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HomeMy WebLinkAboutSEPA E06-013 - HIRAI GEORGE - CITYVIEW ESTATES (5 SINGLE FAMILY HOMES)CITY VIEW ESTATES NW Corner of TIB and S 132 AV S 13041 TIB E06 -013 • City of Tukwila • Department of Community Development / 6300 Southcenter BI, Suite 100 / Tukwila, WA 98188 / (206)431 -3670 File Number: Applied: Issue Date: Status: DETERMINATION OF NON - SIGNIFICANCE (DNS) E06 -013 07/03/2006 08/30/2006 APPROVED Applicant: GEORGE K. HIRAI Lead Agency: City of Tukwila Description of Proposal: George F. Hirai has proposed to construct five (5) single family homes on five existing Tots at the Northwest corner of Tukwila International Blvd (TIB) and S. 132nd Avenue South. Access to the lots will be via a public alley way which will connect to S. 132nd Avenue South. The project will require a cut/fill of approximately 800 cubic yards. Grading work on the property is needed for the installation of drainage facilities, grading of the alley way, and site preparation for the houses. Location of Proposal: Address: Parcel Number: Section/Township /Range: 13041 TUKWILA INTERNATIONAL BL TUKW The City has determined that the proposal does not have a probable significant adverse impact on the environment. An environmental impact statement (EIS) is not required under RCW 43.21c.030(2) (c). 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. This DNS is issued under WAC 197 -11- 340(2). Comments must be submitted by The lead agency will not act on this proposal for 14 days from the date below. Steve Lancaster, Responsible Official City of Tukwila 6300 Southcenter Blvd Tukwila, WA 98188 (206)431 -3670 -3O- 0(0 Date Any appeal shall be linked to a specific governmental action. The State Environmental Policy Act is not intended to create a cause of action unrelated to a specific governmental action. Appeals of environmental determinations shall be commenced within the time period to appeal the governmental action that is subject to environmental review. (RCW 43.21C.075) doc: DNS E06 -013 Printed: 08 -28 -2006 Dept. Of Community Development City of Tukwila AFFIDAVIT OF DISTRIBUTION I ,gyp �n _�p HEREBY DECLAR THAT: Notice of Public Hearing � �/ v / D Determination of Non - Significance Notice of Public Meeting. M Mitigated Determination of Non- Significance Board of Adjustment Agenda Pkt D Determination of Significance & Scoping Notice Board of Appeals Agenda Pkt N Notice of Action Planning Commission Agenda Pkt O Official Notice Short Subdivision Agenda N Notice of Application Shoreline Mgmt Permit N Notice of Application for Shoreline Mgmt Permit __ F FAX To Seattle Times O Other Was mailed to each of the addresses listed on this 3 year 2004? (I) 1 ii,(� -' Project Number: C� JJ((Q '' D t 3 Mailer's Signature: - (4,444,/ - g4,0�/ Person requesting mailing: P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM • FEDERAL AGENCIES ( ) U.S. ARMY CORPS OF ENGINEERS ( ) FEDERAL HIGHWAY ADMINISTRATION ( ) DEPT OF FISH & WILDLIFE () U.S. ENVIROIv'IGIENTAL PROTECTION AGENCY () U.S. DEPT OF H.U.D. () NATIONAL MARINE FISHERIES SERVICE WASHINGTON STATE AGENCIES () DEPT OF SOCIAL & HEALTH SERV. ( ) DEPT OF ECOLOGY, SHORELAND DIV ■DEPT OF ECOLOGY, SEPA DIVISION' ( )'OFFICE OF ATTORNEY GENERAL CHKLIST W/ DETERMINATIONS SITE MAPS WITH DECISION ( ) OFFICE OF ARCHAEOLOGY ( ) TRANSPORTATION DEPARTMENT () DEPT NATURAL RESOURCES ( ) OFFICE OF THE GOVERNOR ( ) DEPT OF COMM. TRADE & ECONOMIC DEV. () DEPT OF FISHERIES & WILDLIFE « KING COUNTY AGENCIES • SEND • SEND () BOUNDARY REVIEW BOARD () FIRE DISTRICT #11 () FIRE DISTRICT #2 ( ) K.C. WASTEWATER TREATMENT DIVISION () K.C. DEPT OF PARKS & REC () K.C. ASSESSOR'S OFFICE ( ) TUKWILA SCHOOL. DISTRICT ( ) TUKWILA LIBRARY () RENTON LIBRARY () KENT LIBRARY () CITY OF SEATTLE LIBRARY ( ) OWEST ( ) SEATTLE CITY LIGHT () PUGET SOUND ENERGY () HIGHLNE WATER DISTRICT () SEATTLE WATER DEPARTMENT ( ) AT &T CABLE SERVICES SCHOOLS/LIBRARIES UTILITIES CITY AGENCIES ( ) KENT PLANNING DEFT ( ) TUKWILA CITY DEPARTMENTS: () PUBLIC WORKS () FIRE () POLICE () FINANCE () PLANNING () BUILDING () PARKS & REC. () MAYOR () CITY CLERK OTHER ( ) PUGET SOUND REGIONAL COUNCIL ( ) SW K C CHAMBER OF COMMERCE ( ) MUCKLESHOOT INDIAN TRIBE ( ) CULTURAL RESOURCES PROGRAM ( ) FISHERIES PROGRAM ( ) WILDLIFE PROGRAM ( ) SEATTLE TIMES () SOUTH COUNTY JOURNAL P:\ADMINISTRATIV E \FORMS \CHKLIST.DOC ( ) HEALTH DEPT () PORT OF SEATTLE ( ) KC. DEV & ENV1R SERVICES -SEPA INFO CNTR ( ) K.C. TRANSIT DIVISION - SEPA OFFICIAL () K.C. LAND & WATER RESOURCES () FOSTER LIBRARY () K C PUBLIC LIBRARY ( ) HIGHLINE SCHOOL DISTRICT ( ) SEATTLE SCHOOL DISTRICT ( ) RENTON SCHOOL DISTRICT ( ) OLYMPIC PIPELINE ( ) VAL -VUE SEWER DISTRICT ( ) WATER DISTRICT #20 () WATER DISTRICT #125 ( ) CITY OF RENTON PUBLIC WORKS () BRYN MAWR- LAKERIDGE SEWER/WATER DISTRICT () RENTON PLANNING DEPT () CITY OF SEA -TAC () CITY OF BURIEN ( ) TUKWILA PLANNING COMMISSION MEMBERS ( ) TUKWILA CITY COUNCIL MEMBERS () CITY OF SEATTLE - SEPA INFO CENTER - DCLU () STRATEGIC PLANNING OFFICE' • NOTICE OF ALL SEATTLE RELATED PLNG PROJ. LOCAL AGENCIES () DUWAMISH INDIAN TRIBE () P.S. AIR POLLUTION CLEAN AGENCY ( ) SOUND TRANSIT () DUWAMISH RIVER CLEAN -UP COAUTION 'SEND NOTICE OF ALL APPUCATIONS ON DUWAMISH RIVER MEDIA ( ) HIGHLINE TIMES ( ) CI.TUKWILA.WA.US.WWW POLIO NOTICE MAILINGS FOR PATS SEPA MAILINGS Mail to: (comment period starts on date of mailing) Dept. of Ecology Environmental Review Section 'Applicant 'Other agencies as necessary (checked off on attached list) Any parties of record send only the staff report, site plan and the SEPA Determination KC Transit Division — SEPA Official would like to receive information about all projects that might affect transit demand Send These Documents to DOE: SEPA Determination (3 -part from Sierra) Findings (staff report, usu. with MDNS) SEPA Checklist (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) Affidavit of Distribution (notice was mailed or sent to newspaper) SHORELINE MAILINGS:. Notice of Application for a Substantial Development Permit must be mailed to owners and to property owners within 500 feet of subject property, comments are due 30 days after the notice of application is mailed/posted. The notice of Application for Shoreline Substantial Development Permit must include a statement that any person desiring to submit written comments on the application or desiring to receive notification of the final decision on the application may do so within 30 days of the notice of application. If a hearing will be held on the application, the hearing notice must include the information that written comments may be submitted, or oral presentation made at the hearing. Shoreline Permit Notice of Decision: Mail to: (within 8 days of decision; 21 -day appeal period begins date received by DOE) Department of Ecology Shorelands Section State Attorney General . 'Applicant *Indian Tribes .. 'Other agencies as necessary (checked off on attached list). *Any parties of record send only the staff report, site plan and the SEPA Determination Send These Documents to DOE and Attorney General: Permit Data Sheet Shoreline Substantial Development Permit (3 -part from Sierra) Findings (staff report or memo) Shoreline Permit Application Form (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) - Site plan, with mean high water mark & improvements — Cross- sections of site with structures & shoreline - Grading Plan — Vicinity map SEPA determination (3 -part from Sierra) Findings (staff report or memo) SEPA Checklist (filled out by applicant) Any background studies related to impacts on shoreline Notice of Application Affidavit of Distribution (notice was mailed) P: W D M M1 STRATI V EIFORMSICIIICLI ST. DOC City of Tukwila Department of Community Development 6300 Southcenter Boulevard • Suite 100 Tukwila, WA 98188 -2599 George Hirai 15615 NE 62nd Court Redmond, WA 98052 To: From: Date: Re: MEMORANDUM Steve Lancaster Brandon Miles August 14, 2006 E06 -013 Earthwork for Cityview Estates NW Corner of Tukwila International Blvd and S. 132nd Avenue South Project Description: George F. Hirai has proposed to construct five (5) single family homes on five existing lots at the Northwest corner of Tukwila International Blvd (TIB) and S. 132nd Avenue South. Access to the lots will be via a public alley way which will connect to S. 132nd Avenue South. The project will require a cut/fill of approximately 800 cubic yards. Grading work on the property is needed for the installation of drainage facilities, grading of the alley way, and site preparation for the houses. Agencies with Jurisdiction: Department of Ecology (DOE) Other Required Permits: Land Altering/Grading /Preloads Permit Approval Building /Demolition Permits Plumbing/Mechanical Permits Electrical Permits Brandon Miles Page 1 Q: \SEPA \Cityview, E06- 013 \sepa - staffrpt.doc City of Tukwila, Public Works City of Tukwila, Community Development City of Tukwila, Community Development Washington State Dept. Labor and Industries or City of Tukwila, Community Development 08/28/2006 -� 'Brandon Miles E06 -013 SEPA Staff Report Summary of Primary Impacts: • Earth The City's sensitive area maps indicate that the property contains class two slopes. As required under the City's Sensitive Area regulations (TMC 18.45), the applicant submitted a geotechnical report prepared by Nelson Geotechnical Associates. The report is dated March 30, 2006. The site is currently undeveloped and is covered with grass, blackberries, and a few conifer and fruit trees. The sites slopes gently down toward the eastern property lines, where the slope then becomes moderate to steep over a vertical relief of less than ten feet. The slope is supported on the east property line by 3.5 foot to 8.0 foot high rockery retaining wall. The geotechnical reports notes that the soils in the area are mapped as Vashon till and deposits from the Pleistocene age. Approximately 400 cubic yards of fill will be removed from the site to accommodate the development. The Geotechnical report notes that there is a medium to high chance for erosion as result of this project. •Air Construction activities during construction may have some impact on air quality. The impacts may include dust particles and automobile exhausts. After the project is complete, additional traffic from the development will generate air impacts. Water There is no surface water body on or immediately adjacent to the property. The nearest water body would be the Duwamish River which is approximately four miles away. There are also no wetlands on or immediately adjacent to the property. The geotechnical report does note that it is likely that a perched water -table is present during winter months. • Plants The site consists of mix of grass, shrubs, and trees. Deciduous trees include maple, fruit trees and cottonwoods; evergreen trees consist of fir and cedar. Any trees removed on the steep slopes will require the issuance of a tree clearing permit. • Animals =' 'Brandon Miles E06 -013 SEPA Staff Report The animals on site are typical of those found in urban settings, such as birds and rodents. The property is bordered by residential development and the site is too small to provide habitat for any large species of mammals. The entire Puget Sound region is part of the Pacific Flyway for migrating birds. There are no known endangered or threatened species on the property. • Energy/Natural Resources During construction gasoline will be needed for operation of machinery and automobiles on the property. The project will have no affect on the potential for solar energy. • Environmental Health Noise from the project will be short term and will be associated with heavy construction equipment. The applicant will be required to meet the City's Noise Ordinance for work within residential districts of the City. The proposed homes may be impacted with noise from landings and takeoffs from King County Airport (Boeing Field). The City currently has no regulations requiring specific building modifications to homes in the King County Airport noise impact zone. Land /Shoreline Use The property is currently undeveloped land. There had been three houses on the property but those were demolished in 2005. The current zoning on the property is low density residential (LDR). The proposed use of the property is residential which is a permitted use in the LDR zone. Housing Five new homes will be constructed on the site. No persons will be displaced since the property is currently undeveloped. Aesthetics The applicant will retain as many trees as possible. This will help reduce any aesthetic impacts from the development. If the applicant should remove trees on the slope area, then replacement would be required under the City's tree protection ordinance. Light and Glare Lighting impacts will be minimal and will remain on site. Individuals who live on the property may be impacted by lighting on TIB. �•-)Eirandon Miles • E06 -013 SEPA Staff Report Recreation There are not parks or recreation areas within the immeidiate vicinity. Historic and Cultural Preservation No known places or landmarks exist within the project area. During construction if any landmarks or evident of historical, archaeological, scientific, or cultural importance are found on the site, work will stop immediately and the contractor will notify the City of Tukwila, Washington State Office of Archeology, and the Muckleshoot Indian Tribe. Transportation Additional traffic will be generated from the new homes once construction is complete. The traffic impacts will be minimal since these are proposed single family homes. Primary access to the homes is via a public alley. The alley connects to S. 132nd Street which connects to TIB. Public transit is available along TIB. The existing alley has been used by other homeowners in the area. The applicant is proposing to construct a retaining wall on the west side of the alley. This retaining wall may impact the use of this alley by the existing homes. All of the existing homes have a primary access and if access were denied from the alley the homes would still have legal access to a City street. The project will be subject to traffic impact fees at the time of building permit issuance. • Public Services Minor increase in the need for EMS, Fire, and Police services. • Utilities The project involves the extension of utilities to the various lots in the short plat. City Code requires that the utilities be underground. Recommendation: Determination of Non - Significance • City of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director NOTICE OF APPLICATION DATED August 2 „2006 The following applications have been submitted to the City of Tukwila Department of Community Development for review and decision. APPLICANT: AGENT: LOCATION: OWNER OF THE PROPERTY: FILE NUMBERS: PROPOSAL: OTHER INFORMATION: OTHER REQUIRED PERMITS: George K. Hirai George K. Hirai King County Parcel Numbers, 7359600653, 7359600654, 7359600655, 7359600669, and 7359600670 YOSHIKAWA TERRANCE E06 -013 The City has received a SEPA application to construct five new single family homes on the existing legal lots generally located NW of the intersection of S. 132rd Street and Tukwila International Blvd. Construction activities include grading, installation of utilities, and construction of drainage facilities, paving, and construction of five single family homes. The cut -fill on the entire project site does exceed 500 cubic yards. The applicant has submitted the following information for review, building plans, geotechnical review, and drainage analysis. Land Alternating, City of Tukwila Public Works Right of Way Permit, City of Tukwila Public Works Development Permits, City of Tukwila DCD Electrical Permits, Washington State Dept of Labor and Industries These files can be reviewed at the Department of Community Development, 6300 Southcenter Blvd., #100, Tukwila, WA. Please call (206) 431 -3670 to ensure that the file(s) will be available. 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 OPPORTUNITY FOR PUBLIC COMMENT You can submit comments on this application. You must submit your comments regarding the SEPA Application in writing to the Department of Community Development by 5:00 p.m. August 16, 2006. If you have questions about this proposal contact Brandon J. Miles, Planner -in- charge of this file at (206) 431 -3670 or bmiles @ci.tukwila.wa.us. Anyone who submits written comments will become parties of record and will be notified of any decision on this project. APPEALS You may request a copy of any decision by the City on a project or obtain information on your appeal rights by contacting the Department of Community Development at (206)- 431 -3670. DATE OF APPLICATION: NOTICE OF COMPLETE APPLICATION: NOTICE OF APPLICATION POSTED: July 3, 2006 July 13, 2006 August 2, 2006 • I.E. m.o. EA Rh • 197.3t I.E. 00 " E / 6 2. 2 4 ' — oHP TYPe - I OW 200 17.25 PO'S to \\ Combined Wet Veldt (Se• Oettd1Sht C5) 203.6 CO P 3, Type .11 Rim • 202.38 I.E. 197.3e (IN) \ I.E. • 190.08 (OUT) CPootete weft Ma. /ISA • N 205.8 8W 204.0 TW .207, BW key. ktfl4 CB It 2, Type I Rh, • 207.97 LE.. 202,97 N&S 5( „35 / c& /G EDGE OF ASPHALT \ STA: 1103.0 I I C.L. ortivete ROad FOGLI NE EOA OHP OHP 11314P SS \ S. .132ND _S I ea- h;91 \ • rs, 44- 0 . ss \ SS Dept. Of Community Development City of Tukwila . AFFIDAVIT OF DISTRIBUTION 1, I ) ./ c J REBY DECLARE THAT: Notice of Public Hearing Project Number: EOLL— 0(3 Determination of Non - Significance I , i>//2 Notice of Public .Meeting Person requesting mailing: Mitigated Determination of Non - Significance te Board of Adjustment Agenda Pkt Determination of Significance & Scoping Notice Board of Appeals Agenda Pkt Notice of Action Planning Commission Agenda Pkt Official Notice Short Subdivision Agenda Notice of Application Shoreline Mgmt Permit Notice of Application for Shoreline Mgmt Permit __ __ FAX To Seattle Times Classifieds Mail: Gail Muller Classifieds PO Box 70 - Seattle WA 98111 Other Was mailed to each of the addresses listed on this ocday of year 2006e_ . in the P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM • Project Name: . -1-ki .raA, K Project Number: EOLL— 0(3 Mailer's Signature: AllaAgok I , i>//2 Person requesting mailing: te dnL, P:GINAWYNETTA/FORMS /AFFIDAVIT -MAIL 08/29/003:31 PM • • FEDERAL AGENCIES ( ) U.S. ARMY CORPS OF ENGINEERS () FEDERAL HIGHWAY ADMINISTRATION ( ) DEPT OF FISH & WILDLIFE () U.S. ENVIRONMENTAL PROTECTION AGENCY () U.S. DEPT OF H.U.D. () NATIONAL MARINE FISHERIES SERVICE WASHINGTON STATE AGENCIES ( ) OFFICE OF ARCHAEOLOGY ( ) TRANSPORTATION DEPARTMENT () DEPT NATURAL RESOURCES () OFFICE OF THE GOVERNOR () DEPT OF COMM. TRADE & ECONOMIC () DEPT OF FISHERIES & WILDLIFE DEV. () DEPT OF SOCIAL & HEALTH SERV. () DEPT OF ECOLOGY, SHORELAND DIV DEPT OF ECOLOGY, SEPA DIVISION• ( ) OFFICE OF ATTORNEY GENERAL • SEND CHKLIST W/ DETERMINATIONS • SEND SITE MAPS WITH DECISION KING COUNTY AGENCIES () BOUNDARY REVIEW BOARD ( ) FIRE DISTRICT #11 ( ) FIRE DISTRICT #2 () K.C. WASTEWATER TREATMENT DIVISION () K.C. DEPT OF PARKS & REC. () KC. ASSESSORS OFFICE ( ) TUKWILA SCHOOL DISTRICT ( ) TUKWILA LIBRARY () RENTON UBRARY () KENT LIBRARY () CITY OF SEATTLE LIBRARY () QWEST ( ) SEATTLE CITY LIGHT () PUGET SOUND ENERGY ()HIGHUNE WATER DISTRICT () SEATTLE WATER DEPARTMENT ( ) AT&T CABLE SERVICES () KENT PLANNING DEPT ( ) TUKWILA CITY DEPARTMENTS: () PUBLIC WORKS () POLICE () PLANNING () PARKS & REC. () CITY CLERK SCHOOLS/LIBRARIES UTIUTIES CITY AGENCIES ( ) FIRE () FINANCE ( ) BUILDING ()MAYOR ( ) HEALTH DEPT () PORT OF SEATTLE () KC. DEV & ENVIR SERVICES -SEPA INFO CNTR ( ) K.C. TRANSIT DIVISION - SEPA OFFICIAL K.C. LAND & WATER RESOURCES ( ) FOSTER LIBRARY () K C PUBLIC LIBRARY ( ) HIGHLINE SCHOOL DISTRICT ( ) SEATTLE SCHOOL DISTRICT ( ) RENTON SCHOOL DISTRICT ( ) OLYMPIC PIPELINE ( ) VAL -VUE SEWER DISTRICT () WATER DISTRICT #20 ( ) WATER DISTRICT #125 () CITY OF RENTON PUBLIC WORKS () BRYN MAWR- LAKERIDGE SEWERMIATER DISTRICT ( ) RENTON PLANNING DEPT CITY OF SEA TAC ( )CITY OF BURIEN ( ) TUKWILA PLANNING COMMISSION MEMBERS ( ) TUKWILA CITY COUNCIL MEMBERS () CITY OF SEATTLE - SEPA INFO CENTER - DCLU () STRATEGIC PLANNING OFFICE' • NOTICE OF AU. SEATTLE RELATED PLNG PROJ. OTHER LOCAL AGENCIES DUWAMISH INDIAN TRIBE ( P.S. AIR POLLUTION CLEAN AGENCY ((�SOUND TRANSIT pUWAMISH RIVER CLEAN -UP COALITION •SENO NOTICE OF ALL APPLICATIONS ON DUWAMISH RIVER ( ) PUGET SOUND REGIONAL COUNCIL ( ) SW K C CHAMBER OF COMMERCE MUCKLESHOOT INDIAN TRIBE CULTURAL RESOURCES PROGRAM ( \FISHERIES PROGRAM WILDLIFE PROGRAM MEDIA ( ) SEATTLE TIMES ( ) SOUTH COUNTY JOURNAL P:\ADMTNISTRATIV E \FORMS \CHKLIST. DOC ( ) HIGHUNE TIMES ( ) CI.TUKWILA.WA.US.VWWV P*IC NOTICE MAILINGS FOR POMITS SEPA MAILINGS Mail to: (comment period starts on date of mailing) Dept. of Ecology Environmental Review Section *Applicant *Other agencies as necessary (checked off on attached list) Any parties of record * send only the staff report, site plan and the SEPA Determination KC Transit Division - SEPA Official would like to receive information about all projects that might affect transit demand Send These Documents to DOE: SEPA Determination (3 -part from Sierra) Findings (staff report, usu. with MDNS) SEPA Checklist (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) Affidavit of Distribution (notice was mailed or sent to newspaper) SHORELINE MAILINGS: Notice of Application for a Substantial Development Permit must be mailed to owners and to property owners within 500 feet of subject property, comments are due 30 days after the notice of application is mailed/posted. The notice of Application for Shoreline Substantial Development Permit must include a statement that any person desiring to submit written comments on the application or desiring to receive notification of the final decision on the application may do so within 30 days of the notice of application. If a hearing will be held on the application, the hearing notice must include the information that written comments may be submitted, or oral presentation made at the hearing. Shoreline Permit Notice of Decision: Mail to: (within 8 days of decision; 21 -day appeal period begins date received by DOE) Department of Ecology Shorelands Section State Attorney General *Applicant *Indian Tribes *Other agencies as necessary (checked off on attached list). *Any parties of record * send only the staff report, site plan and the SEPA Determination Send These Documents to DOE and Attorney General: Permit Data Sheet Shoreline Substantial Development Permit (3 -part from Sierra) Findings (staff report or memo) Shoreline Permit Application Form (filled out by applicant) Drawings/Plans of project (site plan, elevations, etc. from PMT's) - Site plan, with mean high water mark & improvements — Cross- sections of site with structures & shoreline - Grading Plan - Vicinity map SEPA determination (3 -part from Sierra) Findings (staff report or memo) SEPA Checklist (filled out by applicant) Any background studies related to impacts on shoreline Notice of Application Affidavit of Distribution (notice was mailed) P:M DMINISTRATIVEIFORMS\CHKLIST.DOC ■ Jam Free Printing Use Avery® TEMPLATE 5160® SALLE JOSEPH N 10225 56TH AVE S SEATTLE, WA 98178 ROSALES GRACIELA S 12843 35TH AVE S SEATTLE, WA 98168 SAMANEIGO FRANCES E & SALIDO 12937 TUKWILA INTERNATIONAL BLVD TUKWILA, WA 98168 j SOUVATDY KHAMPHY & SOUVATDY 13003 TUKWILA INTERNATIONAL BLVD TUKWILA, WA 98168. www.averycom 1- 800 -GO -AVERY SOUVATDY KHAMPHY & SOUVATDY SOULIPHONE 11206 SE 253RD PL KENT, WA 98030 BATUBARA CARTERIN 12844 35TH AVE S TUKWILA, WA 98168 SHOFAR BETH HA 13001 37TH AVE S TUKWILA, WA 98168 0 AVERY® 5160® TENANT . 12834 34TH AVE S TUKWILA, WA 98168 CARRENO EDUARDO 12855 35TH AVE S TUKWILA, WA 98168 ' TENANT 13004 33RD AVE S TUKWILA, WA 98168. TENANT 13003 37TH AVE S TUKWILA, WA 98168 LUDINGTON JANICE 13007 37TH AVE S TUKWILA, WA 98168 TENANT i LEHMBECK WILLIAM E & FLORENCE ' TENANT i 13007 37TH AVE S ; 13011 33RD AVE S 13013 37TH AVE S TUKWILA, WA 98168 TUKWILA, WA 98168 TUKWILA, WA 98168 DJUNED JUSUF M & NURBAITI 1 13015 33RD AVE S TUKWILA, WA 98168 MCLEOD THOMAS W & LISA 13017 37TH AVE S TUKWILA, WA 98168 PLANTE THOMAS & EDWARDS CONNI 13020 35TH AVE S SEATTLE, WA 98168 KRENKLIS GUNTIS CHRISTOPHER 13022 34TH AVE S. TUKWILA, WA 98168 WRAY JOYCE D 13025 38TH AVE S TUKWILA, WA 98168• eons ®A213AV STEWART KAREN J 13015 37TH AVE S TUKWILA, WA 98168 MUNTER RONALD B 13019 34TH AVE S TUKWILA, WA 98168 STILES GREGORY E & APRIL R 13021 33RD AVE S TUKWILA, WA 98168 ANSEL LLOYD DUANE 13024 34TH AVE S TUKWILA, WA 98168 ROSS HAROLD 13027 34TH AVE S TUKWILA, WA 98168 HUNTER BRIAN 13016 35TH AVE S ill TUKWILA, WA 98168. EGGEBRAATEN ROSEANNA 13020 34TH AVE S TUKWILA, WA 98168 MCLEOD C SAMUEL & LINDA K 13021 37TH AVE S TUKWILA, WA 98168 QUIGLEY RON K 13025 33RD AVE S TUKWILA, WA 98168. PHILLIPS MICKEAL 13027 37TH AVE S TUKWILA, WA 98168 AII3AV-O9-008-1. . ®09LS 31V10N31®MeAV eSti WOYMeAe•nmANIn 6unupd aai j wer Jam Free Printing Use Avery® TEMPLATE 5160® www.averycom 1- 800-GO -AVERY • .I TENANT ' I LE QUOC T & TAM L NGUYEN 13628 33RD AVE S H ; _13029 33RD AVE S • TUKWILA, WA 98168 ' i" TUKWILA, WA 98168 1 1 DIETZ WILLIAM T 13030 35TH AVE S SEATTLE, WA 98168 BYRUM JOSH S 13032 33RD AVE S TUKWILA, WA 98168 ' BOUN PHANNY 13042 TUKWILA INTERNATIONAL BLVD TUKWILA, WA 98168 BROWN DOUGLAS G & CARMELA S . . 13031 33RD AVE S TUKWILA, WA 98168 HUMBLE PAMELA.A 13041 38TH AVE S TUKWILA, WA 98168 WESLEY LORI M 13044 34TH AVE S TUKWILA, WA 98168 GRAVES DAMON SHIRACK ROBERT P 1 13048 34TH AVE S 13050 33RD AVE S TUKWILA, WA 98168 ' TUKWILA, WA 98168 WADE JOSEPH B & ANITA J 13200 37TH AVE S TUKWILA, WA 98168 METTLER NATHANIEL M 13209 37TH AVE S TUKWILA, WA 98168 MITCHELL CHRISTA LYNN 13217 38TH AVE S TUKWILA, WA 98168 MULLET DAVID 13205 34TH AVE S TUKWILA, WA 98168 MCCUISTION ROBIN E 13210 37TH AVE S TUKWILA, WA 98168 MULLET DAVID P 13221 34TH AVE S TUKWILA, WA 98168 C\ AVERY® 5160® LE HIEN VAN & HUONG THU TRAN 13029 37TH AVE S TUKWILA, WA 98168 EDWARDS JOYCE M 13031 37TH AVE S TUKWILA, WA 98168 TENANT 13042 33RD AVE S TUKWILA, WA 98168 TENANT 13047 34TH AVE S TUKWILA, WA 98168 CHITTENDEN NORMAN T 13057 34TH AVE S TUKWILA, WA 98168 WILDER ROY M 13206 34TH AVE S. TUKWILA, WA 98168 DONALDSON MR & MRS 13216 34TH AVE S TUKWILA, WA 98168 NIEHOFF GERALD 13222 37TH AVE S TUKWILA, WA 98168 TENANT TENANT BOTROS TALAT 13224 35TH AVE S 13228 37TH AVE S 13232 S 37TH AVE . SEATTLE, WA 98168 TUKWILA, WA 98168 . SEATTLE, WA 98169 WITTMAN KENNETH C & SUSAN A 13301 34TH AVE S TUKWILA, WA 98168 e09LS ®AU3Ad Q WILLIAMS THELMA 13305 35TH AVE S TUKWILA, WA 98168 I DREAM CATCHER HOMES LLC 13619 MUKILTEO SPEEDWAY D5 LYNNWOOD, WA 98087 AU3AV-O9-008-I, ®091S 31V1dV131®Aany asf Workanewtmm 6uRu!d aaJJ weI Jam Free Printing Use Avery® TEMPLATE 5160® LOPEZ NAOMI P 17223 SYLVESTER RD SW NORMANDY PARK, WA 98166 BERHANU YOHANES 3226 S 130TH ST TUKWILA, WA .98168 BROOME PADDY M 3320 S 132ND ST TUKWILA, WA 98168 www.avery.com 1-800-GO-AVERY • YOSHIKAWA TERRANCE 2416 32ND AVE W SEATTLE, WA 98199 JOHNSON RICHARD L . . 3306 S 132ND ST TUKWILA, WA 98168 RIESS CINDY D & CHARLES A 3403.5 133RD ST TUKWILA, WA 98168 TENANT , • NESS EDDIE J ; I BLANKMEYER JAMES V C & CLEOPA 3412 S 132ND ST . . ' 34807 176TH AVE SE I ' 3501 S 130TH ST TUKWILA, WA 98168 . AUBURN, WA 98092 II TUKWILA, WA 98168 CI. AVERY® 5160® YOSHIKAWA TERRANCE 2416 32ND AVE W SEATTLE, WA 98199 MULLET ELIZABETH T 3309 S 132ND ST TUKWILA, WA 98168 LEWIS CRAIG A 3404 S 132ND ST • TUKWILA, WA 98168 TENANT 3502 S 130TH ST TUKWILA, WA 98168 SIBRIAN AGNES K 3510 S 132ND ST TUKWILA, WA 98168 1! 'II (. I HUYNH HUNG V & PHUONG T 1iNGUYE. I ; j 3507 S 130TH ST 11 TUKWILA, WA 98168 i . GARDINER STEPHEN C ,•3511S130THST TUKWILA, WA 98168. WATTERS HEIDI •i3510S130THST • TUKWILA, WA 98168 MCFARLANE K EUGENE 3516 S 130TH ST i TUKWILA, WA 98168 ' KOLLASCH JAMES M TENANT ' MCLEOD SAMUEL M & SUSAN E 3517 S 130TH ST 3521 S 130TH ST . . 3522 S 130TH ST 1 TUKWILA, WA 98168 :: TUKWILA, WA 98168 TUKWILA, WA 98168 TENANT TENANT LOBO EDWIN .