards, please contact: Richelle Rose, DDES Land Use Services Division Ph - 206-296-6608 Fax - 206-296-7055 E-mail - richellesose@kingcounty.gov TTY Relay: 711 0 King County Department of Development 84 Environmental Services This material will be provided in alternative formats upon request for individuals with disabilities. PA/u1,11/ OF NE 333 •075055 X 3 OW TYPE, 00025 If ONCE 325.90 OF) 12%; if (E) ' to; 32e,,,,(c) j I n0E23,0/11 1 1 '1' Cat If I szaTEJ I 1 '7'1" 1 1 RI 11 /1PE2222588 /2022511I 114,41 (f) 0555285580151 JIJE In If J1585 (CI Ir FitC 325.85 (5) DIE 115 75 (iU) C201 /IF &Lax ow „-;2" AC SO NE 1/4, SW 1/4, SEC 22, TWP 23 N, PEE 4 E, W,M, -----..— ., 1 ' , I 1 1 I 1 1 ) , 1 1 1 1 III! ,., s'ar RIVATE ACC PROPOSED APARTMENT BUILDING LEM 1 FFE 33450 SA RASE rrE 324.50 ;Alarm gass ------ nau 10 V7-01 Yr SCALE: 1" = 20' FOOTING DRAIN NOTES I. MON DRAWS TO e AVOID PI OP 424 WAS4Ell ROIX ARAM W/1101101 ea OROS MIR 57501926759260 0.00 2 LtEMOUTS 4fERALKSIIR RIVE RIES SRAil IlAIT CAST RCA RfNC OM SET Rla WIN iltal GRADE COOTS $0f7 AREAS TC VOW COME MARS I. BROS PIS. PIC (AS NEESSARV 10 FE OURRIG BY CONTRACTOR S. MORK ANS TO BE LAD RAT co ork PUPIL SICK TOWARDS MEM 11/PR51609D STOW $15131 6. cars SRC BE PRONE BUY 1004 1.15'N DRECIICK UNDERGROUND UTILITY NOTE 01251014505(5264506407512C471075454625 NO COMTE NT All OM NS ARE AORN, OP NAT TIE LOCO"( AND OM 6 55151245047514510951704552415 MOO AL 640089514445442745100097406910511410926 CCAWECM OCCUR FAY TO TRENCOG OR EMAVADOR MY FR CR STRUMS, ro EWE AVM MAW SEE Ale NAM 7851004526551726 SR& 44807851 WPREPRIA TE MINOR KR FROTEM OF SAID FAXIES, IRE CGCRACTX 941 NOVI NIL AT (111.90610.611.660 AND AARANDE FOP FED LCCAZR caw FAMES EDW. ovum* BLUELINE iSOUVOY SaTEM NNW VA NY NE MIMI ..2161(92 1.1.1*,,tikEAGIIMON 545226 PAW MOAB: icftcy itieZ PE PROV EKING: Atrefaq DEM somm SE DATE: /2,0,9 .SER. 1E1-183 ET NA, CAE 5442 I Or IC BELLVVEATHERT{]DAPARTMENTS Section «� y- Design ���~����.� ^~���������6�w��<gn PUMP DESIGN BETWEEN THE PUMP SYSTEM AND CB 2 The duplex pump system will consist of2FlygtModel DPN1OO'2GSO pumps which will beinstalled |nanO|dcaste Onel-ift packaged wetwell located in the southern portion of the parking lot, just east of the detention vault. The pump system will operate based on float switches and on an automatic timer for long flow durations. One pump is designed to operate with the second pump designed as an alternate pump that will switch on when the other turns off to reduce the continuous run time of the pumps. The pump system will convey the flows approximately 300heet via a G" force main to CB Z installed just south of the northern parcel boundary near 5 1S2""Street. Seethe pump specification onthe following pages. Total Head Calculation Total Head =Static Head + Dynamic Head Static Head 20 feet The Hazen -Williams equation was used toestimate friction loss within the force main: 100 \1us z000 / = U3O83 "�^,S\/- ^ ` where: f = friction loss per 1O0feet ofpipe [~f|ow coefficient 4 150for HDPE D=flow rate =O.9S99cb=4498pm' D/ = inside diameter mfpipe, in -) 6inches 150 (zoo\ 'os (^*v `' vo \ / = 0.2O83 \��/ \ 64.o6,s / -1.314ft per 1O0feet ofpipe Dynamic Head =(3OOfeet)*1.314ft/10Oft=3.g4fewX Total Head =20ft(static)+4.O9ft(dynamic)=33.94ft Flow Rate =lOOYear unmitigated (VVVVHW1281%)=O.9S99ds=449GPM PUMP REQUIREMENTS: PUMP RATE: 449GpM TOTAL HEAD: 23.94 feet The pump has been designed to convey the 100-year unmitigated flow from the vault and pump it up to the north side of the site into CB 2. Therefore, in the attached Backwater Spreadsheet, the pipe runsattached tothe pump station have been excluded because nobackwater effects will occur during the 1OD'yearstorm. JOB #18-uo Technical Information nzpor-t 51 Concertor DP N100-2650 A process -controlled wastewater pumping system suitable for customers who utilize specially designed process control algorithms and want to benefit from lower capital costs, smaller control cabinets and higher pump system efficiencies. Concertor DP is also suitable as a reliable and energy efficient on/off controlled wastewater pum ping system for customers who want to benefit from easily adjustable pump performance, soft start/soft stop, constant power and motor protection. This system is scalable to as many pumps as required by yourapplication, with one gateway per pump. Technical specification Configuration a xylem braid Curves according to: Water, pure [100%],39.2'F,62.42 Ib/ft3,1.69E-5 ft2/s [81 He 104= 100= 96= 92_ 68= 84= 80-: 76= 68= 52-_ 48= a2= 28 24-E 20= 16= 12= 4= 0= 1 f"r 400 600 800 1000 1200 [US g.p.m.] Curve: 150 9906 Motor number N6020.091 18-08-1AZ-W 10hp Impeller diameter 200 mm Pump information Installation type P- Semipermanent, Wet Discharge diameter 3 15/16 inch Set power 2650 W Materials Impeller diameter 200 mm Discharge diameter 315/16 inch Inlet diameter 120 mm Maximum operating speed 500-2175.3 rpm Number of vanes 2 Impeller Hard -Iron^' Pmlect Created by Block Created on 9/24/2019 Last update L. . Concertor DP N100-2650 Technical specification Motor - General FLYGT a xylem brand Motor number Phases Rated speed Rated poster N6020.091 18-08-1AZ-W 10hp 3` 500-2175 rpm 10 hp Approval Insulation class Rated current Type of Duty FM H 10.9A 51 Frequency Rated voltage 60 Hz 460 V Motor - Technical Starting current 10.9 A Project Created by Block Created on 9/24/2019 Last update Concertor DP N100-2650 Performance curve Duty point Flow Head 451 US g.p.m. 21 ft a xylem brand Curves according to: Water, ,39.2 7,62,42 lb/fe,1.69E-5 s E; Heed 507 401' 46- 44- 42- 40- 38- 36- 34- 32- 30- 28- 26- 24- 22, 20- 18- 16- 14- 12- 10- 8- 6- 4- 2- ump Efficiency so= Persil Efficiency 501 40 30 20 101 0 , Pewor th1,1741,0 DI 3.0- 2.5- 2 759. 3.135 hp 1. 13.28 hp_ 24-, 16 12 NPSH-values 451.3 650 0 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 950 1 Curve: ISO 9906 Project Created by Block Created on 9/24/2019 Last update Concertor DP N100-2650 Duty Analysis [fil:Flead 50: 48- 46 44- 42- 40: 38- 36- 34- 32- 0 28: 26: 24: 22- 207- 18- 16 14- 12- 10- 8 6- 42- - FLIEGT a xylem brand Curves according to: Water, pure 100%J 39.2 "F,62.42 lb/fe,1.69E-5 ft9i 2650 21 ft 4513USgp.nt 11111111 1111 100 200 300 400 500 600 700 800 900 [US g.p.m.] Operating characteristics Curve: ISO 9906 Pumps/Systems Flow Head Shaft power Flow Head shaft power Hydr.eff. Specific energy NPSH r 1 451 US g.p.m. 21ft 3.28 hp 451 U5 g.p.m. 21 ft 3.28 hp 73.1 % 101 kWh/US Mi 8.19 ft Project Created by Block Created on 9/24/2019 Last update Concertor DP N100-2650 Dimensional drawing F a xylem brand z to or, Z-Z 43020 • mr Mgt pjSat Its 2E8 95 1°,....0.0 1:10 180(i28 '••••• -1 93341 CO I2 Probed Created by Block Created on 9/24/2019 Last update NO OBI 30'x48' HATCH CH SAFETY RAIL 3001 PEDESTRIAN RATED, H2O AVAILABLE) INCOMING ELECT/CONTROLS LOCATION EITHER SIDE INLET LOCATION & ORIENTATION AS REQUIRED SUBMERSIBLE PUMPS YAWSEC1lQN OR GRINDERS COMMONLY SELECTED OPTIONS LIST: _ H2O LOAD RATING ON HATCHES 1 PASSIW VENT LOCATION EITHER SIDE 30'x36" HATCH (3001 PEDESTRIAN RATED, H2O AVAILABLE) DISCHARGE POSITION N1 (SHOWN) DISCHARGE POSITION 02 SAFETY GRATING FOR VALVE VAULT HATCH LADDER EXTENSION FOR VALVE VAULT ACCESS ADMIXTURE FOR HYDROGEN SULFIDE PROTECTION NON-FIBRATED EXTERIOR DAMPPROOFING BYPASS IV/ISOLATION VALVE AND QUICK CONNECT (2" 4") DISCHARGE PRESSURE GAUGES _ VENTING WITH ODOR CONTROL _ TRANSDUCER IV/FLOAT LEVEL CONTROL INTERIOR JUNCTION BOX EXTERIOR JUNCTION BOX _ ALUMINUM OR STAINLESS STEEL TRASH BASKETS STAINLESS STEEL PORTABLE HOIST (300#, 1000#) 2' OR 4' VALVE VAULT EXTENSION RISERS TO INCREASE HEADROOM OR FORCE NLMN COVER WHEN REQUIRED, COMPLETE LIST OF OPTIONS AVAILABLE IN THE ONELIFT SPECIFICATION GUIDE. APPRvn. WEIGHTS: BASE SECTION WVTLOAT COLLAR & FILLETS =11.0 TONS TOP SLAB & VALVE VAULT ARE FACTORY SEALED, AND SHIP AS PIECE =9.5 TONS 2' RISER SECTION =2.0 TONS 4`RISER SECTION=4.OTONS 3'-0" 15'-10" EL 312,85-BU FLOAT HHWA ALARM .50-JAO p ON a 312,25-LEAD PUMP ON EL 310.75-PUMP OFF EL 310.25-BU PUMP OFF + ALARM 4' SCH80 PVC VENT _ ,.J VOLUME - 39.64 CF/FT 297 GAL OPT: TRANSDUCER A SST RAILS GUIDE Dam ELEVATION NIT BC509 z —6' WAILS 1-0" OPTIONAL 4'BTPASS IE 318,79-6' OUTLET 3'-0" 2'-0` POTION lT PUMP INFO DESIGN FLOW (GPM) DESIGN HEAD (TDH) HORSEPOWER (HP) VOLTAGE/PHASE RPM MANUFACTURER MODEL # IMPLELLER DIA. PUMP DISCHARGE, is STATION PIPING SIZE, in, SYSTEM INFO AVERAGE DAILY FLOW (ADF) OPERATING HOURS PEAKING FACTOR FORCE MAIN VELOCITY (TVs) FORCE MAIN SIZE, in, FORCE MAIN HIGH ELEV. LENGTH OF FORCE MAIN, fl. TIE IN PRESSURE, psi REOD STORAGE (min.) One111 STATION SCHEDULE 100 yr FLOOD ELEV. TOP OF STATION ELEV. INLET 1 ELEV,ISIZE INLET 2 ELEVUSIZE (In,) INLET 3 ELEV./SIZE (in.) HHWA (FLOAT) HIGH WATER ALARM LAG PUMP ON LEAD PUMP ON PUMPS) OFF BACKUP OFF LEVEL (FLOAT) STRUCTURE INVERT ELEV. BOTTOM OF STA. ELEV. DISHARGE PIPING SIZE E)2" 1E3" 04" DICHARGE PIPING MATERIAL EPVC LEDIP UO1he1 DISCHARGE POSITION E]p1 D62 013 DISCHARGE PIPE ELEV. ONEUFT IS PROTECTED UNDER AT LEAST ONE OF U.S. PATENT NUMBERS U9,587,392; D736,834; D736,835; D737,333 AND HAS OTHER PATENTS PENDING. BEE. 6'0.28,27 CF/FT 8' -50,26 CF/FT RC509a39.64 CF/FT 297 Gal/Vert FT Oldcastle Precast' WATER I � Tit C0/1 "161N PPTpB N Mt AIEW K rt 6 (iluEtR6Y. NM FlR NE694RINZ R11, R09WL NH( E90 N OW RYRR06W 1101051 p FWD( F6q 0ffe'Np R0.6n[ Ka r 07930 0 All UM K, xl 0)115 6�6I ONELIF PUMP STATION 9D1NEV€V HOUK K. INMIA KM DM, OM NW IMES N0 SOS NiAlA [RBPEER 9452019 SLB GEO SkiS aiDEF >RB,66� m1942.5M ARCSC9a,1 G` 1 REP61R &2119 BELLWEATHERTODAPARTMENTS. r CONVEYANCE SYSTEM DESIGN TRIBUTARY TO DETENTION VAULT ow The conveyance system was designed per the requirements within the 2016 King County Surface Water Design x� � For simplicity, the conveyance system was sized so that headwater elevations remained below rim elevations for the 100'year, 24'hourstmrm event. The IS -year, 24'hour storm evert would, then, also remain below rim elevations. Aconveyance sheet was generated using the rational method to calculate flows for each area collected by each basin. See attached C8 Tributary Area Exhibit on the following pages. The rainfall intensity was calculated based unisop|uvia|maps provided within the ZO16KCSVVDK8. 4 weighted C value was used for each area collected by each catch basin. The average C value is based on the total area collected by the catch basins. The catch basins collect a total area of 1.39 acres. The pervious and impervious areas collected by the catch basins are 0.27 acres and 1.12 acres, respectively. The frontage bypass area of 0.03 acres will not be included in the C value calculation, but the in -lieu areas of 0.03 acres wilil be included. As such, the average [ Value is[(O.J7*O.2S)+(1.1]*O.9O)]/1.39=O.77. The taikmaterelevation within the detention vault isthe maximum water surface elevation ofthe vault which is set at the overflow of the control structure. The maximum water surface elevation is 320.21 feet. Asshown onthe spreadsheets onthe following pages, all headwater elevations remained below the rims during the 100-year storm. Therefore, both storms meet the requirements of the 2016 KCSWDM. JOB #18-183 Technical Information Report sz BELLVVEATHEFlTO[)APARTMENTS ON -SITE PIPE CAPACITY Using K8anninu'sequa1ion' the onsbe 12" [PEP pipes (dimensions shown on plans) installed at(l5% minimum slope has capacity toconvey 2.74cfs. Bycomparison, the 1OO-yearflow calculated using the rational method is 1.907 cfs for the 0.648 acres of tributary area (conservatively modeled using the non roof tributary area to the mndtestormdrainaQe pipes with complete impervious coverage). The pipe has the capacityto convey onsiteflows. See calculations below. KHANNUHG'S EQUATION; 12"CPEPPipe @ 0'5%=2.7m4cfs m [l=1.48G/n* A * R 4p* S12 n=roughness coefficient =OJl12 A=cross sectional sreaofpipe=Tx(D/2)2=0.785 SF R=VVetted Perimeter ofPipe R 2/3 =(D/4)vs =0.397 S=slope 1m *z RATIONAL METHOD: Water Quality Area O =OA/cfd [= Runoff Coefficient (weighted average) C = 0.90for pavement and roofs [=U.25for lawns [Determination [=D.9Q|sconservative tothe nnsiteconditions |n =PeakRainfall |ntenoity=(a,*Tc-o')*P,=O.Q1Q*4.O=].27 a, =2.6l(10O-year) b, =O.6](1OO-year) lc = Time ofconcentration (6'3minutes minimum) P, =4.O(per isop|uvia|maps inKC3VVDK4) A ~Areo inAcres =0.64Qac Rational Method, Site�-oneoflowa: JOB #18-183 Technical Information Report 5.3 f i RATIONAL METHOD CONVEYANCE SYSTEM DESIGN LOCATION: KING COUNTY Fp(24RRRAINFALL): 4 INCHES PROJECT NAME: Bellwe3Iher TOD AparlmeaD PROJECT NUMBER: 18•183 PREPARED BY: JCR DESIGN STORM: IW YEAR LOCATION SIIBBASIN AREA (AC) "C" (A"CI SIIMOF (A"C) Tr (MINI la (INIIIR) Qa (CFS) M.ANNING'S I:" PIPE SIZE (IN) PIPE SLOPE (°) PIPE LENGTH (ET) ACTUAL V€LOCITY(VR) (EPISECI TRAVEL TIME (MIN) , PIPE CAP.ACIT ° SUMMARY QIPULL) (CPS) V(PIILLI (FTISEC) QalQ4FULL) 1%) FROM TO CBS CB4 0,132 0.77 0.102 0.102 630 3.27 0.334 0.024 12 6300 1S 3.33 0.38 4.844 6,17 6.00/ CB4 CB3 0.095 0.77 0.074 0.176 6.68 3.16 0.554 0.024 12 1.550 97 245 0.66 2403 3.06 23.1% CB3 MWS 0154 0.77 0.119 0295 7.34 297 0.877 0.024 12 1,060 141 2.44 096 1987 253 44.1°l MWS Vault 0.267 0.77 0207 0.501 8.30 2.75 1.380 0.024 12 5.500 27 5.01 0.09 4,526 576 30.5% Vault Pump 0738 077 0,571 1.072 839 273 2.931 0.024 12 1.290 39 219 0,23 2192 279 133.7/0 Pump CB 2 0000 0.777 0.000 1072 10.80 233 2.500 0024 4 1400 263 140 3.14 0.122 140 2049.9°% CB 2 CBI 0.000 077 0.000 1.072 10.80 2.33 2.500 0.024 12 2.020 20 3.95 0.08 2743 349 91.2% J 9 a J BACKWATER CALCULATIONS PROJECT NAME: BtlhvtathtrTODApartmtnis PREPARED BY: JCR PROJECT NI MBER: 18.183 DESIGN STORM: 100 YEAR PIPE SEGMENT Q ICES) PIPE LENGTH (FT) PIPE SIZE (IN) MANNING'S "n" VALUE OUTLET ELEVATION (FT) INLET ELEVATION (FT) PIPE AREA (SQ FT) FULL VELOCITY (FT/SEC) VELOCITY HEAD (FT) TAILWATER ELEVATION (IT) FRICTION LOSS (FT) ENTRANCE HGL ELEVATION (FTI ENTRANCE HEAD LOSS (FT) EXIT HEAD LOSS (FT) OUTLET CONTROL ELEVATION (FT) INLET CONTROL ELEVATION (8T) APPROACH VELOCITY HEAD (FT) BEND HEAD LOSS (8T1 JUNCTION HEAD LOSS (FT) HEADWATER ELEVATION (PT) RIM ELEVATION (FT) FREEBOARD (Frl FROM CB TO CB CB 1 CB2 2.50 20 12 0.024 32628 32650 079 3.18 016 32128 0.33 327.61 0.08 0.16 327.85 32750 0.00 0.13 000 327.97 329.75 178 Vault BioPod 1.38 27 12 0024 31600 316,79 079 176 005 320.21 0,14 320.35 002 005 320.42 31779 002 001 0,00 32041 322,28 1.87 BjoPod CB3 0.88 141 12 0,024 318,79 323,28 0.79 1.12 0.02 320.41 0.29 324.28 001 0,02 324.31 324,28 001 0,01 0,00 324.31 32528 0,97 CB 3 CB4 055 97 12 0.024 32320 326.37 0.79 0.71 0.01 324,31 0,08 32737 0.00 0.01 32738 32737 0.00 0,00 0,00 32738 32837 0.99 CB4 CBS 033 75 12 0.024 326.37 327.80 0,79 0.43 0.00 32738 0.02 328.80 0.00 0.00 328,80 328.80 000 0.00 0.00 328.80 329.80 1.00 EXCB;F119 RIM 335,68 if CONCiE 33441(E)s; S15NbSr 1RIBUTARY BASIN BOUNDARY LINE (TYP.) DETENTION VAULT TRIBUTARY AREA EXHiDIT EX CB ; 8086 TYPE I RNI332.46 - 12" CON IE 330.71(E) 'il1111111111111/_111Mrearagffiliq IIMUM MINNIMINEMi l� tip EX CB ;•:087 TYPE I N RIM 327.25 12' CONC IE 325.90 (W)- - - 12°DI IE 325.87 (E) I I SCALE: 1" = 40' 12" DHE 326,26 (E)?; 12" CONC SD �« Ir mirrin BioPOd o �o� u +lo D. J IIUEIINE N a h m e JOB NUMBER: 18-183 RGURE TA r • BELLWEATHER TOD APARTMENTS Section 6 Special Reports and Studies The following studies pertaining to this development are provided within the Appendix. • Geotechnical Report for the site prepared by PanGEO, INC. dated August 7,2017. JOB #18-183 Technic& Information Report 6.4 BELLWEATHER TOD APARTMENTS Section 7 Other Permits An Early Clear and Grade Permit will be applied for by the applicant. JOB #18-183 Technical Information Report 7.1 BELLWEATHER TOD APARTMENTS Section 8 TESC Analysis and Design See the project SWPPP submitted under separate cover. JOB #18-183 Technical Information Report 8.1 r BELLWEATHER TOD APARTMENTS Section 9 Bond Quantities and Facilities Summary A City of Tukwila Bond Quantity Worksheet will be included prior to permit issuance. JOB #18-183 Technical Information Report 9.1 irt BELLWEATHER TOD APARTMENTS Section 10 Operations and Maintenance An operations and maintenance manual will be provided prior to permit issuance. 10.1 JOB #18-183 Preliminary Technical Information Report FILE Mr. Jerry Hight, Building Official City of Tukwila Department of Community Development 6300 Southcenter Boulevard, Suite 100 Tukwila, WA 98188 MICHAEL NOUWENS Structural Consultants RE: The Confluence Apartments — Shoring at Storm Detention Vault RM File No. 262019.005/01401 Response to Plan Review — First Submittal Dear Mr. Hight: October 25, 2019 TD\°1- NOV 0 3 209 "(loon, uc6.011-toz_ REID MIDDLETO C. The following are our responses to the plan review comments related to the shoring at the detention vault and dated October 22, 2019: Geotechnical 1. MNSC response not required. 2. Please see General Shoring Notes on SH100 under "Inspection". This section discusses the geotechnical inspection requirements including pile hole drilling, lean mix installation and pile installation as well as the requirement to maintain records of soil condi • quantity of lean mix per pile. Structural Temporary Shoring 4. Please see attached calculations substantiating the design of the Iaggi Shoring Notes. 5. MNSC response not required. Please let us know if you require any additional information. Sincerely, Michael Nouwens Structural Consultants Michael L. Nouwens, SE LEED® Green Associate Enc. Structural calculations for shoring lagging EVI WEDF 0 R CODE COMPLIANCE APPROVED NOV 15 2019 Indicated in the General City of Tukwila BUILDING DIVISION P. O. 13 0x 921 • EDMON ID s, WA 98o2o • p: 206 5 4 6 8 4 4 6 • e: michael@nouwens-structural.com BELLWETHER TUKWILA APARTM ENTS SHORING STRUCTURAL CALCULATIONS 09-30-2019 SHORING PERMIT SUBMITTAL 10-25-2019 RESPONSE TO CORRECTION NOTICE 1 10-25-2019 M I C H A E L NO U W E N S BELLWETHER TUKWILA APARTMENTS 10-25-2019 Structural. Consultants PROJECT 305 NW 178th Street JOHNSON BRAUND INC. Shoreline, WA 98177 michad@nouwens•stru tural,com CLIENT www.nouwens-structural.com P 206546.8446 DATIE NO. KILN COVER DESIGN SHEET 0 CZ. •# I 0 -7.go le tco I.- ,Ate.6) • - • • 4•0 w geo,5-0 /5..t5 it.V5 ze#77 401 cf0° * 2,- - -L 0.4-2/a Ce,3 P5.47.(•- - A t • • .1. 1.5 t • • + r a v.05-fi z -.-174. (#0 • 410 P1vit-0.5vs. 12.4* A .5t) /I, z t • —e• CHAEL NOUWENS e;:,e)44. Structural Consultants PROJECT 30 5 NW 1 7 8th ST Shoreline, WA 98177 michaeltenouwens-structursicom CLIENT www.nouwerts-structuralcom P 206.546.8446 10/z5-,, DATE NO. MLA/ / DESIGN SHEET let/ave.- +et /5f- alutedwit ritr 4-7tiz., HP F4 14-9'60 -- F I , "r5F 41, isv tit 2* -a. 0.0 0 • — • 23,4 . . r, /, / -a. - 2 fro 2Z/ 14 015,41$ • • ••• - • • -4- ••.^ .40 • 4 4, • /4 4 - • . 