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Permit L09-030 - CABUDOL FLORENDO / CITY OF SEATAC - SPECIAL PERMISSION WETLAND BUFFER
CITY OF SEATAC Special Permission Wetland Buffer Storm Water Improvements L09 -030 • City of Tukwila lYV i/l a Jim Haggerton, Mayor Jack Pace, Director Department of Community Development NOTICE OF DECISION TO: City of SeaTac, Applicant Washington State Department of Transportation (WSDOT), Owner King County Assessor, Accounting Division Washington State Department of Ecology July 6, 2009 This letter serves as a notice of decision and is issued pursuant to TMC 18.104.170 on the following project and permit approval. I. PROJECT INFORMATION Project File Number: L09 -030 Applicant: City of SeaTac Type of Permit Applied for: Special Permission from the Director for work within a Wetland Buffer Project Description: The City of SeaTac is working on stormwater improvements in the Sunrise View neighborhood. As part of these improvements, the City of SeaTac will install a 36 inch stormwater line within 53rd Ave South which will discharge into the right -of -way (ROW) of Interstate 5. Within the ROW of Interstate 5 the City of SeaTac will install an outfall which will include the use of gravel as an energy dispensator. The outfall and gravel will be installed within the buffer of a Type III wetland which is located to the east of the project site, within the ROW of Interstate 5. The City of SeaTac has submitted a Special Permission application to the City of Tukwila requesting to disturb 425 square feet of a Type III wetland (See Attachment A: Letter from Applicant). As mitigation the applicant has proposed to enhance 488 square feet of the wetland's buffer. Location: Within WSDOT Right of Way, adjacent to Valley View Sewer Pump Station at S 170th Street and 53md Ave S Associated Files: None Comprehensive Plan Low Density Residential (LDR) Designation/Zoning District: B. Miles Page 1 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \NOD Type 2 permit.doc 6300 Southcenter Boulevard, Suite #100 0 Tukwila, Washington 98188 o Phone: 206 - 431 -3670 0 Fax: 206 - 431 -3665 II. DECISION SEPA Determination: The City of SeaTac issued a Mitigated Determination of Non - Significance (MDNS) on April 13, 2009. The City of Tukwila has not issued any SEPA Determinations for the proposed project. Decision on Substantive Permit: The Community Development Director has determined that the application for Special Permission by the Director for work within a wetland buffer does comply with applicable City and state code requirements and has approved that application, subject to the following conditions: 1. Prior to any grading occurring within the wetland buffer area the applicant shall install a temporary erosion control fence around the edge of the buffer area that will not be impacted during construction. This temporary erosion fence shall be removed upon completion of the project. All trees that are to be retained on site shall be clearly marked in the field as being retained. 2. No construction debris, garbage or any other materials shall be placed within the buffer areas. 3. The applicant shall plant an additional two douglas firs within the planting area. 4. Removal of vegetation within the enhanced buffer as shown in attachment "D" area shall be done by hand and the use of heavy machinery is strictly forbidden. 5. The applicant shall install three signs denoting the presence of the wetland buffer. See attachment "D" for signs locations. The signs shall be constructed of plastic or treated wood and shall be at least two feet by two feet in size. 6. Prior to calling for a final inspection of the enhancement buffer area, the applicant shall submit a "Certification of Planting" to the City of Tukwila. The Certification shall note that the planting has been completed per the approved enhancement plan. The City shall not conduct any finals until this certification has been provided to the City. 7. No modification to the enhancement plan or the plantings shown on the enhancement plan shall occur without the prior approval of the City of Tukwila Department of Community Development. The City's findings and conclusions on contained in the staff report dated June 29, 2009 III. YOUR APPEAL RIGHTS The Decision on this Permit Application is a Type 2 decision pursuant to Tukwila Municipal Code §18.104.010. Other land use applications related to this project may still be pending. One administrative appeal to the Planning Commission of the Decision on the Permit itself is permitted. A party who is not satisfied with the outcome of the administrative appeal process may file an appeal in King County Superior Court from the Planning Commission decision. IV. PROCEDURES AND TIME FOR APPEALING In order to appeal the Community Development Director's decision on the Permit Application, a written notice of appeal must be filed with the Department of Community Development within 21 days of the issuance of this Decision, that is by July 27, 2009. B. Miles Page 2 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \NOD Type 2 permit.doc • • The requirements for such appeals are set forth in Tukwila Municipal Code 18.116. All appeal materials shall be submitted to the Department of Community Development. Appeal materials MUST include: 1. The name of the appealing party. 2. The address and phone number of the appealing party; and if the appealing party is a corporation, association or other group, the address and phone number of a contact person authorized to receive notices on the appealing party's behalf. 3. A statement identifying the decision being appealed and the alleged errors in the decision, including any specific challenge to an MDNS. 4. The Notice of Appeal shall identify (a) the specific errors of fact or errors in application of the law in the decision being appealed; (b) the harm suffered or anticipated by the appellant, and (c) the relief sought. The scope of an appeal shall be limited to matters or issues raised in the Notice of Appeal. 5. Appeal fee based on current fee schedule. V. APPEAL HEARINGS PROCESS Any administrative appeal regarding the Permit shall be conducted as an open record hearing before the Planning Commission based on the testimony and documentary evidence presented at the open record hearing. The Planning Commission decision on the appeal is the City's final decision. Any party wishing to challenge the Planning Commission decision on this application must file an appeal pursuant to the procedures and time limitations set forth in RCW 36.70C. An appeal challenging a DNS, an MDNS or an EIS may be included in such an appeal. If no appeal of the Planning Commission decision is properly filed in Superior Court within such time limit, the Decision on this permit will be final. VI. INSPECTION OF INFORMATION ON THE APPLICATION Project materials including the application, any staff reports, and other studies related to the permits are available for inspection at the Tukwila Department of Community Development, 6300 Southcenter Blvd., Suite 100, Tukwila, Washington 98188 from Monday through Friday between 8:30 a.m. and 5:00 p.m. The project planner is Brandon J. Miles who may be contacted at 206 - 431 -3684 for further information. Property owners affected by this decision may request a change in valuation for their property tax purposes. Contact the King County Assessor's Office for further information regarding property tax valuation changes. The notice board must be removed at the expiration of the appeal period if no appeal is filed. eve Jack ce, Director Dep ent of Community Development City of Tukwila B. Miles Page 3 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \NOD Type 2 permit.doc MEMORANDUM June 29, 2009 TO: Jack Pace, Director, Department of Community Development FM: Brandon Miles, Senior Planner RE: L09 -030, Special Permission, Director, Request to work within the buffer of a Type III wetland buffer pursuant to TMC 18.45.070 (B). The City of SeaTac is working on stormwater improvements in the Sunrise View neighborhood. As part of these improvements, the City of SeaTac will install a 36 inch stormwater line within 53r Ave South which will discharge into the right -of -way (ROW) of Interstate 5. Within the ROW of Interstate 5 the City of SeaTac will install an outfall which will include the use of gravel as an energy dispensator. The outfall and gravel will be installed within the buffer of a Type III wetland which is located to the east of the project site, within the ROW of Interstate 5. The City of SeaTac has submitted a Special Permission application to the City of Tukwila requesting to disturb 425 square feet of a Type III wetland (See Attachment A: Letter from Applicant). As mitigation the applicant has proposed to enhance 488 square feet of the wetland's buffer. Background The wetland site is located within the ROW of Interstate 5 and thus Washington State Department of Transportation (WSDOT) has control of the project area. Shannon and Wilson, Inc prepared a Wetland and Stream Reconnaissance Report dated June 19, 2008 for the entire project (See Attachment B). The report identified the impacted wetland as "Wetland D" and noted the following characteristics regarding the project site: "Wetland D is palustrine, emergent, seasonally-flooded/saturated wetland under the Cowardin classification system and riverine wetland under the HGM classification system. Wetland D appears to be largely supported by stormwater that flows beneath the [existing] pump station and discharges into Stream 4, between the pump station and 1 -5. Vegetation within Wetland D is dominated by Reed Canary grass; Yellow Flag Iris; Broadleaf Cattail; and Red Alder ". The report has concluded that the wetland would be classified as a Type III wetland under the City of Tukwila's regulations. According to TMC 18.45.080 a Type III wetland is a wetland that is greater than 1000 square feet and less than one acre in size with two or fewer wetland classes. TMC 18.45.080 (E)(3) requires a 50 foot buffer for all Type III wetlands. The wetland is B. Miles Page 1 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \Stream SR.doc associated with a nearby Type IV stream. No impacts to the stream or the stream's buffer are anticipated from this project. The applicant's report does not provide information on how the subject wetland was formed. Most likely the wetland was formed as result of the construction of Interstate 5 which has prevented water from moving to the east and thus an artificial wetland area was created. However, while it is likely that the wetland is man made it is still regulated by the City. TMC 18.45.070 outlines permitted uses allowed with sensitive areas and their buffers. Construction of new essential utilities is permitted with approval of the Director. As noted, the applicant is constructing a new stormwater outfall and thus would qualify as an essential utility. Applicable Review Criteria TMC 18.45.070 (B)(3) provides that following criteria for stormwater discharge into sensitive areas and their buffers: New water discharges to sensitive area or their buffers from detention facilities, pre- settlement ponds or other surface water management structures may be allowed provided that the discharge meets the clean water standards of RCW 90.48 and WAC 173.200 and 173.201 as amended, and does not adversely affect water level fluctuations in the wetland or adversely affect watercourse habitat and watercourse flow conditions relative to the existing rate. The City of SeaTac, like the City of Tukwila, operates under a Nationwide Permit for the discharge of stromwater. The Nationwide Permit assures compliance with the Clean Water Act. Issuance and compliance of the nationwide permits is done by the Washington State Department Ecology. The applicant has noted that the water discharged into the wetland buffer will comply with the standards of RCW 90.48, WAC 173.200, and WAC 173.201. Additionally, the project will match existing flow rates and will not adversely affect water levels (See Attachment C, Email from applicant dated June 30, 2009). TMC 18.45.070 specifies the following criteria for the placement essential utilities within sensitive areas and their buffers: A. Essential utilities must be constructed to minimize, or where possible avoid, disturbance of the sensitive area and its buffer. The applicant is retrofitting an existing outfall for a regional storm water system that serves the City of SeaTac. Storwmater lines and outfalls utilize gravity to convey stormwater discharge. Outfalls are often located near wetlands, streams, and /or their associated buffers given the interconnection between strom water run off and wetlands /streams, thus avoidance of the impact is not possible. The impact to the buffer area will be minimal and will include some excavation and installation of quarry spalls. The quarry spalls are needed as an energy dispensator given the velocity of the water at the outfall. Without the quarry spalls the water would gradually B. Miles Page 2 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \Stream SR.doc • • erode the area around the outfall. The sediment from this erosion could eventually enter the Type III wetland or the adjacent Type IV stream. The disturbed area is the minimal necessary to accomplish the installation of the stormwater outfall. B. All construction must be designed to protect the sensitive area and its buffer against erosion, uncontrolled storm water, restriction of groundwater movement, slides, pollution, habitat disturbance, any loss of flood carrying capacity and storage capacity, and excavation or fall detrimental to the environment. As noted the applicant is replacing an existing outfall with a new facility. The area that will be disturbed is 425 square feet and the applicant will install quarry spalls to prevent erosion around the outfall opening. The grade of the disturbed area will match the grade of the adjacent wetland. This would ensure that existing water movements in the area are maintained. Existing vegetation within the construction area will be removed. As mitigation the applicant will enhance the 488 square feet of the adjacent wetland buffer area (See Attachment D: Conceptual Landscaping Plan). As noted, existing flows will be maintained and the project will comply with the applicable water quality standards. C. Upon completion of installation of essential utilities, sensitive areas and their buffers must be restored to pre project configuration, replanted as required and provided with maintenance care until newly planted vegetation is established. This criterion assumes that the disturbance to a sensitive area or its buffer will be limited to above or below ground facilities where it would be possible to replace after completion of the project. However, this project will require the permanent placement of an outfall within a wetland buffer. The project will require the permanent disruption of 425 square feet of wetland buffer. To mitigate the impact to the wetland buffer the applicant has proposed enhancing 488 square feet of additional area within the wetland's buffer. The applicant's enhancement plan calls for the removal of invasive vegetation, planting of Snowberries, and Sitka Williows. The applicant's plan does not include the plantings of any evergreen trees. The City's Urban Environmentalist has concluded that adding several evergreen trees would provide species variety within the enhancement area. A condition has been added to address the City's concern. The applicant has noted that they will maintain the enhancement area until the new plants are established. The applicant will also need to maintain the outfall and these maintenance activities could impact the remaining buffer area if the buffer area is not clearly marked. The applicant has proposed no signs or other control features to identify the wetland buffer area. A condition has been placed to require installation of several signs around the buffer area. D. All crossings must be designed as shared facilities in order to minimize adverse impacts and reduce the number of crossings. B. Miles Page 3 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \Stream SR.doc The above criterion is not applicable. The area where the outfall will be located will not be used for other utilities. Additionally, the applicant is not crossing the wetland buffer or the wetland, but is instead installing a stormwater outfall. RECOMMENDATION Staff recommends approval of the proposed Special Permission application with the following conditions: 1. Prior to any grading occurring within the wetland buffer area the applicant shall install a temporary erosion control fence around the edge of the buffer area that will not be impacted during construction. This temporary erosion fence shall be removed upon completion of the project. All trees that are to be retained on site shall be clearly marked in the field as being retained. 