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DEF SUB1 APPROVED STM RESUB3 BLD2021-0116+Storm_Pump_Report ONLY+2.10.2022_9.35.04_AM+2673233•l: 17 July 9, 2019 Revised: 10/07/2019 Revised: 06/29/2021 Revised 02/08/2022 NAVIX SITE I CIVIL ►1 .m■!M-D Submitted to: City of Edmonds 7110 210th St SW Edmonds, WA 98026 Reviewed by: Jenelle Taflin, P.E., LEED AP Principal jtaflin@navixeng.com 11235 s.e. 6th street, suite 150 t 425.453.9501 bellevue, wa 98004 f 425.453.8208 navixeng.com a info@navixeng.com STORMWATER SITE PLAN Table of Contents PROJECTSITE MAP.................................................................................................................................3 PROJECTOVERVIEW...............................................................................................................................4 SITELOCATION...................................................................................................................................4 DESIGNCRITERIA................................................................................................................................5 EXISTING CONDITIONS AND HYDROLOGY.............................................................................................6 EXISTING CONDITIONS.......................................................................................................................6 EXISTING SITE HYDROLOGY................................................................................................................7 DEVELOPED CONDITIONS AND HYDROLOGY.........................................................................................9 DEVELOPED CONDITIONS...................................................................................................................9 DEVELOPED SITE HYDROLOGY...........................................................................................................9 MINIMUMREQUIREMENTS.................................................................................................................10 OFFSITE ANALYSIS REPORT..................................................................................................................15 OVERVIEW........................................................................................................................................15 DOWNSTREAM ANALYSIS................................................................................................................15 EXISTING IMPACTS AND CRITICAL AREAS........................................................................................22 POTENTIAL OFFSITE IMPACTS..........................................................................................................23 100-YEAR FLOOD/OVERFLOW CONDITION......................................................................................23 PERMANENT STORMWATER CONTROL PLAN......................................................................................24 ON -SITE STORMWATER BMPs..........................................................................................................24 HYDROLOGIC MODELING.................................................................................................................26 FLOWCONTROL SYSTEM.................................................................................................................28 CONVEYANCE SYSTEM ANALYSIS AND DESIGN...............................................................................29 OPERATION AND MAINTAINANCE...................................................................................................29 CSWPPP ANALYSIS AND DESIGN..........................................................................................................31 SPECIAL REPORTS AND STUDIES..........................................................................................................41 PERMITS...............................................................................................................................................41 APPENDIX: A— WWHM DATA AND OUTPUT B — OPERATION AND MAINTENANCE MANUAL C — GEOTECHNICAL ENGINEERING REPORT D — STORMWATER PUMP DESIGN INFORMATION NAVIX Anthology of Edmonds Page 2 STORMWATER SITE PLAN PROJECT SITE MAP 212TH STREET PVC IE 374.90 S _ I 1. �RSSTfm�r—�-- ox JE I I - .jjpf�E sD_ rn (9Asls of BEARINGS) I I �I wLL rcL g"' I i I arMM EASEMENT REND Pump from stormwater F r. -? • • • detention to TO D "101 4551- 90—� ,°.,�,,,.'- connection with existing A{vD CAP T C SSr � _.. (12/2) - - - - storm system ' I: R:LA , Intercept off -site :LDTA ,� 0,EAS%, . N0.77D41. I �, storm conveyance ! ` stem 5D s Y _ \ ® PROPOSED 6-FLOOR SENIOR LIVING FACILITY WITH 1 LEVEL 6'IE OUT I IV.. a Q - UNDERGROUND PARKING - -_ EO OrvDS212 LLC I FFE W 302.75 I•. 4A� o L__ LOADI RAMP CM WAi STAIRS, STAIRS IMPER1232D aPER •PIDGE•391.2 ] F •�� O LRIDGE•3956' S -11Er L O TSW CORNER CMU y;. ALL IS t.1'E. DFE, fff111 sToxAas /� Up, I.. CONCRETE WALLL - ' .- vA1N 8'CLMC N. v /✓ )WNHONES J•CLMC S. . SSOCIATICN SW CORNERS +�+ CONCRETE10* WALL 15 OF ONE !1 ��•-3r'•- [�'y C.U.—/ TRIB�ET WALL `I I M U ISM I RE AL wAv EL:3JJ.8)� N 33T°.ACLE SJ)5JL ormwater detention `�" 98i o< RI na _NG RCC 20{ ST 1pFf[pOPER9gI{/Y 6' F2 ELEV•3JJ 5J 29"I5Nl 02 1 CTRL STC 3)A A �N _9JJ5).296 1 E 12J2391.945RE A t2]239t 933 l vault in basement FCAP EMERALD 30591• FNCE °F CMU WALL .—STER ENCLOSURE AT CORNER DSSES ONE 52'E. I ------------------------- OF(C ER. CR 15R1 / ,- Figure 1: Project Site Map Re-route off -site conveyance to existing storm system Connection with existing it storm system I I I irs � 0 i Z n SSI hWZ "N Connection I.: ' with existing I N V storm system Total Project Area: 36,885 SF (0.847 acres) Total Proposed Hard Surfaces: 32,899 (0.756 acres) Proposed Pollution Generating Hard/Impervious Surface: 4,759 SF (0.109 acres) Proposed Pollution Generating Pervious Surface: 5,712 SF (0.131 acres) Existing Unmanaged Hard Surfaces: 0 SF (0.00 acres) Total Disturbed Area: 36,885 SF (0.847 acres) Average Slope: 8-25% Estimated Ultimate Infiltration Rate: % inch/hour to % inch/hour NRCS Soil Group: Alderwood-Urban Land Complex Soils (glacial till) Project Boundary Line For conveyance system details, please see the stormwater plans. For infiltration feasibility information, please see the geotechnical report (Appendix C). NAVIX Anthology of Edmonds Page 3 STORMWATER SITE PLAN PROJECT OVERVIEW The site is currently developed as a single -story building and parking lot (see Existing Conditions section below). Onsite stormwater outfalls to an existing storm sewer main in 72nd Avenue W, which ultimately outfalls to Halls Creek. The proposed development will consist of an approximately 161,308 GSF, 6-story 126 independent senior housing units on a 0.78-acre parcel located at 21200 72nd Avenue W in Edmonds, Washington. The project includes two driveway access points, a trash enclosure pad, landscaping areas, sidewalks, and utility connections. No existing unmanaged hard surfaces will remain. SITE LOCATION 21Oth Street Southwest A- Edmonds Public Works L, I ■ _ 212fh_Street SoutMyeit_ PROJECT "YF � SITE i WA 99 2151h Street Southwest Swedish w / r o Edmonds:31 a 2 �opd Help ort % j �y� n � � c � Figure 2: Project Location Location: 21200 72nd Ave W Edmonds, WA 98026 (Snohomish County) Section, Township, Range: NW 1/4, NW 1/4, SEC. 29, TOWNSHIP 27N, RANGE 04E, W.M. Parcel/Tax Lot: 00580700000401 Parcel Size: 0.78 acres Total Area of Disturbance: 0.847 acres City, County, State: Edmonds, Snohomish County, Washington Zoning: CG, General Commercial NAVIX Anthology of Edmonds Page 4 STORMWATER SITE PLAN DESIGN CRITERIA The stormwater management facilities have been designed in accordance with the 2017 City of Edmond's Stormwater Management Code, which utilizes the 2014 Stormwater Management Manual for Western Washington and the City of Edmonds Stormwater Addendum. This project will result in greater than 5,000 SF of new plus replaced hard surface; therefore, the site is classified as a Category 2 project site and shall comply with Minimum Requirements 1-9 of the City of Edmonds Stormwater Management Code. Table 1 below summarizes the City of Edmonds stormwater requirements. pl�w JURISDIOTONAL REQUIREMI' M 2-year: Reduce to % pre -developed duration 50-year: Match pre -developed Water Quality Volume: N/A Water Quality Flow Rate: Full 2-year release rate from the detention facility _ Downstream Analysis: X mile *All continuous modelling to be performed using the "Puget East 36" precipitation time series, available in WWHM2012 by using WS-DOT data TABLE 1: Jurisdictional Requirements NAVIX Anthology of Edmonds Page 5 STORMWATER SITE PLAN EXISTING CONDITIONS AND HYDROLOGY EXISTING CONDITIONS The site is currently comprised of an existing office building with an associated parking lot area and landscaping. It is bound to the north by 212th Street SW, to the east by 72nd Avenue W, to the south by an apartment complex, and to the west by a townhome development. There is existing storm drainage infrastructure on -site that runs west to east and conveys off -site stormwater from the Hyde Park Townhomes to the municipal conveyance system in 72nd Avenue West. See Figure 3 for the Existing Conditions Map. Sn.n SYY O K 3)v2 w SY CONC K 32]5] Mw Sn.e3 WnC K M31 ww Y cO.c K 17L30 [ 3Y conk K 3ri..w SE Ja roc it Sx3.m 5 -T- w r- —ao- I o-rl T Active storm pipe �R1` V _- _ol- c—_. conveys runoff from 21-2—TH"s-fs—W. 5 ss B5 es— i Hyde Park Townhomes LOT', rUwe C.N. WC EL AL Off -site storm conveyance from Hyde Park Townhomes to west n4 rt >LALL T� a.,w uoffi uwE nxT. O COwiCN •a ..„r I N.IrD« IDS ) i \NO VVS • �IAR[S p 3' CILC'wCK Tf LOT• P[C. r10 }Q x AD1x.•13DI]r PYr rrxM N-J/, 2� (SS.BN SG.) NO AY __!' r. it J,3e3 • ------ I 31111 Y � •'0.11 0 IOSS scn.a - .13• T s..r- .ri.3.sa' 7• AW ■ mAIIE as1ID � I.v _. Lm¢__._, _____• tl swu.r arol / e.r coucxrt� PASCr PAMV • PW4)IxYEIEASI i•.T L I IDS NM NDMNO NKEE� Existing pipe outfall connection to existing storm main I 1111!I 1 re B11 r B�,,, ©EAs�;a" � LOTS toil •oo CITY OI IDYONDi Rr�vawY CY /NOIIT►4T MT . s' do it Sx IS ILLC. NO`TTON101N a! Slum 3A W NA2] 2 ]' cCNC c.GCiVS ! 