& JANET 3528 S 130TH ST 3705 S 130TH ST 3801 S 132ND PL TUKWILA, WA 98168 TUKWILA, WA 98168 TUKWILA, WA 98168 CASTRO PETE & SOCORRO 429 SW 335TH ST FEDERAL WAY, WA 98023 SALLE FAMILY L L C 5611 S RYAN ST SEATTLE, WA 98178 • HARLAN TIMOTHY & REBECCA 600 UNIVERSITY ST 2701 SEATTLE, WA 98101 CONNELL RAYMOND A & ANITA J 633 S SEWARD PARK AV SEATTLE, WA 98118 ®09%S ®A213AV LOISELLE LEROY C •1! PO BOX • 412 I 1 FALLS CITY, OR 97344 AH3AV-09-008 -1. wo) Jane•nMnnn MACKLAND LIVING TRUST THE PO BOX 48118 SEATTLE, WA 98148 ®09LS 31V1dIW31®IlJany as8 6uRuld eaad wer Jam Free Printing Use Avery® TEMPLATE 5160® SMITH PHILIP R & ELEANOR J PO.BOX 68233 1 SEATTLE, WA 98168 www.avery.com 1- 800-GO -AVERY • Q aA 0 ® 09S ®A213AV woatiJeAe annnn j CAAVERY® 5160® 00965 31MdW3J. ®IGaAV esn 6uFuud 913J1 wer • City of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director NOTICE OF COMPLETE APPLICATION July 13, 2006 Mr. George K. Hirai 15615 NE 62nd CT. Redmond, WA 98052 Re: Notice of complete application; L06 -013 Dear Mr. Hirai: The Department of Community Development received your short plat and SEPA application on July 3, 2006. A letter from the Department on July 7, 2006, noted that the application was incomplete and requested additional information. On July 11, 2006 the additional information was submitted to the City. Based on a review of your application for submittal requirements for SEPA review, your application is deemed complete as of July 13, 2006. A notice of land use application will be distributed within 14 days of this date. The next step is for you to install the notice board on the site within 14 days of the date of this letter. You received information on how to install the sign with your application packet. If you need another set of those instructions, you may obtain them at the Department of Community Development (DCD). Also, you must obtain a laminated copy of the Notice of Application to post on the board. This notice is also available at DCD. After installing the sign with the laminated notice, you need to return the signed Affidavit of Posting to our office. The application and associated materials have been routed to other City departments for review. Staff will be in contact with you soon to discuss the project. This determination of complete application does not preclude the ability of the City to require that you submit additional plans or information, if such information is necessary to ensure the project meets the substantive requirements of the City or to complete the review process. If you have any questions, you can contact me at (206) 431 -3684 or by email at bmiles@ci.tukwila.wa.us. Sinr.,erel rafidon J. Miles Assistant Planner cc. File (E06 -013) 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 TO: City of Tukwila Department of Community Development File Number L°6 -013 LAND USE PERMIT ROUTING FORM 1 Building LI Planning 1 I [Public Works II Fire Dept. -!l Police Dept. 0 Parks /Rec Project: VI \ ((Ai' g tbrIL QC VtIT nod-- Update date: Address: Cc tMe m 0 prepared by: Date 2 transmitted: 111 l�Jk Response requested by: 1511 �p` Staff �q coordinator: J \ler Date response received: REVIEWERS: Please specify how the attached plans conflict with your ADOPTED development regulations, including citations. Be specific in describing the types of changes you want made to the plans. When referencing codes, please identify the actual requirement and plan change needed. The Planning Division review does not supplant each department's ability to administer its own regulations and permits. However, project consistency at the Planning review stage is important to minimize significant later design changes. More than minimal design changes require further Planning Commission review, even if alteration is required to satisfy a City requirement. This further review is typically a minimum 60 -day process. Requirements based on SEPA (e.g., not required by an adopted development regulation) MUST identify the impact being mitigated, the policy basis for requiring mitigation, and the method used to calculate the mitigation required. Calculations of project impacts and the mitigation required (e.g., water capacity, road level of service analyses, or turning analyses) may be required of the applicant. COMMENTS (Attach additional comment sheets and/or support materials as needed.) Plan check date: Comments Update date: prepared by: TO: • City of Tukwila Department of Community Development File Number Lo&— 013 LAND USE PERMIT ROUTING FORM Planning i ,l Public Works ! F! Fire Dept. l ] Police Dept. Imo!! Parks /Rec Project: kl '4 4 N avclprite 1--- Address: Date transmitted: 11 '513(s Response requested by: 211 lf, Staff coordinator: M +) �� 1 p ate response received: REVIEWERS: Please specify how the attached plans conflict with your ADOPTED development regulations, including citations. Be specific in describing the types of changes you want made to the plans. When referencing codes, please identify the actual requirement and plan change needed. The Planning Division review does not supplant each department's ability to administer its own regulations and permits. However, project consistency at the Planning review stage is important to minimize significant later design changes. More than minimal design changes require further Planning Commission review, even if alteration is required to satisfy a City requirement. This further review is typically a minimum 60 -day process. Requirements based on SEPA (e.g., not required by an adopted development regulation) MUST identify the impact being mitigated, the policy basis for requiring mitigation, and the method used to calculate the mitigation required. Calculations of project impacts and the mitigation required (e.g., water capacity, road level of service analyses, or turning analyses) may be required of the applicant. COMMENTS (Attach additional comment sheets and/or support materials as needed.) 9 Plan check date:�� 'A'PP Comments prepared by: Update date: • City of Tukwila Department of Community Development LAND USE PERMIT TO: ILt Planning hPubIIc Works t. File Number Lob- 013 ING FORM 0 Police Dept. ra Parks /Rec Project: Address: transmitted: 111 Date 51JC Response requested by: 2111q,, Staff Al � (3. coordinator: A I Date response received: REVIEWERS: Please specify how the attached plans conflict with your ADOPTED development regulations, including citations. Be specific in describing the types of changes you want made to the plans. When referencing codes, please identify the actual requirement and plan change needed. The Planning Division review does not supplant each department's ability to administer its own regulations and permits. However, project consistency at the Planning review stage is important to minimize significant later design changes. More than minimal design changes require further Planning Commission review, even if alteration is required to satisfy a City requirement. This further review is typically a minimum 60 -day process. Requirements based on SEPA (e.g., not required by an adopted development regulation) MUST identify the impact being mitigated, the policy basis for requiring mitigation, and the method used to calculate the mitigation required. Calculations of project impacts and the mitigation required (e.g., water capacity, road level of service analyses, or turning analyses) may be required of the applicant. • COMMENTS (Attach additional comment sheets and/or support materials as needed.) atis Cowca_A,wo, Plan check date: 1 [tr"q61.0 Comments prepared by: Update date: • rCoin4 CONSULTING ENG INEERS, INC. Civil Engineering Surveying • Land Use Consulting . Drainage . CAD' P. 0. Box 50524. Bellevue. WA 98015. T 425.641.4535. F 425.641.4548 Hirai Development (Owners) Mr. George Hirai George Hirai Inc., LLC 1561.5 NE 62 "d Court Redmond`, WA 98052 P 206.786.2981 • City of Tukwila'Project.No. PRE - 04 — 02 Prepared By: Mazen Haidar, P.E. MEED;na Consulting Engineers, Inc. P. O. Box 50524 Bellevue, WA 980.15 • • Date Prepared: ��Dp� May 25th, 2006 CITYO TIUKWILA JUN • 12 2006 PERMIT CENTER EXPIRES 5/27/08. STAMP IS NOT VALID UNLESS SIGNED'AND DATED Disclaimer: This report was prepared at the request of our Client Mr. George Hirai, for the properties located at intersection of S 132nd Street and Pacific HWY, Tukwila, Washington 98168, parcel numbers 7359600670, 735960069, 7359600655, 7359600654, and 7359600653 Tukwila Washington. r1EDind Consulting Engineers, Inc., (MCE), prepared this report for the exclusive use of its staff, and its authorized agent(s), and for this specific project development as described herein. Any use of, or reliance on this report, or any of its contents for any revisions to any of this project's information, design plans, documentation, and / or the herein described development's improvements without the written approval from r1ED;na Consulting Engineers, Inc., (MCE). is hereby forbidden. Similarly, any use of, or reliance on this report, or any of its contents for the preparation of any other project reports, plans and technical documentation by others, without . written approval from r1EDina Consulting Engineers, Inc., (MCE), is hereby forbidden. o0o Technical Information Report (TIR) 05-251 -2006 nEDind Consulting Engineers. Inc. IMEDINA ProjectsIHirai SPIEngineering TABLE OF CONTENTS Section 1, Project Overview • Vicinity Map • Existing Site Conditions Plan Section 2, Conditions & Requirements • Core Requirements Summary Section 3, Off -Site Analyses • Up- stream Drainage • On -site Drainage • Downstream Drainage Section 4, Flow Control & Water Quality Analyses and Designs • Flow Control Design Calculations • Water Quality Design Calculations Section 5, Conveyance System Analyses • On -Site Conveyance Capacity Calculations Section 6, Special Reports and Studies • Geotechnical Report Date March 30, 2006 by Nelson Geotechnical. Section 7, Other Permits • City Of Tukwila Right -Of -Way Use Permit Technical Information Report (TIR) 05-251 -2006 IMEDINA ProjectsWirai SPIEngineenng :7eD:12d Consulting Engineers. Inc. Section 8, Temporary Erosion and Sedimentation Control (TESC) Analyses • Standard Silt Fabric Fence • Standard Construction Entrance • Catch Basin Protection Inserts Section 9, Bond Quantities Calculations • Will be included in the next plans submittal Section 10, Operation and Maintenance Manual • Operation and Maintenance Manual Operation and Maintenance procedures are per the 1998 King County Surface Water Design Manual (KCSWDM) Guidelines. 000 Technical Information Report (TIR) 05- 251 -2006 1772DIIZd Consulting Engineers, Inc. IMEDINA ProjectslHirai SPIEngineering Section 1 PROJECT OVERVIEW Technical Information Report (TIR) 05-251 -2006 MEDiild Consulting Engineers. Inc. \MEDINA ProjectsIHirai SPIEngineering 3tI .S7.-1261T=St 2 S i5 t5; t fS-126th St 4 fS= 128th =St �S ty • NN fi , --1----____-1 r .-12Bti t�`S- /ZySt�� `�N i' --. cn 5 130th1 `` t. li ____q.. .,,.,,\, g //A 2 1.FL l 1(J �` �r �� 0- _J �,_ •� \ P i' a =S= 136th =St.` R— _s_137th_St T Rivertone_ -i'� I1 vj Southgdil# A t ''*s-..1 n =st ./l ) Tukwil� ;jm'1 V.r'J rte` d`� S -1- 37th -St" I N\ \\ F,. ; \-. -:: 5= 139th -St S_139th =St� to (S= 139th=St) 4 $ =140th St "?� 5.14'..st -St 1 to �m��i, i r _1dst,St t, i~ 11 \\ w m � \w I I W N Vicinity Map o0o Project Overview: The project site is located in the Northwest '/4 of the Northwest 1/4 of Section 15, Township 23 North, Range 4 E, W.M. in the City of Tukwila, State of Washington. The site is also located at northwest corner of S. 132nd Street and Pacific. Highway (99) intersection, Tukwila, Washington. The subject site comprises of 5 existing separate legal vacant parcels totaling approximately 0.59 acre of vacant land. The site is bordered across its westerly boundary line by an existing 16 -feet wide Alley, and fully developed properties immediately to the west and north, by Pacific Highway (99) to east, and by South 132nd Street to the south.. See enclosed vicinity map. The site is vacant with natural ground cover that consists of pasture, shrubs, black barriers and few trees. The natural site topography is oriented from south and southwest to the north and northeast with an overall slopes ranging from 5% to 20% in the easterly portion of the site. Please refer to the enclosed soils report prepared by Nelson Geotechnical for Associates, Inc. for information related to the site existing surface and subsurface soils. Four to five feet high of rockery wall do exist across the easterly property line separating the site natural grade from Pacific Highway (99). See attached existing conditions exhibit. The development proposal is to 5 build single - family residences on the already exist 5 Tots. A 16 -feet wide paved roadway and 4 -foot wide paved walkway will be installed in the adjacent Alley to the west. A 4.5' access and utility easement will be granted across the westerly property line to accommodate required walkway improvements. Additionally, an underground Combined Wet -R /D concrete vault will be installed at the north terminus of the proposed 16 -feet paved access for storm water quantity and quality control pursuant to the 1998 King County Surface Water Design Manual guidelines. Also, a 6 -in private sewer line will be installed along the easterly property line inside a proposed 10 -feet sewer easement pursuant to Valvue Sewer District guidelines. Private water lines and meters will also be installed in accordance with the King County Water District No. 125 Standards to serve the proposed 5 single - family residences. See Attached developed conditions exhibit oOo Technical Information Report (TIR) 05-251-2006 IMEDINA ProjectslHirai SPIEngineering M Dind Consulting Engineers, Inc. • • NW 1 /4, NW 1 /4, SEC. 15, T. 23 N., R. 4 E., W.M. • 21 \ \ _e.L.OGK- \ \ 20 \ \\ \ <t '\ \ \ \ \ \ �\ \ \_ \\ \ \.` -\ \.((( \ / ` \ \ \\ 5 \ I. / 18 17 \ a� \/ \ I cNt \ • • :iWAl -.7,1% c; \ Y� GRAPHIC SCALE UIMIES CONFLICT NOTE THE CONTRACTOR SMALL BE COMPLETELY RESP016HE FOR VERIFYING HORIZONTAL AND VERTICAL LOCATIONS. DIMENSIONS. AND DEPTHS OF ALL EXISTING UNDERGROUND AND ABOVE GROUND UTILITIES. WHETHER SHOWN ON THESE PLANS OR NOT. THIS SHALL INCLLDE CALLING UTILITY LOCATE AT (800) 425.5155 PRIOR TO CONSTRUCTICN ACTIVITIES STMT. AND THEN POTHOLING ALL EXISTING UTIRES AT LOCATION OF NEW UTILITY CROSSINGS TO PNYS/CN1Y VERIFY WHETHER OR NOT CONFLICTS EXIST. LOCATIONS OF SAID UTILITIES AS SHOWN ON 1HE5E PLANS ARE NOT GUARMTEED AND ARE MUST BE VERIFIED BY THE CONTRACTOR. IF CONFLICTS SHOULD OCCUR. THE CONTRACTOR SHALL IMMEDIATELY NOTIFY THE CITY INSPECTOR AND OoY E CONSULTING ENGNEERL INC. AN0IDR THE ENDORSING ENGINEER TO RESOLVE CONFLICT ISSUES PRIOR TO PROCEEDING WITH CONSTRUCTION ACTNIIE5. • • P as \• \ \ \\ \ 1\ \ • \ \ N /•Y� \ \ \ \� \X \ �S \ — — — \ \ \ \ \ \ 8 \ \ \ \\ ` \\ \ 11 \ '' \ \ \ \ \ 1 \ A/' \ \ \ \ \ 1 1 14 \ \ \ \ ` -. N, o 1/ re \ \ \ \ 11 "\ I \ \ , KI��\ stcosco.X. no co d� \/ \\ . OKSE05:14 ,.cawlnA ,.,„ THE TOPOGRAPHIC SURVEY INFORMATION SHOWN ON INS PLAN WAS PROVIOE0 BY NEAP GILMA N S. ASSOCIATES. INC. PRl0ES51ONAL LAND SURVEYORS. 425) NM, 212. P.O. BOX 205. WGGGPBRLLE. WA 50012. SNOWY CONS(. TING ENGINEERS. INC. 200205100 ENDORSING ENGINEER ARE NOT RESPONSIBLE FOR LIE COORECITE55 ND 11E ACCURACY O TOPO SURVEY INFORMATION S.M.. ON THIS PLAN AND ARE NOT RESPONSIBLE FOR ANY ERRORS OR OMISSIONS OF TOPO SURE LEY IKORNATO! NOT SHOWN ON THIS PLAN. NSRIDIAN' ALA 0.100. EQ*IP25NI b PRO'EDURE'; RFNCH■ARHS *L"'""" .w. GC NSRi Nrcrt •r CONDOION Lvt.¢.tw.ri[ wri L'ipMUp 50 P[�Re.tMA��� rtrna(..fa t• LO1 12 1.000 So tot �) I.rn So rt- REFERFNEES' LEGEND OP 4S 000. •OST SYMBOLS I MAP. , w. 0 otwl En ..rA ...,u' `rt. SM T 0 ■ •T••■t ,.ta COK121‘ N•10. (-HEW TAN F. MIS 00 ..IXmuO15 ( .0401 04.40 110.0 vot 0•00040. 00/0 STORI• 0004 04 I FCAL DESCRIP BON 16 0 aS. • aS(,m aa. a.A scrow` - •�°°qa..v b..., CALL 451 OURS BEFORE YOU DOG MOO) 424-5555 PR LLONOO�1Z Y NOT FOR OOMST ©TOGO M Existing Conditions 1 a 1 E a Raw Ns C2 C6 DE TOPOGRAPHIC SURVEY INFOERIATON SHCAVT/ ON 045 PLAN WAS PROVIDE-0 BY READ GIL/AAN ASSOOATES. INC_ PROFESSOR& WO SURVEYOR!, (439) 456-1251. P. 0. 608 289.1NO045WtLE WA 98072. CONSUL TING ENGIYEERS. PC AND / CR THE DOORSI. DOWER ARE NOT RESPONSIBLE FOR THE COGRECIWESS ATO PIE ACCURACY CF TORO SURVEY IAPORAIATION SHOWN ON THIS PLAN. ANO ARE NOT RESPONSIBLE FOR ANY 0.0173 OR 0045.110AS OL TOPO SUREVEY INFORMATION MOT SIFYIPI RCS WAX .\\ r N l\.\' \ \ s NW 1/4, NW 1/4, SEC. 15, T. 23 N., R. 4 E., W.M. • 421, oh.. c-r4i GRAPHIC SCALE . • 111•11• AO 2/0 700 • 2.1•40 479.07 IIIIII 1111111MIL 111111111 III Ell 11111 lw■-■11-19111E1111111 0220. 20 111 'III Milli' 40. 200 Az. . . .... . ..... 110 11 . i."611.111! 1+00 1+50 2+00 2+50 3+00 3+50 4,00 414 trC0•41.07• .70 n 2. PP. 0•01.4•371 00194 C191•49[17 510094. 700 00095t 0••■•417. C•99.00 504,4.04 00.50 404457 .021002.2 T0E.PPEPt PET et 4C030120 0[40•CmG S09. 094071.9 16-Feet Access Driveway / 4 1 77 ---5132018 C0431701. 94301.0 Sric 10 • 11740 IX 0.7•140 • sp•,ar 1010714,.171f. Is. 03 t .P170 .0.40.410• • 111.. 01.040000 01. 00 SCALE ............. 11:1".=.20' ...... . . 107264000 • 90 SS ' 11400•4•SENI• 1a, •S 4400 04 • .00 •14. 7904 49.0 0. ;.•r .51•• SP14P. 41I 314,2 c. yrls yd Cu. ytlf 0•T 10, tI,20 rio E X 1ST prop 51 39 0" Conoevt• CALL 48 HOURS BEFORE YOU DIG (800) 424-5555 PRELORMARY NOT FOR CONSTRUCTOON Developed Conditions 1 1 a 2 CO 0- CL) E 0 -0 c a) - 0 c (T3 (0 0 -(75 (0 .100 mr..E • 022■00 • PT 00/ 25I2COS C4 C6 Section 2 CONDITIONS AND REQUIREMENTS Technical Information Report (TIR) 05-251-2006 M Dilfd Consulting Engineers. Inc. IMEDINA ProjectslHirai SPIEngineering Core Requirements Summary: Core Requirement # 1, Discharge at the Natural Location, The site existing conditions indicate the site surface flows are directed to the north and northeast of the site, under the developed conditions surface flows will discharge at the northeast corner of the site downstream of the proposed retention /detention R/D facilities. Core Requirement # 2, Off-site Analysis, The downstream drainage course is discussed in Section 3 in this report based on information provided to us the City of Tukwila staff. Core Requirement # 3, Flow Control, The proposed development will provide on -site 12 -in conveyance system and on- site Combined Wet -R /D underground concrete vault for Level - I peak flow control under the developed conditions. Core Requirement # 4, Conveyance System, 12 -in CPEP on -site conveyance system will be provided for the developed conditions and will be routed to the proposed R/D facilities. Core Requirement # 5, Erosion and Control Sedimentation, During construction, TESC measures will be provided such as Fabric Silt Fence, Straw Bales, Construction Entrance, and Catch Basins Inserts. Core Requirement # 6, Maintenance and Operation, The maintenance and operation of the proposed R/D facilities will be the responsibility of the project developers / Owners. Maintenance and Operation Manual consistent with the 1998 King County Surface Water Design Manual (KCSWDM) guidelines is included in this report Core Requirement # 7, Financial Guarantees and Liability, The financial guarantees and liability will be posted by the project owners as required by the City of Burien. Core Requirement # 8, Water Quality, The proposed development will provide an underground concrete Combined Wet -R /D facility consistent with 1998 KCSWDM guidelines. Technical Information Report (TIR) 05-251 -2006 %MEDINA ProjecfsIHirai SPIEngineering 17E0774 Consulting Engineers. Inc. Special Requirement # 1, Other Adopted Area - Specific Requirements, The subject development is not subject to this requirement and there are no known Area - Specific requirements that apply. Special Requirement # 2, Floodplain / Floodway Delineation, The subject development does not contain and is not adjacent to any known wetlands, stream, depressions, or lakes; therefore this requirement does not apply. Special Requirement # 3, Flood Protection Facilities, The subject development does not contain and is not adjacent to any known wetlands, stream, depressions, or lakes; therefore this requirement does not apply. Special Requirement # 4, Source Control, The proposed development is not a commercial or industrial development; therefore this requirement does not apply. Special Requirement # 5, Oil Control, The subject development is not defined as a High -Use Site by the 1998 KCSWDM, and therefore, this requirement does not apply. o0o Technical Information Report (TIR) 05-251-2006 iZEDi/fd Consulting Engineers. Inc. IMEDINA ProjectsVlirai SPIEngineenng Section 3 OFF -SITE ANALYSES Technical Information Report (TIR) 05-251 -2006 l7EDDId Consulting Engineers. Inc. IMEDINA ProjectslHirai SPIEngineering Off — Site Analyses, Up- Stream Drainage Analysis: Based on the site topographic survey map and based our site evaluation and drainage investigation, it appears that there are insignificant amount of up stream surface runoff that sheet flow onto the site from very small areas adjacent to the site immediately to south and southwest which of consist of back yard areas of adjacent homes. On -Site Drainage Analysis: The existing site topography directs surface runoffs in sheet flow format toward the northeast corner of the site which is the site natural discharge location. During our site evaluation and drainage investigation we did not observe any existing drainage system on site and we did not notice any signs of erosion, flooding or other drainage problems. Downstream Drainage Analysis: Surface runoffs leave the site in sheet flow format discharging directly to an existing conveyance system located on the west side. of Pacific Highway. Surface flows are then conveyed via existing 12" concrete pipe for approximately 200 -feet in the northerly direction before discharging into an existing catch basin where it enter an existing 24" concrete pipe that conveys surface flows under Pacific Highway to an existing drainage course through private properties. Based on information provided to us by City of Tukwila staff it appears that surface flows continue for several hundred feet in the north and northeasterly direction before joining other flows in Riverton Creek. Surface flows continue in Riverton Creek for additional several hundred feet before discharging into the Duwamish River beyond the downstream '/4 mile location. o0o Technical Information Report (TIR) 05-251 -2006 IMEDINA ProjectsVlirai SPIEngineering M D171d Consulting Engineers. Inc. Section 4 FLOW CONTROL & WATER QUALITY ANALYSES AND DESIGNS Technical Information Report (TIR) 05-251-2006 MED1/74 Consulting Engineers. Inc. IMEDINA ProjectsWirai SPIEngineering Flow Control & Water Quality Analyses and Designs Based on information contained in the enclosed Geotechnical Report prepared by Nelson Geotechnical dated March 30, 2006, the use of infiltration and / or dispersal trenches do not appear feasible for the site developed conditions. Since the proposed development is subject full compliance with the 1998 King County Surface Water Design Manual (KCSWDM), the development will provide Combined Wet -R /D facilities subject to full compliance with Level — I runoff release (Conveyance Protection Standards). Individual roof tops, driveways, yards, in addition to the proposed on -site paved access and paved walkway will all be connected to this proposed Combined Wet - R/D facilities. Please refer to design calculations shown below: Area Calculations: Pre - Developed Conditions, Total Site + Alley Area = 29,932 s.f. = 0.687 ac. • Impervious areas: Existing Gravel Driveway (to be removed) = 1,705.0 s.f. Total = 1,705.0 s.f. apply 50% for Effective Impervious Surface b Total Impervious Surface = 1,705.0 X 0.5 = 852.0 s.f. = 0.02 ac. • Pervious areas: Pasture = 0.687 — 0.02 = 0.667 ac For KCRTS Analysis Use: Total Project Area = 0.687 ac. Till impervious = 0.02 ac Till Pasture = 0.667 ac ouo Technical Information Report (TIR) 05-251 -2006 ncDina Consulting Engineers. Inc. IMEDINA Projects%Hirai SPIEngineenng KCRTS Command INFORMATION about this program KCRTS Command CREATE a new Time Series Production of Runoff Time Series Project Location: Sea -Tac Computing Series: Predev.tsf Regional Scale Factor: 1.00 Data Type: Reduced Creating Hourly Time Series File Loading Time Series File :C: \KC_SWDM \KC_DATA \STTP6OR.rnf : Till Pasture 0.67 acres Loading Time Series File :C: \KC_SWDM \KCDATA \STEI60R.rnf : Impervious 0.02 acres Total Area: 0.69 acres Flow Frequency Analysis Time Series File: Predev.tsf Project Location: Sea -Tac - -- Annual Peak Flow Rates-- - Flow Rate Rank Time of Peak (CFS) Flow Frequency Analysis - - Peaks - - Rank Return Prob. (CFS) Period 0.050 0.022 0.048 0.008 0.027 0.045 0.044 0.090 Computed 2 7 3 8 6 4 5 1 Peaks 2/09/01 1/05/02 2/28/03 8/26/04 1/05/05 1/18/06 11/24/06 1/09/08 15:00 16:00 3:00 2:00 8:00 16:00 4:00 6:00 0.090 0.050 0.048 0.045 0.044 0.027 0.022 0.008 0.077 In summary, for the pre - developed site conditions we have: Q2 = 0.027 cfs Qio = 0.048cfs o0o 1 100.00 2 25.00 3 10.00 4 5.00 5 3.00 6 2.00 7 1.30 8 1.10 50.00 0.990 0.960 0.900 0.800 0.667 0.500 0.231 0.091 0.980 Technical Information Report (TIR) 05-251 -2006 1750k74 Consulting Engineers, Inc. IMEDINA Projectslhlirai SPIEngineering Developed Conditions: Total area = 29,932.0 s.f. = 0.687 ac. Total Impervious Areas: Lot # 9, House (800 s.f.) + DWY (400 s.f.) Lot # 10, House (1,700 s.f.) + DWY (400 s.f.) Lot # 11, House (1,700 s.f.) + DWY (560 s.f.) Lot # 12, House (1,700 s.f.) + DWY (900 s.f.) Lot # 13, House (1,700 s.f.) + DWY (880 s.f.) Paved 16 -feet Road + 4 -foot Paved Walkway (4,900 s.f.) Total = 15,640 s.f. = 0.36 ac (Till Impervious) Total Pervious Areas: 0.687 — 0.36 = 0.327 ac (Till Grass) b For KCRTS Analysis Use: Total area = 29,932 s.f. = 0.687 ac. Till impervious = 0.36 ac Till Grass = 0.327 ac o0o Technical Information Report (TIR) 05-251 -2006 /7 DAld Consulting Engineers, Inc. IMEDINA Projects%Hirai SPIEngineering KCRTS Command CREATE a new Time Series Production of Runoff Time Series Project Location: Sea -Tac Computing Series: dev.tsf Regional Scale Factor: 1.00 Data Type: Reduced Creating Hourly Time Series File Loading Time Series File :C: \KC_SWDM \KC_DATA \STTG6OR.rnf : Till Grass 0.33 acres Loading Time Series File :C: \KC_SWDM \KC_DATA \STEI60R.rnf : Impervious 0.36 acres Total Area: .0.69 acres Flow Frequency Analysis Time Series File: dev.tsf Project Location: Sea -Tac - -- Annual Peak Flow Rates-- - Flow Rate Rank Time of Peak (CFS) Flow Frequency Analysis - - Peaks - - Rank Return Prob (CFS) Period 0.116 0.092 0.140 0.096 0.116 0.124 0.139 0.239 Computed 5 8 2 7 6 4 3 1 Peaks 2/09/01 1/05/02 2/27/03 8/26/04 10/28/04 1/18/06 10/26/06 1/09/08 2:00 16:00 7:00 2:00 16:00 16:00 0:00 6:00 0.239 0.140 0.139 0.124 0.116 0.116 0.096 0.092 0.206 In summary, for the pre - developed site conditions we have: Q2 = 0.116 cfs Qio = 0.139 cfs o0o 1 100.00 2 25.00 3 10.00 4 5.00 5 3.00 6 2.00 7 1.30 8 1.10 50.00 0.990 0.960 0.900 0.800 0.667 0.500 0.231 0.091 0.980 Technical Information Report (TIR) 05-251 -2006 17FD1114 Consulting Engineers. Inc. IMEDINA ProjectsW,rar SPIEngtneenng • Performance Standards: The R/D performance standards are: Category Flow Control Water Quality Performance Standards Level — I Control Conveyance Protection Standards. Combined Wet -R /D Vault Source 1998 KCSWDM, KCRTS 1998 KCSWDM, and Stormwater • Flow Control Design Calculations: Retention /Detention Facility Type of Facility: Detention Vault Facility Length: Facility Width: Facility Area: Effective Storage Depth: Stage 0 Elevation: Storage Volume: Riser Head: Riser Diameter: Number of orifices: Orifice # 52.00 ft 17.25 ft 897.0 sq. ft 4.00 ft 191.00 ft 3588.0 cu. ft 4.00 ft 12.00 inches 2 Full Head Pipe Height Diameter Discharge Diameter (ft) (in) (CFS) (in) 1 2 0.00 0.80 0.035 2.80 0.69 0.014 4.0 Top Notch Weir: None Outflow Rating Curve: None Technical Information Report (TIR) 05-251 -2006 1712D1174 Consulting Engineers. Inc. IMEDINA ProjectsHirai SPIEngineering Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac -ft) (cfs) (cfs) 0.00 191.00 0. 0.000 0.000 0.00 0.01 191.01 9. 0.000 0.002 . 0.00 0.02 191.02 18. 0.000 0.002 0.00 0.03 191.03 27. 0.001 0.003 0.00 0.04 191.04 36. 0.001 0.004 0.00 0.05 191.05 45. 0.001 0.004 0.00 0.06 191.06 54. 0.001 0.004 0.00 0.07 191.07 63. 0.001 0.004 0.00 0.17 191.17 153. 0.004 0.007 0.00 0.27 191.27 242. 0.006 0.009 0.00. 0.37 191.37 332. 0.008 0.011 0.00 0.47 191.47 422. 0.010 0.012 0.00 0.57 191.57 511. 0.012 0.013 0.00 0.67 191.67 601. 0.014 0.014 0.00 0.77 191.77 691. 0.016 0.015 0.00 0.87 191.87 780. 0.018 0.016 0.00 0.97 191.97 870. 0.020 0.017 0.00 1.07 192.07 960. 0.022 0.018 0.00 1.17 192.17 1050. 0.024 0.019 0.00 1.27 192.27 1139. 0.026 0.020 0.00 1.37 192.37 1229. 0.028 0.020 0.00 1.47 192.47 1319. 0.030 0.021 0.00 1.57 192.57 1408. 0.032 0.022 0.00 1.67 192.67 1498. 0.034 0.022 0.00 1.77 192.77 1588. 0.036 0.023 0.00 1.87 192.87 1677. 0.039 0.024 0.00 1.97 192.97 1767. 0.041 0.024 0.00 2.07 193.07 1857. 0.043 0.025 0.00 2.17 193.17 1947. 0.045 0.026 0.00 2.27 193.27 2036. 0.047 0.026 0.00 2.37 193.37 2126. 0.049 0.027 0.00 2.47 193.47 2216. 0.051 0.027 0.00 2.57 193.57 2305. 0.053 0.028 0.00 2.67 193.67 2395. 0.055 0.028 0.00 2.77 193.77 2485. 0.057 0.029 0.00 2.80 193.80 2512. 0.058 0.029 0.00 2.81 193.81 2521. 0.058 0.029 0.00 2.82 193.82 2530. 0.058 0.030 0.00 2.83 193.83 `2539. 0.058 0.031 0.00 2.84 193.84 2548. 0.058 0.032 0.00 2.85 193.85 2557. 0.059 0.032 0.00 2.86 193.86 2565. 0.059 0.032 0.00 2.96 193.96 2655. 0.061 0.035 0.00 3.06 194.06 2745. 0.063 0.037 0.00 3.16 194.16 2835. 