4 01 1,44 + - +so, /2 HAza- - — t - 4 ICHAEL NOUWENS /50144ee -1-4-0/7si /0 Structural Consultants PROJECT 305 NW 1 78th ST Shoreline, WA 98177 michaeleriouwerts-structuraLcorn CLIENT www.nowarens-structurad.com P 206.546.8446 DATE NO. DESIGN SHEET bet00151- 4. /, aviec4m ••••••..,- September 12, 2019 PanGEO Project No. 17-1 MLODLETQN, INC. Ms. Emma Geyer Bellwether Housing 1651 Bellevue Avenue Seattle, Washington 98122 Subject: Temporary Shoring Recommendations Proposed Confluence Apartments: 3703 South 152nd Street, Tukwila, WA FILE PanGE® INCORPOR *TED Geotechnical & Earthquake Engineering Consultants Oo 2019 Vp2ofi.ciz6.a\t\oL REID ivilDDLELN, INC. Dear Ms. Geyer: As requested, PanGEO, Inc., is pleased to present this letter providing temporary shoring recommendations for the proposed Confluence Apartments at 3703 South 152nd Street in Tukwila, Washington. We previously prepared a geotechnical report for this project dated August 7, 2017. This letter references subsurface information and recommendations presented in our geotechnical report. As such, it should be used in conjunction with that report. PROJECT BACKGROUND The subject site is located at 3703 South 152nd Street in Tukwila, Washington. The site consists of three rectangular shaped parcels that comprise a combined area of about 52,572 square feet. At the time of our August 7, 2017 geotechnical report, it was planned to develop the site with a seven -story building with a half level of below grade parking. At this time, we understand it is planned to provide a full level of below grade parking. The excavation for the below grade parking will extend to a depth of about nine to 13 feet below grade and will encroach to within 10 to 11 feet of the north property boundary. Additionally, it is planned to construct a below grade stormwater detention vault in the south portion of the site that will require making an excavation that extends to 12 to 14 feet below grade that encroaches to within about 10 feet of the south property line. Subsurface conditions at the site consist of a surficial layer of loose to medium the entire site. We encountered recessional outwash, comprised of medium i5gFOR MPCIANCE APPROVED NOV 1 5 2019 City of Tukwila Temporary Shoring Recommendations Proposed Confluence Apartments: 3703 South 152"d Street, Tukwila, Washington September 12, 2019 gravel gravel below the fill in the north portion of the site. The south portion of the site is underlain by Vashon till comprised of medium dense to very dense silty sand with gravel. At the time of our August 7, 2017 report, it was anticipated the excavation would be accomplished as a conventional open cut with temporary slopes. At this time, due to the depth of the excavation and the proximity of the excavation to the surrounding property lines it appears temporary shoring will be needed to support the portions of the excavation. The purpose of this letter is to provide recommendations for temporary shoring design. TEMPORARY SHORING RECOMMENDATIONS Temporary shoring options that would be applicable to this project include gravity walls, such as Ultrablocks and cantilevered soldier pile walls with timber lagging. ULTRABLOCK WALL SHORING Ultrablocks consist of concrete blocks measuring 21/2 feet high by 2'/2 feet wide by 5 feet long. The blocks have a cross -shaped key cast into the top of the blocks and a corresponding keyway in the bottom of the blocks. The blocks can be stacked to create a gravity wall shoring system, in which the mass of the wall is used to support the retained soils. Based on the encountered soil conditions, in our opinion, Ultrablocks can be used to shore an excavation with a maximum height of two blocks, or 5 feet, with a vertical face. A gravity wall up to three blocks, or 7'/2 feet high, may be constructed, but would need to have a face batter of no steeper than 6V:1H (Vertical:Horizontal). The blocks should be placed in a running bond pattern and the space between the blocks and excavation backfilled with clean crushed rock meeting the requirements for Permeable Ballast in the WSDOT Standard Specifications, Section 9-03.9(2) (WSDOT, 2018,lor an approved equivalent. Clean rounded gravel such as pea gravel or washed gravel/drain rock should not be used to backfill the block walls. The block wall shoring may be placed in alignment with the basement walls of the building and may be used as the back form for the permanent basement walls. The joints between the blocks will allow groundwater to seep through the shoring. As the wall will be faced by the concrete basement walls, it will be necessary to provide drainage to collect the seepage and prevent hydrostatic pressures from building up behind the wall and concrete facing. For this application, a geocomposite sheet drain incorporating a fiker fabric such as 17-211.20.0 Temporary Shoring 2 PanGEO, Inc. Temporary Shoring Recommendations Proposed Confluence Apartments: 3703 South 152" Street, Tukwila, September 12, 2019 on Miradrain 6000, or equivalent, should be used. The sheet drain should connect to piping extending through the basement wall that connects to a collector pipe that extends around the inside perimeter foundation. The following additional recommendations should be incorporated into the Ultrablock shoring design and construction: • The slope above the wall (backslope) should be no steeper than 1H:1V for a maximum height of 8 feet. The grade at the base of the wall (foreslope) should be level. • The bottom course of a one- or two -block wall may be placed on grade. The bottom course of a three -block high wall should be embedded at least one foot below the construction subgrade elevation. • The blocks should be stockpiled on -site before excavating for the wall alignment. • Blocks shall be placed immediately after the cut is made, otherwise the cut face shall be buttressed with on -site soils until the blocks can be placed. • The width of unsupported cut face for block placement shall be limited to no more than about 12 feet at any given time. If the excavation cannot be accomplished using Ultrablock shoring, then cantilevered soldier piles with timber lagging shoring should be considered. TEMPORARY CANTILEVERED SOLDIER PILES WITH TIMBER LAGGING SHORING Where unsupported open cuts or Ultrablock shoring walls are not feasible, solider pile walls may be considered to support the excavations. A cantilevered soldier pile shoring wall is typically used for a wall height with up to about 12 to 14 feet of vertical exposed face. If wall heights of greater than 12 to 14 feet are being considered, then shoring incorporating tiebacks may be more economical. We can provide recommendations for shoring incorporating tiebacks, if needed. Soldier pile shoring consists of vertical steel beams, typically installed 6 to 8 feet apart around the perimeter of excavation, spanned by timber lagging. Prior to the start of excavation, the steel 1-1- beams are installed in pre -drilled holes that are backfilled with structural concrete and/or lean mix concrete. As the excavation proceeds downward and the steel piles are exposed, timber lagging is installed between the flanges of the H-beams to support the soils exposed in the excavation. The basement walls may then be formed and cast directly against the shoring. 17-211.200 Temporary Shoring PanGEO, Inc. Temporary Shoring Recommendations Proposed Confluence Apartments: 3703 South 152'd Street, Tukwila, Washington September 12, 2019 Wall Design Parameters The earth pressures depicted on Figure 1, Design Lateral Pressures, Cantilevered Soldier Pile Wall should be used for design. The lateral earth pressures should be increased for surcharge loads resulting from adjacent structures, traffic, construction equipment, or excavated soil stockpiles if they are located within the height dimension (H) of the wall. Recommendations for surcharge loads are provided on Figure 1. Above the bottom of excavation, the recommended active earth and surcharge pressures should be applied over the full width of pile spacing. Below the bottom of excavation, the active pressures should be applied over one pile diameter, and the passive resistance should be applied over two times the pile diameter. The upper two feet of the passive pressure should be neglected to allow for disturbance of the ground surface in front of the wall. Lagging Lagging design recommendations are presented on Figure 1. Voids between the timber lagging and excavation face should be backfilled with control density fill (CDF). Drainage The joints between the lagging will allow groundwater to seep through the shoring. A geocomposite sheet drain incorporating a filter fabric such as Miradrain 6000, or equivalent, should be used to collect seepage and prevent hydrostatic pressures from building up behind the wall and concrete facing. The sheet drain should connect to piping extending through the basement wall that connects to a collector pipe that extends around the inside perimeter foundation. The timber lagging may be designed for 50 percent of the recommended lateral earth pressures, to account for the effects of soil arching. BASELINE SURVEY AND MONITORING Ground movements will occur as a result of excavation activities. As such, ground surface elevations of the adjacent properties and structures should be documented prior to commencing earthwork to provide baseline data. As a minimum, optical survey points should be established at the following locations: The top of every other soldier pile or a horizontal spacing of 15 feet for Ultrablocks. These monitoring points should be monitored twice a week during excavation. The monitoring frequency may be reduced based on the monitoring results. I 7-211,200 Temporary Shoring 4 PanGEO, Inc. Temporary Shoring Recommendations Proposed Confluence Apartments: 3703 South 152nd Street, Tukwila, Washington September 12, 2019 Adjacent structures located within 25 feet of the shoring walls. The curbs and the centerlines of adjacent streets should be monitored by establishing a set of baseline point spaced no more than 20 feet apart. These monitoring points should not need to be regularly surveyed after the baseline is established unless the soldier pile wall monitoring indicates deflections exceeding one inch. The monitoring program should include monitoring for changes in both the horizontal (x and y directions) and vertical deformations. The monitoring should be performed by the contractor or the project surveyor, and the results should be promptly submitted to PanGEO for review. The results of the monitoring will allow the design team to confirm design parameters, and for the contractor to make adjustments if necessary. We also recommend the existing conditions along the public right of way and the adjacent private properties be photo -documented prior to commencing earthwork at the site. CLOSURE We trust this information meets your current needs. If you have any questions, please contact our office. Sincerely, PanGEO, Inc. Scott D. Dinkelman, LEG Senior Engineering Geologist leozo Michael H. Xue, P.E. Senior Geotechnical Engineer Attachment: Figure 1 Design Lateral Pressures, Cantilevered Soldier Pile Wall 17-211,200 Temporary Shoring 5 PanGEO, Inc. Street Traffic Surcharge: 80 psf uniform pressure Aooly onlyto above bottom of excavation Notes; 1. Active earth pressures assume shoring is fully drained and hydrostatic pressures are not allowed to develop behind the shoring. 2. Minumum embedment should be at least 10 feet below bottom of excavation. 3, A factor of safety of 1.5 has been applied to the recommended passive pressure values. No factor of safety has been applied to the recommended active earth pressure values. 4. Active pressures should be applied over the full width of the pile spacing above the base of the excavation, and over one pile diameter below the base of the excavation. 5. Surcharge pressures should be applied over the entire length of the loaded area. 6, Passive pressure should be applied to two times the diameter of the soldier piles. 7. Use 50% of the active and surcharge pressures for lagging design with soldier piles spaced at 8' or less. 8. Refer to report text for additional discussions. 1 0.4(1 xIH) q 3B, a Footing Surcharge Apply o ly to above bottom of excavation Footing Surcharge B, X Level Backslope 1- 1H:1VTemporary Cut (if applicable) Soldier Pile Wall with Timber Lagging Base of Excavation 45 pcI t1 H:1V backslope) 35 pcf (level badcslopel 350 pot Active Pressure Passive Pressure H PanGE® i l t O l P Q I A T E o The Confluence Apartments 3703 South 152nd St Tukwila, Washington DESIGN LATERAL EARTH PRESSURES CANTILEVERED SOLDIER PILE WALL Prof ecl No. 11.211.10e Figure No. 0 0 • • " 10' - 0" MIN - F-111-r7.111-FIIFT-r111 I DESIGN TBD--1--11 III Ultrablock, 2.5'H x 2.5'W x 5'L Nol:e: Modified from North Excavation Sections by Johnson Braund, August 30, 2019 APPROX HI( WEST EDGE SOUTH PROI 324.09. 4•••••••••PR *IP Approx. Scale (feet) 0 2.5 5 PanGE® I 'ICOR POR ATIO Bellwether Affordable Apartments 3703/3705/3481 So 152nd St Tukwila, WA ULTRABLOCK TEMPORARY SHORING Project No. 17.211 Figure No. x BELLWETHER TUKWILA APARTMENTS REVI CODE COMPLIANCE APPROVED NOV 15 2019 City of Tukwila UIL ING DIVISION RE 4 • V NOVLj 2019 voDDLETON, INC. HORING STRUCTURAL CALCULATIONS RING PERMIT SUBMITTAL blq 03i7 micanral cr-cv 0E4 vLfittasiva SEP 30 2019 PEKEVC7c,:r7FiLi 9-26-2019 M I C H A E L NO U W E N S BELLWETHER TUKWILA APARTMENTS 9-30-2019 Structural Consultants 305 NW 178th Street Shoreline, WA 98177 michael@nouwens-structurai.com www.nouwens-structural.com P 206.546.8446 PROJECT JOHNSON BRAUND INC. CLIENT DATE MLN NO. COVER DESIGN SHEET Depth(ft) -" 5 10 -15 -20 25 V L Bellwether Affordable Apartments 1ksf J Moment Equilibrium f�orce Equilibrium <ShonngSulte> CIVILTEC*aoFTWARE USAwwwmiviltech.com Licensed to 4324324234 3424343 Dote:9/24/2019 File: C:\Jsers\MikeNouwmn ments\1 MNSC Project Oucumonts\Be|kwethorTuhwila\ua|cu!aUons\S'uhohng\Ci - �Ri|eDiomebeF=2.5 Pi|eGpocing=7.5 Wall Type: 2. Soldier Pile, Drilled P|LELENGTH:Min. Embedmwnt=18.75 Min, Pile Langth=32.0D(in graphics and analysis) User inputted Embadmont`2O.OD. R|oLength=35.25 MOMENT |NPILE: Max. yNommnt=325.38 per Pile Gpmcing=7.5 stOe[th=22.48 SYSTEM FACTOR OF SAFETY (Approximmtm)=1.1& The request embedment io1G7.the user input fixed embedment =2O. PILE SELECTION: Request Min. Section Modulus =118.3in3/pi|e=1838.S4om3/p|e.Fy=5Uksi=345K4Pa. .GG VV21X93 has Section Modulus = 192.0 in3/ple=3148.30 cm3/pUe. |timgreater than Min. Requirements! DRIVING PRESSURES (AC3lVE.WATER, &8URCHARGE): O O 35.25 1.23 0.034894 PASSIVE PRESSURES: z1 P1 � 17.25 .70 85.25 ' 7D0 l[3500 ° ACTIVE SPACING: No. 1 2 PASSIVE SPACING: No. 1 �AIw 22 P2 ~ ~OF Zdopth Spacing 0.00 7.50 15.25 2.50 Zdapth Spacing 16.25 5.00 UNITS: Width, Spacing, Diameter, Length, and Depth - ft; Force - kip; Moment - kip-ft oepth(ft) -" -1V -15 -20 -25 � -35 Bellwether ����^�����&�U Apartments ����n�������������nn��n��x�w�n�� ��8�puo*nnnA�on�� O 1msf Moment Equilibrium Force quilibrium <ShoringSuue> CIVIoECH SOFTWARE USA www.ciwltech.com Licensed to 4324324234 3424343 Data:9/24/2019 File: C:\Ueers\MikeNouwenm\Dropbox\Dooumenb\1 yWNSCProject Documenb\BdkwedharTuhwi|a\ua|uu|uUons\S'mhohng\Ci Wall Height=13.3 Pile Diameter=2.5 Pile Spacing=8.0 Wall Type: 2. Soldier Pile, Drilled PILE LENGTH: Min. Embedment=17.06 K4hm. Pile Length=30.31 (in graphics and analysis) User inputted Embedment=1&OO. PUeLength=32.25 MOMENT IN PILE: Max. Moment=324.88 per Pile Spacing=8.0 at Depth=20.76 SYSTEM FACTOR {]FSAFETY (Appn»xmebe)=1.11 The request embedment is 17.1, the user input fixed embedment = 19. PILE SELECTION: Request Min. Section Modulus =118.1in3/pika=1935.92 cn3/ni|e.Fv=50kni=345&1Pa.Fb/Fv=8.66 VV21X73has Section Modulus =151.0in3/pi|m=2474.44om3/piUm.|tiogreater than Min. Requirements! Top Deflection =O.96(in)based on E(kui)=29OOO.O0and |(in4)/pi|e=180O.0 DRIVING PRESSURES (ACTK/E.WATER, &SVRCHARGE): O 0 32.25 1.451 0.044992 PASSIVE PRESSURES: ACTIVE SPACING: No. 1 2 PASSIVE SPACING: 1 Zdepth Spacing Z depth Spacing UNITS: Width, Spacing, Diameter, Langt .andDapt -ftFonca-kip;YNomant-Wp-ft ��u�U Affordable Apartments ����oU�����U������nn"�n~���m�o�� ��K�"mn�novK�"o�� Pile P7 (P2 siN0) Depth(ft) -" 10 15 20 o 1hsf _30 R, Moment E^uilibhum Force Equilibrium *aho,mgauum> om/Lrsc*SOFTWARE USA vmww.c*ote,o.cnm Licensed to 4324324234 3424343 Date:9/24/2019 File: C:\Unens\MikeNmuwen ments\1yNNSCProjeutOooumenbs\BakwethevTuhwila\oalcu1mtionm\0'ohohng\Ci Wall Height=1 1 O Pile Diameter=2.5 Pile Spacing=8.0 Wall Type: 2. Soldier Pile, Drilled PILE LENGTH: Min, Embodment=14.34 Min. Pile Length=25.34(in graphics and User inputted Enbudmunt`1G.0\ Pi|aLengUh=27.00 MOMENT |NPILE: Max. yNomont=18O.TS per Pile Gpadng=8D a1Oepth=17.3T SYSTEM FACTOR OFSAFETY 1.12 The request embedment is 14.3, the user input fixed embedment = 16. PILE SELECTION: Request Min. Section Modulus =G84in3/pi|e=1138.91cm3/pUm.Fy=5Oksi=345yWPm.Fb/Fy=O.GS VV18X5Ohas Section Modulus =88.9in3/pUo=1456.8Oom3/pika. Itiagreater than Min. Requirements! DRIVING PRESSURES (ACT|VE.WATER, &SURCHARGE): 0 0 27 1.315 0.045000 PASSIVE PRESSURES: ACTIVE SPACING: Spacing 1 2 PASSIVE SPACING: 1 Zdepth 11.00 8.00 UNITS: Width, Spmnn0.Diamebar,L*ngUh.andDepth 'ftForce -Np;Moment 'kip-ft SITE STRUCTURES A Division of Kosnik Engineering, PC Bellwether TOD Apartments Storm Water Detention Vault City of Tukwila, Washington Structural Calculations Project No. S-19-068 First Issue 08-12-19 Revised 09-24-19 10505 19TH Ave SE, Suite B, Everett, WA 98208 ♦ (425) 357-9600 (phone) ♦ e-mail: dan@kosnik.com Bellwether TOD Apartments Storm Water Detention Vault Project No. S-19-068 STRUCTURAL CALCULATIONS INDEX Sheet Design Criteria 01 - 04 Lid Review 05 - 10 Wall & Footing Design 11 - 18 Framing @ LW Hatch Opening 19 - 24 ,S11-E-Er I Bellwether TOD Apartments Storm Water Detention Vault DESIGN CRITERIA Code: 2015 IBC Permitting City of Tukwila Soil Cover: 0.83ft min to 3.48ft max S- • Olig Lid Loading: 150 psf uniform live load HS20 truck wheel loading GVW= 72,0001bs Fire truck wheel loading GVW=70,0001bs Fire truck outrigger load 45,0001bs over 18" sq pad Uniform live load does not act concurrently with truck wheel or outrigger loading. Hatch: HS 20 rated solid hatch. Foundation Design: Foundation design is based on the following values provided by PanGEO in their report dated 08-07-17 Allowable Bearing Pressure: 4,000 psf Lateral Earth Pressures on Vault Walls - Drained level backfill condition: Active: 35 pcf EFW At Rest: 45pcf EFW Seismic Addition: E =8H psf Uniform Saturated Soil Density: 125 pcf Material Requirements: Rebar: Grade 60 Concrete: fc= 4000 psi walls, f c=3000 psi footings & grade slab Lid: Pre -cast, Pre -stressed Hollow Core Plank 12-1/2" thick. SITE STRUCTURES Project !�' ELLCR, sheet o7 date $ - ► a -11 FRONT AXEL: REAR AXEL #2: 14 yL Vei+¢rtb ` 8;000 lb HS24-44 3 000 ib 6.000P3 K515-44 24.000 lb 0.4W HS20-44 72,000LBS Some *6 G H-trluek W s two oxles V ■ 4or Bo ! & Sp4rGing Wh1CA produCeS moxirrnrm stte65 For design of slabs, center V wheel to be 1 ft from curb prj.no. s•q-ass HS25-44 90,OOOLBS 10,000LBS 40,,000LBS 40,00.OLBS nchn 0614Pipv17kvc) � Rh hD wN� � Nao ‘.4 - Overall length: 48 feet 10 inches Overall height: 11teet 4 inches Point load for outriggers: Angle of approach/departure minimum: 9 degrees Mininium front clearance from ground: 18 3'4 inches Minimum rear clearance from ground: 16 inches Minimum center of vehicle clearance: 15 Ya inches ( 1110 \\\\\\\\\\ 0 0 252' (21' -586" (4810') NO 1483/8" (12' 4 Ye} -EX (501. 14" added lor Duffer 4') \\\\\\\\\\ 0 0 252' (21' -586" (4810') NO 1483/8" (12' 4 Ye} -EX (501. 14" added lor Duffer 4') 0 44 TRUCK LIVE LOAD ON WALLS hkil 4 • 9 • do, • • • • • • w t • • 0 (, 100 ' #t� 200 ' 300 AVERAGE UNIFORM HORIZONTAL L©A' 5-19-ocniE `11 • 400. , .. SITE STRUCTURES Project Bellwether sheet 10511 19th Ave SE, Suite C date Everett, WA, (425)-357-9600 prj. no. S-19-068 PRECAST HOLLOW CORE PLANK REVIEW Lid Data Soil Desity Soil Cover depth over lid Plank design clear span Design Uniform Live Load Design Superimposed Load 125 pcf 3.48 ft 15 ft 150 psf 585 psf Plank capacity based on uniform superimposed load tables Plank span No of tendons Allowable superimposed loads 28 ft 11 Allowable superimposed loads base of design span of Based on flexural capacity Based on shear capacity Plank capacity based on truck load charts 413 psf 15.25 ft 1392 psf 758 psf Plank span No of tendons Allowable soil cover without knee -walls Allowable soil cover with knee -walls 15.25 ft 11 NA ft 0 83 to 11.5 ft t7-61,1) (.01ip _6bederlig_ s-o-i9 sc-19-0(4 121/2" HOLLOW CORE SLAB DIMENSIONS FOR DETAILING (4!