1}11•l A51 : '� W �a — u;. WwP3rt. CN0.09JPf • � •.... ,: I .. _ _ rCUM ]A" .[.Nt AND cAa •o AT Soar •. oxarx ggg Figure 3: Existing Conditions Map The property slopes from an approximate elevation of 384 feet at the northwest corner of the site to about 375 feet at the southeast corner of the site (survey). The site has slopes in the range of approximately 3-25%. Per the City of Edmonds GIS critical areas map the site contains areas of landslide and erosion hazards (Figure 7), most likely having to do with the existing sloped/retaining wall areas in those locations. A Geotechnical Engineering Report was prepared for this project by Terracon Consultants, Inc on December 20, 2018 (Appendix Q. Per the report, on -site soils are comprised of asphalt and concrete pavement with a gravel base course at the surface; silty sand with variable gravel content with NAVIX Anthology of Edmonds Page 6 STORMWATER SITE PLAN organics at 3.5'-7.5' below grade; sand with silt content and trace gravel (recessional glacial outwash) at 10'-13' below grade; and, silty sand and sandy silt with variable gravel content (glacial till) up to 26' below grade. Groundwater was encountered at 20.5 feet deep in one of four borings and was not encountered during or after drilling in the other three borings. There are no known surface water bodies in the immediate vicinity of the site including wetlands. A high-pressure gas line is located to the east of the project site within the 72nd Avenue West right-of- way, outside of the proposed development area. The site is zoned CG, General Commercial, and is within the Highway 99 Subarea Plan. EXISTING SITE HYDROLOGY Surface runoff from the existing site is collected in two catch basins located in the parking lot in the northern half of the site and is conveyed east to the existing municipal conveyance system in 72nd Avenue West. The site is in the Halls Creek Drainage Basin (Figure 4). The existing conditions survey prepared by Axis Survey and Mapping on January 19, 2018 indicates a stormwater drainage easement on the property that runs from the western edge of the site at its boundary with the Hyde Park Townhomes to the east. The easement encompasses a 12-inch storm conveyance pipe that originates from the Hyde Park Townhomes to the west and connects to the existing municipal conveyance system in 72nd Avenue West. This off -site storm conveyance system will be intercepted and rerouted north around the proposed development. NAVIX Anthology of Edmonds Page 7 STORMWATER SITE PLAN �1 Halls ■ PROJECTCrook f Westgate If Pond ITE as �RII ii � :i ■ �� ! � � a I. aQl� :rerf � '; I■i7- era IBC■ ■r�9i■ ,: ! �7�i111111�1111 ■�■ 1�01 �r� t 11 I I I�I�!� �. �p : =IIIIII L1Uw tin I on I logo �,.�� \ III ■� y■�.:r'�lS� r - .11■■ ■'�■ �■r1I1C oii1.111 w�A�f IE /t 1■-- ■MUM 111111 uuu� E �;,� , f ids �� w. !r r!.lrr e Oil. r'Ii■�C �Ir�l ■ .a �u `I� IN ZZ" •� =�� r rid ■ i ■LTI .• • v i7�, uuum ■.a �� iii � s� 1• CLake Figure 4: Watershed Map NAVIX Anthology of Edmonds Page 8 STORMWATER SITE PLAN DEVELOPED CONDITIONS AND HYDROLOGY DEVELOPED CONDITIONS The proposed project will consist of an approximately 161,308 GSF, 6-story 126 independent senior housing units on a 0.78-acre parcel located at 21200 72nd Avenue W in Edmonds, Washington. All existing on -site structures will be demolished. DEVELOPED SITE HYDROLOGY Stormwater runoff from newly created pervious and impervious surfaces will be collected and routed to an on -site stormwater management system consisting of an approximately 23,100 CF underground detention vault for flow control. Flow from the vault will be restricted to pre -development forested conditions in accordance with City of Edmonds stormwater requirements. The controlled -released runoff will discharge to the municipal conveyance system in 72nd Avenue West by means of a stormwater pump system. All stormwater runoff from hard surfaces on -site will be managed and no existing, unmanaged hard surfaces will remain. The total proposed non -pollution -generating impervious surface is approximately 0.603 acres, the proposed pervious areas is approximately 0.131 acres, and the proposed pollution -generating impervious area is 0.109 acres (4,759 sf). As the project is not creating 5,000 SF or more of pollution -generating hard surface (PGHS) or 0.75 acres or more of pollution -generating pervious surface (PGPS), water quality treatment is not required. Table 2, below, summarizes the threshold discharge areas, including off -site areas. Current Hard Surfaces 0.616 Proposed Hard Surfaces 0.712 New + Replaced PGPS 0.131 New + Replaced PGIS 0.109 New + Replaced PGHS 0.000 Effective Impervious Surface 0.712 Existing, Unmanaged Hard Surface to Remain 0.000 Disturbed Pervious Surface 0.228 Total Additional Hard Surfaces 0.096 Table 2: Threshold Discharge Areas NAVIX Anthology of Edmonds Page 9 STORMWATER SITE PLAN MINIMUM REQUIREMENTS Does the project result in 2,000 square feet, or greater, of new plus replaced hard surface area? OR Does the land disturbing activity total 7,000 square feet or greater? Yes I No Minimum Requirements No. I through 5 apply I Minimum Requirement No. ? applies Neat Question Does the project add 5.000 square feet or more of new plus replaced hard surfaces? OR Convert 0.75 acres or more of vegetation to lawn or landscaped areas? OR Convert 2.5 acres or more of native vegetation to pasture? Yes Is this a road related project? All Minimum Requirements apply to the new and replaced hard surfaces and converted vegetation areas. All Minimum Requirements apply to the new hard surfaces and converted vegetation areas. Yes No Does the project add 5,000 square feet or No more of new hard surfaces? Yes Do new hard surfaces add 50% or more to the existing hard surfaces within the project limits? No Figure 5- Minimum Requirements No additional requirements. NAVIX Anthology of Edmonds Page 10 STORMWATER SITE PLAN Minimum Requirement #1: Preparation of Stormwater Site Plans The City shall require a Stormwater Site Plan from all projects meeting the thresholds in ECDC 18.30.060.C. Stormwater Site Plans shall use site -appropriate development principles to retain native vegetation and minimize impervious surfaces to the extent feasible. Stormwater Site Plans shall be prepared in accordance with Chapter 3 of Volume 1 of the SWMMWW and the requirements in the Edmonds Stormwater Addendum. Response: A stormwater site plan that includes the design drawings and this report has been prepared for this development. The storm water site plan has been designed using site -appropriate development principles to meet City of Edmonds guidelines to the maximum extent feasible. Minimum Requirement #2: Construction Stormwater Pollution Prevention Plan (SWPPP) All development projects are responsible for preventing erosion and discharge of sediment and other pollutants into receiving waters. Compliance with this minimum requirement can be achieved for an individual site if the site is covered under Ecology's General NPDES Permit for Stormwater Discharges Associated with Construction Activities and fully implementing the requirements of that permit. A Construction SWPPP is required for all projects which a) result in 2,000 square feet or more of new plus replaced hard surface area, b) where a structure with an exterior hard surface area of at least 2,000 square feet is being demolished, c) which disturb 7,000 square feet or more of land, or d) when the site falls within the Earth Subsidence Landslide Hazard Area, Landslide Hazard Area or steep slope critical area. Response: A preliminary Construction SWPPP has been prepared and is included in the "CWWPP Analysis and Design" section of this report, below. A full Construction SWPPP report to be utilized by the contractor will be submitted with this permit submittal package as a separate document. Minimum Requirement #3: Source Control of Pollution All known, available and reasonable source control BMPs must be required for all projects approved by the City. Source control BMPs must be selected, designed, and maintained in accordance with Volume IV of the SWMMWW. Response: All known, available, and reasonable source control BMPs have been evaluated for applicability to this project. This includes, but is not limited to, Dust Control at Disturbed Land Areas, Landscaping and Lawn/Vegetation Management, and Maintenance of Stormwater Drainage and Treatment Systems. The trash area is located inside the building and shall comply with source control requirements. See MEP plans for more detail. NAVIX Anthology of Edmonds Page 11 STORMWATER SITE PLAN Minimum Requirement #4: Preservation of Natural Drainage Systems and Outfalls Natural drainage patterns shall be maintained, and discharges from the project site shall occur at the natural location, to the maximum extent practicable. The manner by which runoff is discharged from the project site must not cause a significant adverse impact to downstream receiving waters and down gradient properties. The discharge must have an identified overflow route that is safe and certain and leads to the ultimate outfall location (such as a receiving water or municipal drainage system). All outfalls require energy dissipation. To demonstrate compliance with this core requirement, all projects shall submit an off -site qualitative analysis. If an existing problem (or potential future problem after development) is identified, mitigation will be required to prevent worsening of that problem. A quantitative analysis may be required for any project deemed to need additional information or where the project proponent or the City determines that a quantitative analysis is necessary to evaluate the off -site impacts or the capacity of the conveyance system. Per the Edmond's Stormwater Addendum, existing upstream flows must be accommodated without causing erosion or