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17-105848RETURN TO: PW ADMIN VvleyuAl.S EXT: 2700 ID #: CITY OF FEDER,.-u WAY LAW DEPARTMEN'i ROUTING FORM ORIGINATING DEPT/DIv: PUBLIC WORKS / D Q. mou4-1+ G�S ORIGINATING STAFF PERSON: EXT: Z 3. DATE REQ. BY: 1. TYPE OF DOCUMENT (CHECK ONE): ❑ CONTRACTOR SELECTION DOCUMENT (E.G., RFB, RFP, RFQ) ❑ PUBLIC WORKS CONTRACT ❑ SMALL OR LIMITED PUBLIC WORKS CONTRACT ❑ PROFESSIONAL SERVICE AGREEMENT ❑ MAINTENANCE AGREEMENT ❑ GOODS AND SERVICE AGREEMENT ❑ HUMAN SERVICES / CDBG ❑ REAL ESTATE DOCUMENT > SECURITY DOCUMENT (E.G. BOND RELATED DOCUMENTS) ❑ ORDINANCE ❑ RESOLUTION S a-}'" t37'j 0'��r�A ❑ CONTRACT AMENDMENT (AG#): ❑ INTERLOCAL ,�� ikwis Gum+. S L PROJECT NAME: i. NAME OF CONTRACTOR: ADDRESS: Z+4 W:;' SIGNATURE NAME: LL C FAX: TITLE: EXHIBITS AND ATTACHMENTS: ❑ SCOPE, WORK OR SERVICES ❑ COMPENSATION ❑ INSURANCE REQUIREMENTS/CERTIFICATE ❑ ALL OTHER REFERENCED EXHIBITS PROOF OF AUTHORITY TO SIGN ❑ REQUIRED LICENSES ❑ PRIOR CONTRACT/AMENDMENTS CFW LICENSE # BL, EXP. 12/31/ UBI # , Exp• 1 1 F. TERM: COMMENCEMENT DATE:, COMPLETION TOTAL COMPENSATION: $ — 0 — (INCLUDE EXPENSES AND SALES TAX, IF ANY) (IF CALCULATED ON HOURLY LABOR CHARGE - ATTACH SCHEDULES OF EMPLOYEES TITLES AND HOLIDAY RATES) REIMBURSABLE EXPENSE: ❑ YES ❑ NO IF YES, MAXIMUM DOLLAR AMOUNT: S IS SALES TAX OWED: ❑ YES ❑ NO IF YES, $ PAID BY: ❑ CONTRACTOR ❑ CITY RETAINAGE: RETAINAGE AMOUNT: ❑ RETAINAGE AGREEMENT (SEE CONTRACT) OR ❑ RETAINAGE BOND PROVIDED ❑ PURCHASING: PLEASE CHARGE TO: DOCUMENT / CONTRACT REVIEW 'PROJECT MANAGER DIVISION MANAGER V DEPUTY DIRECTOR �L?IRECTOR /❑ RISK MANAGEMENT (IF APPLICABLE) )CLAW DEPT COUNCIL APPROVAL (IF APPLICABLE) INITIAL/ DATE REVIEWED IAA ►• V R INITIAL / DATE APPROVED SCHEDULED COMMITTEE DATE: COMMITTEE APPROVAL DATE: SCHEDULED COUNCIL DATE: COUNCIL APPROVAL DATE: 1. CONTACT SIGNATURE ROUTING ❑ SENT TO VENDOR/CONTRACTOR DATE SENT: 4949 &ej DATE REC'D: o-lalm ❑ ATTACH: SIGNATURE AUTHORITY, INSURANCE CERTIFICATE, LICENSES, EXHIBITS ❑ CREATE ELECTRONIC REMINDERINOTIFICATION FOR 1 MONTH PRIOR TO EXPIRATION DATE (INCLUDE DEPT. SUPPORT STAFF IF NECESSARY AND FEEL FREE TO SET NOTIFICATION MORE THAN A MONTH IN ADVANCE IF COUNCIL APPROVAL IS NEEDED.) INITIAL / DATE SIGNED ❑ FINANCE DEPARTMENT ❑ LAW DEPT ❑ SIGNATORY (MAYOR OR DIRECTOR) ❑ CITY CLERK ❑ ASSIGNED AG # ❑ SIGNED COPY RETURNED ❑ RETURN ONE ORIGINAL AG# DATE SENT: *XECM " TS: y RL..J _ y 5 :7CECUTE ORIGINALS (r� 1 IMI R RECEIVED �. DEC,� 2a�� CIPERMIT APPLICATION awTY OF i. J 1W Federal Allay PERMIT CENTER + 33325 8w Avenue South + Federal Way, WA 98003-6325 253-835-2607 + FAX 253-835-2609 + rear inccnrcrrdein o6edernYuar,00m CITY OF FEDERALWAIT COMMUNFN DEVELoPME T k PERMST NUMBER I —7— ' V — T — — U BLt 0 BIT& ADDRESS , PROJF.C'r VALIIATION ZONING Afi8E860R'BTA7C1PAii i2cc;> 1 SG -4- -L TYPE OF PERMIT 'BUILDING ,(PLUMBING gMECHANICAL ❑ DEMOLITION ❑ ENGINEERING ❑ FIRE PREVENTION NAME OF PROJECT PROJECT DESCRIPTION Detailed descnption of Mork to be included on this permit only PROPERTY OWNER CONTRACTOR APPLICANT PROJECT CONTACT (Tile individual to receive and respond to all correspondence concerning this application) PROJECT FINANCING When value is $5,000 or more (RCW 19.27.095) IL - UP A6 MiNaoe ISAILLNO ADF3RnAS� VI.R17E �k•W'C _`r 1115 - � ATE a7q HAME115 / + DIALLING ADDRESS CITY WA STATE cONTRACTOWS LICENSE 9 MLiNG ADDRE98 r �gaTa r- NAME MAILING ADDRESS clTr NAME ��1►�'^ I�i S F7A i 4&—/ SIAILING ADS)RESS, CITY, STATE, ZIP STATE I ZIP ERPIRATION DATE f l o STATE I ZIP N A oZL5 i59 -5q5 PHONE E-MAII. FAX FEDERAL WAY BUSINESS LICENSE i PRIMARY PHONE 2 17+ ► 7—I. �E-MAI, FA - PRIMARY PHONE E-MAI. FAX ❑ OWNER -FINANCED PECTIM owner'. I certify that to the hest 1 certify under penalty of pcilury t at 1 am the property owner or auC ❑ agent of the property pJ of any knowledge, the information submitted in support of this permit application is true and correet. I certify that 1 will comply with all applicable City of Federal Way regulations pertaining to the murk authorised by the issuance of a permit- 1 understand that the issuance of this permit does not remove the owner's responsibility for compliance with local, state, or federal taws rcgutatirtg construction a environmental Iaws. I further agree to hold harmless the City of Federal Way as to any claim (including costs, expenses, and attorneys' fees incurred in tire inocatdgation and defame of such claim!, which mag be made by any person, including the undersigned, and filed against the city, but only where such claim. arises out of the reliance of the city. including {es officers and employeea, upon the accuracy of the information supplied to the cpart o i{ appli atie /f SIGNATURE: IZI'617— _DATE �I / II 7 PRINT NAME: -FA�4- Z FFI Bulletin #100 — January 29, 2016 Page I of 2 k:lHandouts%Petmit Application MECHANICAL PERMIT Ittdicaie how rnan o each i e o 'tWe to be installed orrelaaated AIR HANDLING UNITS FANS AIR CONDITIONER FIREPLACE INSERTS BOILERS FURNACES COMPRESSORS GAS LOG SETS DUCTING GAS PIPING VALUE OF MECHANICAL WORK $ SS, oo a ti ueis ro" cL Da not include exrs[vr !ores to remain. GAS PIPE OUTLETS OTHER (Describe) HOODS (commercial) HOT WATER TANKS REFRIGERATION SYST WOODSTOVES PLUMBING PERMIT Ind haul mare o each t e o yure to be instafied or relocated as art o this pro' cL Do not in BATHTUBS (oc nt6/ehoaer Com6oj LAVS (Nand Sint.! TOILETS DISHWASHERS RAINWATER SYSTEMS URINALS DRAINS SHOWERS VACUUM BREAKERS DRINKING FOUNTAINS HOSE BIBBS SINKS (IGtdran/ut1itA( WATER HEATERS (Electric{ SUMPS WASHING MACHINES GENERAL INFORMATION CM =TRICALAREA"oPROPJRMl WATER PtrRYE7(OR MQ=TNffJPR. _"oos USE LOT St2$ pa equ a t N4& VALUE OFPLUMBING WORK $ W, oo� We exislin Lures to rem.abt �: WATER PIPING OTHER (Describe) SEWER �W4� W ` VALUE OF TOTAL FIXTURES E706TIHn FIRE SPRiNKI,pR SYSTEM? PROPOSED FIRS SUPPREMog SYSTSW ❑ Yes i No )(Yes ❑ No RESIDENTIAL - NEW OR ADDITION AREA DESCRDPTION (in square feet) EXISTING PROPOSED BASEMENT FIRST FLOOR (or Mobile Home) ? SECOND FLOOR COVERED ENTRY DECK GARAGE ❑ CARPORT ❑ OTHER (desall,4 Area Totals =zTnz **jv Aw1,f1; aJa� r,7 ESTIMATED SELLING PRICE $ 11 ` I # OF BEDROOMS COMMERCIAL -- NEWJADDITION AREA W CRIPTION Area in S uare Feet ancy Group(s) B--,nYG O ;CUP M ADDITION COMMERCIAL — REMODEUTENANT IMPROVEMENTS AREA DESCRIPTION Area B uare Fineet Occupancy Groups) TOTAL BUILDING TENANT AREA ONLY PROmmAREA ONLY — TOTAL I FOR OFFICE USE IWw asnulctlan # of Stories Additional Information Construction —F # Additional Information Bulletin #100 - January 29, 2016 Page 2 of 2 k:lHandoutslPermit Application CITY ❑F �. Federal February 20, 2018 Weaver Architects Paul Grundhoffer 1411 4th Ave, Suite 810 Seattle, WA 98101 Re: Permit #17-105848-00-Co; Pacific Dental Building, Ixx Sw Campus Dr, Federal Way Dear Mr. Grundhoffer: CITY HALL 33325 8th Avenue South Federal Way, WA 98003-6325 (253) 835-7000 www.cityoffederalway.com Jim Ferrell, Mayor The Public Works Department has reviewed the first submittal of civil plans for Pacific Dental (Federal Way Commercial Lot B). Please make the following revisions and/or additions: Technical Information Report Section 1 Project Overview The entire parcel is subject to water quality requirements, per Federal Way Revised Code Section 19.30.120, regardless of it being new or existing pavement. Also see the Federal Way Addendum to the KCSWDM Section 1.2.8. Please revise the TIR, conveyance system, and water quality system accordingly. Note: the KCSWDM provides for a reduction to Basic Water Quality if one of the five exceptions applies to the site. Exception ##4 may apply to the existing parking area. Core Requirement #7 2. A bond is required for this project. See document section of this letter. Core Requirement #9 3. Where is the soil amendment shown in the plans? 4. Looking at the detention vault sizing calculations "new structure" sizing, the dimensions correspond to the plans except for the length, which is 135' in the calculations on page 25 (hand lettering), 105' on page 21, and 31' in the plans. Please provide additional explanation of the vault sizing calculations in this section so that the size is quickly and easily understood. \\CF WFILE 1 \Applications\CSDC\PROD\docs\save\ 149213_77302_15113638.DOC Sheet TP2 16. In Section A -A', show the existing grade for the existing parking area that has a proposed grade of 2.82%. Indicate if this is overlay or replacement. Documents 17. Please complete and return the enclosed bond information worksheet and bond quantities worksheet. The City will prepare the actual document for signatures. 18. Please provide an abbreviated legal description and a full legal description of the property. The full legal description will be attached to the license, so must be formatted on 8.5 x 11 and meet King County recording requirements. Please provide one set of revised civil plans for review. The TIR, document worksheets, and legal descriptions may be returned via email or one set may be submitted with the revised plans. Other departments will provide separate review of this project. Sincerely, Ann Dower Senior Engineering Plans Reviewer Enc: Bond Information Worksheet; Bond Quantities Worksheet cc: Jeff Cederholm, P.E.; Larson and Associates; 9027 Pacific Avenue, Suite 4; Tacoma, WA 98444 Project File/ad Day File \\CFWFILEI\Applications\CSDC\PROD\docs\save\149213.77302_15113638.DOC �k�CITY OF ... Federal Way .2ntered on Opportunity September 4, 2018 Federal Way Covenant Group LLC 17000 Red Hill Ave Irvine, CA 92614 CITY HALL 33325 8th Avenue South Federal Way, WA 98003-6325 (253) 835-7000 www. cityoffederalway.. com Jim Ferrell, Mayor RE: Permit #17-105848-00-CO; PACIFIC DENTAL BUILDING SHELL, 164 SW Campus Dr, Federal Way Wet Weather Construction Requirements Dear Federal Way Covenant Group LLC: The wet weather season officially begins on October 1 t. Any site with exposed soils is subject to the 'Wet Season Requirements' per the King County Surface Water Design Manual, Appendix D, page D-113. Specifically, please note that the allowed time that a disturbed area may- remain unworked without cover is reduced to two (2) consecutive work days and that stockpiles and steep cuttfill slopes are to be protected if unworked for more than twelve (12) hours. Additionally, all areas that are to be unworked during the wet season shall be seeded within one (1) week of the start of the wet season. Please review any site specific requirements, instructions, notes, and details that are included on your approved plans. Some sites have wet weather restrictions that prohibit certain construction activities. These also will be noted on the plans. Also, as a reminder, the approved City of Federal Way work hours are listed below. Work outside of the approved hours requires prior approval. Monday through Friday: ■ Outside Right of Way: 7:00 AM through 8:00 PM ■ Inside Right of Way: 8:30 AM through 3:00 PM Saturday: • Outside Right of Way: 9:00 AM through 8:00 PM • Inside Right of Way: No work is permitted Sunday: • No work is permitted ■ City Observed Holidays: • No work is permitted If you have any questions, please do not hesitate to contact either George Hauser at 253-835-2741 or me at 253- 835-2732. Sincerely, � V Ann Dower Senior Engineering Plans Reviewer cc: George Hauser, Public Works Construction Inspector Powell Construction Co.; attn.: Jon Sellar, Project Manager; 2625 Northup Way; Bellevue, WA 98004 Project File/AD Day File \\CFW FILE1 \Applications\CSDC\PROD\dots\save\149213_78215_04112319.DOC 8/2/2018 Landmark Web Official Records Search r Instrument Number: 20180515000670 Record Date:5/15/2018 11:54 AM King County, WA Document:COV Rec: $79.00 Page-1 of 6 Recording Requested By: Federal Way Covenant Group LLC When Recorded Mail To: City of Federal Way 33325 8th Ave S Federal Way, WA 98003 Attn: Ann Dower, Public Works Dept *4>0 DECLARAaN OF COVENANT Prohibiting Use of Leachable Metals and Access Easement Grantor (s): FEDERAL WAY COVENANT GROUP LLC, a Nevada limited liability company EP FEDERAL WAY LLC, a Nevada limited liability company Grantee (s): CITY OF FEDERAL WAY, a Washington municipal corporation Property Legal Description (abbreviated): Lot "B" of City of Federal Way Boundary Line Adjustment No. 13-104768-00-SU, recorded under recording number 20131224900009, in King County, WA. Complete Legal Description indicated below. Assessor's Tax Parcel ID#(s): 415920-0715 IN CONSIDERATION OF the approved City of Federal Way ("City") building permit for application No. 17-105848-00-CO relating to real property legally described as: Le al desen Lion of pro=y attached hereto as Exhibit "A ' and inco orated herein by reference. the undersigned as Grantor(s), declares(declare) that the above described property is hereby established as having a prohibition on the use of leachable metals on those portions of the property exposed to the weather for the purpose of limiting metals in stormwater flows and is subject to the following restrictions. The Grantor(s) hereby covenant(s) and agree(s) as follows: no leachable metal surfaces exposed to the weather will be allowed on the property. A leachable metal surface means a surface area that consists of or is coated with a non-ferrous metal that is soluble in water. Common leachable metal surfaces include, but are not limited to, galvanized steel roofing, gutters, -flashing, downspouts, guardrails, light posts, and copper roofing. The City shall have a nonexclusive perpetual access easement on the Property for ingress and egress over the Property for the sole purposes of inspecting and monitoring that no leachable metal is present on the Property. https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelld&quickSearchSelection=# 1 /6 8/2/2018 Landmark Web Official Records Search Instrulunt Number: 201805154100670 Due--tent:COV Rec: S79.00 Page-3 of 6 Record bate:5115/2018 11:54 AM King Co, .,,WA ALL-PURPOSE ACKNOWLEDGEMENT State of Nevada County of Clark On April 30, 2018, before me, Krista M. Sunjara, Notary Public, personally appeared, Christopher Aguos,,personally known to me (or proved to me on the basis of satisfactory evideyi�&) to be the person(s) whose name(s) is/are subscribed to the within instrument'and acknowledged to me that he/she/they executed the same in his/her/their authorized capacity(ies), and that by his/her/their signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acted, aexecuted the instrument. WITNESS my hand and official seal 0 (S of Notary) KRISTA M. SUNJARA Notary Public, State of Nevada k Appointment No.17-3019-t My Appt-ExpiresJun 10, 2021 (Affix seal in the above blank space) https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelld&quickSearchSelection=# 3/6 8/2/2018 Landmark Web Official Records Search Instrupent Number: 20180515000670 Dor•—+ent:C+OV Rec: $79A0 Page-5 of 6 :'yRecord Oate:5/15/2018 11:54 AM King Co, J,, WA ALL-PURPOSE ACKNOWLEDGEMENT State of Nevada County of Clark On April 30, 2018, before iue, Krista M. Sunjara, Notary Public, personally appeared, Bruce M. Kahl, personally known to me (or proved to me on the basis of satisfactory evidence) to be the person(s) whose name(s) is/are subscribed to the within instrument and acknowledged to me that he/she/they executed the same in hi5/hq/their authorized capacity(ies), and that by his/her/their signature(s) on the instrument the person(s), or the entity upon behalf of which the person(s) acteoAxecuted the instrument. WITNESS my hand and official seal 0 (Signa oFNotary) KRISfA M. SUNJARA Notary Public, State of Nevada Appointment No.17-3019-1 My Appt. Expires Jun 10, 2021 (Affix seal in the above blank space) https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelId&quickSearchSelection=# 5/6 8/2/2018 Landmark Web Official Records Search Instrument Number: 20180515000671 Record Date:5/15/2018 11:5.1 AM King Count-, WA Docuinent:COV Rec: $80.011 Page-1 of 7 Recording Requested By: FEDERAL WAY COVENANT GROUP LLC When Recorded Mail To: CITY OF FEDERAL WAY 33325 8th Ave S FLDERAL WAY, WA 98003 ATTN: Ann Dower, Public Wor %00 01 y DECLARA'19�i1N OF COVENANT .M1 Grantor (s): FEDERAL WAY COVENANT GLLC, a Nevada limited liability . 3 company �n EP FEDERAL WAY LLC, a Nevada.fimited liability company c� Grantee (s): CITY OF FEDERAL WAY, a Washingf6mmunicipal corporation Property Legal Description (abbreviated): Lot `B" of City'akFederal Way Boundary Line Adjustment No. 13-104768-00-SU, recorded under recording Limber 20131224900009, in King County, WA. Complete Legal Description indicated below- Assessor's Tax Parcel ID#(s): 415920-0715 IN CONSIDERATION OF the approved City of Federal Way ("City") building permit for application No. 17-105848-00-CO relating to real property legally described as: CL A ff -.'.. a .--....-.�..� herein -b reference. in King County, Washington, and portions of vacated streets adjoining ("Property"), the undersigned as Grantor(s) declares that the above -described Property is hereby subject to a perpetual easement for a natural or constructed storm water conveyance system ("System") and hereby dedicates, covenants, and agrees as follows: City shall have the right to ingress and egress over the Property to access such easement area for inspection of and to reasonably monitor the System for performance, operational flows or defects in accordance with the City's Surface Water Management Division procedures. https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelld&quickSearchSelection=# 1 /7 8/2/201 H Landmark Web Official Records Search Wstrumipt Number: 20180515000671 Dur ent:COV Rec: $80.00 Page-3 of 7 Record Date:545/2018 I i :ry4 AM King Cagy .j, WA GRANTOR: FEDERAL WAY COVENANT GROUP LLC By: op er Ag-uon, Authorized Signatory STATE OF NEVADA ) COUNTY OF CLARK ) On this day personally appeared bckw me .Christ6 her A to me to be the _Authorized .Sioa_tar� of the F eral k : twovenant: �rou LI.0 that ted the foregoing instrument, and acknowledged the said instrument to be the free oluntary act and deed of said limited liability company, for the uses find purposes mentioned, and on oath stated that he was authorized to execute said instrument, r.: - GIVEN my hand and official seal thi _ day of , 20 (typedlprintedname of notary) Notary Publiddri and for the State of Nevada. My oommission expires:. . https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=search Criteria Parcelld&quickSearchSeIection=# 3/7 8/2/2018 Landmark Web Official Records Search tnstrumept Number: 20180515000671 ❑nc• -ent:COV Rec: $80.00 Page-5 of 7 Record Datc:5/1512018 11:54 AM King Co► ; . WA GRANTOR: EP FEDERAL WAY LLC By: Bruce Kahl, anager STATE OF CALIFORNIA ) ) ss. COUNTY OF LOS ANGELES } On this day personally appeared before me-Briiee Kahl, to me known a the Mara er of the EP Federal Way LL_C that executed the foregoing instrument d acknowledged the said instrument to be the free and voluntary act and deed of sai mited liability company, for the uses and purposes therein mentioned, and on gal h stet t he was authorized to execute said instrument. GIVEN my hand and official sea is day of 20 (typedlpdnted name of notary) Notary Public in and for the State of California. My commission expires Rev.10117 4*'A- 'eA https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelId&quickSearchSelection=# 5/7 8/2/2018 Landmark Web Official Records Search Lnstrumgnt Dumber: 20180515000671 Due !ent:COV Rec: $80.00 Page-7 of 7 Record Date:5/15/2018 11.54 AM King Cut . j. WA EXHIBIT "A" Legal Description: LAKEWOOD KING COUNTY ADD LOT B OF FEDERAL WAY LLA# 13-104768 REC #20131224900009 SD LLA BEING LOCATED IN POR OF ELKS 6 Syf &18 & 24OF PLAT OF LAKEWOOD KING COUNTY ADD (SD LLA AKA LOTS A & 13 & D OF FEDERAL WAY- #97-0001 REC # 2000112.0900005 LESS POR FOR RD) 0 Abbreviated Legal Description: �+ LOT" B" OF CITY OF FEDERAL WAY BOUNDARY LINEf1. LISTMENT NO.13-104768-00-SU, RECORDED UNDER RECORDING NUMBER 26131224900009, IN KING COUNTY, WASHINGTON. Parcel Number: 415920-0715 0- 0 https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParceIId&quickSearchSelection=# 7/7 8/2/2018 Landmark Web Official Records Search Instrument Number: 20180515000669 Document:MISC Rec: $78.00 Page-1 of 5 Record Date:5/15/2018 11:54 AM King County, WA Return Address: City of Federal Way Attn: Ann Dower/Public Works Dept. 33325 8th Avenue South Federal Way, WA 98003-6325 LICENSE EXHIBIT 3 Grantor (s): FEDERAL WAY COVENANT GROUP LLC, a Nevada limited liability company EP FEDERAL WAY LLC, a Nevada limited liability company Grantee (s): CITY OF FEDERAL WAY, a WiaOdgton municipal corporation Property Legal Description (abbreviated): Additional Legal(s) on Exhibit A 0 Easement Legal Description (abbreviated): Lot " f City of Federal Way BLA no- 13- 104768-00-SU, Recorded under recording number 2� 24900009, King County, WA Assessor's Tax Parcel ID#(s): 415920 0715 0 The undersigned owner of certain real property 10;7&m Federal Way, Washington and legally described as follows: Legal description attached hereto as Exhibit "A" and incorporated herein by this reference ("Property") hereby grants an irrevocable license to the'City of Federal Way ("City') and the City's agents, employees, contractors or representatives to enter upon the Property to inspect the construction of improvements, the performance of work or to allow the City to perform any necessary maintenance or work, all pursuant to that certain Assignment of Funds in Lieu of Bond of even date entered into between the City and the undersigned and incorporated herein by this reference. DATED this day of Y��,� :20 i [Signature Page Follows] https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelld&quickSearchSelection=# 1/5 8/2/2018 Landmark Web Official Records Search Instrun, nt Number: 201805150ODS69 Doccnt:MISC Rec: $78.00 Page-3 of 5 Record Date:5/15/2018 11:54 AM King CO! .. WA ALL-PURPOSE ACKNOWLEDGEMENT State of Nevada County of Clark 00, On May 8, 2018, before meOKrista M. Sunjara, Notary Public, personally appeared, Christopher Aguon"- � rsonally known to me (or proved to me on the basis of satisfactory eviden�:e) to, be the person(s) whose name(s) is/are subscribed to the within instrument aid acknowledged to me that he/she/they executed the same in hisNghheir authorized capacity(ies), and that by his/her/their signature(s) on the,; strument the person(s), or the entity upon behalf of which the persone s) act` -,---executed the instrument. 0- WITNESS my hand and official seal 0 l (e of ary) KHISTA M. SUN1ARA Notary Public, State of Nevada Appointment No.17-3019-1 My Appt. Expires Jun 10, 2021 (Affix seal in the above blank space) https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelId&quickSearchSelection=# 3/5 8/2/2018 Landmark Web Official Records Search lnstrum'•,nt Number: 20180515000669 Dor—lent:MISC Rec: $78.00 Page-5 of 5 Record Datc:5/15/2018 11:54 AM King CoL_ .v, WA I ALL-PURPOSE ACKNOWLEDGEMENT State of Nevada County of Clark R On May 8, 2018, before m aaKgista M. Sunjara, Notary Public, personally appeared, Bruce M. Kahl, personally known to me (or proved to me on the basis of satisfactory evidence) to be the person(s) whose name(s) is/are subscribed to the within instrument Ad acknowledged to me that he/she/they executed the same in lfislher/their authorized capacity(ies), and that by his/her/their signature(s) on the,, instrument the person(s), or the entity upon behalf of which the person(s) acted, executed the instrument. 0- WITNESS my hand and official seal 0 (Sign Not KRISTA M. SUNJARA Notary Publlc, State of Nevada Appointment No. 17-3019.1 ••`� MyAppLExpires Jun 10,2021 (Affix seal in the above blank space) https://recordsearch.kingcounty.gov/LandmarkWeb/search/index?theme=.blue&section=searchCriteriaParcelId&quickSearchSeIection=# 5/5 1 ARC NITECTS 1411 Fourth Avenue Suite 810 June 27, 2018 Mrs. Leila Willouby-Oakes City of Federal Way 33325 8th Avenue S. Federal Way, WA 98003-6325 www.we aver a rct5 . c orrf Seattle Washington 98 10 1 p. 206.262.9622 F. 206.262.9507 RECEIVED JUN 2 8 2018 CITY OF FEDERAL WAY Re: File #17-105848-000-00-CO; 164 SW CAMPUS DR. STE 101 & 102 OOMMUNFTY DEVELOPMENT Listed below is description of the changes made to each sheet to lower the height of the parapets at the perimeter of the building and revising the steel canopies to fabric awnings. Sheet Revision A.2.0: Revised key notes 8 and 9 to reflect moving roof drainage from the interior of the building to the exterior and providing scuppers and downspouts to address roof drainage; steel canopies have been revised to be fabric awnings with steel frames; location and number of columns along grids 1, 2, 7 and grid H has been revised to reflect this change. A.2.1: Removed roof drains and overflows from the roof and replacing them with scuppers and conductor heads to external downspouts at the perimeter of the building. Cricket locations have been revised to reflect the new locations of roof scuppers. A.3.1: Elevations revised to reflect the lowering of parapets at the perimeter of the building, revising the metal canopies to awnings and adding scuppers, collector heads and downspouts at the building exterior walls. The masonry veneer product description has been revised. A.3.2: Elevations revised to reflect the lowering of parapets at the perimeter of the building, revising the metal canopies to awnings and adding scuppers, collector heads and downspouts at the building exterior walls. The masonry veneer product description has been revised. A.4.1: The height of the parapet lowered. The metal canopy in section A has been revised to an awning. A.5.1: The metal canopy in section A has been revised to an awning. A.5.2: The metal canopy in section A&B has been revised to an awning and the parapet height in sections B & C have been lowered. A.5.3: The metal canopy in section A has been revised to an awning. A.6.1: Hardware group #6 has been added to include panic hardware at the inside face of door 210. A.7.1: Details F, G, H and M have been revised to reflect removing the steel canopies and adding scuppers, conductor heads and downspouts. fi 1. S2.0: Revised the number and location of columns along grids 1, 2, 7 and grid H. Added a reference to sheet S4.0 to the foundation notes. Larson &Associates surveyors, engineers & planners 9027 Pacific Avenue, Suite 4 Tacoma, WA 98444-6247 RECEIVED DEC 0 7 2017 OOMMUNF Y DEVELOPAL MEENT -, E- y E $ ,i { i �it- v - aw TECHNICAL INFORMATION REPORT WITH LE ANALYSIS PROPONENT: Covenant Group 2044 California Ave. Corona, CA. 92881 Contact: Julie Margetich Ph: (951) 582-5745 (101,T B 10 DOWNSTREAM s PREPARED BY: Larson & Associates surveyors, engineers & planners 9027 Pacific Avenue, Suite 4 Tacoma, WA 98444-6247 (253) 474-3404 December 6, 2017 PERMIT #: 17-105848-00-CO ADDRESS: PROJECT: New Commercial Building PACIFIC DENTAL BUILDING DATE: 12/7/17 L TA, Bil OF CON. Ma') - T S PROJECTENGINEER'S CERTIFICATION.........................................................................................................1 T.I.R. PROJECTOVERVIEW.............................................................................................................................................. 2 EXISTINGSITE CONDITIONS SUMMARY................................................................................................................. 2 CORE REQUIREMENT #1:DISCHARGE AT THE NATURAL LOCATION.......................................................................... 2 CORE REQUIREMENT #2: CONDITIONS AND REQUIREMENTS SUMMARY.................................................................. 3 COREREQUIREMENT #3: FLOW CONTROL............................................................................................................... 3 CORE REQUIREMENT #4:CONVEYANCE SYSTEM...................................................................................................... 3 CORE REQUIREMENT #5: CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN ..................................... 4-9 CORE REQUIREMENT #6: MAINTENANCE AND OPERATION..................................................................................... 9 CORE REQUIREMEN17#70NANCIAL GUARANTEES AND LIABILITY.......................................................................... 9 COREREQUIREMENT#8: WATER QUALITY................................................................................................................ 9 CORE REQU REMENT#9:FLOW CONTROL BMPS ...................................................................................................9-10 SPECIAL REQUIREMENT # 1: OTHER ADOPTED AREA SPECIFIC REQUIREMENTS.......................................................10 SPECIAL REQUIREMENT #2: FLOOD HAZARD AREA DELINEATION..........................................................................10 SPECIAL REQUIREMENT #3: FLOOD PROTECTION FACILITIES.................................................................................. 10 SPECIAL REQUIREMENT #4: SOURCE CONTROL...................................................................................................... 10 SPECIALREQUIREMENT #5: OIL CONTROL.............................................................................................................10 PROJECTAREA TABLES:.............:...........................................................................................................................11 CONVEYANCE SYSTEM CALCULATIONS.................................................................................................12-16 CONTECH FILTERRA WWHM SIZING CALCULATION.........................................................................17-18 LEVEL 1 AND LEVEL 2 FLOW CONTROL CALCULATIONS.................................................................19-27 OPERATIONAND MAINTENANCE PLAN...................................................................................................28-47 APPENDIX......................................................................................................................................................... Al-A7 DEPARTMENT OF ECOLOGY G.U.L.D. LETTER FOR CONTECH FILTERRA VAULT .................... A2-A9 GEOTECIINICAL ENGINEERING STUDY PREPARED BY KRAZAN......................................................... A10-A44 VICINITYMAP ...................................................... .......... ..................... ................................. I ................... I....... A45 SCSSOILS INFORMATION...................................................................................................................A46-A48 FLOODINSURANCE RATE MAP................................................................................................................. A49 LEVEL 1 DOWNSTREAM ANAYLSIS MAP........................................................................................ A50-A51 PRE -DEVELOPED AND DEVELOPED BASIN MAP................................................................................... A52 �S R 11'�' eT 10-)ffR4 Imo_ ES02IrTAT� �1 I hereby state that this Technical Information Report for Federal Way Commercial of M has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community for professional engineers. I understand that the City of Federal Way does not and will not assume liability for the sufficiency, suitability, or performance of pollution prevention facilities prepared by me. 2 SECTION 1- PROJECT OVERVIEW This technical information report has been prepared to obtain clearing and grading and site development permits for the proposed construction of commercial building which will contain a dentist office and retail space located in a portion of Sec. 19,TWN. 21N, RNG. 4E Willamette Meridian, Federal Way, King County, Washington. The site is inunediately adjacent to SW Campus Drive to the west and 1' Ave. S. to the east. The project site consists of approximately 1.5 acres and is located on parcel number 4159200715. The proposed building will be approximately 5,000 SR The proposed building will be constructed over existing parking lot area that will be removed. There will be minimal cuts/fills (<500CY's) anticipated as this lot is essentially building pad ready with minimal "fill" to construct final pad grade and "drive-thru" isle. Proposed impervious surface associated with building footprint will be tightlined to the Storm Vault for detention, which is downstream of treatment device, prior to being meter released to the existing storm system located at the southwest corner of the property. Roof stormwater is deemed "clean" per Department of Ecology standards and therefore can bypass the Contech Filterra treatment vault. The stormwater from the impervious "drive-thru" isle will be collected via gutter flowline and -muted to and through the proposed Contech Filterra treatment vault and then to i ie St6nn- Vault for detention prior to being meter released to the existing stone system located at the southwest corner of the property. We are proposing grind and overlay of the existing drive isle and parking lot east of the proposed building. Due to this just being a maintenance act, this area will not be subject to quality or quantity control. This project is within the Federal Way Community Planning area and is within the Puget Sound Drainage Basin. EXTSTINC CONDITION SUMMARY The parcel contains existing asphalt parking and drive isle area with perimeter concrete curbing which will be removed to allow for proposed building construction. There are also existing stormwater features and structures located on this parcel which will remain and be protected including an underground stormwater "wet vault", underground oil/water separator vault, "grassed" bioswale and existing retaining wall which are located outside and to the west of the proposed building pad area within an existing storm easement. CORE REQUIREMENT #1; DISCIIARCE AT THE NATURAL LOCATION The stormwater generated by this proposal will be collected in associated catchbasins and discharged in the natural location to existing 30" diameter storm pipe at the southwest portion of the project along SW Campus Drive. The proposed development of this parcel will not alter the existing drainage patterns of the basin nor will it direct stormwater flows offsite across property boundaries to adjacent properties. -L CORE REQUIREMENT #a: OFF -SITE ANALYSIS Please refer to Section 3 of the lst Avenue Basin Pond Technical Information Report prepared by Brown & Caldwell for the downstream analysis portion of this project. A detailed analysis was previously performed qualifying the existing impervious coverage and associated runoff within the offsite drainage system. Furthermore, this proposal will be reducing contributing total impervious area runoff and pollution generating impervious area runoff from the current condition as a parking lot. LEVEL 1 DOWNSTREAM ANALYSIS DISCUSSION: Stormwater discharge from the site will enter the existing SDMH located in southwest corner of the property prior to being discharged through a f200 LF - 30" diam. culvert ruining under SW Campus Drive which then appears to release flows to an unnamed stream. From this point flows appear to be routed within the stream channel south — southeast an additional +-1200 feet to 1st Ave. S. culvert crossing where upon this required qualitative % mile downstream analysis has been terminated. From vision inspection there did not appear to be any capacity issues or maintenance concerns with the existing storm system at our project frontage releasing flows across SW Campus Drive. See the Appendix of this report for a Level 1 Downstream Analysis map for additional information. CORE REQ-[ tREMENT #3: FLOC' CONTROL This project is located within the 1st Avenue South basin regional detention pond basin. The stormwater detention volume for this parcel was included in the previous analysis and design of the existing 1st Avenue South basin pond. See the TIR report previously prepared by Brown & Caldwell dated November 6, 1997 for additional information associated with the analysis and design. After discussion with the City of Federal Way on the understanding of what flow control volume "credit" this project would receive from the previously constructed 1st Ave. S. Basin pond it was determined that our parcel currently meets Level 1 flow control with existing pond consideration. The city then requested that we size a "hypothetical" flow control facility to meet Level 1 flow control requirements and again to size a flow control facility to meet Level 2 flow control meeting the requirements of the 2016 King County Stormwater manual. It was then understood that we would simply be required to provide the deficit in volume between these two levels of analysis. The Level 1 flow control detention facility was designed to meet Level 1 flow control to today's standards matching the existing site conditions 2 and 10 year peak flows. Then we sized a "new" detention facility meeting Level 2 flow control to today's standards applying historic site conditions which match historic durations for 50% of the 2 year through 50 year peak and matches 2 and 10 year peaks. The required volume difference between Level 1 and Level 2 flow control requirements has been determined to be 2,730 CF at detention facility riser crest elevation. We have now proposed an underground detention vault facility achieving this volume of 2,730 CF for this project on the south side of the proposed building within the landscape area to meet flow control facility requirements. The proposed vault will receive tightlined flows from proposed building roof drain connection and runoff associated with the proposed drive thru lane and dumpster pad area. Stormwater will then be metered 3 back out to the existing storm system located in the southwest corner of the property meeting required release rates. CORE REQUIREMENT #4: CONVEYANCE SYSTEM Stormwater runoff generated from this proposal associated with existing and new pollution generating impervious surfaces on this parcel will be collected by associated catchbasins and routed to and through a treatment vault system and storm vault facility via 6"-10" storm pipe discharging flows to the existing storm system at the southwest corner of the property. A 6" roof drain tightline pipe will be provided for connection and routing of roof surface water around the treatment system and to the storm vault. See attached conveyance calculations in the Appendix of this report for pipe size adequacy evaluation. CORE REQUIREMENT #Sa CONSTRUCTION STORMWATER POLLUTION PF.EVENTICNN Stormwater pollution prevention will be maintained during the construction of this site by incorporating standard erosion control methods such as a temporary construction entrance and mirafi siltation fences. The following devices will be used to trap sediment from the cleared areas and prevent it from leaving the site. Mirafi silt fences will be installed along the perimeter to stop any sediment runoff from exiting the project limits. inlet sediment protection will also be installed in all existing and proposed catchbasin locations which have inlet grates to trap sediment and prevent it from entering, the storm system. The following general Washington State Elements shall be upheld at all times during the construction process. 1) Mark Clearing Limits Prior to beginning land disturbing activities, including clearing and grading, all clearing limits shall be clearly marked in the field and trees that are to be preserved shall be clearly marked within the construction area. These shall be marked, both in the field and on the plans, to prevent damage and offsite impacts. 2) Cover Measures This project is currently stabilized with existing impervious surfaces associated with parking lot areas and limits of work will be minimal to construct building pad over existing parking lot. Once asphalt parking lot demolition occurs the building pad will be constructed for building and drive isle and associated landscape areas will be seeded/sodded and/or planted to stabilize exposed pervious areas. 3) Perimeter Protection Prior to demolition activities commencing onsite perimeter silt fence shall be installed around the proposed disturbance area to protect again possible sedimentation offsite. L( 4) Traffic Area Stabilization It is not anticipated that this proposal will require specific stabilization of traffic areas due to limited scope to construct new storm conveyance system, side sewer and water service on the parcel. 5) Sediment Retention Again, prior to clearing/grading and/or demolition activities commencing onsite perimeter silt fence shall be installed around the proposed disturbance area to protect again possible sedimentation offsite and these measures shall be maintained regularly throughout construction. 6) Surface Water Collection Surface water collection will be at existing and proposed catchbasin locations which will be provided with inlet sediment control "socks" to trap sediment and prevent it from entering the storm system. 7) Dewatering Control Due to the size and scope of the project to construct a commercial building at an existing parking lot location we do not anticipate dewatering measures being necessary for this proj ect. 8) Dust Control Again, due to the size and scope of the project to construct a commercial building at an existing parking lot location we do not anticipate dust control being a concern for this project. 9) Flow Control Flow control will be achieved within existing and proposed catchbasin locations which will be provided with inlet sediment control "socks" to trap sediment and prevent it from entering the storm system. 10) Control Pollutants Pollutant Control will be achieved within existing and proposed catchbasin locations which will be provided with inlet sediment control "socks" to trap sediment and prevent it from entering the storm system. There will also be onsite perimeter silt fence installed around the proposed disturbance area to protect again possible sedimentation offsite and these measures shall be maintained regularly throughout construction. 11) Protect Existing and Proposed Flow Control BMPs The existing and proposed storm system onsite will be protected throughout construction with proposed inlet sediment protection devices (ie silt socks) at catchbasin inlet grate locations. The existing storm system on the parcel will be field located prior to construction so it is fully understood where the facilities are located so the contractor can then incorporate necessary protection of said facilities. 5 12) Maintain BMPs All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function in accordance with BMP specifications. All temporary erosion and sediment control BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. 13) Manage the Project • Inspection and Monitoring All BMPs shall be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections and monitoring shall be conducted in accordance with S4. ■ Maintaining an Updated Construction SWPPP The SWPPP shall be maintained, updated, and implemented in accordance with Conditions S3, S4 and S9. Monitoring Requirements The primary monitoring requirements are summarized in Table 3 (below): Table 3. Summary of Manitorin Re uiremtents Size of Soils Disturbance Weekly Weekly Weekly Weekly Site Sampling Sampling w/ pH Inspections w/ Transparency sampling3 Turbidity Tube Meter Sites which disturb less Required uired Not Not Required Not than 1 acre _ _ —Required Re uired Sites which disturb 1 acre or more, but less than 5 Required Sampling Required — either Required acres method q -F Sites which disturb 5 acres Required Required Not s Required or Reuired 1 Additional monitoring requirements may apply for: 1) discharges to 303(d) listed waterbodies and waterbodies with applicable TMDLs for turbidity, fine sediment, high pH, or phosphorus — see Condition SS; and 2) sites required to perform additional monitoring by Ecology order — see Condition GI 3. 2 Soil disturbance is calculated by adding together all areas affected by 19 construction activity. Construction Activity means clearing, grading, excavation, and any other activity which disturbs the surface of the land, including ingress/egress from the site. 3 Beginning October 1, 2006, if construction activity involves significant concrete work or the use of engineered soils, and stormwater from the affected area drains to a stormwater collection system or other surface water, the Pennittee shall conduct pH sampling in accordance with Condition S4.D. 4 Beginning October 1, 2008, sites with one or more acres, but less than 5 acres of soil disturbance, shall conduct turbidity or transparency sampling in accordance with Condition S4.C. 5 Beginning October 1, 2006, sites greater than or equal to 5 acres of soil disturbance shall conduct turbidity sampling using a turbidity meter in accordance with Condition S4.C. A. Site Log Book The Pennittee shall maintain a site log book that contains a record of the implementation of the S WPPP and other permit requirements including the installation and maintenance of BMPs, site inspections, and stormwater monitoring. B. Site Inspections L Site inspections shall include all areas disturbed by construction activities, all BMPs, and all stormwater discharge points. Stormwater shall be visually examined for the presence of suspended sediment turbidity, discoloration, and oil sheen. Inspectors shall evaluate the effectiveness of BMI's and determine if it is necessary to install, maintain, or repair BMPs to improve the quality of stormwater discharges. Based on the results of the inspection, the Pennittee shall correct the problems identified as follows: a. Review the SWPPP for compliance with Condition S9 and make appropriate revisions within 7 days of the inspection; and b. Fully implement and maintain appropriate source control and/or treatinent BMPs as soon as possible, but no later than 10 days of the inspection; and c. Document BMP implementation and maintenance in the site log book. i 2. The site inspections shall be conducted at least once every calendar week and within 24 hours of any discharge from the site. The inspection frequency for temporarily stabilized, inactive sites may be reduced to once every calendar month. 3. Site inspections shall be conducted by a person who is knowledgeable in the principles and practices of erosion and sediment control. The inspector shall have the skills to: a. Assess the site conditions and construction activities that could impact the quality of stormwater, and b. Assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. 4. Beginning October 1, 2006, construction sites one acre or larger that discharge stormwater to surface waters of the state, shall have site inspections conducted by a Certified Erosion and Sediment Control Lead (CESCL). The CESCL shall be identified in the SWPPP and shall be present on -site or on -call at all times. Certification shall be obtained through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (see BMP C 160 in the Manual). 