-O" Nominal Width) SPAN -LOAD TABLE ALLOWABLE SUPERIMPOSED LOAD In pounds per squaro foot Effective . Prestress (KIPS) No. of 1/2" 0 STRANDS SIMPLE SPAN In feet 28 32 36 40 44 48 52 56 50 70.7 77.7 101.3 124.8 148.4 172.0 195.5 219.1 242.7 3 4 5 6 7 8 9 10 11 78 126 174 221 267 307 343 3781 4131 44 80 117 153 186 216 243 270 297 20 49 78 106 129 153 174 , 195 217 26 50 70 89 108 125 142 160 27 43 59 74 89 103 117 23* 86 49 61 73 85 29 40 50 60 23* 31* 40 24* SECTION PROPERTIES (with shear keys grouted) A = 313 in2 I = 6136 irt4 Zt = 1019 in3 Yt = 6.02 in Zb = 947 in3 Yb = 6.48 in w = 84 psf NOTES: 1. The values given in this table are based on hollow core slabs without shear reinforcement. SupersCripts (1, 2, etc.) following values in the table Indicate the number of filled voids required at the ends of slabs to develop the allowable superimposed toad. See page 2, `'SHEAR" for discussion. 2. Asterisk (*) following values in the bible Indicate that the total deflection under all loads is greater than U360 but lass than U180. 3. Interpolation between values is acceptable: Do not extrapolate values into the blank spaces of the table. 4. These Span -Load Tablet are intended as an aid -to preliminary sizing. Sound engineering Judgement is required for the application of this information to specific design cases. CONCRETE TECHNOLOGY CORPORATION 121/2" HOLLOW CORE SLAB 45 KIP OUTRIGGER ON 18"x18" PADS @ 151-0" O.C. 12 11 q 10 u . 9 a. 0 ▪ 8 11 cn • 7 6 O 5 o 4 u. 0 • 2 0 iNKIIN iklwnwi El I iSAIIIIIIIII IIII ivuhalursi ikom• Nifilmi rirrI ,. Number= of Filled Voidsrequiredba ilsslab. 2111111101 1 1 a,\11-‘1 for0 a each t end each . 111111 IN ZIrp- 11 Strands 111111 III 1111EIM = 1111111111111111111 .s.,‘:;\,\,,, , I i..1...i.i717:17=;.25pcfj.., IIEN PP' 11 ow ' ill _... - raigill.4 14 GENERAL NOTES: 1.) A minimum cover depth of nine inches is required. 2.) Simple Span is centerline of bearing to centerline of bearing. 3.) Knee walls are required at all manhole and vent openings. 4.) Interpolation between strand contours is acceptable. DO NOT extrapolate beyond the bounds of this chart. 5.) Soil cover is assumed to be uniform. 6.) Except as noted, soil cover unit weight is assumed to be 120 pcf. 7.) Minimum span length = 14-0". 8.) The values shown on this chart are in compliance with IBC 2015 & ACI 318-14. 18 20 22 24 26 28 30 SIMPLE SPAN (ft) 32 34 36 38 13-ic2-i S - I 41 -otoS 1/17/17 MANUFACTURERS OF PRESTRESSED CONCRETE • TACOMA, WASHINGTON 11 SOIL = 120 PCF U.N.0 12 11 10 Q 8 7 8 i U ������K��T��O������������������ ���U�����L |L�U|������| ���|����|��|� ���"��d�U �����U�� u^�^� "x��"~~.�*m� ���*"�~~ ���.��"� ������-�� """���-�� 05,1101 IMM N � k, kh N irs I Elmmm M EMNI INE 0 01 106411 ON 1010=10 k1i5awor No NNE 11 14 It # Number of Filled Voids required for 7-0" at each end of each slab. '-peli ON 0 Vent Notch9 �dl tirm ki kk Knee -010 R JENSEN . OMEN z W a 0-M mr, 24:0-00 M= Mao 0 FA SHEMESSION 14 �� �v GENERAL NOTES: 1. /\ minimum cover depth rfsix inches ORathree inch thick cast inplace concrete topping slab isrequired. 2.Simple Span iocenterline ofbearing hocenterline ofbearing. 3.) The Knee Wall envelope represents the maximum span and height of soil cover that can be supported by slabs with standard notches for manhole openings, assuming void O|| concrete yo= 3.000 poi. Points failing outside this envelope require knee walls hosupport the slabs otmanhole openings. 4. Interpolation between strand contours is acceptable. DO NOT extrapolate beyond the bounds of this chart. 5.)Soil cover iuassumed tobouniform. 6.Except aonoted, soil cover unit weight ioassumed tobe12Opof. 7. Minimum span length = 14/'0^. 8.The values shown onthis chart are incompliance with IBC 2U15&AC|318-i4. 9.) The Vent Notch envelope represents the maximum span and minimum/maximum height of soil cover that can besupported byslabs with 61/2.'standard notches |nadjacent slabs toaccommodate i2"diameter vents, assuming void fill concrete f c = 3,000 psi. Refer to Detail 3 on page 13 of this brochure for vent notch details. 0-ld SIMPLE SPAN (ft) 36 38 1m3/17 MANUFACTURERS OFPRESTRESSED CONCRETE °TACOMA.VVASHIyJGTON 8 (YsolL = 120 PCF U.N.O HEIGHT OF SOIL COVER 12 11 10 8 7 6 4 2 0 14 T16 CONCRETE TECHNOLOGY CORPORATION 121/2" HOLLOW CORE SLAB HS20-44 ... ..... ..... is:rims:1 VIVE111111111 1111 IIIII1_ 11111111111111 II m11E111111 WWII •aakli,t011111111 imummornmi 1 ri \aV , # = Number of Fil ed Voids required di k for 21-0" at each end of each slab. 1 i I I ri • 11 II 1 I Vent Notch9 i. • 1 \ ._ „fill 11 Strands ,...... Strands (ywn = 125 pcf) I I\ : /111 Strands (yson = 135 pcf) IIhb... 11 Knee 11111111J1 1Wall3 -jou I - I11111111 8 20 22 24 26 28 30 32 34 36 38 SIMPLE SPAN (ft) 9 5-41- 0(4 , GENERAL NOTES: 1.) A minimum cover depth of six inches OR a three inch thick cast in place concrete topping slab is required. 2.) Simple Span is centerline of bearing to centerline of bearing. 3.) The Knee Wall envelope represents the maximum span and height of soil cover that can be supported by slabs with standard notches for manhole openings, assuming void fill concrete f'c = 3,000 psi. Points falling outside this envelope require knee walls to support the slabs at manhole openings. 4.) Interpolation between strand contours is acceptable. DO NOT extrapolate beyond the bounds of this chart. 5.) Soil cover is assumed to be uniform. 6.) Except as noted, soil cover unit weight is assumed to be 120 pcf. 7.) Minimum span length = 14'-0". 8.) The values shown on this chart are in compliance with IBC 2015 & ACI 318-14. 9.) The Vent Notch envelope represents the maximum span and height of soil cover that can be supported by slabs with 61/2" standard notches in adjacent slabs to accommodate 12" diameter vents, assuming void fill concrete f'c = 3,000 psi. Refer to Detail 3 on page 13 of this brochure for vent notch details. 1/03/17 MANUFACTURERS OF PRESTRESSED CONCRETE • TACOMA, WASHINGTON 7 (7sou. :2 120 PCF U.N.0 12 10 g 7 O LLl 5 5 4 �LL 3 O CONCRETE TECHNOLOGY CORPORATION ���o ��d�U �~���� SLAB "u��� uu��x~x~�*�� �~��o�m~ ���� ��� "�= " `�" MMEM | / / / / / VantNo�huSo � = Number of Filled Voids required 14 SIMPLE SPAN (ft) 32 34 36 38 6'/�Q-19 5-11-av� GENERAL NOTES: 1. Aminimum cover depth of six inches OR a three inch thick cast in place concrete topping slab is required. 2.)Simple Span iocenterline ofbearing 0ocenterline cfbearing. 3.) The Knee Wall envelope represents the maximum span and height of soil cover that can be supported by slabs with standard notches for manhole openings, assuming void fill concrete f c = 3,000 psi. Points falling outside this envelope requireknee walls tosupport the slabs mtmanhole openings. 4.) Interpolation between strand contours is acceptable. DO NOT mn1nopo|ata beyond the bounds of this chart. 5.)Soil cover iuassumed tmbeuniform. S Except aonoted, soilunit weight iaassumed tobo12OpoC T Minimum span length =14''O^. The values shown onthis chart are |ncompliance withIBC 2O15&AC|318'14. 9.) The Vent Notch envelope represents the maximum span and height of soil cover that can be supported by slabs with G1/2!standard notches inadjacent slabs toaccommodate 12^diameter vents, assuming void fill concrete fc= 3,000 psi. Refer to Detail 3 on page 13 of this brochure for vent notch details. 1m3117 MANUFACTURERS {]FPRESTRESSED CONCRETE °TACOMA'VYA3H|NGTON 9 SITE STRUCTURES Project Bellwether sheet: i 10511 19th Ave SE, Suite C date: Everett, WA, (425)-357-9600 prj. no. S-19-068 Vault Walis - Lateral Pressures Review Minimum soil cover depth to top of wall: Maximum soil cover depth to top of wall: Wall Height: At -Rest soil pressure: Active soil pressure: Uniform Addition to At -Rest soil pressure: Soil Density: Load Combinations: 1.6 L (soil pressure) + 1.6 L (soil pressure) + Due to HS25 Truck Loading: 0.8 ft min cover over lid: 3.4 ft max cover over lid: Total Factored Lateral Force: 0.8 ft min cover over lid: 3.4 ft max cover over lid: Due to Uniform Surcharge Load: Uniform surcharge: Equivalent lateral force: 1.83 ft 4.38 ft 8.08 ft 45 pcf EFD 35 pcf EFD 0 psf 125 pcf 1.6 L (surcharge/wheel load) 1.0 L (seismic) 173 psf Uniform 73 psf Uniform 5651 plf 5842 plf 150 psf 54 psf Uniform Total Factored Lateral Force: 3.4 ft max cover over lid: 5597 plf Due to Seismic Activity: Uniform seismic addition: E = Seismic lateral force: Total Factored Lateral Force: 3.4 ft max cover over lid: Combined Load Factor: 8 H 65 psf Uniform 4332 plf 1.53 SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Design Data Soil Density Soil Cover depth to the top of the wall Wall height Soil Pressure EFW Surcharge Information Project Bellwether 125 pcf 4.48 ft 8.08 ft 45 pcf sheet 102 date prj. no. S-19-068 5v11-60P1a. Ws1 = Ws2 = 201.6 psf 363.6 psf uniform Si = truck Ws = 150 psf (on surface of ground) Equiv Ws = 73 psf ( on surface of wall - see design chart ) Critical Design Surcharge pressure = Calculated Design Forces 73 psf (on the surface of the wall) 54 psf W1= 274.6 W2= 363.6 M1 = 2241 M2 = 1523 Wall Reinforcing F1 = 2218.768 Ibs F2 = 1468.944 Ibs M total= 3764 ft-Ibs R top = R bot = 1599 Ibs 2089 Ibs Wall thickness 8 inches Clear cover 2 inches Rebar size 5 Rebar area 0.31 sq-in Bar spacing 12 inches Rebar strength fy 60 ksi Conc strength fc 4000 psi Load Factor 1.6 max tension reinforcing spacing: Anchorage at Top of the Wall Comp block (a) = Depth to CL bar (d) = d-a/2 = 26954 psi (I)Mn = Mu = S= s= smax = 0.45 inches 5.69 inches 5.46 inches 7540 ft-Ibs 6022 ft-Ibs 17.3 in 17.8 in 17.3 in - OK Ru = 2558 plf #5 hairpins net #5@ 15"o/c #5 hairpins net #5@ 18"o/c Anchorage at Bottom of the Wall 4:Nn = 6700p1f ciA/n = 5580p1f Ru = 3342 plf Nominal Shear friction capacity of the footing to wall Dowel 9486 plf Rebar Dowel Size = Dowel Area = Dowel strength fy= Dowel Spacing = Coefficient of friction = 5 0.31 sq-in 60 ksi 12 inches 0,6 smooth surface SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Design Data Soil Density Soil Cover depth to the top of the wall Wall height Soil Pressure EFW Surcharge Information Project Bellwether sheet 13 /oT 125 pcf 4.48 ft 8.08 ft 45 pcf date g- 102-19 prj. no. S-19-068 41ip-e4A-1\-e•S Ws1 = Ws2 = 201.6 psf 363.6 psf uniform Si = truck Ws 0 psf (on surface of ground) Equiv Ws = 0 psf ( on surface of wall - see design chart ) Critical Design Surcharge pressure = Calculated Design Forces 0 psf (on the surface of the wall) 0 psf W1= 201.6 W2= 363,6 M1 = 1645 M2 = 1523 Wall Reinforcing F1 = 1628.928 Ibs F2 = 1468.944 Ibs M total= 3168 ft-Ibs R top = R bot = 1304 Ibs 1794 Ibs Wall thickness 8 inches Clear cover 2 inches Rebar size 5 Rebar area 0.31 sq-in Bar spacing 12 inches Rebar strength fy 60 ksi Conc strength fc 4000 psi Load Factor 1.6 max tension reinforcing spacing: fs = Anchorage at Top of the Wall Comp block (a) = Depth to CL bar (d) = d-a/2 = 22687 psi 0.45 inches 5.69 inches 5.46 inches (1)Mn = 7540 ft-lbs Mu = 6069 tt-Ibs S = S = Smax 7-- 21.4 in 21.2 in 21.2 in -OK Ru = 2087 pif #5 hairpins net #5@ 15''o/c #5 hairpins net #5@ 18"o/c Anchorage at Bottom of the Wall cOVn = 6700p1f (Mtn = 5580p1f Ru = 2870 pif Nominal Shear friction capacity of the footing to wall Dowel 9486 pif Rebar Dowel Size = 5 Dowel Area = 0.31 sq-in Dowel strength fy= 60 ksi Dowel Spacing = 12 inches Coefficient of friction = 0.6 smooth surface ��LW 6TW?- PLAN VIEW CLOSURE TO WALL DOWELS @ EA PLANK. ELEVATION VIEW x I LID TO CLOSURE DOWELS @ EA PLANK, II SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project Beliwether INTERIOR WALL HEADER GEOMETRY AND LOADS ANALYSIS Header Overburden & Uniform Loads sheet 15 date prj. no. S-19-068 Lid weight Soil Desity Soil Cover depth over lid Plank design clear span left Plank design clear span right Design Uniform Live Load 90 psf 125 pcf Load Factors 3 ft LL 1.6 15 ft DL 1.2 15 ft 150 psf Lid tributary width to header 15 ft Uniform service load to header Uniform factored load to header Truck Wheel Loads to Header 9225 plf 11970 plf Truck type outrigger Axle Load 45000 Ibs Wheel Spacing 1 ft Cover depth 3.0 ft Axle assumed centered over & perpendicular to header distribution width 6.50 ft opening width 6.00 ft distribution length 8.00 ft uniform load @ top of plank 865 psf wheel load to header from left span 3000 plf wheel load to header from right span 3000 plf Total wheel load to header 6000 plf Factored wheel load to header 9600 plf Design Loads & Forces in Header length ea side of hdr 4.00 ft Service Factored 15.2 klf 21.6 klf Critical section for shear is at 0.9 feet from the face of the support Design Vu = Design Mu = 45 k 97 k-ft SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project Bellwether INTERIOR WALL HEADER DESIGN Header Data sheet ILP date g -lc3lc prj. no. S-19-068 Header width Header span Header depth In/d ratio Min shear steel ( Area / spacing ) ratio Max spacing of shear steel Min horiz steel ( Area / spacing ) ratio Max spacing of horzontal steel Review shear capacity of header 8 inches 5.00 ft 30 inches 2.22 Concrete Strength 4000 psi d = 27.00 inches Deep Beam limit In/d < 5.0 0.012 6 inches 0.02 10 inches Min Rebar spacing # 3 @ 9.17 # 4 @ 16.67 # 4 @ 10.00 # 5 @ 15.50 Reinforcing yield strength 60 ksi Shear reinforcing area 0.20 sq in spacing 6 in Reinf shear capacity (i)Vs 43 k Total Shear Capacity 66 k Max cPVn @ In/d < 2 93 k Max clAin @ 2 < In/d < 5 10565 k Review flexural capacity of header Horz reinf area 0.31 sq in Horz reinf spacing 12 in Conc shear capacity OW 23 k Factored shear Vu 45 k min As based on 200 bwd/fy min As based on eq 10-3 0.72 sq inches 0.68 sq inches As reqd based on bending model 0.86 sq inches As reqd based on tie - strut model assume Vu is focused @ the center of the header then Tu = As reqd = 50.33 k 0.93 sq inches SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project Bellwether Design Data : Wall Foundation Loads Analysis sheet 13 date prj. no. S-19-068 Soil Desity Soil Cover over the lid Plank weight Uniform Live Load Truck Rating Wall Height 125 pcf 3 ft 90 psf Per. wall Cell Width 15 ft Int. wall Cell Width left 15 ft Int. wall Cell Width right 15 ft 150 psf HS25-44 Front Axle Load 10000 Ibs Rear Axle #1 Load 40000 Ibs 8.08 ft Rear Axle #2 Load 40000 Ibs Total vehicle wt 90000 Ibs Truck Wheel Load Distribution to Perimeter Wall Foundation Truck Perpendicular to the perimeter wall w/ rear axle #2 directly over wall & distance to axle #1 = 14ft total truck load to wall = 42667 Ibs distribution width = 30.16 ft Load @ base of wall = 1415 plf Truck Parallel to the perimeter wall w/ one wheel over wall & 2nd wheel on plank (incl axle 1 &2 only) total truck load to wall = 64000 Ibs calc distribution width = 38.16 ft Load @ base of wall = 1677 plf I'd Pal> 13rt:Oio Truck Wheel Load Distribution to Interior Wall Foundation Truck Perpendicular to the int. wall w/ rear axle #2 centered over the wall & dist between axles = 14ft total truck load to wall = 42667 Ibs distribution width = 30.16 ft Load @ base of wall = 1415 plf Truck Perpendicular to the interior wall w/ rear axle #2 directly over wall & distance to axle #1 = 14ft total truck load to wall = 42667 Ibs left plank Load @ base of wall = 1415 plf total truck load to wall = 42667 Ibs right plank Load © base of wall = 1415 plf distribution width = 30.16 ft Truck Parallel to the interior wall w/ one wheel over wall & 2nd wheel on plank (incl axle 1&2 only) total truck load to wall = total truck load to wall = distribution width = 64000 Ibs left plank Load @ base of wall = 1677 plf 64000 Ibs right plank Load @ base of wall = 1677 pif 38.16 ft Truck Parallel to the interior wall w/ the truck centered over the wall (incl axle 1 &2 only) total truck load to wall = 64000 Ibs distribution width = 38.16 ft Load base of wall = 1677 pif Uniform Live Load distribution to Wall Footings Perimeter Wall Interior Wall 1125 plf 2250 plf ,o'te•-irpind9 17&, 16N1 SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project Bellwether Design Data : Wall Foundation Design sheet date prj. no. S-19-068 Allowable Bearing Pressure Rebar strength fy = Concrete strength = 4000 psf 60 ksi 3000 psi Soil Desity 125 pcf Soil Cover over the lid 3 ft Perimeter Wall Footing Design Per. wall CeII Width Int. wall Cell Width left Int. wall CeII Width right Plank weight Wall Height Wall Thickness 15 ft 15 ft 15 ft 90 psf 8.08 ft 8 inches Design live load 1677 plf Soil Cover dead load Plank dead load Wall dead load 3063 plf 735 plf 808 pif total dead load 4606 plf Total live + dead Load, 6283 pif Required Ftg Width 1.57 ft Selected Ftg Width Qu = 4105 psf As regd = Asmin = 1.33 x As regd = 0.02 sq-in/ft 0.35 sq-in/ft 0.03 sq-in/ft Interior Wall Footing Design L.F 1.6 1.2 1.2 1.2 Wu 2683.2 plf 3675 pif 882 pif 969.6 plf 5526.6 plf 2 ft Selected Ftg Thickness Mu Vu = phi \in= 912 ft-Ibs 2737 pif 9498 plf 8210 plf at face of wall at face of wall at face of wall 12 in Design live load Soil Cover dead load Plank dead load Wall dead load 2250 pif 5625 plf 1350 pif 808 plf total dead load Total live + dead Load Required Ftg Width Selected Ftg Width Qu = 4082 psf 7783 pif 10033 plf As regd = 0.09 sq-in/ft Asmin = 0.35 sq-in/ft 1.33 x As regd = 0.11 sq-in/ft 2.51 ft 3.17 ft Mu = Vu = phi VII= L.F 1.6 1.2 1.2 1.2 Wu 3600 plf 6750 plf 1620 plf 969.6 plf 9339.6 pif 12939.6 plf Selected Ftg Thickness 3197 ft-Ibs 5109 pif 9498 plf at face of wall at face of wall at face of wall 12 in e tructures A DMelon of Kaenik Engineering PC Protect Sheet 11 ' Date °-C- 11 Job No 11 411 �2a ft :11 %ite tructuros A Dlvlelon of Koenik Engineering PC Protect /w 2 Sheet Date Job No 4906 I LAA 14. c1 9. SITE STRUCTURES 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Project Bellwether sheet: (I Reinforcing at Top of Wall Below Grated Opening Design Data date: prj. no. S-19-068 Top of Footing to Inside Top of Vault (H1) Top of Footing to Finished Grade (H2) Soil Pressure EFW Controlling Lateral Surcharge Grating Span SURCHARGE; WS2 SOIL PRESSURE Calculated Design Forces 8.08 ft 11 ft 45 pcf 73 psf 10 ft curb height curb horz reinf bar area curb horz reinf spacing depth to center of reinf curb thickness INSIDE TOP OP VAULT 1.92 ft 0.31 12 in o/c 4 in 8 in Ws1 = 495 Ws2 = 73 Fen curb = 116.2 plf avg Fbot of curb = 159.4 pif Fbot of wall = 568 pif Mwall uniform = 6571 ft-Ibs Mwall triangle = 3956 ft-lbs Load Factor 1.6 Wu = 2085 Wall Reinforcing Mu horz curb = 9MrIburb = Mbase of wall = R = Mu horz wall = 1453 ft-Ibs 4883 ft-Ibs 10527 ft-Ibs 1303 pif 26058 ft-Ibs curb self -supported Wall Thickness Clear Cover Vert Rebar Size Rebar Area conc strength fc Closure Reinf As in Closure 4)Mn = 8 in 2 in 5 0.31 sq-in 4000 psi (3) - # 6 1.33 sq-in 48016 ft-Ibs , Addl Horz Reinf # of Addl Bars As @ Top of Wall 1.33 q-in depth to reinf (d) 5.00 in comp block (a) 1.95 d - a/2 4.03 in Mu = 26058 ft-Ibs SITE STRUCTURES Project Bellwether sheet: 020 10511 19th Ave SE, Suite C Everett, WA, (425)-357-9600 Beam Design Below Grated Opening Design Data date: - prj. no. S-19-068 Height of Curb: Curb Thickness: Soil Density: Beam Width: Beam Span: Truck Rear Axle Load: Calculated Design Forces Soil Weight = Curb Weight Self Weight = Wheel Load = 125 pif 150 pif 156 pif 25000 Ib Load Factor: DL 1.2 LL 1.6 Wu = 518 plf Pu = 40000 Ib Design for Flexure 2 ft 6 in 125 pcf 12 in 5 ft 50 ,k Reinf Size 6 # of Top & Bot Reinf 3 Area of Steel 1.33 sq-in Depth to Reinf (d) 10.13 in Comp Block (a) 2.60 in d - a/2 8.83 in 0Mn = 52636 ft-Ibs Design for Shear Mu = 51617 ft-lbs Tie Reinf Size 4 Area of Steel 0.20 Depth to Reinf (d) 10.50 Max Spacing 5.25 in Reinf Spacing 5 in IrDVc = 5866 Ibs (0Vs = 42057 Ibs 0Vc +4)Vs = 47923 Ibs Vu = 41294 Ibs S►tbar al s-1°►-0118 LW PRODUCTS COMPANY, INC. 8333 219th Street S.E., Building A Woodinville, WA 98072 SPECIFICATIONS For: Type "HS","HD", "HD-SBS" and "HID" LW ACCESS HATCH Fabricated aluminum access hatches to support live load of H-20 wheel load with a maximum deflection of 1/150th of the span. H-20 doors are designed for off street locations