flooding impacts. Upstream flows shall not be routed through the project's conveyance, treatment, or retention/detention systems, unless those systems are sized to control those flows. Upstream flows that are collected and routed through or around the site in a separate conveyance shall be dispersed at the downgradient property line, if feasible, or discharged at a project outfall (or outfalls) in a manner that does not violate the criteria below or cause the capacity of a conveyance system to be exceeded. Response: Natural drainage systems and outfalls will be maintained to the maximum extent feasible for the development of this site. Onsite stormwater will be collected in a new underground detention vault in the basement of the proposed building and routed to the existing municipal conveyance system in 72"d Ave W, to which stormwater runoff from the site is discharged in the pre -developed condition. In the proposed condition, the existing drainage path and connection to the existing system in 72" d Ave W will be maintained. Minimum Requirement #S: On -Site Stormwater Management On -site Stormwater Management BMPs are required in accordance with the following project thresholds, standards, and lists to infiltrate, disperse, and retain stormwater runoff on -site to the extent feasible without causing flooding or erosion impacts. Category 2 project sites that discharge directly or indirectly to the City's MS4 shall use On -Site Stormwater BMPs from List No.2 for all new plus replaced hard surfaces and land disturbed. Response: On -site stormwater management BMPs have been evaluated in accordance with the City of Edmonds stormwater code requirements and the project is electing to use the List No. 2 option for on -site stormwater BMPs selection. Please see the Permanent Stormwater Control Plan — On -Site Stormwater Management BMPs section of this report for more information. Minimum Requirement #6: Runoff Treatment The following require construction of stormwater treatment facilities: • Projects in which the total of pollution -generating hard surface (PGHS) is 5,000 square feet or more in a threshold discharge area of the project, or • Projects in which the total of pollution -generating pervious surfaces (PGPS) — not including permeable pavements — is 0.75 acres or more in a threshold discharge area, and from which there will be a surface discharge in a natural or man-made conveyance system from the site. NAVIX Anthology of Edmonds Page 12 STORMWATER SITE PLAN Response: The total proposed pollution -generating hard surface (PGHS) is 4,478 SF and the pollution - generating pervious surface (PGPS) consisting of lawn and landscaping area is 5,647 SF. Therefore, water quality treatment facilities are not required as the area thresholds have not been exceeded. Moreover, the proposed roof area is non -pollution generating as it will be a thermoplastic membrane (TPO) roof that eliminates the potential for metals leaching as specified on the architectural plans and project specifications. Also, rooftop mechanical equipment will be outfitted with internal spill containment. Upon completion of MEP plans, engineer will confirm spill containment of roof top mechanical equipment is specified. Minimum Requirement #7: Flow Control Flow control is required on projects meeting the thresholds summarized below to reduce the impacts of stormwater runoff from hard surfaces and land cover conversions. Standard Flow Control Requirement (applies to discharges directly or indirectly to the City's MS4, except for projects that meet the direct discharge requirements outlined in "a" above): Stormwater discharges shall match developed discharge durations to pre -developed durations for the range of pre -developed discharge rates from 50 percent of the 2-year peak flow up to the full 50-year peak flow. The pre -developed condition to be matched shall be a forested land cover. Response: Flow control will be provided by utilizing a detention vault located in the basement level. Stormwater runoff from the roof and from the ground -level paved and landscaped areas will be collected and routed to the detention vault prior to discharge to the storm drainage system located in 72"d Avenue W. The detention vault is sized to meet discharge requirements for the entire redevelopment area in accordance with the 2014 Stormwater Management Manual for Western Washington requirements utilizing continuous modelling with WWHM2012. The detained runoff will be conveyed to a stormwater pump that is configured to gradually release the detained runoff per the maximum allowed release rates ranging from the 2-year mitigated storm event to the 100-year mitigated storm event (the mitigated events are less than the pre -developed flows under forested conditions). The runoff will be pumped to an on -site manhole structure from where it will gravity discharge to the municipal conveyance system in 72nd Avenue W. In the event of a storm water pump failure, a gravity line from the pump structure to the on -site manhole structure will be provided as an emergency overflow route. Minimum Requirement #8: Wetlands Protection The requirements below apply only to projects whose stormwater discharges into a wetland, either directly or indirectly through a conveyance system. Response: This project does not discharge to a wetland. Minimum Requirement #9: Operation and Maintenance NAVIX Anthology of Edmonds Page 13 STORMWATER SITE PLAN An operation and maintenance manual that is consistent with the provisions in Volume I and Volume V of the SWMMWW is required for proposed Stormwater Treatment and Flow Control BMPs/facilities. The party (or parties) responsible for maintenance and operation shall be identified in the operation and maintenance manual. For private facilities approved by the City, a copy of the operation and maintenance manual shall be retained on -site or within reasonable access to the site and shall be transferred with the property to the new owner. For public facilities, a copy of the operation and maintenance manual shall be retained in the appropriate department. A log of maintenance activity that indicates what actions were taken shall be kept and be available for inspection. Response: An Operation and Maintenance Manual is included in Appendix 8 of this report. NAVIX Anthology of Edmonds Page 14 STORMWATER SITE PLAN OFFSITE ANALYSIS REPORT OVERVIEW The project site consists of one drainage sub basin which outfalls to Halls Creek. Approximately 0.25 miles downstream is the intersection of 216t" Street SW and 72 d Avenue W. See Figure 6, below. No emergency services are located along the flow path. Project Site Downstream Flow Path TOM, , rdr i c mile � downstream ! `. 4 --;location � r� , Figure 6: Downstream Analysis Path Outfall to Halls Creek DOWNSTREAM ANALYSIS A formal downstream analysis was completed in accordance with the City of Edmond's 2017 Stormwater Addendum. This analysis was conducted on March 7, 2019. The temperature was approximately 40 degrees and overcast. NAVIX Anthology of Edmonds Page 15 STORMWATER SITE PLAN # Picture Description %.Owl - View from the northwest side of the site looking east. 1 Drainage is conveyed east across the site to en- an o rate catch basin on the northeast P g side of the site. . q^ _ L , J Y View from the northeast side of the site looking east. 2 ,� I Drainage is conveyed east offsite where it s turns south to a manhole in the western- most drive lane of 72"d Ave W north of 213t' PI SW. NAVIX Anthology of Edmonds Page 16 STORMWATER SITE PLAN 3 View from the west side of 72" Ave W looking south. Drainage is conveyed south through a 36" concrete pipe to a manhole in the western- most drive lane of 72nd Ave W. View from the west side of 72nd Ave W looking south. Drainage is conveyed south through a 36" concrete pipe to a manhole in the western- most drive lane of 72nd Ave W near the southeast corner of the Edmonds Park and Ride. NAVIX Anthology of Edmonds Page 17 STORMWATER SITE PLAN T. View from the west side of 72nd Ave W t looking south. 5 Drainage is conveyed south through a 36" . concrete pipe to a manhole on the west side of 72nd Ave W. k' u Tip Y t 24 4� y View from the sidewalk on the west side of 72nd Ave W looking east. _: + fi •, Drainage is conveyed south through a 36" 6 concrete pipe to a manhole on 2161" St SW. NAVIX Anthology of Edmonds Page 18 STORMWATER SITE PLAN - � View from the southwest corner of the -- ' intersection of 72"d Ave W and 2161" St SW. 7 Drainage is conveyed east through a 36" pipe to a manhole east of the intersection of Highway 99 and 2161" St SW. Image Credit: Google Maps View from the intersection of Highway 99 and 2161" St SW looking northwest. 8 Drainage is conveyed to the southeast Catch Basin corner of the intersection of Highway 99 and 2121" St SW. Image Credit: Google Maps NAVIX Anthology of Edmonds Page 19 STORMWATER SITE PLAN View from southeast corner of Highway 99 and 2161h St SW looking east. 9 Drainage is conveyed east along 2161h St SW through a 36" concrete pipe to a manhole on the south side of 2121h St SW. View from the south side of 2161h St SW looking east. 10 Drainage is conveyed east along 2161h St SW through a 36" concrete pipe to a f manhole on the south side of 212th St SW. NAVIX Anthology of Edmonds Page 20 STORMWATER SITE PLAN g - View from the south side of 2121h St SW looking southeast. 11 Drainage is conveyed southeast to an outfall along Halls Creek v tM 1`A + R• iJ- View from the south side of the Interurban Trail looking south. 12 Drainage outfalls to Halls Creek. 