2. No construction debris, garbage or any other materials shall be placed within the buffer areas. 3. The applicant shall plant an additional two douglas firs within the planting area. 4. Removal of vegetation within the enhanced buffer as shown in attachment "D" area shall be done by hand and the use of heavy machinery is strictly forbidden. 5. The applicant shall install three signs denoting the presence of the wetland buffer. See attachment "D" for signs locations. The signs shall be constructed of plastic or treated wood and shall be at least two feet by two feet in size. 6. Prior to calling for a final inspection of the enhancement buffer area, the applicant shall submit a "Certification of Planting" to the City of Tukwila. The Certification shall note that the planting has been completed per the approved enhancement plan. The City shall not conduct any finals until this certification has been provided to the City. 7. No modification to the enhancement plan or the plantings shown on the enhancement plan shall occur without the prior approval of the City of Tukwila Department of Community Development. Attachments: A. Letter from applicant dated June 23, 2009 B. Wetland and Stream Reconnaissance Report, Sunrise View Stormwater Bypass, Alternatives, SeaTac, Washington; prepared by Shannon and Wilson, Inc dated June 19, 2009. C. Email from applicant dated June 30, 2009. D. Conceptual Enhancement Plan dated stamped received by the City on June 23, 2009. B. Miles Page 4 07/01/2009 H: \Special Permission \SeaTac, L09- 030 \Stream SR.doc Page 1 of 2 Brandon Miles - RE: Sunrise Project From: "Florendo Cabudol" To: "Brandon Miles" Date: 06/30/2009 10:36 AM Subject: RE: Sunrise Project Brandon, This project will comply with the clean water standards of RCW 90.48 and WAC 173.200 and 173.201 as amended. The project is matching existing flow rates and will not adversely affect water level fluctuations in the wetland or adversely affect watercourse habitat and watercourse flow conditions. There are three sizes of rock proposed for the outfall, maximum stone size = 24- inches (nominal diameter); median stone size = 16- inches; minimum stone size = 4- inches. Please let me know if there are any further questions. Thanks, Florendo Cabudol, P.E. Civil Engineer 2 City of SeaTac Public Works, Eng. Div. 4800 S 188th St SeaTac, WA 98188 -8605 P: 206.973,4740 F: 206.973.4809 From: Brandon Miles [mailto:bmiles @ci.tukwila.wa.us] Sent: Tuesday, June 30, 2009 10:18 AM To: Florendo Cabudol Subject: Sunrise Project Hi Florendo- Some more question, the proposed stormwater outfall will maintain (no increase or decrease) the existing rate of flow at this location? The reason I ask is we have the following requirement for a stormwater outfall within SAO: New water discharges to sensitive area or their buffers from detention facilities, pre - settlement ponds or other surface water management structures may be allowed provided that the discharge meets the clean water standards of RCW 90.48 and WAC 173.200 and 173.201 as amended, and does not adversely affect water level fluctuations in the wetland or adversely affect watercourse habitat and watercourse flow conditions relative to the existing rate. Can you also state if the water discharged will comply with the cites listed above. I assume it will given that file : / /C:\temp\XPgrpwise\4A49EAC2tuk-mail6300-p� 100130796C113F851 \GW} 00001.... 06/30/2009 Page 2 of 2 SeaTac is operating under a NPDES permit for its stormwater discharge. Thanks, Brandon Brandon J. Miles Senior Planner Department of Community Development City of Tukwila tel (206) 431 -3684 fax (206) 431 -3665 bmiles @ci.tukwila.wa.us file: / /C:\ temp\ XPgrpwise \4A49EAC2tuk- mai16300 -po 100130796C 113F851 \GW } 00001.... 06/30/2009 ECOLOGY BLOCK WAL £1. FLATTEN CHANNEL SIDE SLOPES TO MATCH WETLAN EDGE HERE. DO NOT DISTUI WETLAND/ / IE ‘18”CPVP=2:20.84 IE 6"PVC /CAPP'LED-=221.2( -5 , 36" qyPE 45' BEND, pi OR FLANGED IE 21.80 SS M =1226.1 9 cl 'CHM; (11S4)-21( kicroal. 'Or-r-ge-medtioefsF 2'1 9.89 EXTEND EXIST = 11 9.89 AND DC CHANNEL WALL 87c. W. .11 9 Ci Q COITAUNiTY DEEVELONIENT 8' DIA. WET (CUT OFF AM --gipLibiC. ;Iq' EASEMENT LAST BL'OOk(S) 14" C. 3-61ALDER NEEDED TO INSTALL PIPE 1j) ; \ NORTH: OUTFALL — PARTIAL PLAN filioP°9tD wcglu.-"=1 SCALE: 1"=10.-0" C2.03 5uPPece- 6,00c6clareW 4800 South 188' Street SeaTac, WA 913188 -8605 City Hall: 206.973.4800 Fax: 206.973.4809 TDD: 206.973.4808 Mayor Ralph Shape Deputy Mayor Gene Fisher Councilmembers Chris Wyihe Terry Anderson Tony Anderson Beny Ladenburg Mie Gregerson City Manager Craig Ward Assistant City Manager Todd Culls City Attorney Mary Mirante Bartolo City Clerk Kristine Gregg DEPARTMENT OF PLANNING AND COMMUNITY DEVELOPMENT April 10, 2009 Mr. Florendo Cabudol City of SeaTac Public Works Dept. 4800 S. 188th Street SeaTac, WA 98188 -8605 SUBJECT Dear Florendo: MITIGATED DETERMINATION OF NONSIGNIFICANCE SUNRISE VIEW BYPASS PIPELINE FILE NO. SEP09 -00004 Enclosed are the "Mitigated Determination of Nonsignificance " (MDNS), and vicinity map regarding the Public Works Department proposal to construct stormwater infrastructure, which is inadequately sized or nonexistent in the Sunrise View neighborhood, located within the Right -of -Way of 51 "' Avenue South and 53"I Avenue South, SeaTac, Washington. You will find enclosed 20 two -sided copies of the MDNS for the pocket on the notice board and an "Affidavit of Removal" to be signed, notarized, and returned to the Planning Department at the end of the appeal period, (May 7, 2009). Please replace the NOA notices with the enclosed MDNS notices, change the Comment Deadline to April 27, 2009 and add the Appeal Deadline, May 7, 2009, to the "Notice Board" no later than April 13, 2009. If you have any questions concerning the above, please contact Sandy Neilson or me at 206- 973 -4830. Sincerely, Al Torrico Senior Planner cc: Stephen Butler, Director of Planning and Community Development Jack Dodge, Principal Planner Dixie Hallenberger, Engineering Technician Supervisor Robert W. Meyer, Fire Chief Attachment: "Mitigated Determination of Nonisignificance" Notices (20) "Affidavit of Removal" MITIGATED DETERMINATION OF NONSIGNIFICANCE FILE(S) SEP09 -00004 DESCRIPTION OF PROPOSAL: The project proposes the construction of a stormwater conveyance pipe in a residential area where no or inadequate piping currently exists in order to relieve neighborhood flooding.caused by upstream development and undersized private stormwater infrastructure in the project area. PROPONENT: City of SeaTac 4800 South 188`' St. SeaTac, WA 98118 -8605 CONTACT: Engineering Department Florendo Cabudol, P.E. TELEPHONE: (206) 973 -4740 4800 South 188th St. SeaTac, WA 98188 -8605 LOCATION OF PROPOSAL: SW '/, of Sec. 26, Township 23 North, Range 4 East, WM; in the Sunrise View neighborhood. It includes segments within the right of way of 51st Ave. South and 53rd Ave. South. The segment on 51st Ave. South extends between just north and just south of South 170th Lane. LEAD AGENCY: City of SeaTac The responsible official of the City of SeaTac hereby makes the following determination based upon impacts identified in the environmental checklist and the Final Staff Evaluation for the Environmental Checklist (Case No. SEP09- 00004); and, Conclusions of Law based upon the City of SeaTac. Comprehensive Plan and other Municipal policies, plans, rules and regulations designated as a basis for the exercise of substantive authority of the Washington State Environmental Policy Act Rules pursuant to R.C.W. 43.21C.060. The lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment, and an environmental impact statement (EIS) is not required under RCW 43.21 C.030(2)(c), if certain conditions are met. This decision was made after review of a completed environmental checklist and other information on file with the lead agency. The City reserves the right to review any new information; future revisions or alterations to the site or the proposal (WAC 197 -11 -340) in order to determine the environmental significance or non-Significance of the project at that point of time. Detailed information and copies of the conditions are available to the public on request: CONTACT: Albert Torrico, Jr., Senior Planner, at 206- 973 -4830. E -mail address: atorrico @ci.seatac.iva.us COMMENT PERIOD: This MDNS is issued under WAC 197 -11- 340(2); the lead agency will not act on this proposal for 14 days from the date of issuance. Comments must be submitted by 5:00 P.M., on Monday. April 27, 2009. APPEAL PERIOD: Any person wishing to appeal this determination may file such an appeal within ten (10) days of the end of the comment period (April 27, 2009) to the SeaTac City Clerk. All appeals of the above determination must be filed by 5:00 P.M., May 7, 2009. THERE IS A $100.00 FEE TO APPEAL THIS DETERMINATION. RESPONSIBLE OFFICIAL: Jack Dodge Acting Director of Planning and Community Development 4800 South 188th Street SeaTac, Washington 98188 =8605 (206) 973- 4830/1'DD 973 -4808 DATE ISSUED/PUBLISHED IN THE SEATTLE TIMES: APRIL 13, 2009 RECEWED 6 � ; ..d , ti s Cd iF.� r_ 1-1 25' L. COMMUNITY DEVELOPMENT 4-.•?a,stas.,4ztr.t4c::•.‘.: ( 7,‘Irr. • -..VITi T-itg:15110g11-.Fig;;;Iii *\.,If:•34.4C,-,-.7,,:ir7C4•E:,. .. '-':::::•:',:;.V.1 k.7.!;;`'..;- Date Prepared: Feb 19, 2009 City of SeaTac Sunrise View Bypass Pipeline SEPO9-00004 (Vicinity Map) E 518 to- SOUTHCENTER BLVD En w cn w 1-- > w co < — to k1-1 0 -7 ti,,_ .- q". '... 1122. 'F/). co — .. TUKWILA-PKWY .... co- -. -- -----.. - - - ----. --- S 151ST ST /4, o-+ cr q/I, TI\ C/) ---:SeaTacacity,. ..S 16 - 0TH ST o /? w > 0 - 1"--- . • . - 0 ... co it < a 170TH ST S. 1.64TH ST • i< II1- T9 >- ... 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AAIIA% MAI RA It 110.0•.10 loll 1.014 MAN 1(1(11 DA,l OV1St 0[ Dar AVM 071 IRO can PURIM 110 III 100(011 01111 3ra... COW 11011 CROP. unr'OSI. ?411111 110[010 CR t0111vll' ti cf,:gi79TPt10 ._9 9L 1cE (PACE .�; '01010_ uoll lu¢ iD5611. xxx Icon. xxx I f f ' , . . ; ; • r - i Irji •.I 1_ 1`. 1,j; ••. ��; .1 •I • Public 4Torlcs Dt-pnrtmenl. /an, 1,.•t, P,E,. Pobric weeds [Mantra Susan Sanderson. 1,.L. fin Enabler, • n R•MI s..1.c•... nnYOeet [(1•0001 •11011 010.1111. (1001•• -t a+'w ;111;1. Il. 77!1: Ib�•`s, 1r� It. [(11(1111 It soros Pal 01101 foil LaAM.nllnt 511111 000. IS St(0 nn 111 Ant A1(A% In Anion 00.0410 001 PORt 111111 in 11015 11. UPM COU^1Sna1 a '10(101,1. 101 01)1101010 AR1A9 In01 A SI101RO l•m O6r puMOLIMr ISIACR01 (1[0(1100 .1 ArrnOPlultL Call before you Djg. 1 -000- 424.6585 SEPA SUBMITTAL CI'T'Y OF SNA'I'A(.: SUUMC? 1101 SUNRISE VIEW IIYI'ASS I'Ii`r•;i.INR C :1..01 TEMP. EROSION R SEAM N'I' CUhI'I'RUI. PLAN ;El! Na 171(1 511. OM1Z- f.A1F.: 1_,•dii Or x CITY OF SEATAC AFFIDAVIT OF "NOTICE BOARD" REMOVAL File No: SCPd 5 OJcJJLf STATE OF WASHINGTON ) ss. COUNTY OF KING I acknowledge that the Notice Board must be removed within fourteen days after the expiration of the appeal period outlined in the "Notice of Application ", "Mitigated Determination of Non - significance ", or the "Notice of Decision" issued by the City. I, , being first duly sworn upon oath, depose and say: That I am the property owner or authorized representative of the property owner /s, and I have removed the Notice Board. Property Owner /Authorized Representative SUBSCRIBED AND SWORN TO before me on NOTARY PUBLIC in and for State of Washington My Commission Expires: O.OMEVkJN TT( OEVELORt rEf4T MITIGATED DETERMENATION OF NONSIGNIFICANCE FILE(S) SEPO9- 00004 DESCRIPTION OF PROPOSAL: The project proposes the construction of a stormwater conveyance . pipe in a residential area where no or inadequate piping currently exists. The conveyance pipe will relieve neighborhood flooding caused by upstream development and undersized private stormwater infrastructure in the project area. PROPONENT: City, of SeaTac . 4800 South 188th St. SeaTac, WA 98118 -8605 CONTACT: Engineering Department Florendo Cabudol, P.E. TELEPHONE; (206) 973 -4740 4800 South 188th St. SeaTac, WA 98188 -8605 LOCATION OF PROPOSAL: SW % of Sec. 26, Township 23 North, Range 4 East, WM, in the Sunrise View neighborhood. It includes segments within the right of way of 51st Ave. South.and 53rd Ave. South. The segment on 51st Ave. South extends between just north and just south of South 170th Lane. LEAD AGENCY: City of SeaTac The responsible. official of the City of SeaTac hereby makes the following determination based upon impacts identified in the environmental checklist and the Final "Staff Evaluation for Environmental Checklist (Case No SEP09- 00004), and Conclusions of Law, based , upon the City of SeaTac Comprehensive Plan, and other Municipal policies, plans, rules and regulations designated as a basis for the exercise of substantive authority of the Washington State' Environmental Policy Act Rules pursuant to R.C.W. 43.21C.060. FINDINGS OF FACT 1. The removal/ import /stockpile of soil and removal of debris could result in mud, dust, and .erosion/sedimentation leaving the site Preparation and implementation of a Temporary Erosion Sediment Control (TESC) plan will limit erosion leaving the site during - grading and construction activities. Measures to mitigate potential erosion problems include, but are not;: limited to, dewatering, silt fencing, soil stabilization, covering stockpiled soils, timely restoration of disturbed areas, inlet protection, and street sweeping. C,EMr It is anticipated that approximately twelve (12) cubic yards of existing soil will be removed and replaced with rock. 3. Construction activities will result in localized increases in pollutant, emissions from construction equipment Implementation of reasonable precautions to minimize dust emissions will be used. These measures may include, but are not limited to, applying water during dry periods to suppress dust and other air borne particulates, a vehicle wheel wash and street cleaners to keep mud and debris off public roadways. Once the project has been completed, the main sources of emissions will be from vehicles coming to and from the project area. These will be consistent with current emission levels. 