0.065 0.039 0.00 3.26 194.26 2924. 0.067 0.040 0.00 3.36 194.36 3014. 0.069 0.041 0.00 3.46 194.46 3104. 0.071 0.043 0.00 3.56 194.56 3193. 0.073 0.044 0.00 3.66 194.66 3283. 0:075 0.045 0.00 3.76 194.76 3373. 0.077 0.046 0.00 3.86 194.86 3462. 0.079 0.047 0.00 3.96 194.96 3552. 0.082 0.048 0.00 4.00 195.00 3588. 0.082 0.049 0.00 4.10 195.10 3678. 0.084 0.358 0.00 Technical Information Report (TIR) 05-251 -2006 IMEDINA ProjectsIHirai SPIEngineering n2Didd Consulting Engineers. Inc. Stage Elevation Storage Discharge Percolation (ft) (ft) (cu. ft) (ac -ft) (cfs) (cfs) 4.20 195.20 3767. 0.086 4.30 195.30 3857. 0.089 4.40 195.40 3947. 0.091 4.50 195.50 4037. 0.093 4.60 195.60 4126. 0.095 4.70 195.70 4216. 0.097 4.80 195.80 4306. 0.099 4.90 195.90 4395. 0.101 5.00 196.00 4485. 0.103 5.10 196.10 4575. 0.105 5.20 196.20 4664. 0.107 5.30 196.30 4754. 0.109 5.40 196.40 4844. 0.111 5.50 196.50 4934. 0.113 5.60 196.60 5023. 0.115 5.70 196.70 5113. 0.117 5.80 196.80 5203. 0.119 5.90 196.90 5292. 0.121 6.00 197.00 5382. 0.124 Hyd Inflow Outflow Peak Target Calc Stage Elev 0.922 1.650 2.440 2.730 2.980 3.220 3.440 3.650 3.840 4.030 4.200 4.370 4.540 4.690 4.850 4.990 5.140 5.280 5.410 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Storage (Cu -Ft) (Ac -Ft) 1 0.24 2 0.12 3 0.12 4 0.12 5 0.14 6 0.07 7 0.09 8 0.10 * * * * * ** 0.05 * * * * * ** * * * * * ** 0.03 * * * * * ** * * * * * ** 0.21 0.08 0.05 0.05 0.04 0.03 0.02 0.02 4.05 4.01 3.98 3.75 3.41 2.41 1.38 1.16 Route Time Series through Facility Inflow Time Series File: dev.tsf Outflow Time Series File: rdout Inflow /Outflow Analysis Peak Inflow Discharge: Peak Outflow Discharge: Peak Reservoir Stage: Peak Reservoir Elev: Peak Reservoir Storage: 195.05 195.01 194.98 194.75 194.41 193.41 192.38 192.16 0.239 CFS at 0.208 CFS at 4.05 Ft 195.05 Ft 3634.0 Cu -Ft 0.083 Ac -Ft 3634. 3596. 3570. 3368. 3055. 2161. 1238. 1040. 0.083 0.083 0.082 0.077 0.070 0.050 0.028 0.024 6:00 on Jan 9 in Year 8 9:00 on Jan 9 in Year 8 Technical Information Report (TIR) 05-251 -2006 17 Dind Consulting Engineers. Inc. IMEDINA ProjectsVHirai SPIEngineering Flow Frequency Analysis Time Series File: rdout.tsf Project Location: Sea -Tac - -- Annual Peak Flow Rate Rank (CFS) Flow Rates-- - Time of Peak Flow Frequency Analysis - - Peaks - - Rank Return Prob (CFS) (ft) Period 0.077 2 0.020 7 0.042 5 0.019 8 0.027 6 0.046 4 0.048 3 0.208 1 Computed Peaks 2/09/01 12/28/01 2/28/03 8/24/04 1/05/05 1/18/06 11/24/06 1/09/08 16:00 1.7:00 7:00 0:00 15:00 22:00 7:00 9:00 0.208 0.077 0.048 0.046 0.042 0.027 0.020 0.019 0.165 4.05 4.01 3.98 3.75 3.41 2.41 1.38 1.16 4.04 1 100.00 2 25.00 3 10.00 4 5.00 5 3.00 6 2.00 7 1.30 8 1.10 50.00 0.990 0.960 0.900 0.800 0.667 0.500 0.231 0.091 0.980 Check for Required Storage Volume: Required Peak Storage Volume = 3,634.0 CF, add 10% volume increase factor b Required Peak Storage Volume = 3,998.0 C.F. Provided Storage Volume = 52' X 5' X 17.25' = 4,485.0 CF > 3,998.0 CF, OK. Please see next page for the vault performance graph, and the attached Details for the Combined Wet -R /D Vault. oOo Technical Information Report (TIR) 05- 251 -2006 MEDi MI Consulting Engineers. Inc. IMEDINA ProjectsVlirai SPIEngineering Return Period 2 1 5 1 101 201 501 109 Discharge (CFS) o rdout.pks in Sea -Tac • PREDEV.pks tn- - o 101 I 10 -2 in- 103 0 • 0 00 • 0 R • a • • 1 2 5 10 20 30 40 50 60 70 80 90 95 98 99 Cumulative Probability HIRAI DEVELOPMENT May . 25,'06 JOB NO. MCE- 010706 -01' WATER QUALITY - WETPOOL- DESIGN CALCULATOINS 1 1 1 1 I l 1998 KCSWDM STEP 1: IDENTIFY REQUIRED WETPOOL VOLUME FACTOR (f) f= 3 STEP 2: DETERMINE RAINFALL (R) FOR THE MEAN ANNUAL STROM R = 0.47 IN STEP 3: RUNOFF FROM THE MEAN ANNUAL STORM (V,) FOR THE DEVELOPED SITE A, = 15,682 SF IMPERVIOUS Ate = 14,244 SF TILL GRASS At, = 0 SF TILL FOREST Ao = 0 SF OUTWASH 29926 SF TOTAL AREA V, = (0.9A; + 0.25Atg + 0.10A,t + 0.01A0) x (R / 12) Eq. 6 -13 V, = 692 CF STEP 4: WETPOOL VOLUME NO Vb = f V, Eq. 6 -14 Vb = 2,077 CF Check Provided Wet Volume: 4' X52'X17.25'= 3,588CF >Vb= 2077CFOK 1 CeII (1) Volume = 15' X 4' X 17.25' = 1,035 CF = 0.29 % of Total Provided Wet -Pool Volume, OK • = St.d 48" Dia. Lockng Open Grate (TYP.) A Ventilation pipe " min.) (TYR.) R 15' \ . Removable Baffle V" shaped bottom (----'1 / 1 LO Ladder . ttin 2 0 R 52' length P L A \ \117 A IN PLOW • • • • • Gontro Structure = frame, grate and locking cover marked drain (typ.) 7:1111V11 UijjI Outlet 12" CPFT EL = 191,C =MEI I finished Grace 4' Active cet.entioni • removable 17;affle Rim = 202.0 frame, grate and locking cover marked drain (typ2.) .111-1T-115_11 I 7 4.0' Wet.2ool bottom slope 2% towards outlet end of second cell (recommended) SECTION A-A • NTS EL = 95.0 net 12" CPEP — 190.0 Bottom s ope 2% toward inlet end Average sediment storage 1' min. (first cell) rinsned Grade =111=1117 EL = 196.0 11 • • 4 Access Manha:e • • ,;4 • wQ 1ITT_TIEFE-,1117 11-,5-1_111-11_17 =7' • 5 (min.) slope rowel finish SECTIO\ NTS Average 1' sediment storage (first eel.) CN Top of Riser 12" EL =195.0 f EL =193.8 P MISER • 4.0' shear gate CMP Orifice No. 2 (0.69" dia) EL =191.0 (N; L Orifice No. 1 (0.8" dia) EL =189.0 ()I. 11 -q f_{a 1 1 ' I' ./ T _; NO SCALE Section 5 CONVEYANCE CAPACITY ANALYSES Technical Information Report (TIR) 05-251 -2006 MEDUSA Consulting Engineers. Inc. IMEDINA ProjectslHirai SPIEngineering Conveyance Capacity Calculations: The proposed on -site 12" CPEP conveyance system 100 -year capacity was checked using the Flow Mater program for the minimum pipe slope of 1.74 %, this shows the pipe capacity is more that adequate to convey the 100 -yr flows in the developed conditions. The below calculations will show that flow depth is less than 25 % for a 12 -in at 1.741%. The developed Peak Runoff Calculations Based on 15 — minute b Q100 = 0.59 c.f.s. KCRTS Command CREATE a new Time Series Production of Runoff Time Series Project Location: Sea -Tac Computing Series: DevConveyance.tsf Regional Scale Factor: 1.00 Data Type: Reduced Creating 15- minute Time Series File Loading Time Series File :C: \KC_SWDM \KC_DATA \STTG15R.rnf : Till Grass 0.33 acres Loading Time Series File :C: \KC_SWDM \KC_DATA \STEI15R.rnf : Impervious 0.36 acres Total Area: 0.69 acres Flow Frequency Analysis Time Series File: Devconveyance.tsf Project Location: Sea -Tac - -- Annual Peak Flow Rates-- - Flow Rate Rank Time of Peak (CFS) Flow Frequency Analysis - - Peaks - - Rank Return Prob. (CFS) Period 0.172 0.128 0.396 0.138 0.249 0.213 0.244 0.590 Computed Peaks 6 8/27/01 8 1/05/02 2 12/08/02 7 8/23/04 3 11/17/04 5 10/27/05 4 10/25/06 1 1/09/08 18:00 15:00 17:15 14:30 5:00 10:45 22:45 6:30 0.590 0.396 0.249 0.244 0.213 0.172 0.138 0.128 0.525 1 100.00 2 25.00 3 10.00 4 5.00 5 3.00 6 2.00 7 1.30 8 1.10 50.00 0.990 0.960 0.900 0.800 0.667 0.500 0.231 0.091 0.980 Technical Information Report (TIR) 05-251 -2006 MEDind Consulting Engineers, Inc. IMEDINA Projects1Hirai SPIEngineenng Project Description Worksheet Circular Channel -1 Flow Element Circular Channel Method Manning's Formula Solve For Discharge Input Data Mannings Coefficient 0.012 Channel Slope 0.017400 ft/ft Depth 1.00 ft Diameter 12.0 in Results Discharge 5.09 cfs Flow Area 0.8 ft' Wetted Perimeter 3.14 ft Top Width 0.00 ft Critical Depth 0.92 ft Percent Full 100.0 % Critical Slope 0.015095 ft/ft Velocity 6.48 ft/s Velocity Head 0.65 ft Specific Energy 1.65 ft Froude Number 0.00 Maximum Discharge 5.48 cfs Discharge Full 5.09 cfs Slope Full 0.017400 ft/ft Flow Type Subcritical Check for Depth Flow @ Q100 = 0.59 c.f.s. v Project Description Worksheet Circular Channel - 1 Flow Element Circular Channel Method Manning's Formula Solve For Channel Depth Input Data Mannings Coefficient 0.012 Channel Slope 0.017400 ft/ft Diameter 12.0 in Discharge 0.59 cfs Technical Information Report (TIR) 05- 251 -2006 IMEDINA ProjectsWirai SPIEngineenng mEDind Consulting Engineers. Inc.. Results Depth Flow Area Wetted Perimeter Top Width Critical Depth Percent Full Critical Slope Velocity Velocity Head Specific Energy Froude Number Maximum Discharge Discharge Full Slope Full Flow Type 0.23 ft 0.1 ft2 1.00 ft 0.00 ft 0.32 ft 23.0 % 0.004789 ft/ft 4.33 ftls 0.29 ft 0.52 ft 1.90 5.48 cfs 5.09 cfs 0.000234 ft/ft Supercritical oOo 12.0 in 0.23 ft V: 1 N H:1 N TS Technical Information Report (TIR) 05-251 -2006 17EDi/1.d Consulting Engineers. Inc. IMEDINA ProjectslHirai SPIEngineering Section 6 SPECAIL REPORTS AND STUDIES Technical Information Report (TIR) 05-251 -2006 MEDD7d Consulting Engineers, Inc. IMEDINA ProjectsVRirai SPIEngineering Special Reports and Studies: See attached Geotechnical Report by Nelson Geotechnical dated March 30, 2006. o0o Technical Information Report (TIR) 05-251 -2006 nEDi/7d •Consulting Engineers. Inc. IMEDINA ProjectslHirai SPIEngineenng NELSON GEOTECHNICAL N GA ASSOCIATES, INC. GEOTECMIViCAL ENGINEERS &GEOLOGISTS GEOTECHNICAL ENGINEERING EVALUATION HIRAI SHORT PLAT TUKWILA, WASHINGTON PREPARED FOR MR. GEORGE HIRAI NGA 17311 —135'" Avenue NE, A -500 Woodinville, WA 98072 (425) 486 -1669 • (425) Fax 481 -2510 March 30, 2006 Mr. George Hirai 1561562 "d CT NE Redmond, Washington 98052 NELSON GEOTECHNICAL ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington NGA File No. 733906 Dear Mr. Hirai: Snohomish County (425) 337 -1669 Wenatchee/Chelan (509) 784-2756 We are pleased to submit the attached report titled "Geotechnical Engineering Evaluation — Hirai Short Plat — Tukwila, Washington." This report summarizes the existing surface and subsurface conditions within the site and provides general recommendations for the proposed site development. Our services were completed in general accordance with the proposal signed by you on February 23, 2006. Project plans include the development of five single - family residential lots with associated pavement and utilities. The majority of the site slopes gently to the east, with steeper grades located directly above an existing rockery retaining wall which is located at the bottom of the slope, just off the eastern site boundary. We understand that stormwater management plans will include either a detention vault or detention pipes. We monitored the excavation of eight test pits in the planned development area to depths of up to 10 feet below the existing ground surface. These explorations encountered a surficial layer of topsoil and undocumented fill underlain by competent stiff silt with trace sand. We have concluded that the site is generally compatible with the planned development. We have recommended that the new structures be founded on the medium stiff or better native soil for bearing capacity and settlement considerations. These soils should generally be encountered approximately two feet below the existing ground surface, based on our explorations. The silty soils encountered in our explorations have a relatively low permeability and are not considered suitable for on -site infiltration. We understand that an underground detention vault or pipe will be utilized for stormwater management on this project. We have included preliminary recommendations for design and excavation of an underground detention vault. However, if the vault will be located in an unexplored area of the site, or if the vault excavation is to extend past the depths explored, additional explorations in the area of the vault may be required prior to construction, to confirm that the subsurface conditions are consistent with our design recommendations. In the attached report we have also included recommendations for site grading, temporary slopes, and retaining walls. The on -site soils are considered extremely moisture sensitive. We strongly recommend that construction take place during the dryer summer months and suspended during periods of rain. Recommendations for Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Summary - Page 2 erosion control and site preparation and grading have been included in the attached report. Also, our recommendations for erosion control and site grading should be strictly followed. It has been a pleasure to provide service to you on this project. Please contact us if you have any questions regarding this report or require further information. Sincerely, NELSON GEOTECHNICAL ASSOCIATES, INC. One Copy Submitted cc: Mr. Mazen Haidar — Medina Consulting Engineers, Inc. (Three copies) TABLE OF CONTENTS INTRODUCTION 1 SCOPE 1 SITE CONDITIONS 2 SURFACE CONDITIONS 2 SUBSURFACE CONDITIONS 2 HYDROLOGIC CONDITIONS 3 LABORATORY ANALYSIS 3 SENSITIVE AREA EVALUATION 4 SEISMIC HAZARD 4 EROSION HAZARD 4 LANDSLIDE HAZARD /SLOPE STABILITY 4 CONCLUSIONS AND RECOMMENDATIONS 5 GENERAL 5 EROSION CONTROL 6 TEMPORARY AND PERMANENT SLOPES 7 SITE PREPARATION AND GRADING 8 FOUNDATIONS 9 STRUCTURAL FILL 10 SLAB -ON -GRADE 11 PAVEMENTS 11 STORMWATER MANAGEMENT 12 RETAINING WALLS 12 SITE DRAINAGE 14 USE OF THIS REPORT 14 LIST OF FIGURES Figure 1 — Vicinity Map Figure 2 — Site Plan Figure 3 — Cross Sections A -A' Figure 4 — Cross Sections B -B' Figure 5 — Cross Sections C -C' Figure 6 — Soil Classification Chart Figures 7 and 8 — Test Pit Logs Figures 9 and 10 — Sieve Analysis NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington INTRODUCTION This report presents the results of our geotechnical engineering investigation and evaluation of the Hirai Short Plat project in Tukwila, Washington. The site is located at the northwest corner of the intersection of South 132nd Street and Pacific Hwy South, as shown on the Vicinity Map in Figure 1. The purpose of this study is to explore and characterize the site's surface and subsurface conditions, and to provide geotechnical recommendations for site development. For our use in preparing this report, we were provided with an undated site plan titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc., showing the existing site topography and the planned lot layout. Project plans include developing this 0.58 -acre site into five single - family residential lots with associated pavement and utilities. Daylight basement retaining walls may be incorporated into some of the structures constructed on mildly sloping ground. Stormwater management plans will likely consist of on- site detention, via either a vault or pipes. The proposed lot alignments and existing topography are shown on the Site Plan in Figure 2. SCOPE The purpose of this study is to explore and characterize the site subsurface conditions, and provide general recommendations for site development. Specifically, our scope of services includes the following: 1. Review available soils and geologic maps of the area. 2. Explore the subsurface soil and groundwater conditions within the site with trackhoe- excavated test pits. Trackhoe was subcontracted by NGA. 3. Map the surficial slope conditions and produce cross - sections. 4. Perform grain -size sieve analysis on soil samples. 5. Provide our opinion regarding slope stability. 6. Provide recommendations for earthwork, foundation support, and slabs -on- grade. 7. Provide recommendations for subgrade preparation and pavements. 8. Provide recommendations for site drainage and erosion control. 9. Document the results of our findings, conclusions, and recommendations in a written geotechnical report. NELSON GEOTECHN/CAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 2 SITE CONDITIONS Surface Conditions The property is an irregularly shaped parcel covering approximately 0.58 acres. The property is bordered to the north and west by developed residential property, to the east by Pacific Hwy South, and to the south by South 132nd Street. The site slopes gently down toward the eastern property line, where the slope then becomes moderate to steep over a vertical relief of less than 10 feet, buttressed by a 3.5 -to 8.0 -foot high rockery retaining wall. Profiles of the existing ground surface and the interpretive subsurface conditions are shown on Cross Sections A -A', B -B', and C -C', in Figures 3 through 5, respectively. Access to the property is currently from a gravel driveway off South 132nd Street along the southwest corner of the site. The site is currently undeveloped, covered with grass, blackberries, and a few conifer and fruit trees. The northeast corner of the site in particular is heavily vegetated. We observed ponding water within the site during our site visit on March 15, 2006. This water appeared to be collecting on the surface of a previously graded building pad, where a structure was likely located in the past. The approximate location of the ponding water is shown on the Site Plan, Figure 2. Subsurface Conditions Geology: The geologic units forr this area are shown on the Preliminary Geologic Map of Seattle and Vicinity, Washington, by Howard H. Waldron, Bruce A. Liesch, Donald R. Mullineaux, and Dwight R. Crandell (U.S.G.S., 1962). The site is mapped as Vashon till (Qt), and the area just east of the site is mapped as undifferentiated deposits of the Pleistocene age (Qu). The till is described as a nonsorted mixture of clay, silt, sand, pebbles, cobbles, and boulders. Our explorations generally encountered glacially consolidated silt with trace fine sand. We interpreted this material to be an interglacial deposit, likely consolidated during the Vashon age glaciation. Explorations: The subsurface conditions within the site were explored on March 15, 2006 by excavating eight test pits to depths ranging from 2.0 to 11.0 feet below the existing ground surface using a trackhoe. The approximate locations of our explorations are shown on the Site Plan in Figure 2. An engineer from NGA was present during the explorations, examined the soils and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the test pits. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 3 The soils were visually classified in general accordance with the Unified Soil Classification System, presented in Figure 6. The logs of our test pits are attached to this report and are presented as Figures 7 and 8. We present a brief summary of the subsurface conditions in the following paragraph. For a detailed description of the subsurface conditions, the logs of the test pits should be reviewed. Test Pits 2, 4, and 8 exposed a 1.3 -to 2.0 -foot thick layer of dark brown to black silt with trace fine sand and roots, which was interpreted as topsoil/modified ground. Test pits 1, 3, and 5 through 7 exposed a 1.0 -to 2.8 -foot thick surficial layer of dark brown silt with trace fine sand, roots, bricks, and other miscellaneous rubble. We interpreted this material to be undocumented fill. Underlying the topsoil and fill, our explorations exposed stiff to very stiff, brown -gray to blue -gray silt with trace fine sand extending to the bottom of the explorations. We interpreted this material to be native glacially consolidated material. Hydrologic Conditions Groundwater seepage was not encountered in any of our explorations, however, we would expect that a perched groundwater condition may develop on this site during the wet season. Perched water occurs when surface water infiltrates through less dense, more permeable soils, such as topsoil and fill, and accumulates on top of a relatively impermeable material, such as the very stiff to stiff native silt soils. Perched water does not represent a regional groundwater "table" within the upper soil horizons. Perched water tends to vary spatially and is dependent upon the amount of rainfall. We would expect the amount of groundwater to decrease during drier times of the year and increase during wetter periods. LABORATORY ANALYSIS We performed two grain -size analyses on selected soil samples obtained from the explorations, located in the central section of the development area, as shown on the Site Plan in Figure 2. The results of the sieve analyses are presented as Figures 9 and 10. The analyses indicated that the soils underlying the site are predominately composed of silt. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 4 SENSITIVE AREA EVALUATION Seismic Hazard We reviewed the 2003 International Building Code (IBC) for seismic site classification for this project. Since very stiff to stiff silt was encountered underlying the site at depth, the site conditions best fit the IBC description for Site Class D. Hazards associated with seismic activity include liquefaction potential and amplification of ground motion. Liquefaction is caused by a rise in pore pressures in a loose, fine sand deposit beneath the groundwater table. It is our opinion that the competent glacially consolidated deposits interpreted to underlie the site have a low potential for liquefaction or amplification of ground motion. Erosion Hazard The criteria used for determination of the erosion hazard for affected areas include soil type, slope gradient, vegetation cover, and groundwater conditions. The erosion sensitivity is related to vegetative cover and the specific surface soil types, which are related to the underlying geologic soil units. The Soil Survey of King County Area, Washington by the Soil Conservation Service (SCS) was reviewed to determine the erosion hazard of the on -site soils. The site was mapped just beyond the boundaries of the Soil Survey; however, the surface soils are closely associated with the mapping unit of Kitsap Silt loam, 8 to 15 percent slopes. The erosion hazard for this material is listed as moderate to severe. It is our opinion that the erosion hazard for site soils should be low in areas where vegetation is maintained, and severe in areas of exposed silt. Landslide Hazard/Slope Stability The criteria used for evaluation of landslide hazards include soil type, slope gradient, and groundwater conditions. The overall site inclinations are gentle to moderate, however, a slope below the five residential lots has inclinations of up to 30 degrees, with a vertical relief of less than 10 feet. This slope is buttressed by a 3.5 -to 8.0 -foot high rockery retaining wall. The core of the site slope is inferred to consist of stiff to very stiff glacially consolidated silt. Relatively shallow failures as well as surficial erosion are natural processes and could be expected on the slope below the site during severe rainstorms. However, these processes would be limited through the NELSON GEOTECHN /CAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 5 maintenance of a vegetative cover and proper stormwater management. It is our opinion that there is not a significant potential for deep- seated slope failure under current site conditions. Proper site grading and drainage as well as vegetation management as recommended in this report should help maintain current stability conditions. Also, the recommended effective structure setback should reduce the potential adverse impacts of site development on the slope and vice versa. CONCLUSIONS AND RECOMMENDATIONS General It is our opinion from a geotechnical standpoint that the site is compatible with the planned development. Our explorations indicated that the planned development area is generally underlain by a one -to three -foot thick surficial layer of very soft topsoil and fill, underlain by competent silt deposits. The medium stiff or better native soils should provide adequate support for the planned structures and roadways. We recommend that the structures be designed utilizing shallow foundations. Footings should extend through any undocumented fill, or loose materials, and be founded on the underlying medium stiff or better native soils or structural fill extending to these soils. Our explorations generally encountered medium stiff or better native soils at depths of two feet below the existing ground surface. Adequate structure setbacks should be maintained in relationship to the locally steep sloping ground and rockery retaining wall. To protect the existing slope and rockery from development, we recommend that the downhill structure footing lines be set back at least 10 feet from a line drawn at 27 degrees from the horizontal, starting at the base of the rockery and extending upwards into the slope, intersecting the site ground surface above. NGA should be retained to evaluate final structure placement on each lot. Under no circumstances should water be allowed to flow over or concentrate on the steep slope, both during construction and after construction has been completed. The yard areas should be graded to direct runoff away from the top of steep slope, if possible. We recommend that stormwater runoff from the roofs, driveway, footing drains, and yard drains be collected in catch basins and tightlined into an approved stormwater management system. We understand that an underground detention vault or pipe will likely be considered for stormwater management on this project. If the vault will be located in an unexplored area of the site, or will extend to NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 6 a depth below the depths explored, we should observe additional explorations in the area of the planned vault to confirm that the subsurface conditions are consistent with our design recommendations. Grading for the vault should be in accordance with the recommendations found in the Site Preparation and Grading and Temporary and Permanent Slopes subsections of this report. We would expect wet surficial soil conditions during the wetter times of the year We recommend the use of footing drains around structures, and wall drains behind stem/retaining walls. Specific drainage recommendations are given in the Site Drainage subsection of this report. The site soils are considered extremely moisture - sensitive and will disturb easily even in moderately wet conditions. We strongly recommend that construction take place during the drier summer months and suspended during wet periods. If construction is to be attempted in wet conditions, major additional expenses and delays should be expected due to the wet conditions. Additional expenses could include the need for placing a blanket of rock spalls and/or geo- fabric on exposed subgrades, construction traffic areas, and paved areas prior to placing structural fill, and the need for using all- weather material for structural fill. The use of the native on -site soils as structural fill will likely be unfeasible, but will depend on the moisture content of the soil at the time of construction. NGA should be retained to determine if the on -site soils could be used as structural fill material prior to construction. We should also note that major erosion control expenses and delays may be incurred if the site is to be developed in wet weather. Erosion Control The erosion hazard for the on -site soils is considered severe for exposed soils but actual erosion potential will be dependent on how the site is graded and how water is allowed to concentrate. Best Management Practices (BMPs) should be used to control erosion. Areas disturbed during construction should be protected from erosion. Erosion control measures may include covering exposed soils with a layer of crushed rock, diverting surface water away from the stripped or disturbed areas, and limiting construction traffic on prepared subgrades. Silt fences or straw bales should be erected to prevent muddy water from leaving the site. Disturbed areas should be planted as soon as practical and the vegetation should be maintained until it is established. Other erosion control measures may include the use of a temporary sediment control pond or Baker's tanks to store muddy water prior to leaving the site. This can be NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 7 evaluated at the time of construction based on the actual site conditions. The erosion potential of areas not stripped of vegetation should be low. Temporary and Permanent Slopes Temporary cut slope stability is a function of many factors, including the type and consistency of soils, depth of the cut, surcharge Loads adjacent to the excavation, length of time a cut remains open and the presence of surface or groundwater. It is exceedingly difficult under these variable conditions to estimate a stable, temporary, cut slope angle. Therefore, it should be the responsibility of the contractor to maintain safe slope configurations since he is continuously at the job site, able to observe the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater conditions encountered. The following information is provided solely for the benefit of the owner and other design consultants and should not be construed to imply that Nelson Geotechnical Associates, Inc. assumes responsibility for job site safety. Job site safety is the sole responsibility of the project contractor. For planning purposes, we recommend that temporary cuts in any undocumented fill and loose soils be no steeper than 2.0 Horizontal to 1.0 Vertical (2H:1V). Cuts in the native silt could stand at inclinations as steep as 1H: 1V. If significant groundwater seepage is encountered, we would expect that flatter inclinations would be necessary. We recommend that cut slopes be protected from erosion. These erosion protection measures may include covering cut slopes with plastic sheeting and diverting surface runoff away from the top of cut slopes. We do not recommend vertical slopes for cuts deeper than four feet, if worker access is necessary. We recommend that cut slope heights and inclinations conform to appropriate OSHAJWISHA regulations. We recommend that permanent cuts in the native silt, as well as any permanent fill slopes to be constructed on site be no steeper than 2.0 unit Horizontal to 1.0 unit Vertical (2.0H:1V). We recommend that permanent cut and fill slopes be protected from erosion. Vegetation should be planted on permanent slopes and maintained until established. To reduce the potential for erosion, surface water runoff should not be allowed to flow uncontrolled over the permanent slopes. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 8 Site Preparation and Grading After erosion control measures are implemented, site preparation should consist of stripping the development areas of organics, any fill, and loose soils to expose medium stiff or better native soils for the structural fill subgrade, and in foundation, slab, and pavement areas. Our explorations generally encountered medium stiff or better native soils at depths of two feet below the existing ground surface. However, additional stripping may be required in unexplored areas of the site or if the exposed subgrade becomes disturbed due to wet weather. The stripped materials should be removed from the site or stockpiled for later use as landscaping fill. If the stripped material is to be stockpiled on site, the stockpiles should be kept away from the steeper portions of the slope and covered with plastic at all times. We recommend that any undocumented fill encountered in the structure and pavement areas be removed and replaced with structural fill or rock spalls extending to competent native material. Depending on subgrade and weather conditions, pavement and slab subgrade should be compacted to a non - yielding condition using static rollers then proof - rolled with a heavy rubber -tired piece of equipment. Areas observed to pump or weave during the proof -roll test should be reworked to structural fill specifications or over - excavated and replaced with properly compacted structural fill or rock spalls. For better pavement and slab -on -grade performance, especially in wet conditions, a one -foot thick layer of crushed rock may be placed over the prepared subgrade prior to placing asphalt or concrete. Final subgrade preparation recommendations can be provided at the time of construction. If significant surface water flow is encountered during construction, this flow should be diverted around areas to be developed and the exposed subgrade maintained in a semi -dry condition. If wet conditions are encountered, alternative site stripping and grading techniques will be necessary due to the highly sensitive nature of the site soils. These methods could include using large excavators equipped with wide tracks and a smooth bucket to complete site grading and covering exposed subgrade with a layer of crushed rock for protection. If wet conditions are encountered or construction is attempted in wet weather, the subgrade should not be compacted as this could cause further subgrade disturbance. In wet conditions it may be necessary to cover the exposed subgrade with a layer of crushed rock as soon as it is exposed to protect the moisture sensitive soils from disturbance by machine or foot traffic during construction. The prepared subgrade should be protected from construction traffic and surface water should be diverted around prepared subgrade. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 9 The site soils are considered extremely moisture - sensitive and will disturb easily even in moderately wet conditions. We strongly recommend that construction take place during the drier summer months. If construction takes place during the wet season, additional expenses and delays should be expected due to the wet conditions. This may include the need for installing an interceptor drain along the uphill side of the site. Additional expenses could also include the need for placing a blanket of rock spalls and/or geo- fabric on exposed subgrades, construction traffic areas, and paved areas prior to placing structural fill. The use of on -site soils as structural fill will likely be unfeasible, but will be highly dependent on the moisture content of the soil at the time of construction. NGA should be retained to determine if the on- site soils could be used as structural fill material at the time of construction. For planning purposes, the use of the on -site material as structural fill should be considered unfeasible. Foundations Conventional shallow spread foundations should be placed on undisturbed medium stiff or better native soils or be supported on structural fill extending to those soils. Where undocumented fill or less dense soils are encountered at the planned footing elevation, the subgrade should be over - excavated to expose suitable bearing soil. The over - excavation may be filled with structural fill, or the footing may be extended down to the native bearing soils. If footings are supported on structural fill, the fill zone should extend outside the edges of the footing a distance equal to one -half of the depth of the over - excavation below the bottom of the footing. Footings, including interior footings, should extend at least 18 inches below the lowest adjacent finished ground surface for frost protection and bearing capacity considerations. Foundations should be designed in accordance with the 2003 IBC. Footing widths should be based on the anticipated loads and allowable soil bearing pressure. Standing water should not be allowed to accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavation prior to placing concrete. It might be prudent to place a layer of crushed rock on prepared foundation subgrade to limit subgrade disturbance by foot traffic. For foundations constructed as outlined above, we recommend an allowable design bearing pressure of not more than 2,000 pounds per square foot (psf) be used for the design of foundations supported on the medium stiff or better native soils or structural fill extending to the competent native soils. A representative of NGA should evaluate the foundation bearing soil. We should be consulted if higher NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat \.1c" Tukwila, Washington 1r.1 March 30, 2006 �r NGA File No. 733906 Page 10 bearing pressures are needed. Current IBC guidelines should. be used when considering increased allowable bearing pressure for short-term transitory wind or seismic loads. Potential foundation settlement using the recommended allowable bearing pressure is estimated to be less than one -inch total and '/ -inch differential between adjacent footings or across a distance of about 20 feet based on our experience with similar projects. Lateral loads may be resisted by friction on the base of the footing and passive resistance against the subsurface portions of the foundation. A coefficient of friction of 0.30 may be used to calculate the base friction and should be applied to the vertical dead load only. Passive resistance may be calculated as a triangular equivalent fluid pressure distribution. An equivalent fluid density of 200 pounds per cubic foot (pcf) should be used for passive resistance design for a level ground surface adjacent to the footing. This level surface should extend a distance equal to at least three times the footing depth. These recommended values incorporate safety factors of 1.5 and 2.0 applied to the estimated ultimate values for frictional and passive resistance, respectively. To achieve this value of passive resistance, the foundations should be poured "neat" against the native medium dense /stiff soils or compacted fill should be used as backfill against the front of the footing. We recommend that the upper one -foot of soil be neglected when calculating the passive resistance. Structural Fill General: Fill placed beneath foundations, pavement, or other settlement- sensitive structures should be placed as structural fill. Structural fill, by definition, is placed in accordance with prescribed methods and standards, and is monitored by an experienced geotechnical professional or soils technician. Field monitoring procedures would include the performance of a representative number of in -place density tests to document the attainment of the desired degree of relative compaction. The area to receive the fill should be suitably prepared as described in the Site Preparation and Grading subsection prior to beginning fill placement. Materials: Structural fill should consist of a good quality, granular soil, free of organics and other deleterious material and be well graded to a maximum size of about three inches. All - weather fill should contain no more than five- percent fines (soil finer than U.S. No. 200 sieve, based on that fraction passing the U.S. 3/4 -inch sieve). The use of on -site soils as structural fill will likely be unfeasible, but will be NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 11 highly dependent on the moisture content of the material at the time of construction. Most of the on -site soils will be virtually impossible to compact to structural fill specifications in wet conditions. We should be retained to evaluate proposed structural fill materials prior to construction. Fill Placement: Following subgrade preparation, placement of structural fill may proceed. All filling should be accomplished in uniform lifts up to eight inches thick. Each lift should be spread evenly and be thoroughly compacted prior to placement of subsequent lifts. All structural fill underlying building areas and pavement subgrade should be compacted to a minimum of 95 percent of its maximum dry density. Maximum dry density, in this report, refers to that density as determined by the ASTM D -1557 Compaction Test procedure. The moisture content of the soils to be compacted should be within about two percent of optimum so that a readily compactable condition exists. It may be necessary to over - excavate and remove wet soils in cases where drying to a compactable condition is not feasible. All compaction should be accomplished by equipment of a type and size sufficient to attain the desired degree of compaction. Slab -on -Grade Slabs -on- grade, if used, should be supported on subgrade soils prepared, as described in the Site Preparation and Grading subsection of this report. We recommend that all floor slabs be underlain by at least six inches of free - draining sand or gravel for use as a capillary break. We recommend that the capillary break be hydraulically connected to the footing drain system to allow free drainage from under the slab. A suitable vapor barrier, such as heavy plastic sheeting (6 -mil minimum), should be placed over the capillary break material. Pavements Pavement subgrade preparation, and structural filling where required, should be completed as recommended in the Site Preparation and Grading and Structural Fill subsections of this report. Any undocumented fill should be removed and replaced with structural fill or thoroughly compacted prior to placing the pavement section. The pavement subgrade should be proof - rolled with a heavy, rubber -tired piece of equipment, to identify soft or yielding areas that require repair. The ability to leave some of the undocumented fill in the payment subgrade will be dependent on the nature of the fill and expected NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 12 pavement performance. We should be retained to evaluate any fill to be left in pavement areas, observe the proof - rolling, and recommend repairs prior to placement of the asphalt or hard surfaces. Stormwater Management The soils exposed in our explorations on this site consisted of silt with trace fine sand. These soils have extremely low permeability and are not considered suitable for stormwater infiltration. A detention vault or pipe may provide a more practical alternative for stormwater management on this site. The possible location of a detention vault for this project had not been established at the time that this report was prepared. Preliminary recommendations for excavation and retaining walls of an underground vault are included in the following subsections of this report. However, if the vault will be located in an unexplored area of the site, or will extend to a depth below the depths explored, we should observe additional explorations in the area of the planned vault to confirm that the subsurface conditions are consistent with our design recommendations. We understand that stormwater may also be handled using a detention pipe, rather than a detention vault. If a detention pipe is used, the bottom of the trench should be cleared of any loose or sloughing material prior to placing the pipe. The pipe should be underlain by one to two feet of washed rock and surrounded with washed rock at least halfway up the pipe, placed evenly in small lifts on both sides of the pipe. The top of the washed rock fill should be covered with filter fabric (Mirafi 140 N or equivalent) prior to placing native material. We recommend that construction equipment not be operated over the pipe until at least three feet of fill is placed over the pipe, or as recommended by the manufacturer. If native material is used over the washed rock, it should be clear of particles over 3 inches in diameter and be placed in thin lifts (no more than 6 inches in thickness). The fill should be compacted using walk behind vibratory plate compactors. We should be retained to review the layout and design of any detention pipe systems. Retaining Walls Retaining walls may be incorporated into project plans in the form of daylight basement stem -walls for the new structures and for any detention vault. The lateral pressure acting on subsurface retaining walls is dependent on the nature and density of the soil behind the wall, the amount of lateral wall movement which can occur as backfill is placed, wall drainage conditions, the inclination of the backfill, and other NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 13 possible surcharge loads. For walls that are free to yield at the top at least one thousandth of the height of the wall (active condition), soil pressures will be less than if movement is limited by such factors as wall stiffness or bracing (at -rest condition). We recommend that walls supporting horizontal backfill and not subjected to hydrostatic forces be designed using a triangular earth pressure distribution equivalent to that exerted by a fluid with a density of 45 pcf for yielding (active condition) walls, and 65 pcf for non - yielding (at -rest condition) walls. These recommended lateral earth pressures are for a drained granular backfill and are based on the assumption of a horizontal ground surface behind the wall for a distance of at least the subsurface height of the wall, and do not account for surcharge loads. Additional lateral earth pressures should be considered for surcharge loads acting adjacent to subsurface walls and within a distance equal to the subsurface height of the wall. This would include the effects of surcharges such as traffic loads, floor slab and foundation loads, slopes, or other surface loads. Also, hydrostatic and buoyant forces should be included if the walls could not be drained. We could consult with you and your structural engineer regarding additional loads on retaining walls during final design, if needed. The lateral pressures on walls may be resisted by friction between the foundation and subgrade soil, and by passive resistance acting on the below -grade portion of the foundation. Recommendations for frictional and passive resistance to lateral loads are presented in the Foundations subsection of this report. All wall backfill should be well compacted as outlined in the Structural Fill subsection of this report. Care should be taken to prevent the buildup of excess lateral soil pressures, due to over - compaction of the wall backfill. This can be accomplished by placing wall backfill in thin loose lifts and compacting it with small, hand - operated compactors within a distance behind the wall equal to at least one -half the height of the wall. The thickness of the loose lifts should be reduced to accommodate the lower compactive energy of the hand- operated equipment. The recommended level of compaction should still be maintained. Permanent drainage systems should be installed for retaining walls. Recommendations for these systems are found in the Subsurface Drainage subsection of this report. We recommend that we be retained to evaluate the proposed wall drain backfill material and drainage systems. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 14 Site Drainage Surface Drainage: Final site grades should allow for drainage away from the planned structures. We suggest that the finished ground be sloped at a minimum gradient of three percent for a distance of at least 10 feet away from the buildings. Surface water should be collected by permanent catch basins and drain lines, and be discharged into an appropriate discharge system. Water should not be allowed to collect in any area where footings, slabs, or pavements are to be constructed. Surface water generated from paved areas and roof drains should be routed into permanent catch basins and then tightlined into appropriate stormwater facilities. Water should not be allowed to flow over the slopes or adjacent rockery. Subsurface Drainage: If groundwater is encountered during construction, we recommend that the contractor slope the bottom of the excavations and collect the water into ditches and small sump pits where the water can be pumped out and routed to a suitable discharge point. We recommend the use of footing drains around the planned structures and wall drains behind retaining walls. Footing drains should be installed at least one foot below planned finished floor elevation. The drains should consist of a minimum four-inch-diameter, rigid, slotted or perforated, PVC pipe surrounded by free - draining material, such as washed rock, wrapped in a filter fabric. We recommend that an 18- inch -wide zone of clean (less than three - percent fines), granular material be placed along the back of the walls above the drain. Pea gravel is an acceptable drain material or a drainage composite may be used instead. The free - draining material should extend up the wall to one foot below the finished surface. The top foot of backfill should consist of impermeable soil placed over plastic sheeting or building paper to minimize surface water or fines migration into the footing drain. Footing drains should discharge into tightlines leading to an appropriate collection and discharge point with convenient cleanouts to prolong the useful life of the drains. Roof drains should not be connected to footing drains. If a detention vault or pipe is used and these elements can not be effectively drained, they should be designed to withstand hydrostatic forces. USE OF THIS REPORT NGA has prepared this report for Mr. George Hirai,, and his agents, for use in the planning and design of the development planned on this site only. The scope of our work does not include services related to construction safety precautions and our recommendations are not intended to direct the contractors' NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 15 methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. There are possible variations in subsurface conditions between the explorations and also with time. Our report, conclusions, and interpretations should not be construed as a warranty of subsurface conditions. A contingency for unanticipated conditions should be included in the budget and schedule. We recommend that NGA be retained to provide monitoring and consultation services during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork and foundation installation activities comply with contract plans and specifications. We should be contacted a minimum of one week prior to construction activities and could attend pre - construction meetings if requested. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering practices in effect in this area at the time this report was prepared. No'other warranty, expressed or implied, is made. Our observations, findings, and opinions are a means to identify and reduce the inherent risks to the owner. o -O -o NELSON GEOTECHN/CAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 16 It has been a pleasure to provide service to you on this project. If you have any questions or require further information, please call. Sincerely, NELSON GEOTECHNICAL ASSOCIATES, INC. vin A. McCaughan, E1T Senior Staff Engineer Khaled M. Shawish, PE Principal CAM: KMS:lam Ten Figures Attached NELSON GEOTECHNICAL ASSOCIATES, INC. Southern Heigh` ' of �aSS? �I aG, g' 7 N; l N(! N.. .....m ~�7 VICINITY MAP Not to Scale 5120th PI °.; , c v ro v II i A vi ° Allentoiwn , . 4 N dl i ` i , i -'cn ` �. 1 -till l 125tH 127th St g S 13Qth:Pl I S 1 1S(Pl •S182ndS_ S131c! N ti I 133tast 477.1.1'7:- ._• RdS 5 S 13tittiSt, °{ < { a 13901 st ict- ©2006•MapQuest; Inc. Project Number 733906 Tukwila, WA ', , ®2GC6'N�ITEQ Figure 1 Hirai Short Plat Vicinity Map NGA NELSON GEOTECHNICAL ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS Intl -13aa A... NU. A600 a..n.n..n Cpu0.r H(+aa) asr•taaa Womm.n. WA 88072 W. .&CIrWn (30g) 784 -2188 (426)188.1688 / Fax 481.2510 www.nalwngaolo axxn No. Date Revision By 3/20/08 Original ACO Concrete Walkway • �TP -3 . / TP -3 — ■ G Existing Rockery A ■ LEGEND Property Line TP -1 1 Number and Approximate — ■- I A A' Approximate Location L_J of Cross- Section Location of Test Pit Ditch Catch basin 0 40 80 Reference: Site Plan is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. Project Number 733906 Scale: 1 Inch = 40 feet Figure 2 Hirai Short Plat Site Plan NELSON GEOTECHNICAL NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS at GEOLOGISTS 173,4 1.6 A...�B, A.00 W4561 5, WA 08072 (428) 486.1888 / Fax 481-2810 Wru� .&Q,&.n(8'7842768 4 J1&IOngw .00m No. Date Revision By CK 3/20/08 Original ACO CAM a Z • • m (o c V W W (0 0) -u 1 O. 0 Z c 3 cr 0 o s vi co 0) (D3- ao 0 7 Dv D GEOTECHNICAL ENGINEERS & GEOLOGISTS u� P1 ar co to (n o o2 n o Ul Al _n = n Z n r z 0 0 s 0 0 A Southwest 230 — Approximate Elevation (feet) 210 190 170 0 Gravel Alleyway R Fill TP -7 (Projected 15 -ft. Southeast) Fill Concrete Walkway Existing Rockery up to 30° locally A' Northeast — 230 R Stiff • ery silt with trace d r)(0,1 c, e0.4\ • of S'i( OVI 5► Exploration 20 40 60 80 Test Pit Designation — 3 TP -1 Groundwater Level ---) y During Exploration Geologic Contact ---3 ? (approximate) — —? Distance (feet) 100 120 140 160 210 190 170 NOTES: 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 2) Elevations are approximate. o Reference: Cross Section is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. NGADraNng 20061733906 raraucs.dwg • co c V W W CID 0 rn -v 0) 0 Z c 3 v Q 0 w n I z r Z 0 z P1 P1 CO P1 O r 0 O m i Zi Y� rZ 14 a r 61 O oz n0 a la 0)� a Z= nz r z 0 m 0 0 a 8 E B Southwest 220 Approximate Elevation (feet) 200 180 160 — 0 Gravel Alleyway TP -5 Topsoil & Fill B' Existing Rockery Concrete Walkway Stiff to very stiff silt with trace sand TP-4 Exploration Test Pit Designation --) TP -1 Groundwater Level —3 y During Exploration Geologic Contact -3 ? (approximate) 20 40 60 80 —? Distance (feet) 100 120 140 Northeast — 220 200 180 — 160 NOTES: 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 2) Elevations are approximate. Reference: Cross Section is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. NGA Drafting 20061733906 Firat!(S.dwg co L7 V t0 O 0) _0 0 cD 0 Z C 3 cD 1 0 o m ccu. (n o nm c c ' 2 o Z T. �" w S > .. m � r a co to 0 P1 0Z • n„ r m > o ill El 'to 8 n Z • Q r z 0 v >o 0 0 s a iA 0 1< a Southwest 220 — Approximate Elevation (feet) 200 180 C Gravel Alleyway Stiff to very stiff silt with trace sand Existing Rockery Concrete Walkway Northeast -- 220 200 180 160— — 160 11 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 I 1 1 1 1 1 1 1 1 1 I 1 1 1 1 l 1 1 1 1 I 0 20 40 60 80 100 120 Distance (feet) Exploration Test Pit Designation _ TP -1 Groundwater Level --3 y During Exploration Geologic Contact -3 ? (approximate) NOTES: 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 2) Elevations are approximate-.---__ Reference: Cross Section is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. NGA Drafting 2006/733906 HAraVCS.dwg UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP SYMBOL GROUP NAME COARSE - GRAINED SOILS MORE THAN 50 % RETAINED ON NO. 200 SIEVE GRAVEL MORE THAN 50 % OF COARSE FRACTION RETAINED ON NO. 4 SIEVE CLEAN GRAVEL GW WELL - GRADED, FINE TO COARSE GRAVEL GP POORLY - GRADED GRAVEL GRAVEL WITH FINES GM SILTY GRAVEL GC CLAYEY GRAVEL SAND MORE THAN 50 % OF COARSE FRACTION PASSES NO.4 SIEVE CLEAN SAND SW WELL - GRADED SAND, FINE TO COARSE SAND SP POORLY GRADED SAND SAND WITH FINES SM SILTY SAND SC CLAYEY SAND FINE - GRAINED SOILS MORE THAN 50 % PASSES NO. 200 SIEVE SILT AND CLAY LIQUID LIMIT LESS THAN 50 % INORGANIC ML SILT CL CLAY ORGANIC OL ORGANIC SILT, ORGANIC CLAY SILT AND CLAY LIQUID LIMIT 50 % OR MORE INORGANIC MH SILT OF HIGH PLASTICITY, ELASTIC SILT CH CLAY OF HIGH PLASTICITY, FLAT CLAY ORGANIC OH ORGANIC CLAY, ORGANIC SILT NOTES: HIGHLY ORGANIC SOILS PT PEAT 1) Field classification Is based on visual examination of soil In general accordance with ASTM D 2488 -93. 2) Soll classification using laboratory tests is based on ASTM D 2488 -93. 3) Descriptions of soil density or consistency are based on Interpretation of blowcount data, visual appearance of soils, and/or test data. Project Number 733906 SOIL MOISTURE MODIFIERS: Dry - Absence of moisture, dusty, dry to the touch Moist - Damp, but no visible water. Wet - Visible free water or saturated, usually soil Is obtained from below water table Figure 6 Hirai Short Plat Soil Classification Chart NELSON GEOTECHNICAL NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS 172.1.141115111 - ..x.,..10 . �... woomnww,wwoemx w.n.mn.o/ca.wE0 E07116(428)08-1660 / Fa 1814870 www.ndwryw mm No. Date Revision By CK 3/20/08 Original ACO CAM ML DARK BROWN SILT WITH TRACE FINE SAND, ROOTS, BRICK, AND CONCRETE (VERY SOFT, MOIST TO WET) (FILL) ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND (STIFF, MOIST) ML BLUE -GRAY SILT WITH TRACE FINE SAND (VERY STIFF, MOIST) SAMPLES WERE COLLECTED AT 3.0, 4.0, AND 10.6 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 3.2 FEET TEST PIT WAS COMPLETED AT 11.0 FEET ON 3/15/06 DARK BROWN TO BLACK SILT WITH TRACE FINE SAND AND ROOTS (TOPSOIL) ML BROWN -GRAY SILT WITH TRACE FINE SAND (STIFF, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED TEST PIT CAVING WAS NOT ENCOUNTERED TEST PIT WAS COMPLETED AT 2.0 FEET ON 3/15/06 ML DARK BROWN SILT WITH TRACE FINE SAND, TOPSOIL, AND GARBAGE (VERY SOFT, MOIST TO WET) (FILL) ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND (STIFF, MOIST) SAMPLE WAS COLLECTED AT 5.0 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 1.0 FEET TEST PIT WAS COMPLETED AT 5.5 FEET ON 3/15/06 NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 733906 FIGURE 7 DEPTH (FEET) LOG OF EXPLORATION USC SOIL DESCRIPTION / TEST PIT SIX 0.0 -1.5 ML DARK BROWN SILT WITH TRACE FINE SAND, BRICKS, AND GARBAGE (VERY SOFT, MOIST) (FILL) 1.5 -4.5 ML BROWN -GRAY SILT WITH TRACE FINE SAND (STIFF, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED HEAVY TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 1.5 FEET TEST PIT WAS COMPLETED AT 4.5 FEET ON 3/15/06 TEST PIT SEVEN 0.0 -2.8 ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND AND ROOTS (VERY SOFT, MOIST) (FILL) 2.8 - 5.2 ML BROWN -GRAY SILT WITH TRACE FINE TO MEDIUM SAND AND FINE GRAVEL (STIFF, MOIST) SAMPLES WERE COLLECTED AT 1.5 AND 4.5 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 2.8 FEET TEST PIT WAS COMPLETED AT 5.2 FEET ON 3/15/06 TEST PIT EIGHT 0.0 - 2.0 DARK BROWN TO BLACK SILT WITH TRACE FINE SAND AND ROOTS (TOPSOIL) 2.0 - 2.4 ML BROWN -GRAY SILT WITH TRACE FINE SAND (STIFF, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED TEST PIT CAVING WAS NOT ENCOUNTERED TEST PIT WAS COMPLETED AT 2.4 FEET ON 3/15/06 ACO:CAM NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 733906 FIGURE 8 1 c (O ih trg cl3 W 0 Z W GIE7 Za F • r cc to ▪ O W n0 • 5: PI Le 0 c m W un • z fl? -1 a m r z 0 0 m 0 8 0 rA 0 0 E T R:YT 100 90 80 70 60 50 40 30 20 10 0 1000 0 NGADrafting 20081733908 H§80.SIe'es dwg U.S. STANDARD SIEVE SIZE CIP N.P. +0. 