1 •Y � Y J Y71 '' aYiltniG:M.ra_' J A' ••: .lfi11 Ask E iS.i _� NAVIX Anthology of Edmonds Page 21 STORMWATER SITE PLAN EXISTING IMPACTS AND CRITICAL AREAS Per the City's website, there is an existing erosion hazard area along the northern and western perimeters of the site, most likely having to do with the existing sloped/retaining wall areas in those locations. The existing retaining wall along the western property boundary will be maintained in the developed condition. The shorter, existing retaining wall in the southwest corner of the site will be removed and replaced by retaining via the building. The downstream storm drainage system within 0.25 miles of the project is adjacent to existing erosion hazards, but there are no known impacts or problems associated with the drainage system. See Figure 7 below for the critical areas map. Project dog I. i mile ✓nstream )cation Lo roo0Q 216TH ST SW i Figure 7- Critical Areas Map 5 u NAVIX Anthology of Edmonds Page 22 STORMWATER SITE PLAN POTENTIAL OFFSITE IMPACTS The proposed on -site stormwater management system will be designed according to the 2017 City of Edmonds Stormwater Management Code. No impacts to groundwater, surface waters, or drainage patterns are anticipated. 100-YEAR FLOOD/OVERFLOW CONDITION The stormwater conveyance system for this project has been designed to address all storm events, including the 100-year, 24-hour storm, in accordance with common industry practices. Please see FIRM map shown in Figure 8 below. The project site is in Zone X, which is outside the 500-year floodplain. EL EN + 71 vn Project Site N /I : Y L s I it4 J i-- JT I J I'„ I � IV� � �I � r rw R suu'e Pnt6k m I e; y FIRM 9BOO L 00 :NSURA U 9AiC RP (11A Sal is LN'CY, 7,AlHINGTON MND II � NCOFtI'6RATPu➢ WFAB yy II PAN[L IT5 OF 151S 51 � �� III �� HA Lmacq PPP sacn'tau E ' t RO;'rrCC @C G fE. ifi;OfP ': I'YS I Figure 8: FIRM Map NAVIX Anthology of Edmonds Page 23 STORMWATER SITE PLAN PERMANENT STORMWATER CONTROL PLAN ON -SITE STORMWATER BMPs This project is electing to use the List No. 2 option for selection of on -site stormwater BMPs. After evaluating the stormwater BMPs provided in the City of Edmond's Stormwater Addendum for applicability to this project site, it has been determined that a stormwater detention vault is required for on -site stormwater flow control. A vault has been sized using the Western Washington Hydrology Model (WWHM) per City of Edmonds requirements (using WSDOT data) and a report has been generated through the WWHM software (Appendix A). Based on the Geotechnical Engineering Report by Terracon Consultants (Appendix C), the on -site soils were evaluated for infiltration potential and sieve analyses were performed to estimate an infiltration rate. The glacial till soils observed exhibited an appreciable fines content and the soils were dense to very dense. The geotechnical engineer concluded that the site is not suitable for infiltration and, therefore, stormwater management via infiltration is not recommended. The following tables list the evaluated on -site BMPs and reasons for infeasibility based on the 2017 City of Edmonds Stormwater Management Code, Appendix A. Post -Construction Soil Quality and Depth Yes On -site disturbed areas that result in lawn or landscaping will be amended with compost or replaced with topsoil meeting Post -Construction Soil Quality and Depth requirements. Full Dispersion No A minimum forested or native vegetation flow path length of 100 feet (25 feet for sheet flow from a non-native pervious surface) cannot be achieved due to the nature of the zero -lot line development. Downspout Full No The site does not have outwash or loam soils. Infiltration Geotechnical investigation does not recommend infiltration on this site. Systems Bioretention or No Geotechnical investigation does not recommend infiltration on this site. Rain Gardens Downspout No For splash blocks, a vegetated flow path of at least 50 feet in length from the Dispersion downspout to the downstream property line, structure, stream, wetland, Systems slope over 15 percent, or other impervious surface is not feasible due to the nature of the zero -lot line development. For trenches, a vegetated flow path of at least 25 feet between the outlet of the trench and any property line, structure, stream, wetland, or impervious surface is not feasible due to the nature of the zero -lot line development. Perforated Stub- No There is not at least 1 foot of permeable soil from the proposed bottom of the Out Connections perforated stub -out connection trench to the highest estimated groundwater NAVIX Anthology of Edmonds Page 24 STORMWATER SITE PLAN table or other impermeable layer. Geotechnical investigation shows no permeable soils on site. Detention Vaults Yes A detention vault has been sized using WWHM 2012 (Appendix A). and Pipes I -a 0 Full Dispersion No A minimum forested or native vegetation flow path length of 100 feet ( 55 feet for sheet flow from a nonnative pervious surface) cannot be achieved due to the nature of the zero -lot line development. Permeable No Not feasible at multi -level parking garages such as this. Pavement Geotechnical investigation does not recommend infiltration on this site. Bioretention or No Geotechnical investigation does not recommend infiltration on this site. Rain Gardens Sheet Flow No For flat to moderately sloped areas, at least a 10-foot-wide vegetation buffer Dispersion for dispersion of the adjacent 20 feet of contributing surface cannot be achieved. Concentrated Flow No A minimum 3-foot length of rock pad and 50-foot flow path OR a dispersion Dispersion trench and 25-foot flow path for every 700 sq. ft. of drainage area (within applicable setbacks) cannot be achieved. Detention Vaults Yes A detention vault has been sized using WWHM 2012 (Appendix A). and Pipes NAVIX Anthology of Edmonds Page 25 STORMWATER SITE PLAN HYDROLOGIC MODELING The hydrologic analysis for this project was performed using Western Washington Hydrology Model (WWHM2012), based on matching flow durations. MGS rainfall data was used to model the site runoff and size the stormwater facility. The following table summarizes the surface area of the existing site conditions as inputted into WWHM. Basin Area (AC) Description :E Soil Type C, Forest Table 3: Pre -Developed Condition The following tables summarize the tributary areas to the proposed detention vault as well as the bypass area of the developed conditions as inputted to WWHM. •mcm 0.131 Soil Type C, Lawn Flat 0.603 Rooftops Flat 0.087 Sidewalks/Driveways Flat Table 4: Tributary Area to Vault in Developed Condition .. M. 0.004 Soil Type C, Lawn Flat 0.022 Sidewalks/Driveways Flat Table 5: Bypass Area in Developed Condition Figure 9, below, shows the predeveloped forested condition as inputted in WWHM. NAVIX Anthology of Edmonds Page 26 STORMWATER SITE PLAN EVYjyI aT w CONCRETE U, L (BASIS OF BEAPoNGS) 4-c- SS -I 1 .T DOWN OI IBM A CAS nL 9' PVC IE IS SS 55 SS 1Y SS SS SS SS 55 SS Q IO'x10PE D n Mt1 G G FGL Ali ��Y EASEMENT _ �__ REC. N0. J9{0]Ot022{. G � G c REC. N0. 20t902t40t57 - _ _ _ _ - REC NO 2 POUND TO CAP N 'RA ass A coRNEr I � N 02/2ota. SOPHIA B nW CORNER CV I >' WALL IS 1,3E. 1 I !1 oI { Uhi 200. 97 HUNG I CNEry ETT AL, qL. O \� f 'I PB{OJ - )NP$tE� C UT I ED40NO521I IC I., E L _ O II ,01 --- CMU WALL IAL IMPERIAL PRLL' I L-- O Sw- CORNER C4U-- u WALL IS I.IE OF UNE. i WALL-- •\ CCNCPEIE .. 1N B'CL.0 N. I �- 3WNNONE5 ]'CIiNC S SSOCIATON - CORNERS CONCRETE WALL 4 'S" I IS TO'W OF UNE ' 00'J C4U WALL J y.� TIMBER RET WALL \II I L TIE 20 /I I1J3J, (LEyV�JJ].BJ T q O ED QN $ �E OS LNG{{98 L wa 1HST rvROPER r�ORNf RI 3J4 �// Al 6' 4P JJ2 4 ,j u I /e04� V+CC J]).e) N 29Jf5J.302 IL E 12]219t,9N LJ qC N]ES•� Q� pd� p�j T� CTRL STC JJ4 4 J/ POU D 5/ REB 4 O H 297757.296 IE t272391, S 13 10' POWER LINE EASEMENT REC. PgRB 212 ARi LLC a 'EMERALD CORNER A 0( f CE OF CMU WALL �ossEs DUMPSTER ENCLOSURE "-----""----"'--- NO 20161005052`� (t2/2016) I \ LINE 5.2'E. I OFcoRNER. -_ __ PREDEVELOPED AREA: --------- ------ -- _____ - FORESTED = 36,885 SF (0.847 AC) R1M717205 __- S- Pk IE 3JI.09 N i j-1 \ __________________________ I 9 Figure 9: Predeveloped Forested Condition Figure 10, below, shows the on -site, non -pollution generating impervious surfaces (NPGIS), pollution generating impervious surfaces (PGIS), and pervious surfaces as inputted into WWHM. NAVIX Anthology of Edmonds Page 27 STORMWATER SITE PLAN �.SBR.,58 * , 212TH STREET SW T T r — _ T r r PK IE S)<,90 s �D-wLL FOUND'%' J�'./E mO ,, ', - IT-- BRAss DISol,% RCe ,r °' 50— ( .�„s s CONCRErE `(t1 �- - ru 8- — IE 3 81 T / �l 1 rBM A <55 SS-3~ ss 55 55 s E5 55 55 SS 89 o S 0510'NIO'PED n WLL FCL � I IJtn M FAc,FYF•1>• sWJ010224. G G G G 0 kk A(1D CAP 'RNA 8551 AT CORNER _ ,• - "` I IO SOPHIA BI WING nW CORNER I OF IS T]'E. OF oI 200 291 121; HUNG CHUN -EN ET AL. \ ® PROPOSED 6-FLOOR MM 391.0T v 0 SENIOR LIVING FACILITY ROLRTE— WITH 1-LEVEL Q UNDERGROUND PARKING —I EDMOND5212 LLC FFE w 3B2,15 TRASH }n eL - C: eeee \\ g zf 91 LOADING / .OAMP1 OIU WALL •• STAIRS / \\ STAIRS N^ IMPERIAL PROPERT ;�. -,• I U 23W LLC I.' L SW CORNEA CMU— WALL 15 TI'E, O ONE. e CONCRETE WALL Ro9N M1H 8'CLFNC N- �wNRDMEs 3aFNc s. - SSotlA- - AON sw CORNER ' CONCRETE WALL - - -- No WALL - - TIMBER REr WALL-" - - - Y (� TRIBUTARY AREA TO VAULT: BYPASS AREA: �W HMI Rcc 201 ro'• EcwJ"-B'J ` ROOF = 26,227 (0.603 AC) IMPERVIOUS = 960 (0.022 AC) 291151.298 t212391.9J3 IMPERVIOUS = 3,799 (0.087 AC) PERVIOUS = 187 (0.004 AC) E FAcE o< wu wALL,_ t OSSEl LINE 5.21E PERVIOUS = 5,712 (0.131 AC) Oi CdWER. Figure 10: WWHM Tributary and Bypass Areas FLOW CONTROL SYSTEM The proposed flow control facility was designed in accordance with the 2014 Amendment to the 2012 Stormwater Manual for Western Washington and the 2017 City of Edmonds Stormwater Code. Pre - developed conditions are modeled as forested for all areas within the limits of disturbance. WWHM 2012 was used for flow control calculations. The detention vault is required to be 40 feet wide by 55 feet long by 10 feet deep. The proposed detention vault will be 42 feet wide (to account for column penetrations into the vault area) by 55 feet long by 10 feet deep. Basin data and results from the WWHM 2012 model are provided in Appendix A. The detained runoff will be conveyed to a stormwater pump that is configured to gradually release the detained runoff per the maximum allowed release rates ranging from the 2-year mitigated storm event to the 100-year mitigated storm event (the mitigated events are less than the pre -developed flows under forested conditions). NAVIX Anthology of Edmonds Page 28 STORMWATER SITE PLAN The first pump will discharge at a rate of 4 GPM, which is roughly equivalent to the 2-year mitigated flow of 0.009107 cfs as shown in the WWHM output and pump package discharge rates in the snapshots below. Similarly, the second pump will discharge at 10 gpm, roughly equivalent to the 25- year mitigated flow Of 0.023035 cfs. Finally, the third pump will discharge at 16 gpm, which is roughly equivalent to the 100-year flow of 0.034782 cfs. The elevations of the pumps match the bottom, middle, and top of live storage in the vault. Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.009107 5 year 0.013417 10 year 0.017144 25 year 0.023035 50 year 0.028418 100 year 0.034782 PUMP PACKAGE CONFIGURATION: TRIPLEX MODEL: ZOELLER N211 HP: 4/10HP DUTY POINT: 4GPM @ 363.25' 10GPM @ 368.0' 16GPM @ 372.75' Discharge from the site will be gradual over a range of flows and complies with the design intent and requirements. Please see Appendix D for the pump design information from the pump supplier. The runoff will be pumped to an on -site manhole structure from where it will gravity discharge to the municipal conveyance system in 72nd Avenue W. In the event of a stormwater pump failure, a gravity line from the pump structure to the on -site manhole structure will be provided as an emergency overflow route. CONVEYANCE SYSTEM ANALYSIS AND DESIGN The site conveys stormwater runoff through 6-inch, 8-inch, and 12-inch diameter conveyance pipes at a minimum slope of 1.0%. As shown in the Manning's Calculations in Figure 11 below, the max. flow rate for a 6-inch storm drainage pipe at a min. slope of 1.0% is 0.5626 cfs. The max. flow rate for an 8-inch storm drainage pipe at a min. slope of 1.0% is 1.2117 cfs. The max. flow rate for a 12- inch storm drainage pipe at a min. slope of 1.0% is 3.5724 cfs. All of which are greater than the 100- year peak flow event from the developed site of 0.034 cfs. NAVIX Anthology of Edmonds Page 29 STORMWATER SITE PLAN Diameter (in) 6 Diameter (in) 8 Diameter (in) 12 Manning's n 0.013 Manning'::: n 0.013 F,4anning's n 0.013 Slope 1%) 1 Slope (%) 1 ;lope (%) 1 Flow (cis) .037 Flow (cfs) .037 Flow (cis) .037 Full Q (cfs) 0.5626 Full Q (cfs) 1.2117 Full Q (cfs) 3.5724 Full Vel (fps) 2.8654 Full Vel (fps) 3.4712 Full Vel (fps) 4.5485 Velocity (fps) 1.6228 Velocity (fps) 1.5546 Velocity (fps) 1.4859 Hyd Radius 0.0531 Hyd Radius 0.0503 Hyd Radius 0.046 Normal Depth (it) 0.0868 Normal Depth (ft) 0.0800 Normal CIF-pth (ft) 0.0714 Crit Depth (ft) 0.0938 Crit Depth (ft) 0.0868 Crit Deptl-i (ft) 0.0776 Area (sf) 0.0228 Area (sf) 0.0238 Area I:.l 0.0249 Wetted Perim (ft) 0.4299 Wetted Perim (ft) 0.4719 Wetted Perim (ft) 0.5411 Top Width (ft) 0.3789 Top Width (ft) 0.4334 Top Width (ft) 0.5151 Figure 11: Manning's Calculations for 6-Inch, 8-Inch, and 12-Inch Pipes OPERATION AND MAINTAINANCE The proposed development will include an approximately 23,100 CIF detention vault located at the level one parking garage. The vault will be accessible via the entrance nearest 72d Avenue W. It is not anticipated that the detention vault will accumulate appreciable amounts of solids because the majority of collected runoff will be from clean roof surfaces. However, periodic maintenance is still required, including cleaning with a vactor truck. ProVac Clean Service has verbally confirmed that a typical vactor truck will need a height clearance of approximately 14 feet. Therefore, the truck will be able to access the vault through the vehicle and loading entry off 72d Avenue W to park in the loading area and run the hose down into the detention vault at the level one parking garage. See Figure 12 for the proposed vactor truck parking configuration. NAVIX Anthology of Edmonds Page 30 STORMWATER SITE PLAN Figure 12: Proposed Vactor Truck Configuration A complete on -site BMP operation and maintenance manual is included in Appendix B. NAVIX Anthology of Edmonds Page 31 STORMWATER SITE PLAN CSWPPP ANALYSIS AND DESIGN All erosion and sediment control measures shall be governed by the requirements of the City of Edmonds. A temporary erosion and sedimentation control plan will be prepared to assist the contractor in complying with these requirements. The Erosion and Sediment Control (ESC) plan will be included with the construction plans. Element 1: Preserve Vegetation/Mark Clearing Limits • Before beginning land disturbing activities, including clearing and grading, clearly mark all clearing limits, sensitive areas and their buffers, and trees that are to be preserved within the construction area. • Retain the duff layer, native top soil, and natural vegetation in an undisturbed state to the maximum degree practical. • Plastic, metal, or fabric fence may be used to mark the clearing limits. [Note: the difference between the practical use and proper installation of silt fencing and the proper use of clearing boundary fencing.] • If it is not practical to retain the duff layer in place, then stockpile it on -site, cover it to prevent erosion, and replace it immediately when you finish disturbing the site. Element 2: Establish Construction Access • Limit construction vehicle access and exit to one route, if possible. • Stabilize access points with a pad of quarry spalls, crushed rock, or other equivalent BMPs, to minimize tracking sediment onto roads. • Locate wheel wash or tire baths on site, if the stabilized construction entrance is not effective in preventing tracking sediment onto roads. • If sediment is tracked off site, clean the affected roadway thoroughly at the end of each day, or more frequently as necessary (for example, during wet weather). Remove sediment from roads by shoveling, sweeping, or pick up and transport the sediment to a controlled sediment disposal area. • Conduct street washing only after sediment is removed in accordance with the above bullet. • Control street wash wastewater by pumping back on site or otherwise preventing it from discharging into systems tributary to waters of the State. • Minimize construction site access points along linear projects, such as roadways. Street washing may require local jurisdiction approval. Element 3: Control Flow Rates • Protect properties and waterways downstream of development sites from erosion and the associated discharge of turbid waters due to increases in the velocity and peak volumetric flow rate of stormwater runoff from the project site, as required by local plan approval authority. • Where necessary to comply with the bullet above, construct stormwater retention or detention facilities as one of the first steps in grading. Assure that detention facilities function properly before constructing site improvements (e.g. impervious surfaces). • If permanent infiltration ponds are used for flow control during construction, protect these facilities from siltation during the construction phase. • Conduct downstream analysis if changes in off -site flows could impair or alter conveyance systems, streambanks, bed sediment, or aquatic habitat. NAVIX Anthology of Edmonds Page 32 STORMWATER SITE PLAN Even gently sloped areas need flow controls such as straw wattles or other energy dissipation / filtration structures. Place dissipation facilities closer together on steeper slopes. These methods prevent water from building higher velocities as it flows downstream within the construction site. Outlet structures designed for permanent detention ponds are not appropriate for use during construction without modification. If used during construction, install an outlet structure that will allow for long-term storage of runoff and enable sediment to settle. Verify that the pond is sized appropriately for this purpose. Restore ponds to their original design dimensions, remove sediment, and install a final outlet structure at completion of the project. • Erosion has the potential to occur because of increases in the volume, velocity, and peak flow rate of stormwater runoff from the project site. The local permitting agency may require pond designs that provide additional or different stormwater flow control. These requirements may be necessary to address local conditions or to protect properties and waterways downstream. • Sites that must implement flow control for the developed site condition must also control stormwater release rates during construction. Construction site stormwater discharges shall not exceed the discharge durations of the pre -developed condition for the range of pre - developed discharge rates from % of the 2-year flow through the 10-year flow as predicted by an approved continuous runoff model. The pre -developed condition to be matched shall be the land cover condition immediately prior to the development project. This restriction on release rates can affect the size of the storage pond and treatment cells Element 4: Install Sediment Controls • The Permittee must design, install and maintain effective erosion controls and sediment controls to minimize the discharge of pollutants. At a minimum, the Permittee must design, install and maintain such controls to: o Construct sediment control BMPs (sediment ponds, traps, filters, etc.) as one of the first steps in grading. These BMPs shall be functional before other land disturbing activities take place. o Minimize sediment discharges from the site. The design, installation and maintenance of erosion and sediment controls must address factors such as the amount, frequency, intensity and duration of precipitation, the nature of resulting stormwater runoff, and soil characteristics, including the range of soil particle sizes expected to be present on the site. o Direct stormwater runoff from disturbed areas through a sediment pond or other appropriate sediment removal BMP before the runoff leaves a construction site or before discharge to an infiltration facility. Runoff from fully stabilized areas may be discharged without a sediment