4. Construction activities could lead to short-term disturbance of stream flow, wetland, wetland buffers and water quality. Clearing, grading, trenching and backfilling may result in soil movement at the site which could lead to soil erosion and diminished water quality. Concrete work could result in cement entering the water channels. Surface water and ground water may need to be diverted/bypassed around areas of active construction. Implementation of a Temporary Erosion Sediment Control (TESC) plan will limit erosion leaving the project site during construction activities. Regular inspections by the City of SeaTac Public Works Department will also help monitor for potential erosion impacts and advise the contractor on corrective measures: 5. The following measures will be implemented so as to limit potential impacts to sensitive areas: a. Construction work is scheduled to occur during dry weather months (July to September) so as to reduce potential for erosion and sediment runoff; b. All excavation is located outside of identified wetlands and streams; c. Source Control Best Management Practices (BMPs) will be implemented and includes the installation of silt fencing and catch basin filters to prevent sediment laden runoff from mixing with clean runoff; d. Any disturbed areas, arising as a result of construction activities, will be stabilized and protected against erosion at the end of each work day with vegetated areas restored at the completion 'of construction activity ; - ' e. Additionally, other BMPs will be implemented including the installation of gabion energy dissipaters at the natural discharge locations to disperse runoff and the installation of Flow Restrictive /Oil Pollution (FROP) -Tee fittings at the catch basin outlets to serve as an oil /water separator and to provide water quality treatment; and f. Routine maintenance of City stormwater facility structures. 6. A number of pipeline alignments were considered during the planning of this project. Following a careful review of the environmental risks and disadvantages of these options, the proponent determined that the proposed project design would considerably minimize any impacts to the environment and adjoining neighborhood. 7. Approximately 7,200 square feet of vegetation will be removed, including grasses, small trees and blackberry bushes. 8. Use of construction equipment and powered- tools may result in short-term noise generation and dust during clearing, grading and construction activities. Implementation of standard Best Management Practices will limit and control such emissions. 9. The "FINAL STAFF EVALUATION FOR ENVIRONMENTAL CHECKLIST FILE NO. SEP09- 00004 ", prepared April 2009, is hereby incorporated as stated in full as an analysis of the Environmental Checklist. CONCLUSIONS OF LAW The following polices are SEPA policies that apply to the proposed project; Policy 8.2A — Design land. use development to prevent property damage and environmental degradation, and enhance greenbelt and wildlife habitat values. Policy 8.2D _ Retain or replace native ground cover in development areas subject to erosion hazards. Use special construction practices to reduce site coverage of development to prevent erosion and sedimentation. Consider time limitations on construction work to reduce erosion and sedimentation. Policy 8.2H — Maintain and enhance natural drainage systems to protect water quality, reduce public costs and prevent environmental degradation. Do not alter natural drainage systems without acceptable mitigation measures which eliminate the risk of flooding or negative impacts to water quality. Policy 8.2I — Protect water quality and natural drainage systems by controlling the quality and quantity of stormwater runoff. Policy 8.2K Design site plans and construction practices to minimize on -site erosion and sedimentation during and after construction. Policy 8.2Y — Consider the impacts of new development on air quality as a part of the environmental review process and require any appropriate mitigating measures.' Policy, 8.1B -. Manage water resources for multiple uses, including recreation, fish and wildlife, flood protection, erosion control, water supply, energy production, and open space. Policy 8.1C — Work with adjacent jurisdictions and other affected entities to enhance and protect water quality in the region: Policy 8.1D — Preserve water quality of natural surface water storage sites that help regulate stream flows and recharge groundwater. Policy 8.1E. - Protect water quality, natural drainage, fish and "wildlife habitat; and aesthetic functions of streams, creeks, and lakes. Policy 8.1F — Preserve an undisturbed corridor wide enough to maintain natural functions between new development and streams, creeks and lakes. When impacts from new development are unavoidable, ensure that those impacts result in stream and creek corridors that are wide enough to maintain natural functions between the new development and streams, creeks, and lakes. Policy 8.2D — Retain or replace native ground cover in development areas subject to erosion hazards. Use special construction practices to reduce site coverage of development to prevent erosion and sedimentation. Consider time limitations on construction work to reduce erosion and sedimentation. Policy 8.2I — Protect water quality and natural drainage systems by controlling the quality and quantity of storm water runoff. Policy 8.2J — Do not increase peak storm water runoff from new development. Do not increase total runoff quantity from new development in critical drainage, erosion, or flood hazards. Policy 8.2K — Design site plans and construction practices to minimize on -site erosion and sedimentation during and after construction. CONDITIONS 1. If necessary, all State and Federal permits shall be obtained prior to the commencement of construction activities. 2. The hours of grading or construction activity shall be from 7:30 a.m. to 8:00 p.m., weekdays only, unless otherwise approved by the Director of Planning and Community Development and the Public Works Director. DETERMINATION The lead agency for this proposal has determined that it does. not have ,a probable significant adverse impact on the environment, and an environmental impact statement (EIS) is not required under RCW 43.21 C,030(2)(c), only if certain conditions are met. This decision was made after review of a completed environmental checklist and other: information. on file with the lead agency. The City reserves the right to review any new information, future revisions ..or alterations to the site or. the proposal (WAC 197 -11 -340) in,order i er to determine the: environmental significance or non - significance of the project at that point of time. Detailed. information and of the determination are available to the public on request. ' CONTACT :. Albert Torrico, Jr., Senior Planner, at 206 -973- 4830. E -mail address: atorrico @ci.seatac.wa.us COMMENT PERIOD: This MDNS is issued under WAC 197 -11- 340(2); the lead agency will not act on this proposal for 14 days, from the date of issuance.. Comments must be submitted by 5:00 P.M.'on Monday. April 27, 2009. APPEAL. PERIOD: Any person wishing to appeal this determination may file such an appeal within ten (10) days of the end of the comment period (Monday, April 27, 2009) to the SeaTac City Clerk. All appeals of the above determination must be filed by 5:.00.P.M. on May 7, 2009. THERE IS A $100.00 FEE TO APPEAL THIS DETERMINATION. RESPONSIBLE OFFICIAL: Jack Dodge Acting Director of Planning & Community Development 4800 South 188th Street SeaTac, Washington 98188-8605 (206) 973-4830/TDD 973 -4808 g `ck Dodge, Acting Dire for Date: DATE ISSUED /PUBLISHED IN THE SEATTLE TIMES: APRIL 13, 2009 7-n �.r0\ Ge C a�3 CITY OF SEATAC FINAL STAFF EVALUATION FOR ENVIRONMENTAL CHECKLIST FILE NO: SEP09 -00004 APPLICANT: City of SeaTac 4800 South 188th St. SeaTac, WA 98118 -8605 CONTACT: Engineering Department Florendo: Cabudol, P.E. 4800 South 188th St. SeaTac, WA .98188 -$605 TELEPHONE: (206) 973 -4740 LOCATION: SW % of Sec. 26, Township 23 North, Range 4 East, WM, in the Sunrise View neighborhood. It includes segments within the right of, way of 51st Ave. South and 53rd Ave. South. The segment on 51st Ave. South extends between just north and just south of South 170th Lane. PROPOSAL: The project proposes the construction of a , stormwater conveyance pipe in a residential area where no or inadequate piping currently exists. The conveyance pipe will relieve neighborhood ,flooding caused by upstream development and undersized private stormwater infrastructure in the project area. COMP. PLAN .. DESIGNATIONS: The Comprehensive Plan Land Use designation for the .property is Residential Low Density. Adjacent Comprehensive Plan designations are as follows: North: Residential Low Density South: Residential Low Density. East: Residential Low Density West: Residential Low Density rrcr-imEn F ^n� CpNWJNITY QV 01.0R:4,1E1'4T ZONING DESIGNATIONS: The Zoning for the property is UL 7,200 (Urban Low Density Residential). Adjacent Zoning designations are as follows: North: Urban Low Density Residential (UL 7,200) South: Urban Low Density Residential (UL 7,200) East: Urban Low Density Residential (UL 7,200) West: Urban Low Density Residential (UL 7,200) A. BACKGROUND Pursuant to WAC 1.97 =11- 340(2), the City of SeaTac is required to send this determination to DOE and other agencies with, jurisdiction, affected tribes, and other interested parties. B. ENVIRONMENTAL ELEMENTS 1. Earth: Concur with checklist. The removal /import/stockpile of soil and removal of debris could result in mud, dust, and erosion/sedimentation leaving the site During construction, access may be required for construction material delivery, machine access and construction personnel transportation,which may also contribute to the area of disturbance during construction. dt is anticipated :that approximately 12 cubic yards of existing soil will be removed and/replaced`with.rock: `- . • As stated in the Downstream Analysis Report, prepared by the City of SeaTac, the preliminary geotechnical report identified soils consisting of very dense, slightly silty to silty, sandy gravel and - gravelly sand with, scattered cobbles. The topography of the project area generally slopes downward at up to 15% from northwest to southeast. Topography at the south end of the project area includes a stormwaterdepression; on a; private stormwater tract within the City of Tukwila, with steeper slopes. This depression has slopes up to 75% at the southeast project discharge point. The ravine to the south of the project showed. signs of landslide debris at the top of slopes at 5151: Ave'. South. No instability was noted in the area of the depression south of 53`1 Ave. South. Preparation and implementation of a Temporary Erosion Sediment Control (TESC) plan will .limit erosion leaving the site during grading and construction-activities. Measures to mitigate potential erosion problems include, but are not limited to, dewatering, silt fencing, soil stabilization, covering stockpiled soils, timely restoration of disturbed areas, inlet protection, and street sweeping. Substantive SEPA policies that address this issue include: Policy 8.2A — Design land use development to prevent, property damage and environmental degradation, and enhance greenbelt and wildlife habitat values. • Policy 8.2D — Retain or replace native ground 'cover in development: areas subject to erosion 2IPage hazards. Use special construction practices to reduce site coverage of development to prevent erosion and sedimentation. Consider time limitations on construction work to reduce erosion and sedimentation. Policy 8.2H — Maintain and enhance natural drainage systems to protect water quality, reduce public costs and prevent environmental degradation. Do not alter natural drainage systems without acceptable mitigation measures which eliminate the risk of flooding or negative impacts to water quality. Policy 8.21 — Protect water quality and natural drainage systems by controlling the quality arid quantity of stormwater runoff. Policy 8.2K — Design site plans and construction practices to minimize on -site erosion and sedimentation during and after construction. 2. Air: Concur with checklist: Construction activities will result in localized increases in pollutant emissions from construction equipment: Implementation of reasonable precautions to minimize dust emissions will be used These measures may include, but are not limited to, applying water during dry periods to suppress dust and other air borne particulates, a vehicle wheel wash, and street' cleaners to keep mud and debris off public roadways. Once the project has been completed, the main sources of emissions will be from vehicles coming to and from the project area These will be consistent with current emission level's. Substantive SEPA policies include: Policy 8.2P— Conssider the impacts of new development on air quality as a part of the environmental review process and require any appropriate' mitigating measures. 3. Water: The Sunrise View neighborhood is located on the west side of I -5' in the vicinity of 51st Avenue South andSouth, 170 th Street Prior to the incorporation of the City of SeaTac (City), a storm drainage system was constructed to collect and convey flows from`an upstream area west of Sunrise View. This area is bounded to the west by Military Road, South 164th Street to the north, 5151 Avenue South to the east and South 172nd Place to the south. The flow from this area is conveyed mostly by open ditches and 12 -inch culverts to two discharge points, that direct the flow onto private properties within the Sunrise View neighborhood east of 5151 Avenue South. A three (3) acre parcel on3Td Avenue South within the Tukwila City Limits is adjacent to the Sunrise View neighborhood and also receives a portion of the upstream flows. The storm system between 515` Avenue South and 53'' Avenue South is'on,ptivate property and drainage easements have not been dedicated to the City. Tlieproperty owners are responsible for the maintenance of the storm system, not the City: This storm system is not inspected by the City. Construction activities could lead to short-term disturbance of stream flow, wetland, wetland buffers and water quality. Clearing, grading, 'trenching and backfilling mayresult in soil movement at th'e Site which could lead to soil erosion and diminished water quality. Concrete work could - result in cement entering the water channels. Surface water and ground water may need to be diverted/bypassed.around areas of active construction. Implementation of a Temporary Erosion Sediment Control (TESC) plan will limit erosion leaving the project site during construction activities. Regular inspections by the City ofSeaTac 3 I P u r e Public Works Department will also help monitor for potential erosion impacts and advise the contractor on corrective measures. The bypass pipeline is designed to avoid and protect against any potential impacts to nearby sensitive areas. The following measures will be implemented so as to further limit potential impacts to sensitive areas: • Construction works is scheduled to occur during dry weather months (July to September) so as to reduce potential for erosion and sediment runoff; • All excavation is located outside of identified wetlands and streams; • Source Control Best Management Practices (BMPs) will be implemented and includes the installation of silt fencing and catch basin filters to prevent sediment laden runoff from mixing with clean runoff; • Any disturbed areas, arising as a result of construction activities, will be stabilized and protected against erosion at the end of each work day with vegetated areas restored at the completion of construction activity; • Additionally, other BMPs will be implemented including the installation of gabion energy dissipaters at the natural discharge locations to disperse runoff and the installation of Flow Restrictive /Oil Pollution (FROP) -Tee fittings at the catch basin outlets to serve as an oil /water separator and to provide water quality treatment; and • Routine maintenance of City stormwater facility structures. It is essential that the proposed project.be undertaken to alleviate urban flooding affecting the adjoining neighborhood. Following a review of a number of alternatives, the proposed pipeline alignment is the only practical alternative available. A number of other options were explored, however, these options were found to have increased impacts on the adjoining nearby areas of wetlands, streams, and steep slopes. One option considered included the installation of a pump station/force main, however, it was considered unfeasible due to its impact to a Class 2 perennial stream, located south of the project, and its adjacent steep sloped bank: A second option evaluated was the utilization of a deep tunnel bore to install a drainage pipe which would discharge runoff to the above mentioned Class 2, stream. The environmental impacts of this option, however, included construction activity.within the stream and along.its steep sloped banks. Following a careful review of the environmental risks and disadvantages of these options, the City determined that the proposed project design, would considerably minimize any impacts to the environment and adjoining neighborhood. SEPA policies applicable are: Policy 8.1B — Manage water resources for multiple uses, including recreation, fish and wildlife, flood protection, erosion control, water supply, energy production, and 'open space. Policy 8.1C— Work with adjacent jurisdictions and other affected entities to enhance and protect water quality in the region. Policy 8.1D — Preserve water quality of natural surface water storage: sites that help regulate stream flows and recharge groundwater. Policy 8.1E — Protect water quality; natural drainage, fish and wildlife habitat, and aesthetic functions of streams, creeks, and lakes. 