where not subjected to high density traffic and conform to AASHTO M306. Door leaf shall be aluminum diamond plate 5086 ASTM B209 with support beams on the underneath side of 6061-T6 ASTM B209 that will transfer the load bearing to the 'A" extruded aluminum channel frame of 6061 T-6 ASTM B209 that has a 1" anchor flange around the perimeter, and is equipped to receive a 3/8" round EPDM gasket for a weather tight seal and has the capability to achieve an air tight or odor tight seal. A 1 %" aluminum drain coupling is integrated into the frame work for an appropriate water drainage. Compression springs are enclosed in telescopic stainless steel tubes which makes the opening of the hatch cover easy, smooth and controlled through both opening and closing. When the door leaf is opened in a vertical position it will automatically lock into place with a hold open arm that has a release handle. The hold open arm has a stainless steel pin attached so that it maybe inserted through the hold open arm to act as a secondary safety insurance. The door is equipped with heavy stainless steel hinges. The door latches shut with a stainless steel snap lock. A removable turn handle is provided for access into the hatch cover and a threaded cover plug for when it is not in use. Hardware used on all hatch covers is stainless steel, 300 series. Factory finish is a mill finish. Manufacturer shall guarantee against defects in material or workmanship for a period of five years. A Thermion finish may be applied with the coefficient of friction complying with ASTM C 1028 89 as Access Hatch Model "HS" and "HD" (H-20 Rating) _ LW PRODUCTS COMPANY, INC. "ACCESS DOORS BUILT TO LAST' 8333 —219th Street SE, Building A Woodinville, Washington 98072 Phone (425) 483-0300 Fax (425)485-2058 Aluminum Type "HS" Access Doors (Single Leaf Door) Both type "HS" and type "HD" features reinforcing channel framework that transfers the the load from the 1/4" aluminum diamond plate Drib coda door leaf to the door frame, and our stainless steel spring lift makes the opening of our heal doors easy. The locking support arm holds the doors open automatically. We use 3/8" EPDM to achieve a weather -tight seal. All hardware used on our hatches is stainless steel, 300 series, except the 1 %2" aluminum drain coupling and the removable handle used for access into the hatch. All LW HATCHES are provided with a self - latching stainless steel slam lock and with a recessed padlock hasp so they can be locked with a padlock. All type "HS" and type "HD', doors are designed for use in off street locations where not subjected to high density traffic.. However, special provisions may be made to the hatch to allow use in higher density traffic'. location when requested. May be cast in an 8" slab. Type "HS" (Single -leaf door) STANDARD SIZE Type "HD" to (Double -leaf door) STANDARD SIZE Lodi %r'ag A,na CyEaea Eolopat* Wim,Din Type "HD" (Double -Leaf Door A Part # A B C D E F G HS-1 24"x24" 24"x30" 24"x36" 24"x42" 24"x48" 24"x60" 24"x72" HS-2 30"x30" 30"x36" 30"x42" 30"x48" 30"x60" 30"x72" 30"x84" HS-3 36"x36" 36"x42" 36"x48" 36"x60" 36"x72" 36"x84" 36"x96" HS-4 42"x42" 42"x48" 42"x60" 42"x72" 42"x84" 42"x96" 42"x108" HS-5 48"x48" 48"x60" 48"x84" 48"x96" 48"x108" 48"x72" Part # A B C D E F HD-1 36"x48" 36"x60" 36"x72" 36"x84" 36"x96" 36"x108" HD-2 42"x42" 42"x48" 42"x60" 42"x72" 42"x84" 42"x96" HD-3 48"x48" 48"x60" 48"x72" 48"x84" 48"x96" 48"x 108" HD-4 60"x60" 60"x72" 60"x84" 60"x96" " 60"x120" HD-5 72"x72" 725<84" 72"x96" 72"x108" 72"x120" 72"x132" Hinges Plan view of 72"x 120" hatch frame all aluminum construction 6061-T6 128 4 Drain Couplings 120 V° Bearing shelf 7 425 483-0300 Pad lock recess L,W.Products Co Inc t a End sections wit bearing shelf i Drain Gutter Reihhnrc dConcrete A Bearing Shelf 'tnsidedimceion Groove for neoprene seal End sections w r lout bearing shelf L.W.Products 425 483-0300 ERM!T COORD COPY PLAN REVIEW/ROUTING SLIP PERMIT NUMBER: D19-0317 DATE: 11/27/2019 PROJECT NAME: THE CONFLUENCE APTS - VAULT SITE ADDRESS: 3481 S 152ND ST Original Plan Submittal X Response to Correction Letter # Revision # before Permit Issued Revision # after Permit Issued DEPARTMENTS: Building Division Public Works n n Fire Prevention Structural n WI AI? Ili\ 61 Planning Division Permit Coordinator III PRELIMINARY REVIEW: Not Applicable n (no approval/review required) DATE: 11/28/19 Structural Review Required REVIEWER'S INITIALS: DATE: El APPROVALS OR CORRECTIONS: DUE DATE: 12/26/2019 Approved Corrections Required (corrections entered in Reviews) Approved with Conditions Denied (ie: Zoning Issues LI Notation: REVIEWER'S INITIALS: DATE: Permit Center Use Only CORRECTION LETTER MAILED: Departments issued corrections: Bldg 0 Fire 0 Ping 0 PW 1:1 Staff Initials: 12/18/2013 SITE STRUCTURES A Division of Kosnik Engineering, PC October 11, 2021 City of Tukwilla Building Department 6300 Soutcenter Blvd, Suite 100 NE Tukwilla, WA 98188-2544 RECE1 _ CITY OF T U.,+ ?EMIT OEN Ref: The Confluence Affordable Apartments AKA Bellwether TOD Apai thnents Storm Water Detention Vault Permit No. D19-0317 Site Structures Project Number: S-19-068 As Structural Engineer of Record, I have reviewed the following items related to the construction of the detention vault. • Concrete Technology Corporation's hollow core plank calculations and placement drawings. • CT Sales Inc reinforcing bar shop drawings. • Miles Sand & Gravel concrete mix design. • Otto Rosenau & Associates field inspection reports and concrete materials reports. • LW Products Company access hatch submittals. • Grating Pacific LLC sump grating submittal. • Site Drain Strip 9000 prefabricated soil drain product submittals. Based on this information, it is my opinion that the detention vault on this project was constructed in conformance with the intent of the structural drawings dated 10-25-2019. Please feel free to call if I can be of any further assistance. Sincerely, banieL fCvsyti�c Daniel Kosnik, SE President Cc: Dan Miller, Rafn Company 10505 19th Ave. S.E., Suite B; Everett, WA 98208 ♦ (425) 257-9600 (phone) ♦ dan@kosnik.com City of Tukwila Department of Community Development 10/4/2021 JAKE DRAKE 25 CENTRAL WAY STE 400 KIRKLAND, WA 98033 RE: Permit No. D19-0317 THE CONFLUENCE APTS - VAULT 3481 S 152ND ST Dear Permit Holder: Allan Ekberg, Mayor Nora Gierloff, Director In reviewing our current records, the above noted permit has not received a final inspection by the City of Tukwila Building Division. Per the International Building Code, International Mechanical Code, Uniform Plumbing Code and/or the National Electric Code, every permit issued by the Building Division under the provisions of these codes shall expire by limitation and become null and void if the building or work authorized by such permit has not begun within 180 days from the issuance date of such permit, or if the building or work authorized by such permit is suspended or abandoned at any time after the work has begun for a period of 180 days. Your permit will expire on 11/10/2021. Based on the above, you are hereby advised to: 1) Login to the City of Tukwila's Online Portal https://tukw-egov.aspgov.com/BP/index.html to schedule for the next or final inspection. Each inspection creates a new 180 day period, provided the inspection shows progress. -Or- 2) Submit a written request for permit extension to the Permit Center at least seven(7) days before it is due to expire. Address your extension request to the Building Official and state your reason(s) for the need to extend your permit. The Building Code does allow the Building Official to approve one extension of up to 180 days. If it is determined that your extension request is granted, you will be notified by mail. In the event you do not call for an inspection and/or receive an extension prior to 11/10/2021, your permit wili become null and void and any further work on the project will require a new permit and associated fees. Thank you for your cooperation in this matter. Sincerely, Elisa Villegas Permit Technician File No: D19-0317 6300 Southcenter Boulevard Suite #100 • Tukwila, Washington 98188 • Phone 206-431-3670 • Fax 206-431-3665 City of Tukwila Department of Community Development 6300 Southcenter Boulevard, Suite #100 Tukwila, Washington 98188 Phone: 206-431-3670 Web site; http://www.TukwilaWA.gov REVISION SUBMITTAL Revision submittals must be submitted in person at the Permit Center. Revisions will not be accepted through the mail, fax, etc. Date: 11-21-2019 Plan Check/Permit Number: D 19-0317 ❑ Response to Incomplete Letter # • Response to Correction Letter # 1 ❑ Revision # after Permit is Issued ❑ Revision requested by a City Building Inspector or Plans Examiner ❑ Deferred Submittal # Project Name: The Confluence Apts - Vault Project Address: 3481 S 152 St Contact Person: Chris Miller RECEIVED or/ OF TUKWILI NOV 2 2 2019 PERMIT CENTER Phone Number: 425-250-7249 Summary of Revision: 1. TP-01 and TP-02 tree protection has been updated. Tree protection detail has been added to TD-01. 2. Note added to sheet 3 (TP-01) regarding Urban Environmentalist inspection. 3. Sheet SH200 has been updated (see full shoring response letter from Michael Nouwens) Sheet Number(s): TP-01, TP-02, TD-01, and SH200 "Cloud" or highlight all areas of revision including date of revision Received at the City of Tukwila Permit Center by: 0. Entered in TRAKiT on // I:\Projects\ 18. 183\Jurisdiction\City of Tukwila\Forms\Revision Submittal PW 19.0120 (Vault permit).doc Revised: August 2015 0� �J� U� � � � �J�� Dl ����� � �v�u v-�^ �� *^�' �� ^v v� .. "~�n � Structural Consultants Mr. Bill Rambo, Permit Technician City ofTukwila Department ofCommunity Development G30OSouthcenterBoulevard, Suite 1OO Tukwila, VVA98188 RE The Confluence Apartments — Vault —3482S252n«Street Permit Application Number Q19-0317 Response toCity ufTukwila Correction Letter #2 November 21, 2019 Dear Mr. Rambo: The following is our response to the City of Tukwila correction letter #1 dated November 15, 2019: 3. The tree protection fencing isnow shown onSHJOD. Please let usknow ifyou require any additional information. Sincerely, Michael NouwensStructural Consultants Michael LNnuwens, SE LEED11 Green Associate Enc. SH200 RECEIVED CITY OF TNKWILA NOV� � ���� "wwv � � ��nm 1? 11 Wo 0 !0(3 P.c\Box yxz N soMowos'vvavoozoN pzo6 5468446Ec Reid iddleton CIVIL ENGINEERING STRUCTURAL ENGINEERING SURVEYING PLANNING November 14, 2019 File No. 262019.005/01402 Mr. Jerry Hight, Building Official City of Tukwila, Department of Community Development 6300 Southcenter Boulevard, Suite 100 Tukwila, WA 98188 RECEIVED NOV 1 5 2019 Community Development Subject: Building Peiinit Plan Review — Final Submittal The Confluence Apartments — Vault and Temporary Shoring (D19-0317) Dear Mr. Hight: We reviewed the proposed project for compliance with the structural provisions of the 2015 International Building Code (IBC) as amended and adopted by the state of Washington and the City of Tukwila. The peiiiiit applicant has responded successfully to our comments. The comments below do not require a response from the permit applicant. Drawing Revisions New structural drawing sets were submitted in response to our plan review. These sets are enclosed and should replace any previous sets submitted with the original permit submittal. The new drawing sets are dated October 25, 2019. Special Inspections, Submittals, and Tests Geotechnical special inspections: Special inspections and tests by the geotechnical engineer should be provided as recommended in the geotechnical report by PanGEO, Inc., dated September 12, 2019. The following is a summary: 1. Verify materials below shallow foundations are adequate to achieve the design bearing capacity (IBC Section 1705.6). 2. Installation and testing of soldier pile wall systems (IBC sections 110.1 and 1705.1.1). 3. Construction of modular block retaining walls (e.g., Keystone, Lock+Load, ecology block, crib walls) (IBC Sections 110.1 and 1705.1.1). Structural special inspections: Special inspections by qualified special inspectors should be provided. Please reference the special inspections indicated in the drawings. The special inspections provided should include but not be limited to the following summary: 1. Placement of temporary shoring piles (IBC Section 1705.7). 2. Placement of concrete (IBC Section 1705.3). 3. Placement of reinforcing steel (IBC Section 1705.3). ALASKA I CALIFORNIA I WASHINGTON 728 134th Street SW, Suite 200, Everett, WA 98204 1 425 741-3800 I www.reidmiddleton.com 1-1 \N-1 Mr. Jerry Hight, Building Official City of Tukwila, Department of Community Development November 14, 2019 File No. 262019.005/014R02 Page 2 4. Curing and formwork placement (IBC Section 1705.3). 5. Erection of precast concrete (IBC Section 1705.3). Structural deferred submittals: Portions of the structural design have been deferred by the structural engineer for submittal to City of Tukwila until after issuance of the initial building permit. The applicant has been informed that the City of Tukwila may require the issuance of additional permits. The following is a summary: 1. Concrete mix designs. 2. Design drawings for precast, prestressed, hollow -core concrete floor slabs (e.g., Concrete Technology, see also ICC-ES ESR-2152). 3. Lightweight hatch assembly drawings. 4. Design drawings for Ultrablock shoring. Corrections and comments made during the review process do not relieve the permit applicant or the designers from compliance with code requirements, conditions of approval, and permit requirements; nor are the designers relieved of responsibility for a complete design in accordance with the laws of the state of Washington. This review is for general compliance with the International Building Code as it relates to the project. Enclosed are the drawings, geotechnical report, structural calculations, and other submittal documentation. If you have any questions or need additional clarification, please contact us. Sincerely, Reid Middleton, Inc. Jnifet D. J6hnson, P.E. Corbin M. Hammer, P.E., S.E. Project Engineer Enclosures cc: Jake Drake, Blueline (by e-mail) Dan Kosnik, Site Structures (by e-mail) Siew Tan, PanGEO Incorporated (by e-mail) Jerry Hight, City of Tukwila (by e-mail) Al Johannessen, City of Tukwila (by e-mail) Bill Rambo, City of Tukwila (by e-mail) Rachelle Ripley, City of Tukwila (by e-mail) ehw\\26Se\Plan Review\Tukwila\19\TKI9014R02.docx\sss Principal Engineer Reid iddleton r City of Tukw Department of Comm November 15, 2019 JAKE DRAKE 25 CENTRAL WAY STE 400 KIRKLAND, WA 98033 unity Development RE: Correction Letter # 1 DEVELOPMENT Permit Application Number D19-0317 THE CONFLUENCE APTS - VAULT - 3481 S 152ND ST Dear JAKE DRAKE, Allan Ekberg, Mayor Jack Pace, Director This letter is to inform you of corrections that must be addressed before your development permit can be approved. All correction requests from each department must be addressed at the same time and reflected on your drawings. I have enclosed comments from the following departments: PLANNING DEPARTMENT: Lynn Miranda at 206-433-7162 if you have questions regarding these comments. • 1. Sheet 3 or 7. Tree protection fencing is located incorretly for trees on west property line and single tree on east property line. See TMC 18.54.070 for compliance with standards. See #3 - physical barriers, such as a 6' chain link fence or plywood or other approved equivalent, shall be placed around each individual tree or grouping at the Critical Root Zone. See also #6 - regarding installation of a waterproof sign. 2. Add note to sheet 3 - prior to any on -site construction, tree protection measures must be inspected by the City's Urban Environmentalist, Andrea Cummins, who can be reached at Andrea.Cumrnins®Tukwilawa.gov. 3. Sheet SH200. Show correct location of tree protection fencing at CRZ. Please address the comments above in an itemized format with applicable revised plans, specifications, and/or other documentation. The City requires that two (2) sets of revised plan pages, specifications and/or other documentation be resubmitted with the appropriate revision block. In order to better expedite your resubmittal, a 'Revision Submittal Sheetmust accompany every resubmittal. I have enclosed one for your convenience. Corrections/revisions must be made in person and will not be accepted through the mail or by a messenger service. Sincerely, bLUc7"?.61, Bill Rambo Permit Technician File No. D19-0317 6300 Southcenter Boulevard Suite #100 • Tukwila Washington 98188 • Phone 206-431-3670 • Fax 206-431-3665 Reid iddleton CIVIL ENGINEERING STRUCTURAL ENGINEERING SURVEYING PLANNING October 22, 2019 File No. 262019.005/01401 Mr. Jerry Hight, Building Official City of Tukwila, Department of Community Development 6300 Southcenter Boulevard, Suite 100 Tukwila, WA 98188 OCT 2 8 2019 Community Development Subject: Building Permit Plan Review — First Submittal The Confluence Apartments — Vault and Temporary Shoring (D19-0317) Dear Mr. Hight: We reviewed the proposed project for compliance with the structural provisions of the 2015 International Building Code (IBC) as amended and adopted by the state of Washington and the City of Tukwila. The design team should address the comments below. The permit applicant should provide responses to the review comments in an itemized letter. The structural engineers should resubmit the following documents: a. Three sets of full-sized revised and new structural sheets for insertion into the original structural drawing sets. Complete structural drawing sets may be submitted in place of individual new and revised sheets. b. Three complete full-sized sets of updated structural drawings. c. Three copies of supplemental structural calculations. The geotechnical engineer should submit information as requested in the comments. The applicant should resubmit documentation directly to Reid Middleton, Inc. Geotechnical 1. Geotechnical special inspections and tests should be performed for this project. See IBC Sections 1704.2.3, 1704.3.1, 1705.6, and 1705.7. A table of the required inspections is provided in the Structural General Notes on Sheet SH100 (for the temporary shoring) in the section titled Inspection and on S1 (for the vault structure) in the section titled Special Inspection Plan. The following is a summary of the required geotechnical special inspections and tests based on a review of the structural drawings and the geotechnical report. ALASKA I CALIFORNIA I WASHINGTON 728 134th Street SW, Suite 200, Everett, WA 98204 425 741-3800 www.reidmiddleton.com 0 Mr. Jerry Hight, Building Official City of Tukwila, Department of Community Development October 22, 2019 File No. 262019.005/01401 Page 2 a. Verify materials below shallow foundations are adequate to achieve the design bearing capacity. See IBC 1705.6. b. Installation and testing of soldier pile wall systems (IBC Sections 110.1 and 1705.1.1). c. Construction of modular block retaining walls (e.g., Keystone, Lock+Load, ecology block, crib walls) (IBC Sections 110.1 and 1705.1.1). 2. Geotechnical observations should be performed as recommended in the geotechnical report by PanGEO, Inc., dated August 7, 2017, on page 14. We recommend providing a list of geotechnical observations in the section of the Structural General Notes on Sheet SH100 (for the temporary shoring) and on S1 (for the vault structure) titled Geotechnical Criteria. See IBC Section 107.2.1. The following is a summary based on a review of the geotechnical report: a. Installation of temporary shoring system at excavations (IBC Section 1803.5.10). b. Installation of permanent subsurface drainage system (IBC Section 1805.4) c. Placement and compaction of structural backfill (IBC Section 1803.4). Structural General Structural special inspections and tests should be performed for this project. See IBC Sections 1704.2.3, 1704.3.1, and 1705. A table of the required inspections is provided in the Structural General Notes on Sheet SH100 (for the temporary shoring) in the section titled Inspection and on S1 (for the vault structure) in the section titled Special Inspection Plan. The following is a summary of the required structural special inspections and tests based on a review of the structural drawings. a. Placement of temporary shoring piles (IBC Section 1705.7). b. Placement of concrete (IBC Section 1705.3). c. Placement of reinforcing steel (IBC Section 1705.3). d. Curing and formwork placement (IBC Section 1705.3). e. Erection of precast concrete (IBC Section 1705.3). 