removal BMP but must meet the flow control performance standard in Element #3, bullet #1. o Locate BMPs intended to trap sediment on site in a manner to avoid interference with the movement of juvenile salmonids attempting to enter off -channel areas or drainages. o Provide and maintain natural buffers around surface waters, direct stormwater to vegetated areas to increase sediment removal, and maximize stormwater infiltration, unless infeasible. NAVIX Anthology of Edmonds Page 33 STORMWATER SITE PLAN o Where feasible, design outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column. • Outlet structures that withdraw impounded stormwater from the surface to avoid discharging sediment that is still suspended lower in the water column are for the construction period only. If the pond using the construction outlet control is used for permanent stormwater controls, the appropriate outlet structure must be installed after the soil disturbance has ended. • Seed and mulch earthen structures such as dams, dikes, and diversions according to the timing indicated in Element #5. • Full stabilization includes concrete or asphalt paving; quarry spalls used as ditch lining; or the use of rolled erosion products, a bonded fiber matrix product, or vegetative cover in a manner that will fully prevent soil erosion. • The Local Permitting Authority may inspect and approve areas fully stabilized by means other than pavement or quarry spalls. • If installing a floating pump structure, include a stopper to prevent the pump basket from hitting the bottom of the pond. Element 5: Stabilize Soils • Stabilize exposed and unworked soils by application of effective BMPs that prevent erosion. Applicable BMPs include but are not limited to: temporary and permanent seeding, sodding, mulching, plastic covering, erosion control fabrics and matting, soil application of polyacrylamide (PAM), the early application of gravel base early on areas to be paved, and dust control. Control stormwater volume and velocity within the site to minimize soil erosion. • Control stormwater discharges, including both peak flow rates and total stormwater volume, to minimize erosion at outlets and to minimize downstream channel and stream bank erosion. • Soils must not remain exposed and unworked for more than the time periods set forth below to prevent erosion. o During the dry season (May 1- Sept. 30): 7 days. o During the wet season (October 1- April 30): 2 days. • Stabilize soils at the end of the shift before a holiday or weekend if needed based on the weather forecast. • Stabilize soil stockpiles from erosion, protect with sediment trapping measures, and where possible, be located away from storm drain inlets, waterways, and drainage channels. • Minimize the amount of soil exposed during construction activity. • Minimize the disturbance of steep slopes. • Minimize soil compaction and, unless infeasible, preserve topsoil. • Soils must not remain exposed and unworked for more than the time periods set forth above to prevent erosion for linear projects. • Soil stabilization measures should be appropriate for the time of year, site conditions, estimated duration of use, and potential water quality impacts that stabilization agents may have on downstream waters or ground water. NAVIX Anthology of Edmonds Page 34 STORMWATER SITE PLAN Ensure that gravel base used for stabilization is clean and does not contain fines or sediment. Element 6: Protect Slopes • Design and construct cut -and -fill slopes in a manner to minimize erosion. Applicable practices include, but are not limited to, reducing continuous length of slope with terracing and diversions, reducing slope steepness, and roughening slope surfaces (for example, track walking). • Divert off -site stormwater (run-on) or ground water away from slopes and disturbed areas with interceptor dikes, pipes, and/or swales. Off -site stormwater should be managed separately from stormwater generated on the site. • At the top of slopes, collect drainage in pipe slope drains or protected channels to prevent erosion. o Temporary pipe slope drains must handle the peak volumetric flow rate calculated using a 10-minute time step from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate predicted by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis must use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the Western Washington Hydrology Model (WWHM) to predict flows, bare soil areas should be modeled as "landscaped" area. • Place excavated material on the uphill side of trenches, consistent with safety and space considerations. • Place check dams at regular intervals within constructed channels that are cut down a slope. • Where 15-minute time steps are available in an approved continuous runoff model, they may be used directly without a correction factor. • Consider soil type and its potential for erosion. • Stabilize soils on slopes, as specified in Element #5. • BMP combinations are the most effective method of protecting slopes with disturbed soils. For example, use both mulching and straw erosion control blankets in combination. Element 7: Protect Permanent Drain Inlets • Protect all storm drain inlets made operable during construction so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. • Clean or remove and replace inlet protection devices when sediment has filled one-third of the available storage (unless a different standard is specified by the product manufacturer). • Where possible, protect all existing storm drain inlets so that stormwater runoff does not enter the conveyance system without first being filtered or treated to remove sediment. • Keep all approach roads clean. Do not allow sediment and street wash water to enter storm drains without prior and adequate treatment unless treatment is provided before the storm drain discharges to waters of the State. • Inlets should be inspected weekly at a minimum and daily during storm events. NAVIX Anthology of Edmonds Page 35 STORMWATER SITE PLAN Element 8: Stabilize Channels and Outlets • Design, construct, and stabilize all on -site conveyance channels to prevent erosion from the following expected peak flows: o Channels must handle the peak volumetric flow rate calculated using a 10- minute time step from a Type 1A, 10-year, 24-hour frequency storm for the developed condition. Alternatively, the 10-year, 1-hour flow rate indicated by an approved continuous runoff model, increased by a factor of 1.6, may be used. The hydrologic analysis must use the existing land cover condition for predicting flow rates from tributary areas outside the project limits. For tributary areas on the project site, the analysis must use the temporary or permanent project land cover condition, whichever will produce the highest flow rates. If using the Western Washington Hydrology Model (WWHM) to predict flows, bare soil areas should be modeled as "landscaped area." • Provide stabilization, including armoring material, adequate to prevent erosion of outlets, adjacent streambanks, slopes, and downstream reaches at the outlets of all conveyance systems. • The best method for stabilizing channels is to completely line the channel with a blanket product first, then add check dams as necessary to function as an anchor and to slow the flow of water. Element 9: Control Pollutants • Design, install, implement and maintain effective pollution prevention measures to minimize the discharge of pollutants. • Handle and dispose of all pollutants, including waste materials and demolition debris that occur on -site in a manner that does not cause contamination of stormwater. • Provide cover, containment, and protection from vandalism for all chemicals, liquid products, petroleum products, and other materials that have the potential to pose a threat to human health or the environment. On -site fueling tanks must include secondary containment. Secondary containment means placing tanks or containers within an impervious structure capable of containing 110% of the volume contained in the largest tank within the containment structure. Double -walled tanks do not require additional secondary containment. • Conduct maintenance, fueling, and repair of heavy equipment and vehicles using spill prevention and control measures. Clean contaminated surfaces immediately following any spill incident. • Discharge wheel wash or tire bath wastewater to a separate on -site treatment system that prevents discharge to surface water, such as closed -loop recirculation or upland land application, or to the sanitary sewer, with local sewer district approval. • Apply fertilizers and pesticides in a manner and at application rates that will not result in loss of chemical to stormwater runoff. Follow manufacturers' label requirements for application rates and procedures. • Use BMPs to prevent contamination of stormwater runoff by pH -modifying sources. The sources for this contamination include, but are not limited to: bulk cement, cement kiln dust, fly ash, new concrete washing and curing waters, waste streams generated from concrete grinding and sawing, exposed aggregate processes, dewatering concrete vaults, concrete pumping and mixer washout waters. NAVIX Anthology of Edmonds Page 36 STORMWATER SITE PLAN Adjust the pH of stormwater if necessary to prevent violations of the water quality standards. • Assure that washout of concrete trucks is performed off -site or in designated concrete washout areas only. Do not wash out concrete trucks onto the ground, or into storm drains, open ditches, streets, or streams. Do not dump excess concrete on site, except in designated concrete washout areas. Concrete spillage or concrete discharge to surface waters of the State is prohibited. • Obtain written approval from Ecology before using chemical treatment other than CO2 or dry ice to adjust pH. Element 10: Control De -Watering • Discharge foundation, vault, and trench dewatering water, which have characteristics similar to stormwater runoff at the site, into a controlled conveyance system