41 P g; Policy 8.1F — Preserve an undisturbed corridor wide enough to maintain natural functions between new development and streams, creeks and lakes. When impacts from new development are unavoidable, ensure that those impacts result in stream and creek corridors that are wide enough to maintain natural functions between the new development and streams,, creeks, and takes. Policy 8.2D — Retain or replace native ground cover in development areas subject to erosion hazards. Use special construction practices to reduce site coverage of development to prevent erosion and sedimentation. Consider time limitations on construction work to reduce erosion and sedimentation. Policy 8.21— Protect water quality and natural drainage systems by controlling the quality and quantity of storm water runoff. Policy 8.2J— Do not increase peak storm water runoff from new development. Do not increase total runoff quantity from new development in critical drainage, erosion, or flood hazards. Policy 8.2K — Design site plans and construction practices to minimize on -site erosion and sedimentation during and after construction: 4. Plants: Concur with checklist. The environmental checklist indicates that approximately 7,200 square feet of vegetation will be removed, including grasses, small trees and blackberry bushes. 5. Animals: Concur with checklist. 6. Energy and Natural Resources: Concur with checlist. 7. Environmental Health: Concur with checklist Use of construction equipment and powered tools may result in short -term noise generation and dust during clearing, grading and construction. activities. Implementation of standard Best Management Practices will limit and control such emissions. 8. Land and Shoreline Use: Concur with checklist. 9. Housing: Concur with checklist.. 10. Aesthetics: Concur with checklist. 11. Light and Glare: Concur with checklist. 12. Recreation: Concur with checklist. 13. Historic and Cultural Preservation: Concur with checklist. 14. Transportation: Concur with checklist. 15. Public Services: Concur with checklist. 5 16. Utilities: Concur with checklist. C. NON - PROJECT ACTIONS N/A D. CONCLUSION Based on the analysis, the lead agency for this proposal has determined that it does not have a probable significant adverse impact on the environment, and an environmental impact statement (EIS) is not required under RCW 43.21 C.030(2)(c), only if certain conditions are met. This decision was made after review of a completed environmental checklist and other information on file with the lead agency. This information is available to the public on request., The City of SeaTac reserves the right to review any future revisions or alterations to the site or to the proposal in order to .determine the environmental significance or non-significance of the project at that point in time. Prepared By: Albert Torrico, Jr., Senior Planner Anita Woodmass, Associate Planner April 2009 cc: Stephen Butler, FAICP, Planning & Community 'Development Director Jack Dodge, Principal Planner Gary Schenk, Building Official Bob Meyer, Fire Chief Susan Sanderson, City Engineer Dixie Hallenberger, Engineering Tech Supervisor Florendo Cabudol, Civil Engineer 6IPage 4800 South 188th Street SeaTac, WA 98188 -8605 City Hall: 206.973.4800 Fax: 206.973.4809 TDD: 206.973.4808 Mayor Ralph Shape Deputy Mayor Gene Fisher Councilmembers Chris Wythe Terry Anderson Tony Anderson Barry Ladenburg Mia Gregerson City Manager Craig Ward Assistant City Manager Todd Cutts City Attorney Mary Mirante Bartolo City Clerk Kristina Gregg June 23, 2009 Mr. Brandon J. Miles, Senior Planner Department of Community Development City of Tukwila City Hall 6200 Southcenter Boulevard Tukwila, WA 98188 RECETEn UM 2 3 22C COMMUN :j .r DEVELOP14ENT Subject: Application for Special Permission Director Permit for City of SeaTac's Sunrise View Bypass Pipeline project Dear Mr. Miles, The City of SeaTac requests a Special Permission Director Permit to allow a deviation for construction within a wetland buffer area. The deviation is needed to construct a new storm drainage outfall as part of the City of SeaTac's Sunrise View Bypass Pipeline project. The City is constructing the Bypass pipeline to solve localized flooding in the Sunrise View neighborhood. The proposed pipeline discharges to the WSDOT storm drainage system which is immediately adjacent to the Valley View Sewer District pump station site located east of 17025 53`d Avenue South, SeaTac, WA 98188. This project will match existing flows and will not increase flows. The proposed north storm drainage outfall lies within a wetland buffer area within Washington State Department of Transportation Right -of -Way. Proposed mitigation for work within the wetland buffer shall include enhancing an area equivalent to the disturbed buffer area (approximately 425 square feet) with City of Tukwila approved plantings and spaced according to Tukwila standards. An onsite meeting and subsequent correspondence with Sandra Whiting, City of Tukwila Urban Environmentalist, provided SeaTac guidance on mitigating the disturbed buffer area and creating the wetland buffer enhancement plan. Alternatives to working within the wetland buffer are not feasible because the north storm drainage outfall for the project is situated to match the existing discharge location. Construction for this project is scheduled to begin this summer. Please feel free to contact me at any time if there are any questions or concerns regarding this issue. My direct line is 206 - 973 -4740 or you can reach me at fcabudol@ci.seatac.wa.us. Sincerely, Florendo Cabudol, P.E. Civil Engineer 2 Enclosures The Hospitality City Wetland and Stream Reconnaissance Report Sunrise View Stormwater Bypass Alternative Corridors SeaTac, Washington June 19, 2008 Submitted To: Ms. Chris Rhinehart, P.E. PACE Engineers, Inc. 1601 Second Avenue, Suite 1000 Seattle, Washington 98101 By: Shannon & Wilson, Inc. 400 N 34th Street, Suite 100 Seattle, Washington 98103 21 -1- 12258 -001 TABLE OF CONTENTS Page 1.0 INTRODUCTION 1 2.0 SCOPE OF SERVICES 1 3.0 SITE LOCATION 2 3.1 Stormwater Discharge Point A 3 3.2 Stormwater Discharge Point B 3 4.0 PROJECT DESCRIPTION 3 4.1 Alternative 1 3 4.2 Alternative 2 4 4.3 Alternative 3 4 5.0 METHODS 4 6.0 DOCUMENT REVIEW 5 7.0 RESULTS 6 7.1 Stream 1 and-Wetland B 6 7.1.1 Stream 1 6 7.1.2 Wetland B 7 7.2 Potential Stream 2 and Wetland A 7 7.2.1 Potential Stream 2 8 7.2.2 Wetland A 9 7.3 Potential Stream 3 and Potential Wetland C 10 7.3.1 Potential Stream 3 10 7.3.2 Potential Wetland C 11 7.4 Stream 4 and Wetland D 11 7.4.1 Stream 4 12 7.4.2 Wetland D 12 7.5 Uplands 13 8.0 REGULATORY REVIEW 13 8.1 Federal Regulations 13 8.2 • State Regulations 14 8.3 City of SeaTac (City) 15 8.3.1 Wetlands 16 8.3.2 Streams 16 8.4 City of Tukwila 16 2 1 -1 -12258 -001 -R 1 fdoc/wp/FR W RK 21 -1 -12258 -001 TABLE OF CONTENTS (cont.) Page 9.0 REGULATORY SUMMARY AND ANTICIPATED TIME FRAMES 16 10.0 CLOSURE 18 11.0 REFERENCES 20 Table No. 1 Figure No. TABLE Expected Permitting Time Frames Associates with Scenarios 1 to 3 19 LIST OF FIGURES l Vicinity Map 2 Proposed Alternatives Map 3 USDA Soils Map 4 USFWS NWI Map 5 King County iMap 6 SeaTac Wetlands and Streams Map 7 Wetland and Stream Reconnaissance Map APPENDIX Important Information About Your Wetland Delineation /Mitigation and /or Stream Classification Report 21-1-1 2258- 001 -R l f.doc/wp/FR WRK 11 21 -1 -12258 -001 WETLAND AND STREAM RECONNAISSANCE REPORT SUNRISE VIEW STORMWATER BYPASS ALTERNATIVE CORRIDORS SEATAC, WASHINGTON 1.0 INTRODUCTION Shannon & Wilson conducted a wetland and stream reconnaissance within the vicinity of a proposed stormwater bypass pipeline in the Sunrise View neighborhood of SeaTac, Washington (Figure 1). The intent of this wetland and stream reconnaissance was to evaluate three alternatives (Alternatives 1 through 3) to assist PACE Engineers and the City of SeaTac (City) with an alternatives analysis and the future development of a scope and budget associated with constructing the preferred alternative. This report summarizes the findings from our wetland and stream reconnaissance for the Sunrise View stormwater bypass pipeline. 2.0 SCOPE OF SERVICES Shannon & Wilson originally prepared a scope of services to conduct a wetland delineation along the proposed alignments associated with Alternatives 1 through 3. However, at the City's request, this scope of services was informally revised to include a wetland and stream reconnaissance as part of the alternatives analysis and postponed the formal wetland delineation. Once a preferred alternative has been chosen and agreements are reached with private residences, a wetland delineation will be completed. The informal scope of services associated with this wetland and stream reconnaissance is as follows: ■ Conducted a background review of information relating to the site, including a review of the U.S. Department of Agriculture's (USDA's) Web Soil Survey (WSS); U.S. Fish and Wildlife Service (USFWS) National Wetlands Inventory (NWI) map; King County's iMap System; the City's Wetland and Stream Inventory Map; wetland reports as provided by the City; and other relevant materials. ■ Performed a wetland reconnaissance in the vicinity of Alternatives l through 3 alignments, City rights -of -way (ROWs), and private properties where access had been granted. Methodology for this wetland reconnaissance was modified from the Washington State Wetland Identification and Delineation Manual (Washington State Department of Ecology [Ecology] Publication No. 96 -94) and 1987 U.S. Army Corps of Engineers (Corps) Wetland Delineation Manual (Wetlands Research Technical Report 2 I -1- 12258 -00I -R I f.doc/wp/FR W RK 1 21- 1- 12258 -001 Y- 87 -1). This includes rating wetlands using Section 15.30 (Environmentally Sensitive Areas) of the SeaTac Municipal Code (SMC) and Section 18.45.080 (Environmentally Sensitive Areas) of the Tukwila Municipal Code (TMC). ■ Identified streams as defined under SMC 15.10, TMC 18.06.920, and as potentially regulated by the Washington State Department of Fish and Wildlife (WDFW) or Ecology as waters of the State or by the Corps as waters of the United States. This includes a review of historical aerial photographs dating back to the 1930s. ■ Completed a wetland and stream reconnaissance report describing our findings for use within the consideration of Alternatives 1 through 3. This report includes a regulatory review of the wetlands and streams as it pertains to Alternatives 1 through 3. The report includes a site sketch including the approximate boundaries of any identified wetland and stream. 3.0 SITE LOCATION The stormwater bypass project is proposed within the Sunrise View neighborhood, near the intersection of South 172nd Street and 51st Avenue South. The legal description of the project is the SW '/4 of Section 26, Township 23 North, Range 4 East, Willamette Meridian (Figure 1). The project is located within Water Resource Inventory Area (WRIA) No. 9 (Duwamish /Green) and Hydrologic Unit Code (HUC) 17110013. While most of the potential alternative alignments are located within the city limits of the SeaTac, a recently subdivided property at the southern terminus of 53`d Avenue South is within the City of Tukwila. It is our understanding that the City of Tukwila is aware of this project and has been cooperating with the City on this project. Properties within the project area are predominantly developed for single families with the exception of two lots comprising a large ravine along the southern boundary of the proposed alignments. The Sunrise View neighborhood is currently zoned Urban Low- Density Residential (UL- 7,200). Topography throughout the Sunrise View neighborhood in the vicinity of the proposed alternatives gradually slopes from northwest to southeast. However, topography west and northwest of the proposed alignments includes eastwardly sloping hills dominated by single- family residences that convey stormwater through a series of open ditches and culverts toward the project area. Based on stormwater conveyance maps provided by PACE Engineers, stormwater from these west hills appears to be dispersed near the project area at two points, Stormwater Discharge Points A and B. 21- 1- 12258- 001 -R 1 f:doc/wp/FR W RK 2 21 -1 -12258 -001 3.1 Stormwater Discharge Point A Stormwater Discharge Point A is located near the southeast corner King County Parcel No. 81252 -00130 (Glimberg Property), at 17022 51st Avenue South. This discharge point releases stormwater from the neighborhood northwest of the project area into a low point on the block and is eventually picked up in another conveyance system. This conveyance system directs stormwater through a series of open ditches to an unnamed tributary to Gilliam Creek located behind an existing pump station east of 53`d Avenue South. 3.2 Stormwater Discharge Point B Stormwater Discharge Point B, located on the northwest corner of King County Parcel No. 81252 -00171 (Seysan Property), at 17046 51st Avenue South, discharges into an open ditch. The ditch conveys stormwater to the southeast, where it enters a series of pipes before eventually entering a culvert that conveys stormwater below Interstate 5 (1 -5) and into the Tukwila drainage system. 4.0 PROJECT DESCRIPTION The intent of the stormwater bypass project is to collect and convey stormwater that presently floods private properties to the southeast into an appropriate drainage. The project currently includes three alternatives developed by the City and PACE Engineers, all of which would begin approximately 200 feet north of the intersection of South 172nd Street and 50 Avenue South (Figure 2). All three alternatives propose to maintain base flows to wetlands and streams while bypassing peak flows. It is our understanding that the City has placed a moratorium on further expansion of impervious surfaces throughout a portion of the Sunrise View neighborhood because of the severity of the flooding within the project area. No additional impervious surfaces are permitted until this stormwater bypass pipeline is constructed to alleviate flooding of downstream residents. 