2. The Concrete Notes on Sheet S1 specify concrete strengths of 3,000 psi and 4,000 psi. The project appears to have concrete elements exposed to freezing and thawing cycles, which qualifies as Class F2 concrete per ACI 318-14 Table 19.3.1.1. Per ACI 318-14 Table 19.3.2.1, the minimum concrete strength for Class F2 concrete is 4,500 psi. The minimum concrete strength on Sheet S1 should be revised. See IBC Section 1901.2. Reid iddleton /Th Mr. Jerry Hight, Building Official City of Tukwila, Department of Community Development October 22, 2019 File No. 262019.005/01401 Page 3 Structural deferred submittals. Portions of the structural design have been deferred by the structural engineer for submittal to the city of Tukwila until after issuance of the initial building permit. The applicant should recognize that the City of Tukwila may require the issuance of additional permits. See IBC Section 107.3.4.1. The following should be included in the structural notes on Sheet S 1: a. Concrete mix designs. b. Design drawings for precast, prestressed, hollow -core concrete floor slabs (e.g., Concrete Technology, see also ICC-ES ESR-2152). c. Lightweight hatch assembly drawings. d. Design drawings for Ultrablock shoring. Temporary Shoring 4. Structural calculations for the design of the wood lagging for the soldier pile wall do not appear to be included in the submitted calculations package. Documentation substantiating the design of lagging as shown on Sheet SH100 should be provided. See IBC Section 1603.1. 5. The Ultra -Block wall is noted on Sheet SH200 as designed by others. This is not noted in the general notes as a deferred submittal. Clarification should be provided for the design status of the Ultra -Block walls noted on the plan. See IBC Section 107.3.4.1. Vault 6. The northwest corner of the vault plan on Sheet S2 notes a detail call -out of Detail 1/S2. This detail does not exist in the set of plans provided. The detail should be verified. See IBC Section 1603.1. 7. Detail 2/S3 is specified at the central bearing wall location on Sheet S3. This detail appears to conflict with the detail specified on Sheet S2 (Detail 2/S4), along the same wall line. The details should be verified and revised to match the intended condition. See IBC Section 1603.1. 8. On Sheet S3, Detail A/S5 is specified at the hatch location of the vault. However, Sheet S5 does not appear to be included, in the submitted drawing package. The location of the detail should be verified. Additional information is required. See IBC Section 1603.1 Reid iddleton Mr. Jerry Hight, Building Official City of Tukwila, Department ofCommunity Development October 22, 2019 File No. 262019.005/01401 Page 4 Corrections and comments made during the review process do not relieve the peunit applicant or the designers from compliance with code requirements, conditions of approval, and permit requirements; nor are the designers relieved of responsibility for a complete design in accordance with the laws of the state of Washington. This review is for general compliance with the International Building Code as it relates to the project. If you have any questions or need additional clarification, please contact us. Sincerely, Reid Middleton, Inc. fe roject En neer cc: Jake Drake, Blueline (by e-mail) Dan Kosnik, Site Structures (by e-mail) Siew Tan, PanGEO Incorporated (by e-mail) Jerry Hight, City of Tukwila (by e-mail) Al Johannessen, City of Tukwila (by e-mail) Bill Rambo, City of Tukwila (by e-mail) Kandace Nicols, City of Tukwila (by e-mail) Rachelle Ripley, City of Tukwila (by e-mail) ehw\O:\Plan Review\Tukwila\19\TK19014R01.docx\sss nson, P.E. Corbin M. Hammer, P.E., S.E. Principal Engineer Reid iddleton City of Tukwila Allan Ekberg, Mayor Department of Community Development - Jack Pace, Director October 8, 2019 Dave Swanson Reid Middleton 728 - 134th Street SW, Suite 200 Everett, WA 98204 RE: Supplemental Structural Review Development Permit D19-0317 The Confluence Apts - Vault — 3481 S 152 St Dear Mr. Swanson, Please review the enclosed set of plans and documents for structural compliance with the 2015 International Building Code. As always, once all items have been reviewed and deemed correct, please provide two approved sets of approved plans and calculations with original approval stamps back to the Permit Center, attention Building Official. If you should have any questions, please feel free contact us in the Permit Center at (206) 431-3670. Sincerely, Bill Rambo Permit Technician end File: D19-0317 Tukwila City Hall • 6200 Southcenter Boulevard • Tukwila, WA 98188 • 206-433-1800 • Website: TukwilaWA.gov Pir COOK) COPY' PLAN REVIEW/ROUTING SLIP PERMIT NUMBER: D19-0317 DATE: 09/30/19 PROJECT NAME: THE CONFLUENCE APTS - VAULT SITE ADDRESS: 3481 S 152 ST _ X Original Plan Submittal Revision # before Permit Issued Response to Correction Letter # Revision # after Permit Issued DEPARTMENTS: Artii /0 /0 Building Division Vkil\A NO 11 Public Works it° VI Fire Prevention iztfi 11-6-11 Structural UY1 Cr' I° mil° Planning Division in Permit Coordinator PRELIMINARY REVIEW: Not Applicable (no approval/review required) REVIEWER'S INITIALS: DATE: 10/01/19 Structural Review Required DATE: LI APPROVALS OR CORRECTIONS: DUE DATE: 10/29/19 Approved Corrections Required Approved with Conditions 1-1 Denied (corrections entered in Reviews) (ie: Zoning Issues) Notation: REVIEWER'S N TIALS: DATE: Permit Center Use Only CORRECTION LETTER MAILED: .41 Departments issued corrections: Bldg 0 Fire E] Ping PW D Staff Initials: bp( 12/1812013 i\ `_/ MICHAEL NOUWENS Structural Consultants Jerry Hight Building Official I City of Tukwila 6300 Southcenter Blvd, Suite 100 Tukwila, WA 98188 Dear Jerry: RE: Bellwether Affordable Apartments — shoring permit submittal Signature on Plans September 26, 2019 This letter is to confirm that on September 26, 2019, I, Michael L Nouwens PE SE, electronically affixed my signature to the Bellwether Affordable Apartments shoring drawings and shoring calculations that are dated September 30, 2019. Sincerely, Michael Nouwens Structural Consultants Michael L. Nouwens, PE, SE LEED® Green Associate 9-26-2019 bi'i 0311 RECEIVED COTE O u J (WIL, SEP 3 0 2019 PERROT d CLEF ER P. 0. B 0 X 9 21 ■ E D M O N D S, WA 9 8 o z o • p: 2 o 6 5 4 6 8 4 4 6 • e: michael@nouwens-structural.com ^ y` av«oswomsLdtemo Seattle, mm98,m �}�}/' vo"xo �oa z*z*z3o - Fax. (206)2421527 mpt.wv. Li 3-3 1-1 L CERTIFICATE OF SEWER AVAILABILITY / NON AVAILABILITY Resi�n�m�$sV,on ��mmpr����/om\ow p Certificate cfSewer Availability OR r Certificate of Sewer Non -Availability Part A:(To BeCompleted By Applicant) Purpose of Certificate: 0 Building Permit [] Preliminary Plat orPUD [] Short Division [] Rezone [] Other Proposed Use: [] [umnnerda| [] Residential Single Family Z Resideotialkxu|d'Fami|y [] Other AppUcant'sName ' Bellwether Tukwila, LuPhone , P,opertyAdd,ess s*o1s15zwosrTukwila, WA. yo1xx Tax Lot Number oo*3mm1nu Legal Description (Attach Map and legal Description ifNeoessary); Ao*wsHOME rns3noADD m1zopr Part 8:(To beCompleted by Sewer Agency) 1O � OR 00 a�ASewer Sem)cpwiUbeprovided byside sewer connection only toanexisting size sewer feet from the site and the sewer system has the capacity to serve the proposed use. b. Sewer service will require animprovement tothe sewer system of. F&,^a of .1 [] (l) Tob feet of sewer trunk orlateral toreach the site; and/or AmArL° Pk*'/^a /s w^l**' (�) Thecons�ructionofaco||eczion�y��emonrheteand/o,fk4"' CACS. ".O=P44", [] d Q_ e&mme_C_fx, -at( m ��^,+ O (s) Other(describe) 1111k ^f z. Must becompleted ifl. babove ischecked a. The sewer system improvement is in conformance with a County approved sewer comprehensive r plan, OR r b. The sewer system improvement will require a sewer comprehensive amendment. 3.4ecti�wirh\n,hecorpo,ate|imsoftheDistrictorhasbeeng,arted8oundary (_ a. The proposed po� Review Board approval for extension ofservice outside the District. OR r a. Annexation or8R8approval will benecessary *oprovide service. 4Service � a. b.sasemeno c � I hereby from the By re� ' Pcrn,iz$ 1.65 pm District Connection Charges due prior tnconnection: Gpc: $ 3, 2.2 5pC: $ -rg_6 / Unit: $ Tuta| P&r °°,r (Subject to Change on Januaryt) ��J $� ~7H =�4 * ^�v/�/� p�* N. /� ~ Eithe,a King County/METRO Capacity Charge, SWSSD or Midway Sewer District Con necti(eff, Y Charge may be due upon connection to sewers. � []Requi,e� [��aybexeqvi,ed w^x-v or - ��� ��"^ Other l �����[ " �^ certify that the above sewer agency information is true. This certification shall be valid for one year date ofsignature. n,/e ��__x Date5-4,("k ww 2019 7F � CEwnou.vu � /N 11� ATTACHMENTTO VALLEY VIEW SEWER DISTRICT CERTIFICATE OF SEWER AVAILABILITYMON-AVAILABILITY The following terms and conditions apply tuthe attached Valley View Sewer District ("District") Certificate of Sewer Availability/Non Availability ("Certificate") l. This certificate is valid only for the real property referenced herein ("Property") which is in the District's service area, for the sole purpose of submission to the King County Department of Development and Environmental Services, King County Department ofPublic Health, City nfSeattle, City vfTukwila, City of Burien and/or City of SeaTac. This certificate is between the District and the applicant o4fly and no third person or party shall have any rights hereunder whether by agency, third -party beneficiary principles or otherwise, I This Certificate creates oocontractual relationship between the District and the applicant and its successors and assigns and does not constitute and may not be relied upon as the District's guarantee that sewer service will be available at the time the applicant may apply to the District for such service. I As of the date of the District's signature onthis Certificate, the District represents that sewer service issmUaWeto the Property through sewer systems that exist orthat may beextended bythe applicant. The District makes no other representations, express or implied, including without limitation that the applicant will be able to obtain the necessary permits, approvals and authorizations from King County, City of Seattle, City of Tukwila, City of Burien, City of Seatac or any other governmental agency before the applicant can utilize the sewer service which isthe subject ofthis Certificate. 4. If the District orthe applicant must extend the District's sewer system to provide sewer .service tothe Property, the District ovapplicant may herequired »oobtain from the appropriate governmental agency the necessary permits, approvals and authorizations. In addition, the governmental agency may establish requirements that must be satisfied as a condition of granting any such permits, approvals or authorizations, which may make impractical or impossible the provision of sewer services to the Property. s. Application for and possible provision ofsewer service u`the Property shall besubject uoand conditioned upon availability of sewer service to the Property at the time of such applicaticn, and compliance with federal, state, local and District laws, ordinances, policies, and/or regulations In effect at the time of such /acknowledgothat /have received the Certificate of Sewer *vailabilitylNon -Availability and this attachment, and fully understand the terms and conditions herein. Applicant's signature t.tiy Wt t Ufl YV tits Depa 'nt of Community Development 6300 bL.=tcenter Boulevard, Suite # 100 Tukwila, Washington 98188 Phone: 206-431-3670 Web site: http://www.TukwilaWA.gov AVAILABILITY PERMIT NO.: Part A: To be completed by applicant Site address (attach map and legal description showing hydrant location and size of main): 3481 S 152nd St. Tukwla, WA 98188, 3601 S 152nd St. Tukwila, WA. 98188, 3703 S 152nd St. Tukwila, WA. 98188 Owner Information Agent/Contact Person Name: Bellwhether Tukwila LLLP ,Name: Chris Miller - Blueline Address: 1651 Bellevue Ave. Seattle, WA 98122 Address: 25 Central Way Kirkland, WA. 98033 Phone: (206) 623-0506 Phone: 425-216-4051 This certificate is for the purposes of: 0 Residential Building Permit ® Commercial/Industrial Building Permit ❑ Preliminary Plat ❑ Rezone ❑ Short Subdivision ❑ Other Estimated number of service connections and water meter size(s): 1 - 3" domestic water, 1-2" irrigation, 1-6" fire sprinkler supply Vehicular distance from nearest hydrant to the closest point of structure is 255 ft. Area is served by (Water Utility District): Water District 125 3/13/2019 Date ilECEt'EL CCTY OF TUKWILA Part B: To be completed by water utility district Tel KOLA%KI 4 G 1. The proposed project is within 2. L_l No improvements required. (City ty3 0 2019 PERMIT d CENTER 3. The improvements required to upgrade the water system to bring it into compliance with the utilities' comprehensive plan or to meet the minimum flow requirements of the project before connection and to meet the State cross connection control requirements: (Use separate sheet dmore room is needed) 4. Based upon the improvements listed above, water car be provided and will be available at the site with a flow of .3A2.50 gpm ar20nsi residual for a duration of 2 hours at a velocity of IRA, , , fps as documented by the attached calculations. 5. Water availability: CAcceptable service can be provided to this project Acceptable service cannot be provided to this project unless the improvements in Item B3 are met. System is not capable of providing service to this project. q 0 3 I hereby certify that the above information is true and correct. i arrE9,r1 crittcr- .025 L .4 D3.-29 -19 By ate sxetEs (-2.1-20) Agency/Phone 2t.!2 - e51 t Knc CoLinty ItYatel' nistri,rt No , 12 The foloyvii-Ig r*,onnir:erLi aPPiy ;ertifc,ate Availavo (Certificate") 1, This Certificate of Water Availability is valid only for the real property referenced herein for the sole purpose of submission to the City of Tukwila ("City"). This Certificate is issued at the request of the City and is not assignable or transferable to any other party. Further, no third person or party shall have any rights hereunder whether by agency or as a third party beneficiary or otherwise. 2. The District makes no representations, expressed or implied, the applicant will be able to obtain the necessary permits, approvals and authorization from the City or any other applicable land use jurisdiction or governmental agency necessary before applicant can utilize the utility service which is the subject of this Certificate. 3. As of the date of the issuance of this Certificate, the District has water available to provide utility service to the real property which is the subject of this Certificate, and the utility systems exist or may be extended by the applicant to provide service to such property. However, the issuance of this Certificate creates no contractual relationship between the District and the applicant or the City, and the issuance of this Certificate may not be relied upon and does not constitute the District's guarantee that water utility service will be -. available to the real property at the time the applicant may apply to the I District for such service. 4. Application for and the possible provision of District utility service to the real property which is the subject of this Certificate shall be subject to and conditioned upon the availability of water service to the real property at the time of such application, as well as all application for utility service, including conservation, water restrictions, and other policies and regulation then in effect. Applicant's Signature District Representative Date /13/2019 Date 3/2949_ BLUELINE To: King County Water District 125 Re: Water availability request Request for service of a residential multi -family development. Address: 3481 $ 152nd St. Tukwila, WA. 98188 Parcel: 0043000108 Description: ADAMS HOME TRS 3RD ADD N 120 FT Plat Block: 2 Plat Lot: 7 Address: 3601 5 152nd St. Tukwila, WA. 98188 Parcel: 0043000112 Description: ADAMS HOME TRS 3RD ADD LESS N 120 FT Plat Block: 2 Plat Lot: 7 Address: 3703 S 152nd St. Tukwila, WA. 98188 Parcel: 0043000116 Description: ADAMS HOME TRS 3RD ADD W 63 FT OF LOT 8 Plat Block: 2 Plat Lot: 8 'south 154th street p South 154th Street 0 r 4714 ,�xra� J714 1714 "37 b ••L 7147 I' 4714 .4714 O ,1714`7'714. 3.714, 11 'r� i'3i:4�, 0714 W3714 tR Y;77 " r ,l f3714 '374 - J700 4, 09 14 03/14/2019 101 va•ITT5 44 5w 0.mx s.pctl ar Parcel 0043000108 3700 3,i7OO Scu h 154th Street THEBIUELINEGROUP,COM MA 425 2'5 405' 15 Central Nay, Suile 400 I Kirsoano, NA 90033 Parcel 0043000116 Parcel 0043000112 0 Some online services are currently uriavailable. See a list of service outages. (httos://lni.wa.aov/agency/system-status) 4 4.°4 Whshinqton SI,tq Dt.rArto,at la Labor & Industries (https://lni.wa.govl ontrac ors RAFN COMPANY Owner or tradesperson Principals RHODE, SHAWN S, PRESIDENT BEAULIEU, HEATHER R, VICE PRESIDENT BOTTLES, M KIM, VICE PRESIDENT AMBREY, THOMAS J, CHIEF EXECUTIVE OFFICER DANIEL M HENDRICKSON, AGENT RAFN, JACK M, PRESIDENT (End: 05/02/2012) RAFN, MARILYN, SECRETARY (End: 05/02/2012) AMBREY, TOM JR, TREASURER (End: 05/02/2012) Doing business as RAFN COMPANY WA UBI No. 600 275 503 1721 132ND AVE NE BELLEVUE, WA 98005-2250 425-702-6600 KING County Business type Corporation Governing persons JACK M RAFN TOM AMBREY; KIM BOTTLES; License Verify the contractor's active registration / license / certification (depending on trade) and any past violations. Construction Contractor Active Meets current requirements. License specialties GENERAL License no. RAFNC**061J7 Effective — expiration 04/27/1994— 04/20/2020 Bond TRAVELERS CAS & SURETY CO $12,000.00 Bond account no. 081S103535374BCM Received by L&I Effective date 04/18/2002 04/20/2002 Expiration date Until Canceled Insurance HARTFORD ACCIDENT & INDEMNITY $1,000,000.00 Policy no. u\* LEGAL DESCRIPTION PARCEL A: LOT 7, BLOCK Z THIRD ADD177ON 70 ADAMS HOME TRAC73t RECORDED IN VOLUME 15 OF PLAM PAGE 17, 1N KING COUNTY, WASH/NGTON. PARCEL B. THE WEST 63 FEET OF LOT A BLOCK Z THIRD ADDITION 70 ADAMS HOME TRACT$ RECORDED IN VOLUME 15 OF FLA7. PAGE 17, RECORDS OF KING COUNTY, WASHINGTON BASIS OF BEARING N0050716 BETWEEN THE FOUND MONUMENTS AT THE SOUTHWEST CORNER OF SEC 22-23-4 AND THE WEST QUARTER CORNER OF SEC 22-23-4 DATUM VERTICAL DATUM: NAVD 86 HORIZONTAL DATUM: MAD 83191 BENCH MARK GLASS DERIVED RESTRICTIONS THIS SITE IS SUBJECT 70 AND EASEMENT RECORDED OC70SER 19 1959 AS DISCLOSED BY INSTRUMENT RECORDED UNDER RECORDING NUMBER 509255Z (SHOWN HEREON) SURVEY NOTES 1. ALL 777LE 1NFORMA77ON SHOWN ON THIS MAP HAS BEEN EXTRACTED FROM FIRST AMERICAN 777LE INSURANCE COMPANY FILE NUMBER NCS-854401-WAI, DATED JUN£ 20, 2017. IN PREPARING THIS MAP, CORE DESIGN, INC. HAS CONDUCTED NO INDEPENDENT 777LE SEARCH NOR IS CORE DESIGN, INC. AWARE OF ANY 777LE ISSUES AFFECTING THE SURVEYED PROPERTY OTHER THAN THOSE SHOWN DN THE MAP AND DISCLOSED BY THE REFERENCED FILE NUMBER. CORE DESIGN, INC. HAS RELIED WHOLLY ON FIRST AMERICAN 777LE INSURANCE COMPANYS REPRESENTA77ONS OF THE 7711ES COND17ION TO PREPARE THIS SURVEY AND THEREFORE CORE DESIGN, INC. QUAUFIES THE MAPS ACCURACY AND COMPLETENESS TO THAT EXTENT. 