before discharge to a sediment trap or sediment pond. • Discharge clean, non -turbid de -watering water, such as well -point ground water, to systems tributary to, or directly into surface waters of the State, as specified in Element #8, provided the de -watering flow does not cause erosion or flooding of receiving waters or interfere with the operation of the system. Do not route clean dewatering water through stormwater sediment ponds. Note that "surface waters of the State" may exist on a construction site as well as off site; for example, a creek running through a site. • Handle highly turbid or contaminated dewatering water separately from stormwater. Other treatment or disposal options may include: o Infiltration. o Transport off -site in a vehicle, such as a vacuum flush truck, for legal disposal in a manner that does not pollute state waters. o Ecology -approved on -site chemical treatment or other suitable treatment technologies. o Sanitary or combined sewer discharge with local sewer district approval if there is no other option. o Use of a sedimentation bag with outfall to a ditch or swale for small volumes of localized dewatering. Channels must be stabilized, as specified in Element #8. • Construction equipment operation, clamshell digging, concrete tremie pour, or work inside a cofferdam can create highly turbid or contaminated dewatering water. • Discharging sediment -laden (muddy) water into waters of the State likely constitutes violation of water quality standards for turbidity. The easiest way to avoid discharging muddy water is through infiltration and preserving vegetation. Element 11: Maintain BMPs • Maintain and repair all temporary and permanent erosion and sediment control BMPs as needed to assure continued performance of their intended function in accordance with BMP specifications. • Remove all temporary erosion and sediment control BMPs within 30 days after achieving final site stabilization or after the temporary BMPs are no longer needed. • Note: Some temporary erosion and sediment control BMPs are bio-degradable and designed to remain in place following construction such as compost socks. NAVIX Anthology of Edmonds Page 37 STORMWATER SITE PLAN • Provide protection to all BMPs installed for the permanent control of stormwater from sediment and compaction. All BMPs that are to remain in place following completion of construction shall be examined and placed in full operating conditions. If sediment enters the BMPs during construction, it shall be removed, and the facility shall be returned to the conditions specified in the construction documents. • Remove or stabilize trapped sediment on site. Permanently stabilize disturbed soil resulting from removal of BMPs or vegetation. Element 12: Manage the Project • Phase development projects to the maximum degree practicable and consider seasonal work limits. • Inspection and monitoring— Inspect, maintain, and repair all BMPs as needed to assure continued performance of their intended function. Conduct site inspections and monitoring in accordance with the Construction Stormwater General Permit or local plan approval authority. • Maintaining an updated construction SWPPP — Maintain, update, and implement the SWPPP in accordance with the Construction Stormwater General Permit. • Projects that disturb one or more acres must have, site inspections conducted by a Certified Erosion and Sediment Control Lead (CESCL). Project sites less than one acre (not part of a larger common plan of development or sale) may have a person without CESCL certification conduct inspections. By the initiation of construction, the SWPPP must identify the CESCL or inspector, who shall be present on -site or on -call at all times. • The CESCL or inspector (project sites less than one acre) must have the skills to assess the: o Site conditions and construction activities that could impact the quality of stormwater. o Effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. • The CESCL or inspector must examine stormwater visually for the presence of suspended sediment, turbidity, discoloration, and oil sheen. They must 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, construction site operators must correct the problems identified by: • Reviewing the SWPPP for compliance with the 13 construction SWPPP elements and making appropriate revisions within 7 days of the inspection. • Immediately beginning the process of fully implementing and maintaining appropriate source control and/or treatment BMPs as soon as possible, addressing the problems no later than within 10 days of the inspection. If installation of necessary treatment BMPs is not feasible within 10 days, the construction site operator may request an extension within the initial 10-day response period. • Documenting BMP implementation and maintenance in the site log book (applies only to sites that have coverage under the Construction Stormwater General Permit). • The CESCL or inspector must inspect all areas disturbed by construction activities, all BMPs, and all stormwater discharge points at least once every calendar week and within 24 hours of any discharge from the site. (For purposes of this condition, individual discharge events that last more than one day do not require daily inspections. For example, if a stormwater pond discharges continuously over the course of a week, only one inspection is required NAVIX Anthology of Edmonds Page 38 STORMWATER SITE PLAN that week.) The CESCL or inspector may reduce the inspection frequency for temporary stabilized, inactive sites to once every calendar month Phasing of Construction. o Phase development projects where feasible in order to prevent soil erosion and, to the maximum extent practical, and prevent transporting sediment from the site during construction. Revegetate exposed areas and maintain that vegetation as an integral part of the clearing activities for any phase. o Clearing and grading activities for developments shall be permitted only if conducted using an approved site development plan (e.g., subdivision approval) that establishes permitted areas of clearing, grading, cutting, and filling. Minimize removing trees and disturbing or compacting native soils when establishing permitted clearing and grading areas. Show on the site plans and the development site permitted clearing and grading areas and any other areas required to preserve critical or sensitive areas, buffers, native growth protection easements, or tree retention areas as may be required by local jurisdictions. • Seasonal Work Limitations o From October 1 through April 30, clearing, grading, and other soil disturbing activities is permitted only if shown to the satisfaction of the local permitting authority that the site operator will prevent silt -laden runoff from leaving the site through a combination of the following: ■ Site conditions including existing vegetative coverage, slope, soil type, and proximity to receiving waters. ■ Limit activities and the extent of disturbed areas. ■ Proposed erosion and sediment control measures. o Based on the information provided and/or local weather conditions, the local permitting authority may expand or restrict the seasonal limitation on site disturbance. The local permitting authority has the authority to take enforcement action —such as a notice of violation, administrative order, penalty, or stop -work order under the following circumstances: If, during the course of any construction activity or soil disturbance during the seasonal limitation period, sediment leaves the construction site causing a violation of the surface water quality standard; or If clearing and grading limits or erosion and sediment control measures shown in the approved plan are not maintained. The following activities are exempt from the seasonal clearing and grading limitations: o Routine maintenance and necessary repair of erosion and sediment control BMPs; o Routine maintenance of public facilities or existing utility structures that do not expose the soil or result in the removal of the vegetative cover to soil. o Activities where there is one hundred percent infiltration of surface water runoff within the site in approved and installed erosion and sediment control facilities. • Coordination with Utilities and Other Contractors o The primary project proponent shall evaluate, with input from utilities and other contractors, the stormwater management requirements for the entire project, including the utilities, when preparing the Construction SWPPP. • Inspection and Monitoring NAVIX Anthology of Edmonds Page 39 STORMWATER SITE PLAN o All BMPs must be inspected, maintained, and repaired as needed to assure continued performance of their intended function. Site inspections must be conducted by a person knowledgeable in the principles and practices of erosion and sediment control. The person must have the skills to 1) assess the site conditions and construction activities that could impact the quality of stormwater, and 2) assess the effectiveness of erosion and sediment control measures used to control the quality of stormwater discharges. o For construction sites one acre or larger that discharge stormwater to surface waters of the state, a CESCL must be identified in the construction SWPPP; this person must be on -site or on -call at all times. Certification must be obtained through an approved training program that meets the erosion and sediment control training standards established by Ecology. o Appropriate BMPs or design changes shall be implemented as soon as possible whenever inspection and/or monitoring reveals that the BMPs identified in the Construction SWPPP are inadequate, due to the actual discharge of /or potential to discharge a significant amount of any pollutant. Maintaining an Updated Construction SWPPP o Retain the Construction SWPPP on -site or within reasonable access to the site. o Modify the SWPPP whenever there is a change in the design, construction, operation, or maintenance at the construction site that