5. The inspector shall summarize the results of each inspection in an inspection report or checklist and be entered into, or attached to, the site log book. At a minimum, each inspection report or checklist shall include: a. Inspection date and time. b. Weather information; general conditions during inspection and approximate amount of precipitation since the last inspection, and within the last 24 hours. c. A summary or list of all BMPs which have been implemented, including observations of all erosion/sediment control structures or practices. d. The following shall be noted: i. locations of BMPs inspected, ii. locations of BMPs that need maintenance, iii. the reason maintenance is needed, iv. locations of BMPs that failed to operate as designed or intended, and v. locations where additional or different BMPs are needed, and the reason(s) why. e. A description of stormwater discharged from the site. The inspector shall note the presence of suspended sediment, turbid water, discoloration, and/or oil sheen, as applicable. f. Any water quality monitoring performed during inspection. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. h. A statement that, in the judgment of the person conducting the site inspection, the site is either in compliance or out of compliance with the terms and conditions of the SWPPP and the permit. If the site inspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, as well as a schedule of implementation. i. Name, title, and signature of the person conducting site inspection; and the following statement: " i certify that this report is true, accurate, and complete, to the best of my knowledge and belief'. CORE REQUIREMENT ##6 MAINTENANCE AND OPERATION See the attached Operation and Maintenance Plan for information regarding this core requirement. CURE REQUIREMENT #7: FINANCIAL GUARANTEES AND LIABILITY This is not applicable to the project at this time. CORE REQUIREMIENT #8: WATER QUALITY Formal water quality treatment has been provided for this project utilizing a Contech Filterra treatment vault which will provide the necessary enhanced "basic" water quality treatment necessary per Department of Ecology and the City of Federal Way requirements. The proposed Contech Filters treatment vault will also provide oil/water separation of stormwater which the City of Federal Way has informed us will be required due to the site's anticipated traffic volume. See the Department of Ecology Letter located in the Appendix of this report describing the General Use Level Designation (GULD) rk issued by the Department of Ecology for the Contech Filterra treatment system to provide enhanced "basic" treatment of stormwater. CORE REQUIREMENT #9: FLOW CONTROL DMPS Regarding flow control BMP implementation for this project it has been deemed infeasible to propose any form of infiltration BMP and/or full dispersion/bioretention due property size, limited onsite pervious surface area for "dispersion" of stormwater and due to onsite soil conditions as specified in the geotechnical infiltration evaluation letter prepared by Krazan located in the Appendix of this report. We have, however, proposed soil amendment of all disturbed pervious surfaces/landscape areas associated with this project meeting 2016 King County stormwater manual requirements and soil amendment criteria. SPECIAL REQUIREMENT #I: OTHER ADOPTED AREA. SPECIFIC REQUIREMENTS There are no additional adopted area specific requirements that we are aware of that must be adhered to for this development proposal. SPECIAL REQUIREMENT #2: FLOOD HAZARD AREA DIALINEA.TION The proposed project does not contain or abut a stream, lake, wetland or closed depression that would require such a study to be performed therefore this does not apply to this project. SPECIAL REQUIREMENT #3: FLOOD PROTECTION FACILITIES This project does not contain or abut a stream therefore this special requirement does not apply to this project. SPECIAL REQUIREMENT #4: SOURCE CONTROL See the attached Operation and Maintenance Plan for information regarding this core requirement. SPECIAL REQUIREMENT 0: OIL CONTROL The proposed Contech Filterra treatment vault will also provide oil/water separation of stormwater which the City of Federal Way has informed us will be required due to the site's anticipated traffic volume. See the Department of Ecology Letter located in the Appendix of this report describing the General Use Level Designation (GULD) issued by the Department of Ecology for the Contech Filterra treatment system to provide oil/water separation. "FEDERAL WAY COMMERCIAL(LOT B " PROJECT AREA TABLES: ONSITE EXISTING CONDITIONS TABLE: TOTAL AREA= 1.157 ACRES PERVIOUS AREA= 0.422 ACRES IMPERVIOUS AREA (EXISTING PARKING LOT) = 0.735 ACRES EX. PARKING LOT & CURBING (TO BE REMOVED) = 0.275 ACRES EX. PARKING LOT & CURBING (TO REMAIN = 0.244 ACRES EX. SIDEWALK (TO BE REMOVED) = 0.019 ACRES EX. SIDEWALK (TO REMAIN) = 0.035 ACRES EX. DRIVE ISLE & CURB (TO REMAIN) = 0.162 ACRES ONSITE PREDEVELOPED AREA TABLE ROUTED TO DETENTION FACILITY TOTAL AREA = 0.294 ACRES PERVIOUS AREA = 0.294 ACRES (MODELED AS TILL FOREST) ONSITE DEVELOPED AREA TABLE ROUTED TO DETENTION FACILITY TOTAL AREA = 0.294 ACRES PERVIOUS AREA = 0.034 ACRES IMPERVIOUS AREA = 0.260 ACRES PROPOSED BUILDING ROOF AREA = 0.118 ACRES PROPOSED DRIVE THRU ISLE & CURB = 0.093 ACRES PROPOSED SIDEWALK = 0.040 ACRES PROPOSED DUMPSTER PAD & CURB = 0.009 ACRES DEVELOPED AREA TRIBUTARY TO "FILTERRA" STORMWATER TREATMENT VAULT TOTAL AREA = 0.142 ACRES IMPERVIOUS AREA = 0.142 ACRES PROPOSED DRIVE THRU ISLE & CURB = 0.093 ACRES PROPOSED CONC. SIDEWALK = 0.040 ACRES PROPOSED DUMPSTER PAD & CURB = 0.009 ACRES. `\ CONVEYANCE SYSTEM CALCULATIONS M CONvF,VA-M t5 Sys,fEN1 L�tc MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.41 Program License Number: 200810005 Project Simulation Performed on: 08/22/2017 3:05 PM Report Generation Date: 08/22/2017 3:06 PM Input File Name: Conveyance Calc..fld Project Name: Federal Way Commercial (Lot B) Analysis Title: Conveyance Calc. Comments: Computational Time Step (Minutes): PRECIPITATION INPUT A Extended Precipitation Time Series Selected Climatic Region Number: 0 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East40 in_5min 10/0111939-10/01/2097 Evaporation Station 961040 Puget East 40 in MAP Evaporation Scale Factor 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default Default HSPF Parameters Used (Not Modified by User) *******w*wwww** ****www*wwwwwwwww*ww** WATERSHED DEFINITION **wwww****ww*ww**www*ww Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.294 0.294 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.294 0.294 --------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---- ----- Subbasin : Subbasin 1 ------Area (Acres) Till Forest 0.294 Subbasin Total 0.294 --------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 -------- Subbasin : Subbasin 1 -------Area (Acres) Till Pasture 0.034 Impervious 0.260 Subbasin Total 0.294 LINK DATA w**a**r�w•rrwwww*xwka*wxa*w� �3 ------------------SCENARIO: PREDEVELOPED Number of Links: 0 aYe*Ak*kRkAJrk*v,y}�Y Fkdiekh LINK DATA ******************************* ----------------------SCENARIO: POSTDEVELOPED Number of Links: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ---------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 0 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perind Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 50.976 Total: 50.976 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 6.027 Total: 6.027 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.323 ac-ft/year, Post Developed: 0.038 ac-ft/year ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 -------------------SCENARIO: POSTDEVELOPED Number of Links: 0 ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Subbasin: Subbasin 1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) 14 2-Year 6.242E-03 2-Year 7.334E-02 5-Year 1.065E-02 5-Year 9.389E-02 10-Year 1.326E-02 10-Year 0.106 25-Year 1.710E-02 25-Year 0.123 50-Year 100-Year 2.059E-02 2.472E-02 50-Year 100-Year 0.137 0.15540----- IbED 16 Wt PIPE CSL'E IOW 54R-r) 200-Year 3.343E-02 200-Year 0.167 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals %S Worksheet Worksheet for Circular Channel Project Description Worksheet 6" Conveyance Flow Element Circular Chann( Method Manning's Forrr Solve For Channel Depth Input Data Mannings Coeffic).010 Slope 0.50 % Diameter 6 In Discharge 0.16 cfs /100 yi, fL W ISEF, FREV100 SWEET, Results Depth 0.19 ft Flow Area 0.1 ft2 Wetted Perime 0.66 ft Top Width 0.48 ft Critical Depth 0.20 ft Percent Full 37.6 % Critical Slope 0.43 % Velocity 2.30 ft/s Velocity Head 0.08 ft Specific Energ, 0.27 ft Froude Numbe 1.09 Maximum Disc 0.55 cfs Discharge Full 0.52 cfs Slope Full 0.05 % Flow Type Supercritical e 1).50' ". 0Ic Project Engineer: Jeff Cederholm federal way commercial lot b conveyance calc.fm2 Larson & Associates FlowMaster v6.1 [614k] 08/22/17 03:38:17 PM © Haestad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1 16 STORM FILTER MANHOLE SIZING CALCULATIONS \-7 Cc>JTEC(4 1RE�►ML�i 0AUL 1 General Sizing Guidelines Based on the Western Washington Hydrology Model (WW Mj E Hydraulic Conductivity: T55jFhosntroreusj I Oil Grease Metals 70.92 in]hr 35.46 in]hr . 24.82 in]hr VANCOUVER Vancouver NNE rain gauge precip factor=1.110 Size Acresireated Acres Treated Acres Treated 4x4 0.349 0.187 0.136 4x6 & 6x4 0.528 0179 0.202 4x8 & 8x4 0.705 '0.372 0.269 6x6 0.794 0.41.9 0.303 6x8 & 8x6 1.063 0.561 0.404 6x10 & 10!6 L332 0.702 0.507 6x12 & 12x6 1.615 . 0.944 0.609 TACOMA 38 in CENTRAL rain gauge _ precipfactor=_3 - note*1901-2059 (yr) Size Acres Treated Acres Treated Acres Treated 4x4 0.421 0.219 0.159 46 & 6x4 0.633 0.325 0.234 48 & 8x4 0,845 0.433 0.31 6x6 0.952 0.487. 0.349 6x8 & 8x6 1.272 0.651 0.465 6x10 & 10x6 1.59A - 0.814 0.582 6x12 & 12x6 1.925 0.981 0.701 EVER ETT Everett rain gage precip factor =1 Site : Acres Treated Acres Treated Acres -Treated 4x4 0.391 0.206 0.151 4x6 & 6x4 :0.589 0.309 0.223 4x8 & 8x4 0.795 0.413 0,297 6x6 0.886 0.463 0.335 6x8 & 8x6 1.185 6.619 0.447 6x10 & 10x6 1.435 0.774 0.558 6x12 & 12x6 1.805 0.933 0.671 SEATTLE Seatac rain gauge precip factor =1 Acres Treated".:: Acres Treated Acres Treated 4x 1 0.384 0.203 0.148 4x6 & 6x4 0.578 0,303 0.219 4x8 & 8x4 0.771 0.403 0.29 6x6 0,871 0.454 0.327 6x8 & 8x6 1.165 0.607 0.437 6x10 & 10x6 1.461 0.76 0.547 6x12 & 12x6 1.787 0.914 0.657 Notes: 1. All treatment areas are based on 100% Impervious contributing drainage area. 2. Filterra size assumes offline configuration and 21" of media. 3. For sizing in other areas, contact your Contech Engineered Solutions Stormwater Design Engineer. 4. General Guidelines Only. Each site is unique and requires sizing per the DOE GULD Approval. 2 ENGINEERED SOLUTIONS 1^ we vu we u.ttix k. Cani's�b.•iti� ., 4V Filfesis � LEVEL 1 AND LEVEL 2 FLOW CONTROL CALCULATIONS 1q j,EV E L 1 � LOQ 60JUTR.O-C FAC.i L1 T %f MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.41 Program License Number: 200810005 Project Simulation Performed on: 08/22/2017 3:02 PM Report Generation Date: 08/22/2017 3:03 PM Input File Name: Detention Vault Sizing (Level 1 Flow Control).fld Project Name: Federal Way Commercial (Lot B) Analysis Title: Treatment Vault Sizing Comments: Computational Time Step (Minutes): PRECIPITATION INPUT .§ Extended Precipitation Time Series Selected Climatic Region Number: 0 Full Period of Record Available used for Routing Precipitation Station : 96004005 Puget East 40 in-5min 10101/1939-10/01/2097 Evaporation Station 961040 Puget East 40 in MAP Evaporation Scale Factor 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.294 0.294 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.294 0.294 PREDEVELOPED Number of Subbasins: 1 --- ------ Subbasin : Subbasin 1 -------Area (Acres) Till Forest 0.294 Subbasin Total 0.294 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 -------- Subbasin: Subbasin 1 ------Area (Acres) Till Pasture 0.034 Impervious 0.260 Subbasin Total 0.294 ************************* LINK ZO ----------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA -------------------SCENARIO: POSTDEVELOPED Number of Links: 1 Link Name: New Structure Lnk1 Link Type: Structure Downstream Link: None Prismatic Pond Option Used Pond Floor Elevation (ft) 100.50 Riser Crest Elevation (ft) : 107.50 Max Pond Elevation (ft) 108.00 Storage Depth (ft) 7.00 Pond Bottom Length (ft) 105.0 Pond Bottom Width (ft) 13.0 Pond Side Slopes (ft/ft) : L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) 1365. Area at Riser Crest El (sq-ft) 1,365. (acres) 0.031 Volume at Riser Crest (cu-ft) 9,555, (ac-ft) 0.219 Area, at Max,Elevation- (sq-ft) 1365. (acres) : 0.031 Vol at Max Elevation (cu-ft) 10,511. (ac-ft) 0.241 Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type Circular Riser Diameter (in) 18.00 Common Length (ft) : 0.000 Riser Crest Elevation : 107.50 ft Hydraulic Structure Geometry Number of Devices: 2 --Device Number Device Type Control Elevation (ft) Diameter (in) Orientation Elbow --- Device Number Device Type Control Elevation (ft) Length (in) Height (in) Orientation Elbow Circular Orifice 100.50 0.25 Horizontal No 2 --- Vertical Rectangular Orifice 104.63 0.25 34.42 Vertical No **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* ----------------------SCENARIO: PREDEVELOPED -2,11 Number of Subbasins: 1 Number of Links: 0 ------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: New Structure Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) 1.05-Year 102.064 1.11-Year 102.269 1.25-Year 102.520 2.00-Year 103.133 3.33-Year 103.668 5-Year 104.148 10-Year 104.888 25-Year 105.110 50-Year 105.140 100-Year 105.202 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perind Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 50.976 Total: 50.976 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 6.027 Link: New Structure Lnk1 0.000 Total: 6.027 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.323 ac-ft/year, Post Developed: 0.038 ac-ft/year ***********Water Quality Facility Data ************* —----------- ------_SCENARIO: PREDEVELOPED Number of Links: 0 ---------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Structure Lnk1 *1FYnY1F***Yfl� Basic Wet Pond Volume (91 % Exceedance): 1162. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 1744. cu-ft Infiltration/Filtration Statistics------------------ Tz Inflow Volume (ac-ft): 119.75 Inflow Volume Including PPT-Evap (ac-ft): 119.75 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0,00% Primary Outflow To Downstream System (ac-ft): 119.72 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Link: New Structure Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) — — Tr (Years) Discharge (cfs) 2-Year --------- 6.242E-03 yYY`v---^- 2-Year 2,706E-03Y--�-----_�-�--�-_�� 5-Year 1.065E-02 5-Year 3,185E-03 10-Year 1.326E-02 10-Year 1.086E-02 25-Year 1.710E-02 25-Year 2.207E-02 50-Year 2.059E-02 50-Year 2.387E-02 100-Year 2.472E-02 100-Year 2.771 E-02 200-Year 3.343E-02 200-Year 2.800E-0Z ** Record too Short to Compute Peak Discharge for These Recurrence Intervals..,_,...- ll3 LEVEL Z F 1,00 C,C),.k3Ti R6 t_ Fro t m( MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.41 Program License Number: 200810005 Project Simulation Performed on: 08/22/2017 3:06 PM Report Generation Date: 08/22/2017 3:05 PM Input File Name: Detention Vault Sizing.fld Project Name: Federal Way Commercial (Lot B) Analysis Title: Treatment Vault Sizing Comments: Computational Time Step (Minutes) PRECIPITATION INPUT :C Extended Precipitation Time Series Selected Climatic Region Number: 0 Full Period of Record Available used for Routing Precipitation Station ; 96004005 Puget East 40 in_5min 10101/1939-10/01/2097 Evaporation Station 961040 Puget East 40 in MAP Evaporation Scale Factor 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) ******* ****** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.294 0.294 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.294 0.294 --------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 -------- Subbasin: Subbasin 1 ------Area (Acres) Till Forest 0.294 Subbasin Total 0.294 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 --------- Subbasin : Subbasin 1 -------Area (Acres) Till Pasture 0.034 Impervious 0.260 Subbasin Total 0,294 *********«*************** LINK DATA Zq --------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA -------------------SCENARIO: POSTDEVELOPED Number of Links: 1 Link Name: New Structure Lnk1 Link Type: Structure Downstream Link: None Prismatic Pond Option Used Pond Floor Elevation (ft) 100.50 Riser Crest Elevation (ft) : 107.50 Max Pond Elevation (ft) 108.00 Storage Depth (ft) 7.00 Pond Bottom Length (ft) 135.0 Pond Bottom Width (ft) 13.0 Pond Side Slopes (ft/ft) L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) 1755. Area at Riser Crest El (sq-ft) : 1,755. (acres) Volume at Riser Crest (cu-ft) : 0.040 12,285. �� — 4J555 Ott. F`r•(l.G'Vs1.: PKoVXVeP)C 2730 MV-r, a��v (ac-ft) 0.282 Z j 821 C". FT. pkckv= Area at Max Elevation (sq-ft) 1755. (acres) : 0.040 Vol at Max Elevation (cu-ft) 13,514. (ac-ft) 0.310 Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Better Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 18.00 Common Length (ft) : 0.000 Riser Crest Elevation : 107.50 ft Hydraulic Structure Geometry Number of Devices: 2 --Device Number Device Type Control Elevation (ft) Diameter (in) Orientation Elbow -- Device Number Device Type Control Elevation (ft) Length (in) Height (in) Orientation Elbow 1 --- Circular Orifice 100.50 0.25 Horizontal No 2 --- Vertical Rectangular Orifice 104.63 0.25 34.42 Vertical No **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* -------------------SCENARIO: PREDEVELOPED ZS Number of Subbasins: 1 Number of Links: 0 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 Link: New Structure Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (fit) ------------------------ 1.05-Year 101.779 1.11-Year 102.033 1.25-Year 102.189 2.00-Year 102.788 3.33-Year 103.222 5-Year 103,568 10-Year 104,387 25-Year 104.852 50-Year 104.919 100-Year 104.971 ***********Groundwater Recharge Summary ************* Recharge is compLited as input to Perind Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 50.976 Total: 50.976 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 6.027 Link: New Structure Lnk1 0.000 Total: 6,027 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years=158) Predeveloped: 0.323 ac-ft/year, Post Developed: 0.038 ac-ftlyear ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 ---------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Structure Lnk1 ********** Basic Wet Pond Volume (91 % Exceedance): 1162. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 1744. cu-ft Infiltration/Filtration Statistics------------------ �i b Inflow Volume (ac-ft): 119.75 Inflow Volume Including PPT-Evap (ac-ft): 119.75 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 119.72 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)/Total Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Link: New Structure Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) 2-Year 6.242E-03 2-Year 2.523E-03 5-Year 1.065E-02 5-Year 2.921 E-03 10-Year 1.326E-02 10-Year 3.288E-03 25-Year 1.710E-02 25-Year 9.375E-03 50-Year 2.059E-02 50-Year 1.220E-02 100-Year 2.472E-02 100-Year 1.465E-02 200-Year 3.343E-02 200-Year 1.824E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than 0%): Maximum Excursion from 50%Q2 to Q2 (Must be Less Than 0%): Maximum Excursion from Q2 to Q50 (Must be less than 10%): Percent Excursion from Q2 to Q50 (Must be less than 50%): MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS -65.3% PASS -65.3% PASS -54.5% PASS 0.0% PASS 2,1 OPERATION AND MAINTENANCE PLAN LARSON & ASSOCIATES, INC. SURVEYORS, ENGINEERS AND PLANNERS 9027 PACIFIC AVENUE, SUITE 4 TACOMA, WA 98444 (253) 474-3404 W OPERATION AND MAINTENANCE PLAN Description of the Federal Way Commercial of S Storm Drainage System. This project is located within the 1" Avenue South basin regional detention pond basin. The stormwater detention volume for this parcel was included in the previous analysis and design of the existing 1st Avenue South basin pond. See the TIR report previously prepared by Brown & Caldwell dated November 6, 1997 for additional information associated with the analysis and design. After discussion with the City of Federal Way on the understanding of what flow control volume "credit" this project would receive from the previously constructed 1" Ave. S. Basin pond it was determined that our parcel currently meets Level 1 flow control'with existing pond consideration. The city then requested that we size a "hypothetical" flow control facility to meet Level 1 flow control requirements and again to size a flow control facility to meet Level 2 flow control meeting the requirements of the 2016 King County Stormwater manual. It was then understood that we would simply be required to provide the deficit in volume between these two levels of analysis. The Level 1 flow control detention facility was designed to meet Level 1 flow control to today's standards matching the existing site conditions 2 and 10 year peak flows. Then we sized a "new" detention facility meeting Level 2 flow control to today's standards applying historic site conditions which match historic durations for 50% of the 2 year through 50 year peak and matches 2 and 10 year peaks. The required volume difference between Level 1 and Level 2 flow control requirements has been detenmined to be 2,730 CF at detention facility riser crest elevation. We have now proposed an underground detention vault facility achieving this volume of 2,730 CF for this project on the south side of the proposed building within the landscape area to meet flow control facility requirements: The proposed vault will receive tightlined flows from proposed building roof drain connection and runoff associated with the proposed drive thru lane and dumpster pad area. Stormwater will then be metered back out to the existing storm system located in the southwest corner of the property meeting required release rates. MAINTENANCE RESPONSiBELITY 1.) Responsible party for maintenance of the storm drainage system: Covenant Group 2044 California Ave. Corona, CA. 92881 Contact: Julie Margetich Ph: (951) 582-5745 The estimated annual cost for maintenance of the storm drainage system as identified in Attachment "A" is $2,000.00 per year. In MAINTENANCE PROGRAM COVER SHEET FOR CITY OF FEDERAL WAY Inspection Period: Number of Sheets Attached: Date Inspected: Name of Inspector: Inspector's Signature: INSTRUCTIONS FOR USE OF MAINTENANCE CHECKLISTS The following pages contain maintenance needs for most of the components that are part of your drainage system, as well as for some components that you may not have. Let the City know if there are any components that are missing from these pages. Ignore the requirements that do not apply to your system. You should plan to complete a checklist for all system components on the following schedule: (1) Monthly from November through April (2) Once in late summer (preferable September) (3) After any major storm (use 1-inch in 24 hours as a guideline), items marked "S" only. Using photocopies of these pages, check off the problems you looked for each time you did an inspection. Add comments on problems found and actions taken. Keep these "checked" sheets in your files, as they will be used to write your annual report. Some items do not need to be looked at every time an inspection is done. Use the suggested frequency at the left of each item as a guideline for your inspection. 3O ATTACHMENT "B" INSTRUCTIONS FOR THE OWNER/S OF "Federal Way Commercial (Lot B)" POLLUTION SOURCE CONTROLS The attached material includes information on pollution source controls. Pollution source controls are actions taken by a person or person representing a business to reduce the amount of pollution reaching surface and ground waters. Pollution source controls also called "best management practices" (BMP's) include: Altering the activity (e.g., substitute not -toxic products or recycle) Enclosing or covering the activity Segregating the activity (e.g. diverting surface water runoff away from an area that is contaminated.) Pollution source controls are needed because of the contamination found in surface water runoff from commercial areas and the effect of this contamination on aquatic life and human health. Research on urban runoff in the Puget Sound area and elsewhere has found oil and grease, nutrients, organic substances, toxic metals, bacteria, viruses, and sediments at unacceptable levels. Effects of contaminate runoff include closure of shellfish harvesting areas and swimming areas, pollution of wells, mortality of young fish and other aquatic organisms, tumors on fish, and impairment of fish reproduction. The Federal Way Commercial (Lot B) project contains impervious surfaces that will collect contaminates from automobiles & garbage. These materials are conveyed to the stonn drainage systems and will enter into the surface water, if not treated properly. Attachment `B" contains a number of BMP's for various uses within the development site. The owner shall give a copy of the BMP's suitable to this or her respective activity. If a certain activity is not contained in Attachment "B", please contact Larson and Associates at 253-474- 3404 for a specific BMP activity type. 3� REQUIRED ACTIONS OF OWNER The following actions shall be taken by all owners to ensure that pollution generated on the Federal Way Conunercial (Lot B) is minimized. 1) Warning signs (e.g. "Dump no waste — drains to Stream") shall be stenciled or embossed adjacent to all catch basin inlets. They shall be repainted once a year or more as necessary. 2) Paved roadways shall be swept twice a year. It is recommended that newer high - velocity vacuum sweeper be used. 3) The storm drainage system shall be maintained per Attachment "A" 4) No activities shall be conducted on the property that is likely to result in a short-term high concentration discharge of pollution to the storm system. Such activities shall include, but are not limited to car washes, vehicle maintenance, and cleaning of equipment and or vehicles, unless the project has been properly permitted for such uses and the BUT's for such uses have been received by the owner. 5) Automobile fluids, chemicals etc. shall be disposed of legally -ancl properly. 6) All garbage shall be contained in appropriate containers. 32 4.3 BMPs TO CONSIDER FOR ALL ACTIVITIES This is a summary of items that each business/homeowner should consider. As stated before, most of these are common sense, housekeeping types of solutions, but if each business/homeowner would take some action on each of these, the improvement in water quality would be substantial. 1. Avoid the activity or reduce its occurrence If you can, avoid the activity or do it less frequently. If there a substitute process or a different material you can use to get the job done? Can you do a larger run of a process at one time, thus reducing the number of times per week or month it needs to be repeated? For instance, raw materials could be delivered close to the time of use instead of being stockpiled and exposed to the weather. Perhaps you could avoid one solvent -washing step altogether. The Department of Ecology can provide pollution prevention assistance. 2. Move the activity indoors Sometimes it is fairly easy to move an activity indoors out of the weather. The benefits of this are twofold; you prevent runoff contamination, and you provide for easier, more controlled cleanup if a spill occurs. An example would be unloading and storing barrels of chemicals inside a garage area instead of doing it outside. Please be aware that moving storage areas indoors may require installation of fire suppression equipment or other building modifications as required by the Uniform Building Code, the Uniform Fire Code, or local ordinances. 3. Use less material Don't buy or use more material than you really need. This not only helps keep potential disposal, storage and pollution problems to a minimum, but will probably save you money, too. 4. Use the least toxic materials available Investigate the use of materials that are less toxic than what you use now. Perhaps a causic-type detergent or a solvent could be replaced with a more environmentally friendly product. Such a change might allow you to discharge process water to the sanitary sewer instead of paying for expensive disposal. Remember that even if you do switch to a biodegradable product, nothing but uncontaminated water is allowed to enter the storm drain system. 5. Create and maintain vegetated areas near activity locations Vegetation of various kinds can help filter pollutants out of stormwater, so it is advisable to route stormwater through vegetated areas located near your activity. For instance, many parking lots contain grassy islands, typically formed in a "hump". By creating those islands as depressions instead of humps, they can be used to treat runoff from the parking lot or roof. Also, don't forget the erosion control benefits of vegetation at your site. 33 6. Locate activities as far as possible from surface drainage paths Activities located as far as possible from known drainage paths, ditches, streams, and drains will be less likely to pollute, since it will take longer for material to reach the drainage feature. This gives you more time to react in the event of a spill, or if it is a "housekeeping" issue may protect the local waters long enougb for you to clean up the area around the activity. Don't forget that groundwater issues are always prominent, no matter where the activity is located so the actions taken on your site on a day-to-day basis are always important, even in dry weather. 7. Keep storm drain systems clean Pollutants can concentrate over time in storm drainage structures such as catch basins, ditches and storm drains. When a large storm event occurs, it can mobilize these pollutants and cant' them to receiving waters. Develop and implement maintenance practices, inspections, and schedules for treatment devices (e.g., detention ponds, oil/water separators, vegetated swales, etc.). Requirements for cleaning catch basins will be discussed later in the specific BMP S.9. S. Reduce, reuse and recycle as much as possible Always look for ways to recycle instead of just disposing. This can save money as well as keep both hazardous and non -hazardous materials out of the landfills. You can learn more about other businesses that have made process changes allowing recycling of chemicals by calling the DCL at 1=80f1- RECYCLE and requesting publication 49245 and 90'22: Anotherunique recycling opportunity for businesses is available through the-�atchmaker", helping one company's waste become another company's asset. For instance, waste peach pits from a cannery become potpourri ingredients to mother's business. Call IMEX at 206-625-623 to list your potentially usable solid or chemical waste in their publication. 9. Be an advocate for stormwater pollution prevention Help friends, partners and business associates find ways to reduce stormwater pollution in their activities. Most people want clean water, and do not pollute intentionally. Share your ideas and the BMPs in this manual to get them thinking about how their everyday activities affect water quality. 10. Report Violators Allowing anyone to pollute our waters is wrong. We all must do our part to protect water, fish, wildlife and our own health, by employing proper BMPs, and reporting those who are causing pollution. 34 STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN II-5.10 BMPS FOR SMALL PARCELS A Small Parcel Stormwater Management Plan must be developed. These in turn may be satisfied by employing a suitable selection from the following list of BMPs. BMP ES.10 PLANNED CLEARING AND GRADING Plan and implementation proper clearing and grading of the site. It is most important only to clear the areas needed, thus keeping exposed areas to a minimum. Phase clearing so that only those areas that are actively being worked are uncovered. Note: Clearing limits should be flagged in the lot or area RA or to initiating clearing. BUT ES.20 EXCAVATING BASEMENT SOIL Located excavated basement soil a reasonable distance behind the curb, such as in the backyard or side yard area. This will increase theslistanoe eroded soil must travel to reach the storm sewer system. Soil piles should be covered until the soil is either used or removed. Piles should be situated so that sediment does not run into the street or adjoining yards. BMP ES.30 BACKFILLING Backfill basement walls as soon as possible and rough grade the lot. This will eliminate large soil mounds which are highly erodible and prepares the lot for temporary cover which will further reduce erosion potential. BMP ES.40 REMOVAL OF EXCESS SOIL Remove excess soil from the site as soon as possible after backfilling. This will eliminate any sediment loss from surplus fill. BMP ES.50 MANAGEMENT OF SOIL BANKS If a lot has a soil bank higher than the curb, a trench or berm should be installed moving the bank several feet behind the curb. This will reduce the occurrence of gully and hill erosion while providing a storage and settling area for stormwater. BMP ES.60 CONSTRUCTION ROAD ACCESS Apply gravel or crushed rock to the driveway area and restrict truck traffic to this one route. Driveway paving can be installed directly over the gravel. This measure will eliminate soil from adhering to tires and stops soil from washing into the street. This measure requires periodic inspection and maintenance including washing, top -dressing with additional stone, reworking and compaction. 55 BMP ES.70 SOIL STABILIZATION Stabilized denuded areas of the site by mulching, seeding, planting, or sodding. BMP ES.80 STREET CLEANING Provide for periodic street cleaning to remove any sediment that may have been tracked out. Sediment should be removed by shoveling or sweeping and carefully removed to a suitable disposal area where it will not be re -eroded. n-5.1 Z References (1) Goldman, Steven J., Erosion and Sediment Control Handbook, McGraw-Hill, 1986. (2) Homer, Richard R., Juno Guedry and Michael H. Kortenhof, Highway Construction Site Erosion and Pollution Control Manual, Washington State Department of Transportation with the United States Department of Transportation Federal Highway Administration, WA-RD 200.2, January, y' 1990. r - (3) Metro, Summary of Preliminary Data Analysis --- BMP Survey of Single Family Residential Construction Sites, January, 1984. (4) Brandy, Nile C., The Nature and Properties of Soils, Eight Edition, MacMillan, 1974. 16 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES 00. 3 - DETENTI0N TANKS AND VAULTS +', Maintenance Defect or Problem Conditions When Maintenance Is Needed Results Expected When Component Maintenance is Performed Site Trash and debris Any trash and debris which exceed 1 cubic foot Trash and debris cleared from site. 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. Noxious weeds Any noxious or nuisance vegetation which may Noxious and nuisance vegetation constitute a hazard to County personnel or the removed according to applicable public. regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches in Grass or groundcover mowed to a height, height no greater than 6 Inches. Tank or Vault Trash and debris Any trash and debris accumulated in vault or No trash or debris in vault. Storage Area tank (includes floatables and non-floatables). Sediment Accumulated sediment depth exceeds 10% of All sediment removed from storage accumulation the diameter of the storage area for% length of storage vault or any point depth exceeds 15% of area. diameter. Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than''/: length of tank. Tank Structure Plugged air vent Any blockage of the vent. Tank or vault freely vents, Tank bent out of Any part of tank/pipe is bent out of shape more Tank repaired or replaced to design. shape than 10.% of its design shape. Gaps between A gap wider than at the joint of any tank i No water or soil entering tank sections, damaged sections or any evidence of soil particles entering through joints or walls. joints or cracks or the tank at a joint or through a wall. tears in wall Damage to wall, Vault Structure Cracks wider than'% -inch, any evidence of soil I Vault is sealed and structurally frame, bottom, and/or entering the structure through cracks or qualified sound. top slab inspection personnel determines that the vault is not structurally sound. Sediment filling 20% or more of the pipe. Inlet/Outlet Pipes Sediment Inletioutlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than 'Y Inch at the joint of the No cracks more than 1/4-inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inlet/outlet pipe. at the joints of the Inlet/outlet pipes. 2016 Surface Water Design Manual — Appendix A 4/24/2016 A-5 3`1 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO. 3 - Maintenance Component Access Manhole ION TANKS AND VAULTS Defect or Problem Conditions When Maintenance is Needed Coverflid not in place Cover/lid is missing or only partially in place. Any open manhole requires immediate maintenance. Locking mechanism Mechanism cannot be opened by one not working maintenance person with proper tools. Bolls Cannot be seated. Self-locking cover/lid does not work. One maintenance person cannot remove Cover/Ild difficult to remove cover/lid after applying 80 Ibs of lift. Ladder rungs unsafe 1 Missing rungs, misalignment, rust, or cracks. Large access Damaged or difficult Large access doors or plates cannot be doors/plate to open opened/removed using normal equipment. Gaps, doesn't cover Large access doors not flat and/or access completely opening not completely covered. Lifting Rings missing, Lifting rings not capable of lifting weight of door rusted or plate. Results Expected When Maintenance is Performed Manhole access covered. Mechanism opens with proper tools. Cover/lid can be removed and reinstalled by one maintenance person. Ladder meets design standards. Allows maintenance person safe access. Replace or repair access door so It can opened as deslgned. Doors close flat; covers access opening completely. Lifting rings sufficient to lift or remove door or plate. 4/24/2016 2016 Surface Water Design Manual — Appendix A A-6 J� APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILMES NO. 4_.CUNTRDL S' TkUCTUK&L 0W RESTRICTOR"' .? s .,_ t Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Structure Trash and debris Trash or debris of more than''/z cubic foot which No Trash or debris blocking or is located immediately In front of the structure potentially blocking entrance to opening or is blocking capacity of the structure structure. by more than 10%. Trash or debris in the structure that exceeds 1/3 the depth from the bottom of basin to invert the No trash or debris in the structure. lowest pipe Into or out of the basin. Deposits of garbage exceeding 1 cubic foot in i No condition present which would volume. attract or support the breeding of Insects or rodents, Sediment Sediment exceeds 60% of the depth from the Sump of structure contains no bottom of the structure to the invert of the lowest sediment. pipe into or out of the structure or the bottom of the FROP-T section or is within 6 inches of the invert of the lowest pipe into or out of the structure or the bottom of the FROP-T section. Damage to frame Comer of frame extends more than % Inch past Frame is even with curb. and/or top slab curb face into the street (If applicable). Top slab has holes larger than 2 square inches Top slab is free of holes and cracks. or cracks wider than Y. inch. Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than % inch of the frame from the top slab. Cracks in walls or Cracks wider than V. inch and longer than 3 feet, Structure is sealed and structurally bottom any evidence of soil particles entering structure sound. through cracks, or maintenance person judges that structure is unsound. No cracks more than 114 inch wide at Cracks wider than'/. inch and longer than 1 foot at the joint of any inlet/outlet pipe or any the joint of inlet/outiet pipe. evidence of soil particles entering structure through cracks. Settlement! Structure has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment. standards. Damaged pipe joints Cracks wider than Y inch at the joint of the No cracks more than'/, -inch wide at inlet/outlet pipes or any evidence of soil entering the joint of inlet/outlet pipes. the structure at the joint of the inlet/outlet pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs Implemented if appropriate. No contaminants present other than a surface oil film. Ladder rungs missing Ladder is unsafe due to missing rungs, Ladder meets design standards and or unsafe misalignment, rust, cracks, or sharp edges. allows maintenance person safe access. FROP-T Section Damage T section is not securely attached to structure T section securely attached to wall wall and outlet pipe structure should support at and outlet pipe. least 1,000 Ibs of up or down pressure. Structure in correct position. Structure Is not in upright position (allow up to 10% from plumb). Connections to outlet pipe are water Connections to outlet pipe are not watertight or show signs of deteriorated grout. tight; structure repaired or replaced and works as designed. Any holes —other than designed holes —in the Structure has no holes other than structure. designed holes. 2016 Surface Water Design Manual — Appendix A 4/24/2016 A-71,(� O ' APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.•4-CI Maintenance Component Cleanout Gate Orifice Plate Overflow Pipe Inlet/Outlet Pipe Metal Grates (If Applicable) NTRQL STRUCTUREIFLOW Rr=STRl TOR° Defect or Problem Condition When Maintenance is Needed Results Expected When Maintenance is Performed Damaged or missing Cleanout gate is missing. Replace cleanout gate. Cleanout gate is not watertight. — Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and down easily and maintenance person. is watertight. Chain/rod leading to gate is missing or damaged. Chain is in place and works as designed. Damaged or missing Control device Is not working mmneflyAue to PI t Obstructions Obstructions Deformed or damaged lip e i Damaged Unsafe grate opening Trash and debris Damaged or missing Trash and debris accumulated In Inlet/outlet pipes (includes floatables and non-floatables). Cracks wider than %cinch at the joint of the Inletloutlet pipes or any evidence of soil entering at the Joints of the inlet/outlet pipes. Grate with opening wider than 7/a Inch. Trash and debris that is blocking more than 20% of grate surface. Grate missing or broken member(s) of the grate. Manhole Cover/Lid Cover/lid not in place Cover/lid is missing or only partially in place. Any open structure requires urgent maintenance. Locking mechanism Mechanism cannot be opened by one Not Working maintenance person with proper tools. Bolts cannot be seated, SeJf-locking cover/lid does not work. Cover/lid difficult to One maintenance person cannot remove Remove cover/lid after applying 80 lbs. of lift. No trash or debris in pipes. No cracks more than''M-inch wide at the joint of the inlettoutlet pipe. Grate opening meets design standards. Grate free of trash and debris. footnote to guidelines for disposal Grate is in place and meets design standards. Cover/Ild protects opening to structure. Mechanism opens with proper tools. Cover/lid can be removed and reinstalled by one maintenance person. 4/24/2016 A-8 2016 Surface Water Design Manual — Appendix A LlD APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.S -- CATCH BASINS AND MANHOLES Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When — Component Maintenance is Performed Structure Sediment Sediment exceeds 60% of the depth from the Sump of catch basin contains no bottom of the catch basin to the invert of the sediment. lowest pipe Into or out of the catch basin or Is within 6 inches of the invert of the lowest pipe Into or out of the catch basin. Trash and debris Trash or debris of more than Y. cubic foot which No Trash or debris blocking or is located immediately in front of the catch basin potentially blocking entrance to opening or is blocking capacity of the catch basin catch basin, by more than 10%. Trash or debris in the catch basin that exceeds No trash or debris in the catch 1/3 the depth from the bottom of basin to invert the lowest pipe into or out of the basin. basin. Dead animals or vegetation that could generate No dead animals or vegetation odors that could cause complaints or dangerous present within catch basin. gases (e.g., methane). No condition present which would Deposits of garbage exceeding 1 cubic foot In volume. attract or support the breeding of insects or rodents. Damage to frame Comer of frame extends more than % inch past Frame is even with curb. and/or top slab curb face into the street (If applicable). Top slab has holes larger than 2 square inches or cracks wider than /4 inch. Top slab is free of holes and cracks. Frame not sitting flush on top slab, i.e., Frame is sitting flush on top slab. separation of more than % inch of the frame from the top slab. Cracks in walls or Cracks wider than Y. inch and longer than 3 feet, Catch basin is sealed and is bottom any evidence of soil particles entering catch structurally sound. basin through cracks, or maintenance person judges that catch basin is unsound. No cracks more than 1/4 inch wide at Cracks wider than '% inch and longer than 1 foot at the joint of any inlet/outlet pipe or any the joint of inlet/outlet pipe. evidence of soil particles entering catch basin through cracks. Settlement! Catch basin has settled more than 1 inch or has Basin replaced or repaired to design misalignment rotated more than 2 inches out of alignment. standards. Cracks wider than at the joint of the inletloutlet pipes or any evidence of soil entering No cracks more than %-inch wide at the joint of Inlet/outlet pipes. Damaged pipe joints the catch basin at the joint of the Inlet/outlet pipes. Contaminants and Any evidence of contaminants or pollution such Materials removed and disposed of pollution as oil, gasoline, concrete slurries or paint. according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated In Inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than'/z-inch at the joint of the inlet/outlet pipes or any evidence of soil entering No cracks more than %-Inch wide at the joint of the Inlet/outlet pipe. at the joints of the Inlet/outlet pipes. 