4.1 Alternative 1 Alternative l is a cut - and -cover force main along 51St Avenue South, originating at a proposed pump station located about 200 feet north of the intersection of South 172nd Street and 51st Avenue South. The pipeline would terminate in the bottom of the steep ravine located on the Mill Creek Ventures Property. Stormwater would be dissipated at the outfall and flow east 2 I -1 -12 25 8- 001 -R 1 fdoc/wp/FR W RK 3 21 -1 -12258 -001 through a stream and an associated wetland within a steep ravine before entering a concrete drop culvert under I -5. 4.2 Alternative 2 Alternative 2, similar to Alternative 1 with the exception of the pipeline constructed as a gravity tunnel along 51st Avenue South, starts at the collection system in 51St Avenue South and terminates in the bottom of a steep ravine south of the southern terminus of 51St Avenue South on King County Parcel No. 26230 -49013 (Mill Creek Ventures Property). Stormwater would be dissipated at the outfall and flow west to east through a stream and associated wetland within a steep ravine before entering a concrete drop culvert under I -5. 4.3 Alternative 3 Alternative 3 is a cut - and -cover gravity pipeline along the South 172 "d Street ROW to the west of 51St Avenue South, extending eastward through private property to 53`d Avenue South. Once on 53`d Avenue South, the alignment continues south and releases into an existing culvert under 1 -5. 5.0 METHODS Shannon & Wilson, Inc. conducted the wetland and stream reconnaissance fieldwork on May 14 and June 4, 2008. Potential wetlands were identified using modified methods described in the 1987 Corps Wetland Delineation Manual and the Ecology 1997 Wetlands Identification and Delineation Manual. A Shannon & Wilson biologist observed existing site conditions by walking public portions of the proposed alignments and those parcels where property access was granted (King County Parcel Nos. 81252- 00171, 81252- 00170, 26230 - 49013, and 27230 - 49016). Potential wetland areas were determined using the triple - parameter approach, which considers vegetation types, soil conditions, and hydrologic conditions. For an area to be considered wetland, it must display each of the following: (a) dominant plant species that are considered hydrophytic by the accepted classification indicators, (b) soils that are considered hydric under federal definition, and (c) indications of wetland hydrology, in accordance with federal definition. 21-1 -12258 -001 -R 1 f.doc /wp /FRW RK 4 21 -1 -12258 -001 6.0 DOCUMENT REVIEW Background information pertaining to the site was collected and reviewed for its usefulness. The information sources included: ► USFWS NWI Mapping System (Wetlands Mapper) (http://wetlandsfws.er.usgs.gov/NWI/index.html) ► King County iMap Geographic Information System (GIS) Mapping System ( http: / /www.metrokc.gov /gis /mapportal /iMAP main.htm) ► USDA Natural Resource Conservation Service (NRCS) WSS (http://websoilsurvey.nrcs.usda.gov/app/) ► SeaTac Wetland and Stream Classifications Map (SeaTac, 2007) ► SMC, Chapter 15.30, Environmentally Sensitive Areas (http://www.codepublishing.com/wa/seatac/) ► TMC, Chapter 18.45, Environmentally Sensitive Areas ( http: / /www.ci.tukwila .wa.us /clerk/tmc /tmctoc.pdf) The NRCS WSS identifies the project area as containing soil of Arents, Alderwood material, and 6 to 15 percent - slopes (AmC) (Figure 3). Urban land (Ur) and - Alderwood and Kitsap soils, very steep (AkF) soils, are located to the east of the project. Soils are not identified west of 50 Avenue South. None of the listed soils in the vicinity of the project area are considered hydric soils according to the NRCS Hydric Soils List for King County (USDA, 2001). According to the USFWS NWI Map, an unnamed stream flows west to east along the southern portion of the proposed alignments, although no wetlands are located within the project area (Figure 4). This unnamed stream corresponds to Stream I within the steep ravine located along the south end of the project area, where Alternatives 1 and 2 are proposed to discharge (see Section 7.1 below). The USFWS NWI map depicts this unnamed stream flowing east, past the project area, and below I -5 before turning north then east into a large, palustrine, unconsolidated bottom, permanently flooded, excavated (PUBHx) and palustrine, emergent, temporarily flooded (PEMA) wetland system. Based on conversations with Ryan Larson, Senior Surface Water ■ Management Engineer with the City of Tukwila, this downstream flow path depicted on the USFWS NW! Map is incorrect (Dodge, 2008). King County iMap identifies no wetlands within the project area (Figure 5). However, an unnamed and unclassified stream is located to the south of the project area in the ravine on the 21 -1 -1225 8 -001 -R l f.doc/wp/FR W RK 5 21 -1- 12258 -001 Mill Creek Ventures Property, where Alternatives 1 and 2 propose to discharge. This unnamed stream corresponds to Stream I described within Section 7.1 below. The City's Wetland and Streams Map depicts a Class 2 wetland north of the project area with a stream exiting the wetland to the east and a Class 2 stream located south of the project area within a ravine (Figure 6). Based on conversations with City staff and a review of wetland reports prepared for the City, the Class 2 wetland and stream to the north of the project site are located on the Glimberg Property and east of Stormwater Discharge Point A. This wetland and stream also correspond to Wetland A and Potential Stream 2, as described within Section 7.2 below. The Class 2 perennial stream with undetermined salmonid use located to the south of the project area corresponds Stream 1, as described in Section 7.1 below. 7.0 RESULTS Three wetlands (Wetlands A, B, and D), one potential wetland (Potential Wetland C), two streams (Streams 1 and 4) and two potential streams (Potential Streams 2 and 3) are located within the vicinity of the project area (Figure 7). Wetlands were classified under both the Cowardin classification system (Cowardin et al., 1985) and hydrogeomorphic classification system (HGM) (Brinson, 1993). Wetlands and streams were also classified under SMC 15.10.675 and SMC 15.10.620, respectively. Streams were further classified using the Washington State Water Typing System as defined within Title 222 -16 -031 (Forest Practices Rules) of the Washington Administrative Code (WAC). 7.1 Stream 1 and Wetland B Stream 1 and Wetland B are located at the toe of a steep ravine on the Mill Creek Ventures Property (Figure 7). 7.1.1 Stream 1 Stream 1 is ,a perennial flowing stream, which corresponds to the unnamed stream identified on the USFWS NWI Map (Figure 4), King County iMap (Figure 5), and SeaTac Wetland and Streams Map (Figure 6). Stream 1 flows west to east through a steep ravine on the Mill Creek Ventures Property within a defined channel comprised of well - rounded gravels and cobbles. The active channel at the time of our site visit was approximately 3 feet wide, although the width between ordinary high water marks (OHWMs) was approximately 10 to 15 feet. 21-1-12258-001-RI f.doc /wp/FR W RK 6 21- 1- 12258 -001 The upstream reaches of Stream 1 are unknown; however, the stream exits the ravine in a concrete drop culvert before flowing under I -5. Based on flow paths depicted on as -built plans for 1 -5 obtained by PACE Engineers, it is our understanding that Stream 1 flows northeast under 1 -5 and enters a pressurized 66 -inch pipe that conveys flow south along Southcenter Parkway before turning east at South 180th Street and discharging into the lower Green River (Larson, 2008). This downstream flow path differs from the flow path illustrated in Figures 4 and 5. Stream 1 is not accessible to anadromous salmonids and is not used by residential salmonids. According to the City's Wetlands and Streams Map, Stream 1 is classified as a Class 2 perennial stream with undetermined salmonid use. While salmonids do not use Stream 1, the City's Class 2 stream designation is appropriate based on the presumed perennial flow. Class 2 streams not used by salmonids have a standard buffer of 50 feet. According to the Washington Stream Typing System, Stream A would be classified as Type Np water, because it is non -fish bearing and supports perennial flow. 7.1.2 Wetland B Wetland B is a palustrine, emergent/scrub- shrub, intermittently flooded (PEM /SSJ) wetland under the Cowardin classification system and riverine wetland under the HGM classification system. This wetland follows the left (north) bank of Stream I within the steep ravine on the Mill Creek Ventures Property (Figure 7). Wetland B appears to be predominantly supported by seeps along the toe of the slope, although it is also assumed to receive over -bank flooding from Stream 1 during significant rain events. Soils in Wetland B are comprised of saturated loams near the edge of the wetland, with increasingly coarse sand and gravel composition closer to Stream I. Vegetation throughout Wetland B includes an emergent strata dominated by skunk cabbage (Lysichiton americanus, OBL) and ladyfern (Athyrium filix femina, FAC), with a shrub strata dominated by salmonberry (Rubus spectabilis, FAC +). Under SMC 15.10.675, Wetland B would be classified as a Class 3 wetland, assuming the total wetland area does not equal greater than 1 acre or contain raptor nesting trees. Class 3 wetlands have a standard buffer of 35 feet. 7.2 Potential Stream 2 and Wetland A Potential Stream 2 and Wetland A are located on the Glimberg Property on the north end of the project area (Figure 7). Due to an ongoing dispute, close observation of Potential Stream 2 and 21 -1 -12258 -001 -R I f.doc/wp/FR W RK 7 21 -1 -12258 -001 Wetland A was not possible during this reconnaissance. Direct observations of Wetland A are based on observations conducted from 51St Avenue South and the northern extent of King County Parcel No. 81252 -00170 (Gipson Property). Potential Stream 2 was not directly observed. 7.2.1 Potential Stream 2 Potential Stream 2 is an excavated ditch that begins from the outlet of Stormwater Discharge Point A on the Glimberg Property and ends in an undersized, 8 -inch culvert on King County Parcel No. 81252 -00505 (Giovanni Property) (Figure 7). The following are descriptions of the Potential Stream 2 as prepared by previous wetland reports submitted to the City: There is an 18 -inch diameter corrugated metal pipe (CMP) storm system culvert that enters onto the site (Glimberg Property) from the west. This pipe traverses the site along the southern boundary for approximately 185 feet. The pipe then discharges and a stream continues across the site in a northeasterly direction, leaving the site near the northeastern corner. PAC -TECH Engineers, 1991 (Page 2) It should be noted that both, at the time of site reconnaissance (June 20,1991) and formal wetland delineation (August 9, 1991), there was a significant water discharge from the storm culvert that enters onto the site. The stream that begins at the culvert discharge point (Stormwater Discharge Point A) traverses the site in a northeastly direction and leaves the site near the northeast property corner. The drainage analysis prepared by Summersett 0990) indicates that the stream eventually enters into the Interstate 5 drainage system." PAC -TECH Engineers, 1991 (Page 7) The onsite stream conveys surface water through the site (Glimberg Property) generally from the west to the northeast. This stream originates offsite and upslope of 51s1 Avenue South. This stream continues offsite to the east within an excavated ditch. Via a series of culverts and ditches surface water from the project site (Glimberg Property) eventually enters the Lower Green River. This stream meets the criteria for classification as riverine, intermittent, streambed, seasonally flooded (R43BC) and meets the criteria for designation as a City of SeaTac Class 3 stream. Habitat Technologies, 2001 (Page 5) Based on these descriptions, it appears that Potential Stream 2 would be regulated by the City as a Class 3 stream unless documentation, such as historical aerial photographs, illustrate that the stream was created intentionally in upland areas to convey stormwater. Class 3 streams 21 - 1- 12258- 001 -R l f d oc/wp/FR W RK 8 21 -1- 12258 -001 have a standard buffer of 25 feet. In addition, the Corps, Ecology, and WDFW have the opportunity to make their own jurisdictional determination regarding Potential Stream 2. According to the Washington Stream Typing System, Potential Stream 2 would be classified as Type Ns water because it is a seasonal, non -fish bearing stream. 7.2.2 Wetland A Wetland A appears to be a palustrine, emergent/forested, seasonally - flooded (PEM/FOC) wetland under the Cowardin classification system and depressional wetland under the HGM classification system. Wetland A is located within a shallow depression on the east side of the Glimberg Property and corresponds to the wetland identified on the SeaTac Wetlands and Streams Map (Figure 6 and 7). It appears that Wetland A also extends south onto a portion of King County Parcel No. 81252 -00160 (Jacobsen Property). Based on previous wetland delineation reports prepared for the Glimberg Property (formerly Preston and Norris properties), Potential Stream 2 flows west to northeast through Wetland A. These previous wetland delineation reports, prepared by PAC -TECH Engineers (1991), Habitat Technologies (2001), and Karuna Environmental Services (2002) document Wetland A. According to Habitat Technologies (2001), dominant vegetation within Wetland A include skunk cabbage (Lysichiton americanus, OBL); ladyfern (Athyrium filix femina, FAC); reed canarygrass (Phalaris arundinacea, FACW); red -osier dogwood (Cornus sericea, FACW); red alder (Alnus rubra, FAC); Oregon ash (Fraxinus latifolia, FACW); black cottonwood (Populus trichocarpa, FAC); and willow species (Salix spp.). Soils throughout Wetland A have also been described as black (10YR2 /1) to very dark gray (10YR3/1) with redoximorphic features such as mottles, oxidized root channels, and organic streaking (Habitat Technologies, 2001). Direct observations of the soils during our reconnaissance could not be made. Wetland A appears to be hydrologically supported by overland flow from adjacent uplands, precipitation, and a high groundwater table. However, the primary hydrologic support to Wetland A is believed to be Stormwater Discharge Point A, which releases stormwater into Potential Stream 2 that flows through Wetland A. The following is the hydrologic description for Wetland A as described within wetland reports submitted to the City: At this period in time, it appears that this wetland is dependant on the off-site collection of stormwater and discharge via the above noted system (Stormwater 21 -1 -12258 -001 -R 1 f.doc /wp/FRW RK 9 21 -1 - 12258 -001 Discharge Point A and Potential Stream 2). This municipal system is the feature that keeps this wetland system viable. In all probability, the eastern portion of this site was a wetland within a historic (pre - settlement) perspective. The present stormwater discharge, through the culvert, is the mechanism that has recently kept this wetland viable while urbanization has occurred about it and adjacent wetland areas have been completely filled... There is undoubtedly some surface and subsurface water flow onto the site from adjacent properties to the north where the topography rises considerably. However, this contribution is relatively insignificant in consideration of the major discharge from the storm system culvert. PAC -TECH Engineers, 1991 (Page 7) The portion of Wetland A located on the Glimberg Property is well documented as a result of the ongoing wetland dispute. The City has currently classified Wetland A as a Class 2 wetland. Class 2 wetlands have a standard buffer of 50 feet. 7.3 Potential Stream 3 and Potential Wetland C Potential Stream 3 and Potential Wetland C originate from Stormwater Discharge Point B on the Seyson Property (Figure 7). This potential stream and wetland system extend east along the Seyson Property and south between the Seyson and Gipson Properties before continuing in a southeast direction. 