2. THIS SURVEY REPRESENTS WSIBLE PHYSICAL IMPROVEMENT CONDITIONS EXISTING ON AUGUST 1, 2017. ALL SURVEY CONTROL INDICATED AS 'FOUND" WAS RECOVERED FOR THIS PROJECT IN AUGUST, 2017. J. PROPERTY AREA = 56,314t SQUARE FEET (1.2928t ACRES). 4. ALL DISTANCES ARE IN FEET. 5. THIS IS A FIELD TRAVERSE SURVEY. A SOKKlA FIVE SECOND COMBINED ELECTRONIC TOTAL STA77ON WAS USED TO MEASURE THE ANGULAR AND DISTANCE RELA71ONWPS BETWEEN THE CONTROLLING MONUMENTA770M AS SHOWN. CLOSURE RA770S OF THE 7RAVERSE MET OR EXCEEDED THOSE SPECIFIED IN WAC 332-130-090. ALL MEASURING INSTRUMENTS AND EQUIPMENT ARE MAINTAINED IN ADJUSTMENT ACCORDING TO MANUFACTURERS SPECIFICATIONS 6. UTILITIES OTHER THAN THOSE SHOWN MAY EXIST ON THIS SITE ONLY THOSE UTIUTTES WITH EVIDENCE OF THEIR INSTALLATION VISIBLE AT GROUND SURFACE ARE SHOWN HEREON. UNDERGROUND U77UTY LOCA77ONS SHOWN ARE APPROXIMATE ONLY. UNDERGROUND COIVNEC77ONS ARE SHOWN AS STRAIGHT UNES BETWEEN SURFACE U77UTY LOCATIONS BUT MAY CONTAIN BENDS OR CURVES NOT SHOWN. SOME UNDERGROUND LOCA77ONS SHOWN HEREON MAY HAVE BEEN TAKEN FROM PUBLIC RECORDS CORE DESIGN ASSUMES NO LIABILITY FOR THE ACCURACY OF PUBLIC RECORDS 1 02019 THE BLUEUIVE GROUP NE i SW 114, BELLWETHER FIL Copy Pofintt No _ Plan review appr 5 . pmIS5i0nS. Aoproval REVISIONS Aotauthor¢e ne c "sruc roc , ordinance RecalD No e':a e snap , a0e to the scope Of WOnt witnOUI p, -� —nroval or the Tukwila Bmldutq Division. -Date _12i_21 �Cf NOTE: Revlsltins will require a new plan _ submittal and may include additional plan review. .,x. -------------- ¢:::�:s:;::::.... '-. .........................':< z [.... 185.98 --- -a 21FOUND M - t :.. CONCRETEONUMENTIN112 t292.74 NTH 2 DISCW/PUNCH 0.40 :�:::::�..�. II��:..��,,}}��rtrt �+► .::-. r.::::::::.:.:.:.:.:.::..:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:.:..:<.:......,....:..�... _:_,..�;..,::.:.:.:-,.,..,:.:-�:..-.._.�r:._�::�:::::,: DOWN !N CASE tt t 1 i I 0 ifVA 0 OP EG P R PROPr75EJ7 APARTMENT �rV IE E3 ty l r 1 u ti W I '7 :j I N �. 0 a�ILi jl 2 Qb 01 6 to � G h tt Nyt N I OClJ 1i'd� �R {\f R 73_ ____ N 884 85.92' __ _ Pf10'OOk Tg 026fl A, I I I I i IqIOiy�I�I 90 9235900 4T ( L00 A-CPPR I �Ok30 pr�P�� p 0� I A3tyOp'1P�St a 005 I �¢�OO 0 2 00 I 3Pyy G P 0 OOJ Nth li TP -41-_I I� GQOR�P i9 t0 I - 1q 1 t 27122 E 160TH ST FOUND MONUMENT !N /28 27 N 88 3758" W 2636.05' REVIEWED E— CONCRNJ BRASS DISC WITH This plan was reyinved for general conformance 1r ti the following 0 amended by the jurisdiction: - 0.71' DOWN IN CASE CM Structural proyisiqus of the International Building Code. C3 Non -Structural provisions of the International Building Code ❑ Others: The project applicant is responsible for conformance with all applicable codes• conditions of approval, and penultrequirements subject to the requirements and interpretations of the goveming authority. This review does not relieve the Architect and Hngincen of Record of the responsibility fora complete designina ecordance- wah fhe laws of the governing jurisdiction and the State of Washington. Jurisdiction BY 1i_Laar i f Date — L/ l REID MIDDIFTON INC. Code R wuv Conx pant I � I / I CAL TED CENTER SE ON CORNER I SE22 S I 1 � I � I I I I I I VICINITY MAP NOT TO SCALE PROJECT TEAM OWNER CIVIL ENGINEER BELLWETHER TVKWlIA LLLP BLUEUNE 1651 BELLME AVE 5 2 CENTRAL WAY SUITE 400 SEAT7LF- WA 0122 KIRKLAND, WA 96033 {206) 588-482T (425) 250-7249 CONTACT: EMMA GEYER CONTACT.• CHRISTOPHER H. MILLER, PE ARCHITECT LANDSCAPE ARCH JOHNSON BRAUND, INC BLUEUNE 15200 52ND AVE $, SU17E 300 25 CENTRAL WAY, SUITE 400 SEATILE, WA 98188 KIRKLAND, WA 98033 {206) 766-8300 (425) 250-7249 CONTACT.. DTANA KEYS CONTACT: CHRIS PE]ERSEN, PLA SURVEYOR CORE DES16N 14711 NE 29TH PL. 1 101 85A 98007 (EUW7877 CONTACT: GLENN R. SPRAGUE, PLS SITE DATA SITE ADDRESS J481 S 152ND ST, TUKWiLA, WA 9818E TOTAL S17F AREA. 56.314 SF NEW PARCEL 1 AREA: 56,314 SF REPLACED IMPERVOUS: 14,495 SF LOT IMPERVIOUS COVERAGE: 79.4X V I SEPARATE PERMIT RES?UIR ch FOR: MEWED j-►j Mechanical (Ca>f�f n d Electrical U iumbing NOV 1 4 2019 Gas Piping City of T"UKwiia SHEET INDEX BUILDINGDMSION REID MIDDLETON, INC. 1 CV-0 1 COVER SHEET 2 EC-01 EXISTING CONDITIONS 3 TP-O 1 TESC & GRADING PLAN - PHASE 1 4 TP-02 TESC & GRADING PLAN - PH VI EDFOR 5 TO-01 TESC DETAILS CODE COMPLIANCE 6 VT-0 i VAULT PLAN APPROVED 7 VT-02 VAULT PLAN DEC 06 2019 FDE�1���'A li OCT 0 00 2019 f - 2 to Zut � , oDS. ot4 of REID MIDDLETON, ON, INC. r SHL7RING PLANS SH 100 TEMPORARY SHORING NOT SH200 TEMPORARY SHORING PLAN VAULT PLANS 51 52 53 S4 STRUCTURAL SHORING NOTES & DETAILS VAULT FOUNDATION PLAN & DETAILS VAULT LID PLAN & DETAILS WALL SECTIONS & DETIALS CITY OF T LIIK ILA GRADING QUANTITIES 30 2019 CUT. 8,950 CY FILL: 300 CY <CUT> 8,650 CY PERMIT CENTER QUANTITIES FOR PERMITTING ARE APPROXIMATE AND SHALL NOT BE USED FOR CONTRACTUAL PURPOSE UNDERGROUND UTILITY NOTE UNDERGROUND U77U71ES ARE SHOWN IN 774E APPROXIMATE LOCATION. THERE IS NO GUARANTEE THAT ALL UTILITY LINES ARE SHOWN, OR THAT THE LOCA77ON, SIZE AND MATERIAL IS ACCURATE. THE CONTRACTOR SHALL UNCOVER ALL INDICATED PIPING WHERE CROSSING INTERFERENCES, OR CONNECTIONS OCCUR PRIOR TO TRENCHING OR EXCAVATION FOR ANY PIPE OR STRUCTURES, TO DETERMINE ACTUAL LOCATIONS, SIZE AND MATERIAL THE CONTRACTOR SHALL MAKE THE APPROPRIATE PROVISION FOR PR07E'C77ON OF SAID FACILITIES. THE CONTRACTOR SHALL N077FY ONE CALL AT 8-1-1 (WASHINGTON811.170M) AND ARRANGE FOR FIELD LOCATION OF EXISTING FACIL177ES BEFORE CONSTRUCTION. N 25 CENTRAL WAY, SUITE 400, KIRKMD, WA W33 R 425.216.4051 P:426.216.4052 W WW.THESLUELINEGROUP.COM SCALE. AS NOTED PROJECT MANAGER: CHRISTOPHER H. MILLER, P£ PROJECT ENGINEER: JON L KOEPFGEN, PE DESIGNER: NADIA KROUMOVA ISSUE DATE: 9/26/2019 y z 0 W tY m Q 4 Z Z E.I �d T rx N W 'Q In 1.. w W noJ E3 WLU M � 0 V �0AER y 2\c�� QWASH Zj zA, zA b w "0 9500 F El I ST<;RE'�G�2 ssiONAL 91119 JOB NUMBER: I8-183 SHEET NAME: is CV-0 1 5HT 1 OF 7 NE 114, SW 114, SEC 22, TWP 23 N, RGE 4 E, W.M. h-----------.— --. --- ——- ------ --- — I—R------ I - „�; --- 2',��\�.L\��.L��L���L\a�t\�.L � y I `•��Q_,r-- �� _- II �I ".2H0-,- —dHO-- , d'49FTtT--'`tea"— o,v `_X=�-F;r__6�r•>af-� .-'fix EX C8 8087 TYPE I -- s ."' \ RIM 32725 I 0. . _ I. o , `` I ( �-C\ a \ _ _ , rM 78%7D" --r 12"CONCIE325.90O �1:F'.J'�,M1 r'\'. h 1 ^_ , xI 12" D! lE 325.87 (E) I �, r.. :.cn . , �. ' r- 'r _- - - r �HE \o J \ .R \",�.� \./ , I 1 yO F-F�CRRR� I DEC-,�7" , ICCTV L '. -I _...:� ,.-. , o • I I I �. I �\ �� \ / '--� ��, i\\RR\�\�\�\�\�\ \y I �'`•, , \ t/ \\\ M-12� `10" / I I- 4- 1 Fx 1 €x eLDc- }:.''-.•.. ',.a I CARPORT\`�EXBLDG Imo` / \�'3705 I \ 1\ EXBLDG . : (j+ I �DEMOUS}1E15J f� '\ ` 3703 .,- I '= '- CL_F \ ' CLF . ' I '\ 3707 I I'}.::' Ila1= \ I ?.-4'... -. T. I D£MOUSH�D \ „(DEMOLISHED) EX I `, n t I FCARPORT x I '\ (DEMOLISHED) N0 PARKING f I ::".N .t.L' I 3 �'° II I ri \ �-'� '^- �+ L OF HERE lCN L }'. :. N.. I a PG-4 �\ k _ i , �'• ( \ ;Y I , 1 I/F-26" \\\` . 1 i( .�., .. • - . )i I I (TEST PIT) L� — — — — — — —t , �` i r \ — — L --( —�` I \\L�w 326,28EE.:i..I\+ I . F-34" ( I M i HY 6/6/G- L�i: 12"CONC ISO CLF X �`i—X-1 3'CLF X_—®(TEST PIT) DEC-6/8/6" ,I "r{.: '.:-'" .:i.N ....'.... , zz 'G=----,= G-_— =. ^=.G'_ —,—•- z�--�.— T— `="G= — L- 1 — L — ..• r _ G _ '._ PG-2 1 I. I — — — r. Tll — ro.' r:: ?1 0 %P ) e f. . c� rn' o NTURY I,! LINK A-17" 30' PRIVATE — M-6/8/6" _ t I INGRESS/EGRESS {. EASEMENT REC. EX CB 8086 TYPE `�I I ``� \ NO. 5092557 J ? I':::'': i": t RIM 332.46 -f -- I ---- \ ' (TO BE VACATED) -- 12"CONC 1E 330.71 (£) \ 1 t l DEC-12 I - PG-3 ', `\`\ (TEST PIT) A-12" , \ ! c , Ja SHED I , C-34 1!DEMOLIShIED)�I � 'NO PARKING o, Ii - , `� �\�\-\-- I`� _--' U I I I 1 r 1 ON WALKWAY 1 tA-." . II, I I 1� f'.:. ! tn.. ( I' I DEC-rl2" SIGN '=�.-,, / / \��I "( , .\lyy= I I� / EX BLDG U I .,_� �}.��:'..'• ��� �:•�.-.'.�,I ( F � 3481 \� I,( I� - (DEMOLISHED) I Ex SSMH 8t89 a y RIM 334.33 t2'"OJ lE 323.53 +'.-..: f:•:-. I. I \ \ i PG-1 1 8"DI 1E 323.43E) j iii.l.'..,-. I Ii`I v t3i) I '+ TEST PlT ZD - NO CC V 0 SDRx-3PF TE i"' --- CA _ ^ I I \ i 0 (TEST PIT) 12"CONClE�•.%�'�'.'� q��'' '6:�.v�.�':- h'- F O I � \\\� `\\\Y 'i j 1 i ---dHO�-.'. ' --F----------------}-- I , 1 CM19 THE allELINE GROUP II II l II ( I I I I I I I I REVIEWED FOR CODE COMPLIANCE APPROVED DEC 0 6 2019 City of Tukwila ILDIE DIVISION A MPERMIT CENTER m�$Qe UNDERGROUND UTILITY NOTE UNDERGROUND U711177ES ARE SHOWN IN THE APPROXIMATE LOCA770N. THERE IS NO GUARAN7EE THAT ALL U77LITY LINES ARE SHOWN, OR THAT THE LOCA77ON, SIZE AND MA7ERIAL IS ACCURATE 7HE CON7RACTOR SHALL UNCOVER ALL INDICATED PIPING WHERE CROSSING, INTERFERENCES, OR CONNEC7701VS OCCUR PRIOR TO TRENCHING OR EXCAVA770N FOR ANY PIPE OR S7RUC711RES, TO DE7ERMINE ACTUAL LOCATIONS, SIZE AND MA7ERIAL 7HE CONTRACTOR SHALL MAKE THE APPROPRIATE PROVISION FOR PROTEC77ON OF SAID FACIU77ES THE CON7RACTOR SHALL N077FY ONE CALL AT 8-1-1 (WASHINGTON811.COM) AND ARRANGE FOR FIELD LOCA770N OF EXISTING FACIL177ES BEFORE CONS7RUC770N. 25 CENTRAL WAY, SUITE 400, KIRKINJD, WA 96033 P: 425.216A051 F: 425.216.4052 W W W.THESLUELINEGROUP.COM SCALE.• AS N07ED PROJECT MANAGER: CHNSTOPHER H. MILLER, PE PROJECT ENGINEER. JON L KOEPFAEN, PE DESIGNER: NADIA KROIIMOVA ISSUE DATE.• 1112012019 N Z Q j W a ga S m� C ❑ 2 2 W rX Q 4 Q. z p QIn U1 ra La W ®LL Q v �pHER y WAsyV1f U O 70 z ro -PO 9500GISTC 4 FSSIONALRENG\� G121%1 JOB NUMBER: 18-183 SHEET NAME: E"C-0 1 SHT 2 OF 7 NE 114, SW 114, SEC 22, TWP 23 N, RGE 4 E, W.M. r..} - - - - - - - - - - - - - - - - - ` - - - - - ` - - - ` { I 4�j+co j. l o j p�p2 "CONC SD Cp3J rA ( I \ 1r 12 ..... .... . 'hf0 PARKING E OF HERE SIGN ( int } �6 .` f� _ 1` -_I•o } zo ,,-- �. ...,ZEMPA21TARY 1,000 SF MIN AT EL 326.0 I I I II .Il • ' . 1 �. I I. �� BOTTOM EL 322.5 EX CB 80B7 TYPE t TOP OFBERM 327.O ' C LL�yL\��L��L R1M 327.25 72" CONC LE 325.90 (W L r� 1 y I f ) _ • ` 12" DI LE 325.87 (E) i ' a .. , :. '� ' , '. 1� � 6 CLF %r- - - - � - _ - �- - - - � 6" CLF SS- - - .p 5 ,la �1� / III \ CTv �'.�.� f (I I �_ i ' i INTER PTORSWALEW)TH. '' " '' '` �r �I TR ROCK CHECK DAMS �� " 0f fE I { i r� n'. (" ( CONy�7RUQTI N ,� ii e' (np) 26.28 ....-a. ... 326 _. .... %." i FENCI \ - . ,. ., rr LI.{ \ \ ( \ II-t f (. '•' . ''. i CONS7RUC ON ttNCEp:~ 320 P 31 TOOE 3f t.2 4 DAYLIGHT ]EMP FORCE .. vi i +o ( TYp �� ' P 4" HDPE �. tit 3/8 III MAIN IN DITCH Ifr PROVIDE �. �. I •�- `�.tr3RCEMAlN ''�� t " r r 3ffi 314". �I a - - \316 ROCK CU}FALC PAD r J --- I t�• �����d' ,I ��- I�.- III { TEMP�SUMP PUMP W17NtN TEMfi ftp 24 DIA`HDPE PERFORATED RI - I _ II PP RIM EL 326.0 ,----- _ r LOT 7/8 LINE PER ADAM NCM6 TF,AgTS PLAT- F \\\ COA�STRUCTIDN fENCE�• 36' WIDE �. •.........LI,.. .i `� �. ._-��_ __---_ ` `�i �' MM�M ATE - _20WOO'PROPOSE/ \ F G GATE TYP CON 7RUCTION ENTRANCE : • _ j. } '. q g., `, CLEARING UM175 CENTURY �',,;y�?'•.!m I ( _ CULVERT t s; 7YP 1RY f w LINK ( _ t 1 "7 ` EX CB 8D86 TYPES I �� • , , " TOP 315.7 �5 RIM 332.46 • 1 "+'I I o ( ,a �? /r �`u' t1 TOE 3t1.2 12" CONCIE 330.71((E) i h hri Fh H ULTRA BLO SHORING WALL 14 , l N SEE SHEET TD-01 FOR DETAIL I>rl TON { I't '•t. . n. tl� l ( I I°a,.` / VAULT AO ` 'a I i t UPON COMPLETION -DE ON �' VAULT CONSTIRUC ON REMOVE BEL 07TOM82 6 (' f• f (.� ' t TEMPORARY SEDIMENT TRAP AND 00 r L FOOTING 2 4 $ ROUTE RUNOFF TO DETENTION VAULT. Et 311.24 1p 'NO PARKING �. (' . !.;, i o ( ? P r i VpA.3 ys pP ON WALKWAY I I;. ..• •• �'.I t UUUIII SIGN I:.. j 111 I I E� 1 p�' a p°� { I Wi !' t Pip 4 q0 P t• PITA a I q . OR ARBORIST TO BE �, i zo zo ONSITE DURXNC CON9 UCTjON EX SSMH 87B .' . I . I . ACTINTY WITHIN DRIPUNES OF RIM 334.33 '{ o I I I TREES TC REMAIN 70 ENSURE '• 4 �.� I fi�l 1 I I t. TREE SURVWAL t SPLDXERPiLE SNORING.WALL t ,� 12" DI IE 323.5{3 W) t r ' : r t 8"Df tE 323.4 E _ ( SEE SHEET ?D-Ol �, TOP 3l .2 4.5 - �'a'.'.''.•..N.,'.'. (I r` TOE31f.2 52 _ CE CONS UC ON t `� X NO CCTV L• I'' _.• "..I( h. I I q l FENC TOP321.0 5a TOE315.7 3�' CONC 1£ 3355 TOP 324.5 2B ' I' ur• I I o I t I '� V t r t t ` t r t + TOE 31 # II - # .�30 �,'. `• I .. �. 1 r 74" t �4 TOP 25 M_ _7 M-7 t j r } �• t _ i 6�it "r r + i �7 n X 3" T rf ..III ..♦ r� "j .� , t\\ _ i� /'� rrr rt` % t Ir ,� rrr t�i` i _ � ` rr i\t \ `/r ti\\ � �r TOE 31i.7 R8/art �I ...... ..... NPIPL BOX "---' --- CAUTfON GAS PIPELINE EX CB 8119 TYPE 1 q o POSSIBLE CO RIM 335.68 ..:•.-:`.}'..:.., '`.u;\ W/METER - 12" CONC LE34.41,(E)._• CATCH BASINtN T 4pry �p� 5 5 }. Q � ra r' q• y•� �h 9 P�Ef T3k QI_ p� G � pip` ti 4i.fl�FtP I..: Pp pppU to ;, EX SSMH 81157 I ' RIM 336.36 o i o 12" Ol fE 325�85 (E) I I I t2" PVC !E 3 5.85 (S) !, 12" DI fE 32 � 75 (W) (i � I , I ' I SS IT �4 -_ .__ T _._ -_ -_ __ __ - _ _ _ __ I-dHO-i- idHOI - -OHP-� �OHF� - - - - -- - - I - REVIEWED FOR CODE COMPLIANCE APPROVED DEC 0 6 2019 City of Tukwila BUILDING DIVISION LEGEND TESC FEATURES JTLTER FENCE JS RIPRAP PAD CONSTRUCTION FENCE JC) ROCK CHECK DAM -► ••• INTERCEPTOR SWALE �...�.�.c iNTERCEPTOR CULVERT ® TEMPORARY RISER TEMPORARY STORM PIPE .$ PIPE FLOW CLEARED AREA RECEIVED LIMITS OF CLEARING CITY OF TUKWILA INTERIM CATCH BASIN NOV 2 2 2019 PROTECTION (INSERT) CONSTRUCTION ENTRANCE PERMIT CENTER 12" CONC SO 0 PARKING T % F HERE SIGN EX C8 f8O87, T R/M_327.25 12- CONC 1E 325,90 (K) 2- DI JE 325.87 (E) 6'CLF A ti0 DISCHARGE POINT FOR ARAINING CRI77CAL ,OF DE 7ON VA T ACTING - ZONE SEDIMENT POND. CONTRACTOR TO (T ENSURE DISCHARGE -DOES NOT --------- EXCEED 25 NTU DRIP LINE (Typ) "DI 1E 628 FORCE DAYLIGHT IN DITCH It PRO WDE M.'I% ROCK OUIFALL fPAD OWK FOREM CENTURY --------- — LINK CULVERT EX CB 8086 TIP 1 RIM 332.46 12' CONC IE JJO. 711 (E) % IX 'OCK NO PARKING 0 TRA LL SHOT SEE SHEET 70-01 ON WALKWA SIGN W 0 EX SSUH 818b RIM 334.33 12' DI IE 32' (W) 6 Of 11 12J. � (E) ko CCTV `.o OR E 16" cow lrl*; J33. 66'. -7 GAS EX CB 119 TYPE) PIPELINE' F CON ��GL Hux POSSIRL W1 METER RIM 335.68 12" CONC IE .34.41-' CATCH eAqfm INSERT A. ( � ! I I I I I a_ T a. . EX SSMH 8167 0 T RIM 336. 5 I, 0 I ' 12" DI IE 325185 (r) 12" PVC 12" DI 1E 32 �Wr ss— _dH0— OHP--OHf'-- hni pry o 9_'W9n1QMFRIIJFT1NFGROUP Mrffim ", ? 0 07, '� W P bk PIQP¢p NE 114, SW 114, SEC 22, TWA 23 N, RGE 4 E, W.M. — — — — — — — — — — — — — — — — --- CRITICAL ROOT ZONE y II 6'CLF I— G --- 7414'4ss_' CATCH BASIN UD TEMPORARY GRADE AND SEDIMENT INSER INSTALLED LOT PER EDAM HOME TRACTS PLAT -- - - - - - - - - - - - - - - - - - - T_ DEMN770N VAULT 70 BE UTM S TRANCE PAD IZ LA 5EDIULnI POND UNI_ V1 97%6AnON ACHIEVED. CONTRACTOR TO U77UZE RA(AL PUMP STATION OR UTILIZE ADDITIONAL SUMPCES5ARY PUMPS To DRAIN VAULT AS NE BL111-61N13 PAD ELEV. 32s`B3 PROJECT ARBORIST TO BE IRUC77ON Ojv.%WjL minvivu CONSTRUCTION FENCING A077WTY WITHIN DRIPLIN SILTFENGE AIN To EN7� _,TREE SUR W JJ 71' "4 0 M-13 - --- --- ---- III P'o C TO U77BID POD VAULT A LIZE lit 77ON ACHIEVED. DO NOT II INSTALL CARTRIDGE AND PROVIDEi. 'MENT PROTEC7701V FOR -SOIL --A y T1 16' WOE � GATE c'm Gt I V776' !/i A �%00 pa il PyR — — I — — - REVIEWED FOR CODE COMPLIANCE APPROVED DEC 06 2019 City of Tukwila BUILDING DIVISION 2.1 SLOPES 2:1 SLOPES � A L �A�� B 2-4-ROCK L s THE DISTANCE SUCH THAT POINTS A AND B ARE OF EQUAL ELEVATION. A CHECK DAM SPACING SECTION A -A NOTES- 1. PROVIDE ROCK CHECK DAMS EVERY 50 FT OR EVERY 2 FT. OF VER77CAL FALL Z ANY SEDIMENT DEPOSITION OF MORE THAN 0.5 FT. IN DEPTH SHALL BE REMOVED SO THAT THE CHANNEL 15 RESTORED TO 17S ORIGINAL DESIGN CAPACITY. 3. THE CHANNEL SHALL BE EXAMINED FOR SIONS OF SCOURING AND EROSION OF THE BED AND BANKS iF SCOURING OR EROSION HAS OCCURRED, AFFECTED AREAS SHALL BE PROTECTED BY RIP —RAP OR AN EROSION CONTROL BLANKET OR NET. 4. SUMP SHOULD BE PROVIDED IMMEDIATELY UPSTREAM OF CHECK DAM FOR OP77MUM EFFEC77VENESS RDCK CHECK DAM NOT TO SCALE PER KCSWDM D.2. f.6.4 t2' TEMPDRARY INTERCEPTOR SWALE NOT TO SCALE PER KCSWDM D.Z1.6.4 0 Ultrablock, 2.5'H x 2.5'W x 5'L Approx. Scale (feet) 0 2.5 5 Modified from North Excavation Sections by Johnson Bmund, August 30, 2019 1 GtJ L BetlwetherAI "dab"a ULTRABLOCK TEMPORARY SHORING Apatimetda .. , a . < ..... 370313705/3001 So 752nd St TUkwlta,WA Project No. imii FgureNo. X SSA FILTER MEDIA FOR DEWATERING �J NE 114, SW 114, SEC 22, TWP 23 N, RGE 4 E, W.M. ,,,— CATCH BASIN ,—GRATE (I I I- ( illll OVERFLOW POROUS BOTTOM -) I NOTE.- THIS DETAIL IS um r MA 77C. ALL 1 I--- INSERT ST HAVE A MIN. —) I 0.5 C.F. OF STORAGE THE MEANS TO DEWA THE STORED SEDIMENT —) FLOW AND BE EAAN SILY MAIN AINED.N ALL INSERTS ARE — SUB,ECT TO APPROVAL I— BY C.O.R. INSPECTORS. Ell alai CATCH BASIN INSERT NOT TO SCALE PER KCSWDM D.2.1.5.3 NOT TO SCALE PER KCSWDM D,2.1.4.1 A TE IRMMAMY SED1MF7J 'r 7-)7dP WIRE BACKING 1S USED NO7E FILTER FABRIC FENCES SHALL BE INSTALLED ALONG CONTOUR WHENEVER POSSIBLE WATERPROOF SIGN: A WEA774ERPROOF SIGN SHALL BE INSTALLED ON THE FENCE OR BARRIER WHICH READS TREE PROTECTION ZONE —THIS FENCE SHALL NOT BE REMOVED OR ENCROACHED UPON. NO SOLE DISTURBANCE PARKING,STORAGE, DUMPING OR BURNING OF MATERIALS 1S ALLOWED WITHIN THE CRI77CAL ROOT ZONE. THE VALUE OF THIS TREE 15 VNSERT VALUE OF TREE AS DETERMINED BY A QUALIFIED TREE PROFESSIONAL HERE). DAMAGE TO THIS TREE DUE 70 CONSTRUCTION AC77WTY IHAT RESULTS IN THE DEATH OR NECESSARY REMOVAL OF THE TREE IS SUSXCT TO THE VIOLATION SECTION OF 7MC Tau Y90. ° CRITICAL ROOT ZONE NO7E: 1. PHYSICAL BARRIERS SUCH AS 6—FOOT CHAIN LINK FENCE OR PLYWOOD OR 07HER APPROVED EQUIVALENT, SHALL BE PLACED AROUND EACH INDIVIDUAL TREE OR GROUPING AT THE CRZ 2. ANY ROOTS WITHIN THE CRZ EXPOSED DURING CONSMUCTION SHALL BE COVERED IMMEDIATELY AND KEPT MOIST NTH APPROPRIATE MATERIALS. TREE PROTECTION DETAIL I TREE PROTECTION DETAIL Z NOT TO SCALE NOT TO SCALE PER KCSWDM D.2.1.4.1 nca lef"zim" n 9 1 A f EROSION PREVENTION AND SEDIMENT CONTROL NOTES A. PLANS FOR ANY ACTIVITY THAT DISTURBS GROUND SHALL INCLUDE AN EROSION PREWEN77ON AND SEDIMENT CONTROL PLAN (ESC) DESIGNED IN ACCORDANCE WITH THE ADOPTED KING COUNTY SURFACE WA IER DESIGN MANUAL THE PLAN SHALL PROVIDE INFORMATION FOR TEMPORARY EROSION PREVENTION AND SEDIMENT CONTROL DURING ALL PHASES OF CONSTRUCTION AND SHALL PROVIDE PERMANENT STABILIZATION FOR DISTURBED AREASDURING CONSIRUCRON,7HE DIRECTOR MAY REQUIRE ADDITIONAL MEASURES AS NEEDED 70 PREVENT EROSION AND RETAIN SEDIMENT. S. THE PLAN SHALL EMPHASIZE EROSION PREVENTION RATHER THAN SEDIMENT CONTROL AND SHALL MINIMIZE THE EXTENT AND DURATION OF SOIL EXPOSUR€.IN ADDITION, THE PLAN SHALL MINIMIZE RUNOFF WELOC177ES AND RETAIN SEDIMENT ON —SITE C. AT A MINIMUM, THE ESC PLAN SHALL SHOW CLEARING UMI MSENSITIV£ AREA BUFFERS`AND SHALL PROVIDE TEMPORARY STABIUZA770N,SEDIMENT RE7ENTIDN, AND PERIMETER PRO7ECR0NJN ADDIRON,SOME PROJECTS WILL REQUIRE STABILIZED TRAFFIC AREAS AND SURFACE WATER CONTROLS` WHICH SHALL BE SHOWN ON THE ESC PLAN. THE PLAN SHALL ALSG PROVIDE A DESCRIPTION OF FINAL STABIUZA770M METHODS D. THE PLAN SHALL PROVIDE THE SEED MIX FOR THE TEMPORARY AND PERMANENT SEEDING. E. THE PLAN SHALL REQUIRE COVER MEASURES AS FOLLOWS: 1. AT ALL 7IMESANY DISTURBED AREAS LEFT UNWORKED FOR MORE THAN 30 DAYS SHALL BE SEEDED. 2. MAY 1 THROUGH SEPTEMBER 30 TEMPORARY COWR MEASURES SHALL BE INSTALLED ON ALL AREAS LEFT UNDISTURBED FOR MORE THAN SEVEN DAYS RECEIVED J. OC70BER 1 THROUGH APRIL 30, MINIMUM WET SEASON REQUIREMENTS., CITY OF TUKWILA o. INSTALL TEMPORARY COVER MEASURES ON ALL AREAS THAT WILL REMAIN UNWORKED FOR MORE THAN TWO DAYS AND ON STOCKPILES AND STEEP CUT AND FILL SLOPES NOV 2 2 2019 b. RETAIN ONSITE A QUANTITY OF COVER MEASURES MATERIALS SUFFICIENT TO COVER ALL DISTURBED AREAS PERMIT CENTER a BY OCTOBER B TEMPORARY SEED AND MULCH ALL AREAS THAT WAL BE UNWORKED DURING THE WET SEASON. d. MULCH ALL SEEDED AREAS UNDERGROUND UTILITY NOTE e. STABILIZE ALL CONSTRUCTION TRAFFIC AREAS UNLESS ALREADY GRAVELED. 