2016 Surface Water Design Manual — Appendix A 4/24/2016 A-9 , ` v APPENDIX A MAINTENANCE RFQU RBMIENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NQ. 5 -CATCH BA$1mts Maintenance Defect or Problem Condition When Maintenance Is Needed Results Expected When Component Maintenance is Performed Metal Grates (Catch Basins) Unsafe grate opening Grate with opening wider than 7/0 inch. Grate opening meets design standards. Trash and debris Trash and debris that Is blocking more than 20% Grate free of trash and debris. of grate surface. footnote to guidelines for disposal Damaged or missing Grate missing or broken member(s) of the grate. Grate Is In place and meets design Any open structure requires urgent standards. maintenance. Cover/lid is missing or only partially in place. Manhole Cover/Lid Cover/lid not in place Cover/lid protects opening to Any open structure requires urgent structure. maintenance. Mechanism cannot be opened by one Mechanism opens with proper tools. Locking mechanism Not Working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. Cover/lid difficult to + One maintenance person cannot remove Coverllid can be removed and Remove ! cover/lid after applying 80 lbs. of lift. reinstalled by one maintenance person. 4/24/2016 2016 Surface Water Design Manual — Appendix A A-10 _11 APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES N6 G -- CIDNVEYANCE PIPES `AN❑ DITCHES Maintenance Defector Problem Conditions When Maintenance is Needed Component Pipes Sediment & debris Accumulated sediment or debris that exceeds accumulation 20% of the diameter of the pipe. Vegetation/roots Vegetation/roots that reduce free movement of water through pipes. Contaminants and Any evidence of contaminants or pollution such pollution as oil, gasoline, concrete slurries or paint. Damage to protective coating or corrosion Damaged Ditches Trash and debris Sediment accumulation Noxious weeds Contaminants and pollution Vegetation Erosion damage to slopes Rock lining out of place or missing (if Applicable) Protective coating Is damaged; rust or corrosion is weakening the structural integrity of any part of pipe. Any dent that decreases the cross section area of pipe by more than 20% or is determined to have weakened structural Integrity of the pipe. 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. Any noxious or nuisance vegetatlon which may constitule a hazard to County personnel or the public. Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Vegetation that reduces free movement of water through ditches. Any erosion observed on a ditch slope. Results Expected When u Maintenance is Performed Water flows freely through pipes. Water flows freely through pipes. Materials removed and disposed of according to applicable regulations. Source control BMPs Implemented if appropriate. No contaminants present other than a surface oil film. 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. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Water flows freely through ditches Slopes are not eroding. One layer or less of rock exists above native soil Replace rocks to design standards. area 5 square feet or more, any exposed native soil. 2016 Surface Water Design Manual — Appendix A 4/24/2016 A-11 "3 APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.11 - GROUNDS (LANDSCAPING) Maintenance Component Defect or Problem Conditions When Maintenance is Needed Results Expected When Maintenance Is Performed Site Trash or litter Any trash and debris which exceed 1 cubic foot Trash and debrls cleared from site. 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. Noxious weeds Any noxious or nuisance vegetation which may constitute a hazard to County personnel or the public. Noxious and nuisance vegetation removed according to applicable regulations. No danger of noxious vegetation where County personnel or the public might normally be. Contaminants and pollution Any evidence of contaminants or pollution such as oil, gasoline, concrete slurries or paint. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Grass/groundcover Grass or groundcover exceeds 18 inches In Grass or groundcover mowed to a height. height no greater than 6 inches. Trees and Shrubs Hazard Any tree or limb of a tree identified as having a potential to fall and cause property damage or No hazard trees in facility. threaten human life. A hazard tree Identified by a qualified arborist must be removed as soon as possible. Damaged 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 and shrubs with less than 5% of total foliage with split or broken limbs. Trees or shrubs that have been blown down or knocked over. No blown down vegetation or knocked over vegetation. Trees or shrubs free of Injury. Trees or shrubs which are not adequately supported or are leaning over, causing exposure of the roots. Tree or shrub In place and adequately supported; dead or diseased trees removed. 4/24/2016 A-16 2016 Surface Water Design Manual — Appendix A _ U\ APPENDIX A MAINTENANCE REQUIREMENTS FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO, 21 - STORVIFILTER (CARTRIDGE TYPE) Maintenance Component Facility Site Vault Treatment Area Defect or Problem I Condition When Maintenance is Needed Documentation Update facility inspection record after each inspection. Provide certification of replaced filter media. Trash and debris Any trash or debris which impairs the function of the facility. Contaminants and + Any evidence of contaminants or pollution such pollution I as oils, gasoline, concrete slurries or paint. Life cycle Sediment on vault floor System has not been inspected for three years. Greater than 2 inches of sediment. Results Expected When Maintenance is Performed Maintenance records are up to date. Filter media is certified to meet Stormfilter® specifications. Trash and debris removed from J facility. Materials removed and disposed of according to applicable regulations. Source control BMPs implemented if appropriate. No contaminants present other than a surface oil film. Facillty Is re -inspected and any needed maintenance performed. Vault is free of sediment. Sediment on top of Greater than % Inch of sediment. Vault is free of sediment. cartridges 1 Multiple scum lines Thick or multiple scum lines above top of Cause of plugging corrected, above top of cartridges. Probably due to plugged canisters or canisters replaced if necessary. cartridges underdrain manifold. _ Vault Structure Damage to wall, Cracks wider than %-Inch and any evidence of Vault replaced or repaired to design Frame, Bottom, soil particles entering the structure through the specifications. and/or Top Slab cracks, or qualified inspection personnel determines the vault is not structurally sound. Baffles damaged Baffles corroding, cracking warping, and/or Repair or replace baffles to showing signs of failure as determined by specification. maintenancelinspection person. 9 inches or greater of static water in the vault for Filter Media Standing water in No standing water in vault 24 hours vault more than 24 hours following a rain event and/or after a rain event. overflow occurs frequently. Probably due to plugged filter media, underdrain or outlet pipe. Short circuiting Flows do not property enter filter cartridges. Flows go through filter media. Underdrains and Sediment/debris Underdrains or clean -outs partially plugged or Underdrains and clean -outs free of Clean -Outs filled with sediment and/or debris. sediment and debris. Inlet/Outlet Pipe Sediment Sediment filling 20% or more of the pipe. Inlet/outlet pipes clear of sediment. accumulation Trash and debris Trash and debris accumulated in inlet/outlet No trash or debris in pipes. pipes (includes floatables and non-floatables). Damaged Cracks wider than ''Y inch at the joint of the No cracks more than 1/4-inch wide at inlet/outlet pipes or any evidence of soil entering the joint of the inletloutlet pipe. at the joints of the inlet/outlet pipes. Access Manhole Cover/lid not in place Cover/lid is missing or only partially in place. Manhole access covered. Any open manhole requires Immediate maintenance. Locking mechanism Mechanism cannot be opened by one Mechanism opens with proper tools. not working maintenance person with proper tools. Bolts cannot be seated. Self-locking cover/lid does not work. One maintenance person cannot remove ` Cover/lid can be removed and Cover/lid difficult to remove cover/lid after applying 80 Ibs of lift. reinstalled by one maintenance person. 4/24/2016 A-30 IA5 2016 Surface Water Design Manual — Appendix A APPENDIX A MAINTENANCE REQUIREMENTS FOR FLOW CONTROL, CONVEYANCE, AND WQ FACILITIES NO.'21 STORMFIL:TER.(CARTRIDGE�TYPE) ;3 Maintenance Defect or Problem Condition When Maintenance is Needed Results Expected When Component Maintenance is Performed Ladder rungs unsafe Missing rungs, misalignment, rust, or cracks. Ladder meets design standards. Allows maintenance person safe access. Damaged or difficult Large access doors or plates cannot be Large access Replace or repair access door so it doors/plate to open opened/removed using normal equipment. can opened as designed. Gaps, doesn't cover Large access doors not flat and/or access Doors close flat and cover access completely opening not completely covered. opening completely. Lifting rings not capable of lifting weight of door Lifting Rings missing, Lifting rings sufficient to lift or rusted or plate. remove door or plate. Inspect Stormfllter facility for any Inspection Frequency Maintenance conditions are site -specific, depending on pollutant loading. maintenance deficiencies; maintain FIRST YEAR POST CONSTRUCTION: Monthly or replace as required per established site -specific schedule during wet season, every other month during dry and manufacturer's requirements. season FOLLOWING FIRST YEAR: Continue monthly until site -specific frequency Is established, then follow that schedule AT A MINIMUM, FOLLOWING FIRST YEAR: Annually (or quarterly if used as primary treatment) and following significant stones. 2016 Surface Water Design Manual — Appendix A 4/24/2016 A-31 '.'t 6 and Lx T p G N H.TS Po Lkw Table un / L.r+vlS LMnouee u 122.W I N13 34-11 curve TWO Orr. twgm Rkin Utz IN= 3moo 3541w, IC3 2M77 442-M J772'w 226.D4 4Do.00 sl" ]DATA &W FARM 40CE"O 9Te AMR= N/A AQIFAW tic 20"m ew nropaw (w CONAW" Q=FAFW TMa zvmr aq- Cm k ReLtAI FOD1PWr AWA $T27 SF. 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A?0-061!D RPMA AM 'NOr lair PROPOIm WARN 100 0 PR IPosm roe fr MIXT4 PpppOSpp INCAMW WTEW ® meoP— POIQL TAAIl ORLF!J1 _.sr111Aer... wil� its 12-6-17 APPENDIX LARSON & ASSOCIATES, INC. SURVEYORS, ENGINEERS AND PLANNERS 9027 PACIFIC AVENUE, SUITE 4 TACOMA, OVA 98444 (253) 474-3404 N1 lh.,� WN11100 WASHIN 6 TON S T A T I O E P A M 6 N T . , C 0 L 0 G Y November 2016 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), ENHANCED, PHOSPHORUS & OIL TREATMENT For Americast Filterra® C-Ba �wdon A illef-i C',1 St 18. S Ll 11111 iSSiOl Is. i tic I ud i ng the TinaiTeclu-kal Eva] ual ion Reports, dated Alarch 27,2014 and December' 2009, and additional iiforniatlon provided to &olog)r d,flcd 1,06 tol)eT 0. 2009, FQ()I ogy here -by IsSu'6s the f"0.11 OW.111�, Use I t;,.v61'- designations: A Genera I Ilse: I -eve] 1) os igna vi on 14r l3a5I e, F nhm ced.-Pliosphol-us. and ()i I ]'roat menil at 1J �-iydraullc collductivily ` OTI/fil.) for tltie in Western Sizing rh f iltratl on Rate (in/hr) , for uso in 6ing asic L. 0 5-:46 rmha-iiccd 24,82 Aleulated Msbd on:'hsted infiltraftoji'rate,and a hydraulic ga(tieut of I'Al bi6 ,b6 � .4hj fbi- oil Spli1v-G,Jl1L[.(;lT- ol%41s. -3,.- f`,cology approves thL: Fill.CITLI' Llllals 1,01 truatruent.at the hydraulic luadinti rates listed abovo, to kilie've flic n1axiJ1111111 qJ1911ty do,. flow rate.. CWulaU,, the wafer quality design I L imgt Cot, treatment insta I led upsi rcam I'd etent; ci 1 oi retention, (he water 0 N -iiiinitte i10", rate I and fil.Lel, di" on rate is the peak 15 using s, $, !:I the 111 od U-1 C in the' latest : V the Wesleril lVashington Hydrology Model or other Ecology-apprOved cpiitillllolls runoff niodel. jjle 1111LACI 111LIS11 ilkllCilte thU unit :is capable cri.ploc sling 'I pericent ofthe iliffileill kullofMe, j� Hastpni Waghingloii: FortfeatTIICTII installed upstrearn of de'tentioll or rebenliou-the Waldr Lqualify desig tic 9 Pow rat.Pk I peak T5 -nuipute flo"A' rate as.- Cale u lated using orle, 0 1'. the three how fate based niethods d� . krihud in Chai?ior.12_5'bfthe Stommater N/lamigenTelit Manual. ... Al • Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 4. This General Use Level Designation has no expiration date but Ecology may revoke or amend the designation, and is subject to the conditions specified below. Ecology's Conditions of U%(-` 'Filterra° units shall comply with these conditions shall comply with the following conditions: 1. Design, assemble, install, operate, and maintain the 1~ilterrao units in accordance with applicable Americast Filterra' manuals, document, and the Ecology Decision. 2. Each site plan must undergo Americast Filterra* review before Ecology can approve the unit for site installation. This will ensure that site grading and slope are appropriate for use of a Filterra" unit. i3. Filterra"' media shall conform to the specifications submitted to and approved by Ecology. A. Maintenance includes removing trash, degraded mulch, and accumulated debris from the filter surface and replacing the mulch layer. Use inspections to determine the site -specific maintenance schedules and requirements. Follow maintenance procedures given in the most recent version of the Filterrae Operation and Maintenance Manual. -5. Maintenance: The required maintenance interval for stormwater treatment devices is often dependent upon the degree of pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a "one size fits all'' maintenance cycle for a particular modellsize of manufactured filter treatment device. • Filterra® designs their systems for a target maintenance interval of 6 months. Maintenance includes removing accumulated sediment and trash from the surface area of the media, removing the mulch above the media, replacing the mulch, providing plant health evaluation, and pruning the plant if deemed necessary. ■ Conduct maintenance following manufacturer's guidelines. 6. Filterrac. units come in standard sizes. 7. The minimum size filter surface -area for use in western Washington is determined by using the sand filter module in the latest version of WWHM or other Ecology approved continuous runoff model for western Washington. Model inputs include ;a) Filter media depth. 1.8 feet b) Effective Ponding Depth: 0.75 feet (This is equivalent to the 6-inch clear zone between the top of the mulch and the bottom of the slab plus 3-inches of mulch.) c) Side slopes: Vertical :d) Riser height: 0.70 feet e) Filter Hydraulic Conductivity: Use the Hydraulic Conductivity as listed in the table above (use the lowest applicable hydraulic conductivity depending on the level of treatment required) under Ecology's Decision, above. 2 A-� rilniirn r tilter`s ii'I'aec-area fm Liw IIi eastern �h�ilti�Ifll�l:elI3 f5 (lelt l'1131nEd 11� USj;Ig' the design water quality 11nv ra#e. (as dciennined ill it6m 3, -,ibix ve) and the Infiltration Ralb f-T-Om the table above.'(=: t).le Iowest awl iC4k.ie III ftltra iiili Rate cicpendillg oil the level of.. tietltrnurlt.reslttixetll. Cals;tilate ti)e retjUired area by dividing.tf e water qualit" design ROw• rite: (ru-tlfSec) t7y; the,intiltration Rate .(converted ta. ft See} to obtain req-tared Wface.areEt f,` l fl}_• . o l- the IA l teil a ti.n it. Dist Ial—geti trom the Fifterr-a" tlnits shall hot C,att e car cnrltrilxitC. to water clu tlzty stetld�lr'as vjola ions:in recejvingy t3'atct' . �A lroved Alternate Configurations iTilterru` lntern aI Bypass - Pilre (F..l'.113-P) The Filtetrg(R) Internal Bypass.- 4' & allows f6y piped -in flora' from area draills. grated tiflets, ti'eriuh draim., a-lid/o' roof.&ADLs. Demgn. capt tire tIows and peak Rows enter: ilie structure thr.oligh an. interilal Siottod pile. Filter ra" inverted the -dotted pipe tO ifflo w clesign:ilaws:tp: drop lirrnl th toa.scr'ies �,i`spla5ll plate,, th�ii tlim disparsetllc design1_lows over t1jN top Surface sal tllc: l ilrcrra" .planter ales: Higher flt�r�'s cntititlu� tta b)l)ass the slotted -pipe Ind COnviy. OUt 1.11e StfI1d:iI17C- �2. Tr, selut a V'1 B-p unit, the;d _j, must detetn�irie tiic size, of the. statxitu'ci ttriit using the 'r' siciilg gtlidauce..desc.ribed ve:140 Ai ilte r aC, lister I a I Bv- iisS--^('urh n'1B-' 1 I'lie Filtct1it0 11ternal'13ypass -C-Arb model (1-T11.34') i�tcnrporate.s acurb Inlet. h1c�liitratiUn .. fit�ltl.11nl Chamber, aii�t irlienlal'lli;T1� Ilctt�' lr.y:pass in [ire sirllc. stntttne..PiltGrraCt desi�meLi .the FT1134 mode). for 6sejig a ` � >I' Surllp' corlttition and .will accept flo%as title. both directions along a gut[ti lijie. Au its#ei'tral ilel111e.tray ivoir cc+r poilem dlwuls tfeatntent flnV;°s;'. ritctlElg tlie. tftlli gllrotif;h the curb inlet to the bii�l'ilr'21" r)it reatment chamber. l±lou-s m excess oi: lt'ic water tlitali:ty ireatlllerli llm� rise above. #ncltlil7e trtii weir rincl.clis(iraroe r llt•mtffh a sfandl ipe t7rit.i.4G; p1•e)vidMg k:rypass.Of' utttrcatCd peak flows. America to ttul'acttlres the i TT13-C� mndel in a variety of sizes and c:�.on#igiiratitziis slid: You I use.tiie utrit [ill I u)ntiniiou5 adu wlluFr a.sirtgle Structure. prw,ddillg btiili treatment.and }ii.l;ls flow b3l-)ass is pieferred, The FI'M-C. nxlclel cal a]sO ltic otporal C a scparate}u.iietiotl-boy t:htinllaer, tci allow larger-diarneter discharge:pjpe connec.t.iotl', to the structure;. 7, Toseiect.a 1 'TI13_C unit - rile c1i signer must dete3suiite tb&E,size of -the standard unit using the Sirltlg gmdailce described ahov+ . l++iltcrr�i` Sllallu�y I 1. ity lnr.tesigli gei,engitlecsatrdcGlnin The Fllicrra`� ill tlwpnbi7xji situations where thclC is Iimit�ri c�el7tlr alici vaiious elevation Gt-illstraiztts tQ apl,),iyiil a staitclard iiteri`a onf Fu.r'ation: ngiiieers ball design Ns systeltl:LTp to six inches S1 alimwer l,. t11Fu11 any of t. - lrevi[3us I ilierra:. t �c)rifiguratuolls kited above. a 2. lacolo y. reqi Tres. ill t}ze Fill rta 'r a�loW prof id coiitaet time:vy>ii��Ie�lt 1c� that. nr thL staridrtrEl Uilit. 1 hit; ntcslns that zit sinailel del)th ()f incc] ia. th `sttrlacc �lle,a tiaust increase. 3., To suit ci a Filterra°L' Shallow 5,usteru >tnit;.ille dc.;ignez' rl>tltit first itlentify..s.h.e situ s�f'the 'Vil SUITid rd UII11:U:l3li, tile.mdelil Icy Otlidar1CC-,' esei-ilbed abm,e:.." i4. Om'e 011 CSIRNiSh the size.of thestwidard 1' 1ltLi-}' Y Lllltt usilk-P, the siZi- 9 tMlllllyiif':.tlUsci'shC Qu . use information from the, it0110Wi112 table, to se.lcct the al,lx'ol�riate size.17iIlerra Shallow Svstelli utm; li;lfic+r 1!nit Lass. C.nll<luced, and Oil Ti'tUneoiiZizlg ;st%ixlarcl Depth 4l4 -----------40.tit fix ,....^_ .q�iral�xii Shallo�v.De 4x.6 ot• Gx 4 _-------- YxR or Sxh 6x 1-0 6r 10x6 _ r....� fix 1.2 nr 120 to _...._ _ t11 . Stull xA- -are iess'than the slandat�d gut <. t =�� a" 'fl � e }: Applicant: Applicant's Address: Application Documents: Filterra® Bioretention Systems, division of Contech Engineered Solutions, LLC. 11815 NE Glenn Widing Drive Portland, OR 97220 • State of Washington Department of Ecology Application for Conditional Use Designation, Americast (September 2006) ■ Quality Assurance Project Plan FilterraO Bioretention Filtration System Performance Monitoring, Americast (April 2008) • Quality Assurance Project Plan Addendum Filterra* Bioretention Filtration System Performance Monitoring, Americast (June 2008) • Draft Technical Evaluation Report FilterraO Bioretention Filtration System Performance Monitoring, Americast (August 2009) • Final Technical Evaluation Report Filterrao Bioretention Filtration System Performance Monitoring, Americast (December 2009) • Technical Evaluation Report Appendices Filterra® Bioretention Filtration System Performance Monitoring, Americast, August 2009 ■ Memorandum to Department of Ecology Dated October 9, 2009 from Americast, Inc. and Herrera Environmental Consultants 4 pry ■ Quality Assurance Project Plan FilterraP Bioretention System Phosphorus treatment and Supplemental Basic and Enhanced Treatment Performance Monitoring, Americast (November 2011) ■ Filters® letter August 24, 2012 regarding sizing for the Filterra® Shallow System. ■ University of Virginia Engineering Department Memo by Joanna Crowe Curran, Ph. D dated March 16, 2013 concerning capacity analysis of Filterra® internal weir inlet tray. • Terraphase Engineering letter to Jodi Mills, P.E. dated April 2, 2013 regarding Terraflurne Hydraulic Test, FilterraO Bioretention System and attachments. • Technical Evaluation Report, Filterra" System Phosphorus Treatment and Supplemental Basic Treatment Performance Monitoring. March 27`h, 2014. Applicant's Use Level Request: General Level Use Designation for Basic, Enhanced, Phosphorus, and Oil Treatment. Applicant's Performance Claims: Field-testing and laboratory testing show that the Filterrao unit is promising as a stormwater treatment best management practice and can meet Ecology's performance goals for basic, enhanced, phosphorus, and oil treatment. Findings of Fact: Field Testin 2013 1. Filtmra* completed field-testing of a 6.5 ft x 4 ft. unit at one site in Bellingham, Washington. Continuous flow and rainfall data collected from January 1, 2013 through July 23, 2013 indicated that 59 storm events occurred. The monitoring obtained water quality data from 22 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data. 2. The system treated 98.9 percent of the total 8-month runoff volume during the testing period. Consequently, the system achieved the goal of treating 91 percent of the volume from the site. Stormwater runoff bypassed during four of the 59 storm events. 3. Of the 22 sampled events, 18 qualified for TSS analysis (influent TSS concentrations ranged from 25 to 138 mglL). The data were segregated into sample pairs with influent concentration greater than and less than 100 mg/L. The UCL95 mean effluent concentration for the data with influent less than 100 mg/L was 5.2 rnglL, below the 20- mg/L threshold. Although the TAPE guidelines do not require an evaluation of TS S removal efficiency for influent concentrations below 100 mg/L, the mean TSS removal for these samples was 90.1 percent. Average removal of influent TSS concentrations greater than 100 mg/L (three events) was 85 percent. In addition, the system consistently exhibited TSS removal greater than 80 percent at flow rates at a 100 inches per hour [in/hr] infiltration rate and was observed at 150 in/hr. ►• 4. Ten of the 22 sampled events qualified for TP analysis. Americast augmented the dataset using two sample pairs from previous monitoring at the site. Influent TP concentrations ranged from 0.11 to 0.52 mglL. The mean TP removal for these twelve events was 72.6 percent. The LCL95 mean percent removal was 66.0, well above the TAPE requirement of 50 percent. Treatment above 50 percent was evident at 100 in/hr infiltration rate and as high as 150 in/hr. Consequently, the Filterra® test system met the TAPE Phosphorus Treatment goal at 100 in/hr. Influent ortho-P concentrations ranged from 0.005 to 0.012 mg/L; effluent ortho-P concentrations ranged from 0.005 to 0.013 mg/L. The reporting limit/resolution for the ortho-P test method is 0.01 mg/L, therefore the influent and effluent ortho-P concentrations were both at and near non -detect concentrations. Field Testing 2008-2009 1. Filterrao completed field-testing at two sites at the Port of Tacoma. Continuous flow and rainfall data collected during the 2008-2009 monitoring period indicated that 89 storm events occurred. The monitoring obtained water quality data from 27 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data. 2. During the testing at the Port of Tacoma, 98.96 to 99.89 percent of the annual influent runoff volume passed through the POT1 and POT2 test systems respectively. Stormwater runoff bypassed the POTI test system during nine storm events and bypassed the POT2 test system during one storm event. Bypass volumes ranged from 0.13% to 15.3% of the influent storm volume. Both test systems achieved the 91 percent water quality treatment - goal over the 1-year monitoring period. 3. Consultants observed infiltration rates as high as 133 in/hr during the various storms. Filterra® did not provide any paired data that identified percent removal of TSS, metals, oil, or phosphorus at an instantaneous observed flow rate. 4. The maximum storm average hydraulic loading rate associated with water quality data is <40 in/hr, with the majority of flow rates < 25 in/hr. The average instantaneous hydraulic loading rate ranged from 8.6 to 53 inches per hour. 5. The field data showed a removal rate greater than 80% for TSS with an influent concentration greater than 20 mg/1 at an average instantaneous hydraulic loading rate up to 53 in/hr (average influent concentration of 28.8 mg/l, average effluent concentration of 4.3 mg/1). 6. The field data showed a removal rate generally greater than 54% for dissolved zinc at an average instantaneous hydraulic loading rate up to 60 in/hr and an average influent concentration of 0.266 mg/1(average effluent concentration of 0.115 mg/1). 7. The field data showed a removal rate generally greater than 40% for dissolved copper at an average instantaneous hydraulic loading rate up to 35 in/hr and an average influent concentration of 0.0070 mgll (average effluent concentration of 0.0036 mg/1). 8. The field data showed an average removal rate of 93% for total petroleum hydrocarbon (TPH) at an average instantaneous hydraulic loading rate up to 53 in/hr and an average influent concentration of 52 mg/1 (average effluent concentration of 2.3 mg/1). The data 6 Arl also shows achievement of less than 15 mg/l TPH for grab samples. Filterrao provided limited visible sheen data due to access limitations at the outlet monitoring location. The field data showed low percentage removals of total phosphorus at all storm flows at an average influent concentration of 0.189 mg/1(average effluent concentration of 0.171 mgll). We may relate the relatively poor treatment performance of the Filterrao system at this location to influent characteristics for total phosphorus that are unique to the Port of Tacoma site. It appears that the Filterrao system will not meet the 50 percent removal performance goal when you expect the majority of phosphorus in the runoff to be in the dissolved form. Laboratory Testin 1. Filterrao performed laboratory testing on a scaled down version of the Filterra® unit. The lab data showed an average removal from 83-91% for TSS with influents ranging from 21 to 320 mg/L, 82-84% for total copper with influents ranging from 0.94 to 2.3 mg/L, and 50-61% for orthophosphate with influents ranging from 2.46 to 14.37 mg/L. 2. Filterrao conducted permeability tests on the soil media. 3. Lab scale testing using Sil-Co-Sil 106 showed percent removals ranging from 70.1% to 95.5% with a median percent removal of 90.7%, for influent concentrations ranging from 8.3 to 260 mg/L. Filterral ran these laboratory tests at an infiltration rate of 50 in/hr. 4. Supplemental lab testing conducted in September 2009 using Sil-Co-Sil 106 showed an average percent removal of 90.6%. These laboratory tests were run at infiltration rates ranging from 25 to 150 irdlir for influent concentrations ranging from 41.6 to 252.5 mg/1. Regression analysis results indicate that the FilterraO system's TSS removal performance is independent of influent concentration in the concentration rage evaluated at hydraulic loading rates of up to 150 in/hr. Contact Information: Applicant: Jeremiah Lehman Contech Engineered Solutions, LLC. 11815 Glenn Widing Dr Portland, OR 97220 (503) 258-3136 jlehman _.conteches.cozn Applicant's Website: h=:/Iwww.conteches.com Ecology web link: httn://Www.ecYwa.govlprog!-&Iwg/stonnwaterinewtech/index.html Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 douglas. howi ,�ecv.wa.g❑V Date Revision December 2009 GULD for Basic, Enhanced, and Oil granted, CULD for Phosphorus September 2011 Extended CULD for Phosphorus Treatment September 2012 Revised design storm discussion, added Shallow System. January 2013 Revised format to match Ecology standards, changed Filterra contact information February 2013 Added FTIB-P system March 2013 Added FTIB-C system April 2013 Modified requirements for identifying appropriate size of unit Modified description of FTIB-C alternate configuration June 2013 March 2014 GULD awarded for Phosphorus Treatment. GULD updated for a higher flow -rate for Basic Treatment. June 2014 Revised sizing calculation methods March 2015 Revised Contact Information June 2015 CULD for Basic and Enhanced at 100 in/hr infiltration rate November 2015 Removed information on CULD (created separate CULD document for 100 in/hr infiltration rate) Revised text regarding Hydraulic conductivity value June 2016 November 2016 Revised Contech Contact information DRAFT GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED NEW DENTAL OFFICE PARCEL NO.415920-0715 SW CAMPUS DRIVE AND 1sT AVENUE SOUTH FEDERAL WAY, WASHINGTON 98023 Project No. 062-16008 JANUARY 20, 2017 Prepared for: COVENANT GROUP ATIN: Ms. JULIE A. MARGEnCH 2044 CALIFORNIA AVENUE CORONA, CA 92881 Prepared by: KRAzAN & ASSOCIATES, INC. GEOTECHNICAL ENGINEERING DIVISION 4303 — 198h St SW Lynnwood, Washington 98036 (425) 485-5519 4dKrazan& ASSOCIATES,INC. GEOTECHNICAL ENGINEERING ■ ENVIRONMENTAL ENGINEERING CONSTRUCTION TESTING & INSPECTION January 20, 2017 DRAFT Krazan File Number 062-16008 Covenant Group 2044 California Avenue Corona, CA 92881 Attention: Ms. Julie A. Margetich Email: MargetichJ acificdentalservic_es.com Tel: (951) 582-5745 Reference: Geotechnical Engineering Investigation Proposed New Dental Office Parcel No. 415920-0715 SW Campus Drive & 181 Avenue South Federal Way, WA Greetings, In accordance with your request, we have completed a Geotechnical Engineering Investigation for the referenced site. The results of our investigation are presented in the attached report. If you have any questions, or if we can be of further assistance, please do not hesitate to contact our office. Respectfully submitted, KRAZAN & ASSOCIATES, INC. Michael D. Rundquist, P.E. Senior Project Manager JGL/MDR Offices Serving The Western United States 4303 —198'h St SW • Lynnwood, Washington 98036 • (425) 485-5519 • Fax: (425) 485-6837 NX k „,—I<razan & ASSOCIATES,INC. GEOTECHNICAL ENGINEERING • ENVIRONMENTAL ENGINEERING CONSTRUCTION TESTING & INSPECTION January 20, 2017 KA Project No. 062-16008 DRAFT GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED DENTAL OFFICE PARCEL NO.415920-0715 SW CAMPUS WAY & 1sT AVENUE SOUTH FEDERAL WAY, WASHINGTON 98023 INTRODUCTION This report presents the results of our Geotechnical Engineering Investigation for the proposed dental office project located near the intersection of SW Campus Way and lst Avenue South in Federal Way, Washington as shown on the Vicinity Map in Figure 1. The project site consists of parcel number 4159200715. Discussions regarding site conditions are presented in this report, together with conclusions and recommendations pertaining to site preparation, excavations, foundations, structural fill, utility trench backfill, drainage, and erosion control. To aid in the preparation of this report, we have been provided with a land survey and conceptual site plan. The survey was prepared be Barghausai Consulting Engineers, Inc, and is titled, "ALTA/NSPS Land Titled Survey — A Portion of the NE1/4 of the SE1/4 of Sec. 19, TWR 21 North, RGE. 4 East, W.M. — City of Federal Way, King County WA.,” dated September 17, 2016. The conceptual site plan does not indude the name of the author and is titled, "Federal Way, WA — Conceptual Site Option 4 (drivethru)," dated September 22, 2016 (corrected). A site plan showing the approximate exploratory soil boring locations is presented in Figure 2 following the text of this report. A description of the field investigation as well as the exploratory soil boring logs and laboratory test results are presented in Appendix A. Appendix B contains a guide to aid in the development of earthwork specifications. Pavement design guidelines are presented in Appendix C. The recommendations in the main text of the report have precedence over the more general specifications in the appendices. PURPOSE AND SCOPE This investigation was conducted to evaluate the subsurface soil and groundwater conditions at the site, to develop geotechnical engineering recommendations for use in project design and to provide criteria for site preparation and earthwork construction. Offices Serving The Western United States 4303 —198s' St sw • Lynnwood, Washington 98036 • (425) 485-5519 • Fax: (425) 485-6837 AM KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 2 Our services were performed in general accordance with our proposal for this project, dated October 12, 2016 (Krazan proposal number G16025WAP). The geotechnical services performed for this project generally include the following: • Exploration of the subsurface soil and groundwater conditions by conducting two (2) soil borings using a subcontracted drill rig; • A site plan showing the soil boring locations; • Comprehensive soil logs including soil stratification and classification, and groundwater levels where applicable; ■ Recommendations for foundation design including foundation type, allowable foundation bearing pressure, anticipated settlements (both total and differential), coefficient of horizontal friction, and frost penetration depth; • Recommendations for seismic design considerations, including site coefficient and ground acceleration based on the 2012/2015 International Building Code (IBC); • Construction and excavation considerations, topsoil/unsuitable soil stripping depth, identification of potentially problematic soil or groundwater conditions, and approximate depth of over -excavation if required; • Recommendations for structural fill materials, placement, and compaction; • General recommendations for site drainage and erosion control. PROPOSED CONSTRUCTION It is our understanding that the proposed development will include a new dental office. Preliminary plans indicate that the planned development will be located in an existing parking lot area. Significant re -grading is not anticipated. New underground utilities will likely be installed, connecting nearby utilities with the planned development. SITE CONDITIONS The property is located in a retail area on the eastern side of SW Campus Drive, approximately 400 feet northwest of 1"' Avenue South. The proposed development is currently a paved parking lot. The planned building area is nearly level, with landscaping along the northern, southern and western sides of the property. A sidewalk and additional paved parking areas are located in the eastern portion of the site. A concrete retaining wall, approximately 5 to 6 feet tall, is located in the western portion of the property, with a stormwater swale near the toe of the wall along SW Campus Drive. Site plans indicate that the western portion of the parcel includes a stormwater easement with a subsurface vault below the parking lot. Krazan & Associates, Inc. Offices Serving The Western United States KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 3 According to the ALTA/NSPS Land Title Survey by Barghausen Associates Consulting Engineers, Inc., the elevation across the site ranges from approximately 232 feet in the stormwater swale near the southwestern corner of the parcel, to about 245 feet in the parldng lot area near the northeastern corner of the site. The site is bordered by commercial properties to the north, east and south, including a grocery store north to the north and a restaurant to the southeast. SW Campus Drive borders the site to the west. GEOLOGIC SETTING The "Geologic Map of the Poverty Bay 7.5' Quadrangle, King and Pierce Counties, Washington," by D.B. Booth, H.H. Waldron, and K.G. Troost (USGS 2004) indicates that the site area is underlain by Quaternary Vashon recessional outwash (Qvr), with Quaternary Vashon ice -contact deposits (Qvi) and Quaternary Vashon glacial till (Qvt) mapped nearby. Recessional outwash typically consists of poorly to moderately sorted, medium dense sand and gravel with cobbles. Ice -contact deposits are generally described as poorly sorted sand and gravel in a silty matrix, possibly including lenses of glacial till. Glacial till typically consists of a very compact, unsorted mixture of clay, silt, sand, gravel, cobbles and boulders. FIELD INVESTIGATION Two (2) exploratory soil borings were completed to evaluate the subsurface soil and groundwater conditions in the proposed development area. The soil borings were completed on November 29, 2016 with a subcontracted drill rig, and the soil borings extended to depths of approximately 21.5 feet to about 31.5 feet below the existing ground surface. A geologist and engineer from Krazan and Associates were present during the explorations, examined the soil and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the explorations. The approximate locations of the soil borings are shown on the Site Plan in Figure 2. Representative samples of the subsurface soils encountered in the geotechnical explorations were collected and sealed in plastic bags. The soils encountered in the exploratory soil borings were visually classified in general accordance with the Unified Soil Classification System (USCS). A more detailed description of the field investigation is presented in Appendix A. SOIL PROFILE AND SUBSURFACE CONDITIONS The information provided below includes a brief summary of the materials encountered in the soil explorations. Detailed soil logs are presented in Appendix A. Krazan & Associates, Inc. Offices Serving The Western United States AXIA KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 4 Soil boring B-1 was located in the southern portion of the proposed building pad. Boring B-1 encountered approximately 2.0 inches of asphalt overlying about 3.0 inches of crushed rock. Underlying the crushed rock, soil Boring B-1 encountered medium dense to very dense, brown gravel with sand to a depth of about 12.0 feet below existing grade. We interpreted the brown gravel with sand to be compacted fill material. Below the fill material, the soil boring primarily encountered very stiff, gray silt with clay and trace sand to the depth explored of approximately 26.5 feet below the ground surface. We interpreted the silt with clay to be native lacustrine deposits (ancient lake bed sediment). Soil boring B-2 was located in the northwestern portion of the proposed building pad. Boring B-2 encountered approximately 3.0 inches of asphalt overlying about 2.0 inches of crushed rock. Underlying the crushed rock, soil Boring B-2 encountered medium dense to very dense, brown gravel with sand to a depth of about 16.0 feet below existing grade. We interpreted the brown gravel with sand to be compacted fill material. Below the fill material, the soil boring encountered very stiff to hard, gray silt with clay and trace sand to the depth explored of approximately 31.5 feet below the ground surface. We interpreted the silt with clay to be native lacustrine deposits (ancient lake bed sediment). There is a potential for cobbles and there may be debris in the fill material. There is also the potential for layers of organic topsoil, loose/soft soils, and/or undocumented fill in unexplored areas of the site. GROUIN'DWATER The soil borings were checked for the presence of groundwater during drilling operations. Groundwater seepage was observed at a depth of approximately 11.0 feet in B-1 and at a depth of about 15.0 feet in B-2 during the geotechnical explorations. We interpreted the groundwater seepage to be perched groundwater. Perched water occurs when surface water infiltrates through less dense, more permeable soils and accumulates on top of a relatively low permeability soil layer. 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 perched water to decrease during drier times of the year and increase during wetter periods. It should be recognized that groundwater elevations may fluctuate with time. The groundwater level will be dependent upon seasonal precipitation, irrigation, land use, and climatic conditions, as well as other factors. Therefore, groundwater levels at the time of the field investigation may be different from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report. Krazan & Associates, Inc. Offices Serving The Western United States hk5 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 5 GEOLOGIC HAZARDS Erosion Concern/Hazard The Natural Resources Conservation Services (MRCS) map for King County indicates that the soils in the site area consist of Everett Alderwood Gravelly Sandy Loams, 6 to 15 percent slopes (EwC). The mapped soil unit is described as having a moderate potential for soil erosion when exposed. It has been our experience that soil erosion potential can be minimized through landscaping and surface water runoff control. Typically, erosion of exposed soils will be most noticeable during periods of rainfall and may be controlled by the use of normal temporary erosion control measures, such as silt fences, hay bales, mulching, control ditches or diversion trenching, and contour furrowing. Erosion control measures should be in place before the onset of wet weather. Seismic. I i a;-ird The 2015 International Building Code (IBC), Section 1613.3.2, refers to Chapter 20 of ASCE-7 for Site Class Definitions. It is our opinion that the overall soil profile corresponds to Site Class D as defined by Table 20.3-1 "Site Class Definitions," according to the 2010 ASCE-7 Standard, Site Class D applies to a "stiff soil" profile. The seismic site class is based on a soil profile extending to a depth of 100 feet. The soil borings on this site extended to a maximum depth of 31.5 feet and this seismic site class designation is based on the assumption that similar soil conditions continue below the depth explored. We referred to the U.S. Geological Survey (USGS) Earthquake Hazards Program Website and 2012/2015 IBC to obtain values for Ss, Sms, SDs, S1, Smri, SDI, Fa, and F,.. The USGS website includes the most updated published data on seismic conditions. The seismic design parameters for this site are presented in the following table: Krazan & Associates, Inc. Offices Serving The Western United States M• KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 6 Table 1: Seismic Design Parameters (Reference: 2015 IBC Section 1613.3.2, ASCE, and USGS) ismic Item Value ite Class D Coefficient Fa F 1.000 Sa 1.287 g SMs 1.287 g Sns 0.858 g Site Coefficient Fy 1.504 S1 0.496 g SMl 0.746 g SDI 0.497 g Additional seismic considerations include liquefaction potential and amplification of ground motions by soft soil deposits. The liquefaction potential is highest for loose sand with a high groundwater table. The native soils primarily consisting of stiff to hard silt with clay that are interpreted to underlie the site are considered to have a low potential for liquefaction and amplification of ground motion. CONCLUSIONS AND RECOMMENDATIONS General It is our opinion from a geotechnical standpoint that the site is compatible with the proposed development, provided that our geotechnical recommendations are incorporated into project plans and are implemented during construction. Soil Conditions: Our soil explorations generally encountered medium dense to very dense gravel with sand to depths ranging from about 12 to 16 feet, overlying very stiff to hard silt with clay soils. The gravel with sand is interpreted to be compacted fill material, and the underlying silt with clay soils are interpreted to be native lacustrine deposits (ancient lake bed sediment). The silt and clay appear to be partially consolidated. Foundations: Based on our explorations, conventional spread foundations bearing on the medium dense to very dense fill material should provide adequate support for the planned structures. Krazan & Associates, Inc. Offices Serving The Western United States M-1 KRAZAN & ASSOCIATES, INC. KANo. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 7 It is our understanding that there is an underground stormwater vault along the western edge of the proposed building pad. The proposed building might apply surcharge loads to the vault walls if the western footing line incorporates a standard design depth next to the stonnwater easement. Accordingly, consideration should be given to the proposed depth and location of the western foundation line to minimize surcharge loads. Detailed geotechnical engineering recommendations for foundation design are presented in this report. Moisture Sensitive Soils: The granular fill materials encountered in our explorations are not considered to be moisture sensitive. However, the underlying native silty clay soils are considered to be moisture sensitive and will be difficult or impossible to compact in wet conditions. Based on our explorations, the moisture sensitive materials were encountered approximately 12 to 16 feet below grade. The moisture content of the silty soils is important in determining if the soils can be used as structural fill at the time of construction. Krazan and Associates is available on request to evaluate the suitability of the on -site soils for use as structural fill material during earthwork construction. Site Pre aration General site clearing should include removal of vegetation; trees and associated root systems; wood; abandoned utilities; structures including foundations, basement walls and floors; rubble; and rubbish. Site stripping should extend until all organics in excess of 3 percent by volume are removed. These materials will not be suitable for use as structural fill. However, stripped topsoil may be stockpiled and used in landscape or non-structural areas. After stripping operations, the building pad and pavement areas should be proof -rolled and visually inspected to identify any areas of sofdloose soil. Any remaining loose soils should be excavated to expose firm native soils. The resulting excavations should be filled with approved structural fill. Structural fill material should be within f 2 percent of the optimum moisture content, and the soils should be compacted to a minimum of 95 percent of the maximum dry density as determined by ASTM D1557 Test Method. During wet weather conditions, subgrade stability problems and grading difficulties may develop due to excess moisture, disturbance of sensitive soils and/or the presence of perched groundwater. Construction during the extended periods of wet weather could result in the need to remove wet disturbed soils if they cannot be suitably compacted due to elevated moisture contents. Some of the on - site soils have significant silt content and are considered to be moisture sensitive, and can be easily disturbed when wet. If over -excavation is necessary, it should be confirmed through continuous monitoring and testing by a qualified geotechnical engineer or geologist. Soils that have become unstable may require drying to near their optimal moisture content before compaction is feasible. Krazan & Associates, Inc. Offices Serving The Western United States KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 8 Selective drying may be accomplished by scarifying or windrowing surficial material during extended periods of dry, warm weather (typically during the summer months). If the soils cannot be dried back to a workable moisture condition, remedial measures may be required. . General project site winterization should consist of the placement of aggregate base and the protection of exposed soils during the construction phase. It should be understood that even if Best Management Practices (BMPs) for wintertime soil protection are implemented and followed there is a significant chance that moisture disturbed soil mitigation work will still be required. Any buried structures encountered during construction should be properly removed and backfilled. Excavations, depressions, or soft and pliant areas extending below the planned finish subgrade levels should be excavated to expose firm undisturbed native soil, and backfilled with structural fill. In l general, any septic tanks, underground storage tanks, debris pits, cesspools, or similar structures should } be completely removed. Concrete footings should be removed to an equivalent depth of at least 3 feet below proposed footing elevations or as recommended by the geotechnical engineer. The resulting excavations should be backfilled with structural fill. A representative of our firm should be present during all site clearing and grading operations to observe, test and evaluate earthwork construction. This testing and observation is an integral part of our service, as acceptance of earthwork construction is dependent upon compaction and stability of the material. The geotechnical engineer may reject any material that does not meet compaction and stability requirements. Further recommendations, contained in this report, are predicated upon the assumption that earthwork construction will conform to the recommendations set forth in this section and in the Structural Fill Section of this report. Temporary Excavations The on -site soils have variable cohesion strengths, therefore the safe angles to which these materials may be cut for temporary excavations is variable, as the soils may be prone to caving and slope failures in temporary excavations deeper than 4 feet. Temporary excavations in medium dense soils should be sloped no steeper than 1.5H:1V (horizontal to vertical) where room permits. The dense to very dense granular soils may be sloped to inclinations of 1H:1V. If groundwater seepage is encountered in temporary excavations, then we anticipate that flatter inclinations might be necessary. All temporary cuts should be in accordance with Washington Administrative Code (WAC) Part N, Excavation, Trenching, and Shoring. The temporary slope cuts should be visually inspected daily by a qualified person during construction work activities and the results of the inspections should be included in daily reports. The contractor is responsible for maintaining the stability of the temporary cut slopes and minimizing slope erosion during construction. The temporary cut slopes should be covered with plastic sheeting to help minimize erosion during wet weather and the slopes should be Krazan & Associates, Inc. Offices Serving The Western United States N KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 9 closely monitored until the permanent retaining systems are complete. Materials should not be stored and equipment operated within 10 feet of the top of any temporary cut slope. A Krazan & Associates geologist or geotechnical engineer should observe, at least periodically, the temporary cut slopes during the excavation work. The reasoning for this is that all soil conditions may not be fully delineated by the limited sampling of the site from the geotechnical explorations. In the case of temporary slope cuts, the existing soil conditions may not be fully revealed until the excavation work exposes the soil. Typically, as excavation work progresses, the maximum inclination of the temporary slope will need to be evaluated by the geotechnical engineer so that supplemental recommendations can be made. Soil and groundwater conditions can be highly variable. Scheduling for soil work will need to be adjustable, to deal with unanticipated conditions, so that the project can proceed smoothly and required deadlines can be met. If any variations or undesirable conditions are encountered during construction, Krazan & Associates should be notified so that supplemental recommendations can be made. Structural Fili 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. 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 subsection of this report prior to beginning fill placement. Typically, imported all-weather structural fill material should consist of well -graded gravel, or sand and gravel mixture, with a maximum grain size of 3 inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). All structural fill material should be submitted for approval to the geotechnical engineer at least 48 hours prior to delivery to the site. Fill soils should be placed in horizontal lifts not exceeding 8 inches in thickness prior to compaction, moisture -conditioned as necessary, (moisture content of soil shall not vary by more than t2 percent of optimum moisture) and the material should be compacted to at least 95 percent of the maximum dry density based on ASTM D1557 Test Method. In -place density tests should be performed on all structural fill to document proper moisture content and adequate compaction. Additional lifts should not be placed if the previous lift did not meet the compaction requirements or if soil conditions are not considered stable. Krazan & Associates, Inc. Offices Serving The Western United States NU) KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 10 Foundations General: The proposed building may be supported on a conventional spread foundation system bearing on the granular medium dense or firmer soils. The medium dense to very dense granular soils at the site are interpreted to be compact fill material. We recommend that the foundation subgrade soils be evaluated during construction to determine the consistency throughout the building pad. Western Foundation Line: It is our understanding that there is an underground stormwater vault along the western edge of the proposed building pad. Based on the available information from the plans and a stormwater utility map, the proposed western building foundation may be in close proximity to the vault retaining wall. Accordingly, we recommend that the western foundation of the proposed building be deepened or moved laterally to maintain a 1 Horizontal to 1 Vertical (1H:1V) geometry between the bottom of the existing vault foundation and the bottom of the proposed building foundation. Soil Bearing: Conventional shallow spread footings supported on medium dense of firmer granular soils, or on structural fill extending to the medium dense or firmer soils, may be designed using an allowable bearing pressure of 2,000 pounds per square foot (psf) for dead plus live loads. This value may be increased by 1/3 for short duration loads such as wind or seismic loading. A representative of Krazan and Associates should evaluate the foundation bearing soil and observe structural fill placement. Footings should have a minimum embedment depth of 18 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. Footing widths should be based on the anticipated loads and allowable soil bearing pressure. Footings should have a minimum width of at least 12 inches regardless of load. Water should not be allowed to accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavations prior to placing concrete. Water should not be allowed to collect in the foundation excavations. Structural Fill in Footing Areas: If structural fill is placed beneath foundations, the footing trenches would need to be widened on both sides of the footing a distance equal to one-half of the thiclmess of the structural fill layer to be placed below the bottom of the footing. Structural fill material should consist of well -graded gravel, or sand and gravel mixture, with a maximum grain size of 3 inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). All structural fill material should be submitted for approval to the geotechnical engineer at least 48 hours prior to delivery to the site. Footing excavations should be inspected to verify that the foundations will bear on suitable material. Potential Foundation Settlement: For foundations constructed as recommended, the total settlement is not expected to exceed 1-inch. Differential settlement, along a 20-foot exterior wall footing or between Krazan & Associates, Inc. Offices Serving The Western United States /Nil KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 11 adjoining column footings, should be less than 1/2-inch. Most settlement is expected to occur during construction, as the loads are applied. However, additional post -construction settlement may occur if the foundation soils are flooded or saturated. It should be noted that the risk of liquefaction is considered low, given the composition and density of the native, on -site soils. Footing Drains: Seasonal rainfall, water ran -off, and the normal practice of watering trees and landscaping areas around the proposed structures, should not be permitted to flood and/or saturate foundation subgrade soils. To prevent the buildup of water within the footing areas, continuous footing drains (with cleanouts) should be provided at the bases of the footings. The footing drains should consist of a minimum 4-inch diameter rigid perforated PVC pipe, sloped to drain, with perforations placed near the bottom. The drainpipe should be enveloped by 1-inch sized washed rock in all directions and wrapped with filter fabric to prevent the migration of silt and clay into the drain. If free -draining materials are exposed in the foundation subgrade, then footing drains may not be necessary. This can be evaluated during building pad excavation. Design Parameters — Lateral Resistance: Resistance to lateral footing displacement can be computed using an allowable friction factor of 0.35 acting between the bases of foundations and the supporting subgrade soil. Lateral resistance for footings can alternatively be developed using an allowable equivalent fluid passive pressure of 250 pounds per cubic foot (pcf) acting against the appropriate vertical footing faces (neglecting the upper 12 inches). The allowable friction factor and allowable equivalent fluid passive pressure values include a factor of safety of 1.5. The frictional and passive resistance of the soil may be combined without reduction in determining the total lateral resistance. A 1 /3 increase in the above values may be used for short duration, wind and seismic loads. Soil Sulfate Content: It is our understanding that the sulfate content of soils can affect the type of concrete used for the foundations. Soil samples from each boring at about 2.5 feet in depth were sent to Am Test, Inc. in Kirkland, Washington for water-soluble sulfate testing using method EPA 300.0. Laboratory test results are presented in Table 1 below. C'�ilalr. I: SoliE€ite Milt':,i� Cstintent of Soils Sample I.D. I Test Result (µg/g) I Test Result (% by mass) Sample 1 (B-1 at 2.5') < 10 I < 0.0010 Sample 2 (B-2 at 2.5') <10 Krazan & Associates, Inc. Offices Serving The Western United States NZZ < 0.0010 J KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 12 According to ACI 318-14 Table 19.3.1.1 — "Exposure categories and classes," both samples would be included in Sulfate Class SO with (SO42-) < 0.10 percent by mass. According to ACI 318-14 Table 19.3.2.1— "Requirements for concrete by exposure class," there are no cementitious materials type restrictions for exposure class SO soils. Floor Slabs and Exterior Flatwork For building floor slab subgrades prepared in accordance with the recommendations presented in the Site Preparation section of this report, floor slabs may be designed using a modulus of subgrade reaction value of k = 200 pounds per cubic inch (pci) for slabs supported on medium dense or firmer soils or on structural fill extending to medium dense or firmer soils. In areas where it is desired to reduce floor dampness, such as areas covered with moisture sensitive floor coverings, we recommend that concrete slab -on -grade floors be underlain by a water vapor retarder system. The water vapor retarder should consist of a plastic vapor retarder sheeting underlain by a minunum of 4-inches of compacted clean (less than S percent passing the U.S. Standard No. 200 Sieve), open -graded coarse rock of %-inch maximum size. The vapor retarder sheeting should be protected from puncture damage. Moisture within the structure may be derived from water vapors, which were transformed from the moisture within the soils. This moisture vapor can travel through the vapor membrane and penetrate the slab -on -grade. This moisture vapor penetration can affect floor coverings and produce mold and mildew in the structures. To minimize moisture vapor intrusion, it is recommended that a vapor retarder be installed in accordance with ASTM guidelines. It is recommended that the utility trenches within the structures be compacted, as specified in our report, to minimize the transmission of moisture through the utility trench backfill. Under -slab drainage should be considered if floor moisture is a concern. Special attention to the immediate drainage and irrigation around the buildings is recommended. Positive drainage should be established away from the structures and should be maintained throughout the lives of the structures. Water should not be allowed to collect adjacent to the structures. Over -irrigation within landscaped areas adjacent to the structures should not be performed. In addition, ventilation of the structures may be prudent to reduce the accumulation of interior moisture. Lateral Earth Pressures and Retaining Wails We have developed criteria for the design of retaining or below grade walls. Our design parameters are based on retention of the in -place soils. The parameters are also based on level, well -drained wall backfill conditions. Walls may be designed as "restrained" retaining walls based on "at -rest" earth pressures, plus any surcharge on top of the walls as described below, if the walls are braced to restrain movement and/or movement is not acceptable. Unrestrained walls may be designed based on "active" earth pressure, if the walls are not part of the buildings and some movement of the retaining walls is Krazan & Associates, Inc. Offices Serving The Western United States �Z� KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 13 acceptable. Acceptable lateral movement equal to at least 0.2 percent of the wall height would warrant the use of "active" earth pressure values for design. 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 35 pcf for yielding (active condition) walls, and 55 pcf for non -yielding (at -rest condition) walls. The stated lateral earth pressures do not include the effects of hydrostatic pressure generated by water accumulation behind the retaining walls or loads imposed by construction equipment, slopes, foundations or roadways adjacent to the wall (surcharge loads). To minimize the lateral earth pressure and prevent the buildup of water pressure against the walls, continuous footing drains (with cleanouts) should be provided at the bases of the walls. The footing drains should consist of a minimum 4-inch diameter perforated pipe, sloped to drain, with perforations placed near the bottom. The drainpipe should be enveloped by 6 inches of washed gravel in all directions wrapped in filter fabric to prevent the migration of silt and clay into the drain. The wall fill adjacent to and extending a lateral distance of at least 2 feet behind the walls should consist of free -draining granular material. All free -draining backfill should contain less than 3 percent fines (passing the U.S. Standard No. 200 Sieve) based upon the fraction passing the U.S. Standard No. 4 Sieve with at least 30 percent of the material being retained on the U.S. Standard No. 4 Sieve. Alternatively, a drainage composite may be "used. It should be realized that the primary purpose of the free -draining material is the reduction of hydrostatic pressure. Some potential for the moisture to contact the back face of the wall may exist, even with treatment, which may require that more extensive waterproofing be specified for walls, which require interior moisture sensitive finishes. We recommend that the wall fill be compacted to at least 95 percent of the maximum dry density based on ASTM D 1557 Test Method. In -place density tests should be performed to verify adequate compaction. Soil compactors place transient surcharges on the backfill. Consequently, only light hand operated equipment is recommended for fill compaction within 3 feet of walls so that excessive stress is not imposed on the walls. Erosion and Sediment Control. Erosion and sediment control (ESC) is used to minimize the transportation of sediment to wetlands, streams, lakes, drainage systems, and adjacent properties. Erosion and sediment control measures should be implemented and these measures should be in general accordance with local regulations. As a minimum, the following basic recommendations should be incorporated into the design of the erosion and sediment control features of the site; 1) Phase the soil, foundation, utility and other work, requiring excavation or the disturbance of the site soils, to take place during the dry season (generally May through September). However, Krazan & Associates, Inc. Offices Serving The Western United States AZ-` KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 14 provided precautions are taken using Best Management Practices (BMP's), grading activities can be undertaken during the wet season (generally October through April), but it should also be known that this may increase the overall cost of the project. 2) All site work should be completed and stabilized as quickly as possible. 3) Additional perimeter erosion and sediment control features may be required to reduce the possibility of sediment entering the surface water. This may include additional silt fences, silt fences with a higher Apparent Opening Size (AOS), construction of a berm, or other filtration systems. 4) Any runoff generated by dewatering discharge should be treated through construction of a j sediment trap if there is sufficient space. If space is limited, other filtration methods will need to be incorporated. Groundwater Influence on Structures and Earthwork Construction Groundwater seepage was encountered in the soil borings at the time of our site visit. It should be recognized that groundwater elevations may fluctuate with time. The groundwater level will be i dependent upon seasonal precipitation, irrigation, land use, and climatic conditions, as well as other l factors. Therefore, groundwater levels at the time of the field investigation may be different from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report. If groundwater is encountered during construction, we should observe the conditions to determine if dewatering will be needed. Design of temporary dewatering systems to remove groundwater should be the responsibility of the contractor. If earthwork is performed during or soon after periods of precipitation, the subgrade soils may become saturated. These soils may "pump," and the materials may not respond to densification techniques. Typical remedial measures include: disking and aerating the soil during dry weather; mixing the soil with drier materials; removing and replacing the soil with an approved fill material. A qualified geotechnical engineering fine should be consulted prior to j implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations. If earthwork is performed during or soon after periods of precipitation, the subgrade soils may become saturated. These soils may "pump," and the materials may not respond to densification techniques. Typical remedial measures include: disking and aerating the soil during dry weather; mixing the soil with drier materials; removing and replacing the soil with an approved fill material. A qualified geotechnical engineering firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations. Krazan & Associates, Inc. Offices Serving The Western United States MIS; KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 15 Drains a and Landscaping The ground surface should slope away from building pads and pavement areas, toward appropriate drop inlets or other surface drainage devices. It is recommended that adjacent exterior grades be sloped a minimum of 2 percent for a minimum distance of 5 feet away from structures. We recommend the installation of foundation drains with cleanouts for this project. The foundation drains should consist of a minimum 4-inch diameter perforated pipe, sloped to drain, with perforations placed near the bottom and enveloped by 6 inches of washed gravel in all directions and filter fabric to prevent the migration of fines into the drains. Roof drains should be tightlined away from foundations to a suitable outlet. Roof drains should not be connected to the footing drains. Subgrade soils in pavement areas should be inclined at a minimum of 1 percent and drainage gradients should be maintained to carry all surface water to collection facilities, -and._suitable outlets. These gradmshould be rnaintaiucd f6 the life af'the developi-noo.- Specific recommendations for and design of storm water disposal systems or septic disposal systems are beyond the scope of our services and should be prepared by other consultants that are familiar with design and discharge requirements. Utility Trench Backfill Utility trenches should be excavated according to accepted engineering practices following Occupational Safety and Health Administration (OSHA) standards, by a contractor experienced in such work. The responsibility for the safety of open trenches should be borne by the contractor. Traffic and vibration adjacent to trench walls should be minimized; cyclic wetting and drying of excavation side slopes should be avoided. Depending upon the location and depth of some utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation. All utility trench backfill should consist of structural fill. Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. The upper 5 feet of utility trench backfill placed in pavement areas should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. Below 5 feet, utility trench backfill in pavement areas should be compacted to at least 90 percent of the maximum dry density based on ASTM Test Method D1557. Pipe bedding should be in accordance with the pipe manufacturer's recommendations. - The contractor is responsible for removing all water -sensitive soils from the trenches regardless of the backfill location and compaction requirements. The contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction. Krazan & Associates, Inc. Offices Serving The Western United States Alb KRAZAN & ASSOCIATES, INC. KANo. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 16 Pavement Desi n The near -surface subgrade soils generally consist of sand with gravel. These soils are rated as fair to good for pavement subgrade material. We estimate that the subgrade will have a California Bearing Ratio (CBR) value of 12 and a modulus of subgrade reaction value of k = 200 pci, provided the subgrade is prepared in general accordance with our recommendations. Appropriate lab tests can be performed for confirmation of these recommendations when the pavement areas have been defined. Depending on the existing soil conditions, at the time of subgrade preparation, we recommend that, at a minimum, 12 inches of the existing subgrade material be moisture conditioned (as necessary) and compacted to prepare for the construction of pavement sections. The subgrade should be compacted to at least 95 percent of the maximum dry density as determined by ASTM Test Method D1557. In place density tests should be performed to verify proper moisture content and adequate compaction. The subgrade may be proof rolled in lieu of the in -place density tests, particularly if dense, native soils are observed. In this case, moisture conditioning and compaction work may not be required. Alternatively, if moisture sensitive subgrade soils prohibit the use of vibratory compaction, it may be necessary to remove disturbed soil and replace the disturbed materials with clean crushed rock fill. The recommended flexible and rigid pavement sections are based on design CBR and modulus of subgrade reaction (k) values that would be achieved, only following proper subgrade preparation. It should be noted that subgrade soils that are relatively high in silt or clay content may be highly sensitive to moisture conditions. The subgrade strength and performance characteristics of a silty or clayey subgrade material may be dramatically reduced if this material becomes wet. Traffic load information was not provided, however, based on our knowledge of the proposed project, we expect the traffic to be relatively light consisting mostly of passenger automobiles. For heavier traffic areas such as loading and unloading areas, as well as truck routes, we have provided heavy duty pavement sections. The following tables show the recommended pavement sections for light duty and heavy duty use. Krazan & Associates, Inc. Offices Serving The Western United States PIL-7 KR.AZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 17 ASPHALTIC CONCRETE (FLEXIBLE) PAVEMENT LIGHT DUTY (PARKING !AREA) M ihul.tic C'oiicret[ Agar aft_ i�l3ast'' C`tfni atl:etl':. r' 2.0 in. 6.0 in. 12.0 in. * 95% compaction based on ASTM Test Method D1557 **A proof roll maybe performed in lieu of in place density tests ASPHALTIC CONCRETE (FLEXIBLE) PAVEMENT 14F,AVY DUTY (HEAVY TRUCK AREA) As 1lzaltii Concrete x, rregate`13asc' Cam iaeted Bab 5rade." 3.0 in. 6.0 in. 12.0 in. * 95% compaction based on ASTM Test Method D1557 * * A proof roll may be performed in lieu of in place density tests PORTLAND CEMENT CONCRETE (RIGID) PAVEMENT [�lin_rtiun� 1't C'. A Sze raj.�,8ase� C{��;t rl�tec3,Sutiradc* ** 6.0 in. 6.0 in. 12.0 in. * 95%compaction based onASTMTestMethodD1557 * * A proof roll may be performed in lieu of in place density tests The asphaltic concrete depth in the flexible pavement tables should be a surface course type asphalt, such as Washington Department of Transportation (WSDOT)'/z inch HMA. The rigid pavement design is based on a Portland Cement Concrete (PCC) mix that has a 28 day compressive strength of 4,000 pounds per square inch (psi). The design is also based on a concrete flexural strength or modulus of rupture of 550 psi. Testing and Inspection A representative of Krazan & Associates, Inc. should be present at the site during the earthwork activities to confirm that actual subsurface conditions are consistent with the exploratory fieldwork. This activity is an integral part of our services as acceptance of earthwork construction is dependent upon compaction testing and stability of the material. This representative can also verify that the intent of these recommendations is incorporated into the project design and construction. Krazan & Associates, Inc. will not be responsible for grades or staking, since this is the responsibility of the Prime Contractor. Furthermore, Krazan & Associates is not responsible for the contractor's procedures, methods, scheduling or management of the work site. Krazan & Associates, Inc. Offices Serving The Western United States KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 18 LiMTfATIGNS Geotechnical engineering is one of the newest divisions of Civil Engineering. This branch of Civil Engineering is constantly improving as new technologies and understanding of earth sciences improves. Although your site was analyzed using the most appropriate current techniques and methods, undoubtedly there will be substantial future improvements in this branch of engineering. In addition to improvements in the field of geotechnical engineering, physical changes in the site either due to excavation or fill placement, new agency regulations or possible changes in the proposed structure after the time of completion of the soils report may require the soils report to be professionally reviewed. In light of this, the owner should be aware that there is a practical limit to the usefulness of this report without critical review. Although the time limit for this review is strictly arbitrary, it is suggested that two years be considered a reasonable time for the usefulness of this report. Foundation and earthwork construction is characterized by the presence of a calculated risk that soil and groundwater conditions have been fully revealed by the original subsurface investigation. This risk is derived from the practical necessity of basing interpretations and design conclusions on limited sampling of the earth. Our report, design conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. The recommendations made in this report are based on the assumption that soil conditions do not vary significantly from those disclosed during our field investigation. The findings and conclusions of this report can be affected by the passage of time, such as seasonal weather conditions, manmade influences, such as construction on or adjacent to the site, natural events such as earthquakes, slope instability, flooding, or groundwater fluctuations. If any variations or undesirable conditions are encountered during construction, the geotechnical engineer should be notified so that supplemental recommendations can be made. The conclusions of this report are based on the information provided regarding the proposed construction. If the proposed construction is relocated or redesigned, the conclusions in this report may not be valid. The geotechnical engineer should be notified of any changes so that the recommendations can be reviewed and reevaluated. Misinterpretations of this report by other design team members can result in project delays and cost overruns. These risks can be reduced by having Krazan & Associates, Inc. involved with the design teams meetings and discussions after submitting the report. Krazan & Associates, Inc. should also be retained for reviewing pertinent elements of the design team's plans and specifications. Contractors can also misinterpret this report. To reduce this, risk Krazan & Associates. Inc. should participate in pre bid and preconstruction meetings, and provide construction observations during the site work. This report is a geotechnical engineering investigation with the purpose of evaluating the soil conditions in terms of foundation design. The scope of our services did not include any environmental site Krazan & Associates, Inc. Offices Serving The Western United States Aria KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 19 assessment for the presence or absence of hazardous and/or toxic materials in the soil, groundwater or atmosphere, or the presence of wetlands. Any statements or absence of statements, in this report or on any soils log regarding odors, unusual or suspicious items, or conditions observed are strictly for descriptive purposes and are not intended to convey engineering judgment regarding potential hazardous and/or toxic assessments. The geotechnical information presented herein is based upon professional interpretation utilizing standard engineering practices and a degree of conservatism deemed proper for this project. It is not warranted that such infonnation and interpretation cannot be superseded by future geotechnical developments. We emphasize that this report is valid for this project as outlined above, and should not be used for any other site. Our report is prepared for the exclusive use of our client. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. If you have any questions, or if we may be of further assistance, please do not hesitate to contact our office at (425) 485-5519. Respectfully submitted, KRAZAN & ASSOCIATES, INC. JGL/MDR Krazan & Associates, Inc. Offices Serving'Ibe Western United States pr3® Vicinity Map N (Not to Scale) 53� � - �►' rHSr s aaam srr x st r Osr w. L g ` Approximate Site Area S 34tTF1 ST 4 S 344ma N 535GMST �t 15f Northwest of S. 348th St. and 1st Ave. S. - Federal Way, WA Relorenw: The VIJNIy Map Is based on a USGS lopogrophle mop aged. Tovarty ling Quodrangle - Washinglon - 7.5-10inute Sodas," dew 2014. jraz;auL & ASSOCIATES,INC. Federal Way Dental - Northwest of S. 348th St. and 1st Ave. S. - Federal Way, WA Date: November 2016 Project Number: 062 -16006 Drawn By: NG Figure 1 Not to scale NJl Site Plan (Not to Scale) I Proposed + Building i i i I 1 l 1 1 i 1 1 ! Approximate -l- -Site Boundary_, 1� 1 i .1 .1 .1 .1 \ A \ E LEGEND B-1 Number and Approximate {� Location of Xrazan Soll Boring `r on 11-29-16. Mz Reforenre: M pfan Is based on a drawing provided by Ctlonl Titled, 'Faderal Way. WA- Concept Sji8 Op1lon 4," daled Septoraber 22, 20% APPENDIX A FIELD INVESTIGATION AND LABORATORY TESTING Field lsivestigafi The field investigation consisted of a surface reconnaissance and a subsurface exploration program. Two (2) geotechnical borings were drilled and sampled for the subsurface exploration at this site. The soil borings were completed on November 29, 2016 by a Krazan subcontractor utilizing a truck - mounted drill rig. The soil borings were advanced to depths ranging from about 21.5 to 31.5 feet below the existing ground surface. The approximate exploratory boring locations are shown on the Site Plan (Figure 2). The depths shown on the attached soil boring logs are from the existing ground surface at the time of our exploration. The drilled borings were advanced using a truck mounted, auger drilling rig. Soil samples were obtained by using the Standard Penetration Test (SPT) as described in ASTM Test Method D1586. The Standard Penetration Test and sampling method consists of driving a standard 2-inch outside -diameter, split barrel sampler into the subsoil with a 140-pound hammer free falling a vertical distance of 30 inches. The summation of hammer -blows required to drive the sampler the final 12-inches of an 18- inch sample interval is defined as the Standard Penetration Resistance, or N-value. The blow count is presented graphically on the boring logs in this appendix. The resistance, or "N" value, provides a measure of the relative density of granular soils or of the relative consistency of cohesive soils. The soils encountered were logged in the field during the subsurface exploration and, with supplementary laboratory test data, are described in accordance with the Unified Soil Classification System (USCS). All samples from the explorations were returned to our laboratory for evaluation. The logs of the soil borings along with the laboratory test results are presented in this appendix. L aboi-MQn Testing The laboratory testing program was developed primarily to determine the index properties of the soils. Test results were used for soil classification and as criteria for determining the engineering suitability of the subsurface materials encountered. Sulfate testing was also conducted on near -surface soil samples. Test results from AM TEST, Inc. are included in this appendix. Krazan and Assodates, I ne. Offices Serving The Western United States n3� Soil Classification USCS Soil Classification Major Division Group Description Coarse- Grained Soils < 50% passes #200 sieve Gravel and Gravelly Soils < 50% coarse fraction passes #4 sieve Gravel (with little or no fines) GW Well -Graded Gravel GP Poorly Graded Gravel Gravel (with > 12% fines) GM Silty Gravel GC Clayey Gravel Sand and Sandy Soils > 50% coarse fraction passes #4 sieve Sand (with little or no fines) SW Well -Graded Sand SP Poorly Graded Sand Sand (with > 12% fines) SM Silty Sand SC Clayey Sand Fine- Grained Soils Silt and Clay Liquid Limit < 50 ML Silt CL Lean Clay OL Organic Silt and Clay (Low Plasticity) > 50% passes #200 sieve Silt and Clay Liquid Limit> 50 MH Inorganic Silt CH Inorganic Clay OH Organic Clay and Silt (Med. to High Plasticity) Highly Organic Soils PT Peat Relative Density with Respect to SPT N-Value Coarse -Grained Soils Fine -Grained Soils Density N-Value (BlowslFt) Density N-Value (Blows/Ft) Very Loose 0-4 Very Soft 0-1 Loose 5 -10 Soft 2-4 Medium Dense 11 - 30 Medium Stiff 5-8 Dense 31 - 50 Stiff 9 -15 Very Dense > 50 Very Stiff 16 - 30 Hard > 30 KN LOG OF EXPLORATORY BORING B-1 KRAZAN AND ASSOCIATES, INC. PROJECT: Federal Way Dental DATE:11129116 4303 - 198th St SW PROJECT NO.: 062-16008 PAGE: 1 of 1 Lynnwood, WA Y LOGGED BY: JL/NG SURFACE ELEVATION: CONTRACTOR: Geologic Drill BORING TYPE: Hollow Stem Auger SAMPLE METHOD: SPT - Split Spoon LOCATION: Federal Way, WA Imo- m Natural Moisture z y N-VALUE (GRAPH) Content MATERIAL DESCRIPTION v .. a- Uj = w 3 a o (Percent) i a > N a 10 20 30 40 10 20 30 40 c U m r. z �- w Pavement Section I ..; 5-inches of asphalt and crushed gravel 13 23 [ Fill Material Y'"rdi'; Brown gravel with sand is , s5 (medium dense to very dense, moist) r. 5 50 F:•'.wJ I 50+ soil becomes wet Silt with Clay (ML) Gray silt with clay and trace sand (very stiff, moist to wet) 15 ? `iEli a ti 't 2 24 24 Jil it }'• - soil becomes silty clay (CL-ML) 20 a`' - soil becomes silt with clay (ML) s s ,x 23 Al End of Exploratory Boring s 30 Water Level Initial: Y. Final: I Water Observations: Perched groundwater was encountered at a depth of approximately 11.0 feet below the ground surface. Notes: A 2 LOG OF EXPLORATORY BORING B-2 KRAZAN AND ASSOCIATES, INC. 4303 - 198th St SW PROJECT: Federal Way Dental DATE:11129116 Lynnwood, WA PROJECT NO.: 062-16008 PAGE:1 of 1 LOGGED BY: JL/NG SURFACE ELEVATION: CONTRACTOR: Geologic Drill BORING TYPE: Hollow Stem Auger SAMPLE METHOD: SPT - Split Spoon LOCATION: Federal Way, WA w H N VALUE (GRAPH) Natural Moisture V Content MATERIAL DESCRIPTION V ^ j N (20r IL o V m a z T y 10 20 30 40 10 30) 40 Pavement Section , •` - y" 5-inches of asphalt and crushed gravel 4e • - •� Fill Material Brown gravel with sand23 ,e 48 26 . • :. - (medium dense to very dense, moist) k 5 . r ' y 43 .' • ■wi -1 r 33 � i • : 72 26 t4 w 4W. r i +_r 15 •� _ - soil becomes wet 21. 56 Silt with Clay (ML) Gray silt with clay and trace sand (very stiff to hard, moist) 20 e 1: I 30 25 e 21 30 v 31 ,4 i End of Exploratory Boring Water Level Initial: Y Final: I Water Observations: Perched groundwater was encountered at a depth of approximately 15.0 feet below the ground surface. Notes: A% Krazan & Assoc. Sieve Analysis Mill 11111111111INUM I I IKE HIS HIM IN HIM 11111 1U1l1I111ii1111111I �iiiiiiisi-I MEN II�WIIIIY��IIII�\r 1011111111lllllR■IlAlll111 Inan IN ORION Test Results (ASTM C-136 & ASTM C-117) Opening Percent Spec.` Pass? Size Finer (Percent) (X=Fail) 1.25 100.0 1 92.4 .75 79.1 .5 55.0 .375 46.6 #4 38.7 #10 31.7 #20 26.0 #40 18.4 #60 11.1 #100 7.4 #200 5.0 Material DASu ion Brown poorly graded gravel with silt and sand Atterbe g Limits (ASTM 43181 PL= NP LL= NV PI= Class[filgation USCS (D 2487)= GP -GM AASHTO (M 145)= A-1-a Coefficients 1390 23.8682 D8g= 21.3207 D6D= 14.0109 D50= 11.0690 D30= 1.5440 D75= 0.3358 1390= 01234 Cu= 62.67 Cc= 0.76 Remarks Natural Moisture Content (ASTM D-2216): 3.0% Date Received: 12/2/16 Date Tested: 12/5/16 Tested By: Ross Goff Checked By: Corbett Mercer Title: Lab Manager (no specification provided) Location: Boring 2 Date Sampled: 11/29/16 Sample Number: 7 37-D 0 Client: Covenant Group �orProject: Proposed New Dental Office Fi ure A57 LIQUID AND PLASTIC LIMITS TEST REPORT 60 Dashed line indicates the approximate Tested By: Ross Goff Checked By: Corbett Mercer Am Test Inc. NE 126TH PL Suite CX- Kirkland, WA 98034 (425) 885-1664 L A e u e A -r o e i E s www.amtestlab.com ANALYSIS REPORT KRAZAN & ASSOCIATES, INC 4303- 198TH ST SW LYNNWOOD, WA 98036 Attention: JEFF LEAGUE Project Name: FEDERAL WAY DENTAL OFFICE PO Number: 06216008 All results reported on an as received basis. AMTEST Identification Number Client Identification Sampling Date Minerals 16-AO29973 57037-A 11/29/16, 08:00 Professional AnaVical Services Date Received: 12/06/16 Date Reported: 1/13/17 PARAMETER. RESULT UNITS p D.L. ;METHOD (ANALYST DATE Sulfate < 10 uglg 10 IEPA 300.0 JC 01/06/17 AMTEST Identification Number Client Identification Sampling Date Minerals 16-A029974 57037-C 11/29116, 10:00 PARAM �cR• . f ) RESULT . l! ITS 10 D.L. ;METHOD ANALYST DATE ; Sulfate 1< 10 lug/g 1 110 1 EPA 300.0 JC 01/06/17 !�_4(_ '4gA KathjFu� liel •-i w Am Test Inc. Professional 13600 NE 126th PL Suite C �` F ,. Analytical Services WA, 98034 Kirkland, (425) 885-1664 L a e o R a r o B 1 e s www.amtestlab.com QC Summary for sample numbers: 16-AO29973 to 16-AO29974 DUPLICATES SAMPLE # ANALYTE UN11'S ISAMPLEVALUE IDUPVALUE RPD 16-AO29973 Sulfate I ug/9 1<10 1<10 STANDARD REFERENCE MATERIALS ANALYTE I UNITS TRUE VALUE MEASURED VALUE IRECOVERY Sulfate I uglg 1200 1200 100. °Io BLANKS ANALYTE UNITS IRESULT Sulfate uglg 1<10 APPENDIX B EARTHWORK SPECIFICATIONS GENERAL When the text of the report conflicts with the general specifications in this appendix, the recommendations in the report have precedence. SCOPE OF WORK: These specifications and applicable plans pertain to and include all earthwork associated with the site rough grading, including but not limited to the furnishing of all labor, tools, and equipment necessary for site clearing and grubbing, stripping, preparation of foundation materials for receiving fill, excavation, processing, placement and compaction of fill and backfill materials to the lines and grades shown on the project grading plans, and disposal of excess materials. PERFORMANCE: The Contractor shall be responsible for the satisfactory completion of all earthwork in accordance with the project plans and specifications. This work shall be inspected and tested by a representative of Krazan and Associates, Ina, hereinafter known as the Geotechnical Engineer and/or Testing Agency. Attainment of design grades when achieved shall be certified to by the project Civil Engineer. Both the Geotechnical Engineer and Civil Engineer are the Owner's representatives. If the contractor should fail to meet the technical or design requirements embodied in this document and on the applicable plans, he shall :Hake the necessary readjustments until all work is deemed satisfactory as determined by both the Geotechnical Engineer and Civil Engineer. No deviation from these specifications shall be made except upon written approval of the Geotechnical Engineer, Civil Engineer or proj ect Architect. No earthwork shall be, performed without the physical presence or approval of the Geotechnical Engineer. The Contractor shall notify the Geotechnical Engineer at least 2 working days prior to the commencement of any aspect of the site earthwork. The Contractor agrees that he shall assume sole and complete responsibility for job site conditions during the course of construction of this project, including safety of all persons and property; that this rNuiremeut shall apply continuously and not be limited to normal working hours; and that the Contractor shall defend, indemnify and hold the Owner and the Engineers harmless from any and all liability, real or alleged, in connection with the performance of work on this proj ect, except for liability arising from the sole negligence of the Owner of the Engineers. TECHNICAL REQUIREMENTS: All compacted materials shall be densified to a density not less than 95 percent of maximum dry density as determined by ASTM Test Method D1557 as specified in the technical portion of the Geotechnical Engineering Report. The results of these tests and compliance with these specifications shall be the basis upon which satisfactory completion of work will be judged by the Geotechnical Engineer. Krazan and Assodate% I na. Offices Serving The Western United States jNLk 1 SOIL AND FOUNDATION CONDITIONS: The Contractor is presumed to have visited the site and to have familiarized himself with existing site conditions and the contents of the data presented in the soil report. The Contractor shall make his own interpretation of the data contained in said report, and the Contractor shall not be relieved of liability under the contractor for any loss sustained as a result of any variance between conditions indicated by or deduced from said report and the actual conditions encountered during the progress of the work. DUST CONTROL: The work includes dust control as required for the alleviation or prevention of any dust nuisance on or about the site or the borrow area, or off -site if caused by the Contractor's operation either during the performance of the earthwork or resulting from the conditions in which the Contractor leaves the site. The Contractor shall assume all liability, including Court costs of codefendants, for all claims related to dust or windblown materials attributable to his work. SITE PREPARATION Site preparation shall consist of site clearing and grabbing and preparations of foundation materials for receiving fill. CLEARING AND GRUBBING: The Contractor shall accept the site in this present condition and shall demolish and/or remove from the area of designated project, earthwork all structures, both surface and subsurface, trees, brush, roots, debris, organic matter, and all other matter determined by the Geotechnical Engineer to be deleterious. Such materials shall become the property of the Contractor and shall be removed from the site. Tree root systems in proposed building areas should be removed to a minimum depth of 3 feet and to such an extent which would permit removal of all roots larger than 1 inch. Tree root removed in parking areas may be limited to the upper 11/z feet of the ground surface. Backfill or tree root excavation should not be permitted until all exposed surfaces have been inspected and the Geotechnical Engineer is present for the proper control of backfill placement and compaction. Burning in areas, which are to receive fill materials, shall not be permitted. SUBGRADE PREPARATION: Surfaces to receive Structural fill shall be prepared as outlined above, excavated/scarified to a depth of 12 inches, moisture -conditioned as necessary, and compacted to 95 percent compaction. Loose and/or areas of disturbed soils shall be moisture conditioned and compacted to 95 percent compaction. All ruts, hummocks, or other uneven surface features shall be removed by surface grading prior to placement of any fill material. All areas which are to receive fill materials shall be approved by the Geotechnical Engineer prior to the placement of any of the fill material. EXCAVATION: All excavation shall be accomplished to the tolerance normally defined by the Civil Engineer as shown on the proj ect grading plans. All over excavation below the grades specified shall be backfilled at the Contractor's expense and shall be compacted in accordance with the applicable technical requirements. FILL AND BACKFILL MATERIAL: No material shall be moved or compacted without the presence of the Geotechnical Engineer. Material fi-om the required site excavation may be utilized for construction site fills provided prior approval is given by the GeotechnicaI Engineer. All materials Krazan and Associates, I na Offices Serving The Western United States �AV utilized for constructing site fills shall be free from vegetable or other deleterious matter as determined by the Geotechnical Engineer. PLACEMENT, SPREADING AND COMPACTION: The placement and spreading of approved fill materials and the processing and compaction of approved fill and native materials shall be the responsibility of the Contractor. However, compaction of fill materials by flooding, ponding, or jetting shall not be permitted unless specifically approved by local code, as well as the Geotechnical Engineer. Both cut and fill shall be surface compacted to the satisfaction of the Geotechnical Engineer prior to final acceptance. SEASONAL LIMITS: No fill material shall be placed, spread, or rolled while it is frozen or thawing or during unfavorable wet weather conditions. When the work is interrupted by heavy rains, fill operations shall not be resumed until the Geotechnical Engineer indicates that the moisture content and density of previously placed fill are as specified. Krazan and Associate% I nc. Offices Serving The Westem United States �A3 APPENDIX C PAVEMENT SPECIFICATIONS 1. DEFINITIONS — The term "pavement" shall include asphalt concrete surfacing, untreated aggregate base, and aggregate subbase. The term "subgrade" is that portion of the area on which surfacing, base, or subbase is to be placed. 