7.3.1 Potential Stream 3 Potential Stream 3 is a seasonal drainage that originates from Stormwater Discharge Point B within a narrow ditch approximately 3 feet deep to a 12 -inch concrete culvert outside the project area. Flow continues through a highly modified conveyance system that includes closed pipes, riprap -lined channels, and a gabion basket before it enters a drop culvert approximately 10 feet deep. From this point, flow continues east under I -5, converges with the culvert conveying Stream 1, and continues along the same downstream flow path as Stream 1. Potential Stream 3 was historically classified as a Class 3 stream by the City. However, on August 8, 2000, the City determined Potential Stream 3 to be a "manmade drainage ditch" following a review of the drainages classification as part of a violation on King County Parcel No. 81252 -00200 (Discher Property). The City changed their stream classification based on information provided by Mr. Discher, which included a review of 1936 aerial photographs. 21- I -I2258 -001 -R1 f.doc /wp/FRWRK 10 21 -1- 12258 -001 Due to the City's determination of Potential Stream 3 as a manmade drainage ditch, this drainage is not subject to the City's Environmentally Sensitive Regulations (SMC 15.30). However, the Corps, Ecology, and WDFW have the opportunity to make their own jurisdictional determination (see Section 8.0 below). According to the Washington Stream Typing System, Potential Stream 2 would be classified as Type Ns water because it is a seasonal, non -fish- bearing stream. 7.3.2 Potential Wetland C Potential Wetland C is a palustrine, emergent, temporarily flooded (PEMA) wetland under the Cowardin classification system and riverine wetland under the HGM classification system. Hydrologic sources to Potential Wetland C include precipitation, high groundwater table, and stormwater from the residential neighborhood to the west released from Stormwater Discharge Point B. A sump pump associated with the single - family residence on the Seyson Property was observed discharging groundwater into the ditch at the time of our site visit. Based on conversations with City personnel and local residents, Potential Stream 3 periodically floods during heavy rain events. Dominant vegetation throughout Potential Wetland C includes creeping buttercup (Ranunculus repens, FACW) and mowed grasses (presumably reed canarygrass (Phalaris arundinacea, FACW). Red alder (Alnus rubra, FAC); ladyfern (Athyrium filix femina, FAC); soft rush (Juncus effusus, FACW); Himalayan blackberry (Rubus armeniacus, FACU); and giant horsetail (Equisetum telmateia, FACW) were also present throughout Potential Wetland C. Potential Stream 3 was determined as a "manmade drainage ditch" by the City in 2000. Therefore, it is likely that the City would consider this potential wetland as part of that manmade drainage ditch and not subject to City regulations, including buffers. However, both the Corps and Ecology have the opportunity to make their own jurisdictional determination for Potential Wetland C (see Section 8.0 below). 7.4 Stream 4 and Wetland D Stream 4 and Wetland D are located east of the existing pump station along 53rd Avenue South, within Tukwila city limits (Figure 7). 21-1- 12258- 001 -R l f.doc/wp/FRW RI{ 11 21 -1 -12258 -001 7.4.1 Stream 4 Stream 4 is an unnamed tributary to Gilliam Creek that originates east of the pump station along 53`d Avenue South. This tributary flows north - northeast through a poorly defined channel within Wetland D between I -5 and adjacent residences. Stream 4 is largely supported by stormwater from two locations. The first source is surface water that exits Stormwater Discharge Point A and flows through Wetland A/Potential Stream 2 prior to continuing through a series of ditches and pipes that ends in an undersized 8 -inch pipe on the Giovanni Property. The second source is stormwater detained in a stormwater vault in South 170th Street to the north. Because of these sources, it is presumed that flow within Stream 4 is seasonal. The following is a description of Gilliam Creek's downstream flow path: Gilliam Creek is an altered and relocated stream channel that originates near the boundary between SeaTac and Tukwila near South 158th Street. The stream flows from the upland plateau to the river within relatively natural channels, constructed channels, and piped conveyance systems. The stream drains along the south and north sides of State Route (SR) 518 and is intercepted by the WSDOT storm drainage infrastructure within Interstate 5. It enters a constructed channel along Southcenter Parkway and flows into the Lower Green River just south of the Interstate 405 bridge. A large flap -gate flood control structure is located at the creek's outfall to protect Tukwila's business district, known as the Tukwila Urban Center (TUC), from backflow during high flow levels in the river. Despite . the flap gate, salmonids use the lower portions of Gilliam Creek. ESA Adolfson, 2007 (Section 4.2.1.1) Based on the presumed seasonal flow and lack of fish use in Stream 4, this stream would be classified as a Type 4 watercourse by the City of Tukwila. Type 4 watercourses require standard 50 -foot buffers. According to the Washington Stream Typing System, Stream A would be classified as Type Ns water because it is a seasonal, non -fish- bearing stream. It is our understanding that the proposed alternatives would not currently impact Stream 4. 7.4.2 Wetland D Wetland D is a palustrine, emergent, seasonally- flooded /saturated (PEME) wetland under the Cowardin classification system and riverine wetland under the HGM classification system. Wetland D appears to be largely supported by stormwater that flows beneath the pump station and discharges into Stream 4, between the pump station and I -5. Vegetation within Wetland D is dominated by reed canarygrass (Phalaris arundinacea, FACW); yellow flag iris (Iris 21 -1 -12258 -001 -R I f.doc/wp/FR W RK 12 21-1-12258-001 pseudacorus, OBL); broadleaf cattail (Typha latifolia, OBL); and red alder (Alnus rubra, FAC). Soils were not directly observed during our wetland and stream reconnaissance. Under TMC 18.45.080, Wetland D would be classified as a Type 3 wetland, assuming the wetland, which appears to continue to the northeast, does not equal greater than 1 acre or provide nesting for priority species as defined by WDFW. Type 3 wetlands have a standard buffer of 50 feet. It is our understanding that the proposed alternatives would not currently impact Wetland D. 7.5 Uplands The upland areas within the project area predominantly include single - family residences, landscaped yards, paved roads, gravel driveways, and road side ditches along the west side of 51st Avenue South and 53`d Avenue South. The steep ravine on the Mill Creek Ventures Property is an undeveloped mixed forest. Illegal dumping has been occurring south of 51st Avenue South into the ravine. The forest overstory within this area includes Douglas fir (Pseudotsuga menziesii, FACU); western red cedar (Thuja plicata, FAC); bigleaf maple (Acer macrophyllum, FACU); and red alder (Alnus rubra, FAC). The understory throughout the ravine (where illegal dumping had not occurred) included such shrub and herbaceous species as sword fern (Polystichum munitum, FACU); Indian plum (Oemleria cerasiformis, FACU); vine maple (Acer circinatum, FAC -); and red elderberry (Sambucus racemosa, FACU). Where dumping has occurred, vegetation was dominated by Himalayan blackberry (Rubus armeniacus, FACU); English ivy (Hedera helix, NI); and stinging nettle (Urtica dioica, FAC +). 8.0 REGULATORY REVIEW Several federal, state, and local regulations apply to development proposals in and /or near wetlands and streams. A summary of applicable regulatory implications is given below. 8.1 Federal Regulations The Corps implements the federal Clean Water Act (CWA) Section 404 review process, which is required for projects involving discharges of dredges or fill materials into the waters of the United States, including non - isolated wetlands and streams. Any proposed work located within a jurisdictional wetland will require a nationwide permit (NWP) or an individual permit from the Corps. Since the wetlands and streams within the project area are predominantly, driven by stormwater, with the exception of Stream 1, and flow into a highly modified and ditched 21 -1 -12258 -001 -R 1 fdoc/wp/FRW RK 13 21 -1 -12258 -001 conveyance system throughout the City of Tukwila, it is unknown whether the Corps would take jurisdiction over these wetlands and streams. Based on our experience, however, it is our opinion that the Corps would likely regulate these wetlands and streams. The final determination can be made only by the Corps and the U.S. Environmental Protection Agency (EPA). Following a formal wetland delineation and at the City's request, the Corps and EPA can conduct a Jurisdictional Determination as to whether the CWA Sections 404 and 401 (see Section 6.2 below) apply to these wetlands. For proposed projects that include impacts to wetlands regulated by the Corps, the applicant would need to demonstrate to the Corps that avoidance and minimization measures were implemented. Unavoidable impacts to wetlands would then need to be mitigated through compensatory mitigation that follows both (a) the requirements within the Compensatory Mitigation for Losses of Aquatic Resources, Final Rule (73 FR 19594, April 10, 2008), and (b) the Wetland Mitigation in Washington State guidance document, prepared by Ecology, EPA, and the Corps (Ecology, 2006). If no impacts to wetlands or streams were proposed by the project, then the CWA Section 404 permit would not be applicable. 8.2 State Regulations Ecology has been authorized by the EPA to issue the CWA Section 401 Water Quality Certification for most projects that require the Corps permits under CWA Section 404 (see Section 8.1 above). The certification process ensures that federally permitted activities comply with the federal CWA, state water quality laws, and any other applicable state laws. Some general requirements for Section 401, if it is required, include pollution spill prevention and response measures, disposal of excavated or dredged material in upland areas, use of fill material that does not compromise water quality, clear identification of construction boundaries, and provision for site access to the permitting agency for inspection. If no impacts to wetlands or streams were proposed by the project, then the CWA Section 401 Water Quality Certification would not be applicable. However, Ecology also has authority to regulate wetlands under the State Water Pollution Control Act (Revised Code of Washington [State] [RCW] 90.48) and the State Water Quality Standards (Chapter 173 -201A of the WAC). Therefore, wetlands or streams considered non jurisdictional under the federal CWA or SMC (see Section 8.3 below) may still be considered jurisdictional at the state level and require mitigation if impacted. Ecology would need to make their isolated wetland determination if the 21 -1 -12258 -001 -R l f doc/wp/FR W RK 14 21 -1- 12258 -001 Corps and EPA determined any or all of the project area wetlands and streams were non - jurisdictional and not subject the CWA. For proposed impacts to wetlands regulated by Ecology, it would need to be demonstrated to Ecology that avoidance and minimizations measures were implemented. Unavoidable impacts to wetlands would then need to be mitigated through compensatory mitigation that follows the joint guidance, Wetland Mitigation in Washington State, prepared by Ecology, EPA, and the Corps (Ecology, 2006). Additionally, WDFW has authority to regulate those activities that propose to, alter the flow of fresh water or saltwater of the state under the Hydraulic Code Rules (WAC 220.110) and Construction Projects in State Waters (RCW 77.55). The determination as to whether or not the project area streams and /or manmade drainage ditches qualify as a fresh water of the state is the responsibility of WDFW. In the event that any or all of these features are considered a fresh water of the state, a Hydraulic Project Approval (HPA) must be issued for any proposed activity that may occur below, within, or above the OHWM of that fresh water of the state. 8.3 City of SeaTac (City) The City regulates -areas it considers environmentally sensitive, including wetlands and stream through SMC 15.30. However, it is our understanding from the minutes of an internal City meeting on May 6, 2008, and from conversations with Jack Dodge, principal planner with the City, that the planning department may consider this project as wholly exempt under SMC 15.30.050 (Dodge, 2008). These meeting minutes were provided by Florendo Cabudol with the City. From our review of the exemptions under SMC 15.30.050, it appears that the proposed stormwater bypass pipeline project may qualify for Exemption C4 under SMC 15.30.050, which allows for: Relocation or maintenance of sanitary and storm sewer systems, public water local distribution, natural gas, cable communication or telephone distribution and collection facilities, lines, pipes, ditches, mains, equipment or appurtenances, only when required by a local governmental agency which approves the new location of the facilities. In the event the City does not determine this project to be exempt, the following regulations would be required under SMC 15.30. 21-1-12258-001-RI f.doc /wp/FRW RK 15 21- 1- 12258 -001 8.3.1 Wetlands Under SMC 15.10.675, the City classifies all wetlands using a three - tiered rating system. Using this rating system, Wetlands A and B would be classified as Class 2 wetlands. However, Potential Wetland C would not be considered a regulated wetland because of its hydrologic association with Potential Stream 3. The City's wetland definition does not include drainage ditches used as part of an approved public storm drainage system that may support wetland vegetation or retention /detention systems, such as Potential Stream 3. Class 2 wetlands require a standard buffer of 50 feet. Wetland buffer modification may be allowed through buffer averaging under SMC 15.30.290(B), provided the averaging configuration provides additional protection to the wetland and the net buffer area is not reduced. 8.3.2 Streams Streams are also classified within the City using a three tiered rating system. Using this rating system, Streams 1 and 4 would be classified as Class 2 streams because of their presumed perennial flow. Potential Stream 2 would be classified as a Class 3 stream, presuming the stream was not intentionally created in uplands to convey stormwater. Potential Stream 3 has been determined by the City to be a manmade drainage ditch and not subject to the City's Environmentally Sensitive Regulations. Under SMC 15.30.340, Class 2 streams with no use by salmonids have a standard buffer of 50 feet. Class 3 streams require a standard buffer of 25 feet. Stream buffer modification may be allowed through buffer averaging under SMC 15.30.340(B), provided the averaging configuration provides additional protection to the wetland and the net buffer area is not reduced. 8.4 City of Tukwila It is our understanding that the 'proposed alternatives would not currently impact wetlands, streams (e.g., watercourses), or associated buffers within the City of Tukwila. Therefore, development regulations within the TMC pertaining to these features were not part of this regulatory review. 