4 ®2019 THE BLUELINE GROUP NE 114, SW 114, SEC 22, TWP 23 N, RGE 4 E, W.M. VAULT EXTERIOR SCALD 1-- 10' REVIEWED FOR CODE COMPLIANCE RECEIVED APPROVED CITY OF TUKWILA DEC 06 2019 NOV 2 2 2019 PERMIT CENTER City of Tukwila BUILDING DIVISION F00TING DRAIN NE7TES 1. FOO TING DRAINSPERFORA TED P VC IN 314' OR I —Y2" WASHED ROCK WRAPPEDW1 MIRAR 1401V OR APPRO VED EQUAL AND INSTAA T A SL OPE OF 0.00 2. CLEANOUTS IN SIDEWALKS OR DRIVE AISLES SHALL HAW CAST IRON RING AND COVER SET FLUSH WITH FINAL GRADE j. CLEANOUTS IN SOFT AREAS TO RECEIVE CONCRETE COLLARS 4. BENO� wyE-a ETC. (AS NECESSARY) TO BE DETERMINED By CONTRACTOR- 5. FOOTING DRAINS TO BE LAID FLAT OR WITH POS177W SLOPE TOWARDS COIVNEC77ON TO PROPOSED STORM SYSTEM. 6. CLEANOU75 SHALL BE PROVIDED EVERY 100'OR 135* IN DIREC71ONAL CHANGE VAULT INTERIOR SCAM 10 s 10' i t lefr-ml STANDPIPE NE 114, SW 114, SEC 22, TWP 23 N, RGE 4 E, W.M. PROPOSED ��APQ; I 24 ( I ` ACCESS ) ! EX1577NG (Mj TOP OF L!DI D EL �327.74 I BOTTOM EL 32a70 -- I OF UD ; F_- ! 7. 4EqIMEMR IN PERFF PVC IE3T3J2_ . 312.24 ! J_ S' OPENING INTERIOR- IN I _ I 7' LtVE STORAGE 6" MIN AVERAGE SEDIMENT STORAGE _ TOP OF SEDtMENT I STORAGE 6'MIN FREEBOARD { 312.24 _ _EL3t3.t 113.122=1 I 1 i I 121' a } 6' 6" 4 61MW 1 uAv 2 ti u END PLATE ELBOW DETAIL SCALE NIS I r� g i O W N u N k>i N 2 4i (D2019 7H£ BLUEUNE GROUP Lftl�l WP"s 310 SECTION A A SCALE: 1'= 10' PROPOSED 24 ��N)OLE EXISTING GROUND (�) — ACCESS TOP OF UD EL 327.74 BOTTOM EL 320.7 F UD GRADE (T,fp) �._. 6" MIN ' FREEBOARD WRAP VAI L _— f5' — — 15' - PERIMETER A 4" PERF VG !E 313.1 - OF SEDIMENT S MIN AVERA 7O EL 313.t2 OIMENTSTORAGE SECTION B-B SCALE 1" = 10' ANOACNSCREEN TO CUP CROSS W/6-1"METAL SCREWS-2 PERSTRAP, OR USE STAINLESS PS6 STEEL PIPE CLAMP TACK WELDWIRE MESH 0.25")(0. 5'X16 TO BOTTOM PLATE GAGE STAINLESSLD STEEL WIRE MESH 72 GAGE STAINLESS STEEL 60TTOM PLATE FLOW CONTROL SCREEN SCALE., NIS 340 330 320 1310 4GE AOJUSTABL£i HOOK 0 ( 1�SHEAR GATE SHALL BE., A. CAST IRON BODY AND GATE, OLYMPIC FOY, STD., OR EQUAL B. ALUMINUM, DRAINAGE SPECtAL71ES (SAVANNA, GA) Slit OR EQUAL, 2. GATE SHALL BE 6" DIAMETER UNLESS 07HERK13E SPECIFIED. J. GATE SHALL BE JOINED 70 TEE SEC110N BY SOLTtNG (THROUGH FLANGE), WELDING OR 07HER SECURE MEANS 4. LIFT ROD: AS SPECIFIED BY MANUFAC71IRER WITH HANDLE EXTENDED 70 107HIN ONE FOOT OF COVER AND ADJUSTABLE HOOK LOCK FAS7ENED 70 FRAME OR UPPER HANDHOLD. DETAIL -SHEAR GATE SCALE NIS 34CI 330 310 FLOW CONTROL RISER DETAIL SCALE.- 1" = 2' REVIEWED FOR CODE COMPLIANCE APPROVED DEC 0 6 2019 City of Tukwila BUILDING DIVISION RECEIVED CITY OF TUKWILA NOV 2 2 2019 PERMIT CENTER FOOTING DRAIN NOTES 1. F007ING DRAINS TO BE 4" PERFORATED PVC IN 3/" OR 1-Y2" WASHED ROCK WRAPPED W/ MIRAFI 1401V OR APPROVED EQUAL AND INSTALLED AT A SLOPE OF 0.00 2 CLEANOWS /N SIDEWALKS OR DRIVE AISLES SHALL HAVE CAST IRON RING AND COVER SET FLUSH WITH FINAL GRADE. J. CLEANOUTS IN SOFT AREAS TO RECEIVE CONCRETE COLLARS 4. BENDS, WYES ETC. (AS NECESSARY) TO BE DE7ERM/NED BY CONTRACTOR. 5. F0071NG DRAINS TO BE LAID FLAT OR WITH P05171VE SLOPE TOWARDS CONNEC7101V TO PROPOSED STORM SYSTEM. 6. CLEANOW7S SHALL BE PROVIDED EVERY f00' OR 135" IN DIRE07IONAL CHANGE. I UNDERGROUND UTILITY NOTE UNDERGROUND U77LI77ES ARE SHOWN IN 7HE APPROXIMATE LOCATION. THERE /S NO GUARAN7EE 7HAT ALL U77UTY LINES ARE SHOWN, OR THAT 7HE LOCA770N, SIZE AND MA7ER/AL /S ACCURATE: 7HE CONTRACTOR SHALL UNCOVER ALL INDICATED PIPING WHERE CROSSING INTERFERENCES, OR CONNEC77ONS OCCUR PRIOR TO 7RENCHING OR EXCAVATION FOR ANY PIPE OR S7RUC7URES, TO DETERMINE AC77JAL LOCA77ONS, SIZE AND MA7ER/AL. THE CONTRACTOR SHALL MAKE THE APPROPRIATE PROVISION FOR PR07EC77ON OF SAID FAC/U77ESS, THE CON7RACTOR SHALL N077FY ONE CALL AT 8-1-1 (WASH/NGTON811.COM) AND ARRANGE FOR FIELD LOCA77ON OF EAIS77NO FACIL177ES BEFORE CONSIRUC770N. 25 CENTRAL WAY, SUITE 400, KIRKLAND, WA 96033 P: 425.216A051 F: 415.216A052 WW W .THEOLUELINEGROUP.COM SCALE.• AS NOTED PROJECT MANAGER: CHRIS7OPHE7? A MILLER, PE PROJECT ENGINEER: ✓ON L. KOEAFGEN, PE DESIGNER: NADIA KROUMOVA ISSUE DATE:' 1112012019 z 0 N It gO S Q a 0 Z p l 2 ( T N Ol, N 4 lt� q u1 4j En •J La Q 0 U ap"ER y WAS ti U O p z _ �p 950D �v SlONALR �G\2 11121119 JOB NUMBER: I E_ 163 SHEET NAME: VT•02 BHT 7 OF 7 S�Op�o 1 max L e�ckS2pOF 0 ACTIVE PRESSURE = 45 x (H+D) pcf PASSIVE PRESSURE = 350 x D pcf (RS. =1.5) -�� LOADING DIAGRAM -SLOPED BACKSLOPE _____ ACTIVE PRESSURE = 35 x (H+D) pcf 9 PASSIVE PRESSURE = 350 x D pcf (F.S. = 1.5) LOADING DIAGRAM - LEVEL BACKSLOPE LEVEL BACKSLOPE \ LAGGING PER PLAN 8 PILE SECTION EDGE OF CRITICAL ROOT ZONE TIMBER LAGGING PER PLAN. 4 OUTSIDE FACE OF DETENTION VAULT CONCRETE WALL. \\\ EDGE OF WATERPROOFING 11, 2" min PERARCH'L. ) UON AUGER PER PLAN. CENTER STEEL PILE IN HOLE. wM 1.2 SLOPED BACKSLOPE AT SOME LOCATIONS TOP OF PILE ELEV. PER SCHEDULE BOTTOM OF EXCAVATION ELEVATION PER SCHEDULE LEAN CONCRETE PER GEN. NOTES AUGERCAST PILE AND W SECTION PER PLAN. BOTTOM OF PILE ELEV. PER SCHEDULE CONTRACTOR OPTION: LOCATE FACE OF PILE 2" MAX BACK FROM OUTSIDE FACE OF CONCRETE WALL TO ALLOW FOR PILE DEFLECTION AND PLACEMENT OF DRAIN AND DRAINAGE MAT, CODE REQUIREMENTS: ALL MATERIALS, WORKMANSHIP, DESIGN AND CONSTRUCTION SHALL CONFORM TO THE DRAWINGS, SPECIFICATIONS, AND THE REQUIREMENTS OF THE INTERNATIONAL BUILDING CODE, 2015 EDITION (AS AMENDED BY THE WASHINGTON STATE BUILDING CODE DATED JULY 1, 2016). REFERENCE DOCUMENTS: A. GEOTECHNICAL REPORT BY PANGEO INC, PANGEO PROJECT NO.17-211 DATED AUGUST 7, 2017, B. TEMPORARY SHORING RECOMMENDATIONS BY PANGEO INC, PANGEO PROJECT NO.17-211.200 DATED SEPTEMBER 12, 20% B. EXISTING CONDITIONS PLAN BY THE BLUELINE GROUP AND DATED SEPTEMBER 30, 2019. C. ROAD AND STORM PLAN BY THE BLUELINE GROUP AND DATED SEPTEMBER 30, 2019. D. DETENTION VAULT STRUCTURAL DRAWINGS St-S4 BY SITE STRUCTURES AND DATED SEPTEMBER 24, 2019. DESIGN LOADS: THE SOIL PRESSURE DIAGRAMS SHOWN ON THIS SHEET WERE USED FOR THE SHORING DESIGN; THE DIAGRAMS ARE BASED ON THE REFERENCED GEOTECHNICAL REPORT. SUBMITTALS: SHOP DRAWINGS SHALL BE SUBMITTED TO THE ENGINEER PRIOR TO ANY FABRICATION OR CONSTRUCTION FOR ALL STRUCTURAL ITEMS INCLUDING THE FOLLOWING: STRUCTURAL STEEL AND CONCRETES. PROPOSED EXCAVATION AND SHORING SEQUENCE SHALL BE ALSO SUBMITTED TO THE ENGINEER FOR REVIEW. SHOP DRAWINGS SHALL ALSO BE SUBMITTED TO THE ARCHITECT AND BUILDING DEPARTMENT. INSPECTION: CONTINUOUS INSPECTION IS REQUIRED OF THE GEOTECHNICAL ENGINEER FORTHE DRILLING OF PILE HOLES, AND INSTALLATION OF LEAN MIX AND SOLDIER PILES. THE GEOTECHNICAL ENGINEER SHALL MAINTAIN A RECORD OF SOIL CONDITIONS ENCOUNTERED AS WELL AS A RECORD OF ALL PILE DEPTHS, AND QUANTITY OF LEAN MIX PER PILE. COPIES OF PILE INSTALLATION FIELD INSPECTION REPORTS SHALL BE SUBMITTED TO THE BUILDING DEPARTMENT. INSPECTION BY A QUALIFIED TESTING AGENCY SHALL BE PERFORMED FOR CONCRETE AND STEEL PLACEMENT, AND STEEL FABRICATION. ALL SPECIAL INSPECTIONS SHALL BE IN ACCORDANCE WITH IBC SECTION 1704. SPECIAL INSPECTORS SHALL BE WABO CERTIFIED. UTILITY LOCATION: THE SHORING CONTRACTOR SHALL DETERMINE THE LOCATION OF ALL ADJACENT UNDERGROUND AND OVERHEAD UTILITIES PRIOR TO DRILLING PILE HOLES, OR CUTTING OR DIGGING IN STREETS OR ALLEYS. THE STRUCTURAL AND GEOTECHNICAL ENGINEERS SHALL BE NOTIFIED OF ANY INTERFERENCE WITH PROPOSED PILE LOCATIONS. EXISTING CONDITIONS: CONTRACTOR SHALL VERIFY ALL DIMENSIONS AND LOCATION OF EXISTING STRUCTURES AND UTILITIES PRIOR TO FABRICATION AND INSTALLATION OF ANY STRUCTURAL MEMBERS. CONTRACTOR SHALL NOTIFY ENGINEER OF ALL DISCREPANCIES IN DIMENSIONS AND FIELD CHANGES PRIOR TO FABRICATION AND INSTALLATION. CONCRETE: CONCRETE WORK SHALL CONFORM TO ALL REQUIREMENTS OF THE INTERNATIONAL BUILDING CODE. CONCRETE STRENGTHS SHALL BE VERIFIED BY STANDARD CYLINDER TESTS, UNLESS APPROVED OTHERWISE. LEAN CONCRETE SHALL ATTAIN A 28-DAY STRENGTH OF fc= 500 psi AND SHALL CONTAIN NOT LESS THAN 1 1/2 SACKS OF CEMENT PER CUBIC YARD OF CONCRETE. AS AN ALTERNATIVE TO THE ABOVE, THE CONTRACTOR CAN SUBMIT CONCRETE MIX DESIGNS TO THE STRUCTURAL ENGINEER FOR REVIEW ONE WEEK PRIOR TO PLACING ANY CONCRETE. THE ALTERNATIVE MIX DESIGN WILL BE REVIEWED FOR CONFORMANCE TO ACI 318 CHAPTER 5. STRUCTURAL STEEL DESIGN FABRICATION AND ERECTION SHALL BE BASED ON THE FOLLOWING A.I.S.C, SPECIFICATIONS AND CODES: 1. SPECIFICATION FOR STRUCTURAL STEEL BUILDINGS-ANSI/AISC 36M5. 2. CODE OF STANDARD PRACTICE FOR STEEL BUILDINGS AND BRIDGES -AISC 303-05. STRUCTURAL STEEL SHALL CONFORM TO THE FOLLOWING REQUIREMENTS: TYPE OF MEMBER ASTM SPECIFICATION EY W- SHAPES A992 50 ksi SAWN LUMBER SHALL CONFORM TO "GRADING AND DRESSING RULES," WEST COAST LUMBER INSPECTION BUREAU, LATEST EDITION. TIMBER LAGGING SHALL BE 4 x 12 HEM -FIR #2 AND PRESSURE TREATED WITH WATERBORNE PRESERVATIVES IN ACCORDANCE WITH AWPA STANDARD Ut-11. TREATED MEMBERS THAT HAVE BEEN CUT OR DRILLED SHALL BE FIELD TREATED WITH (2) COATS OF THE SAME PRESERVATIVE. CONCRETE PILE PLACEMENT TOLERANCES: 1/2" OUTSIDE PERPENDICULAR TO SHORING LINE 1/2" INSIDE PERPENDICULAR TO SHORING LINE 3" ALONG SHORING LINE PLUMBNESS SHALL BE TO WITHIN 1 / OF THE LENGTH (UP TO 3" MAXIMUM) BASED ON THE TOTAL LENGTH OF THE PILE. HOLE DRILLING AND GENERAL EXCAVATION SHALL BE PERFORMED WITHOUT LOSS OF GROUND AND WITHOUT ENDANGERING PREVIOUSLY INSTALLED PILES. THIS MAY INVOLVE CASING THE HOLES OR OTHER METHODS OF PROTECTION FROM CAVING. REFER TO THE GEOTECHNICAL REPORT FOR RECOMMENDED HOLE DRILLING PROCEDURE. PILE PLACEMENT: ALTERNATE PILES SHALL BE PLACED AND COMPLETED SO THAT AT LEAST 24 HOURS IS ALLOWED FOR THE CONCRETE TO SET PRIOR TO DRILLING ADJACENT PILES. TIMBER LAGGING SHALL BE INSTALLED AS SOIL EXCAVATION PROCEEDS. CONTRACTOR SHALL LIMIT THE AMOUNT OF EXPOSED SOIL WITHOUT LAGGING TO AVOID LOSS OF SOIL. THE MAXIMUM HEIGHT OF UNLAGGED CUT FACE SHALL BE AS RECOMMENDED BY THE GEOTECHNICAL ENGINEER. THE GEOTECHNICAL ENGINEER WILL MONITOR AND COMMENT ON THE PERFORMANCE OF TEMPORARY CUTS PERIODICALLY DURING CONSTRUCTION. LAGGING IS TO BE PLACED IMMEDIATELY AFTER EXCAVATION IS COMPLETE, NO PORTION OF AN EXCAVATED FACE IS TO BE LEFT UNSUPPORTED BETWEEN WORK SHIFTS. VOIDS BETWEEN LAGGING AND SOIL SHALL BE BACKFILLED PER GEOTECHNICAL ENGINEER'S RECOMMENDATIONS PRIOR TO BEGINNING EXCAVATION ON IMMEDIATE LOWER LIFT. DRAINAGE BEHIND THE WALL MUST BE MAINTAINED. LAGGING SHALL BE GAPPED 1116, TO 1/8", PER GEOTECHNICAL ENGINEER'S RECOMMENDATIONS, TO PERMIT SEEPAGE. SHORING MONITORING: A SYSTEMATIC PROGRAM OF OBSERVATION SHALL BE CONDUCTED PRIOR TO AND DURING THE PROJECT EXECUTION TO DETERMINE ANY EFFECT OF CONSTRUCTION ON ADJACENT FACILITIES AND STRUCTURES (INCLUDING ADJACENT UTILITY POLES) IN ORDER TO PROTECT THEM FROM DAMAGE OR DISPLACEMENT. SEE REFERENCED GEOTECHNICAL DOCUMENTS FOR MONITORING REQUIREMENTS. ALL SLOPES SHALL BE PROTECTED IN ACCORDANCE WITH THE RECOMMENDATIONS OF THE GEOTECHNICAL ENGINEER. SURFACE DRAINAGE AROUND THE EXCAVATION SHALL BE CONTROLLED BY THE CONTRACTOR. CONTRACTOR SHALL BE RESPONSIBLE FOR ALL SAFETY PRECAUTIONS AND THE METHODS, TECHNIQUES, SEQUENCES OR PROCEDURES REQUIRED TO PERFORM HIS WORK, THE STRUCTURAL ENGINEER HAS NO OVERALL SUPERVISORY AUTHORITY OR ACTUAL ANDIOR DIRECT RESPONSIBILITY FOR THE SPECIFIC WORKING CONDITIONS AT THE SITE AND/OR FOR ANY HAZARDS RESULTING FROM THE ACTION OF ANY TRADE CONTRACTOR. THE STRUCTURAL ENGINEER HAS NO DUTY TO INSPECT, SUPERVISE, NOTE, CORRECT, OR REPORT ANY HEALTH OR SAFETY DEFICIENCIES TO THE OWNER, CONTRACTORS, OR OTHER ENTITIES OR PERSONS ATTHE PROJECT SITE. THE CONTRACTOR IS RESPONSIBLE FOR SELECTING THE APPROPRIATE EQUIPMENT, PROCEDURES AND SEQUENCING SUCH THAT THE SHORING CAN BE CONSTRUCTED IN ACCORDANCE WITH THE CONTRACT DOCUMENTS AND SUCH THAT ADVERSE IMPACTS INCLUDING EXCESSIVE GROUND MOVEMENT OR GROUND LOSS BEHIND THE SHORING WALL DO NOT OCCUR. GENERAL SHORING NOTES CODE COMPLIANCE APPROVCD DEC 06 2019 City of Tuhi!3 S ,JOHNSON BRAUND,N�. 15200 52nd Ave, South Suite 300 Seattle, WA 98188 Phone 206.766.8300 wmnv.johnsonbraund.com ARCHITECTURE INTERIOR DESIGN Greg L. AIIWne, AIA Jeffrey A. Williams, AIA MICHAEL NOUWENS' si.u.aur I Con:uIt,— 30. — 178th Shoreline, WA 98177 michael@nouwent-snuRuml.com P 206.546. 6 9-26-2019 0 G s w y t Z N w N o � z 0 .0 N 0 R a PROJECT #: 1905 DRAWN BY: CHECKED BY: MLN TEMPORARY SHORING NOTES and DETAILS %r3% H '-Al 0% PERMIT SUBMITTAL \II Tern 1/6" = 1'-0" Ir— EX TOPOGRAPHIC CONTOURS ARCH DOCUMENTS FOR CONSTRUCTION REQUIREMENTS porary Shoring Plan WITHIN THIS ZONE. m PILE SCHEDULE PILE MARK STEEL SIZE AUGER SIZE BOTTOM OF EXCAVATION TOP OF PILE ELEVATION BOT. OF PILE ELEVATION P1 W18x50 30'diam 311.67' 322' 295.25' P2 W18x50 30"diam 311.67' 325.5' 295.25' P3 W21 x 73 30" diam 311.67' 327.26 292.25' P4 W21 x 93 30" diam 311.6T 327.5' 291.25' P5 W21 x 93 30" diam 311.67' 327.6 291.25' P6 W21 x 73 30" diam 311.67' 327.5 292.25' P7 W18 x 50 30" diam 311.67' 325.5' 295.25' P8 W18 x 50 30" diam 311.67' 323.26 295,25' _t~F�.:,,aa�;�j—s�k�.,,�1�.^,5� REVIEWED FOR CODE COMPLIANCE APPROVED DEC 0 6 2019 City of Tukwila BUILDING DIVISION LEGEND SHORING PLAN NOTES Px PILE MARK PER SCHEDULE 1. SEE SHEET SH100 FOR GENERAL SHORING NOTES AND DETAILS. TEMPORARY SLOPE CUT (1.0H:1.0V MAX) 2. GRADE ELEVATIONS BEHIND SHORING WALL ARE BASED ON THE SURVEY AND CIVIL PLANS. IF ELEVATIONS IN FIELD ARE FOUND TO BE DIFFERENT THAN THOSE SHOWN, THE CONTRACTOR SHALL CONTACT THE VERIFY SLOPE W/ GEOTECH ENGINEER ENGINEER PRIOR TO EXCAVATION, DRILLING, FABRICATION AND INSTALLATION FOR POSSIBLE SHORING REDESIGN, 3. EXCAVATION GRADE ELEVATIONS SHOWN INSIDE OF THE VAULT ARE BASED ON ELEVATIONS SHOWN ON THE REFERENCED DETENTION VAULT STRUCTURAL DRAWINGS. IF EXCAVATION DIFFERS FROM THAT SHOWN 255' GRADE ELEVATION (AFTER SLOPE CUT WHERE APPLICABLE). VERIFY IN FIELD. ON PLAN, THE CONTRACTOR SHALL CONTACT THE ENGINEER FOR POSSIBLE SHORING REDESIGN. 4. THE CONTRACTOR SHALL VERIFY THE EXTENT AND LOCATIONS OF SITE UTILITIES, ANY UTILITIES THAT COULD INTERFERE WITH THE SHORING SCHEME SHOWN SHALL BE BROUGHT TO THE ATTENTION OF THE ENGINEER FOR POSSIBLE SHORING REDESIGN. 5. CONTRACTOR SHALL COORDINATE TOP OF PILE ELEVATIONS WITH EXTERIOR GRADES FOUND INFIELD. TOP OF PILE ELEVATIONS MAY NEED TO BE SLIGHTLY ADJUSTED TO MATCH ACTUAL GRADES, 6. PROVIDE BUFFER ZONE BEHIND SLOPE CREST, TYP. IN WHICH NO CONSTRUCTION OR TRAFFIC LOADING CAN OCCUR. ZONE WIDTH SHALL BE PER GEOTECHNICAL ENGINEER RECOMMENDATIONS. RECEIVED CITY OF TUKWILA NOV 2 2 2019 PERMIT CENTER JOHNSON BRAUND,N, 15200 52nd Ave. South Suite 300 Seattle, WA 98188 Phone 206.766,8300 wew.johnsonbraund.wm ARCHITECTURE INTERIOR DESIGN Greg L. Allwine, AIA Jeffrey A. Williams, AIA MICHAEL NOUWEN Structural consultant —Second Avenue North— Ed—, ds, WA 9802 mmnaeipnouwen:-m.oa„ratm www.nou ene5�D6.546.— 6.844 11-21-2019 G 0 o I w y zo a ww rn o w z c 0 N N .- ❑ Q N `o A N 5T I PROJECT #: 1905 DRAWN BY: CHECKED BY: MLN TEMPORARY SHORING PLAN %r.')"H200 PERMIT SET DESIGN CRITERIA GENERAL CONSTRUCTION NOTES DEFERRED SUBMITTALS VERTICAL LOADS ON VAULT LID: UNIFORM LIVE LOAD : = 150PSF *HS20 TRUCK WHEEL LOADS 13'-6" 14' to _30!— y TRACTOR FRONT AXLE = 8,000 Ib. 0 0 o SINGLE REAR AXLE = 32,000 Ib. FRONT (REAR REARI I? TRAILER 0 0 o SINGLE REAR AXLE = 32,000 Ib. TRACTOR TRAILER *FIRE TRUCK WHEEL LOADS 21'-0' FRONT AXLE = 20,000 Ib, 0 8 8 REAR AXLES 50,000 Ib. FRONT REARI I (DUAL TANDEMI ee 4'-6" *OUTRIGGER PAD POINT LOAD PER NFPA 1901: DISTRIBUTED OVER 18"x18" PAD @ 151-0" o/c. = 45,000 Ib, * DESIGN LIVE LOAD AND TRUCK WHEEL LOADS TO BE APPLIED INDEPENDENTLY AND IN COMBINATION WITH THE SOIL COVER DEAD LOAD, HATCH: H520 TRUCK WHEEL LOADS IMPACT & FATIGUE; DUE TO THE LOW SPEEDS OF THE SERVICE VEHICLES AND THE SOIL COVER OVER THE LID, INCREASES IN VEHICLE LOADS TO ACCOUNT FOR IMPACT & FATIGUE ARE NOT REQUIRED. SOIL COVER FOR LID DESIGN: PLANK MANUFACTURER SHALL BE RESPONSIBLE FOR DETERMINING THE SOIL COVER DEPTHS USED IN THE LID DESIGN BASED ON THE PERMITTED CIVIL DRAWING, VAULT AND FINISHED GRADE ELEVATIONS. SOIL COVER FOR SUBSTRUCTURE DESIGN: THE SUBSTRUCTURE WAS DESIGNED FOR A SOIL COVER OF 0.83FT MIN TO 3.48FT MAX OVER THE TOP OF THE LID. FOUNDATION DESIGN: FOUNDATION DESIGN 15 BASED ON THE FOLLOWING VALUES PROVIDED BY PANGEO IN THEIR REPORT DATED 08-07-17 ALLOWABLE BEARING PRESSURE: 4,000 PSF LATERAL EARTH PRESSURES ON DETENTION VAULT; DRAINED LEVEL BACKFILL AT REST CONDITION: 45 PCF EFW ACTIVE CONDITION: 35 PCF EFW SEISMIC PRESSURE COMPONENT: E = 8H PSF UNIFORM SATURATED SOIL DENSITY: 125 PCF SPECIAL INSPECTION PLAN GENERAL: SPECIAL INSPECTION BY A QUALIFIED INSPECTOR IS REQUIRED IN ACCORDANCE WITH THE 2015 IBC. QUALIFICATION: THE SPECIAL INSPECTOR SHALL BE A QUALIFIED PERSON WHO SHALL DEMONSTRATE COMPETENCE, TO THE SATISFACTION OF THE BUILDING OFFICIAL. REQUIRED VERIFICATION & INSPECTION: THE SPECIAL INSPECTOR SHALL PERFORM THE VERIFICATIONS & INSPECTIONS NOTED IN THE SCHEDULE BELOW INSPECTION & TESTING SCHEDULE TYPES OF WORK FREQ. 2015 IBC SECTION CAST IN, PLACE CONCi REINFORCING STEEL, PLACEMENT. P 1705.3 INSTALLATION & FASTENING OF PRECAST PANELS P 1705.3 PLACEMENT OF CONCRETE C 1705.3 VERIFYING USE OF REQUIRED DESIGN MIX P 1705.3 TESTING OF THE CONCRETE FOR SPECIFIED STRENGTH, AIR CONTENT AND SLUMP C 1705.3 SOILS VERIFICATION OF SOIL -BEARING CAPACITY: INSTALLATION OF DRAINAGE SYSTEM: C 1705.6 PLACEMENT & COMPACTION OF WALL BACKFILL: P 1705.6 FREQUENCY LEGEND C = CONTINUOUS P = PERIODIC SEE REFERENCES AND STANDARDS LISTED WITHIN THE VERIFICATION & INSPECTION SCHEDULE FOR MEANING OF PERIODIC AND CONTINUOUS INSPECTIONS. CERTIFICATE OF COMPLIANCE: THE SPECIAL INSPECTION AGENCY SHALL PROVIDE A FINAL LETTER CERTIFICATE OF COMPLIANCE STATING THAT THE REVIEWED WORK WAS COMPLETED IN ACCORDANCE WITH THE PERMITTED DOCUMENTS, SUBMITTAL OF REPORTS: ALL SPECIAL INSPECTION REPORTS AND TESTING REPORTS SHALL BE SUBMITTED TO THE OWNER, SITE STRUCTURES AND THE BUILDING OFFICIAL BY THE AGENCY PERFORMING THE INSPECTION OR TESTING. CODE: VAULT DESIGN AND CONSTRUCTION SHALL CONFORM TO THE PROVISIONS OF THE 2015 IBC AS ADOPTED BY THE CITY OF TUKWILA, WASHINGTON GENERAL DETAILS: CONSTRUCTION DETAILS NOT FULLY SHOWN OR NOTED SHALL BE SIMILAR TO DETAILS SHOWN FOR SIMILAR CONDITIONS. DISCREPANCIES: THE CONTRACTOR SHALL NOTIFY ENGINEER UPON FINDING ANY DISCREPANCY OR OMISSION IN THE DRAWINGS OR SPECIFICATIONS. SHORING & EXCAVATION: THE CONTRACTOR SHALL BE SOLEY RESPONSIBLE FOR ALL EXCAVATION PROCEDURES, INCLUDING LAGGING, SHORING AND PROTECTION OF ADJACENT PROPERTY, STRUCTURES, STREETS AND UTILITIES. WALL BACKFILL: PRIOR TO BACKFILLING VAULT WALLS THE CONTRACTOR SHALL HAVE PLACED THE LID PLANKS AND PROVIDED A MINIMUM OF 5 DAYS OF CURE ON THE PLANK VOID FILL. BACKFILL SOIL: WALL BACKFILL SHALL BE WELL GRADED FREE DRAINING SOIL FREE OF ORGANIC MATERIAL. BACKFILL SHALL BE PLACED IN LIFTS OF NO MORE THAN 8 INCHES AND COMPACTED TO WITHIN 907 OF THE SOILS MAXIMUM DRY DENSITY. ALL COMPACTION OCCURING WITHIN 5' OF THE WALL SHALL BE COMPLETED USING HAND OPERATED MACHINERY. CONCRETE CONCRETE REQUIREMENTS: LOCATION STRENGTH MAX W/C RATIO CURBS @ HATCH 4500PSI @ 28 DAYS 0.45 FTGS & GRADE SLAB 3000PSI @ 28 DAYS 0.53 PLANK VOID FILL TO MEET PLANK MFGR'S REQUIREMENTS* PLANK JOINT GROUT TO MEET PLANK MFGR'S REQUIREMENTS* * MINIMUM STRENGTH SHALL BE 3000PSI @ 28 DAYS. AIR CONTENT: CONCRETE EXPOSED TO WEATHER SHALL CONTAIN 5Y +/-i% ENTRAINED AIR. MIX DESIGN: SHALL BE BASED ON FIELD EXPERIENCE OR TRIAL MIXTURES IN CONFORMANCE WITH THE SPECIFICATIONS. MATERIAL REQUIREMENTS: CEMENT; ASTM C150, ADMIXTURES: ACI 301. AGGREGATES: ASTM C33, WATER: ASTM C94. EXPOSURE CATEGORIES: FREEZING THAWING FO SULFATE SO IN CONTACT w/ WATER W1 CORROSION PROTECTION C1 PLACING REQUIREMENTS: PLACING: PLACE CONCRETE AS NEARLY AS PRACTICABLE TO ITS FINAL POSITION TO AVOID SEGREGATION. DEBRIS: REMOVE ALL DEBRIS FROM FORMS PRIOR TO PLACING CONCRETE. CONSOLIDATION: CONSOLIDATE CONCRETE BY SUITABLE MEANS. THOROUGHLY WORK CONCRETE AROUND EMBEDDED ITEMS AND INTO CORNERS OF FORMS, CURING REQUIREMENTS CURING: CONCRETE SHALL BE MAINTAINED IN A MOIST CONDITION FOR A SUITABLE PERIOD OF TIME AFTER