40. 40. +0. +0. 40. COBBLES I I I 1 I I H f 100 10 1.0 GRAIN SIZE IN MILLIMETERS GRAVEL SAND 0.1 COARSE I FINE COARSE' MEDIUM I FINE 0.01 SILT OR CLAY 0.001 U.S.C. SYMBOL EXPLORATION NUMBER AML TP -1 SAMPLE DEPTH 9.0 feet SOIL DESCRIPTION SOIL DISTRIBUTION Gray silt with trace fine sand Gravel = 0% Sand = 3% Silt/Clay = 97% ; co c 0 0 N w 0 m Z c cr m z 0 0 0 5. s (3 w 0 m 100 90 80 1- 70 w >-60 m z 50 LL H W 40 U 0 30 20 10 0 1000 U.S. STANDARD SIEVE SIZE do t,0 60 +o• o +oy COBBLES 100 10 1.0 GRAIN SIZE IN MILLIMETERS GRAVEL COARSE 1 FINE SAND COARSEI MEDIUM FINE U.S.C. SYMBOL EXPLORATION NUMBER •ML TP -2 SAMPLE DEPTH 2.5 feet 0.1 0.01 SILT OR CLAY 0.001 SOIL DESCRIPTION SOIL DISTRIBUTION Gray silt Gravel = 0% Sand = 0% Silt/Clay = 100% NGADiafting 20081733908 NitarSleves.dwg Section 7 OTHER PERMITS Technical Information Report (TIR) 05-251 -2006 171E01114 Consulting Engineers. Inc. IMEDINA ProjectsWirai SPIEngineenng Other Permits: The project owners will obtain for a Right -Of -Way Use permit from the City of Tukwila to install drainage improvements in Pacific Highway (99), and will obtain the proper permits from King County Water District No. 49 and Valvue Sewer District for the installation of the proposed water and sanitary systems. The owners will also obtain a Clearing Grading Permit from the City of Tukwila to clear and grade the sites, and for an individual Building Permits to construct proposed homes. o0o Technical Information Report (TIR) 05-251-2006 IMEDINA ProjectsIHirai SPIEngineenng mom Consulting Engineers. Inc. Section 8 TEMPORARY EROSION AND SEDIMENTATION CONTROL (TESC) Technical Information Report (TIR) 05- 251 -2006 REDmd Consulting Engineers. Inc. IMEDINA ProjectslHirei SPIEngineering Temporary Erosion and Sedimentation Control (TESC), The proposed TESC measures during construction will consist of the use of'BMP devices such as Filter Silt Fence, Construction Entrance, and Catch Basin protection inserts. Please refer to the attached Civil Construction Plans for additional information. o0o Technical Information Report (TIR) 05-251 -2006 6ZEDFJI4 Consulting Engineers. Inc. \MEDINA Projects1Hiral SPIEngineering Section 9 BOND QUANTITIES CALCULATIONS Technical Information Report (TIR) 05- 251 -2006 ffiDAW Consulting Engineers, Inc. IMEDINA ProjectslMrat SPIEngineenng Bond Quantities Calculations Work Sheets, The bond quantities calculations work sheets will submitted with the next plans submittal after the completion of the first engineering review by the City of Burien. ouo Technical Information Report (TIR) 05-251 -2006 /7eDA7d Consulting Engineers. Inc. IMEDINA ProjectsIHirai SPIEngineering Section 10 OPERATION AND MAINTENANCE MANUAL Technical Information Report (TIR) 05-251 -2006 file-%7d Consulting Engineers. Inc. IMEDINA ProjectsIHirai SPIEngineenng Operation and Maintenance Manual, The operation and maintenance procedures will be consistent with the 1998 King County Surface Water Design Manual (KCSWDM). Please see the following pages for additional information. oOo Technical Information Report (TIR) 05-251 -2006 MEDInd Consulting Engineers. Inc. IMEOINA ProjectslHirai SPIEngineenng KING COUNTY, WASHINGTON, SURFACE WATER DESIGN MANUAL APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 1 - DETENTION PONDS Maintenance Component Defect Conditions When Maintenance 1s Needed Results Expected When Maintenance Is Performed General Trash & Debris Poisonous Vegetation Pollution Unmowed Grass/ Ground Cover Rodent Holes Insects Tree Growth Side Slopes of Pond Erosion Storage Area Pond Dikes Emergency Overflow /Spillway Sediment Settlements Rock Missing Any trash and debris which exceed 1 cubic foot per 1,000 square feet (this Is about equal to the amount of trash It would take to fill up one standard size office garbage can). In general, there should be no visual evidence of dumping. Any poisonous or nuisance vegetation which may constitute a hazard to County personnel or the public. Oil, gasoline, or other contaminants of one gallon or more a any amount found that could: 1) cause damage to plant, animal, or marine life; 2) constitute a fire hazard; or 3) be flushed downstream during rain storms. If facility is located in private residential area, mowing Is needed when grass exceeds 18 Inches in height. In other areas, the general policy is to make the pond site match adjacent ground cover and terrain as long as there is no interference with the function of the facility. Any evidence of rodent holes if facility is acting as a dam or berm, or any evidence of water piping through dam or berm via rodent holes. When insects such as wasps and homets interfere with maintenance. activities. Tree growth does not allow maintenance access or interferes with maintenance activity (i.e., slope mowing, silt removal, vactoring, or equipment movements). If trees are not interfering with access, leave trees alone. Eroded damage over 2 Inches deep where cause of damage is still present or where there Is potential for continued erosion. Accumulated sediment that exceeds 10% of the designed pond depth. Any part of dike which has settled 4 inches lower than the design elevation. Only one layer of rock exists above native soil in area five square feet or larger, or any exposure of native soil at the top of out flow path of spillway. Rip -rap on inside slopes need not be replaced. Trash and debris cleared from site. No danger of poisonous vegetation where County personnel or the public might normally be. (Coordination with Seattle -King County Health Department) No contaminants present other than a surface film. (Coordination with Seattle/King County Health Department) When mowing is needed, grass/ground cover should be mowed to 2 inches in height. Mowing of selected higher use areas rather than the entire slope may be acceptable for some situations. Rodents destroyed and dam or bens repaired.. (Coordination with Seattle/King County Health Department) Insects destroyed or removed from site. Trees do not hinder maintenance activities. Selectively cultivate trees such as alders for firewood. Slopes should be stabilized by using appropriate erosion control measure(s); e.g., rock reinforcement, planting of grass, compaction. Sediment cleaned out to designed pond shape and depth; pond reseeded If necessary to control erosion. Dike should be built back to the design elevation. Replace rocks to design standards. 1998 Surface Water Design Manual A _1 9/1/98 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 3 - CLOSED DETENTION SYSTEMS (PIPES/TANKS) Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is Performed Storage Area Manhole Catch Basins Plugged Air Vents Debris and Sediment Joints Between Tank/Pipe Section Tank Pipe Bent Out of Shape Cover Not in Place Locking Mechanism Not Working Cover Difficult to Remove Ladder Rungs Unsafe One -half of the cross section of a vent is blocked at any point with debris and sediment Accumulated sediment depth exceeds 10% of the diameter of the storage area for 34 length of storage vault or any point depth exceeds 15% of diameter. Example: 72 -inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than 34 length of tank. Any crack allowing material to be transported into facility Any part of tank/pipe is bent out of shape more than 1'0% of it's design shape Cover Is missing or only partially. in place. Any open manhole requires maintenance. Mechanism cannot be opened by one maintenance person with proper tools. Bolts Into frame have less than 34 inch of thread (may not apply to self - locking lids.) One maintenance person cannot remove lid after applying 801bs of lift. Intent is to keep cover from sealing off access to maintenance. ling County Safety Office and/or maintenance person judges that ladder is unsafe due to missing rungs, misalignment, rust, or cracks. See "Catch Basins' Standards No. 5 Vents free of debris and sediment All sediment and debris removed from storage area. All joint between tank /pipe sections are sealed Tank/ pipe repaired or replaced to design. Manhole is closed. Mechanism opens with proper tools. Cover can be removed and reinstalled by one maintenance person. Ladder meets design standards allows maintenance person safe access. See 'Catch Basins' Standards No. 5 1998 Surface Water Design Manual A _s 9/1/98 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FAMILIES NO. 4 - CONTROL STRUCTURE/FLOW RESTRICTOR Maintenahce Component Defect Condition When Maintenance is Needed Results Expected When Maintenance. Is Performed General Cleanout Gate Orifice Plate Overflow Pipe Manhole Catch Basin Trash and Debris (Includes Sediment) Structural Damage Distance between debris build -up and bottom of orifice plate is Tess than 1 -1/2 feet. Structure Is not securely attached to manhole wall and outlet pipe structure should support at least 1,000 Ibs of up or down pressure. • Structure Is not In upright position (allow up to 10% from plumb). Connections to outlet pipe are not watertight and show signs of rust. Any holes —other than designed holes —in the structure. Damaged or Missing Cleanout gate Is not watertight or is missing. Gate cannot be moved up and down by one maintenance person. Chain leading to gate is missing or damaged. Gate is rusted over 50% of its surface area. Damaged or Missing Control device Is not worldng properly due to missing, out of place, or bent orifice plate. Obstructions Any trash, debris, sediment, or vegetation blocking the plate. Obstructions Any trash or debris blocking (or having the potential of blocking) the overflow pipe. See 'Closed Detention Systems" Standards No. 3 See 'Catch Basins' Standards No. 5 All trash and debris removed. Structure securely attached to wall and outlet pipe. Structure in correct position. Connections to outlet pipe are water tight; structure repaired or replaced and works as designed. Structure has no holes other than designed holes. Gate is watertight and works as designed. Gate moves up and down easily and Is watertight. Chain is in place and works as designed. Gate is repaired or replaced to meet design standards.. Plate Is in place and works as designed. Plate Is free of all obstructions and works as designed. Pipe Is free of all obstructions and works as designed. See 'Closed Detention Systems' Standards No. 3 See 'Catch Basins' Standards No. 5 9/1/98 A _A 1998 Surface Water Design Manual APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. - CATCH BASINS Maintenance Component General Defect Conditions When Maintenance Is Needed Results Expected When Maintenance is performed Trash & Debris (Includes Sediment) Trash or debris of more than 1/2 cubic foot which is located immediately in front of the catch basin opening or is blocking capacity of the basin by more than 10% Trash or debris (In the basin) that exceeds 1/3 the depth from the bottom of basin to invert the lowest basin. pipe Into or out of the basin. No Trash or debris located immediately in front of catch basin opening. No trash or debris in the catch Trash or debris In any inlet or outlet pipe blocking Inlet and outlet pipes free of trash more than 1/3 of its height. or debris. Dead animals or vegetation that could generate odors that could cause complaints or dangerous gases (e.g., methane). Deposits of garbage exceeding 1 cubic foot in volume Structure Damage to Comer of frame extends more than 3/4 inch past Frame and/or Top Slab curb face into the street (If applicable). Cracks In Basin Walls/ Bottom . Top slab has holes larger than 2 square inches or cracks wider than 1/4 inch (intent is to make sure all .material is running into basin): Frame not sitting flush on top slab, i.e., separation of more than 3/4 Inch of the frame from the top slab. Cracks wider than 1/2 inch and longer than 3 feet, any evidence of soil particles entering catch basin through cracks, or maintenance person judges that structure is unsound. Cracks wider than 1/2 inch and longer than 1 foot at the joint of any inlet/ outlet pipe or any evidence of soil particles entering catch basin through cracks. Sediment/ Misalignment ' Basin has settled more than 1 Inch or has rotated more than 2 inches out of alignment. No dead animals or vegetation present within the catch basin. No condition present which would attract or support the breeding of insects or rodents. Frame is even with curb. Top slab is free of holes and cracks. Frame is sitting flush on top slab. Basin replaced or repaired to design standards. No cracks more than 1/4 inch wide at the joint of inlet/outlet pipe. Basin replaced or repaired to design standards. 1998 Surface Water Design Manual A _C 9/1/98 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. - CATCH BASINS (CONTINUED) Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance is performed Fire Hazard Vegetation Pollution Catch Basin Cover Cover Not in Place Ladder Metal Grates (If Applicable) Locking Mechanism Not Working Cover Difficult to Remove Ladder Rungs Unsafe Trash and Debris Presence of chemicals such as natural gas, oil and gasoline. Vegetation growing across and blocking more than 10% of the basin opening. Vegetation growing in inlet/outiet pipe joints that is more than six inches tall and less than six inches apart. Nonflammable chemicals of more than 1/2 cubic foot per three feet of basin length. Cover Is missing or only partially In place. Any open catch basin requires maintenance. Mechanism cannot be opened by on maintenance person with proper tools. Bolts into frame have Tess than 1/2 inch of thread. One maintenance person cannot remove lid after applying 80 lbs. of lift; intent is keep cover from sealing off access to maintenance. Ladder Is unsafe due to missing rungs, misalignment, rust, cracks, or sharp edges. Grate with opening wider than 7/8 inch. • Trash and debris that is blocking more than 20% of grate surface. Damaged or Missing. Grate missing or broken member(s) of the grate. NO. 6 DEBRIS BARRIERS (E.G., TRASH RACKS) No flammable chemicals present. No vegetation blocking opening to basin. No vegetation or root growth present. No pollution present other than surface film. Catch basin cover Is closed Mechanism opens with proper tools. Cover can be removed by one maintenance person. Ladder meets design standards and allows maintenance person safe access. Grate opening meets design standards. Grate free of trash and debris. Grate is in place and meets design standards. Maintenance Components Defect Condition When Maintenance is Needed Results EXpe ted When Maintenance is Performed. General Metal Trash and Debris Damaged/ Missing Bars. Trash or debris that is plugging more than 20% of the Barrier clear to receive capacity openings in the barrier. flow. Bars are bent out of shape more than 3 Inches. Bars in place with no bends more than 3/4 inch. Bars are missing or entire barrier missing. Bars are loose and rust is causing 50% deterioration to any part of barrier. Bars in place according to design. Repair or replace barrier to design standards. 9/1/98 A 1998 Surface Water Design Manual APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 10 - CONVEYANCE SYSTEMS (PIPES & DITCHES) Maintenance Component Pipes Open Ditches Catch Basins Defect Conditions When Maintenance is Needed Debris Barriers (e.g., Trash Rack) Sediment & Debris Vegetation Damaged Trash & Debris Sediment Vegetation Erosion Damage to Slopes Rock Lining Out of Place or Missing (If Applicable). Accumulated sediment that exceeds 20% of the diameter of the pipe. Vegetation that reduces free movement of water through pipes. Protective coating is damaged; rust is causing more than 50% deterioration to any part of pipe. Any dent that decreases the cross section area of pipe by more than 20 %. Trash and debris exceeds 1 cubic foot per 1,000 square feet of ditch and slopes. Accumulated sediment that exceeds 20 % of the design depth. Vegetation that reduces free movement of water through ditches: See "Ponds' Standard No. 1 Maintenance person can see native soil beneath the rock lining. See 'Catch Basins: Standard No. 5 See "Debris Barriers' Standard No.6 NO. 11- GROUNDS (LANDSCAPING) Results Expected When Maintenance is Performed Pipe cleaned of all sediment and debris. All vegetation removed so water flows freely through pipes. Pipe repaired or replaced. Pipe repaired or replaced. Trash and debris cleared from ditches. Ditch cleaned/ flushed of all sediment and debris so that it matches design. Water flows freely through ditches. See "Ponds' Standard No. 1 Replace rocks to design standards. See "Catch Basins' Standard No. 5 See "Debris Barriers" Standard No. 6 Maintenance Component Defect Conditions When Maintenance is Needed Results Expected When Maintenance Is Performed General Trees and Shrubs Weeds (Nonpoisonous) Safety Hazard Trash or Litter Damaged Weeds growing in more than 20% of the Landscaped area (trees and shrubs only). Any presence of poison ivy or other poisonous vegetation. Paper, cans, bottles, totaling more than 1. cubic foot within a landscaped area (trees and shrubs only) of 1,000 square feet. Limbs or parts of trees or shrubs that are split or broken which •affect more than 25% of the total foliage of the tree or shrub. Trees or shrubs that have been blown down or knocked over. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Weeds present In Tess than 5% of the landscaped area. No poisonous vegetation present in landscaped area. Area clear of litter. Trees and shrubs with Tess than 5% of total foliage with split or broken limbs. Tree or shrub in place free of injury. Tree or shrub in place and adequately supported; remove any dead or diseased trees. 1998 Surface Water Design Manual A _O 9/1/98 APPENDIX A MAINTENANCE STANDARDS FOR PRIVATELY MAINTAINED DRAINAGE FACILITIES NO. 13 - WATER QUALITY FACIUTIES (CONTINUED) D.) WetvauIts Maintenance Defect Component Condition When Maintenance Is Needed Results Expected When Maintenance is Performed Wetvautt Trash/ Debris Accumulation Sediment Accumulation In Vault Damaged Pipes Access Cover Damaged/ Not Working Vault Structure Damaged Baffles Access Ladder Damage Trash and debris accumulated in vault, pipe or inlet/ outlet, (Includes floatabies and non- fioatables). Sediment accumulation In vault bottom that exceeds the depth of the sediment zone plus 6- inches. Inlet/ outlet piping damaged or broken and in need of repair. Cover cannot be opened or removed, especially by one person. Vault: Cracks wider than 1/2 -inch and any evidence of soil particles entering the structure through the cracks, or maintenance/ Inspection personnel determines• that the vault is not structurally sound. Baffles corroding, cracking, warping and/ or showing signs of failure as determined by maintenance/ inspection. staff. Ladder is corroded or deteriorated, not functioning properly, missing rungs, has cracks and/ or misaligned. Trash and debris removed from vault. Removal of sediment from vault. Pipe repaired and/ or replaced. Pipe repaired or replaced to proper working specifications. No cracks wider, than 1/4 -Inch at the joint of the Inlet/ outlet pipe. Vault.is determined to be structurally sound. Repair or replace baffles to specifications. Ladder replaced or repaired to specifications, and is safe to use as determined by inspection personnel. 1998 Surface Water Design Manual A_11 9/1/98 July 7, 2006 Cizy of Tukwila Steven M. Mullet, Mayor Department of Community Development Steve Lancaster, Director Mr. George K. Hirai 15615 NE 62 "d CT. Redmond, WA 98052 RE: Notice of Incomplete Application SEPA E06 -013 Dear Mr. Hirai: The City of Tukwila's Planning Department received your SEPA application on July 3, 2006. On July 7, 2006 it was deemed to be incomplete because certain requirements of the application were not provided: Please provide the following: 1. A portion of the SEPA checklist was not filled out. The blank sheet is attached. Please return to the City in order for the application to be considered complete. Please note that the Department shall cancel an incomplete application if the applicant fails to submit the requested information within 90 -days following notification from the Department that the application is incomplete. The Department may extend up to 120 days if the applicant submits a written request for an extension prior to cancellation. The request must clearly demonstrate that the delay is due to circumstances beyond the applicant's control (such as the need for seasonal wetland data) or unusual circumstance not typically faced by other applicants, and that a good faith effort has been made to provide the requested materials (TMC 18.104.070). Once the above - mentioned information is provided, City staff can begin to review the application. If you have any questions, please feel free to call me at (206) 431 -3684 or you can email me at bmiles ci.tukwila.wa.us. Sjrely, Brandoh J. Miles Assistant Planner cc. File (E06 -01 6300 Southcenter Boulevard, Suite #100 • Tukwila, Washington 98188 • Phone: 206 - 431 -3670 • Fax: 206 - 431 -3665 • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments Proposed measures to avoid or reduce shoreline and land use impacts are: 6. How would the proposal be likely to increase demands on transportation or public service and utilities? Proposed measures to reduce or respond to such demand(s) are: 7. Identify, if possible, whether the proposal may conflict with Local, State, or Federal laws or requirements for the protection of the environment. Please respond to al1'4aestions. Use separate sheets as necessary. Applicant Responses: 3. How would the proposal be likely to deplete energy or natural resources? Proposed measures to protect or conserve energy and natural resources are: 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated (or eligible or under study) for governmental protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitats, historic..or cultural sites, wetlands, floodplains, or prime farmlands? Proposed measures to protect such resources or to avoid or reduce impacts are: 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? Agency Comments Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington INTRODUCTION This report presents the results of our geotechnical engineering investigation and evaluation of the Hirai Short Plat project in Tukwila, Washington. The site is located at the northwest corner of the intersection of South 132nd Street and Pacific Hwy South, as shown on the Vicinity Map in Figure 1. The purpose of this study is to explore and characterize the site's surface and subsurface conditions, and to provide geotechnical recommendations for site development. For our use in preparing this report, we were provided with an undated site plan titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc., showing the existing site topography and the planned lot layout. Project plans include developing this 0.58 -acre site into five single - family residential lots with associated pavement and utilities. Daylight basement retaining walls may be incorporated into some of the structures constructed on mildly sloping ground. Stormwater management plans will likely consist of on site detention, via either a vault or pipes. The proposed lot alignments and existing topography are shown on the Site Plan in Figure 2. SCOPE The purpose of this study is to explore and characterize the site subsurface conditions, and provide general recommendations for site development. Specifically, our scope of services includes the following: 1. Review available soils and geologic maps of the area. 2. Explore the subsurface soil and groundwater conditions within the site with trackhoe- excavated test pits. Trackhoe was subcontracted by NGA. 3. Map the surficial slope conditions and produce cross - sections. 4. Perform grain -size sieve analysis on soil samples. 5. Provide our opinion regarding slope stability. RECEIVED CITY OFTUKWILA 6. Provide recommendations for earthwork, foundation support, and slabs- on- grade, J UN 1 2 2006 7. Provide recommendations for subgrade preparation and pavements. 8. Provide recommendations for site drainage and erosion control. PERNIITCENTER 9. Document the results of our findings, conclusions, and recommendations in a written geotechnical report. Pao NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 2 SITE CONDITIONS Surface Conditions The property is an irregularly shaped parcel covering approximately 0.58 acres. The property is bordered to the north and west by developed residential property, to the east by Pacific Hwy South, and to the south by South 132nd Street. The site slopes gently down toward the eastern property line, where the slope then becomes moderate to steep over a vertical relief of less than 10 feet, buttressed by a 3.5 -to 8.0 -foot high rockery retaining wall. Profiles of the existing ground surface and the interpretive subsurface conditions are shown on Cross Sections A -A', B -B', and C -C', in Figures 3 through 5, respectively. Access to the property is currently from a gravel driveway off South 132nd Street along the southwest corner of the site. The site is currently undeveloped, covered with grass, blackberries, and a few conifer and fruit trees., 1The northeast corner of the site in particular is heavily vegetated. We observed ponding water within the site during- our site visit on March 15, 2006. This water appeared to be collecting on the surface of a previously graded building pad, where a structure was likely located in the past. The approximate location of the ponding water is shown on the Site Plan, Figure 2. Subsurface Conditions Geology: The. geologic units for this area are shown on the Preliminary Geologic Map of Seattle and Vicinity, Washington, by Howard H. Waldron, Bruce A. Liesch, Donald R. Mullineaux, and Dwight R. Crandell (U.S.G.S., 1962). The site is mapped as Vashon, till (Qt), and the area just east of the site is mapped as undifferentiated deposits of the Pleistocene age (Qu). The till is described as a nonsorted mixture of clay, silt, sand, pebbles, cobbles, and boulders. Our explorations generally encountered glacially consolidated silt with trace fine sand. We interpreted this material to be an interglacial deposit, likely consolidated during the Vashon age glaciation. Explorations: The subsurface conditions within the site were explored on March 15, 2006 by excavating eight test pits to depths ranging from 2.0 to 11.0 feet below the existing ground surface using a trackhoe. The approximate locations of our explorations are shown on the Site Plan in Figure 2. An engineer from NGA was present during the explorations, examined the soils and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the test pits. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 _ Page 3 The soils were visually. classified in general accordance with the Unified Soil Classification System, — presented in Figure 6. The logs of our test pits are attached to this report and are presented as Figures 7 and 8. We present a brief summary of the subsurface conditions in the following paragraph. For a detailed description of the subsurface conditions, the logs of the test pits should be reviewed. Test Pits 2, 4, and 8 exposed a 1.3 -to 2.0 -foot thick layer of dark brown to black silt with trace fine sand and roots, which was interpreted as topsoil/modified ground. Test pits 1, 3, and 5 through 7 exposed a 1.0 -to 2.8 -foot thick surficial layer of dark brown silt with trace fine sand, roots, bricks, and other miscellaneous rubble. We interpreted this material to be undocumented fill. Underlying the topsoil and fill, our explorations exposed stiff to very stiff, brown -gray to blue -gray silt with trace fine sand extending to the bottom of the explorations. We interpreted this material to be native glacially consolidated material. Hydrologic Conditions Groundwater seepage was not encountered in any of our explorations, however, we would expect that a perched groundwater condition may develop on this site during the wet season. Perched water occurs when surface water infiltrates through less dense, more permeable soils, such as topsoil and fill, and accumulates on top of a relatively impermeable material, such as the very stiff to stiff native silt soils. Perched water does not represent a regional groundwater "table" within the upper soil horizons. Perched water tends to vary spatially and is dependent upon the amount of rainfall. We would expect the amount of groundwater to decrease during drier times of the year and increase during wetter periods. LABORATORY ANALYSIS We performed two grain -size analyses on selected soil samples obtained from the explorations, located in the central section of the development area, as shown on the Site Plan in Figure 2. The results of the sieve analyses are presented as Figures 9 and 10. The analyses indicated that the soils underlying the site are predominately composed of silt. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 4 SENSITIVE AREA EVALUATION Seismic Hazard We reviewed the 2003 International Building Code (IBC) for seismic site classification for this.project. Since very stiff to stiff silt was encountered underlying the site at depth, the site conditions best fit the IBC description for Site Class D. Hazards associated with seismic activity include liquefaction potential and amplification of ground motion. Liquefaction is caused by a rise in pore pressures in a loose, fine sand deposit beneath the groundwater table. It is our opinion that the competent glacially consolidated deposits interpreted to underlie the site have a low potential for liquefaction or amplification of ground motion. Erosion Hazard The criteria used for determination of the erosion hazard for affected areas include soil type, slope gradient, vegetation cover, and groundwater conditions. The erosion sensitivity is related to vegetative cover and the specific surface soil types, which are related to the underlying geologic soil units. The Soil Survey of King County Area, Washington, by the Soil Conservation Service (SCS) was reviewed to determine the erosion hazard of the on -site soils. The site was mapped just beyond the boundaries of the Soil Survey; however, the surface soils are closely associated with the mapping unit of Kitsap Silt loam, 8 to 15 percent slopes.. The erosion hazard for this material is listed as moderate to severe. It is our opinion that the erosion hazard for site soils should be low in areas where vegetation is maintained, and severe in areas of exposed silt. Landslide Hazard/Slope Stability The criteria used for evaluation of landslide hazards include soil type, slope gradient, and groundwater conditions. The overall site inclinations are gentle to moderate, however, a slope below the five residential lots has inclinations of up to 30 degrees, with a vertical relief of less than 10 feet. This slope is buttressed by a 3.540 8.0 -foot high rockery retaining wall. The core of the site slope is inferred to consist of stiff to very stiff glacially consolidated silt. Relatively shallow failures as well as surficial erosion are natural processes and could be expected on the slope below the site during severe rainstorms. However, these processes would be limited through the NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 5 maintenance of a vegetative cover and proper stp{mwater management. It is our opinion that there is not a significant potential for deep- seated slope f'ailure under current site conditions. Proper site grading and drainage as well as vegetation management as recommended in this report should help maintain current stability conditions. Also, the recommended effective structure setback should reduce the potential adverse impacts of site development on the slope and vice versa. CONCLUSIONS AND RECOMMENDATIONS General It is our opinion from a geotechnical standpoint that the, site is compatible with the planned development. Our explorations indicated that the planned development area is generally underlain by a one -to three -foot thick surficial layer of very soft topsoil and fill, underlain by competent silt deposits. The medium stiff or better native soils should provide adequate support for the planned structures and roadways. We recommend that the structures be designed utilizing shallow foundations. Footings should extend through any undocumented fill, or loose materials, and be founded on the underlying medium stiff or better native soils or structural fill extending to these soils. Our explorations generally encountered medium stiff or better native soils at depths of two feet below the existing ground surface. Adequate structure setbacks should be maintained in relationship to the locally steep sloping ground and rockery retaining wall. To_protect the . existing slope and rockery from development, we recommend that the downhill structure footing lines be set back at least 10 feet from a line drawn at 27 degrees from the horizontal, -starting at the base of the rockery and extending upwards into the slope, intersecting the site ground surface above. NGA should be retained to evaluate final structure placement on each lot. Under no circumstances should water be allowed to flow over or concentrate on the steep slope, both during construction and after construction has been completed. The yard areas should be graded to direct runoff away from the top of steep slope, if possible. We recommend that stormwater runoff from the roofs, driveway, footing drains, and yard drains be collected in catch basins and tightlined into an approved stormwater management system. We understand that an underground detention vault or pipe will likely be considered for stormwater management on this project. If the vault will be located in an unexplored area of the site, or will extend to NELSON GEOTECHNICAL ASSOCIATES, INC. Gebtechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 6 a depth below the depths explored, we should observe additional explorations in the area of the planned vault to confirm that the subsurface conditions are consistent with our design recommendations. Grading for the vault should be in accordance with the recommendations found in the Site Preparation and Grading and Temporary and Permanent Slopes subsections of this report. We would expect wet surficial soil conditions during the wetter times of the year We recommend the use of footing drains around structures, and wall drains behind stem/retaining walls. Specific drainage recommendations are given in the Site Drainage subsection of this report. The site soils are considered extremely moisture- sensitive and will disturb easily even in moderately wet conditions. We strongly recommend that construction take place during the drier summer months and suspended during wet periods. If construction is to be attempted in wet conditions, major additional expenses and delays should be expected due to the wet conditions. Additional expenses could include the need for placing a blanket of rock spalls and/or geo -fabric on exposed subgrades, construction traffic areas, and paved areas prior to placing structural fill, and the need for using all- weather material for structural fill. The use of the native on -site soils as structural fill will likely be unfeasible, but will depend on the moisture content of the soil at the time of construction. NGA should be retained to determine if the on -site soils could be used as structural fill material prior to construction. We should also note that major erosion control expenses and delays may be incurred if the site is to be developed in wet weather. Erosion Control The erosion hazard for the on -site soils is considered severe for exposed soils but actual erosion potential will be dependent on how the site is graded and how water is allowed to concentrate. Best Management Practices (BMPs) should be used to control erosion. Areas disturbed during construction should be protected from erosion. Erosion control measures may include covering exposed soils with a layer of crushed rock, diverting surface water away from the stripped or disturbed areas, and limiting construction traffic on prepared subgrades. Silt fences or straw bales should be erected to prevent muddy water from leaving the site. Disturbed areas should be planted as soon as practical and the vegetation should be maintained until it is established. Other erosion control measures may include the use of a temporary sediment control pond or Baker's tanks to store muddy water prior to leaving the site. This can be NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat — Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 7 evaluated at the time of construction based on the actual site conditions. The erosion potential of areas not stripped of vegetation should be low. Temporary and Permanent Slopes Temporary cut slope stability is a function of many factors, including the type and consistency of soils, depth of the cut, surcharge loads adjacent to the excavation, length of time a cut remains open and the presence of surface or groundwater. It is exceedingly difficult under these variable conditions to estimate a stable, temporary, cut slope angle. Therefore, it should be the responsibility of the contractor to maintain safe slope configurations since he is continuously at the job site, able to observe the nature and condition of the cut slopes, and able to monitor the subsurface materials and groundwater conditions encountered. - The following information is provided solely for the benefit of the owner and other design consultants and should not be construed to imply that Nelson Geotechnical Associates, Inc. assumes responsibility for job site safety. Job site safety is the sole responsibility of the project contractor. For planning purposes, we recommend that temporary cuts in any undocumented fill and loose soils be no steeper than 2.0 Horizontal to 1.0 Vertical (2H:1 V). Cuts in the native silt could stand at inclinations as steep as 1H: 1V. If significant groundwater seepage is encountered, we would expect that flatter inclinations would be necessary. We recommend that cut slopes be protected from erosion. These erosion protection measures may include covering cut slopes with plastic sheeting and diverting surface runoff away from the top of cut slopes. We do not recommend vertical slopes for cuts deeper than four feet, if worker access is necessary. We recommend that cut slope heights and inclinations conform to appropriate OSHA/WISHA regulations. We recommend that permanent cuts in the ' native silt, as well as any permanent fill slopes to be constructed on site be no steeper than 2.0 unit Horizontal to 1.0 unit Vertical (2.0H:1V). We recommend that permanent cut and fill slopes be protected from erosion. Vegetation should be planted on permanent slopes and maintained until established. To reduce the potential for erosion, surface water runoff should not be allowed to flow uncontrolled over the permanent slopes. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 8 Site Preparation and Grading After erosion control measures are implemented, site preparation should consist of stripping the development areas of organics, any fill, and loose soils to expose medium stiff or better native soils for the structural fill subgrade, and in foundation, slab, and pavement areas. Our explorations generally encountered medium stiff or better native soils at depths of two feet below the existing ground surface. However, additional stripping may be required in unexplored areas of the site or if the exposed subgrade becomes disturbed due to wet weather. The stripped materials should be removed from the site or stockpiled for later use as landscaping fill. If the stripped material is to be stockpiled on site, the stockpiles should be kept away from the steeper portions of the slope and covered with plastic at all times. We recommend that any undocumented fill encountered in the structure and pavement areas be removed and replaced with structural fill or rock spalls extending to competent native material. Depending on subgrade and weather conditions, pavement and slab subgrade should be compacted to a'. non - yielding condition using static rollers then proof - rolled with a heavy rubber -tired piece of equipment. Areas observed to pump or weave during the proof -roll test should be reworked to structural fill specifications or over - excavated and replaced with properly compacted structural fill or rock spalls. For better pavement and slab -on -grade performance, especially in wet conditions, a one -foot thick layer of crushed rock may be placed over the prepared subgrade prior to placing asphalt or concrete. Final subgrade preparation recommendations can be provided at the time of construction. If significant surface water flow is encountered during construction, this flow should be diverted around areas to be developed and the exposed subgrade maintained in a semi -dry condition. If wet conditions are encountered, alternative site stripping and grading techniques will be necessary due to the highly sensitive nature of the site soils. These methods could include using large excavators equipped with wide tracks and a smooth bucket to complete site grading and covering exposed subgrade with a layer of crushed rock for protection. If wet conditions are encountered or construction is attempted in wet weather, the subgrade should not be compacted as this could cause further subgrade disturbance. In wet conditions it may be necessary to cover the exposed subgrade with a layer of crushed rock as soon as it is exposed to protect the moisture sensitive soils from disturbance by machine or foot traffic during construction. The prepared subgrade should be protected from construction traffic and surface water should be diverted around prepared subgrade. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat - Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 9 The site soils are considered extremely moisture- sensitive and will disturb easily even in moderately wet conditions. We strongly recommend that construction take place during the drier summer months. If construction takes place during the wet season, additional expenses and delays should be expected due to the wet conditions. This may include the need for installing an interceptor drain along the uphill side of the site. Additional expenses could also include the need for placing a blanket of rock spalls and/or geo- fabric on exposed• subgrades, construction traffic areas, and paved areas prior to placing structural fill. The use of on -site soils as structural fill will likely be unfeasible, but will be highly dependent on the moisture content of the soil at the time of construction. NGA should be retained to determine if the on- site soils could be used as structural fill material at the time of construction. For planning purposes, the use of the on -site material as structural fill should be considered unfeasible. Foundations Conventional shallow spread foundations should be placed on undisturbed medium stiff or better native soils or be supported on structural fill extending to those soils. Where undocumented fill or less dense soils are encountered at the planned footing elevation, the subgrade should be over - excavated to expose suitable bearing soil. The over - excavation may be filled with structural fill, or the footing may be extended down to the native bearing soils. If footings are supported on structural fill, the fill zone should extend outside the edges of the footing a distance equal to one -half of the depth of the over - excavation below the bottom of the footing. Footings, including interior footings, should extend at least 18 inches below the lowest adjacent finished ground surface for frost protection and bearing capacity considerations. Foundations should be designed in accordance with the 2003 IBC. Footing widths should be based on the anticipated loads and allowable soil bearing pressure. Standing water should not be allowed to accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavation prior to placing concrete. It might be prudent to place a layer of crushed rock on prepared foundation subgrade to limit subgrade disturbance by foot traffic. For foundations constructed as outlined above, we recommend an allowable design bearing pressure of not more than 2,000 pounds per square foot (psf) be used for the design of foundations supported on the medium stiff or better native soils or structural fill extending to the competent native soils. A representative of NGA should evaluate the foundation bearing soil. We should be consulted if higher NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 10 bearing pressures are needed. Current IBC guidelines should be used when considering increased allowable bearing pressure for short-term transitory wind or seismic loads. Potential foundation settlement using the recommended allowable bearing pressure is estimated to be less than one -inch total and 1/2-inch differential between adjacent footings or across a distance of about 20 feet based on our experience with similar projects. Lateral loads may be resisted by friction on the base of the footing and passive resistance against the subsurface portions of the foundation. A coefficient of friction of 0.30 may be used to calculate the base friction and should be applied to the vertical dead load only. Passive resistance may be calculated as a triangular equivalent fluid pressure distribution. An equivalent fluid density of 200 pounds per cubic foot (pcf) should be used for passive resistance design for a level ground surface adjacent to the footing. This level surface should extend a distance equal to at least three times the footing depth. These recommended values incorporate safety factors of 1.5 and 2.0 applied to the estimated ultimate values for frictional and passive resistance, respectively. To achieve this value of passive resistance, the foundations should be poured "neat" against the native medium dense /stiff soils or compacted fill should be used as backfill against the front of the footing. We recommend that the upper one -foot of soil be neglected when calculating the passive resistance. Structural Fill General: Fill placed beneath foundations, pavement, or other settlement - sensitive structures should be placed as structural fill. Structural fill, by definition, is placed in accordance with prescribed methods and standards, and is monitored by an experienced geotechnical professional or soils technician. Field monitoring procedures would include the performance of a representative number of in -place density tests to document the attainment of the desired degree of relative compaction. The area to receive the fill should be suitably prepared as described in the Site Preparation and Grading subsection prior to beginning fill placement. Materials:. Structural fill should consist of a good quality, granular soil, free of organics and other deleterious material and be well graded to a maximum size of about three inches. All - weather fill should contain no more than five - percent fines (soil finer than U.S. No. 200 sieve, based on that fraction passing the U.S. 3/4 -inch sieve). The use of on- site soils as structural fill will likely be unfeasible, but will be NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 11 highly dependent on the moisture content of the material at the time of construction. Most of the on -site soils will be virtually impossible to compact to structural fill specifications in wet conditions. We should be retained to evaluate proposed structural fill materials prior to construction. Fill Placement: Following subgrade preparation, placement of structural fill may proceed. All filling should be accomplished in uniform lifts up to eight inches thick. Each lift should be spread evenly and be thoroughly compacted prior to placement of subsequent lifts. All structural fill underlying building areas and pavement subgrade should be compacted to a minimum of 95 percent of its maximum dry density. Maximum dry density, in this report, refers to that density as determined by the ASTM D -1557 Compaction Test procedure. The moisture content of the soils to be compacted should be within about two percent of optimum so that a readily compactable condition exists. It may be necessary to over - excavate and remove wet soils in cases where drying to a compactable condition is not feasible. All compaction should be accomplished by equipment of a type and size sufficient to attain the desired degree of compaction. Slab -on -Grade Slabs -on- grade, if used, should be supported on subgrade soils prepared as described in the Site Preparation and Grading subsection of this report. We recommend that all floor slabs be underlain by at least six inches of free - draining sand or gravel for use as a capillary break. We recommend that the capillary break be hydraulically connected to the footing drain system to allow free drainage from under the slab. A suitable vapor barrier, such as heavy plastic sheeting (6 -mil minimum), should be placed over the capillary break material. Pavements Pavement subgrade preparation, and structural filling where required, should be completed as recommended in the Site Preparation and Grading and Structural Fill subsections of this report. Any undocumented fill should be removed and replaced with structural fill or thoroughly compacted prior to placing the pavement section. The pavement subgrade should be proof - rolled with a heavy, rubber -tired piece of equipment, to identify soft or yielding areas that require repair. The ability to leave some of the undocumented fill in the payment subgrade will be dependent on the nature of the fill and expected NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 12 pavement performance. We should be retained to evaluate any fill to be left in pavement areas, observe the proof - rolling, and recommend repairs prior to placement of the asphalt or hard surfaces. Stormwater Management The soils exposed in our explorations on this site consisted of silt with trace fine sand. These soils have extremely low permeability and are not considered suitable for stormwater infiltration. A detention vault or pipe may provide a more practical alternative for stormwater management on this site. The possible location of a detention vault for this project had not been established' at the time that this report was prepared. Preliminary recommendations for excavation and retaining walls of an underground vault are included in the following subsections of this report. However, if the vault will be located in an unexplored area of the site, or will extend to a depth below the depths explored, we should observe additional explorations in the area of the planned vault to confirm that the subsurface conditions are consistent with our design recommendations. We understand that stormwater may also be handled using a detention pipe, rather than a detention vault. If a detention pipe is used, the bottom of the trench should be cleared of any loose or sloughing material prior to placing the pipe. The pipe should be underlain by one to two feet of washed rock and surrounded with washed rock at least halfway up the pipe, placed evenly in small lifts on both sides of the pipe. The top of the washed rock fill should be covered with filter fabric (Mirafi 140 N or equivalent) prior to placing native material. We recommend that construction equipment not be operated over the pipe until at least three feet of fill is placed over the pipe, or as recommended by the manufacturer. If native material is used over the washed rock, it should be clear of particles over 3 inches in diameter and be placed in thin lifts (no more than 6 inches in thickness). The fill should be compacted using walk behind vibratory plate compactors. We should be retained to review the layout and design of any detention pipe systems. Retaining Walls Retaining walls may be incorporated into project plans in the form of daylight basement stem -walls for the new structures and for any detention vault. The lateral pressure acting on subsurface retaining walls is dependent on the nature and density of the soil behind the wall, the amount of lateral wall movement which can occur as backfill is placed, wall drainage conditions, the inclination of the backfill, and other NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 13 possible surcharge loads. For walls that are free to yield at the top at least one thousandth of the height of the wall (active condition), soil pressures will be less than if movement is limited by such factors as wall stiffness or bracing (at -rest condition). We recommend that walls supporting horizontal backfill and not subjected to hydrostatic forces be designed using a triangular earth pressure distribution equivalent to that exerted by a fluid with a density of 45 pcf for yielding (active condition) walls, and 65 pcf for non- _, yielding (at -rest condition) walls. These recommended lateral earth pressures are for a drained granular backfill and are based on the assumption of a horizontal ground surface behind the wall for a distance of at least the subsurface height of the wall, and do not account for surcharge loads. Additional lateral earth pressures should be considered for surcharge loads acting adjacent to subsurface walls and within a distance equal to the subsurface height of the wall. This would include the effects of surcharges such as traffic loads, floor slab and foundation loads, slopes, or other surface loads. Also, hydrostatic and buoyant forces should be included if the walls could not be drained. We could consult with you and your structural engineer regarding additional loads on retaining walls during final design, if needed. The lateral pressures on walls may be resisted by friction between the foundation and subgrade soil, and by passive resistance acting on the below -grade portion of the foundation. Recommendations for frictional and passive resistance to lateral loads are presented in the Foundations subsection of this report. All wall backfill should be well compacted as outlined in the Structural Fill subsection of this report. Care should be taken to prevent the buildup of excess lateral soil pressures, due to over - compaction of the wall backfill. This can be accomplished by placing wall backfill in thin loose lifts and compacting it with small, hand- operated compactors within a distance behind the wall equal to at least one -half the height of the wall. The thickness of the loose lifts should be reduced to accommodate the lower compactive energy of the hand - operated equipment. The recommended level of compaction should still be maintained. Permanent drainage systems should be installed for retaining walls. Recommendations for these systems are found in the Subsurface Drainage subsection of this report. We recommend that we be retained to evaluate the proposed wall drain backfill material and drainage systems. NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 14 Site Drainage Surface Drainage: Final site grades should allow for drainage away from the planned structures. We suggest that the finished ground be sloped at a minimum gradient of three percent for a distance of at least 10 feet away from the buildings. Surface water should be collected by permanent catch basins and drain lines, and be discharged into an appropriate discharge system. Water should not be allowed to collect in any area where footings, slabs, or pavements are to be constructed. Surface water generated from paved areas and roof drains should be routed into permanent catch basins and then tightlined into appropriate stormwater facilities. Water should not be allowed to flow over the slopes or adjacent rockery. Subsurface Drainage: If groundwater is encountered during construction, we recommend that the contractor slope the bottom of the excavations and collect the water into ditches and small sump pits where the water can be pumped out and routed to a suitable discharge point. We recommend the use of footing drains around the planned structures and wall drains behind retaining walls. Footing drains should be installed at least one foot below planned finished floor elevation. The drains should consist of a minimum four-inch-diameter, rigid, slotted or perforated, PVC pipe surrounded by free - draining material, such as washed rock, wrapped in a filter fabric. We recommend that an 18- inch -wide zone of clean (less than three - percent fines), granular material be placed along the back of the walls above the drain. Pea gravel is an acceptable drain material or a drainage composite may be used instead. The free - draining material should extend up the wall to one foot below the finished surface. The top foot of backfill should consist of impermeable soil placed over plastic sheeting or building paper to minimize surface water or fines migration into the footing drain. Footing drains should discharge into tightlines leading to an appropriate collection and discharge' point with convenient cleanouts to prolong the useful life of the drains. Roof drains should not be connected to footing drains. If a detention vault or pipe is used and these elements can not be effectively drained, they should be designed to withstand hydrostatic forces. USE OF THIS REPORT NGA has prepared this report for Mr. George Hirai, and his agents, for use in the planning and design of the development planned on this site only. The scope of our work does not include services related to construction safety precautions and our recommendations are not intended to direct the contractors' NELSON GEOTECHNICAL ASSOCIATES, INC. Geotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 15 methods, techniques, sequences, or procedures, except as specifically described in our report for consideration in design. There are possible variations in subsurface conditions between the explorations and also with time. Our report, conclusions, and interpretations should not be construed as a warranty of subsurface conditions. A contingency for unanticipated conditions should be included in the budget and schedule. We recommend that NGA be retained to provide monitoring and .consultation services during construction to confirm that the conditions encountered are consistent with those indicated by the explorations, to provide recommendations for design changes should the conditions revealed during the work differ from those anticipated, and to evaluate whether or not earthwork and foundation installation activities comply with contract plans and specifications. We should be contacted a minimum of one week prior to construction activities and could attend pre - construction meetings if requested. Within the limitations of scope, schedule, and budget, our services have been performed in accordance with generally accepted geotechnical engineering practices in effect in this area at the time this report was prepared. No other warranty, expressed or implied, is made. Our observations, findings, and opinions are a means to identify and reduce the inherent risks to the owner. o -O -o NELSON GEOTECHNICAL ASSOCIATES, INC. Gdotechnical Engineering Evaluation Hirai Short Plat Tukwila, Washington March 30, 2006 NGA File No. 733906 Page 16 It has been a pleasure to provide service to you on this project. If you have any questions or require further information, please call. Sincerely, NELSON GEOTECHNICAL ASSOCIATES, INC. vin A. McCaughan, EIT Senior Staff Engineer Khaled M. Shawish, PE Principal CAM: KMS:lam Ten Figures Attached NELSON GEOTECHNICAL ASSOCIATES, INC. ,‘ 004itioilciieighlk -.".