9.0 REGULATORY SUMMARY AND ANTICIPATED TIME FRAMES All three alternatives determined by the City and PACE Engineers may require the construction of stormwater facilities in or adjacent to wetlands and streams regulated by the Corps, Ecology, 21 -1 -12258 -001 -R I f.doc /wp /FR W RK 16 21 -1 -12258 -001 WDFW, and City. Additionally, each alternative may propose to modify stream flow within streams. Therefore, potential regulatory restraints and associated permitting time frames are dependent upon the details associated with the final design and not necessarily dependent on the alternative alignments. The following are potential regulatory restraints anticipated, given our current understanding of the generalized project design: ■ Construction of a dissipater structure within Stream 1 or Wetland B (Alternatives 1 and 2). ■ Construction of the west -east portion of the proposed Alternative 3 alignment within regulated wetlands (Wetland A or Potential Wetland C) (Alternative 3). ■ Piping any portion of Potential Stream 3 along the west -east section of Alternative 3. ■ Modifying (reducing) flow within Potential Stream 2, Potential Stream 3, and Stream 4 (Alternatives 1 through 3). Because of the similarity of these alternatives, three potential scenarios are described below. ■ Scenario 1. In the unlikely event that the Corps, Ecology, and WDFW do not consider the project area wetlands and streams to be jurisdictional, the project would not need permits from these agencies. Additionally, it is our understanding that the City will consider this project exempt from the City's code. Table 1 estimates the potential time frame associated with this scenario. ■ Scenario 2. If the project can be designed to avoid placing any portion of the stormwater bypass pipeline within a regulated wetland or stream, the project would not require a Section 404 permit from the Corps or Section 401 certification from Ecology. This would likely save the project months of permitting time. However, because of the project's likely modification of stream flows, the project would need an HPA from WDFW. Table 1 estimates the potential time frame associated with this scenario. ■ Scenario 3. If the project includes impacts to wetlands or streams, such as: (a) constructing the dissipater structure within Stream 1 /Wetland B (Alternatives 1 and 2), (b) piping any portion of Potential Stream 3, or (c) impacting Wetland A or Potential Wetland C (Alternative 3), the project would need a Section 404 permit from the Corps and Section 401 certification from Ecology. To satisfy Sections 401 and 404 of the CWA, an NWP 43 (Stormwater Management Facilities) would likely be required. Under NWP 43, preconstruction notification (PCN) to the Corps must occur prior to construction. As a condition of approval, a biological evaluation to address impacts to threatened and endangered species under the Endangered Species Act would need to be approved. Following completion of the PCN to the Corps, Ecology would review the NWP 43 application for certification under Section 401. Additionally, WDFW must issue an HPA prior to construction. A Joint Aquatic Resource Permit Application 2 I -1 -12258 -001 -R 1 fdoc/wp/FR W RK 17 21 -1 -12258 -001 (JARPA) would be necessary as the NWP 43 permit, Section 401 Certification, and the HPA application. Table 1 estimates the potential time frame associated with this scenario. To facilitate a unified jurisdictional determination amongst the Corps, Ecology, WDFW, and the City to the greatest extent possible, we recommend a site visit, scheduled with all potential regulatory agencies, once a preferred alternative is selected. Of these three scenarios, however, Scenarios 2 or 3 are most likely. Once the jurisdictional determinations of these agencies are made and the design details are more fully developed for the selected alternative, the ultimate regulatory restraints and associated permitting time frames can be more accurately assessed. TABLE 1 EXPECTED PERMITTING TIME FRAMES ASSOCIATED WITH SCENARIOS 1 AND 3 Scenario Expected MEG Scenario Frames* Scenario City SMC 15.30 ** N/A N/A N/A Corps Section 404 (Clean Water Act) N/A N/A 6 to 12 months Ecology Section 401 (Clean Water Act) N/A N/A 6 to 12 months WDFW HPA * ** N/A 45 days following submittal 45 days following submittal Notes: * Expected time frames are estimated from submittal to the agencies and assumes that 60 percent drawings are used for developing the application. ** It is our understanding that the City is considering this project exempt from the City's code. * * * State Environmental Policy Act (SEPA) checklist must be approved before HPA can be approved. City = City of SeaTac Corps = U.S. Army Corps of Engineers Ecology = Washington State Department of Ecology HPA = hydraulic project approval N/A = not applicable WDFW = Washington State Department of Fish and Wildlife 10.0 CLOSURE The findings and conclusions documented in this report have been prepared for specific application to this project, and have been developed in a manner consistent with that level of care and skill normally exercised by members of the environmental science profession currently practicing under similar conditions in the area, and in accordance with the terms and conditions set forth in our agreement. The conclusions and recommendations presented in this report are professional opinions based on interpretation of information currently available to us, and are 21 -1 -12258 -001 -R l f.doc /wp/FR W RK 18 21 -1 -12258 -001 SHANNON &WILSON, INC. made within the operational scope, budget, and schedule constraints of this project. No warranty, express or implied, is made. Shannon & Wilson, Inc. has prepared the Appendix, "Important Information About Your Wetland Delineation/Mitigation and /or Stream Classification Report," to assist you and others in understanding the use and limitations of our reports. SHANNON & WILSON, INC. atie L. Walter, P.W.S. Per Natural Resources Manager Biologist Senior Associate PCJ:KLW /pcj 21- I- 12258- 00I- RIfdoc'wrEET RECFJ : M 2 8 2309 19 IDESSLO $? d,it 21-1-12258-001 11.0 REFERENCES Brinson, M.M., 1993, A hydrogeomorphic classification for wetlands: U.S. Army Corps of Engineers Waterways Experiment Station, Wetlands Research Program Technical Report WRP -DE -4. City of SeaTac, 2007, City of SeaTac comprehensive plan, Map 8.1, wetland and stream classification: SeaTac, Wash., City of SeaTac. City of SeaTac, updated December 2007, City of SeaTac municipal code, environmentally sensitive areas section (chapter 15.30): SeaTac, Wash., City of SeaTac. Cowardin, L.M., and others, 1979, Classifications of wetlands and deepwater habitats of the United States: U.S. Fish and Wildlife Service Publication FWS /OSB- 79/31. Dodge, Jack, Principal Planner, City of SeaTac, 2008, Personal communication between Jack Dodge, City of SeaTac, and Per Johnson, Shannon & Wilson, Inc., regarding internal City meeting minutes and applicability of SMC 15.30.050(C)4 to the Project: June 18. ESA Adolfson, 2007, City of Tukwila shoreline master plan update, shoreline inventory and characterization report, City of Tukwila, Washington. Habitat Technologies, 2001, Wetland and drainage corridor evaluation and delineation report, Preston parcel short plat, City of SeaTac, Washington: Habitat Technologies. Hitchcock, C.L., and Cronquist, A., 1973, Flora of the Pacific Northwest: Seattle, Wash., University of Washington Press. Karuna Environmental Services, 2002, Preston short plat wetland delineation addendum, City of SeaTac, Washington: Karuna Environmental Services. Larson, Ryan, 2008, Personal communication between Ryan Larson, Senior Surface Water Management Engineer, City of Tukwila, and Per Johnson, Biologist, Shannon & Wilson, Inc., regarding the downstream flow path of surface water from stream 1 and potential stream 3 once crossing under interstate 5: June 11. Munsell® Color, 1992, Munsell soil color charts: Newburgh, NY, Macbeth Division of Kollmorgen Instruments Corporation. PAC -TECH Engineers, 1991, Wetland analysis for Norris Property, City of SeaTac, Washington: PAC -TECH Engineers. 21 -1- 12258 -001 -R 1 f.doc/wp/FRW RK 20 21 -1 -12258 -001 Reed, Porter B., Jr., 1993, 1988, National list of plant species that occur in wetlands: Northwest (Region 9), Biological Report 88 (26.9). U.S. Army Corps of Engineers (Corps), 1987, Corps of Engineers wetlands delineation manual: Vicksburg, Miss., U.S. Army Corps of Engineers Waterways Experiment Station, Technical Report Y-87-1. U.S. Department of Agriculture (USDA), 2001, Hydric soils list, King County area, Washington: Detailed soil map legend: U.S. Department of Agriculture. Washington State Department of Ecology, 1997, Washington State wetlands identification and delineation manual: Olympia, Wash., Washington State Department of Ecology, Publication #96 -94. Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District, and U.S. Environmental Protection Agency Region 10, 2006, Wetland mitigation in Washington State — Part 1: Agency policies and guidance (version 1): Olympia, Wash., Washington State Department of Ecology, Publication no. 06-06-011a, March. Washington State Department of Ecology, U.S. Army Corps of Engineers Seattle District, and U.S. Environmental Protection Agency Region 10, 2006, Wetland mitigation in Washington State — Part 2: Developing mitigation plans (version 1): Olympia, Wash., Washington State Department of Ecology, Publication no. 06-06-011b, March. 21-1-12258-001-RI fdoc /wp /FR W RK 21 21 -1- 12258 -001 Filename: J:\211\12258-001\21-1-12258-001 flg 6.dwg Date: 06-19 -2008 Login: mm Approximate Location of Proposed Alternative Alignments Not to Scale LEGEND lip Lake Stream Classifications Class 2 Stream- Perennial; Salmonid Use Undetermined (50' Buffer) �.� Class 2 Stream. Perennial; No Salmonids (50' Buffer) Class 3 Stream- Intermittent (25' Buffer) Unclassified Stream (Buffer to be Determined) Wetland Classification W.)4. Class 1 Wetland (100' Buffer) Class 2 Wetland (50' Buffer) Class 3 Wetland (35' Buffer) Unclassified (Buffer to bltgetrriNcr) Alternatives 1 & 2 Alternative 3 nn 28 2233 '�iJFtiTY OM 'T NOTE Figure adapted from the City of SeaTac Comprehensive Plan Map 8.1 (Wetland & Stream Classifications, dated 9/4/07 (Revised 8/07). Sunrise View Stormwater Bypass Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington SEATAC WETLANDS AND STREAMS MAP June 2008 21 -1- 12258 -001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 6 t v' ,.., 'r`t UNTO ---"m"Ilil ; Washington ltrBattle ili, Project Location asrER . � 9y ■ Y 138 1� -- � ` 31, �>ry- C�N-yrCy�y3 , �' , g 3 ,7t NIS��� r'' �`,;, " tf �;� ' �� v T : ' > ua "Ae i stfi i =J♦at ` i "' 1457}1 s oo ST s i sT i '< SI S 147L: Tx INZfthtlT LIB 48 4200 ST E' s i. � 22 15 h Soul 4200 "' CtL . . Ij < ? N� � t ® ISIST ST _ � i7 } ST 14' S 149TH h 4 �j$y�� s i snt 1 n 2 155 ST 1 5 1521q PL 1 s 151 S'ff 518 S1 ". r 158TH OM 4 j lF orsi `� r l ® r.r E v. � 4v . Iii' b f , ] •x 1' aa, ST i . i tw 1. g1x s 5 . 161ST ,4 ST _, j If N£STFI£ID SQ/rNCEM£R MIMI p, 3 i sr stElllt4 _ 167TH ST 164Th ST e 9 STRANDERal Pro i H S 168 6 PROJECT c=' c, TWOIILA MD 26 CORPOAA7 OR N LOCATION gi5 S MST sr 1721A N$ 73RD 7. 3 ST ST 5100 41111116 1 a / S 172ND '< v' E �° ST 17 i CORPORA u 20NINKLER OR S $ .4 _ 176TH 5 yr 4300 S 178TH ST u f e"' > .,ue ^o-r ; gO�'t` _. t to 178TH i NI . TRI u 1. ,. t s'/ • /TIC i'Jaiir II 0 11111111lik KaR©M I 111111I111BORML. . Tripp wro.I 1/4 1 Rpr. irk Sunrise View Stormwater Bypass I " . "��` -� Scale in Miles r,.,4 0 c^ a -. ,,e, - . e e Ed L� .,, j Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington GO, AUNtTr NOTE DEVELOPIJENT Reproduced with permission granted by THOMAS BROS. MAPS ®. This map is copyrighted by © Rand McNally, R.L. 08 -S-34. It is unlawful to copy or reproduce all or any part thereof, whether for All VICINITY MAP June 2008 21 -1- 12258 -001 personal use or resale, without permission. rights reserved. SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 1 Filename: J:\211 \12258 - 001\21 -1- 12258-001 flg 2.dwg c , w� ,r. All Alternatives Connect Existing System 170TH vins Now a) ma fit *aka; lid iirst s fisge-A so' ,.5-3 . mo I 4 172ND ST Alternative 1 Pump Station j Alternative 1 (Forcemain) Alternative 2 (Pipe Tunnel) c = 0 LEGEND 172ND 300 600 Scale in Feet ■ IN IN I. Alternatives 1& 2 c) Alternative 3 F In Sunrise View Stormwater Bypass Pipeline Alternatives Analysis t c �. Wetland and Stream Reconnaissance e • SeaTac, Washington COMMUN1 Y DEVELOPL.:1 _;di PROPOSED ALTERNATIVES MAP NOTE Figure adapted from file Sunrise View Figure 3.pdf received from PACE Engineers on 04/25/2008. June 2008 21- 1- 12258-001 SHANNON & WILSON, INC. FIG. 2 Geotechni al and Environmental Consultants Filename: J:\211 \12258. 001\21 -1- 12258-001 fig 3.dwg Date: 06-19 -2008 Login: mm ?CO ss4 o 00 5 1_) S 00 5«x Me. 00 N :0 `5549 = O 50 :0 O 250 5]0 • Natatal Resources Conservation Service w MO <0 z ra'a -d i I I-1 I I Approximate Scale in Feet s i NOTE Figure adapted from the US Department of Agriculture (USDAs) Natural Resource Conservation Service (NRCS) Web Soil Survey (WSS) mapping system, accessed on 6 -2 -08. i0c Qyle:a i 3 :0 Feet t _ :0 Web Soil S rverr 2.0 National Cooperative Sod Survey 500 1000 555.200 7) 61212008 Page 1 of 3 LEGEND Alternatives 1 8 2 ElmatEgme Alternative 3 AmC Arents, Alderwood Materia, 6 to 15% Slopes AkF Alderwood and Kitsap Soils, very steep Ur Urban Land Sunrise View Stormwater Bypass Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington USDA SOILS MAP June 2008 21 -1- 12258 -001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 3 C Ir Tr Filename: J:\211 \12258. 001\21 -1- 12258-001 fig 4.dwg Date: 06-19 -2008 Login: mm J rr —I aC C ) C << i 1. LEGEND PUBHA = Palustrine, Unconsolidated Bottom, Permanently Flooded, Excavated PEMA = Palustrine, Emergent, Temporarily Flooded PEMC = Palustrine, Emergent, Seasonally Flooded R2UBH = Riverine, Lower Perennial, Unconsolidated Bottom, Permanently Flooded PSS /FOC = Palustrine Scrub Shrub/Forested, Seasonally Flooded PABH = Palustrine, Aquatic Bed, Permanently Flooded Alternatives 1 & 2 ❑❑❑❑❑oaa Alternative 3 NOTE Figure adapted from the US Fish and Wildlife Service (USFWS) National Wetland Inventory (NWI) wetlands mapper mapping system, accessed on 6 -2 -08. Not to Scale Sunrise View Stormwater Bypass Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington USFWS NWI MAP June 2008 - 21 -1- 12258 -001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 4 Sunrise View NWI Map , i....�;;- ..n' 122.1730w 122.17 -0w 122.1830w 122•+8-0w l22.1830w A • 9 = 4z - I 102/•I FJ I -.'''`'• \--- --` '- a N z _ x �N Legend Ai Worsts!, MRaub r ROa - Cana Road A+ Rood* • alias f . Loos Quad blind Efnnaraw Aral *Wm OMpNb1 ** 6hebe ate mean pawn • iinstepeK Eartgast Wang* a = Lana omrr .� alnnvr Loam 411 Available Weiland Data Nen0apai DOM „+ NND Stream p Comdlae WOK p saw goat a South America pNora America Eta ( �I ` Approximate Location of Proposed Alternative Alignments = 'tea ' ' �Fi$Ili. +w "1 111 r 1 �����r- eRCaaR�Ie�IZ111AN IRI1�� 1111111111P4 f .4� III 1. W a s h .: ton7 > ,., • �� / ��l PABH ` M' �� e,` —�w ,� � :� - 1 OM MIN - PSS/F �, 1 v Irf>+7t -' :~ —` � � 1. n. a:t. al. , •� M. n J. R BM C l� fi` MIN 1- =Ille 76 11:2 1730 W 122.17.0 W 122.1830 W 122.16.0 W 122.1540 W z Map center: 4r 26' sr N. 12r 18' 1r w 7hla map Is. .351 generated untie output horn anInternet mooing We and Is for general . HMe AP S OT 0 E UmSEm R NAm VOeAe71 NWae. eu ne d. dr e lemi LEGEND PUBHA = Palustrine, Unconsolidated Bottom, Permanently Flooded, Excavated PEMA = Palustrine, Emergent, Temporarily Flooded PEMC = Palustrine, Emergent, Seasonally Flooded R2UBH = Riverine, Lower Perennial, Unconsolidated Bottom, Permanently Flooded PSS /FOC = Palustrine Scrub Shrub/Forested, Seasonally Flooded PABH = Palustrine, Aquatic Bed, Permanently Flooded Alternatives 1 & 2 ❑❑❑❑❑oaa Alternative 3 NOTE Figure adapted from the US Fish and Wildlife Service (USFWS) National Wetland Inventory (NWI) wetlands mapper mapping system, accessed on 6 -2 -08. Not to Scale Sunrise View Stormwater Bypass Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington USFWS NWI MAP June 2008 - 21 -1- 12258 -001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 4 Filename: J :\211 \12258. 