PLACEMENT. WEATHER CONDITIONS: ADEQUATE PRECAUTIONS SHALL BE TAKEN DURING HOT AND COLD WEATHER IN ACCORDANCE WITH THE SPECIFICATIONS. LID PLANK PLACEMENT: IN NO CASE SHALL THE LID PLANKS BE PLACED BEFORE THE WALLS HAVE BEEN ALLOWED A MINIMUM OF 3 DAYS OF CURE. WHEN AVERAGE AMBIENT TEMPERATURES ARE LESS THAN 50 DEGREES FAHRENHEIT, THE CONTRACTOR MUST ALLOW A MINIMUM CURE TIME OF 7 DAYS OR PROVIDE AN ADDITIONAL SET OF CYLINDERS TO BE BROKEN AT THE TIME OF LID PLACEMENT DEMONSTRATING A MINIMUM CONCRETE STRENGTH OF 1,000 PSI HAS BEEN REACHED. REINFORCING BAR MATERIAL REQUIREMENT: REINFORCING BARS: USE DEFORMED BARS CONFORMING TO ASTM A615, GRADE 60, EXCEPT AS NOTED ON THE DRAWINGS. FABRICATION AND PLACING REQUIREMENTS: BENDING: BARS SHALL BE BENT COLD. BARS PARTIALLY EMBEDDED IN CONCRETE SHALL NOT BE FIELD BENT UNLESS NOTED OR SHOWN OTHERWISE OR AUTHORIZED BY THE ENGINEER. PLACING: REINFORCEMENT SHALL BE SUPPORTED AND TIED TO PREVENT DISPLACEMENT BY CONSTRUCTION LOADS OR BY PLACING OF CONCRETE. MAXIMUM SPACING OF SUPPORTS SHALL BE V-611. CONCRETE COVER: MINIMUM CONCRETE COVER FOR REINF. SHALL BE AS FOLLOWS, UNLESS NOTED OTHERWISE: CONCRETE CAST AGAINST EARTH 3" CONCRETE CAST AGAINST FORMS AND EXPOSED TO EARTH 2" WET SETTINGS: REINFORCEMENT ANCHOR BOLTS, OR ANY EMBEDDED ITEM WITHIN THE CONCRETE, MAY NOT BE SET INTO THE CONCRETE AFTER IT HAS BEEN POURED WITHIN THE FORMS, LAP SPLICES: LAP ALL BARS 24" MIN UNLESS SHOWN OTHERWISE ON THESE DRAWINGS. THE FOLLOWING AREAS OF WORK SHALL BE CONSIDERED AS "DEFERRED SUBMITTALS" AS DEFINED IN THE 2015 IBC a. PRECAST PRESTRESSED HOLLOW CORE PLANK b. CONCRETE MIX DESIGNS. C. LW HATCH ASSEMBLY DRAWINGS ALL DEFERRED SUBMITTALS SHALL BEAR THE STAMP AND SIGNATURE OF A CIVIL ENGINEER LICENSED TO PRACTICE IN THE STATE OF WASHINGTON WHO HAS CURRENT DESIGN EXPERIENCE IN THE TYPE OF WORK REVIEWED. THE DEFERRED SUBMITTAL ITEMS SHALL NOT BE INSTALLED UNTIL THEIR DESIGN AND SUBMITTAL DOCUMENTS HAVE BEEN REVIEWED BY THE ENGINEER OF RECORD, LW HATCHES DOUBLE LEAF SPRING LOADED SOLID ACCESS HATCHES SHALL BE AS FABRICATED BY LW PRODUCTS COMPANY, INC, 8333 - 219TH ST. BE, BLDG A, WOODINVILE, WA 98072 SUPPLIER SHALL PROVIDE ALL COMPONENTS NECESSARY TO INSTALL AND SECURE THE GRATING IN PLACE & SHALL PROVIDE SHOP DRAWINGS DETAILING ALL COMPONENTS OF THE INSTALLATION ALONG WITH DOCUMENTATION SUBSTANTIATING THEIR CAPACITY TO SUPPORT THE DESIGN TRUCK WHEEL LOADS. HOLLOW CORE PLANK SCOPE OF WORK: THE WORK INCLUDED IS THE DESIGN, MANUFACTURE AND DELIVERY OF PRECAST PRESTRESSED CONCRETE UNITS. DESIGN PLANK FOR THE MOST CRITICAL OF THE LOADING CONDITIONS AS SHOWN WITHIN THE DESIGN CRITERIA NOTE. THE MANUFACTURER SHALL SUBMIT STRUCTURAL CALCULATIONS AND PLACEMENT DRAWINGS SIGNED BY A WASHINGTON STATE REGISTERED STRUCTURAL ENGINEER FOR REVIEW PRIOR TO FABRICATION, THE MANUFACTURER SHALL INSTALL ALL BLOCK OUTS REQUIRED FOR STRUCTURAL CONNECTIONS AS INDICATED ON THESE DRAWINGS. NO OTHER PENETRATIONS ARE ALLOWED WITHOUT THE PRIOR APPROVAL OF THE PLANK MANUFACTURER, ALL HOLLOW CORE JOINTS SHALL BE GROUTED IN ACCORDANCE WITH THE MANUFACTURER'S RECOMMENDATIONS. PRECAST CATCH BASIN BASE SPECIFICATIONS: PRECAST CATCH BASIN BASE SHALL MEET ASTM C478 AND THE APWA/WSDOT STANDARD SPECIFICATION FOR PRECAST CONCRETE MANHOLE SECTIONS. MATERIALS: a. REINFORCING STEEL Fy=6OKSI MINIMUM b. CONCRETE f'c=4,000PSI MIN @ 28 DAYS MINIMUM REQUIREMENTS:: CIRCUMFERENTIAL WALL THICKNESS SHALL BE NO LESS THAN 5" THICK AND SHALL HAVEA MINIMUM OF 0.12 SQ. IN/FT OF REINFORCING STEEL HORZ AND VERT PLACED AT THE CENTER OF THE WALL, BASE THICKNESS SHALL BE NO LESS THAN 6" THICK AND SHALL HAVE A MINIMUM OF 0.15 SQ. IN/FT OF REINFORCING STEEL :IN EACH ORTHOGONAL DIRECTION PLACED AT THE CENTER OF THE SLAB. ADD #5x48" DIAG EA — FACE AS SHOWN FILL WITH GROUT AS DIRECTED BY PRECAST PLANK MFGR. CONT. BACKER ROD IF REQ'D. TYP PLANK JOINT DETAIL S1 SCALE 1"=1'-0" SEE END PLAN KEYNOTES FOR WALL REINF. 45 DOWEL TO MATCH WALL VERT REINF SPACING, SEE 7/54 FOR PLACEMENT REQMTS. GRADE SLAB REINF SEE FOUNDATION PLAN N45 CONT. #5@12"0/c 4 KNEEWALL FTG DETAIL S1 SCALE 3/4"4-0" T-6" MAX AT SKEWED PIPE d _-----______________s- a==z -_-_ --- ipt ail 11 -------- - ------ -_---�. d 'J I I Y I ADD I3)-#6x12'-0"@ 611o/c EA FACE ABOVE & BELOW OPNG ADD ONE #7 VERT FULL HEIGHT REINF BAR EACH SIDE OF BLOCKOUT FOR EA VERT BAR CUT AT BLOCKOUTS WALL REINF @ PIPE PENETRATION #4@18"o/c EA WAY N —IN N C)NC DOBIE OR CHAIR TYP GRADE SLAB SECTION S1 SCALE 1-1/2"=1'-0" �Q MEWED NOV ! y 2019 REID MIDDLETON, INC. I4)-#6 PLANK DOWELS PLACED AT MIDDEPTH OF SLAB. 12-112" THICK CAST IN PLACE CONCRETE SLAB SHOWN SHADED. PVA 1 A 'r01 (_5_7� LID REINF @ MANHOLE S1 REVIEWED FOR CODE COtiF.PLIANCE R �(`I.n-1 I o0 36 2019 'II! � I APPROVED q , vim. nl40 DEC o 6 2019 REID MIDDLE i ON, INC. I City Of Tukwila i RLIILDING DIVISION rol CUT NO MORE THAN 2 VERT BARS :ON )D ONE VERT, EA DE OF BLOCKOUT 'D 12I-#5x4'-0"@411o/c AR INSIDE FACE WALL ABOVE OCKOUT XiPj1•4i212 MAX 20" WIDE BLOCKOUT TOP OF GRADE SLAB - FOOTING NON SHRINK GROUT VOID FILL a O r 2E W 2 y cy z C. Q U_ N C Uj j u U. _ W N y y a co cc oc 'T Cr N a w c 2 11) 0 W E Y 16 m 2PiZW ® Q c 18 0 3 , Q 20744 co) _j !— CL "F:wetiT e�y �7sn3+ C L0' ' 8" 1 L 128'-0" 8" 7'-6" 36'-6" 4'-0" 76'-0" 4'-0" _ 1 i 5 i 2 S4 S4 2 F24x12 F24x12 ------6---I --------'-------------------------------"---- 3 --; -r- ------------------------------------------------------i I 1 - ( T? 1 IBOV=312.62 I _ TYP @ CELL 1 PERIMETER I ( I 1 CELL IWALLS ,�U �______- I �- ; I F30x12 ° _ IBOV=312.24 1U IBOV=312.24 o 3A I i— 5° THICK CONCRETE r I s o" SLAB ON GRAgE L_ 5 s4 e 4 F38x126 F30x12 I 1 o = F38x12 - - - - - ---------- ------- ------------------------------------------------------------------------------------------------------- O + <V v 9 ------------- ---------- A ------------------_ _ __ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ __ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ v _ _ _ _ _ _ _ _ — — _ _ _ _ _ _ _ _ _ _ — — — — — — — _ _ — — — — — _ _ — _ _ _ _ — _ _ — — — — — — — — — — — — — — — 1 S4 2 2 I I 1 I S4 � CELL 2 7'-6" P _ S4 ." IBOV=312.24 I IN IBOV=312.24 6 1 Im — F30x12 I = X o C IU_ F30x12 r ------ , I r------- F I i I I I IBOV=312.62 L - - - - - ------- ' d u 1 - TYP @ CELL 2 _ --E = PERIMETER o 1 i � o " I F28x12 ;;- WALLS- 1 _ ---F28x12 -------------------- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - --------6 ---- -------------------------------------- ----- ----- - T----- -- A S4 2 Zll A S S4 8 8 - _.... 44'-0" 4'-0" _ 401-011 .._. I 121-0" _ 28'-0" 5 VAULT FOUNDATION PLAN 2' 8' SCALE 3/16" = 1'-0" 0' 4' 16, ALT. 24" #5 x 30, TO MATCH HORZ. 1 #5@12"o/c HORZ & VERT ON BACK FACE OF WALL. DOWELS TO - - FOOTINGS ARE NOT REQUIRED AT ' - — THESE VERT BARS i 24L_ #5 X 30" 0 44"x24" CORNER BARS TO MATCH HORZ. TO MATCH HORZ WALL REINF TYP - — ALT. HOOK 0 #5@12"o/c HORZ &VERT ON #5@12"o/c HORZ & VERT ON BACK BACK FACE OF WALL. FACE OF WALL. DOWELS TO FOOTINGS ARE NOT REQUIRED AT DOWELS TO FOOTINGS ARE NOT REQUIRED AT THESE VERT BARS THESE VERT BARS WALL REINFORCING ON INSIDE. FACE WALL CORNER REINF, #5 x241lx24" CORNER BARS TO MATCH HORZ WALL REINF TYP PLAN KEYNOTES t 5" THICK CONCRETE SLAB ON GRADE REINF WITH #4@18"o/c EA WAY. PLACE ALL REINF AT MID -DEPTH OF THE SLAB. CAST GRADE SLAB IN A SINGLE POUR, SEE 2/51 FOR REINFORCING PLACEMENT DETAIL. 2. CAST IN PLACE CONCRETE WALLS TYPICAL AT THE INTERIOR & PERIM. OF THE VAULT. SEE WALL SECTIONS ON S4 FOR INFORMATION. PROVIDE ADDED REINF AT PIPE PENETRATIONS AS SHOWN IN 3/S1, PROVIDE REINF @ ALL WALL CORNERS AS SHOWN IN 1/S2, 3, THICKENED SLAB FOOTINGS TO BE CAST WITH THE GRADE SLAB. SEE WALL SECTIONS FOR SIZE & REINF UNO. 4. 5'-0" WIDE OPENING WITHIN THE INTERIOR WALL. SEE A/S4 FOR WALL REINFORCING @ THE OPENING. 5, PIPE INLET OR OUTLET TO VAULT. SEE CIVIL DWGS FOR PIPE DIAMETER, LOCATION & INVERT ELEVATION, SEE 3/61 FOR WALL REINF @ PENETRATION. ADDITIONAL REINF IS NOT REQUIRED FOR PIPES LESS THAN 84 PROVIDED THEY ARE PLACED BETWEEN THE TYPICAL WALL REINFORCING. 6. 8" THICK KNEE -WALL, REINF w/ #5@12"o/c HORZ. AND VERT. PLACED AT THE CENTER OF THE WALL. PROVIDE I2)45 HORZ AT THE TOP OF THE WALL & (2)-#5 VERT AT THE FREE ENDS OF THE WALL, EXTEND VERT BARS 11" INTO THE 12-1/2" THICK LID CLOSURE POUR. SEE 4/61 FOR FTG INFORMATION. 7, 484 CATCH BASIN BASE TO ACT AS SUMP. SEE 5/S4 FOR DETAILS 8, ULTRA BLOCK SHORING AT BASE OF EXCAVATION TYP ALONG THE SOUTH WALL OF THE VAULT. DESIGN BY OTHERS. 9. CANTILEVERED SOLDIER PILE WALL AND TIMBERR LAGGING TYP ALONG THE WEST WALL OF THE VAULT, DESIGN BY OTHERS. LEGEND IBOV INSIDE BOTTOM OF VAULT ITOP OF GRADE SLAB) CIP CONCRETE WALL, CONCRETE SPREAD FOOTING �— DIRECTION OF DOWNWARD SLOPE F24x12 24" WIDE x 12" THICK FTG SEE 1 & 3 F38x12 38" WIDE x 12" THICK FTG SEE 2154 F3Ox12 30" WIDE x 12" THICK FTG SEE 4/Si F28xI2 28" WIDE x 12" THICK FTG SEE to & REVIEVVED FOR CODE COMPLIANCE APPROVED /54 DEC 06 2019 City of Tukwila 3A/ 131RALDING DIVISION DIMENSIONS & ELEVATIONS THE CONTRACTOR AND HIS SUBCONTRACTOR SHALL BE RESPONSIBLE FOR VERIFYING ALL DIMENSIONS AND ELEVATIONS SHOWN ON THESE DRAWINGS WITH THE CURRENT PERMITTED SET OF CIVIL DRAWINGS, AND SHALL NOTIFY BOTH THE CIVIL & STRUCTURAL ENGINEERS IN WRITING OF ALL DISCREPANCIES BETWEEN THE CIVIL DWGS AND THESE DWGS PRIOR TO CONSTRUCTION. -I— C l�% Er vlF i 2019 III REID MIDDLETON, INC. Q v o�C 4 G Uj .- O 1- W ti cn m cn & C> W a U W V � W G C W W O W W fd cn co In Uj a m m 0) co m:1111 $2 O 0 a c c 0 We Y m c w z p 0 20744 60 J 1 SHEET: I C 8g ILJ'Y'" 32 PLANKS @ 4'-0" = 128'-0" 8" 46'-0' 80'-0" 21-0" 5 _.. — 9 1 S4 1 54 -_ �- - O ��'------=------ -------'- _______T_ _____' �__ _ _ __ ____ t_ _�___.... _____ __�__________ ___ _____________ _ —�__ _-_________ __ _ _____— - _�___�_______ ______________ ---'T _______ __T________ __---------- ____ e 7 i 4 -- ---- --- 12-112" THICK HOLLOW CORE PLANK LID. TOP OF LID EL= 321,74 — 1 S1 7 9 a r 5 II— --- -- --- i - ------ -------------- -- ,--_-"-_"- ---------- -------- - ---- -- T n--- ❑-- _ °n°°°°----- -------- - _ 11 Tro _____________ 0 __ _________�________ _ ______ Ij _______ I i6 0 �� _ O i D. ❑ ❑ _ _- IL ❑ ❑ ❑ ❑ ❑ =L___T=_L ❑ ❑ ❑ ❑ ______ _______�-_ ❑ ❑ _____________�___ ❑ ❑ �D ❑ ❑ ❑ _ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ i❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ IC. ❑ ❑ ❑ _____________ ❑ 0 __ ❑ L1 1❑ ❑ ❑ ❑ ❑ ❑ ________ ❑ ❑ ❑ ❑ I i s1 ITOV=320.70 TYP THROUG OUT VAULT. j i 4 ` y J 3 S4H - " ❑ ❑ 1 2 2 d m ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ ❑ n ❑ ❑ ❑ ❑ ❑ ❑ ❑ _--- _r ❑ ❑ _J__-. ,ram____ L ❑ ❑ ❑ ❑ ❑ ❑ ❑ _____________ __________r____________________ ❑ ❑ 8 ❑ ❑ __ _________ u ❑ I❑ ❑ _ ___________________________ i❑ ❑ ❑ ❑ ❑ ❑ ________ ❑ ❑ ___________________ ❑ ❑ ❑ ❑ _ _ ___ _____-----_-____ 10 ❑ ❑ ❑ ________ ❑ - __ ................ 1A 9 S4 5 Si ..............:A, u.v.ioo.v 3 S4 5 46' 3" 42' 9" 10' O" 29'-011 VAULT LID PLAN 2' 8' SCALE 3/1611 = 1'-0" 0' 4' 16' 5x10 HATCH 5x10 HATCH 5x10 HATCH ���- ��i. illilllli _��� �li I11- #4 TIES @ 51o/c. — 8" THICK CURB REINF w/ PLACE FIRST TIE w � FREINF o #5@12"o/c H. & V. PLACED NO MORE THAN N � AT THE CENTER OF THE 2-1/2" FROM w URB WALL SUPPORT, � } 5@12"o/c > H. & V. PLACED AT LID STRUCTURE. THE CENTER OF AS OCCURS THE WALL EXTEND VERTICAL ' EXTEND VERTICAL CURB VERT. REINF CURB VERT, REINF m ® INTO CLOSURE POUR INTO CLOSURE POUR (41-#6 TOP & BOT 1' O" LID STRUCTURE. KNEE WALL OR SEE LID PLAN PERIMETER WALL 1 SLAB BEAM @ OPNG 2), BM SEAT DETAIL 3 TYP CURB @ OPNG S3 SCALE 1 1 0 S3 SCALE i i 0 63 SCALE 1`4-011 PLAN KEYNOTES 1. LW PRODUCTS 5FTx1OFT DOUBLE LEAF SPRING LOADED SOLID ACCESS HATCH. HATCH SHALL BE RATED FOR H520 TRUCK WHEEL LOADING. SEE CIVIL DWGS FOR ADDITIONAL REQUIREMENTS. SEE 2 & 3/S3 FOR TYP CURB DETAILS, SEE CIVIL DWGS FOR LADDER LOCATIONS, 2. HATCHED AREA REPRESENTS 12" WIDE x 12-1/2" THICK CAST IN PLACE CONCRETE BEAM. SEE 1/S3. 3, ADD (3l-#6x15'-0" @ 311o/c WITHIN THE WALL ON EACH FACE & AT THE TOP OF THE WALL. PLACE BAR AS SHOWN ON THE PLAN. 4, 12-1/2" THICK PRECAST HOLLOW CORE PLANK. SEE DESIGN CRITERIA NOTES ON SHEET S1 FOR PLANK LOADING REQMTS. 5. PIPE INLET OR OUTLET TO VAULT, SEE CIVIL DWGS FOR PIPE DIAMETER, LOCATION & INVERT ELEVATION. SEE 3/91 FOR WALL REINF @ PENETRATION. ADDITIONAL REINF IS NOT REQUIRED FOR PIPES LESS THAN 84 PROVIDED THEY ARE PLACED BETWEEN THE TYPICAL WALL REINFORCING. 6. 24" DIAMETER OPENING w/ KNEEWALL TO ACCEPT RISERS, LADDER, RING AND LOCKING MANHOLE COVER PER CIVIL DRAWINGS. SEE 5/51 FOR LID REINFORCING AT MANHOLE OPENING. 7. PROVIDE BLOCKOUTS IN THE EDGE CELL OF THE PLANK PARALLEL TO THE PERIMETER VAULT WALLS. LOCATE BLOCKOUTS APPROXIMATELY AS SHOWN ON THIS PLAN, SEE WALL SECTIONS FOR REINFORCING. 8. POUR SLOTS IN THE TOP OF THE PLANK. MANUFACTURER TO PROVIDE A MINIMUM OF 2 SLOTS @ EACH END OF EACH PLANK. SEE WALL SECTIONS FOR REINF. 9. 12"0 OPNG THRU LID FOR ACTIVE VENTILATION DURING VAULT SERVICING. SEE 9154 FOR LID REINF @ OPNG. 10, CANTILEVERED SOLDIER PILE WALL AND TIMBERR LAGGING TYP ALONG THE WEST WALL OF THE VAULT. DESIGN BY OTHERS. LEGEND ITOV INSIDE TOP OF VAULT LID (TOP IF G 1NC.1F�L� FOR tJ� � G���� LIANCG 01C 06 2019 City of Tukwila BLJIL')!P'G DIVISION CONSTRUCTION LOADS THE VAULT LID HAS BEEN DESIGNED TO CARRY THE "DESIGN LOADS° ONLY AFTER VAULT CONSTRUCTION IS COMPLETE, ALL DESIGN CONCRETE AND GROUT STRENGTHS HAVE BEEN ACHIEVED, AND ALL COVER HAS BEEN PLACED OVER THE VAULT WITHIN THE LIMITS SPECIFIED ON THIS DRAWING."BOBCAT" OR OTHER LIGHT EQUIPMENT SHALL BE USED FOR PLACEMENT OF MATERIALS OVER THE VAULT LID. ALTERNATIVELY, ALLOWABLE UNIFORM LOADS ON THE BARE SLAB CAN BE OBTAINED FROM THE PLANK MFGR. o ca z r Q 0 W a N O Q � U � U a ac Q O a o �— W O y VJ ca CD g O W a ccO W fUA C W C V' ca ? G C> W W W � Wca S2<,W.cc 121111 N � N 0 0 0 0 0 0 a z m 0 W aJ Y i to SO 0 sum 0 g! n >� 0 2c 5 J G � Lu 0 J as Q D MEWAVE NOV 1, 4 I2019 DD REID MIDDLETON. INC, I �. TYP WALL SECTION to TYP WALL SECTION TYP WALL SECTION 3 TYP WALL SECTION 54 SCALE 1/2"=11-011 SCALE 1/2 S4 I�_' �� i II .Oi►���� 484 TYPE 2 CATCH BASIN BASE ROLLED ALUMINUM ANGLE 1-1l2x1-1l2xi/8 w/ (ii)-1/41101-3/41' LONG HEX HEAD STAINLESS STEEL SIMPSON TITEN CONCRETE SCREWS SPACED AS SHOWN. PROVIDE CRL BITUMINOUS COATING TO ALL ANGLE SURFACES IN CONTACT WITH THE CONCRETE. GRATING @ SUMP VAULT PERIMETER WALL 12) #4 CIRCULAR TIES CAST FTG & GRADE SLAB AGAINST PRECAST BASE. #3x811x2411 @ 12110 /c ALONG EDGE OF SUMP IN RADIAL PATTERN 411 DEEP x 21110 TRAFFIC RATED VENT COVER. CONCRETE BLOCK DIRECTLY BELOW — DO NOT FASTEN VENT COVER VENT COVER, OR RIM TO VENT PIPE. TRAFFIC RATED STRUCTURAL - FILL. 12110 PVC VENT PIPE THRU WALL VENT PIPE DETAIL S4 SCALE 1"=i'-0" VAULT LID VAULT WALL DOWEL & VERT REINF TO BE PLACED IN LINE DOWN THE LENGTH OF THE WALL e FIBERGLASS GRATING- ------ ' COVER & SUPPORT ANGLE IIIi — VOLCLAY RX-102 WATERSTOP IIIII1 ET AT THE PERIMETER OF THE DOWEL w/o VERT FTG TO VERT WALL SUMP TO SLAB INTERFACE > BAR SPLICE - WALL DOWEL REINF 48 m Lu m 3° MAX DOWEL & VERT REINF TO BE PLACED IN N w LINE DOWN THE LENGTH OF THE WALL 4811 CATCH — BASIN BASE. YT SECTION @ SUMP 5 SUMP DETAIL 54 SCALE 314114-011 DOWEL w/o VERT ---/ FTG TO WALL J J VERT WALL BAR SPLICE DOWEL REINF TYP FTG DOWEL PLACEMENT DETAIL 54 SCALE i161'-0'1 3A TYP WALL SECTION WALL REINF @ OPENING 54 SCALE-1/2"=1'-0° �4J SCALE 1/2"=1'-0° 4'-0" WIDE PLANK 12'1 #4 x=1411— SET @ CENTER OF VOID PLAN VIEW 36" #5x 18n 1 — CLOSURE TO 36" DOWELS @ 96 o/L c, #5x 1811 = 3611 CLOSURE TO WALL #5 x 24" 1 LID TO PLAN VIEW DOWELS @ 3611o/c. CLOSURE DOWELS @ EA PLANK. rHOLLOW CORE 11-011 L I PLANK #5 @ CENTER OF VOID PERIMETER WALL WALL VERT REINF EXTENDING INTO CLOSURE 1211 #4 x 11411 SET @ ENTER OF VOID WALL SECTION GENERAL KEYNOTES 101, PROVIDE CONTINUOUS 411 PVC WATERSTOP - RIBBED WITH CENTERBULB AT THE BASE OF ALL PERIMETER WALLS. INSTALL WATERSTOP IN ACCORDANCE WITH ALL MANUFACTURER'S INSTRUCTIONS. PLACE AT THE CENTER OF THE WALL 102. 12-1/2" THICK PRECAST HOLLOW CORE PLANK, 103, FINISHED GRADE, ELEVATION VARIES, SEE DESIGN CRITERIA ON SHEET 91 FOR APPROXIMATE SOIL DEPTHS OVER THE VAULT LID IN ADDITION TO THE CIVIL DWGS FOR FINAL GRADE ELEVATIONS, 104. 44 PERFORATED PVC FTG DRAIN MIN IE=313.12 WRAPPED IN 12"x1211 MINIMUM DRAIN ROCK BEDDING & FILTER FABRIC. ROUTE DRAIN TO DISCHARGE POINT AS SHOWN ON THE CIVIL DWGS, 105. W. R. MEADOWS MEL-DRAIN SOIL SHEET DRAIN SYSTEM TO BE INSTALLED IN ACCORDANCE WITH MANUFACTURERS INSTRUCTIONS, TIE TO 4" DIA FTG DRAIN OR HIGH PROFILE TOTAL -DRAIN. 106. PLANK TO BEAR 3" MINIMUM ONTO THE TOP OF THE CONCRETE WALL. SEE PLANK MANUFACTURER'S DRAWINGS FOR FINAL BEARING LENGTH, INSTALL BEARING PAD AS DETAILED ON THE PRECAST PLANK PLACEMENT DRAWINGS. 107, SEE FOUNDATION PLAN FOR SLAB REINFORCING. 108, CANTILEVERED SOILDIER PILE WALL. DESIGN BY OTHERS, 109. COMBINATION TOTAL DRAIN HIGH PROFILE SECTION TO RUN ALONG THE FULL LENGTH OF THE WALL. TIE TO 4" DIAMETER FTG DRAIN AT THE TYPICAL WALL SECTION w/ UNIVERSAL OUTLET FITTING, 110. UNTRABLOCK SHORING. DESIGN BY OTHERS, WALL SECTION REINFORCING KEYNOTES 201. 8" THICK CONCRETE WALL REINF w/ #5@121'o/c HORZ & VERT. PLACE VERT REINF NEAR THE INSIDE FACE OF THE WALL. LAP ALL HORZ BARS 24" MIN @ SPLICE LOCATIONS. PROVIDE (2)-#5 CONT HORZ BARS @ THE TOP OF THE WALL. EXTEND VERT REINF 11" MIN INTO THE LID CLOSURE POUR WHERE POSSIBLE. 202. 8" THICK CONCRETE WALL REINF w/ #5@i211o/c HORZ & VERT, PLACE VERT REINF @ THE CENTER OF THE WALL. LAP ALL HORZ BARS 2411 MIN @ SPLICE LOCATIONS. PROVIDE (2)-#5 CONT HORZ BARS @ THE TOP OF THE WALL. EXTEND ALL VERT REINF 1111 MIN INTO THE LID CLOSURE POUR. 203. #5 FTG TO WALL DOWEL @ EA VERT. PROVIDE STD HOOK @ END OF BAR CAST INTO FOOTING. DOWELS SHALL BE EMBEDDED A MIN. OF 9" -/- 11211 INTO THE FTG & SHALL EXTEND INTO THE WALL 2811 MIN. SEE 6/54 FOR PLACEMENT DETAIL. 204. #5x4'-011@24"o/c PLACED SUCH THAT EACH 4811 WIDE PLANK RECEIVES (2) BARS, LOCATE BARS IN VOIDS WITH POUR SLOTS AS SHOWN ON THE PRECAST PLANK PLACEMENT DWGS, PROVIDE ADDITIONAL BARS @ EACH PLANK IF REQ'D AND SHOWN ON THE PRECAST PLANK SHOP DWGS. 205, LID & WALL TO CLOSURE POUR REINF @ VOID BLOCK OUT. SEE 8/S4 206, LID & WALL TO CLOSURE POUR REINF @ VOID END FILL, SEE 7/S4. 207. OHS CONT IN CLOSURE POUR. LAP 36" AT ALL SPLICE LOCATIONS. 208. (2)-#5 CONT. 209. REINF FTG w/ #5@18"o/c TRANS & (2)45 LONG BOTTOM. 210. REINF FTG w/ #5@12"o/c TRANS & (3)45 LONG BOTTOM, 211. PROVIDE (2)-#5 VERT EACH FREE EDGE OF WALL. 212. ADD (4)-#5x8'-O" TOP WITHIN THE FOOTING CENTERED BELOW THE OPENING. 213. #5 @1211o/c HORZ. 214. (2)-#7x10'-011@3"o/c. EXTEND 3011 BEYOND EACH JAMB. 215. #4 VERT w/ 180 HOOK @ HEAD OF OPNG, SPACED AS SHOWN. 216. 12)-#5 x 4'-011 DIAGONAL BARS. 217. (2)45 HORZ @ THE TOP OF THE WALL. 218, #4@12"olc WALL TO FOOTING DOWELS. EXTEND 4811 INTO THE WALL AND 9" INTO THE 12" THICK FOOTING, PROVIDE 23" HOOK AT END OF BAR EMBEDED WITHIN FTG. PROVIDE 12)-#4 CONT HORZ. BARS WITHIN THE WALL AS SHOWN, SET DOWELS 1-1/2" CLR FROM THE BACKFILLED FACE OF THE WALL. 219, #5 LONG AS SHOWN. LAP 2411 AT ALL SPLICE LOCATIONS. 220, #4 FTG TO WALL DOWEL @ EA VERT. PROVIDE STD HOOK @ END OF BAR CAST INTO FOOTING. DOWELS SHALL BE EMBEDDED A MIN. OF 911 -/- 1/211 INTO THE FTG & SHALL EXTEND INTO THE WALL 28" MIN. SEE 6/S4 FOR PLACEMENT DETAIL. REVV . l dED r OR CODE C ;,'-o_!;,NCE DEC b City of l , , !,q BUILDING \/ Z�N VAULT WALL$ll 1T VERT REINF VAULT WALL - %00REVOLEW&VIllDt ELEVATION VIEW CLOSURENG INTO ELEVATION VIEW NOV.! 4 2Q95 LID & WALL TO CLOSURE DOWELS LID & WALL TO CLOSURE DOWELS � AT PLANK END VOID FILL - 8" WALL � AT PLANK EDGE VOID BLOCKOUTS - 8" WALL RE10 r1fiIDOLETON. tivc., S4 SCALE 3/4"=1' d" 64 SCALE 3/4114-0" o� a � a � W = c v ~ v a U � 4 C a O �- W O y 0 N o LL n U W W LL W = c o W W y y y ¢ m s o 0 0 0 0 aU m z c m o W 3, am m w z 0 no O w J O H Lu H W 93 W 'c O N O W J 4 O z fA R U. O I SHEET: I