•1------.•-•.--.--- -..---2N .01 01 coiS 1 ,•0., No . fo 6 ,o 1 _ gi iti. 1., ,./ • 'N' C‘I'l 0 s. 2ethst : ... 1,-- • i S 128t1icSt L._ ! I 4 139113P( s.ftot'or .:1.3211ii. ,i: ti : i S".141.' (-7-.-,S133ictt 1-- ,1341/IS : S 136th St1 VICINITY MAP Not to Scale o ; I Z- S 120th Pi 411 'I ,.-• ''I:'....i. .i - ::..-,.. . . 4'.1.1A_ 1.(7.i., '0- .: ' ...: '. t'6'''7- ' ''l...f,. z .•.-j•"-. l ; .'A1: ' te: i .--4 W. .....': t • ..._:_0.... . «1 44 `5 -1:s 11_ . _- 2• 5_' . . _. 76-,c(...,..i4-*. • .: .....s...L. ... 17t' . .7 0E- ..- ,.. .., I I tcet 5r (.4 .1271IrSt. • 113401-41-?.' • • .• . ..„ IV' 138th SiF,_Isc7;J 9th St o.20436*IeciOueet.'inc. Project Number 733906 Figure 1 140th 14— I Tukwila, WA Hirai Short Plat Vicinity Map NELSON GEOTECHNICAL NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS 17311-155th M. NE, 0.400 Woodinville. WA 911072 (426) 488-104301 F88481-2510 WanStaleeiChetell ref143766 WWW/101,011000 2 No. Date Revision By g CK 1 1 3/20/06 Original ACO CAM F3 Concrete Walkway OOP TP-3 •, 00'. .00 � TP -3 —■ Existing Rockery Property Line TP -1 Number and Approximate —.- I Location of Test Pit A A' Approximate Location of Cross- Section Catch basin Ditch 0 40 80 Reference: Site Plan is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. Project Number 733906 Scale: 1 inch = 40 feet Figure 2 Hirai Short Plat Site Plan NELSON GEOTECHNICAL NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS woodnrlN, WA Dd072 17311 -1367 A... NH wao6 (426) 4abtaai / Fax 491.010 itiinne wwwnala6n0ao .mm No. Date Revision By 3/20/06 Original ACA cra c 0 w0 ci cr, Z o c o 3 a CD 1 a ar (no oz a am o mPi n z= pfl RE GEOTECHNICAL ENGINEERS & GEOLOGISTS a r z a 0 m 0 2 0 Southwest 230— Approximate Elevation (feet) 210 190 Gravel Alleyway Fill TP -7 (Projected 15 -ft. Southeast) 170— 18° Stiff to very stiff silt with trace sand Fill TP -1 Concrete Walkway Existing Rockery up to 30° locally -� R Northeast — 230 0 Exploration 210 190 — 170 20 40 60 80 100 120 140 160 Distance (feet) Test Pit Designation —> TP -1 Groundwater Level —> y During Exploration Geologic Contact --> ? (approximate) --9 NOTES: 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 2) Elevations are approximate. Reference: Cross Section is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. • NGA Drafting 20061733906 H raYCS.dwg I i I i I I 1 1 I1 co c ro W n cc Z o c rn 3 co 0 s s 0 to A Southwest 220 -- Approximate Elevation (feet) 200 180 160 B Gravel Alleyway R TP-5 B' Topsoil & Fill Existing Rockery Stiff to very stiff silt TP-4 Concrete with trace sand Walkway 20 40 60 80 Distance (feet) Exploration Test At Designation --) TP -1 Groundwater Level — y During Exploration Geologic Contact —j ? (approximate) 100 120 140 Northeast — 220 200 180 -- 160 NOTES: 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 2) Elevations are approximate. Reference: Cross Section is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. NGADrafting 20061733906 Hfral/CS.drrg • c rD cn JegwnN toe(oad z 0 0 C3 m 0 w 0 Southwest 220 Approximate Elevation (feet) 200 180 160 0 7 Gravel Alleyway R Stiff to very stiff silt with trace sand Existing Rockery Concrete Walkway Exploration Test Pit Designaation -- TP -1 Groundwater Level During Exploration Geologic Contact -- 3 ? (approximate) -- —? 20 40 60 Distance (feet) 80 100 120 Northeast -- 220 200 180 — 160 NOTES: 1) Stratigraphic conditions are interpolated between the explorations. Actual conditions may vary. 2) Elevations are approximate. Reference: Cross Section is based on a topographic site plan dated June 1, 2005, titled "Hirai Site Plan," prepared by Medina Consulting Engineers, Inc. NGADraRing 2006V33SQ6 hftraVCS.cfwg • • • UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS GROUP SYMBOL GROUP NAME COARSE - GRAINED SOILS MORE THAN 50 % RETAINED ON NO. 200 SIEVE GRAVEL MORE THAN 50 % OF COARSE FRACTION RETAINED ON NO. 4 SIEVE CLEAN GRAVEL G.W WELL - GRADED, FINE TO COARSE GRAVEL GP POORLY- GRADED GRAVEL GRAVEL WITH FINES GM SILTY GRAVEL GC CLAYEY GRAVEL SAND MORE THAN 50 % OF COARSE FRACTION PASSES NO. 4 SIEVE CLEAN SAND SW WELL - GRADED SAND, FINE TO COARSE SAND SP POORLY GRADED SAND SAND WITH FINES SM SILTY SAND SC CLAYEY SAND FINE - GRAINED SOILS MORE THAN 50 % PASSES NO. 200 SIEVE SILT AND CLAY LIQUID LIMIT LESS THAN 50 % INORGANIC ML SILT CL CLAY ORGANIC OL ORGANIC SILT, ORGANIC CLAY SILT AND CLAY LIQUID LIMIT 50 % OR MORE INORGANIC MH SILT OF HIGH PLASTICITY, ELASTIC SILT CH CLAY OF HIGH PLASTICITY, FLAT CLAY ORGANIC OH ORGANIC CLAY, ORGANIC SILT NOTES: HIGHLY ORGANIC SOILS PT PEAT 1) Field classification Is based on visual examination of soil In general accordance with ASTM D 2488 -93. 2) Soil classification using laboratory tests Is based on ASTM D 2488 -93. 3) Descriptions of soil density or consistency are based on Interpretation of blowcount data, visual appearance of soils, and/or test data. Project Number 733906 SOIL MOISTURE MODIFIERS: Dry - Absence of moisture, dusty, dry to the touch Moist - Damp, but no visible water. Wet - Visible free water or saturated, usually soil Is obtained from below water table Figure 6 Hirai Short Plat Soil Classification Chart NELSON GEOTECHNICAL NGA ASSOCIATES, INC. GEOTECHNICAL ENGINEERS & GEOLOGISTS 11511. 16611. Aw. M. Al60 ..�,�.y. Woodhwt. WA a5072 Wm6lahsdCMlen( 09)7811;8! (425) 486 -1668 / Fax 481 -2810 NwwnN6orp6oN No. Date Revision By CK 3/20/06 Original ACO CAM 6 7 DEPTH (FEET) LOG OF EXPLORATION USC SOIL DESCRIPTION TEST PIT ONE 0.0 - 2.0 2.0 - 8.0 8.0 -10.0 ML DARK BROWN SILT WITH TRACE FINE SAND, DARK ORGANICS, BRICK, AND TIMBER (VERY SOFT, MOIST) (FILL) ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND (STIFF, MOIST) ML BLUE -GRAY SILT WITH TRACE FINE SAND (VERY STIFF, MOIST) SAMPLES WERE COLLECTED AT 1.8, 3.0, AND 9.0 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 2.0 FEET TEST PIT WAS COMPLETED AT 10.0 FEET ON 3/15/06 TEST PIT TWO 0.0 -1.3 DARK BROWN TO BLACK SILT WITH TRACE FINE SAND AND ROOTS (TOPSOIL) 1.3 -7.0 ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND (STIFF, MOIST) 7.0 -8.5 ML BLUE -GRAY SILT WITH TRACE FINE SAND (VERY STIFF, MOIST) SAMPLES WERE COLLECTED AT 0.8, 2.5, AND 8.0 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 1.3 FEET TEST PIT WAS COMPLETED AT 8.5 FEET ON 3/15/06 TEST PIT THREE 0.0 - 3.2 3.2 -10.5 10.5- 11.0 TEST PIT FOUR 0.0 - 1.3 . 1.3 - 2.0 TEST PIT FIVE 0.0 - 1.0 1.0 - 5.5 ACO:CAM ML DARK BROWN SILT WITH TRACE FINE SAND, ROOTS, BRICK, AND CONCRETE (VERY SOFT, MOIST TO WET) (FILL) ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND (STIFF, MOIST) ML BLUE -GRAY SILT WITH TRACE FINE SAND (VERY STIFF, MOIST) SAMPLES WERE COLLECTED AT 3.0, 4.0, AND 10.6 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 3.2 FEET TEST PIT WAS COMPLETED AT 11.0 FEET ON 3/15/06 DARK BROWN TO BLACK SILT WITH TRACE FINE SAND AND ROOTS (TOPSOIL) ML BROWN -GRAY SILT. WITH TRACE FINE SAND (STIFF, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED TEST PIT CAVING WAS NOT ENCOUNTERED TEST PIT WAS COMPLETED AT 2.0 FEET ON 3/15/06 ML DARK BROWN SILT WITH TRACE FINE SAND, TOPSOIL, AND GARBAGE (VERY SOFT, MOIST TO WET) (FILL) ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND (STIFF, MOIST) SAMPLE WAS COLLECTED AT 5.0 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 1.0 FEET TEST PIT WAS COMPLETED AT 5.5 FEET ON 3/15/06 NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 733906 FIGURE 7 LOG OF EXPLORATION • DEPTH (FEET) USC SOIL DESCRIPTION TEST PIT SIX - 0.0 -1.5 ML DARK BROWN SILT WITH TRACE FINE SAND, BRICKS, AND GARBAGE (VERY SOFT, MOIST) (FILL) 1.5 - 4.5 ML BROWN -GRAY SILT WITH TRACE FINE SAND (STIFF, MOIST) SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED HEAVY TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 1.5 FEET TEST PIT WAS COMPLETED AT 4.5 FEET ON 3/15/06 TEST PIT SEVEN 0.0 -2.8 ML BROWN -GRAY, IRON -OXIDE STAINED, SILT WITH TRACE FINE SAND AND ROOTS (VERY SOFT, MOIST) (FILL) 2.8 - 5.2 ML BROWN -GRAY SILT WITH TRACE FINE TO MEDIUM SAND AND FINE GRAVEL (STIFF, MOIST) SAMPLES WERE COLLECTED AT 1.5 AND 4.5 FEET GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED MODERATE TEST PIT CAVING WAS ENCOUNTERED BETWEEN 0.0 AND 2.8 FEET TEST PIT WAS COMPLETED AT 5.2 FEET ON 3/15/06 , TEST PIT EIGHT 0.0 - 2.0 DARK BROWN TO BLACK SILT WITH TRACE FINE SAND AND ROOTS (TOPSOIL) 2.0 -2.4 ML BROWN -GRAY SILT WITH TRACE FINE SAND (STIFF, MOIST) ACO:CAM SAMPLES WERE NOT COLLECTED GROUNDWATER SEEPAGE WAS NOT ENCOUNTERED TEST PIT CAVING WAS NOT ENCOUNTERED TEST PIT WAS COMPLETED AT 2.4 FEET ON 3/15/06 NELSON GEOTECHNICAL ASSOCIATES, INC. FILE NO 733906 FIGURE 8 1I co c 2 co z 0 0 co 0 0 100 90 80 70 w >- 60 m z50 w 40 U ce w 00 30 20 10 0 1000 07— p � 0 X ILADrariing 20081733908 HtraASlevesdwg 8 i I I 1 I I I I U.S. STANDARD SIEVE SIZE do 0 CDC' .goo ryoo N N COBBLES 100, 10 1.0 GRAIN SIZE IN MILLIMETERS GRAVEL COARSE ` FINE SAND COARSE MEDIUM I FINE 0.1 0.01 SILT OR CLAY 0.001 U.S.C. SYMBOL AML EXPLORATION NUMBER TP -1 SAMPLE DEPTH 9.0 feet SOIL DESCRIPTION Gray silt with trace fine sand SOIL DISTRIBUTION Gravel = 0% Sand = 3% Silt/Clay = 97% T co c m 0 1s V (D CA) CO Z c. m U) _ <�. CD o a)a. co r 0) 90/0 re 0 m 100 90 80 1— 70 w >- 60 cc z 50 1- W 40 0 ce aw 30 20 10 U.S. STANDARD SIEVE SIZE 4 �,o• +o- 0 o e 2• O•° ,9 ,p• • ,p If L [J- I- 1- >t 0 1000 100 10 1.0 GRAIN SIZE IN MILLIMETERS 1 I 1 COBBLES GRAVEL SAND 0.1 COARSE FINE COARS: MEDIUM FINE 0.01 SILT OR CLAY 0.001 U.S.C. SYMBOL •ML EXPLORATION NUMBER TP -2 SAMPLE DEPTH 2.5 feet SOIL DESCRIPTION Gray silt SOIL DISTRIBUTION Gravel = 0% Sand = 0% Silt/Clay = 100% Section 7 OTHER PERMITS Technical Information Report (TIR) 05-251 -2006 MEDAL' Consulting Engineers, Inc. IMEDINA ProjectslHirai SPIEngineering Other Permits: The project owners will obtain for a Right -Of -Way Use permit from the City of Tukwila to install drainage improvements in Pacific Highway (99), and will obtain the proper permits from King County Water District No. 49 and Valvue Sewer District for the installation of the proposed water and sanitary systems. The owners will also obtain a Clearing Grading Permit from the City of Tukwila to clear and grade the sites, and for an individual Building Permits to construct proposed homes. o0o Technical Information Report (TIR) 05-251 -2006 m2DI11d Consulting Engineers. Inc. IMEDINA ProjectsVHirai SPIEngineering City of Tukwila ESA Screening Checklist City of Tukwila Endangered Species Act Screening Checklist Date: J t -1 t RECEivE0 JUL o Applicant Name: ` + (a-- Street Address: 1 < l' AC -,,,c(? L"" City, State, Zip: z, z) eX- fir Telephone: H 0 c-(, C CA 2 o(t, 7 E: - 2--`1 s ) 'uuo DBE bE TY T Directions This Screening Checklist has been designed to evaluate the potential for your project to result in potential "take" of Chinook salmon, Coho salmon, or Cutthroat trout as defined by Section 9 of the Endangered Species Act. The checklist includes a series of "Yes" or "No" questions about your project, organized into four parts. Starting with Part A on Page 1, read each question carefully, circle "Yes ", or "No," and proceed to the next question as directed by the checklist. To answer these questions, you may need to refer to site plans,. grading and drainage plans, critical areas, studies, or other documents you have prepared for your project. The City will evaluate your responses to determine if "take" is indicated. January 25, 2001 ii Part A: Please review and answer each question carefully. Consider all phases of your project including, but not limited to, construction, normal operation, potential emergency operation, and ongoing and scheduled maintenance. Continue to the next question as directed for each No or Yes answer. 1 -0 Will the project require any form of grading? Grading is defined as any excavating, filling, clearing, or creation of impervious surface, or any combination thereof, which alters the existing ground surface of the earth (TMC 18.06.370). Please circle appropriate response. NO - Continue to Question 2 -0 (_E__ " ontinue to Question 1 -1 (Page 3) 2 -0 Will the project require any form of clearing? Clearing means the removal or causing to be removed, through either direct or indirect actions, any vegetation from a site (18.06.145). Please circle appropriate response. NO - Continue to Question 3 -0 ES Continue to Question 2 -1 (Page 4) 3 -0 Will the project require work, during any time of the project, below the ordinary high water mark of a watercourse or the Green/Duwamish or Black Rivers or in wetlands? Ordinary high water mark is the mark that is found by examining the bed and banks of a stream and ascertaining where the presence and action of waters are so common and usual as to distinctly mark the soil from that of the abutting upland, in respect to vegetation (see TMC Chapter 18.06, Page 18 -15). Please circle appropriate response. NO Continue to Question 4 -0 YES - Continue to Question 3 -1 (Page 5) 4 -0 Will the project result in the processing or . handling, storage, or treatment of hazardous. substances? This does not include the proper use of fuel stored in a vehicle's fuel tank. Hazardous substances are any liquid, solid, gas, or sludge, including any material, substance, product, commodity, or waste, regardless of quantity, that exhibits the characteristics or criteria of hazardous waste as defined by Washington Administrative Code 173 -303 (TMC 18.06.385). This includes fuel or other chemicals stored on -site during construction. Please circle a ropriate response. ENO - Continue to Question 5 -0 YES - Continue to Question 5 -0 5 -0 Will the project result in the withdrawal, injection, or interception of groundwater? Examples of projects that may affect groundwater include, but are not limited to: construction of a new well, change in water withdrawals from an existing well, projects involving prolonged construction dewatering, projects installing French drains or interceptor trenches, and sewer lines. For the purpose of this analysis, projects that require a geotechnical report pursuant to the requirements of TMC 18.45.060 or would require a geotechnical report if not exempt should answer Yes. Please circle appropriate response. NO - Continue to Question 6 -0 YES Continue to Question 6 -0 N: \Planning Forms \Applications \SEPAAPP.doc A 061 4. 2006 Part A (continued) City of Tukze ESA Screening Checklist 6 -0 Will the project involve landscaping or re- occurring outdoor maintenance that includes the regular use of fertilizers, pesticides, or herbicides? This does not include the one -time use of transplant fertilizers. Landscaping means natural vegetation such as trees, shrubs, groundcover, and other landscape materials arranged in a manner to produce an aesthetic effect appropriate for the use of the land (TMC 18.06.490). For the purpose of this analysis, this includes the establishment of new lawn or grass. Please circle appropriate response. NO— Checklist Complete Checklist Complete Part B: Please answer each question below for projects that include grading. Review each question carefully, considering all phases of your project including, but not limited to construction, normal operation, potential emergency operation, and ongoing and scheduled maintenance. Continue to the next question as directed for each No or Yes answer. 1 -1 Will the project involve the modification of a watercourse bank or bank of the Green/Duwamish or Black Rivers between the ordinary high water mark and top of bank? This includes any projects that will require grading on any slope leading to a river or stream, but will not require work below the ordinary high water mark. Work below the ordinary high water mark is covered in Part C. Please circle appropriate response. ontinue to Question 1 -2 YES - Continue to Question 1 -2 1 -2 Could the construction, operation, or maintenance of the project result in sediment transport off site or increased rates of erosion and/or sedimentation in watercourses, the Green/Duwamish rivers, or the Black River? Most projects that involve grading have the potential to result in increased erosion and/or sedimentation as a result of disturbances to the soil or earth. If your project involves grading and you have not prepared a Temporary Erosion and Sedimentation Control Plan specifically designed to retain 100 percent of the runoff (including during construction) from impervious surface or disturbed soils, answer Yes to this question. If your project is normally exempt under the Tukwila Municipal Code and would not require the preparation of a Temporary Erosion and Sedimentation Control Plan, BUT may still result in erosion or sediment transport off site or beyond the work area, answer Yes to this question. J ase circle appropriate response. Continue to Question 1 -3 S - Continue to Question 1 -3 1 -3 Will the project result in the construction of new impervious surfaces? Impervious surfaces include those hard surfaces which prevent or restrict the entry of water into the soil in the manner that such water entered the soils under natural conditions prior to development; or a hard surface area that causes water to run off the surface in greater quantity or at an increased rate of flow from the flow presented under natural conditions prior to development. Such areas include, but are not limited to, rooftops, asphalt or concrete paving, compacted surfaces, or other surfaces that similarly affect the natural infiltration or runoff patterns existing prior to development (TMC 18.06.445). Please circle appropriate response. NQ - Continue to Question 2 -0 (Page 2) CESD Continue to Question 1 -4 Part B (continued) City of Tukwila ESA Screening Checklist . • 1 -4 Will your project generate stormwater from the creation of impervious surfaces that will not be infiltrated on site? For the purpose of this analysis, infiltration includes the use of a stormwater treatment and management system intended to contain all stormwater on site by allowing it to seep into pervious surface or through other means to be introduced into the ground. If your project involves the .construction of impervious surface and does not include the design of a stormwater management system specifically designed to infiltrate stormwater, answer Yes to this question. Please circle appropriate response. CICIO -Continue to Question 2 -0 (Page 2) YES - Continue to Question 2 -0 (Page 2) Part C: Please review each question below for projects that include clearing. Review each question carefully, considering all phases of your project including, but not limited to construction, normal operation, potential emergency operation, and ongoing and scheduled maintenance. Continue to the next question as directed for each No or Yes answer. 2 -1, Will the project involve clearing within 200 feet of the ordinary high water mark of a watercourse or the Green/Duwamish or Black Rivers? Please circle appropriate response. N 7Continue to Question 3 -0 (Page 2) YES - Continue to Question 2 -2 2 -2 Will the project involve clearing of any trees within 200 feet of the ordinary high water mark of a watercourse or the Green/Duwamish or Black Rivers? A tree is defined by TMC 18.06.845 as any self - supporting woody plant, characterized by one main trunk, with a potential diameter - breast- height of 2 inches or more and potential minimum height of 10 feet. Please circle appropriate response. O -Continue to Question 2 -3 YES - Continue to Question 2 -3 2 -3 Will the project involve clearing of any evergreen trees from within 200 feet of the ordinary high water mark of a watercourse or the Green/Duwamish or Black Rivers? For the purpose of this analysis evergreen means any tree that does not regularly lose all its leaves or needles in the fall. Please circle appropriate response. NO - Continue to Question 2 -4 - S - Continue to Question 2 -4 2 -4 Will the project involve clearing within 100 feet of the ordinary high water mark of a watercourse or the Green /Duwamish or Black Rivers? Please circle appropriate response. NO )Continue to Question 3 -0 (Page 1) YES - Continue to Question 2 -5 2 -5 Will the project involve clearing within 40 feet of the ordinary high water mark of a watercourse or the Green/Duwamish or Black Rivers? Please circle appropriate response. Continue to Question 3 -0 (Page 2) YES - Continue to Question 3 -0 (Page 2) • City of Tula. ESA Screening Checklist Part D: Please review each question below for projects that include work below the ordinary high water mark of watercourses or the Duwamish /Green or Black Rivers or in wetlands. Review each question carefully, considering all phases of your project including, but not limited to, construction, normal operation, potential emergency operation, and ongoing and scheduled maintenance. Continue to the next question as directed for each No or Yes answer. 3 -1 Will the project involve the direct alteration of the channel or bed of a watercourse, the Green/Duwamish rivers, or Black River? For the purpose of this analysis, channel means the area between the ordinary high water mark of both banks of a stream, and bed means the stream bottom substrates, typically within the normal wetted -width of a stream. This includes both temporary and permanent modifications. Please circle appropriate response. Ci) - Continue to Question 3 -2 YES - Continue to Question 3 -2 3 -2 Will the project involve any physical alteration to a watercourse or wetland connected to the Green/Duwamish River? For the purpose of this analysis, "connected to the river means" flowing into via a surface connection or culvert, or having other physical characteristics that allow for access by salmonids. This includes impacts to areas such as sloughs, side channels, remnant oxbows, ditches formed from channelized portions of natural watercourses or any area that may provide off channel rearing habitat for juvenile fish from the Duwamish River. This includes both temporary construction alterations and permanent modifications. Watercourses or wetlands draining to the Green/Duwamish River that have a hanging culvert, culvert with a flap gate, diversion, or any entirely man -made or artificial structure that precludes fish access she d answer Yes to this question. Please circle appropriate response. NO - Continue to Question 3 -3 S - Continue to Question 3 -3 3 -3 . Will the project result in the construction of a new structure or hydraulic condition that could be a barrier to salmonid passage within the watercourse or the Green/Duwamish or Black Rivers? For the purpose of this analysis, a barrier means any artificial or human modified structure or hydraulic condition that inhibits the natural upstream or downstream movement of salmonids, i - . ding both juveniles and adults. Please circle appropriate response. NO - Continue to Question 3 -4 YES - Continue to Question 3 -4 3 -4 Will the project involve a temporary or permanent change in the cross - sectional area of a watercourse or the Green /Duwamish or Black Rivers? For the purpose of this analysis, the cross - sectional area is defined as a profile taken from the ordinary high water mark on the right ,bank to the ordinary high water mark on the left bank. Please circle appropriate response. O - Continue to Question 3 -5 S - Continue to Question 3 -5 3 -5 Will the project require the removal of debris from within the ordinary high water mark of a watercourse or the Green /Duwamish or Black Rivers? For the purpose of this analysis, debris includes, but is not limited to fallen trees, logs, shrubs, rocks, piles, rip -rap, submerged metal, and broken concrete or other building materials. Projects that would require debris removal from a watercourse or the Green /Duwamish or Black Rivers as part of a maintenance activity should answer Yes to this question. Please circle appropriate response. - Continue to Question 3 -6 YES - Continue to Question 3 -6 City of Tukwil A Screening Checklist 3 -6 Will the project result in impacts to watercourses or wetlands that have a surface connection to another watercourse-or the Green/Duwamish or Black Rivers but do not contain habitat conditions that support salmonid use? Such areas may include, but not be limited to hillside seeps and wetlands isolated from the watercourse or river that have a surface water connection to the watercourse or river but are not assessable, nor would be assessable to salmonids under natural conditions. Wetlands with a "functions and values" rating for baseflow /groundwater support of 9 and above (or moderate) as described in Cooke (1996) should be included. Please circle appropriate response. NC Continue to Question 3 -7 YES - Continue to Question 3 -7 3 -7 Will the project include the construction of artificial waterways or wetlands connected to a watercourse containing salmonids? For the purpose of this analysis, the construction of artificial waterways or wetlands includes wetlands, channels, sloughs, or other habitat feature created to enhance wildlife use, particularly waterfowl use, or may be attractive to wildlife, particularly waterfowl. Please circle appropriate response. ontinue to Question 3 -8 YES - Continue to Question 3 -8 3 -8 Will the project include bank stabilization? For the purpose of this analysis, bank stabilization includes, but is not limited to, rip -rap, rock, log, soil, or vegetated revetments, ,concrete structures, or similar structures. Please circle appropriate response. NO -'Continue to Question 4 -0 (Page 2) YES - Continue to Question 4 -0 (Page 2) STATE ENVIRONMENTAL CHECKLIST Please respond to all questions. Use separate sheets as necessary. Applicant Responses: A. BACKGROUND 1. Name of proposed project, if applicable: C c +Gl i c.J 2. Name of Applicant: 3. Date checklist prepared: e 4. Agency requesting checklist: City of Tukwila 5. Proposed timing or schedule (including phasing, if applicable): 1 k; oz) . / _j n7 0Y 6. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. 7. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. wr 8. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. tit Agency Comments P: \Planning Forms \ Applications \SEPAAPP.Joi April 4, 2006 Please respond to all questions. Use separate sheets as necessary. Applicant Responses: 9. List any government approvals or permits that will be needed for your proposal. N ot,-19 At O E.a. Nl 10. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to. describe certain aspects of your proposal. You do not need to repeat those answers on this page. C V e44%.1 A S•'(712.-4va a c) gy.t C. /$1? vo�S re; al gVaa144.$ 1 // 1 ' S 11. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, the tax lot number, and section, township, and range. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. S Lt. 1-1 oic- S 13i,tic� S� 4 /4y60 ("Ae___ 12. Does the proposal lie within an area designated on the City's Comprehensive Land Use Policy Plan Map as environmentally sensitive? - Agency Comments Please respond to all questions. Use separate sheets,as necessary. Applicant Responses: B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site (circle one): Flat, rolling, hilly, steep slopes, mountainous, other: Agency Comments b. What is the .steepest slope on the s'te D s-�r• 7o 9 CAM roximate percent slope)? L47 2ility c.. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. c c) n, , J q�..�Z s ( d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill. _S Au Q ;:cion (t , t`/ / ut co Y. l yflr.,ty ra-IL_ est /tdi /tf Please respond to all questions: Use separate sheets as necessary. Applicant Responses: f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. p ..Ybs, -ant /�-. , �4 'fi / c•-4_,e ..11 M p S er1J t _cA-- 9 i1 C � i.'1 About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? Agency Comments h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any` : Go °eVin� 32?6,,99° l 144, L?,v;Lczl�p�01_ C42t t/a v f /t raj �C [s'+t J/• c); .37 c,CN- b ii -v '� t5 L (� / , Q,d I1LS t d i�C.�` hi,,� ,�U' nt,t�-, C � e� %t l' f1rv-re ,�CJ� 5, (t 9-wc s c� v �� ` gco 1 2. Air a. What types of emissions to the air would result from the proposal (for example, dust, automobile odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. nail Y le ak A_411 S i 'r Gc-C .f' Al etNiCb tet c74, filnA-,Y •-C y )244GLs1 b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. rlb Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments c. Proposed measures to reduce or control emissions or other impacts to air, if any: o 3. Water a. Surface: 1. Is there any surface water body on or in the immediate vicinity of the site (including year -round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. 2. Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. 3. Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. hi0Ai.7 Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 4. Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities, if known: • 5. Does the proposal lie within a 100 -year floodplain? If so, note location on the site plan. 6. Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. u• b. Ground: 1. Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and "approximate quantities, if known. nl v Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 2. Describe waste materials that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage; industrial, containing the following chemicals...; agricultural; etc). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve: c. Water Runoff (including storm water): 1. Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow? Will this water flow. i nnto other waters? If so, describe. i- 2. Could waste materials enter ground or surface waters? If so, generally describe. d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 4. Plants a. Check or circle types of vegetation found on the site: b. What kind and amount of vegetation will be removed or altered? c. List threatened or endangered species known to be on or near the site. n.,0 Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: Deciduous tree: alder, maple, aspen, other Evergreen tree: firkcedaj pine, other (p i_+-e' Shrubs ' b g, lea ras� Pasture Crop or grain Wet soil plants: cattail, buttercup, bulrush, skunk cabbage, other Water plants: water lily, eelgrass, milfoil, other Other types of vegetation r "-i>, P u-,;,, 1 4,,,,,e,„a b. What kind and amount of vegetation will be removed or altered? c. List threatened or endangered species known to be on or near the site. n.,0 Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: 5. Animals a. Circle any birds or animals which have been observed on or near the site or are known to be on or near the site: Birds: Mammals Fish Other Hawk, heron, eagle, songbirds, other: Deer, bear, elk, beaver, other: Bass, salmon, trout, herring, shellfish, other: b. List any threatened or endangered species known to be on or near the site. c. Is the site part of a migration route? If so, explain. A6v d. Proposed measures to preserve or enhance wildlife, if any: Airritt Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Agency Comments 14 /4 7 -v VS L. .66-1" yc M t u 27? j/ �1 Q r9 i�r -b `E" vf1 i7�I �1.�cow h) Cd eu-C.-- Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. s c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: /J o V 30"►0 c � t �v A -i-wi 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. Plp 1. Describe special emergency services that might be required. 040,02. 2. Proposed measures to reduce or control environmental health hazards, if any: rIDA1 J Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Noise 1. What types of noise exist in the area which may affect your project (for example: traffic, equipment, operatiion, other)? G. �� Xv fig 7 /� /J- �S 2. What types and levels of noise would be created by or associated with the project on a short -term or long -term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. dt V rcn 4-4- em.,v s lL✓wGf4sro� -( A v < �,LS i.0 ran ss��.e,✓ /44-, 3. Proposed measures to reduce or control noise impacts, if any: 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? ies? � d ,12 I UGC, t 9 b. Has the site been used for agriculture? If so, describe. Please respond to all questions. Use separate sheets as necessary. Applicant Responses: c. Describe any structures on the site. d. Will any structures be demolished? If so, what? At e. What is the current zoning classification of the site? 6,Jq vt.srkuc f. What is the current comprehensive plan designation of the site? AID 9 g. If applicable, what is the current shoreline master program designation of the site? h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. Al Agency Comments Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments i. Approximately how many people would reside or work in the completed project? 20 j• Approximately how many people would the completed project displace? bkifv k. Proposed measures to avoid or reduce displacement impacts, if any: M 47- /0 y .e rc et tc_ 1. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low - income housing? w,'LI j /ft tli�i� -C� Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low - income housing. c. Proposed measures to reduce or control housing impacts, if any: Nal U 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? b. What views in the immediate vicinity would be altered or obstructed? VA-L/1 vazo Cr Aat-t e 9 c. Proposed measures to reduce or control aesthetic impacts, if any: Ai 62-Ai‘2 Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 1.1. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? nJnnre_._ b. Could light or glare from the finished project be a safety hazard or interfere with views? c. What existing off -site sources of light or glare may affect your proposal? d. Proposed measures to reduce or control light and glare impacts, if any: 12. Recreation a. What designed and informal recreational opportunities are in the immediate vicinity? Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Would the proposed project displace any existing recreational uses? If so, describe. ivt o c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: 13. Historic and Cultural Preservation a. Are there any places or objects listed on, or proposed for, National, State, or Local preservation registers known to be on or next to the site? If so, generally describe. b. Generally describe any landmarks or evidence of historic, archaeological, scientific; or cultural importance known to be on or next to the site. c. Proposed measures to reduce or control impacts, if any: A / /fr- Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 14. Transportation a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans; if any. b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? c. How many parking spaces would the completed project have? How many would the project eliminate? �NG /t%a 244 ri,/ , ,P/4./ 1 d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private). / (/),14‘ t P crvzJ� d- I I) cc9<af) c� e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would,occur. Z g. Proposed measures to reduce or control transportation impacts, if any: rue 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe. b. Proposed measures to reduce or control direct impacts on public services, if any. hi 0.'2._ 16. Utilities a. Circle utilities currently available at the site: efuse service, telephone, septic Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. (. 24ftrV LC✓ I I I ( it l t� C. A( a ,4 . ,-I l 1. / 11-c91,-;t2--S- kti / N, r ti—i 11,41,_ A ©aCJ�A— S /'f �e,S y4 C V u e CCe�w D I sT (z� ivl i) o 'Pw C. SIGNATURE The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relyip on them to make its r ecision. Signature: �s- Date Subn4itted: (NON-PROJECT PROPOSALS (E.G., SUBURBAN PLANS AND ZONING CODE TEXT CHANGES) MUST COMPLETE THE FOLLOWING PAGES). Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments D. SUPPLEMENTAL SHEET FOR NON - PROJECT PROPOSALS (do not use this sheet for project actions) Because these questions are very general, it may be helpful to read them in conjunction with the list of elements of the environment. When answering these questions, be aware of the extent the proposal, or the types of activities likely to result from the proposal, would affect the item at a greater intensity or at a faster rate than if the proposal were not implemented. Respond briefly and in general terms. 1. How would the proposals be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? Proposed measures to avoid or reduce such increases are: 2. How would the proposal be likely to affect plants, animals, fish, or marine life? Proposed measures to protect or conserve plants, animals, fish, or marine life are: • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 3. How would the proposal be likely to deplete energy or natural resources? Proposed measures to protect or conserve energy and natural resources are: 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated (or eligible or under study) for governmental protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitats, historic or cultural sites, wetlands, floodplains, or prime farmlands? Proposed measures to protect such resources or to avoid or reduce impacts are: 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Proposed measures to avoid or reduce shoreline and land use impacts are: 6. How would the proposal be likely to increase demands on transportation or public service and utilities? Proposed measures to reduce or respond to such demand(s) are: 7. Identify, if possible, whether the proposal may conflict with Local, State, or Federal laws or requirements for the protection of the environment. STATE ENVIRONMENTAL CHECKLIST Please respond to all questions. Use separate sheets as necessary. Applicant Responses: A. BACKGROUND 1. Name of proposed project, if applicable: c-t &1 , ecA) 1)4744--€ :& 2. Name of Applicant: 3. Date checklist prepared: JJ2 , 0-1.=2 4. Agency requesting checklist: City of Tukwila 5. Proposed timing or schedule (including phasing, if applicable): 6(0 /1-N /JI,..4 07 o? 0c4- 6. Do you have any plans for future additions, expansion, or further activity related to or connected with this proposal? If yes, explain. Agency Comments 7. List any environmental information you know about that has been prepared, or will be prepared, directly related to this proposal. • Gg0 Tge.L - e r a rC� 1,14,\ r*Z c 8. Do you know whether applications are pending for governmental approvals of other proposals directly affecting the property covered by your proposal? If yes, explain. . P: \Planning Forms \ Applications \SEPAAPP.doc April 4, 2006 Please respond to all questions. Use separate sheets as necessary. Applicant Responses: 9. List any government approvals or permits that will be needed for your proposal. on.(sz_ •�co w �, 10. Give brief, complete description of your proposal, including the proposed uses and the size of the project and site. There are several questions later in this checklist that ask you to describe certain aspects of your proposal. You do not need to repeat those answers on this page. CM p ch2— A.60 v 0 ) InC AILwj qyacP ipt.7 vo mutt -4v dice. L . Sd Agency Comments 11. Location of the proposal. Give sufficient information for a person to understand the precise location of your proposed project, including a street address, if any, the tax lot number, and section, township, and range. If a proposal would occur over a range of area, provide the range or boundaries of the site(s). Provide a legal description, site plan, vicinity map, and topographic map, if reasonably available. While you should submit any plans required by the agency, you are not required to duplicate maps or detailed plans submitted with any permit applications related to this checklist. 5 di o cu z-d ALeAr Gc-- 5 I3 2,1.ct s r ki- O H 12. Does the proposal lie within an area designated on the City's Comprehensive Land Use Policy Plan Map as environmentally sensitive? Please respond to all questions. Use separate sheets as necessary. Applicant Responses: B. ENVIRONMENTAL ELEMENTS 1. Earth a. General description of the site (circle one): Flat, rolling, hilly, steep slopes, mountainous, other: WN fit. - Lc'c— 6. Cc, Agency Comments b. What is the steepest slope on the s to . . .roximate percent slope)? c. What general types of soils are found on the site (for example, clay, sand, gravel, peat, muck)? If you know the classification of agricultural soils, specify them and note any prime farmland. 4--sc S4; Q74-/ L es/ e s-L,A4A se( d. Are there surface indications or history of unstable soils in the immediate vicinity? If so, describe. MO e. Describe the purpose, type, and approximate quantities of any filling or grading proposed. Indicate source of fill. 50,01e ep.(�5o1 L e) f‘ I L a/ (7c)V ANA se Y r �2� - = � l � Yd3'li' ,. 400 n Q. F1°t 62. e l ( irls V'.e. m.vva.: Please respond to all questions. Use separate sheets as necessary. Applicant Responses: f. Could erosion occur as a result of clearing, construction, or use? If so, generally describe. �¢ �° Yos�nl 1 S 1 M P c a.ni1 t -10 .�6 g. About what percent of the site will be covered with impervious surfaces after project construction (for example, asphalt or buildings)? 5-S h. Proposed measures to reduce or control erosion, or other impacts to the earth, if any: Gc�tf€ [,v ''?° Sid! 2. Air Agency Comments /( "t tweciS a7-v .�rffc0 }oohs, a. What types of emissions to the air would result from the proposal (for example, dust, automobile odors, industrial wood smoke) during construction and when the project is completed? If any, generally describe and give approximate quantities if known. r A e SY'r /`! o,\A 1 Al b. Are there any off -site sources of emissions or odor that may affect your proposal? If so, generally describe. • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments c. Proposed measures to reduce or control emissions or other impacts to air, if any: 3. Water a. Surface: 1. Is there any surface water body on or in the immediate vicinity of the site (including year -round and seasonal streams, saltwater, lakes, ponds, wetlands)? If yes, describe type and provide names. If appropriate, state what stream or river it flows into. Nn 2. Will the project require any work over, in, or adjacent to (within 200 feet) the described waters? If yes, please describe and attach available plans. 1(10 3. Estimate the amount of fill and dredge material that would be placed in or removed from surface water or wetlands and indicate the area of the site that would be affected. Indicate the source of fill material. tiok0 -(9 • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 4. Will the proposal require surface water withdrawals or diversions? Give general description, purpose, and approximate quantities, if known. 5. Does the proposal lie within a 100 -year floodplain? If so, note location on the site plan. 6. Does the proposal involve any discharges of waste materials to surface waters? If so, describe the type of waste and anticipated volume of discharge. b. Ground: 1. Will ground water be withdrawn, or will water be discharged to ground water? Give general description, purpose, and approximate quantities, if known. Ato • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 2. Describe waste materials that will be discharged into the ground from septic tanks or other sources, if any (for example: Domestic sewage; industrial, containing the following chemicals...; agricultural; etc). Describe the general size of the system, the number of such systems, the number of houses to be served (if applicable), or the number of animals or humans the system(s) are expected to serve: c. Water Runoff (including storm water): 1. Describe the source of runoff (including storm water) and method of collection and disposal, if any (include quantities, if known). Where will this water flow? Will this water flow? Will this water flow into other waters? If so, describe. !i"'4/a4k 14'O� +9 U f A,► Yct.„ 2. Could waste materials enter ground or surface waters? If so, generally describe. 4/O d. Proposed measures to reduce or control surface, ground, and runoff water impacts, if any: /4 t L • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 4. Plants a. Check or circle types of vegetation found on the site: b. What kind and amount of vegetation will be removed or altered? d k_PdVteci fl-e? 40111..a— c. List threatened or endangered species known to be on or near the site. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: Deciduous tree: alder, maple, aspen, other Evergreen tree: fir Ccedat; pine, other 60 bo_.9." -Kee, Shrubs k ras Pasture Crop or grain Wet soil plants: cattail, buttercup, bulrush, skunk cabbage, other Water plants: water lily, eelgrass, milfoil, other Other'types of vegetation nJ'iA , (.;u -u,, I + .ee d b. What kind and amount of vegetation will be removed or altered? d k_PdVteci fl-e? 40111..a— c. List threatened or endangered species known to be on or near the site. Proposed landscaping, use of native plants, or other measures to preserve or enhance vegetation on the site, if any: • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: 5. Animals a. Circle any birds or animals which have been observed on or near the site or are known to be on or near the site: Birds: Mammals Fish Other Hawk, heron, eagle, songbirds, other: Deer, bear, elk, beaver, other: Bass, salmon, trout, herring, shellfish, other: b. List any threatened or endangered species known to be on or near the site. c. Is the site part of a migration route? If so, explain. 40 d. - Proposed measures to preserve or enhance wildlife, if any: 6. Energy and Natural Resources a. What kinds of energy (electric, natural gas, oil, wood stove, solar) will be used to meet the completed project's energy needs? Describe whether it will be used for heating, manufacturing, etc. Agency Comments . ti,yrv4t 9m-s . u��-Ci- A,,,,7 ,pp rr U k �F e, w Z) 11.0 u�P hv-Co'� eW -C— • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Would your project affect the potential use of solar energy by adjacent properties? If so, generally describe. 4011-1 11,k_ 442-- 3 J'Irrl.) ktniz Arcuit c. What kinds of energy conservation features are included in the plans of this proposal? List other proposed measures to reduce or control energy impacts, if any: n CA..) "CO 7. Environmental Health a. Are there any environmental health hazards, including exposure to toxic chemicals, risk of fire and explosion, spill, or hazardous waste, that could occur as a result of this proposal? If so, describe. PIO Pr 1. Describe special emergency services that might be required. 2. Proposed measures to reduce or control environmental health hazards, if any: /,1,0,v Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Noise 1. What types of noise exist in the area which may affect your project (for example: traffic, equip1mentt,, /operation, other)? aviv ((/f 2. What types and levels of noise would be created by or associated with the project on a short-term or long -term basis (for example: traffic, construction, operation, other)? Indicate what hours noise would come from the site. �b V on 4-C, f'v`. -d -( 01 r � .r .17 a- riel VY1A1,4 i,,, • <<.==2-e.) AWL Ito m=oo yOia NDIS.2T AA -011id / 3. Proposed measures to reduce or control noise impacts, if any: /L✓t..e<)t wc/ 8. Land and Shoreline Use a. What is the current use of the site and adjacent properties? 7Ls w� 3 k-ws� tocS��L b. Has the site been used for agriculture? If so, describe. Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments c. Describe any structures on the site. d. Will any structures be demolished? If so, what? Apo e. What is the current zoning classification of the site? f. What is the current comprehensive plan designation of the site? AJ 4_ y g. If applicable, what is the current shoreline master program designation of the site? h. Has any part of the site been classified as an "environmentally sensitive" area? If so, specify. th Please respond to all questions. Use separate sheets as necess ' Applicant Responses: , Agency Comments 3. How would the proposal be likely to deplete ener ' or natural resources? Proposed measures to protect or conserve energy and natural resources are:. 4. How would the proposal be likely to use or affect environmentally sensitive areas or areas designated (or eligible or under study) for governmental protection; such as parks, wilderness, wild and scenic rivers, threatened or endangered species habitats, historic or cultural sites, wetlands, floodplains, or prime farmlands? Proposed measures to protect such resources or to avoid or reduce impacts are: vv� ,nom- at^-'2 5. How would the proposal be likely to affect land and shoreline use, including whether it would allow or encourage land or shoreline uses incompatible with existing plans? (� Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Proposed measures to avoid or reduce shoreline and land use impacts are: l -S FJJ' I S ,41(1,;.i{ #1111 Tl {re �s L L. 69f 6. How would the proposal be likely to increase demands on transportation or public service and utilities? ekikyt 8 - 4 h© vi,eLes, 44, b y e 1l /, c 2 e • klitA Chr p4Lte ,,d« b ��� � � ,� x.16 L,hcs Proposed measures to reduce or respond to such demand(s) are: . .� A. _ • r t- • /. .. • • Agency Comments 7. Identify, if possible, whether the proposal may conflict with Local, State, or Federal laws or requirements for the protection of the environment. #k)ip re, 00142.4 6t f 00' t - vmseekidtukt ic 6-e4-fc • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments i. Approximately how many people would reside or work in the completed project? S— A9 2-0 j. Approximately how many people would the completed project displace? k. Proposed measures to avoid or reduce displacement impacts, ' � if any: An t p � 1. Proposed measures to ensure the proposal is compatible with existing and projected land uses and plans, if any: 9. Housing a. Approximately how many units would be provided, if any? Indicate whether high, middle, or low - income housing? • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Approximately how many units, if any, would be eliminated? Indicate whether high, middle, or low - income housing. c. Proposed measures to reduce or control housing impacts, if any: NO 64 10. Aesthetics a. What is the tallest height of any proposed structure(s), not including antennas; what is the principal exterior building material(s) proposed? b. What views in the immediate vicinity would be altered or obstructed? VA, v(4,) tsus Vas revI -- c. Proposed measures to reduce or control aesthetic impacts, if any: • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 11. Light and Glare a. What type of light or glare will the proposal produce? What time of day would it mainly occur? b. Could light or glare from the finished project be a safety hazard or interfere with views? c. What existing off -site sources of light or glare may affect your proposal? Mb d. Proposed measures to reduce or control light and glare impacts, if any: AJOal„ Q 12. Recreation a. What designed and informal recreational opportunities are in the immediate vicinity? • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments b. Would the proposed project displace any existing recreational uses? If so, describe. c. Proposed measures to reduce or control impacts on recreation, including recreation opportunities to be provided by the project or applicant, if any: 13. Historic and Cultural Preservation a. Are there any places or objects listed on, or proposed for, National, State, or Local preservation registers known to be on or next to the site? If so, generally describe. b. Generally describe any landmarks or evidence of historic, archaeological, scientific, or cultural importance known to be on or next to the site. c. Proposed measures to reduce or control impacts, if any: A// • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments 14. Transportation a. Identify public streets and highways serving the site, and describe proposed access to the existing street system. Show on site plans, if any. b. Is the site currently served by public transit? If not, what is the approximate distance to the nearest transit stop? c. How many parking spaces would the completed project have? How many would the project eliminate? /A94/2— n �, 244 F / ry ,0�5/ d. Will the proposal require any new roads or streets, or improvements to existing roads or streets, not including driveways? If so, generally describe (indicate whether public or private). / pin .q( e. Will the project use (or occur in the immediate vicinity of) water, rail, or air transportation? If so, generally describe. ik,6 0 Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments f. How many vehicular trips per day would be generated by the completed project? If known, indicate when peak volumes would occur. Z g. Proposed measures to reduce or control transportation impacts, if any: /4e 15. Public Services a. Would the project result in an increased need for public services (for example: fire protection, police protection, health care, schools, other)? If so, generally describe. b. Proposed measures to reduce or control direct impacts on public services, if any. M - 16. Utilities a. Circle utilities currently available at the site: efuse service, telephone, septic Please respond to all questions. Use separate sheets as necessary. Applicant Responses: b. Describe the utilities that are proposed for the project, the utility providing the service, and the general construction activities on the site or in the immediate vicinity which might be needed. c Arrt/ / I l 6r/4 `a. 6 K a ft °v9 / L [s -P)-e v, 1 vice c ., Qls-r (K ) co() C. SIGNATURE The above answers are true and complete to the best of my knowledge. I understand that the lead agency is relyi w on them to make its ecision. Signature: Date Sub itted: (NON- PROJECT PROPOSALS (E.G., SUBURBAN PLANS AND ZONING CODE TEXT CHANGES) MUST COMPLETE THE FOLLOWING PAGES). Agency Comments • • Please respond to all questions. Use separate sheets as necessary. Applicant Responses: Agency Comments D. SUPPLEMENTAL SHEET FOR NON - PROJECT PROPOSALS (do not use this sheet for project actions) Because these questions are very general, it may be helpful to read them in conjunction with the list of elements of the environment. When answering these questions, be aware of the extent the proposal, or the types of activities likely to result from the proposal, would affect the item at a greater intensity or at a faster rate than if the proposal were not implemented. Respond briefly and in general terms. 1. How would the proposals be likely to increase discharge to water; emissions to air; production, storage, or release of toxic or hazardous substances; or production of noise? Proposed measures to avoid or reduce such increases are: 2. How would the proposal be likely to affect plants, animals, fish, or marine life? Proposed measures to protect or conserve plants, animals, fish, or marine life are: x x CYCLONE FENCE 1W = 200 \ BW =199 N TIN = BW = 200 17.25' X 52' X 10' Combined Wet - R/D Vault \(See Detail Sht. C5) = 203.8 BW = 202.0 Concrete Wall Max. Height = 1.8' x •. 0 00" OF pis 2 c C/A/p. , 32s, „I 62.24' .x ow 1 N 6•'40'00" E 7:.i7' 50' x • TW = 205.8 BW = 204.0 1W =207.0 BW = 206.0 n K.0'cT wq(4 N, 194 50' Install 3/4" Water Meters Per King County Water Dsltrict No. 125 Standards. (5 Meters rs TYP.) icatiottsting water main In S. 132nd Street as shown hereon fs approximate, Tact must field verify horizontal and vertical' ations of existing water line and all other existing utillUes prior to constru�lon. ', _ e / AE / 15 CA) R, 12 12 -� Sc �ti 24 8 p • R = 10' (TYP.) • EDGE OF ASPHALT t 1_ OHP I]HP ss 1cD Ew � &• s�,E, SD R /4,/ a,