001\21 -1- 12258-001 fig 5.dwg Date: 06-19 -2008 Login: mm ".iK ■ MEI II 11= Mai Approximate Location of I Proposed Alternative Alignments l . "VI' Bit i tcts'4c \ p H 11: OHM n I ' i.. .,— <�'i2 b J� •• • r "n(. .a• _ rot i ,rW,5sa c >rJG',(•:u'7�W.. fir NOTE ,,•" Figure adapted from information provided by King County iMap Geographical Information System (GIS) mapping system, accessed on 6 -2 -08. N LEGEND Wildlife Network SAO Stream Cbs3'1 Class 2 P menial Class 2 Sabstu id Class 3 Unclassified Lakes and Large Rivers Streams so Ns NE •• s• Alternatives 1& 2 _ip Alternative 3 0 600 1200 I I Approximate Scale in Feet Sunrise View Stormwater Bypass Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington KING COUNTY IMAP June 2008 21 -1 -12258 -001 SHANNON & WILSON, INC. FIG. 5 Geotechnical and Environmental Consultants E E Date: 06-19 -2008 Filename: J:\211 \12258 -001\21 -1- 12258 -001 fig 7.dwg NOTES 1. Wetland and stream buffers are not shown. Buffers are regulated by the City of SeaTac and Tukwila. It is our understanding that the City of SeaTac will consider the project exempt from Section 15.30.050(C)4 of the SeaTac Municipal Code. It is also our understanding that the project will not impact any wetlands, watercourses, or associated buffers within the City of Tukwila. 2. Figure adapted from file 12841680.TIF received from City of SeaTac on 6/6/2008 and drawing file 8626- SRV.dwg received from Pace Engineers on 04/25/2008. 0 200 400 Approximate Scale in Feet LEGEND 111 I] El El Q Alternatives 1 & 2 Alternative 3 Approximate Location of Stream /Ditch Approximate Location of Wetland COMMiJNIT DE%ELOpEEt . Sunrise View Stormwater Bypass Pipeline Alternatives Analysis Wetland and Stream Reconnaissance SeaTac, Washington WETLAND AND STREAM RECONNAISSANCE MAP June 2008 21 -1- 12258 -001 SHANNON & WILSON, INC. Geotechnical and Environmental Consultants FIG. 7 APPENDIX IMPORTANT INFORMATION ABOUT YOUR WETLAND DELINEATION/MITIGATION AND /OR STREAM CLASSIFICATION REPORT 21 -1 -12258 -001 = I llSHANNON & WILSON, INC. Geotechnical and Environmental Consultants Attachment to and part of Report 21 -1- 12258 -001 Date: June 19, 2008 To Ms. Chris Rhinehart, P.E. PACE Engineers, Inc. IMPORTANT INFORMATION ABOUT YOUR WETLAND DELINEATION /MITIGATION AND /OR STREAM CLASSIFICATION REPORT A WETLAND /STREAM REPORT IS BASED ON PROJECT - SPECIFIC FACTORS. Wetland delineation/mitigation and stream classification reports are based on a unique set of project - specific factors. These typically include the general nature of the project and property involved, its size, and its configuration; historical use and practice; the location of the project on the site and its orientation; and the level of additional risk the client assumed by virtue of limitations imposed upon the exploratory program. The jurisdiction of any particular wetland /stream is determined by the regulatory authority(s) issuing the permit(s). As a result, one or more agencies will have jurisdiction over a particular wetland or stream with sometimes confusing regulations. It is necessary to involve a consultant who understands which agency(s) has jurisdiction over a particular wetland/stream and what the agency(s) permitting requirements are for that wetland/stream. To help reduce or avoid potential costly problems, have the consultant determine how any factors or regulations (which can change subsequent to the report) may affect the recommendations. Unless your consultant indicates otherwise, your report should not be used: ► If the size or configuration of the proposed project is altered. ► If the location or orientation of the proposed project is modified. ► If there is a change of ownership. ► For application to an adjacent site. ► For construction at an adjacent site or on site. ► Following floods, earthquakes, or other acts of nature. Wetland /stream consultants cannot accept responsibility for problems that may develop if they are not consulted after factors considered in their reports have changed. Therefore, it is incumbent upon you to notify your consultant of any factors that may have changed prior to submission of our final report. Wetland boundaries identified and stream classifications made by Shannon & Wilson are considered preliminary until validated by the U.S. Army.Corps of Engineers (Corps) and /or the local jurisdictional agency. Validation by the regulating agency(s) provides a certification, usually written, that the wetland boundaries verified are the boundaries that will be regulated by the agency(s) until a specified date, or until the regulations are modified, and that the stream has been properly classified. Only the regulating agency(s) can provide this certification. MOST WETLAND /STREAM "FINDINGS" ARE PROFESSIONAL ESTIMATES. Site exploration identifies wetland/stream conditions at only those points where samples are taken and when they are taken, but the physical means of obtaining data preclude the determination of precise conditions. Consequently, the information obtained is intended to be sufficiently accurate for design, but is subject to interpretation. Additionally, data derived through sampling and subsequent laboratory testing are extrapolated by the consultant who then renders an opinion about overall conditions, the likely reaction to proposed construction activity, and/or appropriate design. Even under optimal circumstances, actual conditions may differ from those thought to exist because no consultant, no matter how qualified, and no exploration program, no matter how comprehensive, can reveal what is hidden by earth, rock, and time. Nothing can be done to prevent the unanticipated, but steps can be taken to help reduce their impacts. For this reason, most experienced owners retain their consultants through the construction or wetland mitigation /stream classification stage to identify variances, to conduct additional evaluations that may be needed, and to recommend solutions to problems encountered on site. Page 1 of 2 1/2008 WETLAND /STREAM CONDITIONS CAN CHANGE. Since natural systems are dynamic systems affected by both natural processes and human activities, changes in wetland boundaries and stream conditions may be expected. Therefore, delineated wetland boundaries and stream classifications cannot remain valid for an indefinite period of time. The Corps typically recognizes the validity of wetland delineations for a period of five years after completion. Some city and county agencies recognize the validity of wetland delineations for a period of two years. If a period of years have passed since the wetland /stream report was completed, the owner is advised to have the consultant reexamine the wetland /stream to determine if the classification is still accurate. Construction operations at or adjacent to the site and natural events such as floods, earthquakes, or water fluctuations may also affect conditions and, thus, the continuing adequacy of the wetland /stream report. The consultant should be kept apprised of any such events and should be consulted to determine if additional evaluation is necessary. THE WETLAND /STREAM REPORT IS SUBJECT TO MISINTERPRETATION. Costly problems can occur when plans are developed based on misinterpretation of a wetland /stream report. To help avoid these problems, the consultant should be retained to work with other appropriate professionals to explain relevant wetland, stream, geological, and other findings, and to review the adequacy of plans and specifications relative to these issues. DATA FORMS SHOULD NOT BE SEPARATED FROM THE REPORT. Final data forms are developed by the consultant based on interpretation of field sheets (assembled by site personnel) and laboratory evaluation of field samples. Only final data forms customarily are included in a report. These data forms should not, under any circumstances, be drawn for inclusion in other drawings because drafters may commit errors or omissions in the transfer process. Although photographic reproduction eliminates this problem, it does nothing to reduce the possibility of misinterpreting the forms. When this occurs, delays, disputes, and unanticipated costs are frequently the result. To reduce the likelihood of data form misinterpretation, contractors, engineers, and planners should be given ready access to the complete report. Those who do not provide such access may proceed under the mistaken impression that simply disclaiming responsibility for the accuracy of information always insulates them from attendant liability. Providing the best available information to contractors, engineers, and planners helps prevent costly problems and the adversarial attitudes that aggravate them to a disproportionate scale. READ RESPONSIBILITY CLAUSES CLOSELY. Because a wetland delineation /stream classification is based extensively on judgment and opinion, it is far less exact than other design disciplines. This situation has resulted in wholly unwarranted claims being lodged against consultants. To help prevent this problem, consultants have developed a number of clauses for use in written transmittals. These are not exculpatory clauses designed to foist the consultant's liabilities onto someone else; rather, they are definitive clauses that identify where the consultant's responsibilities begin and end. Their use helps all parties involved recognize their individual responsibilities and take appropriate action. Some of these definitive clauses are likely to appear in your report, and you are encouraged to read them closely. Your consultant will be pleased to give full and frank answers to your questions. THERE MAY BE OTHER STEPS YOU CAN TAKE TO REDUCE RISK. Your consultant will be pleased to discuss other techniques or designs that can be employed to mitigate the risk of delays and to provide a variety of alternatives that may be beneficial to your project. Contact your consultant for further information. Page 2 of 2 1/2008 CITY OF TUKWILA Department of Community Development 6300 Southcenter Boulevard, Tukwila, WA 98188 Telephone: (206) 431 -3670 FAX (206) 431 -3665 E -mail: tukplannci.tukwila.wa.us REcalvEn SPECIAL I� �P. RMISSION pJU COMMUNITY IRECTOR DEVELOPI ENT APPLICATION FOR STAFF USE ONLY Permits Plus Type: P -SP Planner: File Number: f3 01 - 0 3 0 Application Complete (Date: ) Project File Number: Application Incomplete (Date: ) Other File Numbers: NAME OF PROJECT/DEVELOPMENT: nl ( l l S t V It l4 f�r�A riP4onl LOCATION OF PROJECT/DEVELOPMENT: Give street address or, if vacant, indicate lot(s), block and subdivision, access street, and nearest intersection. Wrat-14 WS DST (EIE,Ir^oF- PAY/ ,ft M ,T To Oa, (//04.1 sO Jf4 p r4/ s Ttat �T 5 17o t $;r LIST ALL TAX LOT NUMBERS (this information may be found on your tax statement). DEVELOPMENT COORDINATOR : The individual who: • has decision making authority on behalf of the owner /applicant in meetings with City staff, • has full responsibility for identifying and satisfying all relevant and sometimes overlapping development standards, and • is the primary contact with the City to whom all notices and reports will be sent. Name: Address: Phone: E -mail: FLoQ -En1 D7 CAS UDM -/ •��. 4100 S / $gam Ste/ -• AG e7 #441 -- S4%/� OA- . 7c/ s8' 206. 97i. 4-740 FAX: 1496 , .773 .4-8•0? ' c h o w ] I p G; . se.a Me . wa . u Signature: Date: G / /7 / Zoe) q Check items submitted with application --i Information Required. May be waived in unusual cases, upon approval of both Public Works and Planning Vicinity map showing location and names of adjacent roads; Property lines; Locations of all buildings on site; Dimensioned elevations of building drawn to scale (for wall signs); Elevations, dimensions and materials of proposed sign(s) including advertising copy; Color elevation of proposed sign. CARGO CONTAINER APPROVAL 12. Site plan showing the location of the container(s) in relationship to parking areas, property lines, buildings, streets, trails, landscape areas and setbacks. 13. Description of the proposed screening. 14. Dimensions of proposed cargo container. SINGLE - FAMILY DESIGN STANDARD EXCEPTIONS 15. Dimensioned and scalable building elevations with keyed colors and materials. 16. The site plan must include a graphic scale, north arrow, proposed house footprint, any existing structures, lot lines, setbacks, adjacent streets, driveways, parking areas, any sensitive areas and any fences, rockeries or retaining walls. P: \P08 \08828 SEATAC Sunrise View \ CAD \ Shoots \P08628CDV.dwg CITY. 7..23 IL, R 4 E, SJL SEATAC Project No. SD -062 VICINITY MAP SEATAC CITY COUNCIL MAYOR: DEPUTY MAYOR: COUNCIL MEMBERS: NORTH RALPH SHAPE GENE FISHER MIA GREGERSON TERRY. ANDERSON CHRIS WYTHE TONY. ANDERSON BARRY LADENBURG INDEX TO. DRAWINGS. G.101 G1.02 C1.00 C1.01 C1.02 C1.03 C1.04 C2.00 C2.01 C2.02 C2.03 C2.04� C3.01 C3.02 C3.03 C3.04 COVER SHEET PROJECT KEY PLAN, LEGEND, GENERAL NOTES EXISTING CONDITIONS TESC PLAN TESC NOTES AND ' DETAILS TESC NOTES AND DETAILS TESC NOTES AND DETAILS ' STORMWATER SITE PLAN S 170TH LANE DRAINAGE PLAN 'AND PROFILE S. 170TH LANE DRAINAGE PLAN AND _ PROFILE 53RD AVE S DRAINAGE PLAN AND PROFILE 53RD AVE S DRAINAGE PLAN AND PROFILE STORM DRAINAGE DETAILS STORM DRAINAGE DETAILS STORM DRAINAGE DETAILS RESTORATION DETAILS These plans have been reviewed by the Public • Works Department for- amformance with current City standards. Accepanee is subject to errors and omissions which do not =hods violations of adopted standards or ordinmm. The responsibility for the adequacy of the design rests totally with the designs. Addition,, deletions or revisions to these drawings after this date will void this accepnn,e and will require a resabmiaal of revised drawing for subcgueat approval . . Final mem= is mbjea to Held mien by .. the Public Works utilities inspector. 4./g /o C • U$6 Pnvi,JG e E,454,„,,,„_ 9roxi jo/, - o^' L'f ) NO. DATE BY APPR. REVISION ttotmaa,...a.wao 0.>9aA1L1JBl6�aA47Mt taalasedmipaseaole . ws .ewms..r04e • wow= • DRN. LG IDSGN. MM I CHKD. EN Public Works Department Torn Gut, P.E., Public Works Director Susan Sanderson, P.E, City Engineer 4800 South 188th Street SeaToc, So 98198 -8905 Telephone: (208) 973 -4730. Engkreerhq Division RECEIVED APR 23 2008 ��+canui WORKS 09-037 Call before you Dig• 1- 800 - 424 -5555 uasrmtaao SOME (tall 90% SUBMITTAL CITY OF SEATAC SUNRISE VIEW' BYPASS PIPELINE COVER SHEET DATE: 03/31/09. 1JOB # SD -082 I SCALE: AS SHOWN SHEET NO: G1.01 OF X C.: - It is LI,ivL. =t y.r VALLE.i VIEW Feet HEWER DISTRICT le Fee l F . ' 8125200340 IE 18••CONC. =229 46 IE. 18 "CMP 2226:12 ASPHALT /: WETLAND D w m DP -1 ECOLOGY BLOCK•WALL D -4 FLATTEN CHANNEL SIDE SLOPES TO MATCH WETLAND EDGE HEI(E. DO NOT DS1URB WETLAND( ., •IE 18 "CPfP= 220.84 • IE 6 °PVC (CAPF+ED= 221.20 -5. o c CV N 2'2 -= SS kIM= *26.19 Cl/'CHNk (N.SW)= 216.74 8 "CiAP =?,4 9.89 DREND Das u o it oNP �f�VC= 119.83 9• PVC AS NEEDED It? HANNa K WALL 87C. W. 36' HOPE 45' BEND. BUTT FUSED IE 221.80 $••C. W. . ' EA991ENT : LAST (S) i1$. C. W, / 3 6,ALDER$ �1°wsuLr PEE ., NORTH OUTFALL PARTIAL PLAN SCALE 1•- 1O• -O' 02,03 8' DIA. WET WELL ABAt (CUT OFF AND FULL Of WOVEN GEOIEXTILE LINER PER WSDOT 9-33 TABLE 3. NON. GRAB TEN9LE STRENGTH 315 LB. SD,MH P.IM�176.57 2?CMP(W)= 164.97,,': i IE ++4:'CMP()= 155.92 GABION MATTRESS DIMPATDR EXTEND SLEEVE TO 4' OVER 1l8 HDPE (MW). 1NE /19AiE 18' HOPE IS 1r CLEAR • BEND ANq.E - EIaSTBNG- GROUND THRUST BLOCK PLACE WOVEN CEO1EXTUE LINER PER 1900T.9 -33 TABLE 3 MIN. GRAB TENSILE STRENGTH 3151B BELOW GABIONS AT Soo BEDDING • Public Works Department Tom Gut, P.E, Public Works Director Susan Sanderson, P.E. City Engineer 90% SUBMITTAL • • CITY OF SEATAC • SUNRISE VIEW •IBYPASS PIPELINE STORM DRAINAGE DETAILS DATE: 03/31/09 1 JOB N SD -082 I SCALE: AS SHOWN