2. SCOPE OF WORK — This portion of the work shall include all labor, materials, tools and equipment necessary for and reasonable incidental to the completion of the pavement shown on the plans and as herein specified, except work specifically notes as "Work Not Included." 3. PREPARATION OF THE SUBGRADE — The Contractor shall prepare the surface of the various subgrades receiving subsequent pavement courses to the lines, grades, and dimensions given on the plans. The upper 12 inches of the soil subgrade beneath the pavement section shall be compacted to a minimum compaction of 95% of maximum dry density as determined by test method ASTM D1557. The finished subgrades shall be tested and approved by the Geoteelmical Engineer prior to the placement of additional pavement of additional pavement courses. 4. AGGREGATE BASE — The aggregate base shall be spread and compacted on the prepared subgrade in conformity with the lines, grades, and dimensions shown on the plans. The aggregate base should conform to WSDOT Standard Specification for Crushed Surfacing Base Course or Top Course (Item 9-03.9(3)). The bass material shall be compacted to a minimum compaction of 95% as determined by ASTM D1557. Each layer of subbase shall be tested and approved by the Geotechnical Engineer prior to the placement of successive layers. 5. ASPHALTIC CONCRETE SURFACING — Asphaltic concrete surfacing shall consist of a mixture of mineral aggregate and paving grade asphalt, mixed at central mixing plant and spread and compacted on a prepared base in conformity with the lines, grades, and dimensions shown on the plans. The viscosity grade of the asphalt shall be AR-4000. The mineral aggregate shall be WSDOT '/2 inch Hot Mix Asphalt (HMA). The drying, proportioning, and mixing of the materials shall conform to WSDOT Specifications. The, prime coat, spreading and compacting equipment, and spreading and compacting the mixture shall conform to WSDOT Specifications, with the exception that no surface course shall be placed when the atmospheric temperature is below 50 degrees F. The surfacing shall be rolled with combination steel - wheel and pneumatic rollers, as described in WSDOT Specifications. The surface course shall be placed with an approved self-propelled mechanical spreading and finishing machine. 6. TACK COAT — The tack (mixing type asphaltic emulsion) shall conform to and be applied in accordance with the requirements of WSDOT Specifications. Krazan and Associates, I na Offices Serving The Western United States PmLi mm'"', Krazan &ASSOCIATES, INC. GEOTECHNICAL ENGINEERING • ENVIRONMENTAL ENGINEERING CONSTRUCTION TESTING & INSPECTION July 20, 2017 Krazan File Number 062-16008 Covenant Group 2044 California Avenue Corona, CA 92881 Attention: Ms. Julie A. Margetich Email: Mar etichJ acificdentalservices.corn Tel: (951) 582-5745 Reference: Geotechnical Engineering Addendum Letter Stormwater Infiltration Feasibility Proposed New Dental Office Parcel No. 415920-0715 SW Campus Drive & 11t Avenue South Federal Way, WA Dear Ms. Margetich, This letter presents our geotechnical engineering opinions regarding stormwater runoff infiltration feasibility for the proposed new dental office to be located northwest of the intersection of SW Campus Drive and 1st Avenue South in Federal Way, Washington. Introduction It is our understanding that the City of Federal Way has requested information regarding the feasibility of on -site stormwater infiltration for this project location. We previously issued a geotechnical engineering report for the site titled, "Geotechnical Engineering Investigation — Proposed New Dental Office — Parcel No. 415920-0715 — SW Campus Drive and 1st Avenue South, Federal Way, Washington 98023," dated February 15, 2017. The scope of our additional services were outlined in our "Change Order No. 1 — Geotechnical Engineering Consultation Services — Proposed New Dental Office — Parcel No. 415920-0715 — SW Campus Drive & 1st Avenue South, Federal Way, WA," dated July 20, 2017. Subsurface Conditions Our previous soil borings at the project site encountered gravel and sand fill material overlying native silt with clay soils. The gravel and sand fill was approximately 12 to 16 feet in depth at our boring locations, and interpreted to have been imported and compacted during previous earthwork construction. The native silt with clay soils were interpreted to have been deposited in an ancient lacustrine, or lake, environment. Offices Serving The Western United States 4303 —1981h Street SW, Lynnwood, WA 98036 • (425) 485-5519; Fax (425) 485-6837 A44A KRAZAN & ASSOCIATES, INC. KA Project No. 062-16008 Federal Way Dental Office Stormwater Infiltration Feasibility Letter July 20, 2017 Page No. 2 Groundwater seepage was encountered in our two soil borings from about 11 to 15 feet below the existing ground surface. Storm"'ater Infiltration Feasibility It is our opinion from a geotechnical standpoint that stormwater infiltration, including pervious pavement, is not feasible due to the presence of fill material overlying native silty and clayey soils. Fill materials can vary in texture and density, and therefore it is typically recommended that fill materials not be used as a medium for stormwater infiltration. We also referred to the "King County, Washington — Surface Water Design Manual," (KCWSWDM) (King County Department of Natural Resources and Parks, April 24, 2016), and the City of Federal Way stormwater manual titled, "Addendum to The King County Surface Water Design Manual," effective date January 8, 2017. The King County stormwater manual indicates that the bottom of iiitiltTation facilities must be in native soil (ie. see Chapter 5, Sections 5.2.4.1 and 5.2.5.1). Accordingly, stormwater infiltration is not feasible at this site due to the fill materials encountered in our previous geotechnical explorations. Also, we understand that there is a subsurface stormwater vault adjacent to the site, and infiltration of stormwater on this site could have deleterious affects on the underground structure. Limitations This letter has been prepared for the exclusive use of our client and project representatives, for the specific application to the subject site. Our conclusions are based on the limited investigation of subsurface conditions at the subject site and on our interpretation of the current conditions only. If conditions are encountered that appear to be different than those described in this report, we should be notified so that we may review and verify or modify our recommendations. This letter does not include any environmental site assessment for the presence or absence of hazardous and/or toxic materials in the soil, groundwater or atmosphere, or the presence of wetlands or other biological conditions. The information presented herein is based upon professional interpretation using standard industry practices and engineering conservatism that we consider proper for this project. It is not warranted that such information and interpretation cannot be superseded by future geotechnical developments. 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 letter 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. Krazan & Associates, Inc. Offices Serving The Western United States n 4gT KRAZAN & ASSOCIATES, INC. KA Project No. 062-16008 Federal Way Dental Office Stormwater Infiltration Feasibility Letter July 20, 2017 Page No. 3 We appreciate the opportunity to provide this service for you. If you have any questions, or if we may be of further assistance, please do not hesitate to contact our office at (253) 939-2500. Respectfully submitted, KRAZAN & ASSOCIATES, INC. 07/20/17 �4 W c SI?l 28$2 I Jeffrey 0. League Michael D. Rundquist, P.E. Jeffrey G. League, L.G. Senior Project Manager Project Geologist JGL:MDR Krazan & Associates, Inc. Offices Serving The Western United States Aqq C w f € yy m { O f 5 i3 a O _ - ^tt;�.?l:.,E. w o ti 0 'd-- �i. •p CL u.4 • ..'Cl+rlx b/RIFe: �' .. ., [� ... ,? ,n . '� E Q I x_.s. s lxta.�d 01, Al 3 i 1 It Rr ' �h•0. f>x' _ �-a-6N U Am� 4P 1731'N 47' 17 21' N 3 Soil Map —King County Area, Washington s a 5�1L� ljj�-ORA�ATMA) MAP 5500O0 55D120 550150 Fa50180 550210 3 N Map Sole: 1:1,500 if printed on A pataR (8.5' x 11 ") sty. Meters N 0 20 40 80 120 0 0 Ci0 '100 c"00 300 A Map prn)ec4pn: Web Mercator CnmerWX*%Y C5: WGS84 Edge tics: UTM pone 1ON WGSS84 usD,t Natural Resources Web Soil Survey Conservation Service National Cooperative Soil Survey P� L�b 41 17 31' N Q 47' 17 21' N 550240 55270 55m 3 'a 4/612017 Page 1 of 3 Soil Map —King County Area, Washington Map Unit Legend King County Area, Washington (WA633) Map Unit Symbol Map Unit Name Acres In AOI Percent of AOI EwC EverettAlderwood gravelly 1.2 100.0% sandy loams, 6 to 15 percent slopes Totals for Area of Interest 1.2 100.0% USDA Natural Resources Web Soil Survey +0 Conservation Service National Cooperative Soil Survey 4/6/2017 Page 3 of 3 ME gravelly coarse sand to very gravelly loamy sand. epth to the IIC horizon ranges from 18 to 36 ch es . Some areas are up to 5 percent included Aide ood so s, on the more rolling and undulating part of the andscape; some are about 5 percent the d p, sand Indianola soils; and some are up to 25 ercent Neilt Very gravelly loamy sands. Also in ded in map ng are areas where consolidated gI ial till, which a ractcristically underlies Alderw d soils, is at a pth of 5 to 15 feet. Permea lity is rapid. The effectiv noting depth is 6 inches or more. Available ater capac- ity is low. Runoff is slow, and the a sion hazard is slight, 'Phis soil - used for timber and asture and for urban developm t. Capability unit Vs-1; woodland group 3f3. sl hi sail is rot ng. nreas are 1 egular in shape, avp a 'on x surface, and range from 25 acres to yfl,,than 20 acres in size. Run- off is slow to meand t erosion hazard is slight to moderatIt Soils includedi soil in mapping make up no more than 25 pt the total acreage. Some areas are up to 5en tlderwood soils, which overlie consolidal, i till; some are up to 20 percent Neiltogra •lly loamysand; and some are about 15nt in uded areas of Everett soils where slopemore g tle than 5 percent and where they arepex tha 15 percent. This Everett ss used fo timber and pasture and for urban devent. Capa lity unit VIs-l; woodland group 3f s e .- }pis soil occurs as I g, narrow /ome , mostly long drai_nageways or a\er rt slopes en terr a benches. It is similEverett lly s y loam, 0 to 5 percent $, but in place is stonier and more grave ils eluded with this soil in mmake up re an 30 percent of the total Some a up to 10 percent Alderwood , hick i consolidated glacial till; soe to 5 the deep, sandy Indianola soiome ro10 percent Neilton very gravellmy s d;omeare about 15 percent includeas oftt soils where slopes arc less tS perc t.noff is medium to rapid, and theion haz dderate to severe. st of the acreage is used for ti, Capa- ty unit VIe-1; woodland group 3f2. Everett-Alderwood avelly sandy loams 6 to 15 ercent slo Rs A,EwL'j,--his mapping unit as about equal parts EvaTeft and Alderwood soils. The soils are rolling. Slopes are dominantly 6 to 10 percent, but range from gentle to steep. Most areas are irregular in shape and rang© from 1s to 100 acres or more in size. In areas classified as Everett soils, field examination and geologic maps indicate 16 the presence of a consolidated substratum at a depth of 7 to 20 feet. This substratum is the same mate- rial as that in the Alderwood soils. Some areas are up to 5 percent included Norma, Seattle, and Tukwila soils, all of which are poorly drained. Runoff is slow to medium, and the erosion hazard is slight to moderate. Most of the acreage is used for timber. Capabil- ity unit Vls-1; woodland group 3f3. The Indianola series .is made up of. somewhat ex ssively drained soils that formed under conifer in ndy, recessional, stratified glacial drift. T71es undulating, rolling, and humm/Fe ils ar n terra ps. Slopes are 0 to 30 percee ann 1 pxecl.p txtion is 30 to 55 inches, amean annual it temperature is about 50'e f st- free sea n is 150 to 210 days. Elr• ges from abo sea level to 1,000 feet. In a r xesentative profile, theinches is brown, rk yellowish -brown, andlive- brown loamy "ine sand. This i.s undby olive sand that ex nds to a depth of 60 or more(pl. 1, right Indianola s Is are used for timfor urban development, (InC).--This undul ing and roll g soil ]las convex slopes. It is near he edges , upland terraces. Areas range from 5 t more th 100 acres in size. Representative pr 'le of dianola loamy fine sand, 4 to 15 percent lopes in forest, 1,000 feet west and 900 feet Bout f a northeast corner of sec. 32, T. 25 N., R. 6 01--3/4 inch to 0, leaf ter. B21ir--0 to 6 inches, ow] (lOYR 4/3) loamy fine sand, brown (10 5/3 dry; massive; soft, very friable, nstick nonplastic; many roots; slight acid; c •ar, smooth boundary. 4 to 8 incho thick. B22ir--6 to 15 i es, dark ye). wish -brown (LOYR 4/4) loamy ine sand, brow (10YR 5/3) dry; massive; oft, very friable nonsticky, non- plastic- common roots; sligh acid; clear, smooth oundary. 6 to 15 ine thick. C1--15 to 3 inches, light olive-bro (2.5Y 5/4) loam fine sand, yellowish bro (IOYR 6/4) dry massive; soft, very friabl nonsticky, no lastic; common roots; slight acid; ,dual, smooth boundary. 12 to inches lick. C2- to 60 inches, olive (5Y 5/4) sand, 'ght brownish gray (2.5Y 6/2) dry; single ain; loose, nonsticky, nonplastic; few roo slightly acid. Many feet thick. There is a thin, very dark brown Al horizon t the surface in some places. The B horizon rang Nl„( b �LOOD �P�Te MAP CC bq w W wi z � 4 y� N � a $ O. W UL7 C"'H PN C�o r •--� Z ��j'"� E. Wo q�n mPal�N0. o€y�� , G J L ¢ � Li..aA 8 ? w SSE d a o � N n� LLo E `. c!}loo 00 N � -qo Hinos 3fWAV 11M ff y�RS �n >6 lu ® �d �Of N C) a CV Q x 5 0 Ao pp Q" CV) N M LEVEL 1 DOWNSTREAM ANALYSIS MAPIF 1_M. �J,!►''.y. iq ,r ` F, Alm�'+r fit;] 3;rpl ?�. r+ $4G�. S•ia+ip•1'.'� _' E bil, "d _10;_� V IF Fr .01 e �r ri. y��4 rt• *' {. 3%ilitil•T +'� !�- �i } i, [i •� ;' ti • ,tr k 1 �+'`%1.°i=.r'},. t�No""� t �I�* i R r *- 'ram r 3' �',,0 r 17,i:`(i 1 .i s Gy . tS 7.�' i CIA, _3461 3'F ti• ti +�t� Y f 4P [ i ',�! ';�.141 ` ti �" i' ' fc`. r1i� �. � : � : t' � T,r. "t.y�z.[7 , . � } �:t4G? ;i 'y� �. � • r R. - � �4 � e . �45y'�+� �� , �'� • `;� sc '-�'l (a � • r�� 7�, - � + �'� "� - � � ' . � � t i „ij,`.�.1 � .� •. F �.'� .._�'•� a� :r v ► i >. tti ; �"- �' �' ` r� rye- t.• } . ' 1' + ail i J '� a• - ie At ��' •�JZM1•l.;•i:�.�: a �._ • 4711 �� lt[i' �ps A [ • �k elii5 y 1' I:47 4 .ter° ` •L ~ Y f{y s "� 31- ; 61 �+ r j ■ !s y:/��, t �R� i ' '' rJ. wits/fIF T+i. �•Cx �i�Ilf �'�-. 1 r �ir- S a•� T'�! ! .'�• . N ;l;t } ' •"3 }'�1:J�; �9fr - — �, _ PPam+ -„sue �' C '' a r .0 ' { 3"T80 i t {' �• .!{I 1 dr` b{ 4i+'�°�iG�{x w .r.; i. i TP.. [ , t V�••r w; c I. '�, ��, r+r•r. � +� ]',i Sr ��,�n �( ��y � e` _ � s - ti .J �:.ti, � y� V Imo• i'Vpvr, . 11 .n �-� - - 1„� Y ^r.410 S - ' , .' �' a ` •F.` y 1' �1. i Tfi'� i'�f 1'i , 1ZOo��T i+�h ,•� t .1� 'R,�i� •��- �p��11ri 1' 41 .. !��.�jg �j ��, �} filll-i r„ ` � *�T -� 'r >r � ••� � ..1�'_' � '`- I'�` .t�-a �� •� �7' :! �.,y� - y � .�� PU �x•.� QP r �der ,a. _ .� :,Fi r� - '- •' . • f��. T'Ifl].�F- 1]/ +]]3 t'C+� 15 S �S <<. ,� -" { "1 ., KN _ rr i]• 1:.;* f�' y.�, x _ -Vi. �� •�A r - - it - t y •r ` 'i" - .�"rF�+rjf .�. �r_ �+ : i �i+ �� :rI � !• �r �•� _ � � �` � �� T ■' • A� 4 I r rand -' �,',�l i Jr— ,� x * , - s yam, 1= 5 pall, kr A ' ..,r�• t i= }, ]ir Mk 41 f f - P The information included on this map has been compiled by King County staff from a variety of sources and is subject to change without notice. King County Date: 4/6/2017 LQ King County makes no representations orwarranties, express or implied: as to accuracy, completeness, timeliness, or rights to the use ofsuch information. This document is not intended for use as a survey product. King County shall not be liable for any general, special, indirect, incidental, or consequential damages including, but not limited to, lost revenues or lost profits resulting from the use or misuse of the information contained on this map. Any sale of this map or information on this map is prohibited except by written permission of King County. Notes: GIS CENTER `5() q12, CITY OF Federal Public Works Department AGREEMENT & PERFORMANCE/ MAINTENANCE BOND INFORMATION SHEET PROJECT INFORMATION Project dame: 1 2reA L UJAY C-&V1V .Er?-r—T-PL Lar-b Bond No.: Address: 1(94 C-W FE26?-Atr WA-r L/+1A 92,07* (Street) (City) (State) (ZIP) Development Review Engineer: ,4ww VOL.36E Permit No.: I�'�a58W8"oo'GCY Description of Work: The Principal has entered into an Agreement with the City for the civil infrastructure required as part of the subject development which includes: O Curb & Gutter O Sidewalk Pif Erosion Control O Streetlights O Utility Work O Signalization O Channelization O Drainage 17 Planter Strip with Street Trees O Paving Other Required Information: A Full Legal Description )d Abbreviated Legal Description 0 Parcel Number(s) BOND PRINCIPAL INFORMATION Person(s) entering into the agreement with the City. Bond Principal: Federal Way Covenant Group LLC and EP Federal Way LLC, as tenant in common State of Incorporation: Nevada (Ifappllcable) Nature of Principal's Entity: Limited Liability Comany (i.e. Corporation, General Partnership, Limited Partnership, Individual, etc.) Individual Signing on Behalf of Principal: i. Stephen E. Thorne, IV Member of Federal Way Covenant Group LLC (Name) (Title) 2. Bruce M. Kahl Manager of EP Federal Way LLC Mailing Address: 2460 Paseo Verde Parkway, Suite 145, Henderson, NV 89074 (Street) (City) (State) (ZIP) Phone: 714-845-8646 Fax Number: O Attach Signature Authority' (except for Individual Entity) ' This is an official document that has been submitted to the State showing who has authority to sign legal documents on behalf of the company. (i.e. Corporate Resolution, Company By -Laws, or State License showing Corporate Officers) Agreement & Performance/Maintenance Bond Information Sheet Rev. 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II o o a; § K f . ,- - ai- ".= i 11r S W CAMPUS ;p"s 11 r+1 Li '.1.-ccti�•. - f� R . _' _ � � 1I f II • NOTFs /_— � U 'y.. ... - AM LT WCR AArFDN FOR 17f VAULT - •- .... ti• I AND VAULT PPE IMMM %1J_ BE W=DED J N 11-E IECi 8 MWff9_ W _ f Z� Z N [ UM V4- rk � �� ll _ - � 1• _F T i Ij • \ l � 1 i (rJ�� C �f ��d w u T 1�BID!w $�jq)R{waT�DR54taCE _AwA93T-_.. ¢45 SAB:p S� _ 1 Y A Sa.. v9 ■ (-PVXrS %7 O S MCT PRCPERM I i I PnNT NQ, mmo-o00O u ■ f it CCiY OF FEDFAAL WAY r p� Ell �C AS —BUILT 5 APPROVED ' OQ DATE' V � 1 .r ;SD:`ak•J1�512T\e..7:n n:G%:?:s,i ��c Ce1e`m-_ OI�C3; =:r,1 I�:GD C-ai-. .-_u _C. ar-is Larson & Associates surveyors, engineers & planners 9027 Pacific Avenue, Suite 4 Tacoma, WA 98444-6247 FEDERAL WAY COMMERCIAL (LOT B) LIMINARY CHNICAL INFORMATION REPORT WITH LEVEL 1 DOWNSTREAM ANALYSIS PROPONENT: Covenant Group 2044 California Ave. Corona, CA. 92881 Contact: Julie Margetich Ph: (951) 582-5745 PREPARED BY: Larson & Associates surveyors, engineers & planners 9027 Pacific Avenue, Suite 4 Tacoma, WA 98444-6247 (253) 474-3404 September 11, 2017 T A R � L-'_ E 0j F CON TV " * E N, lif, S PROJECTENGINEER'S CERTIFICATION......................................................................................................... I PRELIMINARY T.I.R. PROJECTOVERVIEW.............................................................................................................................................. 2 EXISTINGSITE CONDITIONS SUMMARY................................................................................................................. 2 CORE REQUIREMENT #I :DISCHARGE AT THE NATURAL LOCATION.......................................................................... 2 CORE REQUIREMENT #2: CONDITIONS AND REQUIREMENTS SUMMARY.................................................................. 3 COREREQUIREMENT #3: FLOW CONTROL............................................................................................................... 3 CORE REQUIREMENT #4:CONVEYANCE SYSTEM...................................................................................................... 3 CORE REQUIREMENT #5: CONSTRUCTION STORMWATER POLLUTION PREVENTION PLAN ..................................... 4-9 CORE REQUIREMENT #6: MAINTENANCE AND OPERATION..................................................................................... 9 CORE REQUIREM EN, `+7:FINANCIAL GUARANTEES AND LIABILITY.......................................................................... 9 CORE REQUIItEMENT#8: WATER QUALITY...................................................................................... ...................... 9 CORE REQUIRE'vIE+IT#9:FLOW CONTROL BMPS................................................................................... ................9-10 SPECIAL REQUIREMENT # 1: OTHER ADOPTED AREA SPECIFIC REQUIREMENTS....................................................... 10 SPECIAL REQUIREMENT #2: FLOOD HAZARD AREA DELINEATION.......................................................................... 10 SPECIAL REQUIREMENT #3: FLOOD PROTECTION FACILITIES ......... :........................................................................ 10 SPECIAL REQUIREMENT #4: SOURCE CONTROL......................................................................................................10 SPECIALREQUIREMENT #5: OIL CONTROL............................................................................................................. 10 PROJECTAREA TABLES:.........................................................................................................................................11 CONVEYANCE SYSTEM CALCULATIONS.................................................................................................12-16 CONTECH FILTERRA WWHM SIZING CALCULATION..............:..........................................................17-18 LEVEL 1 AND LEVEL 2 FLOW CONTROL CALCULATIONS ................................................ ................. 19-27 APPENDIX......................................................................................................................................................... Al-A7 DEPARTMENT OF ECOLOGY G.U.L.D. LETTER FOR CONTECH FILTERRA VAULT .................... Al-A9 GEOTECEMCAL ENGINEERING STUDY PREPARED BY KRAZAN......................................................... A10-A44 VICINITYMAP.................................................................................................................................................. A45 SCSSOILS INFORMATION.................................................................................................I.....I...........A46-A48 FLOODINSURANCE RATE MAP................................................................................................................. A49 LEVEL 1 DOWNSTREAM ANAYLSIS MAP.........................................................................................A50-A51 PRE -DEVELOPED AND DEVELOPED BASIN MAP................................................................................... A52 PROJE ,CT ENG-N, FEETWS'. C MWITICARON I hereby state that this Preliminary Technical Information Report for Federal Way_ ,Commercial of B has been prepared by me or under my supervision and meets the standard of care and expertise which is usual and customary in this community for professional engineers. I understand that the City of Federal Way does not and will not assume liability for the sufficiency, suitability, or performance of pollution prevention facilities prepared by me. P R L -1, -F Mm, RRY_3 T I R SECTION 1- PROJECT OVERVIEW This preliminary technical information report has been prepared to obtain clearing and grading and site development permits for the proposed construction of commercial building which will contain a dentist office and retail space located in a portion of Sec.1g,TWN. 21N, RNG. 4E Willamette Meridian, Federal Way, King County, Washington. The site is immediately adjacent to SW Campus Drive to the west and lst Ave. S. to the east. The project site consists of approximately 1.5 acres and is located on parcel number 4159200715. The proposed building will be approximately 5,000 SF. The proposed building will be constructed over existing parking lot area that will be removed. There will be minimal cuts/fills (<500CY's) anticipated as this lot is essentially building pad ready with minimal "fill" to construct final pad grade and "drive-thru" isle. Proposed impervious surface associated with building footprint will be tightlined to the Storm Vault for detention, which is downstream of treatment device, prior to being meter released to the existing storm system located at the southwest corner of the property. Roof stormwater is deemed "clean" per Department of Ecology standards and therefore can bypass the Contech Filterra treatment vault. The stormwater from the impervious "drive-thru" isle will be collected via gutter flowline and routed to and through the proposed Contech Filters treatment vault and then to the Storm Vault for detention prior to being meter released to the existing storm system located at the southwest corner of the property. We are proposing grind and overlay of the existing drive isle and parking lot east of the proposed building. Due to this just being a maintenance act, this area will not be subject to quality or quantity control. This project is within the Federal Way Community Planning area and is within the Puget Sound Drainage Basin. FXITINO CONDITION SUMMARY The parcel contains existing asphalt parking and drive isle area with perimeter concrete curbing which will be removed to allow for proposed building construction. There are also existing stormwater features and structures located on this parcel which will remain and be protected including an underground stormwater "wet vault", underground oil/water separator vault, "grassed" bioswale and existing retaining wall which are located outside and to the west of the proposed building pad area within an existing storm easement. CORE REQUIREMENT #14 DISCHARGE AT THE NATURAL LOCATION The stormwater generated by this proposal will be collected in associated catchbasins and discharged in the natural location to existing 30" diameter storm pipe at the southwest portion of the project along SW Campus Drive. The proposed development of this parcel will not alter the existing drainage patterns of the basin nor will it direct stormwater flows offsite across property boundaries to adjacent properties. CORE REQUIREMENT #2: OFF -SITE ANALYSIS Please refer to Section 3 of the 1" Avenue Basin. Pond Technical Information Report prepared by Brown & Caldwell for the downstream analysis portion of this project. A detailed analysis was previously performed qualifying the existing impervious coverage and associated runoff within the offsite drainage system. Furthermore, this proposal will be reducing contributing total impervious area runoff and pollution generating impervious area runoff from the current condition as a parking lot. LEVEL 1 DOWNSTREAM ANALYSIS DISCUSSION: Stormwater discharge from the site will enter the existing SDMH located in southwest comer of the property prior to being discharged through a ±200 LF - 30" diam. culvert running under SW Campus Drive which then appears to release flows to an unnamed stream. From this point flows appear to be routed within the stream channel south — southeast an additional f1200 feet to 1t Ave. S. culvert crossing where upon this required qualitative'/ mile downstream analysis has been terminated. From vision inspection there did not appear to be any capacity issues or maintenance concerns with the existing storm system at our project frontage releasing flows across SW Campus Drive. See the Appendix of this report for a Level 1 Downstream Analysis map for additional information. CORE REQUIREM[ENT #3: FLOW CONTROL This project is located within the 1t Avenue South basin regional detention pond basin. The stormwater detention volume for this parcel was included in the previous analysis and design of the existing I" Avenue South basin pond. See the TIR report previously prepared by Brown & Caldwell dated November 6, 1997 for additional information associated with the analysis and design. After discussion with the City of Federal Way on the understanding of what flow control volume "credit" this project would receive from the previously constructed 1" Ave. S. Basin pond it was determined that our parcel currently meets Level 1 flow control with existing pond consideration. The city then requested that we size a "hypothetical" flow control facility to meet Level 1 flow control requirements and again to size a flow control facility to meet Level 2 flow control meeting the requirements of the 2016 King County Stormwater manual. It was then understood that we would simply be required to provide the deficit in volume between these two levels of analysis. The Level 1 flow control detention facility was designed to meet Level 1 flow control to today's standards matching the existing site conditions 2 and 10 year peak flows. Then we sized a "new" detention facility meeting Level 2 flow control to today's standards applying historic site conditions which match historic durations for 50% of the 2 year through 50 year peak and matches 2 and 10 year peaks. The required volume difference between Level 1 and Level 2 flow control requirements has been determined to be 2,730 CF at detention facility riser crest elevation. We have now proposed an underground detention vault facility achieving this volume of 2,730 CF for this project on the south side of the proposed building within the landscape area to meet flow control facility requirements. The proposed vault will receive tighlined flows from proposed building roof drain connection and runoff associated with the proposed drive thru lane and dumpster pad area. Stormwater will then be metered back out to the existing storm system located in the southwest corner of the property meeting required release rates. CORE REQUIREMENT #4: CONVEYANCE SYSTEM Stormwater runoff generated from this proposal associated with existing and new pollution generating impervious surfaces on this parcel will be collected by associated catchbasins and routed to and through a treatment vault system and storm vault facility via 6"-10" storm pipe discharging flows to the existing storm system at the southwest corner of the property. A 6" roof drain tightline pipe will be provided for connection and routing of roof surface water around the treatment system and to the storm vault. See attached conveyance calculations in the Appendix of this report for pipe size adequacy evaluation. CORE REQUIREMENT #S: CONSTRUCTION STORMWATER POLLUTION PREVENTION Stormwater pollution prevention will be maintained during the construction of this site by incorporating standard erosion control methods such as a temporary construction entrance and mirafi siltation fences. The following devices will be used to trap sediment from the cleared areas and prevent it from leaving the site. Mirafi silt fences will be installed along the perimeter to stop any sediment runoff from exiting the project limits. Inlet sediment protection will also be installed in all existing and proposed catchbasin locations which have inlet grates to trap sediment and prevent it from entering the storm system. The following general Washington State Elements shall be upheld at all tunes during the construction process. 1). Mark Clearing Limits Prior to beginning land disturbing activities; including clearing and grading, all clearing limits shall be clearly marked in the field and trees that are to be preserved shall be clearly marked within the construction area. These shall be marked, both in the field and on the plans, to prevent damage and offsite impacts. 2) Cover Measures This project is currently stabilized with existing impervious surfaces associated with parking lot areas and limits of work will be minimal to construct building pad over existing parking lot. Once asphalt parking lot demolition occurs the building pad will be constructed for building and drive isle and associated landscape areas will be seeded/sodded and/or planted to stabilize exposed pervious areas. 3) Perimeter Protection Prior to demolition activities commencing onsite perimeter silt fence shall be installed around the proposed disturbance area to protect again possible sedimentation offsite. Li 4) Traffic Area Stabilization It is not anticipated that this proposal will require specific stabilization of traffic areas due to lunited scope to construct new storm conveyance system, side sewer and water service on the parcel. 5) Sediment Retention Again, prior to clearing/grading and/or demolition activities commencing onsite perimeter silt fence shall be installed around the proposed disturbance area to protect again possible sedimentation offsite and these measures shall be maintained regularly throughout construction. 6) Surface Water Collection Surface water collection will be at existing and proposed catchbasin locations which will be provided with inlet sediment control "socks" to trap sediment and prevent it from entering the storm system. 7) Dewatering Control Due to the size and scope of the this project to construct a commercial building at an existing parking lot location we do not anticipate dewatering measures being necessary for this project. 8) Dust Control Again, due to the size and scope of the this project to construct a commercial building at an existing parking lot location we do not anticipate dust control being a concern for this proj ect. 9) Flow Control Flow control will be achieved within existing and proposed catchbasin locations which will be provided with inlet sediment control "socks" to trap sediment and prevent it from entering the storm system. 10) Control Pollutants Pollutant Control will be achieved within existing and proposed catchbasin locations which will be provided with inlet sediment control "socks" to trap sediment and prevent it from entering the storm system. There will also be onsite perimeter silt fence installed around the proposed disturbance area to protect again possible sedimentation offsite and these measures shall be maintained regularly throughout construction. 11) Protect Existing and Proposed Flow Control BSMPs The existing and proposed storm system onsite will be protected throughout construction with proposed inlet sediment protection devices (ie silt socks) at catchbasin inlet grate locations. The existing storm system on the parcel will be field located prior to construction so it is fully understood where the facilities are located so the contractor can then incorporate necessary protection of said facilities. 9 12) Maintain BMPs All temporary and permanent erosion and sediment control BMPs shall be maintained and repaired as needed to assure continued performance of their intended function in accordance with BMP specifications. All temporary erosion and sediment control BMPs shall be removed within 30 days after final site stabilization is achieved or after the temporary BMPs are no longer needed. 13) Manage the Project • Inspection and Monitoring All BMPs shall be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections and monitoring shall be conducted in accordance with S4. • Maintaining an Updated Construction SWPPP The SWPPP shall be maintained, updated, and implemented in accordance with Conditions S3, S4 and S9. Monitoring Requirements The primary monitoring requirements are summarized in Table 3 (below): Table 3. Summary of 1Vlnrcitoring Re uirements Size of Soils Disturbance Weekly Weekly Weekly Weekly Site Sampling Sampling w/ pH Inspections w/ Transparency sampling3 Turbidity Tube Meter Sites which disturb less Required Not Not Required Not than 1 acre Required Required Sites which disturb 1 acre Sampling Required — either or more, but less than 5 Required method Required acres Sites which disturb 5 acres Required Required Not S T Required_ Required or more 1 Additional monitoring requirements may apply for: 1) discharges to 303(d) listed waterbodies and waterbodies with applicable TMDLs for turbidity, fine sediment, high pH, or phosphorus — see Condition S8; and 2) sites required to perform additional monitoring by Ecology order — see Condition G13. 2 Soil disturbance is calculated by adding together all areas affected by 101 construction activity. Construction Activity means clearing, grading, excavation, and any other activity which disturbs the surface of the land, including ingress/egress from the site. 3 Beginning October 1, 2006, if construction activity involves significant concrete work or the use of engineered soils, and stormwater from the affected area drains to a stormwater collection system or other surface water, the Permittee shall conduct pH sampling in accordance with Condition S4.D. 4 Beginning October 1, 2008, sites with one or more acres, but less than 5 acres of soil disturbance, shall conduct turbidity or transparency sampling in accordance with Condition S4.C. 5 Beginning October 1, 2006, sites greater than or equal to 5 acres of soil disturbance shall conduct turbidity sampling using a turbidity meter in accordance with Condition S4.C. A. Site !:Rg Book The Permittee shall maintain a site log book that contains a record of the implementation of the S WPPP and other permit requirements including the installation and maintenance of BMPs, site inspections, and stormwater monitoring. B. Site Inspections 1. Site inspections shall include all areas disturbed by construction activities, all BMPs, and all stormwater discharge points. Stormwater shall be visually examined for the presence of suspended sediment, turbidity, discoloration, and oil sheen. Inspectors shall evaluate the effectiveness of BMPs and determine if it is necessary to install, maintain, or repair BMPs to improve the quality of stormwater discharges. Based on the results of the inspection, the Permittee shall correct the problems identified as follows: a. Review the SWPPP for compliance with Condition S9 and make appropriate revisions within 7 days of the inspection; and b. Fully implement and maintain appropriate source control and/or treatment BMPs as soon as possible, but no later than 10 days of the inspection; and c. Document BMP implementation and maintenance in the site log book. 2. The site inspections shall be conducted at least once every calendar week and within 24 hours of any discharge from the site. The inspection frequency for temporarily stabilized, inactive sites may be reduced to once every calendar month. 3. Site inspections shall be conducted by a person who is knowledgeable in the principles and practices of erosion and sediment control. The inspector shall have the skills to: a. Assess the site conditions and construction activities that could impact the quality of stormwater, and b. Assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. 4. Beginning October 1, 2006, construction sites one acre or larger that discharge stormwater to surface waters of the state, shall have site inspections conducted by a Certified Erosion and Sediment Control Lead (CESCL). The CESCL shall be identified in the SWPPP and shall be present on -site or on -call at all tunes. Certification shall be obtained through an approved erosion and sediment control training program that meets the minimum training standards established by Ecology (see BMP C160 in the Manual). 5. The inspector shall summarize the results of each inspection in an inspection report or checklist and be entered into, or attached to, the site log book. At a minimum, each inspection report or checklist shall include: a. Inspection date and time. b. Weather information; general conditions during inspection and approximate amount of precipitation since the last inspection, and within the last 24 hours. c. A summary or list of all BMPs which have been implemented, including observations of all erosion/sediment control structures or practices. d. The following shall be noted: locations of BMPs inspected, ii. locations of BMPs that need maintenance, iii. the reason maintenance is needed, 0 • iv. locations of BMPs that failed to operate as designed or intended, and v. locations where additional or different BMPs are needed, and the reason(s) why. e. A description of stormwater discharged from the site. The inspector shall note the presence of suspended sediment, turbid water, discoloration, and/or oil sheen, as applicable. f. Any water quality monitoring performed during inspection. g. General comments and notes, including a brief description of any BMP repairs, maintenance or installations made as a result of the inspection. h. A statement that, in the judgment of the person conducting the site inspection, the site is either in compliance or out of compliance with the terms and conditions of the SWPPP and the permit. If the site inspection indicates that the site is out of compliance, the inspection report shall include a summary of the remedial actions required to bring the site back into compliance, as well as a schedule of implementation. i. Name, title, and signature of the person conducting site inspection; and the following statement: "I certify that this report is true, accurate, and complete, to the best of my knowledge and belief'. CORE REQUIREMENT #6.- MAINTENANCE AND, OPERATION A maintenance and operation manual will be developed during the final engineering stage of this project. CORE REQUIREMENT #7: PIN'ANCL L GUARANTEES AND LIABIILITY This will be addressed during final engineering plan review and construction. CORE REQUIREMENT #S: WATER QUALITY Formal water quality treatment has been provided for this project utilizing a Contech Filterra treatment vault which will provide the necessary enhanced "basic" water quality treatment necessary per Department of Ecology and the City of Federal Way requirements. The proposed Contech Filterra treatment vault will also provide oil/water separation of stormwater which the City of Federal Way has informed us will be required due to the site's anticipated traffic volume. See the Department of Ecology Letter located in the Appendix of this report describing the General Use Level Designation (GULD) W issued by the Department of Ecology for the Contech Filterra treatment system to provide enhanced "basic" treatment of stormwater. CORE REQUIREMENT #9: FLOW CONTROL BMPS Regarding flow control BMP implementation for this project it has been deemed infeasible to propose any form of infiltration BMP and/or full dispersion/bioretention due property size, limited onsite pervious surface area for "dispersion" of stormwater and due to onsite soil conditions as specified in the geotechnical infiltration evaluation letter prepared by Krazan located in the Appendix of this report. We have, however, proposed soil amendment of all disturbed pervious surfaces/landscape areas associated with this project meeting 2016 King County stormwater manual requirements and soil amendment criteria. SPECIAL REQUIREMENT #1: OTHER ADOPTED AREA SPECIFIC REQUIREMENTS There are no additional adopted area specific requirements that we are aware of that must be adhered to for this development proposal. SPECIAL REQUIRENIE, NT ##2: FLOOD, HAZARD AREA DELINEATION The proposed project does not contain or abut a stream, lake, wetland or closed depression that would require such a study to be performed therefore this does not apply to this project. SPECIAL REQUY.REAJENT #3: FLOOD PROTECTION FACILITIES This project does not contain or abut a stream therefore this special requirement does not apply to this project. SPECIAL REQUIREMENT #4: SOURCE CONTROL A source control plan will be developed during the final engineering stage of this project. SPECIAL REQUIREMENT ##5: OIL CONTROL The proposed Contech Filterra treatment vault will also provide oil/water separation of stormwater which the City of Federal Way has informed us will. be required due to the site's anticipated traffic volume. See the Department of Ecology Letter located in the Appendix of this report describing the General Use Level Designation (GULD) issued by the Department of Ecology for the Contech Filterra treatment system to provide oil/water separation. "FEDERAL WAY COMMERCIAL (LOT B)" PROJECT AREA TABLES: ONSITE EXISTING CONDITIONS TABLE: TOTAL AREA=1.157 ACRES PERVIOUS AREA= 0.422 ACRES IMPERVIOUS AREA (EXISTING PARKING LOT) = 0.735 ACRES EX. PARKING LOT & CURBING (TO BE REMOVED) = 0.275 ACRES EX. PARKING LOT & CURBING (TO REMAIN) = 0.244 ACRES L EX. SIDEWALK (TO BE REMOVED) = 0.019 ACRES EX. SIDEWALK (TO REMAIN) = 0.035 ACRES EX. DRIVE ISLE & CURB (TO REMAIN) = 0.162 ACRES ONSITE PREDEVELOPED AREA TABLE ROUTED TO DETENTION FACILITY TOTAL AREA = 0.294 ACRES PERVIOUS AREA = 0.294 ACRES (MODELED AS TILL FOREST) ONSITE DEVELOPED AREA TABLE ROUTED TO DETENTION FACILITY TOTAL AREA = 0.294 ACRES PERVIOUS AREA = 0.034 ACRES IMPERVIOUS AREA = 0.260 ACRES PROPOSED BUILDING ROOF AREA = 0.118 ACRES PROPOSED DRIVE THRU ISLE & CURB = 0.093 ACRES PROPOSED SIDEWALK = 0.040 ACRES PROPOSED DUMPSTER PAD & CURB = 0.009 ACRES DEVELOPED AREA TRIBUTARY TO "FILTERRA" STORMWATER TREATMENT VAULT TOTAL AREA = 0.142 ACRES IMPERVIOUS AREA = 0.142 ACRES PROPOSED DRIVE THRU ISLE & CURB = 0.093 ACRES PROPOSED CONC. SIDEWALK = 0.040 ACRES PROPOSED DUMPSTER PAD & CURB = 0.009 ACRES. 1k CONVEYANCE SYSTEM CALCULATIONS a (,0MVeVA-NU� S�s�� tm_(l MGS FLOOD PROJECT REPORT Program Version: MGSFIood 4.41 Program License Number: 200810005 Project Simulation Performed on: 08122/2017 3:05 PM Report Generation Date: 08122/20/7 3:06 PM Input File Name Project Name: Analysis Title: Comments: Conveyance Calc.,fld Federal Way Commercial (Lot B) Conveyance Calc. Computational Time Step (Minutes): PRECIPITATION INPUT Extended Precipitation Time Series Selected Climatic Region Number: 0 Full Period of Record Available used for Routing Precipitation Station : 95004005 Puget East40 in_5min 10/01/1939-10/01/2097 Evaporation Station 961040 Puget East 40 in MAP ,Evaporation Scale Factor,.;_ 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** *************** Default HSPF Parameters Used (Not Modified by User) ********************** WATERSHED DEFINITION PredevelopmentlPost Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) . 0.294 0.294 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.294 0.294 PREDEVELOPED Number of Subbasins: 1 --------- Subbasin : Subbasin 1---------- ------- Area (Acres) -------- Till Forest 0.294 Subbasin Total 0.294 __-------- _--------- SCENARIO: POSTDEVELOPED Number of Subbasins: 1 -------- Subbasin: Subbasin 1 -----Area (Acres) Till Pasture 0.034 Impervious 0.260 Subbasin Total 0.294 ************************* LINK DATA ******** k3 --------------------SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA *.***********.*****►,***.**** ----------------------SCENARIO: POSTDEVELOPED Number of Links: 0 **********************FLOOD FREQUENCY AND DURATION STATISTICS***"*************** ---------------------SCENARIO: PREDEVELOPED Number of Subbasins: 1 Number of Links: 0 --- ---------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 0 ***********Groundwater Recharge Summary Recharge is computed as input to Perind Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin; Subbasin 1 50.976 Total: 50.976 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 6.027 Total: 6.027 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: D.323 ac-ftlyear, Post Developed: 0.038 ac ftfyear ***********Water Quality Facility Data ************* -------------------SCENARIO: PREDEVELOPED Number of Links: 0 ---------------------SCENARIO: POSTDEVELOPED Number of Links: 0 ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Subbasin: Subbasin 1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Disciharge (cfs) Tr (Years) Discharge (cfs) 1N 2-Year 6.242E-03 2-Year 7.334E-02 5-Year 3.065E-02 5-Year 9.389E-02 10-Year 1.326E-02 10-Year 0.106 25-Year 1.710E-02 25-Year 0.123 50-Year 2.059E-02 50-Year 100-Year 0.137 0.15544 ViF D "CO 100-Year 2.472E-02 200-Year 3.313E-02 200-Year 0.167 ww Record too Short to Compute Peak Discharge for These Recurrence Intervals 51-m Vvts CsEE %wv 54Et�,) %S Worksheet Worksheet for Circular Channel Project Description Worksheet 6" Conveyance Flow Element Circular Chann( Method Manning's Forrr Solve For Channel Depth Input Data Mannings Coeffic).010 Slope 0.50 % Diameter 6 in Discharge 0.16 cfs 100 SIR FLOW CSEs QREV1005 StkEET, Results Depth 0.19 ft Flow Area 0.1 ftz Wetted Perime 0.66 ft Top Width 0.48 ft Critical Depth 0.20 ft Percent Full 37.6 % Critical Slope 0.43 % Velocity 2.30 fUs Velocity Head 0.08 ft Specific Energ; 0.27 ft Froude Numbe 1.09 Maximum Disc 0.55 cfs Discharge Full 0.52 cfs Slope Full 0.05 % Flow Type supercritical & D.5p' al( - Project Engineer: Jeff Cederholm federal way commercial lot conveyance calc.fm2 Larson & Associates FlowMaster v6.1 [614k] 06/22/17 03:58:17 PM (D Haeslad Methods, Inc. 37 Brookside Road Waterbury, CT 06708 USA (203) 755-1666 Page 1 of 1 16 STORM FILTER MANHOLE SIZING CALCULATIONS V1 LC)�JTECA4 S rztti� 1 RTA E)j Gq-� 1Z7 �AUL l General Sizing Guidelines Based on the Western Washington Hydrology Model (WWHM L E njh.,nr ndl-, Hydraulic Conductivity: 1551Pbosnhorous Oil Grease :35.46 in/hr Metals 24.82 in/hr 70.92 in/hr VANCpLIVER 'Vancouver NNE rain gauge precip factor =1.110 Size Acres Treated Acres Treated -Acres Treated 4x4 0.349 0.187 - 0.136 4x6 & 6x4 0.528 0.279 0.202 4x8 & 8x4 0.705 0.372 0.269 6x6 0,794 0.419 0.303 6x8 & 8x6 1.063 0.561 0.404 6x10 & 106 1.332 0.702 0.507 6x12 & 12x6 1.615 0,844.: 0.609: TACOMA 3S in CENTRAL rain gauge Precip factor =1 - note:1901-2059 (yr] Size Acres Treated Acres Treated:- :-.Acres Treated 4x4 0.421 .0.219 0.159 46 & 6x4 0.633 0.325 0.234 J 4x8 & 8x4 0.945 0.433 0.31 6x6 0.952 0.487 0,349 6x8 & 8x6 1,272 0.651 0.465 6x10 & 10x6 1 1.594: 0.814 0.582 - 6x12 & 12x6 1 1.925 0.981. 0.701 EVERETT Everett rain gage ,precip factor =1 Size Acres Treated Acres Treated Acres Treated 44 :0.391 0.206 0.151 46 & 6x4 0.589 0.309 0.223 4x8 & 8x4 0.795 0.413 0.297 6x6 0.886 0.469 0.335 6x8 & 8x6 1.185 0.619 0.447 6x10 & 10x6 1.485 0.774 0.558 6x12 & 12x6 1.805 0.933 0.671 :SEATTLE -Seatac rain gauge precip factor = 1 Acres Treated Acres Treated Acres Treated 4x 0.384 '0.203 0.1" 4x6 & 6x4 0.578 0.303 0.219 4x8 & 8x4 0.771 0.403 0.29 6x6 0.871 0.454 0.327 6x8 & 8x6 1.165 0.607 0.437 6x10 & 1Dx 3 1.461 0.76 0.547 6x12 & 12x6 1.787 0314 0.657 Notes: 1. All treatment areas are based on 100% impervious contributing drainage area. 2. Filterra size assumes offline configuration and 21" of media. 3. For sizing in other areas, contact your Contech Engineered Solutions 5tormwater Design Engineer 4. General Guidelines Only. Each site is unique and requires sizing per the DOE GUILD Approval. C4' 9"F,HTECH' ENGINEERED SOLUTIONS 4- wo- hewn u.t4z k. . cofvvrt" ... 'b F;1iret�, LEVEL 1 AND LEVEL 2 FLOW CONTROL CALCULATIONS 1.1 l.F,VE L 1 FwQ CONTR.o'L FRI-1 L%T I MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.41 Program License Number: 200810005 Project Simulation Performed on: 08/22/2017 3:02 PM Report Generation Date: 08/22/2017 3:03 PM Input File Name: Project Name: Analysis Title: Comments: Detention Vault Sizing (Level 1 Flow Control).fld Federal Way Commercial (Lot B) Treatment Vault Sizing Computational Time Step (Minutes) PRECIPITATION INPUT .N Extended Precipitation Time Series Selected Climatic Region Number: 0 Full Period of Record Available used for Routing Precipitation Station: 96004005 Puget East 40 in_5min 10/0111939-10/0112097 Evaporation Station 961040 Puget East 40 in MAP Evaporation Scale Factor 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default ********** Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION Prod evelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.294 0.294 Area of Links that Include Precip/Evap (acres) 0.000 0,000 Total (acres) 0.294 0.294 ---- _---------------- SCENARIO: PREDEVELOPED Number of Subbasins: 1 ---------- Subbasin : Subbasin 1--------- -------Area (Acres) ------- Till Forest 0.294 Subbasin Total 0.294 ----------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 ---------- Subbasin: Subbasin 1 ------Area (Acres) Till Pasture 0.034 Impervious 0.260 Subbasin Total 0.294 ************************* LINK DATA 2,0 -__---- _----------- SCENARIO: PREDEVELOPED Number of Links: 0 ************************* LINK DATA ******************************* ___-__-----_ SCENARIO: POSTDEVELOPED Number of Links: 1 Link Name: New Structure Lnk1 Link Type: Structure Downstream Link: None Prismatic Pond Option Used Pond Floor Elevation (ft) Riser Crest Elevation (ft) Max Pond Elevation (ft) Storage Depth (ft) Pond Bottom Length (ft) Pond Bottom Width (ft) Pond Side Slopes (ftlft) Bottom Area (sq-ft) Area at Riser Crest El (sq-ft) (acres) Volume at Riser Crest (cu-ft) (ac-ft) Area at Max Elevation (sq-ft) (acres) Vol at Max Elevation (cu-ft) (ac-ft) 100.50 : 107.50 108.00 7.00 105.0 13.0 L1= 0.00 1365, 1,365. 0.031 9,555. 0.219 1365. 0,031 10,511. 0.241 L2= 0.00 W1= 0.00 W2= 0.00 Massmann Infiltration Option Used Hydraulic Conductivity (inlhr) : 0,00 : 100.00 Depth to Water Table (ft) :Low Bio-Fouling Potential Maintenance ;Average or Setter Riser Geometry ; Riser Structure Type ;18ar 1 Circular Riser Diameter (in) : .00 00 Comrraon Length (ft) : 107.50 ft Riser Crest Elevation Hydraulic Structure Geometry Number of Devices: 2 ---Device Number Device Type Control Elevation (ft) Diameter (in) Orientation Elbow --- Device Number Device Type Control Elevation (ft) Length (in) Height (in) Orientation Elbow Circular Orifice 100.50 0.25 Horizontal No 2 --- Vertical Rectangular Orifice 104.63 0.25 34.42 Vertical No **********************FLOOD FREQUENCY AND DURATION STATISTICS******************* _------ _------------ SCENARIO: PREDEVELOPED _2A Number of Subbasins: 1 Number of Links: 0 ------- --_---SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: New Structure Lnk1 ********** Link WSEL Stats WSEL Frequency Date(ft) (Recurrence Interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) 1.05-Year 102.064 1.11-Year 102.269 1.25-Year 102.520 2.00-Year 103,133 3.33-Year 103,668 5-Year 104.148 10-Year 104.888 25-Year 105.110 50-Year 105.140 100-Year 105.202 ***********Groundwater Recharge Summary *'***"'****** Recharge is computed as input to Perind Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 50.976 Total: 50.976 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 6.027 Link: New Structure Lnk1 0.000 Total: 6.027 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.323 ac-ftlyear, Post Developed: 0.038 ac-ftlyear ***********Water Quality Facility Data ************* --- _----------------- SCENARIO: PREDEVELOPED Number of Links: 0 -- __- ___---SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Structure Lnk1 Basic Wet Pond Volume (91 % Exceedance): 1162. cu-ft Computed Large Wet Pond Volume, 1.5*13asic Volume: 1744. cu-ft Infiltration/Filtration Statistics------------------- V Inflow Volume (ac-ft): 119.75 Inflow Volume Including PPT-Evap (ac-ft): 119.75 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 119.72 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)ITotal Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Link: New Structure Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) --- Discharge (cfs) ---- —--------- --- 2-Year ---- -------------------- 6.242E-03 2-Year 2.706E-03 5-Year 1.065E-02 5-Year 3.185E-03 10-Year 1.326E-02 10-Year 1.086E-02 25-Year 1.710E-02 25-Year 2.207E-02 50-Year 2.059E-02 50-Year 2.387E-02 100-Year 2.472E-02 100-Year 2.771 E-02 200-Year 3.343E-02 200-Year 2.800E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals 23 LEVEL Z FLOL) L0PT(,6L FAOUTL( MGS FLOOD PROJECT REPORT Program Version: MGSFlood 4.41 Program License Number: 200810005 Project Simulation Performed on: 08/22/2017 3:05 PM Report Generation Date: 08/22/2017 3:05 PM Input File Name: Detention Vault Sizing.fld Project Name: Federal Way Commercial (Lot B) Analysis Title: Treatment Vault Sizing Comments: PRECIPITATION INPUT Computational Time Step (Minutes): 60 Extended Precipitation Time Series Selected Climatic Region Number: 0 Full Period of Record Available used for Routing Precipitation Station: 96004005 Puget East 40 in_5min 10/01/1939-10/01/2097 Evaporation Station 961040 Puget East 40 in MAP Evaporation Scale Factor 0.750 HSPF Parameter Region Number: 1 HSPF Parameter Region Name : USGS Default Default HSPF Parameters Used (Not Modified by User) *************** ********************** WATERSHED DEFINITION *********************** Predevelopment/Post Development Tributary Area Summary Predeveloped Post Developed Total Subbasin Area (acres) 0.294 0.294 Area of Links that Include Precip/Evap (acres) 0.000 0.000 Total (acres) 0.294 0.294 ---------------------SCENARIO: PREDEVELOPED Number of Subbasins; 1 ---- ----- Subbasin: Subbasin 1---------- ------- Area (Acres) -------- Till Forest 0.294 Subbasin Total 0.294 --_---- _--------- -_.SCENARIO: POSTDEVELOPED Number of Subbasins: 1 --------- Subbasin: Subbasin 1 -------Area (Acres) Till Pasture 0.034 Impervious 0.260 Subbasin Total 0.294 ************************* LINK DATA x,** ** kFf.kR**ktk*xwi xhMNkKrx �,Lq --------------------SCENARIO: PREDEVELOPED Number of Links: 0 LINK DATA **%'*%*ki* Wr %*****xWkx*x• kk*7 --------------------SCENARIO: POSTDEVELOPED Number of Links: 1 Link Name; New Structure Lnk1 Link Type: Structure Downstream Link: None Prismatic Pond Option Used Pond Floor Elevation (ft) 100.50 Riser Crest Elevation (ft) : 107.50 Max Pond Elevation (ft) 108.00 Storage Depth (ft) 7.00 Pond Bottom Length (ft) 135.0 Pond Bottom Width (ft) 13.0 Pond Side Slopes (ft/ft) : L1= 0.00 L2= 0.00 W1= 0.00 W2= 0.00 Bottom Area (sq-ft) 1755. Area at Riser Crest El (sq-ft) 1,755. (acres) 0.040 aLt. F--r (118VI, F[ZovxVGP); 2;7,30 Ct vr. RJEC?k Volume at Riser Crest (cu-ft) 12,285. g555 .-. (ac-ft) 0.282 Z� $21 CU. FT. t'17O%= Area at Max Elevation (sq-ft) 1755. (acres) : 0.040 Vol at Max Elevation (cu-ft) 13,514. (ac-ft) 0.310 Massmann Infiltration Option Used Hydraulic Conductivity (in/hr) 0.00 Depth to Water Table (ft) : 100.00 Bio-Fouling Potential : Low Maintenance : Average or Setter Riser Geometry Riser Structure Type : Circular Riser Diameter (in) : 18.00 Common Length (ft) : 0.000 Riser Crest Elevation : 107.50 ft Hydraulic Structure Geometry Number of Devices: 2 ---Device Number Device Type Control Elevation (ft) Diameter (in) Orientation Elbow --- Device Number Device Type Control Elevation (ft) Length (in) Height (in) Orientation Elbow Circular Orifice 100.50 0.25 Horizontal No 2-- Vertical Rectangular Orifice 104.63 0.25 34.42 Vertical No **********************FLOOD FREQUENCY AND DURATION STATISTICS********W********** —-------- -.--------- SCENARIO: PREDEVELOPED �,r-� Number of Subbasins: 1 Number of Links: 0 --------------------SCENARIO: POSTDEVELOPED Number of Subbasins: 1 Number of Links: 1 ********** Link: New Structure Lnk1 ********** Link WSEL Stats WSEL Frequency Data(ft) (Recurrence interval Computed Using Gringorten Plotting Position) Tr (yrs) WSEL Peak (ft) -------------------------------------- -------------------------------------- 1.05-Year 101.779 1.11-Year 102.033 1.25-Year 102.189 2.00-Year 102.788 3.33-Year 103.222 5-Year 103,568 10-Year 104.387 25-Year 104.852 50-Year 104,919 100-Year 104.971 ***********Groundwater Recharge Summary ************* Recharge is computed as input to Perind Groundwater Plus Infiltration in Structures Total Predeveloped Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 50.976 Total: 50.976 Total Post Developed Recharge During Simulation Model Element Recharge Amount (ac-ft) Subbasin: Subbasin 1 6.027 Link: New Structure Lnk1 0.000 Total: 6.027 Total Predevelopment Recharge is Greater than Post Developed Average Recharge Per Year, (Number of Years= 158) Predeveloped: 0.323 ac-ft/year, Post Developed: 0.038 ac-ftlyear ***********Water Quality Facility Data ************* ----------------------SCENARIO: PREDEVELOPED Number of Links: 0 -------------------SCENARIO: POSTDEVELOPED Number of Links: 1 ********** Link: New Structure Lnk1 ********** Basic Wet Pond Volume (91 % Exceedance): 1162. cu-ft Computed Large Wet Pond Volume, 1.5*Basic Volume: 1744. cu-ft Infiltration/Filtration Statistics------------------- ?, b Inflow Volume (ac-ft): 119.75 Inflow Volume Including PPT-Evap (ac-ft): 119.75 Total Runoff Infiltrated (ac-ft): 0.00, 0.00% Total Runoff Filtered (ac-ft): 0.00, 0.00% Primary Outflow To Downstream System (ac-ft): 119.72 Secondary Outflow To Downstream System (ac-ft): 0.00 Percent Treated (Infiltrated+Filtered)ifotal Volume: 0.00% ***********Compliance Point Results ************* Scenario Predeveloped Compliance Subbasin: Subbasin 1 Scenario Postdeveloped Compliance Link: New Structure Lnk1 *** Point of Compliance Flow Frequency Data *** Recurrence Interval Computed Using Gringorten Plotting Position Predevelopment Runoff Postdevelopment Runoff Tr (Years) Discharge (cfs) Tr (Years) Discharge (cfs) --------------------- 2-Year ------------- ---------- 6.242E-03 2-Year 2.523E-03 5-Year 1.065E-02 5-Year 2.921 E-03 10-Year 1.326E-02 10-Year 3.288E-03 25-Year 1.710E-02 25-Year 9.375E-03 50-Year 2.059E-02 50-Year 1.220E-02 100-Year 2.472E-02 100-Year 1.465E-02 200-Year 3.343E-02 200-Year 1.824E-02 ** Record too Short to Compute Peak Discharge for These Recurrence Intervals **** Flow Duration Performance **** Excursion at Predeveloped 50%Q2 (Must be Less Than 00%): Maximum Excursion from 50%Q2 to Q2 (NRust be Less Than 0%): Maximum Excursion from Q2 to Q50 (Must be less than 10%): Percent Excursion from Q2 to Q50 (Must be less than 50%): MEETS ALL FLOW DURATION DESIGN CRITERIA: PASS -65.3% PASS -65.3% PASS -54.5% PASS 0.0% PASS T1 APPENDIX LARSGN & ASSOCIATES, INC. SURVEYORS, ENGINEERS AND PLANNERS 9027 PACIFIC AVENUE, SUITE 4 TACOMA, WA 98444 (253) 474-3404 PO WASII IN RTOR STAtt D EPART LIEYE DE ECOLOGY November 2016 GENERAL USE LEVEL DESIGNATION FOR BASIC (TSS), ENHANCED, PHOSPHORUS & OIL TREATMENT For Amerieast FilterrO 6Ecoloi?,►''�-�3ecisvta:. - - - - , r 'Based. c,n Aincricast's SLII)nlitisi-„ns, inultAing f11e Fival Teelinival Evuivaiion Repf..0s, dated Marcll 2 7. 2014 and Deccinber 2009, and additioml iiffc6rniati().0 provided it) Ecology dated �Qctnber 9. 2009' b-.01ogy horeby issues the follow 1n1; use .]evel designations: A t;c.ncra ' _!s� 1. ev.e-1 I).esignati[in lt�r: lr3a5ic, E.1lhanced, 1'hc,slil}t,rLts, and 0' 1 '1'ruattntlli a[ the fclllcr � it1 water quality Ci.esign hydraulic LoadiriG rates_ reaiittent Ls raulk Cul,dtictivitvY rrlilirati� �t Rate irllhr} fcyr teruse in �1estQlM i se In edsLem Was4ington sizing Siring hoµs tiorus 7.0. 92 alcu.latccl rtst.tl c"n listed infiltraricm raft anr3 . l�ydrtiiilk.e gradietit i,{ 1.41 inc, uInch (2.5511 &Ead with ltlticlia} _. - 2T pie- Tilt t unit IS n0i appruprtarc for uil ~pill-01it"01 1?Urpc]SOS. Ec-olugy appruvcs the l,'iltcnWk units lbr treatm'enI at thf- hydrLuriii: lclacling rates lasted al_ ovea to aell-ieve tile rnaxiin 3u1 Vvatcr cluality.desn"n f1i» Tdte. C11ic elate 010.4vaierqua1i[Y desigll Jlow- i,ates. usirlA tlac lnItc�lving pzcrcedui es: _ - - T:. 'v csterri Washington:Aor Lticalnici)l insl dlCCl ilp;trcaln c,L ctctenticrtf (ir rA renticin, flee alori; quaIit} deszg=n 41ow rate is the. pmik._I5-m tiute flow rale as calctrl.,ted using t-be sa3ldJ.iiter, ! Illt,dtllc in the latest:ve-nioil.of'the Western -'Washington liycirology ibindel or 0.ther Ecnlog).-apprcived contitluous runoff niudel. '11e model inust indicate the unit=.is carable oflprocessing 91 percQllt of'�tbic influent risriiifi fie. 4 Eastelri Washington: For troatlnent:;instalIad upstream of detrntiizn oil rotc1liibn.`t11v Ovate tluality.'clesi l flew rate is'llie peat~ 15-minute llwx rate as caluitiated using one oi' the three Llowrate based Methods dew ibed in Chapter 2.2A.() I'Llie Sunni Wei IVlat, tgoillcni ,JanU.'�l torTEastern;'Wasllibgton (SWININiEW)t7r local Mamlitl. Al ■ Entire State: For treatment installed downstream of detention, the water quality design flow rate is the full 2-year release rate of the detention facility. 4. This General Use Level Designation has no expiration date but Ecology may revoke or amend the designation, and is subject to the conditions specified below. Xcoln ,'s Conditions of Ilse: Filterra® units shall comply with these conditions shall comply with the following conditions: 1. Design, assemble, install, operate, and maintain the. Filten•a�' units in accordance with applicable Americast Filterra"o manuals, document, and the Ecology Decision. 2. Each site plan must undergo Americast Filten•a@ review before Ecology can approve the unit for site installation. This will ensure that site grading and slope are appropriate for use of a Filterre unit. 3. Filten0 media shall conform to the specifications submitted to and approved by Ecology. .4. Maintenance includes removing trash, degraded mulch, and accumulated debris from the filter surface and replacing the mulch layer. Use inspections to determine the site -specific maintenance schedules and requirements, Follow maintenance procedures given in the most recent version of the Filterra' Operation and Maintenance Manual. 5, Maintenance: The required maintenance interval for stonnwater treatment devices is often dependent upon the degree of.pollutant loading from a particular drainage basin. Therefore, Ecology does not endorse or recommend a "one size fits all" maintenance cycle for a particular model/size of manufactured filter treatment device, • Filterrao designs their systems for a target maintenance interval of 6 months. Maintenance includes removing accumulated sediment and trash from the surface area of the media, removing the mulch above the media, replacing the mulch, providing plant health evaluation, and pruning the plant if deemed necessary. •, Conduct maintenance following manufacturer's guidelines. 6. Filterra`� units come in standard sizes. 7. The minimum size filter surface -area for use in western Washington is determined by using the sand filter module in the latest version of VJWHM or other Ecology approved continuous runoff model for western Washington. Model inputs include ;a) Filter media depth: 1.8 feet b) Effective Ponding Depth: 0.75 feet (This is equivalent to the 6-inch clear zone between the top of the mulch and the bottom of the slab plus 3-inches of mulch.) ;c) Side slopes: Vertical d) Riser height: 0.70 feet e) Filter Hydraulic Conductivity: Use the Hydraulic Conductivity as listed in the table above (use the lowest applicable hydraulic conductivity depending on the level of treatment required) under Ecology's Decision, above. 2 A3 8. The minimum size filter surface -area for use in eastern Washington is determined by using the design water quality flow rate (as determined in item 3, above) and the Infiltration Rate from the table above (use the lowest applicable Infiltration Rate depending on the level of treatment required). Calculate the required area by dividing the water quality design flow rate (cu-ft/sec) by the Infiltration Rate (converted to ft/sec) to obtain required surface area (sq ft) of the Filterra unit. �9. Discharges from the Filterra0 units shall not cause or contribute to water quality standards violations in receiving waters. Approved Alternate Configurations Filterra®Internal Bypass - Pipe (FTIB-P) `1. The Filterra(D Internal Bypass — Pipe allows for piped -in flow from area drains, grated inlets, trench drains, and/or roof drains_ Design capture flows and peak flows enter the structure through an internal slotted pipe. FilterraO inverted the slotted pipe to allow design flaws to drop through to a series of splash plates that then disperse the design flows over the top surface of the Fi.lterral` planter area. Higher flows continue to bypass the slotted pipe and convey out the structure. 2. To select a FTIB-P unit, the designer must determine the size of the standard unit using the sizing guidance described above. Filterra`x lnternal 13� p.iss — Curb FTI -C 1. The Filterrao Internal Bypass —Curb model (FTIB-C) incorporates a curb inlet, biofiltration treatment chamber, and internal high flow bypass in one single structure. Filterrag designed the MB-C model for use in a "Sag" or "Sump" condition and will accept flows from both directions along a gutter line. An internal flume tray weir component directs treatment flows entering the unit through the curb inlet to the biofiltration treatment chamber. Flows in excess of the water quality treatment flow rise above the flume tray weir and discharge through a standpipe orifice; providing bypass of untreated peak flows. Americast manufactures the FTIB-C model in a variety of sizes and configurations and you may use the unit on a continuous grade when a single structure providing both treatment and high flow bypass is preferred. The FTIB-C model can also incorporate a separate junction box chamber to allow larger diameter discharge pipe connections to the structure. 2. To select a FTIB-C unit, the designer must determine the size of the standard unit using the sizing guidance described above. .Filterra' Shalio►N 1. The Filterra' Shallow provides additional flexibility for design engineers and designers in situations where there is /united depth and various elevation constraints to applying a standard Filterra® configuration. Engineers can design this system up to six inches shallower than any of the previous Filterra unit configurations noted above. a i2 -3 4. Ecale�gy' recluires'.thar till f ilterra".SIlall0w: provide a contact time eqU Valeilt to that the. siftlldard unit. This ill�alis f}► �t w.itil a slrialler depth of Media. the surface Ltr4k1 1u�tst i1>crease. TO select l iltcFra 811allow Systeln unil, [lie desigricr nlust..tust i&hlfiv isle sire o t.11e suindard un1t using ihe-rrt6de1i]lg`gruidarice describcd above. f?nce you estAblish the'size of the stRildard Filwrr,{w ti11it tj5illg the si7i.tw techlliilUe.fl� crilleci abpve., uSC llll[7M1al1011 From Ilie: R)II ow L11Y t able to select -tile aplst•nl7rIal0 size lrilter l,- �il�llc�a�v �- it T['.Gc'1t117i11 Smug MAE- L1n t Ba ��ititanieri 'ar1d� �_ . - uli°alert ShaIli�uI}ep#11 #7ndard T7��tlZ � . y 40 40 us 6x4 _..._ - --- -- --µ r - xb of 6x4._ -- _ 5x6 - '�3xR or.8x4 or 80 &6� x12_or �- 6).10 Or 10X6 �x7 .1. shallowT7'cpili i3nnc e ass thtiestaudarii d��llli u 3;5; tcF kui go;lE35y ii,as, 3:[}:fe t ee•p;(��G �?._II�EV�; Applicant: Filterra® Bioretention Systems, division of Contech Engineered Solutions, LLC- Applicant's Address: 11815 NE Glenn Widing Drive Portland, OR 97220 Application Documents: • State of Washington Department of Ecology Application for Conditional Use Designation, Americast (September 2006) ■ Quality Assurance Project Plan Filterra® Bioretention Filtration System Performance Monitoring, Americast (April 2008) • Quality Assurance Project Plan Addendum Filtezra� Bioretention Filtration System Performance Monitoring, Americast (June 2008) ■ Draft Technical Evaluation Report Filterral' Bioretention Filtration System Performance Monitoring, Americast (August 2009) ■ Final Technical Evaluation Report Filterra® Bioretention Filtration System Performance Monitoring, Americast (December 2009) • Technical Evaluation Report Appendices FilterraO Bioretention Filtration System Performance Monitoring, Americast, August 2009 • Memorandum to Department of Ecology Dated October 9, 2009 from Americast, Inc. and Herrera Environmental Consultants 4 A-Cn • Quality Assurance Project Plan Filterra® Bioretention System Phosphorus treatment and Supplemental Basic and Enhanced Treatment Performance Monitoring, Americast (November 2011) • Filterra® letter August 24, 2012 regarding sizing for the Filterra® Shallow System. • University of Virginia Engineering Department Memo by Joanna Crowe Curran, Ph. D dated March 16, 2013 concerning capacity analysis of Filterra® internal weir inlet tray. • Terraphase Engineering letter to Jodi Mills, P.E. dated April 2, 2013 regarding Terraflume Hydraulic Test, Filterra® Bioretention System and attachments. • Technical Evaluation Report, Filterra® System Phosphorus Treatment and Supplemental Basic Treatment Performance Monitoring. March 27`h, 2014. Applicant's Use Level Request: General Level Use Designation for Basic, Enhanced, Phosphorus, and Oil Treatment. Applicant's Performance Claims: Field-testing and laboratory testing show that the Filterrao unit is promising as a stormwater treatment best management practice and can meet Ecology's performance goals for basic, enhanced, phosphorus, and oil treatment. Findings of Fact: Field Testing 2013 1. Filterrae completed field-testing of a 6.5 ft x 4 ft. unit at one site in Bellingham, Washington. Continuous flow and rainfall data collected from January 1, 2013 through July 23, 2013 indicated that 59 storm events occurred. The monitoring obtained water quality data from 22 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data. 2. The system treated 98.9 percent of the total 8-month runoff volume during the testing period. Consequently, the system achieved the goal of treating 91 percent of the volume from the site. Stormwater runoff bypassed during four of the 59 storm events. 3. Of the 22 sampled events, 18 qualified for TSS analysis (influent TSS concentrations ranged from 25 to 138 mg/L). The data were segregated into sample pairs with influent concentration greater than and less than 100 mg/L. The UCL95 mean effluent concentration for the data with influent less than 100 mg/L was 5.2 mg/L, below the 20- mg/L threshold. Although the TAPE guidelines do not require an evaluation of TSS removal efficiency for influent concentrations below 100 mg/L, the mean TSS removal for these samples was 90.1 percent. Average removal of influent TSS concentrations greater than 100 mg/L (three events) was 85 percent. In addition, the system consistently exhibited TSS removal greater than 80 percent at flow rates at a 100 inches per hour [in/hr] infiltration rate and was observed at 150 in/hr. W 4. Ten of the 22 sampled events qualified for TP analysis. Americast augmented the dataset using two sample pairs from previous monitoring at the site. Influent TP concentrations ranged from 0.11 to 0.52 mg/L. The mean TP removal for these twelve events was 72.6 percent. The LCL95 mean percent removal was 66.0, well above the TAPE requirement of 50 percent. Treatment above 50 percent was evident at 100 in/hr infiltration rate and as high as 150 in/hr. Consequently, the Filterra® test system met the TAPE Phosphorus Treatment goal at 100 in/hr. Influent ortho-P concentrations ranged from 0.005 to 0.012 mg/L; effluent ortho-P concentrations ranged from 0.005 to 0.013 mg/L. The reporting limit/resolution for the ortho-P test method is 0.01 mg/L, therefore the influent and effluent ortho-P concentrations were both at and near non -detect concentrations. Field Testing2009 1. Filterrao completed field-testing at two sites at the Port of Tacoma. Continuous flow and rainfall data collected during the 2008-2009 monitoring period indicated that 89 storm events occurred. The monitoring obtained water quality data from 27 storm events. Not all the sampled storms produced information that met TAPE criteria for storm and/or water quality data. 2. During the testing at the Port of Tacoma, 98.96 to 99.89 percent of the annual influent runoff volume passed through the POT1 and POT2 test systems respectively. Stormwater runoff bypassed the POT test system during nine storm events and bypassed the POT2 test system during one storm event. Bypass volumes ranged from 0.13% to 15.3% of the influent storm volume. Both test systems achieved the 91 percent water quality treatment - goal over the 1-year monitoring period. 3. Consultants observed infiltration rates as high as 133 in/hr during the various storms. Filterra® did not provide any paired data that identified percent removal of TSS, metals, oil, or phosphorus at an instantaneous observed flow rate. 4. The maximum storm average hydraulic loading rate associated with water quality data is <40 in/hr, with the majority of flow rates < 25 in/hr. The average instantaneous hydraulic loading rate ranged from 8.6 to 53 inches per hour. 5. The field data showed a removal rate greater than 80% for TSS with an influent concentration greater than 20 mg/1 at an average instantaneous hydraulic loading rate up to 53 in/hr (average influent concentration of 28.8 mg/l, average effluent concentration of 4.3 mg/1). 6. The field data showed a removal rate generally greater than 54% for dissolved zinc at an average instantaneous hydraulic loading rate up to 60 in/hr and an average influent concentration of 0.266 mg/1(average effluent concentration of 0.115 mg/1). 7. The field data showed a removal rate generally greater than 40% for dissolved copper at an average instantaneous hydraulic loading rate up to 35 in/hr and an average influent concentration of 0.0070 mg/1(average effluent concentration of 0.0036 mg/1). 8. The field data showed an average removal rate of 93% for total petroleum hydrocarbon (TPH) at an average instantaneous hydraulic loading rate up to 53 in/hr and an average influent concentration of 52 mg/1(average effluent concentration of 2.3 mg/1). The data A'i also shows achievement of less than 15 mg/l TPH for grab samples- Filterrao provided limited visible sheen data due to access limitations at the outlet monitoring location. The field data showed low percentage removals Of total phosphorus at all storm flows at an average influent concentration of 0.189 mgll (average effluent concentration of 0.171 mg/1). We may relate the relatively poor treatment performance of the Filterrao system at this location to influent characteristics for total phosphorus that are unique to the Port of Tacoma site. It appears that the Filterrag system will not meet the 50 percent removal performance goal when you expect the majority of phosphorus in the runoff'to be in the dissolved form. Labors#ory Test 1. Filterra-v performed laboratory testing on a scaled down version of the Filterrao unit. The lab data showed an average removal from 83-91% for TSS with influents ranging from 21 to 320 m&4 , 82-84% for total copper with influents ranging from 0.94 to 2.3 mg/L, and 50-61 % for orthophosphate with influents ranging from 2.46 to 14.37 mg/L. 2. Filterrao conducted permeability tests on the soil media. 3. Lab scale testing using Sil-Co-Sil 106 showed percent removals ranging from 70.1 % to 95.5% with a median percent removal of 90.7%, for influent concentrations ranging from 8.3 to 260 mg/L. Filterra* ran these laboratory tests at an infiltration rate of 50 inlbr. 4. Supplemental lab testing conducted in September 2009 using Sil-Co-Sil 106 showed an average percent removal of 90.6%. These laboratory tests were run at infiltration rates ranging from 25 to 150 inihr for influent concentrations ranging from 41.6 to 252.5 mg/i. Regression analysis results indicate that the Filterrao system's TSS removal performance is independent of influent concentration in the concentration rage evaluated at hydraulic loading rates of up to 150 inthr. Contact Information: Applicant: Jeremiah Lehman Contech Engineered Solutions, LLC. 11815 Glenn Widing Dr Portland, OR 97220 (503) 258-3136 'leman conteches.com Applicant's Website: b9 •//www conteches.com Ecology web link: h :/lwww.ec .wa. ovl ro w q/stormwater/newteehlindex.httnl Ecology: Douglas C. Howie, P.E. Department of Ecology Water Quality Program (360) 407-6444 don las bowie „•�L$•� Milk Date Revision December 2009 GULD for Basic, Enhanced, and Oil granted, CULD for Phosphorus September 2011 Extended CULD for Phosphorus Treatment Revised design storm discussion, added Shallow System. September 2012 January 2013 Revised format to match Ecology standards, changed Filterra contact information Added FTIB-P system Februgg 2013 March 2013 Added FTIB-C system April 2013 Modified requirements for identifying appropriate size of unit June 2013 Modified description of FTIB-C alternate configuration GULD awarded for Phosphorus Treatment. GULD updated for a higher flow -rate for Basic Treatment. March 2014 June 2014 Revised sizing calculation methods March 2015 Revised Contact Information June 2015 CULD for Basic and Enhanced at 100 in/hr infiltration rate November 2015 Removed information on CULD (created separate CULD document for 100 in/hr infiltration rate June 2016 Revised text regarding Hydraulic conductivity value November 2016 Revised Contech Contact information DRAFT GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED NEW DENTAL OFFICE PARCEL NO.415920-0715 SW CAMPUS DRIVE AND 1ST AVENUE SOUTH FEDERAL WAY, WASHINGTON 98023 Project No. 062-16008 JANUARY 20, 2017 Prepared for: COVENANT GROUP ATTN: MS. JULIE A. MARGETICH 2044 CALIFORNIA AVENUE CORONA, CA 92881 Prepared by: KRAZAN & ASSOCIATES, INC. GEOTECHNICAL ENGINEERING DIVISION 4303 —198" St SW Lynnwood, Washington 98036 (425) 485-5519 or look —= an & ASSOCIATES, INC. GEOTECHNICAL ENGINEERING • ENVIRONMENTAL ENGINEERING CONSTRUCTION TESTING & INSPECTION January 20, 2017 DRAFT Krazan File Number 062-16008 Covenant Group 2044 California Avenue Corona, CA 92881 Attention: Ms. Julie A. Margetich Email: Marg_etichJ@pacificdentalservices.cam Tel: (951) 582-5745 Reference: Geotechnical Engineering Investigation Proposed New Dental Office Parcel No. 415920-0715 SW Campus Drive & 1" Avenue South Federal Way, WA Greetings, In accordance with your request, we have completed a Geotechnical Engineering Investigation for the referenced site. The results of our investigation are presented in the attached report. If you have any questions, or if we can be of further assistance, please do not hesitate to contact our office. Respectfully submitted, KRA7.AN & ASSOCIATES, INC. Michael D. Rundquist, P.E. Senior Project Manager JGL/MDR Offices Serving The Western United States 4303 —19811 St SW • Lynnwood, Washington 98036 • (425) 485-5519 • Fax: (425) 485-6837 W *azar� & ASSOCIATES,INC. GEOTECHNICAL ENGINEERING • ENVIRONMENTAL ENGINEERING CONSTRUCTION TESTING & INSPECTION January 20, 2017 KA Project No. 062-16008 DRAFT GEOTECHNICAL ENGINEERING INVESTIGATION PROPOSED DENTAL OFFICE PARCEL NO.415920-0715 SW CAMPUS WAY & 1sT AVENUE SOUTH FEDERAL WAY, WASHINGTON 98023 INTRODUCTION This report presents the results of our Geotechnical Engineering Investigation for the proposed dental office project located near the intersection of SW Campus Way and 111 Avenue South in Federal Way, Washington as shown on the Vicinity Map in Figure 1. The project site consists of parcel number 4159200715. ' Discussions regarding site conditions are presented in this report, together with conclusions and recommendations pertaining to site preparation, excavations, foundations, structural fill, utility trench backfill, drainage, and erosion control. To aid in the preparation of this report, we have been provided with a land survey and conceptual site plan. The survey was prepared be Barghausen Consulting Engineers, Inc. and is titled, "ALTA/NSPS Land Titled Survey — A Portion of the NE1/4 of the SE1/4 of Sec. 19, TWR 21 North, RGE. 4 East, W.M. — City of Federal Way, King County WA.," dated September 17, 2016. The conceptual site plan does not include the name of the author and is titled, "Federal Way, WA — Conceptual Site Option 4 (drive thru)," dated September 22, 2016 (corrected). A site plan showing the approximate exploratory soil boring locations is presented in Figure 2 following the text of this report. A description of the field investigation as well as the exploratory soil boring logs and laboratory test results are presented in Appendix A. Appendix B contains a guide to aid in the development of earthwork specifications. Pavement design guidelines are presented in Appendix C. The recommendations in the main text of the report have precedence over the more general specifications in the appendices. PURPOSE AND SCOPE This investigation was conducted to evaluate the subsurface soil and groundwater conditions at the site, to develop geotechnical engineering recommendations for use in project design and to provide criteria for site preparation and earthwork construction. Offices Serving The Western United States 4303 — 198'h St SW • Lynnwood, Washington 98036 • (425) 485-5519 • Fax: (425) 485-6837 An KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 2 Our services were performed in general accordance with our proposal for this project, dated October 12, 2016 (Krazan proposal number G16025WAP). The geotechnical services performed for this project generally include the following: • Exploration of the subsurface soil and groundwater conditions by conducting two (2) soil borings using a subcontracted drill rig; • A site plan showing the soil boring locations; • Comprehensive soil logs including soil stratification and classification, and groundwater levels where applicable; • Recommendations for foundation design including foundation type, allowable foundation bearing pressure, anticipated settlements (both total and differential), coefficient of horizontal friction, and frost penetration depth; • Recommendations for seismic design considerations, including site coefficient and ground acceleration based on the 2012/2015 International Building Code (IBC); • Construction and excavation considerations, topsoil/unsuitable soil stripping depth, identification of potentially problematic soil or groundwater conditions, and approximate depth of over -excavation if required; • Recommendations for structural fill materials, placement, and compaction; • General recommendations for site drainage and erosion control. PROPOSED CONSTRUCTION It is our understanding that the proposed development will include anew dental office. Preliminary plans indicate that the planned development will be located in an existing parking lot area. Significant re -grading is not anticipated. New underground utilities will likely be installed, connecting nearby utilities with the planned development. SITE CONDITIONS The property is located in a retail area on the eastern side of SW Campus Drive, approximately 400 feet northwest of lst Avenue South. The proposed development is currently a paved parking lot. The planned building area is nearly level, with landscaping along the northern, southern and western sides of the property. A sidewalk and additional paved parking areas are located in the eastern portion of the site. A concrete retaining wall, approximately 5 to 6 feet tall, is located in the western portion of the property, with a stormwater swale near the toe of the wall along SW Campus Drive. Site plans indicate that the western portion of the parcel includes a storinwater easement with a subsurface vault below the parking lot. Krazan & Associates, Inc. Offices Serving The Western United States ��3 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 3 According to the ALTA/NSPS Land Title Survey by Barghausen Associates Consulting Engineers, Inc., the elevation across the site ranges from approximately 232 feet in the stormwater swale near the southwestern corner of the parcel, to about 245 feet in the parking lot area near the northeastern corner of the site. The site is bordered by commercial properties to the north, east and south, including a grocery store north to the north and a restaurant to the southeast. SW Campus Drive borders the site to the west. GEOLOGIC SETTING The "Geologic Map of the Poverty Bay 7.5' Quadrangle, King and Pierce Counties, Washington," by D.B. Booth, H.H. Waldron, and K.G. Troost (USGS 2004) indicates that the site area is underlain by Quaternary Vashon recessional outwash (Qvr), with Quaternary Vashon ice -contact deposits (Qvi) and Quaternary Vashon glacial till (Qvt) mapped nearby. Recessional outwash typically consists of poorly to moderately sorted, medium dense sand and gravel with cobbles. Ice -contact deposits are generally described as poorly sorted sand and gravel in a silty matrix, possibly including lenses of glacial till. Glacial till typically consists of a very compact, unsorted mixture of clay, silt, sand, gravel, cobbles and boulders. FIELD INVESTIGATION Two (2) exploratory soil borings were completed to evaluate the subsurface soil and groundwater conditions in the proposed development area. The soil borings were completed on November 29, 2016 with a subcontracted drill rig, and the soil borings extended to depths of approximately 21.5 feet to about 31.5 feet below the existing ground surface. A geologist and engineer from Krazan and Associates were present during the explorations, examined the soil and geologic conditions encountered, obtained samples of the different soil types, and maintained logs of the explorations. The approximate locations of the soil borings are shown on the Site Plan in Figure 2. Representative samples of the subsurface soils encountered in the geotechnical explorations were collected and sealed in plastic bags. The soils encountered in the exploratory soil borings were visually classified in general accordance with the Unified Soil Classification System (USCS). A more detailed description of the field investigation is presented in Appendix A. SOIL PROFILE AND SUBSURFACE CONMITIONS The information provided below includes a brief summary of the materials encountered in the soil explorations. Detailed soil logs are presented in Appendix A. Krazan & Associates, Inc. Offices Serving The Western United States /\IN KRAZAN & ASSOCIATES, INC. KANo. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 4 Soil boring 13-1 was located in the southern portion of the proposed building pad. Boring B-1 encountered approximately 2.0 inches of asphalt overlying about 3.0 inches of crushed rock - 'Underlying the crushed rock, soil Boring B-1 encountered medium dense to very dense, brown gravel with sand to a depth of about 12.0 feet below existing grade. We interpreted the brown gravel with sand to be compacted fill material. Below the fill material, the soil boring primarily encountered very stiff, gray silt with clay and trace sand to the depth explored of approximately 26.5 feet below the ground surface. We interpreted the silt with clay to be native lacustrine deposits (ancient lake bed sediment). Soil boring B-2 was located in the northwestern portion of the proposed building pad. Boring B-2 encountered approximately 3.0 inches of asphalt overlying about 2.0 inches of crushed rock. Underlying the crushed rock, soil Boring B-2 encountered medium dense to very dense, brown gravel with sand to a depth of about 16.0 feet below existing grade. We interpreted the brown gravel with sand to be compacted fill material. Below the fill material, the soil boring encountered very stiff to bard, gray silt with clay and trace sand to the depth explored of approximately 31.5 feet below the ground surface. We interpreted the silt with clay to be native lacustrine deposits (ancient lake bed sediment). There is a potential for cobbles and there may be debris in the fill material. There is also the potential for layers of organic topsoil, loose/soft soils, and/or undocumented fill in unexplored areas of the site. GROUNI DWATER The soil borings were checked for the presence of groundwater during drilling operations. Groundwater seepage was observed at a depth of approximately 11 A feet in B-1 and at a depth of about 15.0 feet in B-2 during the geoteahnical explorations. We interpreted the groundwater seepage to be perched groundwater. Perched water occurs when surface water infiltrates through less dense, more permeable soils and accumulates on top of a relatively low permeability soil layer. 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 perched water to decrease during drier times of the year and increase during wetter periods. It should be recognized that groundwater elevations may fluctuate with time. The groundwater level will be dependent upon seasonal precipitation, irrigation, land use, and climatic conditions, as well as other factors. Therefore, groundwater levels at the time of the field investigation may be different from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report. Krazan & Associates, Inc. Offices Serving The Western United States MG KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 5 GEOLOGIC HAZARDS Erosion Concern/Hazard The Natural Resources Conservation Services (MRCS) map for King County indicates that the soils in the site area consist of Everett Alderwood Gravelly Sandy Loams, 6 to 15 percent slopes (EwC). The mapped soil unit is described as having a moderate potential for soil erosion when exposed. It has been our experience that soil erosion potential can be minimized through landscaping and surface water runoff control. Typically, erosion of exposed soils will be most noticeable during periods of rainfall and may be controlled by the use of normal temporary erosion control measures, such as silt fences, hay bales, mulching, control ditches or diversion trenching, and contour furrowing. Erosion control measures should be in place before the onset of wet weather. Seismic Hazard The 2015 International Building Code (IBC), Section 1613.3.2, refers to Chapter 20 of ASCE-7 for Site Class Definitions. It is our opinion that the overall soil profile corresponds to Site Class D as defined by Table 20.3-1 "Site Class Definitions," according to the 2010 ASCE-7 Standard. Site Class D applies to a "stiff soil' profile. The seismic site class is based on a soil profile extending to a depth of 100 feet. The soil borings on this site extended to a maximum depth of 31.5 feet and this seismic site class designation is based on the assumption that similar soil conditions continue below the depth explored. We referred to the U.S. Geological Survey (USGS) Earthquake Hazards Program Website and 2012/2015 IBC to obtain values for Ss, S,us, SDs, Sr, Sul, SDI, Fa, and Fv. The USGS website includes the most updated published data on seismic conditions. The seismic design parameters for this site are presented in the following table: Krazan & Associates, Inc. Offices Serving The Western United States 10 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 6 Table 1: Seismic Design Parameters (Reference: 2015 IBC Section 1613.3.2, ASCE, and USGS) Seismic Item Value Site Class D Site Coefficient Fa 1.000 Ss 1.287 g SMs 1.287 g SDs 0.858 g Site Coefficient F,. 1.504 St 0.496 g SMI 0.746 g SDI 0.497 g Additional seismic considerations include liquefaction potential and amplification of ground motions by soft soil deposits. The liquefaction potential is highest for loose sand with a high groundwater table. The native soils primarily consisting of stiff to hard silt with clay that are interpreted to underlie the site are considered to have a low potential for liquefaction and amplification of ground motion. CONCLUSIONS AND RECOMMENDATIONS General It is our opinion from a geotechnical standpoint that the site is compatible with the proposed development, provided that our geotechnical recommendations are incorporated into project plans and are implemented during construction. Soil Conditions: Our soil explorations generally encountered medium dense to very dense gravel with sand to depths ranging from about 12 to 16 feet, overlying very stiff to hard silt with clay soils. The gravel with sand is interpreted to be compacted fill material, and the underlying silt with clay soils are interpreted to be native lacustrine deposits (ancient lake bed sediment). The silt and clay appear to be partially consolidated. Foundations: Based on our explorations, conventional spread foundations bearing on the medium dense to very dense fill material should provide adequate support for the planned structures. Krazan & Associates, Inc. Offices Serving The Western United States P`-1 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 7 It is our understanding that there is an underground stormwater vault along the western edge of the proposed building pad. The proposed building might apply surcharge loads to the vault walls if the western footing line incorporates a standard design depth next to the stormwater easement. Accordingly, consideration should be given to the proposed depth and location of the western foundation line to minimize surcharge loads. Detailed geotechnical engineering recommendations for foundation design are presented in this report. Moisture Sensitive Soils: The granular fill materials encountered in our explorations are not considered to be moisture sensitive. However, the underlying native silty clay soils are considered to be moisture sensitive and will be difficult or impossible to compact in wet conditions. Based on our explorations, the moisture sensitive materials were encountered approximately 12 to 16 feet below grade. The moisture content of the silty soils is important in determining if the soils can be used as structural fill at the time of construction. Krazan and Associates is available on request to evaluate the suitability of the on -site soils for use as structural fill material during earthwork construction. Site Preparation General site clearing should include removal of vegetation; trees and associated root systems; wood; abandoned utilities; structures including foundations, basement walls and floors; rubble; and rubbish. Site stripping should extend until all organics in excess of 3 percent by volume are removed. These materials will not be suitable for use as structural fill. However, stripped topsoil may be stockpiled and used in landscape or non-structural areas. After stripping operations, the building pad and pavement areas should be proof -rolled and visually inspected to identify any areas of soft/loose soil. Any remaining loose soils should be excavated to expose firm native soils. The resulting excavations should be filled with approved structural fill. Structural fill material should be within f 2 percent of the optimum moisture content, and the soils should be compacted to a minimum of 95 percent of the maximum dry density as determined by ASTM D1557 Test Method. During wet weather conditions, subgrade stability problems and grading difficulties may develop due to excess moisture, disturbance of sensitive soils and/or the presence of perched groundwater. Construction during the extended periods of wet weather could result in the need to remove wet disturbed soils if they cannot be suitably compacted due to elevated moisture contents. Some of the on - site soils have significant silt content and are considered to be moisture sensitive, and can be easily disturbed when wet. If over -excavation is necessary, it should be confirmed through continuous monitoring'and testing by a qualified geotechnical engineer or geologist. Soils that have become unstable may require drying to near their optimal moisture content before compaction is feasible. Krazan & Associates, Inc. Offices Serving The Western United States KRAZAN & ASSOCIATES, INC. KANo. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 8 Selective drying may be accomplished by scarifying or windrowing surficial material during extended periods of dry, warm weather (typically during the summer months). If the soils cannot be dried back to a workable moisture condition, remedial measures may be required. . General project site winterization should consist of the placement of aggregate base and the protection of exposed soils during the construction phase. It should be understood that even if Best Management Practices (BMPs) for wintertime soil protection are implemented and followed there is a significant chance that moisture disturbed soil mitigation work will still be required. Any buried structures encountered during construction should be properly removed and backfilled. Excavations, depressions, or soft and pliant areas extending below the planned finish subgrade levels should be excavated to expose firm undisturbed native soil, and backfilled with structural fill. In general, any septic tanks, underground storage tanks, debris pits, cesspools, or similar structures should be completely removed. Concrete footings should be removed to an equivalent depth of at least 3 feet below proposed footing elevations or as recommended by the geotechnical engineer. The resulting excavations should be backfilled with structural fill. A representative of our firm should be present during all site clearing and grading operations to observe, test and evaluate earthwork construction. This testing and observation is an integral part of our service, as acceptance of earthwork construction is dependent upon compaction and stability of the material. The geotechnical engineer may reject any material that does not meet compaction and stability requirements. Further recommendations, contained in this report, are predicated upon the assumption that earthwork construction will conform to the recommendations set forth in this section and in the Structural Fill Section of this report. Temporary Exc ations The on -site soils have variable cohesion strengths, therefore the safe angles to which these materials may be cut for temporary excavations is variable, as the soils may be prone to caving and slope failures in temporary excavations deeper than 4 feet. Temporary excavations in medium dense soils should be sloped no steeper than 1.5H:1 V (horizontal to vertical) where room permits. The dense to very dense granular soils may be sloped to inclinations of 1H:1V. If groundwater seepage is encountered in temporary excavations, then we anticipate that flatter inclinations might be necessary. All temporary cuts should be in accordance with Washington Administrative Code (WAC) Part N, Excavation, Trenching, and Shoring. The temporary slope cuts should be visually inspected daily by a qualified person during construction work activities and the results of the inspections should be included in daily reports. The contractor is responsible for maintaining the stability of the temporary cut slopes and minimizing slope erosion during construction. The temporary cut slopes should be covered with plastic sheeting to help minimize erosion during wet weather and the slopes should be Krazan & Associates, Inc. Offices Serving The Western United States NI KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 9 closely monitored until the permanent retaining systems are complete. Materials should not be stored and equipment operated within 10 feet of the top of any temporary cut slope. A Krazan & Associates geologist or geotechnical engineer should observe, at least periodically, the temporary cut slopes during the excavation work. The reasoning for this is that all soil conditions may not be fully delineated by the limited sampling of the site from the geotechnical explorations. In the case of temporary slope cuts, the existing soil conditions may not be fully revealed until the excavation work exposes the soil. Typically, as excavation work progresses, the maximum inclination of the temporary slope will need to be evaluated by the geotechnical engineer so that supplementaf recommendations can be made. Soil and groundwater conditions can be highly variable. Scheduling for soil work will need to be adjustable, to deal with unanticipated conditions, so that the project can proceed smoothly and required deadlines can be met. If any variations or undesirable conditions are encountered during construction, Krazan & Associates should be notified so that supplemental recommendations can be made. structural Fill 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. 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 subsection of this report prior to beginning fill placement. Typically, imported all-weather structural fill material should consist of well -graded gravel, or sand and gravel mixture, with a maximum grain size of 3 inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). All structural fill material should be submitted for approval to the geotechnical engineer at least 48 hours prior to delivery to the site. Fill soils should be placed in horizontal lifts not exceeding 8 inches in thickness prior to compaction, moisture -conditioned as necessary, (moisture content of soil shall not vary by more than f2 percent of optimum moisture) and the material should be compacted to at least 95 percent of the maximum dry density based on ASTM D1557 Test Method. In -place density tests should be performed on all structural fill to document proper moisture content and adequate compaction. Additional lifts should not be placed if the previous lift did not meet the compaction requirements or if soil conditions are not considered stable. Krazan & Associates, Inc. Offices Serving The Western United States M-0 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 10 Foundation% General: The proposed building may be supported on a conventional spread foundation system bearing on the granular medium dense or finner soils. The medium dense to very dense granular soils at the site are interpreted to be compact fill material. We recommend that the foundation subgrade soils be evaluated during construction to determine the consistency throughout the building pad. Western Foundation Line: It is our understanding that there is an underground stormwater vault along the western edge of the proposed building pad. Based on the available information from the plans and a stormwater utility map, the proposed western building foundation may be in close proximity to the vault retaining wall. Accordingly, we recommend that the western foundation of the proposed building be deepened or moved laterally to maintain a 1 Horizontal to 1 Vertical (1H:1V) geometry between the bottom of the existing vault foundation and the bottom of the proposed building foundation. Soil Bearing: Conventional shallow spread footings supported on medium dense of firmer granular soils, or on structural fill extending to the medium dense or firmer soils, may be designed using an allowable bearing pressure of 2,000 pounds per square foot (psf) for dead plus live loads. This value may be increased by 113 for short duration loads such as wind or seismic loading. A representative of Krazan and Associates should evaluate the foundation bearing soil and observe structural fill placement. Footings should have a minimum embedment depth of 18 inches below pad subgrade (soil grade) or adjacent exterior grade, whichever is lower. Footing widths should be based on the anticipated loads and allowable soil bearing pressure. Footings should have a minimum width of at least 12 inches regardless of load. Water should not be allowed to accumulate in footing trenches. All loose or disturbed soil should be removed from the foundation excavations prior to placing concrete. Water should not be allowed to collect in the foundation excavations. Structural Fill in Footing Areas: If structural fill is placed beneath foundations, the footing trenches would need to be widened on both sides of the footing a distance equal to one-half of the thiclmess of the structural fill layer to be placed below the bottom of the footing. Structural fill material should consist of well -graded gravel, or sand and gravel mixture, with a maximum grain size of 3 inches and less than 5 percent fines (material passing the U.S. Standard No. 200 Sieve). All structural fill material should be submitted for approval to the geotechnical engineer at least 48 hours prior to delivery to the site. Footing excavations should be inspected to verify that the foundations will bear on suitable material. Potential Foundation Settlement: For foundations constructed as recommended, the total settlement is not expected to exceed 1-inch. Differential settlement, along a 20-foot exterior wall footing or between Krazan & Associates, Inc. offices Serving The Western United States /Nit KRAZAN & ASSOCIATES, INC. KA No.-062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 11 adjoining column footings, should be less than '/z-inch. Most settlement is expected to occur during construction, as the loads are applied. However, additional post -construction settlement may occur if the foundation soils are flooded or saturated. It should be noted that the risk of liquefaction is considered low, given the composition and density of the native, on -site soils. Footing Drains: Seasonal rainfall, water ran -off, and the normal practice of watering trees and landscaping areas around the proposed structures, should not be permitted to flood and/or saturate foundation subgrade soils. To prevent the buildup of water within the footing areas, continuous footing drains (with cleanouts) should be provided at the bases of the footings. The footing drains should consist of a minimum 4-inch diameter rigid perforated PVC pipe, sloped to drain, with perforations placed near the bottom. The drainpipe should be enveloped by 1-inch sized washed rock in all directions and wrapped with filter fabric to prevent the migration of silt and clay into the drain. If free -draining materials are exposed in the foundation subgrade, then footing drains may not be necessary. This can be evaluated during building pad excavation. Design Parameters — Lateral Resistance: Resistance to lateral footing displacement can be computed using an allowable friction factor of 0.35 acting between the bases of foundations and the supporting subgrade soil. Lateral resistance for footings can alternatively be developed using an allowable equivalent fluid passive pressure of 250 pounds per cubic foot (pef) acting against the appropriate vertical footing faces (neglecting the upper 12 inches). The allowable friction factor and allowable equivalent fluid passive pressure values include a factor of safety of 1.5. The frictional and passive resistance of the soil may be combined without reduction in determining the total lateral resistance. A 1/3 increase in the above values may be used for short duration, wind and seismic loads. Soil Sulfate Content: It is our understanding that the sulfate content of soils can affect the type of concrete used for the foundations. Soil samples from each boring at about 2.5 feet in depth were sent to Am Test, Inc. in Kirkland, Washington for water-soluble sulfate testing using method EPA 300.0. Laboratory test results are presented in Table 1 below. Tubie 1; Solah e SuifaOc. Content of Soils Sample I.D. Test Result (µg/g) < 10 Test Result (% by mass) Sample 1 (B-1 at 2.5') < 0.0010 Sample 2 (B-2 at 2.5') < 10 < 0.0010 Krazan & Associates, Inc. Offices Serving The Western United States )\711 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 12 According to ACI 318-14 Table 19.3.1.1 — "Exposure categories and classes," both samples would be included in Sulfate Class SO with (SO42) < 0.10 percent by mass. According to ACI 318-14 Table 19.3.2.1 — "Requirements for concrete by exposure class," there are no cementitious materials type restrictions for exposure class SO soils. Floor Slabs and Exterior Flatwork For building floor slab subgrades prepared in accordance with the recommendations presented in the Site Preparation section of this report, floor slabs may be designed using a modulus of subgrade reaction value of k = 200 pounds per cubic inch (pci) for slabs supported on medium dense or firmer soils or on structural fill extending to medium dense or firmer soils. In areas where it is desired to reduce floor dampness, such as areas covered with moisture sensitive floor coverings, we recommend that concrete slab -on -grade floors be underlain by a water vapor retarder system. The water vapor retarder should consist of a plastic vapor retarder sheeting underlain by a minimum of 4-inches of compacted clean (less than 5 percent passing the U.S. Standard No. 200 Sieve), open -graded coarse rock of Y4-inch maximum size. The vapor retarder sheeting should be protected from puncture damage. Moisture within the structure may be derived from water vapors, which were transformed from the moisture within the soils. This moisture vapor can travel through the vapor membrane and penetrate the slab -on -grade. This moisture vapor penetration can affect floor coverings and produce mold and mildew in the structures. To minimize moisture vapor intrusion, it is recommended that a vapor retarder be installed in accordance with ASTM guidelines. It is recommended that the utility trenches within the structures be compacted, as specified in our report, to minimize the transmission of moisture through the utility trench backfill. Under -slab drainage should be considered if floor moisture is a concern. Special attention to the immediate drainage and irrigation around the buildings is recommended. Positive drainage should be established away from the structures and should be maintained throughout the lives of the structures. Water should not be allowed to collect adjacent to the structures. Over -irrigation within landscaped areas adjacent to the structures should not be performed. In addition, ventilation of the structures may be prudent to reduce the accumulation of interior moisture. Lateral Earth Pressures and Retainin Walls We have developed criteria for the design of retaining or below grade walls. Our design parameters are based on retention of the in -place soils. The parameters are also based on level, well -drained wall backfill conditions. Walls may be designed as "restrained" retaining walls -based on "at -rest" earth pressures, plus any surcharge on top of the walls as described below, if the walls are braced to restrain movement and/or movement is not acceptable. Unrestrained walls may be designed based on "active" earth pressure, if the walls are not part of the buildings and some movement of the retaining walls is Krazan & Associates, Inc. Offices Serving The Western United States A ll3 KR.AZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 13 acceptable. Acceptable lateral movement equal to at least 0.2 percent of the wall height would warrant the use of "active" earth pressure values for design. 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 35 pcf for yielding (active condition) walls, and 55 pcf for non -yielding (at -rest condition) walls. The stated lateral earth pressures do not include the effects of hydrostatic pressure generated by water accumulation behind the retaining walls or loads imposed by construction equipment, slopes, foundations or roadways adjacent to the wall (surcharge loads). To minimize the lateral earth pressure and prevent the buildup of water pressure against the walls, continuous footing drains (with cleanouts) should be provided at the bases of the walls. The footing drains should consist of a minimum 4-inch diameter perforated pipe, sloped to drain, with perforations placed near the bottom. The drainpipe should be enveloped by 6 inches of washed gravel in all directions wrapped in filter fabric to prevent the migration of silt and clay into the drain. The wall fill adjacent to and extending a lateral distance of at least 2 feet behind the walls should consist of free -draining granular material. All free -draining backfill should contain less than 3 percent fines (passing the U.S. Standard No. 200 Sieve) based upon the fraction passing the U.S. Standard No. 4 Sieve with at least 30 percent of the material being retained on the U.S. Standard No. 4 Sieve. Alternatively, a drainage composite may be used. It should be realized that the primary purpose of the free -draining material is the reduction of hydrostatic pressure. Some potential for the moisture to contact the back face of the wall may exist, even with treatment, which may require that more extensive waterproofing be specified for walls, which require interior moisture sensitive finishes. We recommend that the wall fill be compacted to at least 95 percent of the maximum dry density based on ASTM D1557 Test Method. In -place density tests should be performed to verify adequate compaction. Soil compactors place transient surcharges on the backfill. Consequently, only light hand operated equipment is recommended for fill compaction within 3 feet of walls so that excessive stress is not imposed on the walls. Erosion and Sediment Control Erosion and sediment control (ESC) is used to minimize the transportation of sediment to wetlands, streams, lakes, drainage systems, and adjacent properties. Erosion and sediment control measures should be implemented and these measures should be in general accordance with local regulations. As a minimum, the following basic recommendations should be incorporated into the design of the erosion and sediment control features of the site: 1) Phase the soil, foundation, utility and other work, requiring excavation or the disturbance of the site soils, to take place during the dry season (generally May through September). However, Krazan & Associates, Inc. Offices Serving The Western United States IL4 KRAZAN & ASSOCIATES, INC. KANo. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 14 provided precautions are taken using Best Management Practices (BMP's), grading activities can be undertaken during the wet season (generally October through April), but it should also be known that this may increase the overall cost of the project. 2) All site work should be completed and stabilized as quickly as possible. 3) Additional perimeter erosion and sediment control features may be required to reduce the possibility of sediment entering the surface water. This may include additional silt fences, silt fences with a higher Apparent Opening Size (AOS), construction of a berm, or other filtration systems. 4) Any runoff generated by dewatering discharge should be treated through construction of a sediment trap if there is sufficient space. If space is limited, other filtration methods will need to be incorporated. 4 Groundwater Influence on Structures and Earthwork Construction i Groundwater seepage was encountered in the soil borings at the time of our site visit. It should be ' recognized that groundwater elevations may fluctuate with time. The groundwater level will be dependent upon seasonal precipitation, irrigation, land use, and climatic conditions, as we11 as ther o factors. Therefore, groundwater levels at the time of the field investigation may be different from those encountered during the construction phase of the project. The evaluation of such factors is beyond the scope of this report. If groundwater is encountered during construction, we should observe the conditions to determine if dewatering will be needed. Design Of temporary dewatering systems to remove groundwater should be the responsibility of the contractor. If earthwork is performed during or soon after periods of precipitation, the subgrade soils may become saturated. These soils may "pump," and the materials may not respond to densification techniques. Typical remedial measures include: disking and aerating the soil during dry weather; mixing the soil with drier materials; removing and replacing the soil with an approved fill material. A qualified geotechnical engineering firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations. If earthwork is performed during or soon after periods of precipitation, the subgrade soils may become saturated. These soils may "pump," and the materials may not respond to densification techniques. Typical remedial measures include; disking and aerating the soil during dry weather, mixing the soil with drier materials; removing and replacing the soil with an approved fill material. A qualified geotechnical engineering firm should be consulted prior to implementing remedial measures to observe the unstable subgrade conditions and provide appropriate recommendations. Krazan & Associates, Inc. Offices Serving The Western United States (l25 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 15 Drainn a and Landsea in The ground surface should slope away from building pads and pavement areas, toward appropriate drop inlets or other surface drainage devices. It is recommended that adjacent exterior grades be sloped a minimum of 2 percent for a minimutn distance of 5 feet away from structures. We recommend the installation of foundation drains with cleanouts for this project. The foundation drains should consist of a minimum 4-inch diameter perforated pipe, sloped to drain, with perforations placed near the bottom and enveloped by 6 inches of washed gravel in all directions and filter fabric to prevent the inigration of fines into the drains. Roof drains should be tightlined away from foundations to a suitable outlet. Roof drains should not be connected to the footing drains. Subgrade soils in pavement areas should be inclined at a minimum of 1 percent and drainage gradients should be maintained to carry all surface water to collection facilities, and suitable outlets. These grades should be maintained for the life of the development. Specific recommendations for and design of storm water disposal systems or septic disposal systems are beyond the scope of our services and should be prepared by other consultants that are familiar with design and discharge requirements. Utility Trench Backfill Utility trenches should be excavated according to accepted engineering practices following Occupational Safety and Health Administration (OSHA) standards, by a contractor experienced in such work. The responsibility for the safety of open trenches should be borne by the contractor. Traffic and vibration adjacent to trench walls should be minimized; cyclic wetting and drying of excavation side slopes should be avoided. Depending upon the location and depth of some utility trenches, groundwater flow into open excavations could be experienced, especially during or shortly following periods of precipitation. All utility trench backfill should consist of structural fill. Utility trench backfill placed in or adjacent to buildings and exterior slabs should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. The upper 5 feet of utility trench backfill placed in pavement areas should be compacted to at least 95 percent of the maximum dry density based on ASTM Test Method D1557. Below 5 feet, utility trench backfill in pavement areas should be compacted to at least 90 percent of the maximum dry density based on ASTM Test Method D1557. Pipe bedding should be in accordance with the pipe manufacturer's recommendations. The contractor is responsible for removing all water -sensitive soils from the trenches regardless of the backfill location and compaction requirements. The contractor should use appropriate equipment and methods to avoid damage to the utilities and/or structures during fill placement and compaction. Krazan & Associates, Inc. Offices Serving The Western United States AZV KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 16 Pavement Design The near -surface subgrade soils generally consist of sand with gravel. These soils are rated as fair to good for pavement subgrade material. We estimate that the subgrade will have a California Bearing Ratio (CBR) value of 12 and a modulus of subgrade reaction value of k = 200 pci, provided the subgrade is prepared in general accordance with our recommendations. Appropriate lab tests can be performed for confirmation of these recoimnendations when the pavement areas have been defined. Depending on the existing soil conditions, at the time of subgrade preparation, we recommend that, at a minimum, 12 inches of the existing subgrade material be moisture conditioned (as necessary) and compacted to prepare for the construction of pavement sections. The subgrade should be compacted to at least 95 percent of the maximum dry density as determined by ASTM Test Method D1557. In place density tests should be performed to verify proper moisture content and adequate compaction. The subgrade may be proof rolled in lieu of the in -place density tests, particularly if dense, native soils are observed. In this case, moisture conditioning and compaction work may not be required. Alternatively, if moisture sensitive subgrade soils prohibit the use of vibratory compaction, it may be necessary to remove disturbed soil and replace the disturbed materials with clean crushed rock fill. The recommended flexible and rigid pavement sections are based on design CBR and modulus of subgrade reaction (k) values that would be achieved, only following proper subgrade preparation. It should be noted that subgrade soils that are relatively high in silt or clay content may be highly sensitive to moisture conditions. The subgrade strength and performance characteristics of a silty or clayey subgrade material may be dramatically reduced if this material becomes wet. Traffic load information was not provided, however, based on our knowledge of the proposed project, we expect the traffic to be relatively light consisting mostly of passenger automobiles. For heavier traffic areas such as loading and unloading areas, as well as truck routes, we have provided heavy duty pavement sections. The following tables show the recommended pavement sections for light duty and heavy duty use. Krazan & Associates, Inc. Offices Serving The Western United States P2-7 KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 17 ASPHALTIC CONCRETE (FLEXIBLE) PAVEMENT LIGHT DUTY (PARKING AREA) - It Cilslte %r;' A _� r ate 33ase* .;:y;; C`-oii� actecl.ub rai[e* ** 2.0 in. 6.0 in. 12.0 in. * 95% compaction based on ASTM Test Method D1557 * * A proof roll may be performed in lieu of in place density tests ASPHALTIC CONCRETE (FLEXIBLE) PAVEMENT HEAVY DUTY (HEAVY TRUCK AREA) is haltic Contr6' ; r.�.. 'a ► "rc ati 3a c'� sC�in�acte 3.0 in. 6.0 in. 12.0 in. * 95% compaction based on ASTM Test Method D1557 * * A proof roll may be performed in lieu of in place density tests PORTLAND CEMENT CONCRETE (RIGID) PAVEMENT Minimum PC'(' ��nieQateBast C[�Irtt314t4d.SLib II 6.0 in. 1 6.0 in. 1 12.0 in. Y * 95% compaction based on ASTM Test Method D1557 ** A proof roll may be performed in lieu of in place density tests The asphaltic concrete depth in the flexible pavement tables should be a surface course type asphalt, such as Washington Department of Transportation (WSDOT) 1/ inch HMA. The rigid pavement design is based on a Portland Cement Concrete (PCC) mix that has a 28 day compressive strength of 4,000 pounds per square inch (psi). The design is also based on a concrete flexural strength or modulus of rupture of 550 psi. Testing and Inspection A representative of Krazan & Associates, Inc. should be present at the site during the earthwork activities to confirm that actual subsurface conditions are consistent with the exploratory fieldwork. This activity is an integral part of our services as acceptance of earthwork construction is dependent upon compaction testing and stability of the material. This representative can also verify that the intent of these recommendations is incorporated into the project design and construction. Krazan & Associates, Inc. will not be responsible for grades or staking, since this is the responsibility of the Prime Contractor. Furthermore, Krazan & Associates is not responsible for the contractor's procedures, methods, scheduling or management of the work site. Krazan & Associates, Inc. Offices Serving The Western United States KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 18 LIMITATIONS Geotechnical engineering is one of the newest divisions of Civil Engineering. This branch of Civil Engineering is constantly improving as new technologies and understanding of earth sciences improves. Although your site was analyzed using the most appropriate current techniques and methods, undoubtedly there will be substantial future improvements in this branch of engineering. In addition to improvements in the field of geotechnical engineering, physical changes in the site either due to excavation or fill placement, new agency regulations or possible changes in the proposed structure after the time of completion of the soils report may require the soils report to be professionally reviewed. In light of this, the owner should be aware that there is a practical limit to the usefulness of this report without critical review. Although the time limit for this review is strictly arbitrary, it is suggested that two years be considered a reasonable time for the usefulness of this report. Foundation and earthwork construction is characterized by the presence of a calculated risk that soil and groundwater conditions have been fully revealed by the original subsurface investigation. This risk is derived from the practical necessity of basing interpretations and design conclusions on Iimited sampling of the earth. our report, design conclusions and interpretations should not be construed as a warranty of the subsurface conditions. Actual subsurface conditions may differ, sometimes significantly, from those indicated in this report. The recommendations made in this report are based on the assumption that soil conditions do not vary significantly from those disclosed during our field investigation. The findings and conclusions of this report can be affected by the passage of time, such as seasonal weather conditions, manmade influences, such as construction on or adjacent to the site, natural events such as earthquakes, slope instability, flooding, or groundwater fluctuations. if any variations or undesirable conditions are encoimtered during construction, the geotechnical engineer should be notified so that supplemental recommendations can be made. The conclusions of this report are based on the information provided regarding the proposed construction. If the proposed construction is relocated or redesigned, the conclusions in this report may not be valid. The geotechnical engineer should be notified of any changes so that the recommendations can be reviewed and reevaluated. Misinterpretations of this report by other design team members can result in project delays and cost overruns. These risks can be reduced by having Krazan & Associates, Inc. involved with the design teams meetings and discussions after submitting the report. Krazan & Associates, Inc. should also be retained for reviewing pertinent elements of the design team's plans and specifications. Contractors can also misinterpret this report. To reduce this, risk Krazan & Associates. Inc. should participate in pre -bid and preconstruction meetings, and provide construction observations during the site work. This report is a geotechnical engineering investigation with the purpose of evaluating the soil conditions in terms of foundation. design. The scope of our services did not include any environmental site Krazan & Associates, Inc. Offices Serving The Western United States AIR KRAZAN & ASSOCIATES, INC. KA No. 062-16008 Proposed Dental Office DRAFT Federal Way, WA January 20, 2017 Page No. 19 assessment for the presence or absence of hazardous and/or toxic materials in the soil, groundwater or atmosphere, or the presence of wetlands. Any statements or absence of statements, in this report or on any soils log regarding odors, unusual or suspicious items, or conditions observed are strictly for descriptive purposes and are not intended to convey engineering judgment regarding potential hazardous and/or toxic assessments. The geotechnical information presented herein is based upon professional interpretation utilizing standard engineering practices and a degree of conservatism deemed proper for this project. It is not warranted that such information and interpretation cannot be superseded by future geotechnical developments. We emphasize that this report is valid for this project as outlined above, and should not be used for any other site. Our report is prepared for the exclusive use of our client. No other party may rely on the product of our services unless we agree in advance to such reliance in writing. If you have any questions, or if we may be of further assistance, please do not hesitate to contact our office at (425) 485-5519. Respectfully submitted, KRAZAN & ASSOCIATES, INC. JGL/MDR Krazan & Associates, Inc. Offices Serving The Western United States M3 Vicinity Map N (Not to Scale) �'s asr 4/ y 733R q'S7 1 ,16' ST Approximate Site Area S 344M Sr d R- 41 K 1/1 S 3567WST N N Northwest of S. 348th St. and 1st Ave. S. - Federal Way, WA Reference: The VMnity Map Is based on a USGS WpograpWo map thled, 'Poverty Bny Quadrangle - Washington - 75-MEnuto Sorlm, doled 2014. 1<raz;Cr1. & ASSOCIATES,INC. Federal Way Dental -Northwest of S. Mth St. and 1st Ave. S. -Federal Way, WA Date: November 2016 Project Number: 062 -16008 =Dr,wnBy. Figure 1 Not to scale N-3 k I Site Plan (Not to Scale) t t t Proposed i Building i i I i i i i i i i i i Approximate ► 10 U_I Roletancem SIto plan I. basod on a drawing proAdE4 by Cllenttitled, LEGENDTodoral Way. WA- CanCepl Slln Option 4," dated Seplember22, 2016. B-1 Number and Approximate I'�l Location of Krazan Soil Boring on 11-29-16. Federal Way Dental -Northwest of S. 348th St. and 1st Ave. S. -Federal Way, WA Date: November 2016 Project Number: 062-16008 Drawn By: NG Figure: 2 Not to scale MIL APPENDIX A FIELD INVESTIGATION AND LABORATORY TESTING Field Investigation The field investigation consisted of a surface reconnaissance and a subsurface exploration program. Two (2) geotechnical borings were drilled and sampled for the subsurface exploration at this site. The soil borings were completed on November 29, 2016 by a Krazan subcontractor utilizing a truck - mounted drill rig. The soil borings were advanced to depths ranging from about 21.5 to 31.5 feet below the existing ground surface. The approximate exploratory boring locations are shown on the Site Plan (Figure 2). The depths shown on the attached soil boring logs are from the existing ground surface at the time of our exploration. The drilled borings were advanced using a truck mounted, auger drilling rig. Soil samples were obtained by using the Standard Penetration Test (SPT) as described in ASTM Test Method D1586. The Standard Penetration Test and sampling method consists of driving a standard 2-inch outside -diameter, split barrel sampler into the subsoil with a 140-pound hammer free falling a vertical distance of 30 inches. The summation of hammer -blows required to drive the sampler the final 12-inches of an 18- inch sample interval is defined as the Standard Penetration Resistance, or N-value. The blow count is presented graphically on the boring logs in this appendix. ,The resistance, or "N" value, provides a measure of the relative density of granular soils or of the relative consistency of cohesive soils. The soils encountered were logged in the field during the subsurface exploration and, with supplementary laboratory test data, are described in accordance with the Unified Soil Classification System (USCS). All samples from the explorations were returned to our laboratory for evaluation. The logs of the soil borings along with the laboratory test results are presented in this appendix. Laboratory Testing The laboratory testing prograin was developed primarily to determine the index properties of the soils. Test results were used for soil classification and as criteria for determining the engineering suitability of the subsurface materials encountered. Sulfate testing was also conducted on near -surface soil samples. Test results from AM TEST, Inc. are included in this appendix. Krazan and Associates, I nc. Offices Serving The Western United States Soil Classification USCS Soil Classification Major Division Group Description Coarse- Grained Soils < 50% passes #200 sieve Gravel and Gravelly Soils < 50% coarse fraction passes #4 sieve Gravel (with little or no fines) GW Well -Graded Gravel GP Poorly Graded Gravel Gravel (with > 12% fines) GM Silty Gravel GC Clayey Gravel Sand and Sandy Solis > 50% coarse fraction passes #4 sieve Sand (with little or no fines) SW Well -Graded Sand SP Poorly Graded Sand Sand (with > 12% fines) SM Silty Sand SC Clayey Sand Fine- Grained Soils Silt and Clay Liquid Limit < 50 ML Slit CL Lean Clay OL Organic Silt and Clay (Low Plasticity) > 50% passes #200 sieve Silt and Clay Liquid Limit > 50 MH Inorganic Silt CH Inorganic Clay OH Organic Clay and Silt (Med. to High Plasticity) Highly Organic Soils PT Peat Relative Density with Respect to SPT N-Value Coarse -Grained Soils Fine -Grained Soils Density N-Value (Blows/Ft) Density N-Value (Blows/Ft) Very Loose 0-4 Very Soft 0-1 Loose 5 -10 Soft 2-4 Medium Dense 11 - 30 Medium Stiff 5-8 Dense 31 -50 Stiff 9 - 15 Very Dense > 50 Very Stiff 16 - 30 Hard > 30 KRAZAN AND ASSOCIATES, INC. 4303 - 998th St SW Lynnwood, WA x n w a LU Q U) 3 + . • .' : - •' MATERIAL DESCRIPTION Pavement Section 5-inches of asphalt and crushed gavel Fill Material . , Brown gravel with sand •" (medium dense to very dense, moist) 5 ■ • : _ - soil becomes wet Slit with Clay (ML) Gray silt with day and trace sand (very stiff, moist to wet) i5 - soil becomes silty clay (CL-ML) LOG OF EXPLORATORY BORING B-1 PROJECT: Federal Way Dental DATE: 11129116 PROJECT NO.: 062-16008 PAGE: 1 of 1 LOGGED BY: JLING SURFACE ELEVATION: CONTRACTOR: Geologic Drill BORING TYPE: Hollow Stem Auger SAMPLE METHOD: SPT - Split Spoon LOCATION: Federal Way, WA m z Natural Moisture N-VALUE (GRAPH) Content O wa N wi yr 3H Q o 2 (Percent) J m iv Q 10 20 30 40 10 20 30 40 m �: Z Nt-- 10 23 - soil becomes silt with clay (ML) End of Exploratory Boring 50 43 24 2e 23 Water Level Initial: Y Final: . Water Observations: Perched groundwater was encountered at a depth of approximately 11.0 feet below the ground surface. Notes: A216 LOG OF EXPLORATORY BORING B-2 KRAZAN AND ASSOCIATES, INC. 4303 -198th St SW PROJECT: Federal Way Dental DATE:11129116 Lynnwood, WA PROJECT NO.: 062-16006 PAGE:1 of 1 LOGGED BY: JLING SURFACE ELEVATION: CONTRACTOR. Geologic Drill BORING TYPE: Hollow Stem Auger SAMPLE METHOD: SPT - Split Spoon LOCATION: Federal Way, WA 'u ~ N-VALUE (GRAPH) Natural Moisture 3 �F Content MATERIAL DESCRIPTION COi ^, LU Z) w LU F w p Q o a. (Percent) w 3 m ° z y 10 20 30 40 1�0 200 40 o ..,.. Pavement Section 5-inches of asphalt and crushed gravel 4e 25 �1 .. •T. ` 23 .�-- Fill Material 7 4!i Brown gravel with sand i (medium dense to very dense, moist) 2s 49 2B :.. 43 i';1!ii7' !r "ser 1J 33 W. ►ti 7G 10 • 26 [R: 0. 15 '• _ -soil becomes wet 56 Silt with Clay (ML) 26 ! Gray silt with clay and trace sand (very stiff to hard, moist) 20 �l i b I -'M 30 1 I tg °-,`-` 21 >[ L ti k 30 I E 31 ; 1 End of Exploratory Boring Water Level Initial: $ Final: I Water Observations: Perched groundwater was encountered at a depth of approximately 15.0 feet below the ground surface. Notes: A3b Krazan & Assoc. Sieve Analysis 100 90 8D 70 IY- Z 60 IL Z 50 W � 40 w 30 20 10 U0 —.. 100 10 . GRAIN SIZE - mm. % Gravel % Sand % Fines Coarse Fine Coarse Medlum Fine slit Clay 0.0 20.9 40.4 7.0 13.3 13.4 5.0 Mater" Descri tlo Brown poorly graded gravel with silt and sand Atterherg Urnits (ASTM D 43181 PL= NP LL= NV PI= Classification USCS (D 2487)= GP -GM AASHTO (M 145)= A-1-a CoefFcients Dgp= 21 1612 DBS= 21.3207 D60= 14.0009 D50= 11.0690 D30= 1.5440 D95= 03358 D10= 0.2234 Cu= 62.67 Cc= 0.70 Remarks Natural Moisture Content (ASTM D-2216): 3.0% Date Received: 12/2/16 Date Tested: 12/5/16 Tested By: Ross Goff Checked By: Corbett Mercer Title: Lab Manager (no specification provided) Location: Boring 2 Date Sampled: 11/29/16 Samplee 7- 0' Y Client: Covenant Group Project: Proposed New Dental Office rpip,ct o: Fi ur �I��I�I�IY . ��1��16�Yu��lls��llp� Test Results (ASTM C-136 &ASTM C-117) Opening Percent Spec." Pass? Size Finer (Percent) (X=Fall) 1.25 100.0 1 92.4 .75 79.1 .5 55.0 .375 46.6 #4 38.7 #10 31.7 #20 26.0 #40 18.4 #60 11.1 #100 7.4 #200 5.0 A3-7 6( 5( 1( LIQUID AND PLASTIC LIMITS TEST REPORT r` Dashed line indicates the approximate r' upper limit boundary for natural soils O .• r r r rr ,r r`r i r r rr i i r r �r r r ` OAL rr Ge' r` rr r r ML or OL MH or OH L 0 0 l u xu au +u MATERIAL DESCRIPTION Light grayish -brown silty clay LIQUID LIMIT LL PL 27 15 Project No. 06216008 Client: Covenant Group Project: Proposed New Dental Office ■Location: Boring 1 Depth: 20' - 21.5' Sample Number: 57037-B _KXa M Tested By: Ross Goff Checked By: CorhPtt Mercer PI %<#40 %<#200 USCS 12 98.7 N/A CL Remarks: /Samale ID: 57037-B. S r Am Test Inc. 13600 NE 126TH PL Suite C Kirkland, WA 98034 (425) 885-1664 www.amtestiab.com x.. L A B O -HA T O H 1 E S ANALYSIS REPORT KRAZAN & ASSOCIATES, INC 4303- 198TH ST SW LYNNWOOD, WA 98036 Attention: JEFF LEAGUE Project Name: FEDERAL WAY DENTAL OFFICE PO Number: 06216008 All results reported on an as received basis. AMTEST Identification Number 16-AO29973 Client Identification 57037-A Sampling Date 11129/16, 08:00 Minerals [PARAMETER R1=sUl- . UNITSulfate < 10 ug/g AMTEST Identification Number 16-AO29974 Client Identification 57037-C Sampling Date 11129/16, 10:00 Minerals D.L. IMETHOD 10 EPA 300.0 PARAMETER RESULT UNITS jQ ID-L. Sulfate 1< 10 Jug/g _ 10 M Kathy Fu iel President 300.0 Professional Analytical Services Date Received: 12/06/16 Date Reported: 1/13/17 ANALYST I DATE JC 01/06/17 4rVALYST ] DATE JC 01/06/17 w Am Test Inc. Professional 13600 NE 126th PL Analytical Suite Services Kirkland, WA, 98034 (425) 885-1664 L A e o R A T O R I E S www.amtestiab.com QC Summary for sample numbers: 16-A029973 to 16-A029974 DUPLICATES SAMPLE # I ANALYTE UNITS SAMPLE VALUE I DUP VALUE _ _RPD 16-A029973 Sulfate ug/g < 10 < 10 STANDARD REFERENCE MATERIALS ANALYTE I UNITS TRUE VALUE MEASURED VALUE IRECOVERY Sulfate I ug/g 1200 1200 1100.% BLANKS ANALYTE JUNITS IRESULT Sulfate I ugig 1<10 APPENDIX B EARTHWORK SPECIFICATIONS GENERAL When the text of the report conflicts with the general specifications in this appendix, the recommendations in the report have precedence. SCOPE OF WORK: These specifications and applicable plans pertain to and include all earthwork associated with the site rough grading, including but not limited to the furnishing of all labor, tools, and equipment necessary for site clearing and grubbing, stripping, preparation of foundation materials for receiving fill, excavation, processing, placement and compaction of fill and backfill materials to the lines and grades shown on the project grading plans, and disposal of excess materials. PERFORMANCE: The Contractor shall be responsible for the satisfactory completion of all earthwork in accordance with the project plans and specifications. This work shall be inspected and tested by a representative of Krazan and Associates, Inc., hereinafter known as the Geotechnical Engineer and/or Testing Agency. Attainment of design grades when achieved shall be certified to by the project Civil Engineer. Both the Geotechnical Engineer and Civil Engineer are the Owner's representatives. If the contractor should fail to meet the technical or design requirements embodied in this document and on the applicable plans, he shall make the necessary readjustments until all work is deemed satisfactory as determined by both the Geotechnical Engineer and Civil Engineer. No deviation from these specifications shall be made except upon written approval of the Geotechnical Engineer, Civil Engineer or project Architect. No earthwork shall be performed without the physical presence or approval of the Geotechnical Engineer. The Contractor shall notify the Geotechnical Engineer at least 2 working days prior to the commencement of any aspect of the site earthwork. The Contractor agrees that he shall assume sole and complete responsibility for job site conditions during the course of construction of this project, including safety of all persons and property; that this requirement shall apply continuously aid not be limited to normal working hours; and that the Contractor shall defend, indemnify and hold the Owner and the Engineers harmless from any and all liability, real or alleged, in connection with the performance of work on this project, except for liability arising from the sole negligence of the Owner of the Engineers. TECHNICAL REQUIREMENTS: All compacted materials shall be densified to a density not less than 95 percent of maximum dry density as determined by ASTM Test Method D1557 as specified in the technical portion of the Geotechnical Engineering Report. The results of these tests and compliance with these specifications shall be the basis upon which satisfactory completion of work will be judged by the Geotechnical Engineer. Krazan and Assodates, I na. Offices Serving The Western United States �,L l SOIL AND FOUNDATION CONDITIONS: The Contractor is presumed to have visited the site and to have familiarized himself with existing site conditions and the contents of the data presented in the soil report. The Contractor shall make his own interpretation of the data contained in said report, and the Contractor shall not be relieved of liability under the contractor for any loss sustained as a result of any variance between conditions indicated by or deduced from said report and the actual conditions encountered during the progress of the work. DUST CONTROL: The work includes dust control as required for the alleviation or prevention of any dust nuisance on or about the site or the borrow area, or off -site if caused by the Contractor's operation either during the performance of the earthwork or resulting from the conditions in which the Contractor leaves the site. The Contractor shall assume all liability, including Court costs of codefendants, for all claims related to dust or windblown materials attributable to his work. SITE PREPARATION Site preparation shall consist of site clearing and grabbing and preparations of foundation materials for receiving fill. CLEARING AND GRUBBING: The Contractor shall accept the site in this present condition and shall demolish and/or remove from the area of designated project, earthwork all structures, both surface and subsurface, trees, brush, roots, debris, organic matter, and all other matter determined by the Geotechnical Engineer to be deleterious. Such materials shall become the property of the Contractor and shall be removed from the site. Tree root systems in proposed building areas should be removed to a minimum depth of 3 feet and to such an extent which would permit removal of all roots larger than 1 inch. Tree root removed in parking areas may be limited to the upper 1% feet of the ground surface. Backfill or tree root excavation should not be permitted until all exposed surfaces have been inspected and the Geotechnical Engineer is present for the proper control of backfill placement and compaction. Burning in areas, which are to receive fill materials, shall not be permitted. SUBGRADE PREPARATION: Surfaces to receive Structural fill shall be prepared as outlined above, excavated/scarified to a depth of 12 inches, moisture -conditioned as necessary, and compacted to 95 percent compaction. Loose and/or areas of disturbed soils shall be moisture conditioned and compacted to 95 percent compaction. All ruts, hummocks, or other uneven surface features shall be removed by surface grading prior to placement of any fill material. All areas which are to receive fill materials shall be approved by the Geotechnical Engineer prior to the placement of any of the fill material. EXCAVATION: All excavation shall be accomplished to the tolerance normally defined by the Civil Engineer as shown on the project grading plans. All over excavation below the grades specified shall be backfilled at the Contractor's expense and shall be compacted in accordance with the applicable technical requirements. FILL AND BACKFILL MATERIAL: No material shall be moved or compacted without the presence of the Geotechnical Engineer. Material from the required site excavation may be utilized for construction site fills provided prior approval is given by the Geotechnical Engineer. All materials Krazan and Assodates, I nc Offices Serving The Western United States �qZ utilized for constructing site fills shall be free from vegetable or other deleterious matter as determined by the Geotechnical Engineer. PLACEMENT, SPREADING AND COMPACTION: The placement and spreading of approved fill materials and the processing and compaction of approved fill and native materials shall be the responsibility of the Contractor. However, compaction of fill materials by flooding, ponding, or jetting shall not be permitted unless specifically approved by local code, as well as the Geotechnical Engineer. Both cut and fill shall be surface compacted to the satisfaction of the Geotechnical Engineer prior to final acceptance. SEASONAL LIMITS: No fill material shall be placed, spread, or rolled while it is frozen or thawing or during unfavorable wet weather conditions. When the work is interrupted by heavy rains, fill operations shall not be resumed until the Geotechnical Engineer indicates that the moisture content and density of previously placed fill are as specified. Krazan and Aswdates, I nc. Offices Serving The westem United States AtA3 APPENDIX C PAVEMENT SPECIFICATIONS 1. DEFINITIONS — The term "pavement" shall include asphalt concrete surfacing, untreated aggregate base, and aggregate subbase. The term "subgrade" is that portion of the area on which surfacing, base, or subbase is to be placed. 2. SCOPE OF WORK — This portion of the work shall include all labor, materials, tools and equipment necessary for and reasonable incidental to the completion of the pavement shown on the plans and as herein specified, except work specifically notes as "Work Not Included." 3. PREPARATION OF THE SUBGRADE — The Contractor shall prepare the surface of the various subgrades receiving subsequent pavement courses to the lines, grades, and dimensions given on the plans. The upper 12 inches of the soil subgrade beneath the pavement section shall be compacted to a minimum compaction of 95% of maximum dry density as determined by test method ASTM D1557. The finished subgrades shall be tested and approved by the Geotechnical Engineer prior to the placement of additional pavement of additional pavement courses. 4. AGGREGATE BASE — The aggregate base shall be spread and compacted on the prepared subgrade in conformity with the lines, grades, and dimensions shown on the plans. The aggregate base should conform to WSDOT Standard Specification for Crushed Surfacing Base Course or Top Course (Item 9-03.9(3)). The base material shall be compacted to a minimum compaction of 95% as determined by ASTM D 1557. Each layer of subbase shall be tested and approved by the Geotechnical Engineer prior to the placement of successive layers. 5. ASPHALTIC CONCRETE SURFACING — Asphaltic concrete surfacing shall consist of a mixture of mineral aggregate and paving grade asphalt, mixed at central mixing plant and spread and compacted on a prepared base in conformity with the lines, grades, and dimensions shown on the plans. The viscosity grade of the asphalt shall be AR4000. The mineral aggregate shall be WSDOT % inch Hot Mix Asphalt (HMA). The drying, proportioning, and mixing of the materials shall conform to WSDOT Specifications. The prime coat, spreading and compacting equipment, and spreading and compacting the mixture shall conform to WSDOT Specifications, with the exception that no surface course shall be placed when the atmospheric temperature is below 50 degrees F. The surfacing shall be rolled with combination steel - wheel and pneumatic rollers, as described in WSDOT Specifications. The surface course shall be placed with an approved self-propelled mechanical spreading and finishing machine. 6. TACK COAT — The tack (mixing type asphaltic emulsion) shall conform to and be applied in accordance with the requirements of WSDOT Specifications. Krazan and Associates, I na Offices Serving nie Western United States WLA _�1�azZ &ASSOCIATES, INC. GEOTECHNICAL ENGINEERING • ENVIRONMENTAL ENGINEERING CONSTRUCTION TESTING & INSPECTION July 20, 2017 Krazan File Number 062-16008 Covenant Group 2044 California Avenue Corona, CA 92881 Attention: Ms. Julie A. Margetich Email: Mar etichJ acificdentalservices.com Tel: (951) 582-5745 Reference: Geotechnical Engineering Addendum Letter Stormwater Infiltration Feasibility Proposed New Dental Office Parcel No. 415920-0715 SW Campus Drive & lst Avenue South Federal Way, WA Dear Ms. Margetich, This letter presents our geotechnical engineering opinions regarding stormwater runoff infiltration feasibility for the proposed new dental office to be located northwest of the intersection of SW Campus Drive and 1st Avenue South in Federal Way, Washington. Introduction It is our understanding that the City of Federal Way has requested information regarding the feasibility of on -site stormwater infiltration for this project location. We previously issued a geotechnical engineering report for the site titled, "Geotechnical Engineering Investigation — Proposed New Dental Office — Parcel No. 415920-0715 — SW Campus Drive and 11t Avenue South, Federal Way, Washington 98023," dated February 15, 2017. The scope of our additional services were outlined in our "Change Order No. 1 — Geotechnical Engineering Consultation Services — Proposed New Dental Office — Parcel No. 415920-0715 — SW Campus Drive & I` Avenue South, Federal Way, WA," dated July 20, 2017. Subsurface Conditions Our previous soil borings at the project site encountered gravel and sand fill material overlying native silt with clay soils. The gravel and sand fill was approximately 12 to 16 feet in depth at our boring locations, and interpreted to have been imported and compacted during previous earthwork construction. The native silt with clay soils were interpreted to have been deposited in an ancient lacustrine, or lake, environment. Offices Serving The Western United States 4303 —1981h Street SW, Lynnwood, WA98036 • (425) 485-5519; Fax (425) 485-6837 A4jA KRAZAN & ASSOCIATES, INC. KA Project No. 062-16008 Federal Way Dental Office Stormwater Infiltration Feasibility Letter July 20, 2017 Page No. 2 Groundwater seepage was encountered in our two soil borings from about 11 to 15 feet below the existing ground surface. Stormwater Infiltration Feasibili It is our opinion from a geotechnical standpoint that stormwater infiltration, including pervious pavement, is not feasible due to the presence of fill material overlying native silty and clayey soils. Fill materials can vary in texture and density, and therefore it is typically recommended that fill materials not be used as a medium for stormwater infiltration. We also referred to the "King County, Washington — Surface Water Design Manual," (KCWSWDM) (King County Department of Natural Resources and Parks, April 24, 2016), and the City of Federal Way stormwater manual titled, "Addendum to The King County Surface Water Design Manual," effective date January 8, 2017. The King County stormwater manual indicates that the bottom of infiltration facilities must be in native soil (ie. see Chapter 5, Sections 5.2.4.1 and 5.2.5.1). Accordingly, stormwater infiltration is not feasible at this site due to the fill materials encountered in our previous geotechnical explorations. Also, we understand that there is a subsurface stormwater vault adjacent to the site, and infiltration of stormwater on this site could have deleterious affects on the underground structure. Limitations This letter has been prepared for the exclusive use of our client and project representatives, for the specific application to the subject site. Our conclusions are based on the limited investigation of subsurface conditions at the subject site and on our interpretation of the current conditions only. If conditions are encountered that appear to be different than those described in this report, we should be notified so that we may review and verify or modify our recommendations. This letter does not include any environmental site assessment for the presence or absence of hazardous and/or toxic materials in the soil, groundwater or atmosphere, or the presence of wetlands or other biological conditions. The information presented herein is based upon professional interpretation using standard industry practices and engineering conservatism that we consider proper for this project. It is not warranted that such information and interpretation cannot be superseded by future geotechnical developments. 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 letter 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. Krazan & Associates, Inc. Offices Serving The Western United States M4 KRAZAN & ASSOCIATES, INC. KA Project No. 062-16008 Federal Way Dental Office Stormwater Infiltration Feasibility Letter July 20, 2017 Page No. 3 We appreciate the opportunity to provide this service for you. If you have any questions, or if we may be of further assistance, please do not hesitate to contact our office at (253) 939-2500. Respectfully submitted, KRAZAN & ASSOCIATES, INC. 07/20/17 ed Get I .Jeffrey G. League I Michael D. Rundquist, P.E. Jeffrey G. League, L.G. Senior Project Manager Project Geologist JGL:MDR Krazan & Associates, Inc. Offices Serving The Western United States A44 C V I CIO 1T� kAP r CD 14, �y O ty - p a to 0) _ i3 Gn +.�.. Mr, wF FT' N n r c � 8lik l: ti ff s D) z y e oil f. s, In n'Q -n, !Sr•..5r'4r: .�•.:1 rt 93 3..L :'t: 4 — i:. .'9SC i� .. — ..f,a F 11 s•'.y :i N 4T 1731• N 4P 17 21' N Soil Map —King County Area, Washington 5 ®� p �-O P kAT MIJ Mil l 0 =zQ 550150 550180 550240 RaN 5 pf! 4r 17' 31• N d�r�3:. �-r z'. +f .t max• _ jV i 40 ry A, 7 - r —10 Sol 55m 55M20 550150 550107 550210 55U40 3 fn a Map Scale, 1:1,506 if prt*!d m A portrait {8.5' x 11"y.4>eet. N r`rr — Meters O 20 40 so 120 O 50 100 200 300 hlap f ujectiai: Web Mercator Came-m mVnates: WG584 Edge tics: UTM Zone ION WGS84 Natural Resources Web Soil Survey c Conservation Service National Cooperative Soil Survey I-� L�6 4/6/2017 Page 1 of 3 Soil Map —King County Area, Washington Map Unit Legend King County Area, Washington (WA633) Map Unit Symbol Map Unit Name Acres In AOI L Percent of AOI EwC Everett-Alderwood gravelly 1.2 100.0% sandy loams, 6 to 15 percent slopes Totals for Area of Interest 1.2 100.0% tssraa Natural Resources Conservation Service Web Soil Survey National Cooperative Soil Survey 4/6/2017 Page 3 of 3 ALV7 gravelly coarse sand to very gravelly loamy sand. kieiepth to the IIC horizon ranges from 18 to 36 ches, Same areas are up to 5 percent included Alde oud so s, on the more rolling and undulating part' of the andscape; some are about 5 percent the d p, sand Indianola soils; and some 'are up to 25 arcent Neilt very gravelly loamy sands. Also in tided in map ng are areas where consolidated gl ia1 till, which c ractcristically underlies Alderw d soils, is at a pth of 5 to 15 feet, Pgrmea lity is rapid, The effectiv oorang depth is 6 inches or more. Available rater capac- ity is low, Runoff is slow, and the e sion hazard is slight, This soil - used for timber and asture and for urban developm t. Capability unit Vs-1; woodland group 3f3. sl Ev ,--7'ni soil is rot ng. Areas are i •eguiar in shape, avo a con x surface, and range from 25 acres to mor than 20 acres in size. Run- off is slow to medium, and t erosion hazard is slight to moderate. Soils included with i soil in mapping make up no more than 25 percent tlic total acreage. Some areas are up to 5 percen lderwood soils, which overlie consolidated gl, i till; some are up to 20 percent Neilton very, gra •lly loamy sand; and some are about 15 per at in 'uded areas of Everett soils where slopes ar more o tle than 5 percent and where they are s eeper the. 15 percent. This Everett soi is used f❑ timber and pasture and for urban dev pment. Capa 'lity unit VIs-1; woodland group 3f . 'his soil occurs as 1 , narrow areas, mostly long drainageways or ❑ short slopes between terr a benches, it is sim Ia to Everett gravelly sa y loam, 0 to 5 percent slo s, but in most place is stonier and more gravelly. Soils cluded with this soil in mappi make up no more an 30 percent of the total acres Some areas a up to 10 percent Aiderwood soils, hich overll consolidated glacial till; some are to 5 per" the deep, sandy Indianola soils; some re up t 10 percent Neilton very gravelly loamy s d; and ome are about 15 percent included areas of Ev ett soils where slopes are less than 15 perc 't, Runoff is medium to rapid, and the erosion haz d moderate to severe. Most of the acreage is used for timber, Capa- bility unit VIe-1; woodland group 3f2. Everett-Alderwood gravelly sandy loans, 6 to 15 percent slopes Lwc - s mapping unit is about equal parts •verett and Alderwood soils. The soils are rolling. Slopes are dominantly 6 to 10 percent, but range from gentle to steep, Most areas are irregular in shape and range from 15 to 100 acres or more in size. In areas classified as Everett soils, field examination and geologic maps indicate 16 the presence of a consolidated substratum at a depth of 7 to 20 feet. This substratum is the same mate- rial as that in the Alderwood soils. Some areas are up to 5 percent included Norma, Seattle, and Tukwila soils, all of which are poorly drained. Runoff is slow to medium, and the erosion hazard is slight to moderate, Most of the acreage is used for timber. Capabil- ity unit VIs-1; woodland group 3f3. 1 aSww.ss The Indianola series is made up of somewhat ex .ssively drained soils that formed under conifer in ndy, recessional, stratified glacial drift. The_ undulating, rolling, and hummocky soils ar on terra s. Slopes are 0 to 30 percent. The ann 1 pxecip tation is 30 to 55 inches, and the mean annual it temperature is about So' F. The fr st- free sea on is 150 to 210 days, Elevation x gas from abo sea level to 1,000 feet. In a r resentative profile, the upper inches is brown, rk yellowish -brown, and light live - brown loamy 'ine sand. This is underlai by olive sand that ex nds to a depth of 60 incl - or more (pl. I, right Indianola s 'ls are used for timb and for urban development. (I ITC) -This undul ing and roll .g soil 113 _ convex slopes. It is soar the edgos o upland terraces. Areas range from 5 t more tha 100 acres in size. Representative pro "le of dianola loamy fin© sand, 4 to 15 percent lopes in forest, 1,000 feet west and 900 feet sout of ie northeast corner of sec. 32, T. 25 N., R. 6 01--3/4 inch to 0, leaf ter. B21ir--0 to 6 inches, ow (10YR 4/3) loamy fine sand, brown (10 t 5/3 dry; massive; soft, very friable, nstick nonplastic; many roots; sligh, acid; c ar, smooth boundary. 4 to 8 inch e thick. B22ir--6 to 15 i es, dark yel wish -brown (10YR fi 4/4) loamy ne sand, brow (10YR 5/3) dry; massive; oft, very friable nonsticky, non - plastic, common roots; sligh acid; clear, smooth oundary, 6 to 15 in s thick. C1--15 to 3 inches, light olive-bro (2.5Y 5/4) loam fine sand, yellowish brol (10YR 6/4) dry fri massive; soft, very abl nonsticky, no lastic; common roots; slight acid; dual, smooth boundary. 12 to inches pick. C2-- to 60 inches, olive (5Y 5/4) sand, 'ght brownish gray (2,5Y 6/2) dry; single ain; loose, nonsticky, nonplastic; few roo slightly acid. Many feet thick. There is a thin, very dark brown Al horizon t the surface in some places. The B horizon rang r NLtD �LOOQ WWR4JCe 'RA�TE- M ,6rP PMa a IL T� wamm fu& iw c4nrwa wm SO00=1 OONIM DDW-ZBS (mg) ,uw� r.e snw �s�mmxoawa a�x .�r+; ••'•'�, a aY7 • ILOL6N0°J3H0'NHf1B000M NV'ld 30VNIVHO WH01S anN3AV ONVIOOOM •S OOb nd Lets- sasLa) "� ONV ONIOVHO rlIf1e-SV 'ONI '64003 OOMM ZZL9-ISL(SZ4/ Z� r � all vv- •tea Lmea vrniraH �N1 N i1. wWa Hinm .i.. •...4Ylrr�pewWr I.s irY !I.l.Wlr it `f 3 ! .22 _.co ed i 'y VJ W J ' 11 ,r tt3`i6 T-ir " iT �. .�.r r. w,. K .ii . ..i.ixIII slftn l3*� ........... •_.e. ...... aim.. LO 133H533S 3Nf1HO1VW �r r � �� we �w. - �Ae: VICINITY MAP n� Cc 3�6TH W w S 34M ST ON —SITE EXISTING CONDITIONS AREAS TOTAL AREA = 1.157 AC PERVIOUS AREA = 0.422 AC IMPERVIOUS AREA = 0.735 AC EX. PARKING/CURB(TO BE REMOVED) = 0.275 AC EX. PARKING/CURB(TO REMAIN) = 0.244 AC EX. SIDEWALK(TO BE REMOVED) = 0.019 AC EX. SIDEWALK(TO REMAIN) = 0.035 AC EX. DRIVE ISLE/CURB(TO REMAIN) = 0.162 AC ON —SITE PREDEVELOPED AREAS ROUTED TO DETENTION FACILITY TOTAL AREA = 0.294 AC PERVIOUS AREA = 0.294 AC (MODELED AS TILL FOREST) ON —SITE DEVELOPED AREAS ROUTED TO DETENTION FACILITY TOTAL AREA = 0.294 AC PERVIOUS AREA = 0.034 AC IMPERVIOUS AREA = 0.260 AC PROPOSED BUILDING ROOF AREA = 0.118 AC PROPOSED DRIVE THRU ISLE/CURB = 0.093 AC PROPOSED SIDEWALK = 0.040 AC PROPOSED DUMPSTER PAD/CURB = 0.009 AC FEDERAL WA Y COMMERCIAL (L OT B, NE 114, SE 114, SEC.19 TWN.21 N., RNG 4 E, W.M. PRE —DEVELOPED AND DEVELOPED BASIN MAP L7 LE m=235.82(B"N) LE.ou[=23572(B"5) * 20' STORM EASEMENT PER I AFN 20001109000600 !1 I k ! — 30' ACCESS EASEMENT LJ 7� -- i LOTH , !i ! PER AFN 20000510000678 / ) j ! 41 In t!------ ---- �..�----r �F�`--- �I ! 6EIWENT PER 20f1014B2 I .. _ D65TIHC FlRE___._ 1 HYDRANT I 1L U -� 15' STORM iA1KIROO T PER AFT 200011 p9ppp000 COVENANT REAL ESTATE GROUP PERMIT NO. APPROVED DATE 17000 RED HILL AVEHUE! IRVINE. CA 021141 714.845.8500 I I I 1 SCALE: 1'=40' I 10 20 40 80 � r r�.Yd1: Atr1J[' � ROME s �1 � , �f��wr,� , � I /�!y_• ECG `>f LE,-t=232.85(B'S) \� 10' OWE$T UTILITY EASEMENT PER 20 U410000311 i & 10' PSE 11nun EASEMENT 20000atooao3n LOT C 4159200720 i_lyg 4 60.50' \42 X", AREA TRIBUTARY TO TREA TMEN T VA UL T TOTAL AREA = 0.142 AC IMPERVIOUS AREA = 0.142 AC PROPOSED DRIVE THRU ISLE/CURB = 0.093 AC PROPOSED SIDEWALK = 0.040 AC PROPOSED DUMPSTER PAD/CURB = 0.009 AC pEyS10W q� VER77CAL DATUM KING COUNTY NGVD 29 BM: 1973 WSDOT BRASS DISK IN CONCRETE IN NORTH SHOULDER OF BRIDGE ON 320Ih ST ELEV.•454.96(NGVD 29) CONTOUR INTERVAL=2 TOPOGRAPHY PREPARED BY LARSON & ASSOCIATES PUBLISHED NAVD 88 ELEV- 458.51' SHIFT FROM NAVD BB TO NGVD 29= -3.55' (DERIVED FROM VERTCON) BASIS OFBEARINGS NAM 83/91 NORM ZONE LAND DESCRIPTION (pp CPWNOA1E1Tr FAQ mE' AYSWI!11'C � �y TgpppDp TLJLE pt(5VAVXE COAV WY AITM JULY 9, 2014,• COMM1TMFJVi NO. 0019576-08) LOT '8' OF CITY OF FEDERAL WAY BOUNCERY LINE ADJUSTMENT NO. 13-104768-00-SU, RECOROW UNDO? RCCOROW NUMBER 20TJ77Y49CW709, IN KING COUNTY, 9957ApIGTW LEGEND Ai: PROPERTY LINE --PI R/W LINE — — — EASEMENT LINE PROPOSED PAVEMENT EKF577NG SIDEWALK ® EXISTING STORM MANHOLE m b - DUS71NG STORM MAIN © EXISTING SANITARY SEWER MANHOLE -s-s- EXISTING SANITARY SEWER MAIN El EXISTING CATCH BASIN —Mwl— EXISTING POWER LINE (p EXISTING WATER VALVE b EXIS71NG FIRE HYDRANT -e EXISTING WATER MAIN —7W0— EXISTING TELEPHONE LINE Q Ews77NG TREE ENS77NG LIGHT POLE Y EXISTING SIGN EXISTING IRRIGA77ON METER EXISTING TV RISER ® EXISTING SIGNAL POLE m EXIS71NG JUNCTION BOX E FXIS71NG POWER VAULT ® EMS77NG PHONE RISER FMC EXIS77NG OIL/WATER SEPARATOR ® EXISTING PAVEMENT EXISTING RETAINING WALL ENIS77NG SIDEWALK PROPOSED SIDEWALK — s PROPOSED STORM MAIN as PROPOSED SANITARY SEWER SERVICE �w PROPOSED WATER SERVICE ■ PROPOSED STORM CATCHBASW PROPOSEDFlLTERRA VAULT R APPROVEED EQUAL 13 PROPOSED DCVA e PROPOSED RPBA IN 'HOT BOX' PROPOSED WATER METER A PROPOSED FDC (4- STORTZ) 5755 n0Z CL Q OLLJ 15 W W CL �LLJ n �L Q DATE 9-11-17 7RAWING NC 8755BASE b THE UNDERSIGNED HEREBY APPROVES THE ATTACHED (5) PAGES INCLUDING THE FOLLOWING: • PIPE STORAGE = 3,318 CF • MAINLINE PIPE GAGE = 16 • WALL TYPE = SOLID • DIAMETER = 96" • FINISH = ALT2 • CORRUGATION = 5x1 CUSTOMER DATE w p Am Wa.n.� �n",w,r. t.4-6. rM W.I.. -... -om— and eeN—W Leke(n kq—'v. 4.KN tM iCarue+ v Nembrl aa.ano nx.n, varr rnF..o- m+,- rti "un wrnesuna n.�aih.. r".n�mmm� rw.curuK Prbr.,.nr".b"inn CerOeN FMue ro mmpie ".."r• M In. u,"e� � mtn ruh i Cw.abe�eiYy E,i[lii"n .� hW.Av ar re.w�Mruky urc oe [cec v.w OncreQ.n-.n muu Fs • elf la rrrr��f:gn G bq Qeryn ne �Fwn mr yn.�ny w.e" r,. r�..and rru DATE I REVISION 30'-0" 15'-0" 36"0 RISER C1 SEE DETAIL SHEET C3 15'-0" 36"0 RISER D2 ASSFMRLY SCALE: 1" = b' L PIPE STORAGE: 3,318 CF./Gf LOADING: ;H2O de— [ Ay' PIPE INV. = 224.71'± CwNTECH" ENGINEERED SOLUTIONS LLC www.ContechES.com 11815 NE Glenn Widing Drive, Portland, OR 97220 800-548-4667 503-240-3393 800-561-1271 FAX w�l��u��wu• CMP DETENTION SYSTEMS CONTECH E ONTRACT DRAWING STUB INFORMATION PIECE STUB INVERT SYSTEM INVERT 6"0 STUB Al 231.71 224.71 8"0 STUB B1 225.21 224.71 RISER INFORMATION PIECE RIM ELEV. SYSTEM INVERT 36"0 RISER C1 237.7D 224.71 36"0 RISER D2 237.7D 224.71 NOTES • ALL RISER AND STUB DIMENSIONS ARETO CENTERLINE. • ALL ELEVATIONS, DIMENSIONS, AND LOCATIONS OF RISERS AND INLETS. SHALL BE VERIFIED BY THE ENGINEER OF RECORD (EOR) PRIOR TO RELEASING FOR FABRICATION. • ALL FITTINGS AND REINFORCEMENT COMPLY WITH ASTM A998. • ALL RISERS AND STUBS ARE 2%" xY2" CORRUGATION AND 16 GAGE UNLESS OTHERWISE NOTED. • RISERS TO IRE FIELD TRIMMED TO GRADE AS REQUIRED, BY CONTRACTOR. • QUANTITY OF PIPE SHOWN DOES NOT PROVIDE EXTRA PIPE FOR CONNECTING THE SYSTEM TO EXISTING PIPE OR DRAINAGE STRUCTURES. OUR SYSTEM AS DETAILED PROVIDES NOMINAL INLET ANDIOR OUTLET PIPE STUB FOR CONNECTION TO EXISTING DRAINAGE FACILITIES. IF ADDITIONAL PIPE IS NEEDED IT IS THE RESPONSIBILITY OF THE CONTRACTOR. • ALL ACCESS CASTINGS ARE THE RESPONSIBILITY OF THE CONTRACTOR AND ARE NOT SUPPLIED BY CONTECH. 96"0 UNDERGROUND DETENTION SYSTEM — 560567-020 FEDERAL WAY COMMERCIAL (LOT B) FEDERAL WAY, WA SITE DESIGNATION: DETENTION PRWECT N.. 560567 SEQ. N¢ DATE 020 6/29/2018 DE&ICWED. DUV DRAYM DUV cKECKaD PDW 'RO DUV SHEET NO_ C1 OF 5 d,. urele GwnRn F,npmva. ip er�avnn•]. •� any nwf rl Cpr.M1M1 Fal"rm we-r.ne.r rrcr.,re• e••••^9 •r ha.,d.rd q rW e+u+ nWoen �m.ewreh p 20 MIL PE IMPERMEABLE LINER OVER TOP OF PIPE LIMITS OF (IF REQUIRED) _ REQUIRED r BACKFILL 96" TYP. 36"" 2"ACKPILL0" SEE TYPICAL DETAIL NOTES TYPICAL SECTION VIEW NOT TO SCALE NOTE: IF SALTING AGENTS FOR SNOW AND ICE REMOVAL ARE USED ON OR NEAR THE PROJECT, A GEOMEMBRANE BARRIER IS RECOMMENDED WITH THE SYSTEM. THE GEOMEMBRANE LINER IS INTENDED TO HELP PROTECT THE SYSTEM FROM THE POTENTIAL ADVERSE EFFECTS THAT MAY RESULT FROM A CHANGE IN THE SURROUNDING ENVIRONMENT OVER A PERIOD OF TIME. PLEASE REFER TO THE CORRUGATED METAL PIPE DETENTION DESIGN GUIDE FOR ADDITIONAL INFORMATION. er..nv.• vn.u.. m..na. Km.�eee d uw,rr, e..wr.n.aae nrn.ax ar U-C rcrvcn� •kMmrM e�wn r mar es uwo revr"eka.. wits p IM1e prior xY.i COnia.[, �r s ply ee"e .t me ..pIa mm hw rra t�n•a anvllpW. u rrN••niP4ry Iw me .rwx•e "nem.aven.wn xnW I�•k :anfrw^r N. rh.w muxume. rye •o reoonen r er.aaraoan er ur eerpn. �en•;r• .1r:iY DATE REVISION DESCRIPTION BY qns u.w an w.mo•se.--...: - vb.•..>Imm� )RR. )FILE "X1 /4" 3'X1/2" . 5"X1" . 5"X1. BACKFILL REQUIREMENTS FOLLOW THE GUIDELINES OF AASHTO LRFD BRIDGE DESIGN (SEC 12) and CONSTRUCTION (SEC 26). kjMINIMUM TRENCH WIDTH MUST ALLOW ROOM FOR PROPER COMPACTION OF HAUNCH MATERIALS UNDER THE PIPE. THE MINIMUM TRENCH WIDTH (12.6.6.1): PIPE <_ 12": D + 16" PIPE > 12": 1.5D + 12" 1a MINIMUM EMBANKMENT WIDTH (in feet) FOR INITIAL FILL ENVELOPE (12.6.6.2): PIPE< 24": 3.OD PIPE 24" - 144": D + 4'0" PIPE > 144": D + 10'0" 2 THE FOUNDATION UNDER THE PIPE AND SIDE BACKFILL SHALL BE ADEQUATE TO SUPPORT THE LOADS ACTING UPON IT (26.5.2). L H PIPE --r 3 BEDDING MATERIAL SHALL BE A RELATIVELY LOOSE MATERIAL THAT IS ROUGHLY SHAPED TO FIT THE BOTTOM OF THE PIPE, AND A MINIMUM OF TWICE THE CORRUGATION DEPTH IN THICKNESS, WITH THE MAXIMUM PARTICLE SIZE OF ONE-HALF OF THE CORRUGATION PLAN DEPTH (26.3.8.1, 26.5.3). FRONT TYPICAL MANWAY DETAIL NOT TO SCALE 0NTEC H® ENGINEERED SOLUTIONS LLC www.ContechES.com 11815 NE Glenn Widing Drive, Portland, OR 97220 800-548-4667 563-240-3393 800-561-1271 FAX 4 CORRUGATED STEEL PIPE (CSP) [HEL-CORI. 5 HAUNCH ZONE MATERIAL SHALL BE HAND SHOVELED OR SHOVEL SLICED INTO PLACE TO ALLOW FOR PROPER COMPACTION (26.5.4). 5a INITIAL BACKFILL FOR PIPE EMBEDMENT TO MEETAASHTO A-1, A-2 OR A-3 CLASSIFICATION OR APPROVED EQUAL, COMPACTED TO 90% STANDARD PROCTOR (T-99). MAXIMUM PARTICLE SIZE NOT TO EXCEED 3" (12.4.1.2). ALL LIFTS PLACED IN A CONTROLLED MANNER. IT IS RECOMMENDED THAT LIFTS NOT EXCEED AN a" UNCOMPACTED LIFT HEIGHT TO PREVENT UNEVEN LOADING, AND THE LESSER OF 1/3 THE DIAMETER OR 24" AS THE MAXIMUM DIFFERENTIAL SIDE -TO -SIDE (26.5.4). 6 INITIAL BACKFILL ABOVE PIPE MAY INCLUDE ROAD BASE MATERIAL (AND RIGID PAVEMENT IF APPLICABLE), SEE TABLE ABOVE. 6a TOTAL HEIGHT OF COMPACTED COVER FOR CONVENTIONAL HIGHWAY LOADS IS MEASURED FROM TOP OF PIPE TO BOTTOM OF FLEXIBLE PAVEMENT OR TOP OF RIGID PAVEMENT (12.6.6.3). 7 FINAL BACKFILL MATERIAL SELECTION AND COMPACTION REQUIREMENTS SHALL FOLLOW THE PROJECT PLANS AND SPECIFICATIONS PER THE ENGINEER OF RECORD (26.5.4.1). NOTES: • GEOTEXTILE SHOULD BE CONSIDERED FOR USE TO PREVENT SOIL MIGRATION INTO VARYING SOIL TYPES (PROJECT ENGINEER). • FOR MULTIPLE BARREL INSTALLATIONS THE RECOMMENDED STANDARD SPACING BETWEEN PARALLEL PIPE RUNS SHALL BE PIPE DIA./2 BUT NO LESS THAN 12", OR 36" FOR PIPE DIAMETERS 72" AND LARGER. CONTACTYOUR CONTECH REPRESENTATIVE FOR NONSTANDARD SPACING (TABLE C12.6.7-1). w��l/�uT�lwu® CMP DETENTION SYSTEMS CONTECH CONTRACT DRAWNG TYPICAL BACKFILL DETAIL NOT TO SCALE 96" O UNDERGROUND DETENTION SYSTEM - 560567-020 FEDERAL WAY COMMERCIAL (LOT B) FEDERAL WAY, WA SITE DESIGNATION: DETENTION PROJECTNo- SEQ. Nq DATE 560567 020 6/29/2018 DESIGNED DRAWN DUV DUV -HECKED APPROVED'. PDW DUV SHEET NO n9 OF CONNECTION DETAIL 7 1/2" TECHCO SHOWN - MAY VARY TECHCO BAND ANGLES 112" DIA. BOLT RISER EXTENSION STUB HEIGHT 2'-0" RECOMMENDED V-0" MIN. FLAT BAND SHOWN, MAY VARY (NO GASKET) MAINLINE PIPE ELEVATION VIEW OF CMP & RISER PLAIN END CMP RISER PIPE GENERAL NOTES: 1. DELIVERED BAND STYLE AND FASTENER TYPE MAY VARY BY FABRICATION PLANT. 2. JOINT IS TO BE ASSEMBLED PER AASHTO BRIDGE CONSTRUCTION SPECIFICATION SEC 26.4.2.4. 3. BAND MATERIAL AND GAGE TO BE SAME AS RISER MATERIAL. 4. IF RISER HAS A HEIGHT OF COVER OF 10' OR MORE, USE A SLIP JOINT. 5. BANDS ARE NORMALLY FURNISHED AS FOLLOWS: 12" THRU 48" 1-PIECE 54" 2-PIECES 6. ALL RISER JOINT COMPONENTS WILL BE FIELD ASSEMBLED. 7. MANHOLE RISERS IN APPLICATIONS WHERE TRAFFIC LOADS ARE IMPOSED REQUIRE SPECIAL DESIGN CONSIDERATIONS. 8. DIMENSIONS SUBJECT TO MANUFACTURING TOLERANCES. in een lrgwme2 LWN�w tiC jCenoM'4 . xnp "f..rq oul+ncn,w nq ee u.fe ri >Cu,ee +n anY r.eev,er wvnvu[ rtie e"e1 vnlu •W�e le fanMlr � ea+e fi tn. wen inese vfvrnek dndylmr ry urwf r rey �n mufpfr,afr ONM'Sy�Af wv➢nea WpinoFo N.M� )h 6evdeneMwrner¢a.tlM1on wi eAv Myer pvye.effa vrax tlnfrppfr�e.n eiu Gnifrn umm�e¢ddr wr n-e•awmm�.r me en e �. rw �raae�we..� wka we,rwn I. mremypvn r,y.yp R W w. 12" RISER BAND DETAIL NOT TO SCALE d•� .em ►, Negrm fin tt awd yr kY1M r.a1i muw rw rp¢*.Arn fecovae otl h repMeO y, �r.ean "��"" AAR DATE REVISION DESCRIPTION BY C% NTECH® ENGINEERED SOLUTIONS LLC www.ContechES.com 11815 NE Glenn Widing Drive, Portland, OR 97220 800-548-4667 503-240-3393 80D-561-1271 FAX 'I�� Auo Y �� w r v- CMP DETENTION SYSTEMS CONTECH CONTRACT DRAW NG 25-1 /2" CONNECTION DETAIL 24" TECHCO CORRUGATED FLAT GASKET BA TECHCO BAND ANGLES 1Iil tl� I � I f 1/2" DIA BOLT 2 2/3"xl/2" RIVETED PIPE FLAT GASKET GENERAL NOTES: 1. BAND MATERIALS ANDIOR COATING CAN VARY BY LOCATION. CONTACT YOUR CONTECH REPRESENTATIVE FOR AVAILABILITY. 2. BANDS ARE SHAPED TO MATCH THE PIPE -ARCH WHEN APPLICABLE. 3. BANDS ARE NORMALLY FURNISHED AS FOLLOWS: 12" THRU 48" 1-PIECE • 54" THRU 96" 2-PIECES 102" THRU 144" 3-PIECES 4. BAND FASTENERS ARE ATTACHED WITH SPOT WELDS, RIVETS OR HAND WELDS. 5. ALL CMP IS REROLLED TO HAVE ANNULAR END CORRUGATIONS OF 2-2/3"x1/2" 6. DIMENSIONS ARE SUBJECT TO MANUFACTURING TOLERANCES. 7. ORDER SHALL DESIGNATE GASKET OPTION, IF REQUIRED (SEE DETAILS ABOVE). 10-C BAND DETAIL NOT TO SCALE 96" 0 UNDERGROUND DETENTION SYSTEM — 560567-020 FEDERAL WAY COMMERCIAL (LOT B) FEDERAL WAY, WA SITE DESIGNATION: DETENTION PROJECT No 5E0 No'. DATE 560567 020 6/29/2018 DESIGNED DRAWN DUV DUV CHECKED APPROVED PDW DUV SHEET NO C3 OF 5 TEMPORARY COVER FOR CONSTRUCTION LOADS HEIGHT OF COVER CONSTRUCTION LOADS FINISHED GRADE FOR TEMPORARY CONSTRUCTION VEHICLE LOADS, AN EXTRA AMOUNT OF COMPACTED COVER MAY BE REQUIRED OVER THE TOP OF THE PIPE. THE HEIGHT -OF -COVER SHALL MEET THE MINIMUM REQUIREMENTS SHOWN IN THE TABLE BELOW. THE USE OF HEAVY CONSTRUCTION EQUIPMENT NECESSITATES GREATER PROTECTION FOR THE PIPE THAN FINISHED GRADE COVER MINIMUMS FOR NORMAL HIGHWAY TRAFFIC. AXLE LOADS PIPE SPAN, (kips) INCHES 18-50 1 50-75 1 75-110 1 110-150 MINIMUM COVER (FT) 2.0 2.5 3.0 3.0 12-42 48-72 3.0 3.0 3.5 4.0 78-120 3.0 3.5 4.0 4.0 126-144 3.5 4.0 4.5 4.5 'MINIMUM COVER MAY VARY, DEPENDING ON LOCAL CONDITIONS. THE CONTRACTOR MUST PROVIDE THE ADDITIONAL COVER REQUIRED TO AVOID DAMAGE TO THE PIPE. MINIMUM COVER IS MEASURED FROM THE TOP OF THE PIPE TO THE TOP OF THE MAINTAINED CONSTRUCTION ROADWAY SURFACE. CONSTRUCTION LOADING DIAGRAM SCALE: N.T.S. `I SPECIFICATION FOR CORRUGATED STEEL PIPE -ALUMINIZED TYPE 2 STEEL SCOPE THIS SPECIFICATION COVERS THE MANUFACTURE AND INSTALLATION OF THE CORRUGATED STEEL PIPE (CSP) DETAILED IN THE PROJECT PLANS. MATERIAL s THE ALUMINIZED TYPE 2 STEEL COILS SHALL CONFORM TO THE APPLICABLE REQUIREMENTS OF AASHTO M274 OR ASTM A929. PIPE THE CSP SHALL BE MANUFACTURED IN ACCORDANCE WITH THE APPLICABLE REQUIREMENTS OF AASHTO M36 OR ASTM A760. THE PIPE SIZES, GAGES AND CORRUGATIONS SHALL BE AS SHOWN ON THE PROJECT PLANS. ALL FABRICATION OF THE PRODUCT SHALL OCCUR WITHIN THE UNITED STATES. p" ud Nxrf' p art} p.if � FaJyrc re �A HANDLING AND ASSEMBLY SHALL BE IN ACCORDANCE WITH RECOMMENDATIONS OF THE NATIONAL CORRUGATED STEEL PIPE ASSOCIATION (NCSPA) INSTALLATION A 036" MAX., HS-25 ACCESS CASTING WITH GRADE RINGS AS REQUIRED, TO SE PROVIDED AND INSTALLED BY CONTRACTOR. MAYBE TOP MOUNTED CMP (AS SHOWN) OR RECESSED. w PROTECTION RIMIFINtSHED _ SLAB GRADE ; _---_ _--_- _411 VARIES ~ GASKET MATERIAL 0 CMP RISER SUFFICIENT TO PREVENT [ �a SLAB FROM BEARING ON F o RISER TO BE PROVIDED BY a CONTRACTOR. 06 11" TYP. SECTION VIEW ACCESS CASTING NOT SUPPLIED BY CONTECH 0A OB #4 DIAGONAL TRIM #4 DIAGONAL TRIM fi ��BAR (TYP. 4 PLACES), - _ BAR (TYP. 4 PLACES), SEE NOTE 7. _ /� �� _- _ t SEE NOTE 7.�_ t---�{-----j' = =rt 2" COVER I : I I (TYP) L11 1 R, /'<� 1j 1 I l f /7,♦ -r--ak T j I1�- �- fi i�. / I ? OPENING IN r OPENING IN PROTECTION PROTECTION--==t1- - --_- ri^-- It---- SLAB FOR SLAB FOR I I ti ,/ I �' I CASTING CASTING II I II INTERRUPTED BAR REPLACEMENT, SEE NOTE 6. STANDARD STANDARD REINFORCING, REINFORCING, SEE TABLE SEE TABLE ROUND OPTION PLAN VIEW SHALL BE IN ACCORDANCE WITH AASHTO STANDARD SPECIFICATIONS FOR HIGHWAY BRIDGES, SECTION 26, DIVISION II OR ASTM A798 AND -IN CONFORMANCE WITH THE PROJECT PLANS AND SPECIFICATIONS. IF THERE ARE ANY INCONSISTENCIES OR CONFLICTS THE CONTRACTOR SHOULD DISCUSS AND RESOLVE WITH THE SITE ENGINEER. IT IS ALWAYS THE RESPONSIBILITY OF THE CONTRACTOR TO FOLLOW OSHA GUIDELINES FOR SAFE PRACTICES. MATERIAL SPECIFICATION SCALE: N.T.S. en 4wnrt � r1N. dr0ump a penpce "f-, w st fcartmn.-�. ie,wxm.. ww�nf 'P.M. �Obol . De ,nYC �.proCuceA er 4m. ery a ew ai ina u.era a." nq .,v ii.«a �nr try a ,.ywrua�n 'w ae wpw.v „ �r.,mmon.w..".rn ac,al A�tl xerNGprt� �, n v�wMaed e0�un ^uY Ve �npnN .ewer wa,�w.d pK AR DATE REVISION DESCRIPTION BY ""'°""�"""q°""�`� yvr a C oNTECH® ENGINEERED SOLUTIONS LLC wwW.ContechES.com 11815 NE Glenn Widing Drive, Portland, OR 97220 800-54B-4667 503-240-3393 800-561-1271 FAX 40-1-V i MW" CMP DETENTION SYSTEMS CONTECH CONTRACT DRAWING REINFORCING TABLE **BEARING 0 CMP A 08 REINFORCING PRESSURE RISER (PSF) 0 4 #5 @ 10" OCEW 2,540 24 4'x4' 26 #5 @ 10" OCEW 1,900 04,-6P' #5 @ 10" OCEW 2,260 30" 4=6" x4'-6" 32 #5 @ 9" OCEW 1,670 0 5' #5 @ 9" OCEW 2,060 36" 5' x 5' 38 #5 @ 8" OCEW 1.500 42 0 5'-6" 44 #5 @ 8" OCEW 1,490 6-6" x 5'-6rt #5 @ 8" OCEW 1.370 48° 0 6 50„ #5 @ 7" OCEW 1,210 6' x 6' #5 @ 7" OCEW 1.270 NOTES: 1. DESIGN IN ACCORDANCE WITH AASHTO, 17th EDITION AND ACI 350. 2. DESIGN LOAD HS25. 3. EARTH COVER = 1' MAX. 4. CONCRETE STRENGTH = 4,000 psi 5. REINFORCING STEEL = ASTM A615, GRADE 60. 6. PROVIDE ADDITIONAL REINFORCING AROUND OPENINGS EQUAL TO THE BARS INTERRUPTED, HALF EACH SIDE. ADDITIONAL BARS TO BE IN THE SAME PLANE. `"ASSUMED SOIL BEARING CAPACITY - II j i� j it I I II - / �II I r---IT---- y---� TI^----1 tF----- I- I I I It� II I Hr--ya-I+ tl1r--�H Q Ir hl I 11 fl ,il I IT �I� v� 7 I1 INTERRUPTED BAR I I REPLACEMENT, SEE NOTE 6. I li V II I .,e SQUARE OPTION PLAN VIEW 7. TRIM OPENING WITH DIAGONAL #4 BARS, EXTEND BARS A MINIMUM OF 12" BEYOND OPENING, BEND BARS AS REQUIRED TO MAINTAIN BAR COVER. 8. PROTECTION SLAB AND ALL MATERIALS TO BE PROVIDED AND INSTALLED BY CONTRACTOR. 9. DETAIL DESIGN BY DELTA ENGINEERS, ARCHITECTS AND LAND SURVEYORS, ENDWELL, NY. MANHOLE CAP DETAIL NOT TO SCALE 96" O UNDERGROUND DETENTION SYSTEM - 560567-020 FEDERAL WAY COMMERCIAL (LOT B) FEDERAL WAY, WA SITE DESIGNATION: DETENTION PRCJECTNo SEQ.No DATE 560567 020 6/29/2018 DESIGNED DRAWN DUV DUV CHECKED APPROVED PDW DUV OF 2Y2' ALL STEEL PER (#6) REBAR CAN BE CUT FLUSH ° ASTM A36 TO OUTSIDE OF RAIL (BAR LENGTH = 16%4') OR BAR CAN >- EXTEND BEYOND RAILYZ'+ - FABRICATION TOLERANCE: ±Y4' n FLAT BAR AND REBAR: MILL 3/S" TOLERANCE APPLIES TYP. 12" TYP./e' HOLE w/3/" REBAR RUNG, CENTER TO CENTER WELD REBAR TO RUNG ON RUNG SPACING `D OUTSIDE OF STEEL RAIL Li ° 2Y2" x %" FLAT BAR SIDE RAIL PLAN SIDE NOTES: 1, LADDERS CAN BE MADE IN 20'-0" STANDARD LENGTHS AND CUT TO FIT 2. ALL MATERIAL TO MEET ASTM A-36 3. LADDER TO BE HOT DIPPED GALVANIZED PER ASTM A-123 AFTER FABRICATION IS COMPLETE STANDARD LADDER DETAIL NOT TO SCALE PART NO. HALAGVL16 PROVIDE MINIMUM OF 4 ATTACHMENT ANGLES (2 ON EITHER SIDE OF LADDER RAIL) TO CONNECT LADDER TO RISER EXTENSION RISER w/ LADDER AND STEPS IF EXTENSION IS REQUIRED RISER w/ LADDER AND STEPS L5" x 3" x Y4" x 16" LONG ATV-0" SPACING. LONG LEG TO MAINLINE CMP PROJECT OUT. WELD TOP 1 _g AND BOTTOM OF 3" LEG TO EACH 2% x Yz, 5 x 1, 3 x 1, ETC. MAX. CORRUGATION CREST (THESE ANGLES SHOULD BE USED a17 FOR LARGER DIAMETER a MAINLINES WHERE ADDITIONAL STEPS ARE NEEDED) NOTE: THIS DRAWING IS INTENDED TO APPLY TO LADDERS INSTALLED IN RISERS HAVING A DIAMETER OF 30" OR LARGER. DUE TO SPACE CONSTRAINTS AND LIMITED ACCESSIBILITY, THE PRACTICALITY AND SUITABILITY OF UTILIZING RISERS SMALLER THAN 30" DIAMETER AND/OR INCORPORATING LADDERS IN THESE SMALLER DIAMETER RISERS SHOULD BE ADDRESSED BY THE OWNER AND PROJECT ENGINEER n<eapn nx wr.x�p w �mww w perne t A ane w�r�acer trr Cemeen Enpnrne6SC45e1�.n0+a LLC fCsrc-�ren". Reene� m.t vr.,.. w .e� .nr ae�l t+w.eel. mey ne "tss .rr..aveve a me0llina .. anY mtnnre rdneut ph, nnM Mnen tenon:0 CeMFch F�I,>-r [a comWy la/vn .l l�Fux�'l w�nik ME CoNeeh rt9rtarY/ nul.iinr.ny YaWy aletponetpdp, !a I. ercwwnna. Fvervrm e.e •>b Ne�nwion ypen x n.wv n wee .ne nani a.0 taveem...nr n.eenensa n WvxFM p�ep�etxt !n<k.rctrr►+ls.n mw 9a �rp[nN xcwed..�.mw+eNrlx iscalweeerllnrww" :,ae� a�crolt nehrasie ru eeetw..e an ".a,+ip r.oweu a AARN DATE I REVISION DESCRIPTION `NOTE: WHEN RISER EXTENSIONS ARE USED, THE PLANT SHOULD CUT 3" FROM THE SIDE RAILS AS SHOWN '3" FROM BOTTOM OF LADDER RAIL TO RISER JOINT '3" FROM TOP OF LADDER RAIL TO RISER JOINT O LADDER RAILS AND RUNGS (2) Y4" FILLET WELDS 1" LONG ATTACHMENT ANC MINIMUM OF 4 ANGLES P LADDER SECTION, (2 EACH SIDE LADDER) 6' MAX. SPACI VERTICAL 6" FROM RUNG TO RISER JOINT 6" FROM RUNG TO RISER JOINT SECTION A -A RISER LADDER DETAIL NOT TO SCALE C 'd-NTECH" ENGINEERED SOLUTIONS LLC www.ContechES.com 11815 NE Glenn Widing Drive, Portland, OR 97220 800-54&4667 503-240-3393 800-561-1271 FAX �I��u�wu® j" a FEW" CMP DETENTION SYSTEMS CONTECH CONTRACT DRAWING RISER NORMALLY CMP WITH 2z/3' x Y2" CORRUGATIONS (4) %fi' FILLET WELDS FROM EACH ANGLE TO CORRUGATION CREST (2 WELD EACH SIDE) 1-3"x3"xY/6' 5Yz" LONG (4) %6' FILLET WELDS FROM EACH ANGLE CORRUGA' CREST (2 WELDS EACH S (4) L3" x 3" x 3/16' 5Y'LONG (2) Y4' FILLET WELD; 1" LONG FROM EACH ANGLE TO LADDER RAIL LADDER RAILS PLAN RISER iD - _ --A (4) %6' FILLET WELDS - - FROM EACH ANGLE TO CORRUGATION CREST (2 WELDS EACH SIDE) LT' x3"X316" I 5Yz" LONG — _ 17 — - -------= J LADDER RAILS AND RUNGS 96" 0 UNDERGROUND DETENTION SYSTEM - 560567-020 FEDERAL WAY COMMERCIAL (LOT B) FEDERAL WAY, WA SITE DESIGNATION: DETENTION ELEVATION PROLE :T No SEq. No : DATE 560567 I 020 6/29/2018 DESIGNED DRAWN DUV DUV I CHECKED APPROVED PDW DUV SHEET NO: C5 DP 5