has, or could have, a significant effect on the discharge of pollutants to waters of the state. The SWPPP must be modified if, during inspections or investigations conducted by the owner/operator, or the applicable local or state regulatory authority, it is determined that the SWPPP is ineffective in eliminating or significantly minimizing pollutants in stormwater discharges from the site. Modify the SWPPP as necessary to include additional or modified BMPs designed to correct problems identified. Complete revisions to the SWPPP within seven (7) days following the inspection. Element 13: Protect Low Impact Development BMPs Protect all Bioretention and Rain Garden BMPs from sedimentation through installation and maintenance of erosion and sediment control BMPs on portions of the site that drain into the Bioretention and/or Rain Garden BMPs. Restore the BMPs to their fully functioning condition if they accumulate sediment during construction. Restoring the BMP must include removal of sediment and any sediment -laden Bioretention/rain garden soils, and replacing the removed soils with soils meeting the design specification. • Prevent compacting Bioretention and rain garden BMPs by excluding construction equipment and foot traffic. Protect completed lawn and landscaped areas from compaction due to construction equipment. • Control erosion and avoid introducing sediment from surrounding land uses onto permeable pavements. Do not allow muddy construction equipment on the base material or pavement. Do not allow sediment -laden runoff onto permeable pavements. • Pavements fouled with sediments or no longer passing an initial infiltration test must be cleaned using procedures from the local stormwater manual or the manufacturer's procedures. • Keep all heavy equipment off existing soils under LID facilities that have been excavated to final grade to retain the infiltration rate of the soils. NAVIX Anthology of Edmonds Page 40 STORMWATER SITE PLAN See Chapter 5: Precision Site Preparation, Construction & Inspection of LID Facilities in the LID Technical Guidance Manual for Puget Sound (2012) for more detail on protecting LID integrated management practices. Note that the LID Technical Guidance Manual for Puget Sound (2012) is for additional informational purposes only. You must follow the guidance within this manual if there are any discrepancies between this manual and the LID Technical Guidance Manual for Puget Sound (2012). NAVIX Anthology of Edmonds Page 41 STORMWATER SITE PLAN SPECIAL REPORTS AND STUDIES Special reports and studies prepared for this project include: • Geotechnical Engineering Report, prepared by Terracon Consultants, Inc., dated December 20, 2018 and addendum dated September 18, 2019. • Operation and Maintenance Manual • CSWPP Narrative and Plans PERMITS The following permits are anticipated to be needed for the project: • City of Edmonds Design Review and SEPA Environmental Review • City of Edmonds Building Permit Review with Mechanical, Electrical, Plumbing, and Fire Code Review NAVIX Anthology of Edmonds Page 42 STORMWATER SITE PLAN APPENDIX A WWHM DATA AND OUTPUT NAVIX Anthology of Edmonds Page 43 WWHM2012 PROJECT REPORT General Model Information Project Name: CASL Edmonds-Vault_210628 Site Name: Edmonds Senior Living Site Address: 21200 72nd Ave W City: Edmonds, WA Report Date: 6/28/2021 MGS Region: Puget East Data Start: 1901/10/1 Data End: 2058/09/30 Timestep: Hourly DOT Data Number03 Version Date: 2019/09/13 Version: 4.2.17 POC Thresholds Low Flow Threshold for POC1: 50 Percent of the 2 Year High Flow Threshold for POC1: 50 Year CASL Edmonds -Vault 210628 6/28/2021 4:24:13 PM Page 2 Landuse Basin Data Predeveloped Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Forest, Flat 0.847 Pervious Total 0.847 Impervious Land Use acre Impervious Total 0 Basin Total 0.847 Element Flows To: Surface Interflow Groundwater CASL Edmonds-Vault_210628 6/28/2021 4:24:13 PM Page 3 Mitigated Land Use Basin 1 Bypass: No GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.131 Pervious Total 0.131 Impervious Land Use acre ROOF TOPS FLAT 0.603 SIDEWALKS FLAT 0.087 Impervious Total 0.69 Basin Total 0.821 Element Flows To: Surface Interflow Vault 1 Vault 1 Groundwater CASL Edmonds -Vault 210628 6/28/2021 4:24:13 PM Page 4 Basin 2 Bypass: Yes GroundWater: No Pervious Land Use acre C, Lawn, Flat 0.004 Pervious Total 0.004 Impervious Land Use acre SIDEWALKS FLAT 0.022 Impervious Total 0.022 Basin Total 0.026 Element Flows To: Surface Interflow Groundwater CASL Edmonds -Vault 210628 6/28/2021 4:24:13 PM Page 5 Mitigated Routing Vault 1 Width: Length: Depth: Discharge Structure Riser Height: Riser Diameter: Notch Type: Notch Width: Notch Height: Orifice 1 Diameter: Element Flows To: Outlet 1 40 ft. 55 ft. 10 ft. 9.5 ft. 18 in. Rectangular 0.003 ft. 3.000 ft. 0.3125 inElevation:0 ft. Outlet 2 Vault Hydraulic Table Stage(feet) Area(ac.) Volume(ac-ft.) Discharge(cfs) Infilt(cfs) 0.0000 0.050 0.000 0.000 0.000 0.1111 0.050 0.005 0.000 0.000 0.2222 0.050 0.011 0.001 0.000 0.3333 0.050 0.016 0.001 0.000 0.4444 0.050 0.022 0.001 0.000 0.5556 0.050 0.028 0.002 0.000 0.6667 0.050 0.033 0.002 0.000 0.7778 0.050 0.039 0.002 0.000 0.8889 0.050 0.044 0.002 0.000 1.0000 0.050 0.050 0.002 0.000 1.1111 0.050 0.056 0.002 0.000 1.2222 0.050 0.061 0.002 0.000 1.3333 0.050 0.067 0.003 0.000 1.4444 0.050 0.073 0.003 0.000 1.5556 0.050 0.078 0.003 0.000 1.6667 0.050 0.084 0.003 0.000 1.7778 0.050 0.089 0.003 0.000 1.8889 0.050 0.095 0.003 0.000 2.0000 0.050 0.101 0.003 0.000 2.1111 0.050 0.106 0.003 0.000 2.2222 0.050 0.112 0.004 0.000 2.3333 0.050 0.117 0.004 0.000 2.4444 0.050 0.123 0.004 0.000 2.5556 0.050 0.129 0.004 0.000 2.6667 0.050 0.134 0.004 0.000 2.7778 0.050 0.140 0.004 0.000 2.8889 0.050 0.145 0.004 0.000 3.0000 0.050 0.151 0.004 0.000 3.1111 0.050 0.157 0.004 0.000 3.2222 0.050 0.162 0.004 0.000 3.3333 0.050 0.168 0.004 0.000 3.4444 0.050 0.174 0.004 0.000 3.5556 0.050 0.179 0.005 0.000 3.6667 0.050 0.185 0.005 0.000 3.7778 0.050 0.190 0.005 0.000 3.8889 0.050 0.196 0.005 0.000 4.0000 0.050 0.202 0.005 0.000 CASL Edmonds-Vault_210628 6/28/2021 4:24:13 PM Page 7 4.1111 0.050 0.207 0.005 0.000 4.2222 0.050 0.213 0.005 0.000 4.3333 0.050 0.218 0.005 0.000 4.4444 0.050 0.224 0.005 0.000 4.5556 0.050 0.230 0.005 0.000 4.6667 0.050 0.235 0.005 0.000 4.7778 0.050 0.241 0.005 0.000 4.8889 0.050 0.246 0.005 0.000 5.0000 0.050 0.252 0.005 0.000 5.1111 0.050 0.258 0.006 0.000 5.2222 0.050 0.263 0.006 0.000 5.3333 0.050 0.269 0.006 0.000 5.4444 0.050 0.275 0.006 0.000 5.5556 0.050 0.280 0.006 0.000 5.6667 0.050 0.286 0.006 0.000 5.7778 0.050 0.291 0.006 0.000 5.8889 0.050 0.297 0.006 0.000 6.0000 0.050 0.303 0.006 0.000 6.1111 0.050 0.308 0.006 0.000 6.2222 0.050 0.314 0.006 0.000 6.3333 0.050 0.319 0.006 0.000 6.4444 0.050 0.325 0.006 0.000 6.5556 0.050 0.331 0.006 0.000 6.6667 0.050 0.336 0.007 0.000 6.7778 0.050 0.342 0.008 0.000 6.8889 0.050 0.347 0.009 0.000 7.0000 0.050 0.353 0.010 0.000 7.1111 0.050 0.359 0.011 0.000 7.2222 0.050 0.364 0.012 0.000 7.3333 0.050 0.370 0.013 0.000 7.4444 0.050 0.376 0.014 0.000 7.5556 0.050 0.381 0.016 0.000 7.6667 0.050 0.387 0.017 0.000 7.7778 0.050 0.392 0.018 0.000 7.8889 0.050 0.398 0.020 0.000 8.0000 0.050 0.404 0.026 0.000 8.1111 0.050 0.409 0.029 0.000 8.2222 0.050 0.415 0.031 0.000 8.3333 0.050 0.420 0.033 0.000 8.4444 0.050 0.426 0.036 0.000 8.5556 0.050 0.432 0.038 0.000 8.6667 0.050 0.437 0.041 0.000 8.7778 0.050 0.443 0.044 0.000 8.8889 0.050 0.448 0.046 0.000 9.0000 0.050 0.454 0.049 0.000 9.1111 0.050 0.460 0.052 0.000 9.2222 0.050 0.465 0.055 0.000 9.3333 0.050 0.471 0.058 0.000 9.4444 0.050 0.477 0.061 0.000 9.5556 0.050 0.482 0.271 0.000 CASL Edmonds-Vault_210628 6/28/2021 4:24:13 PM Page 8 Analysis Results POC 1 0.04 0.03 )U 0.02 0 J lL 0.01 0.01 1 °A � - Cumulative Probability - - % � °�1 0,01 ++ 0001 - - 0001 10 1An Percerttt Time Exceedir�9 OS 1 2 5 10 20 30 50 10 80 90 95 9° 99 99.5 1 + Predeveloped x Mitigated Predeveloped Landuse Totals for POC #1 Total Pervious Area: 0.847 Total Impervious Area: 0 Mitigated Landuse Totals for POC #1 Total Pervious Area: 0.135 Total Impervious Area: 0.712 Flow Frequency Method: Log Pearson Type III 17B Flow Frequency Return Periods for Predeveloped. POC #1 Return Period Flow(cfs) 2 year 0.014101 5 year 0.023171 10 year 0.028283 25 year 0.033593 50 year 0.036795 100 year 0.03945 Flow Frequency Return Periods for Mitigated. POC #1 Return Period Flow(cfs) 2 year 0.010097 5 year 0.01439 10 year 0.018004 25 year 0.023584 50 year 0.028575 100 year 0.034372 Annual Peaks Annual Peaks for Predeveloped and Mitigated. POC #1 Year Predeveloped Mitigated 1902 0.020 0.009 1903 0.007 0.010 1904 0.015 0.012 1905 0.008 0.010 1906 0.003 0.007 1907 0.022 0.010 1908 0.014 0.009 1909 0.015 0.009 1910 0.025 0.011 1911 0.013 0.009 CASL Edmonds -Vault 210628 6/28/2021 4:24:14 PM Page 9 1912 0.051 0.016 1913 0.021 0.010 1914 0.005 0.017 1915 0.007 0.009 1916 0.012 0.010 1917 0.005 0.007 1918 0.014 0.014 1919 0.010 0.008 1920 0.013 0.009 1921 0.013 0.010 1922 0.015 0.010 1923 0.012 0.010 1924 0.007 0.008 1925 0.006 0.007 1926 0.012 0.009 1927 0.015 0.008 1928 0.010 0.010 1929 0.024 0.012 1930 0.013 0.012 1931 0.013 0.009 1932 0.009 0.008 1933 0.011 0.010 1934 0.032 0.039 1935 0.011 0.009 1936 0.018 0.010 1937 0.015 0.011 1938 0.015 0.009 1939 0.001 0.009 1940 0.012 0.011 1941 0.012 0.009 1942 0.018 0.020 1943 0.006 0.011 1944 0.017 0.015 1945 0.013 0.010 1946 0.012 0.009 1947 0.009 0.007 1948 0.029 0.010 1949 0.024 0.012 1950 0.013 0.008 1951 0.015 0.009 1952 0.047 0.016 1953 0.037 0.020 1954 0.011 0.009 1955 0.009 0.008 1956 0.006 0.007 1957 0.016 0.009 1958 0.040 0.041 1959 0.023 0.034 1960 0.008 0.008 1961 0.024 0.019 1962 0.012 0.010 1963 0.006 0.006 1964 0.009 0.013 1965 0.029 0.031 1966 0.005 0.007 1967 0.011 0.008 1968 0.015 0.009 1969 0.010 0.010 CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 10 1970 0.016 0.010 1971 0.030 0.012 1972 0.019 0.020 1973 0.022 0.013 1974 0.014 0.012 1975 0.033 0.023 1976 0.014 0.012 1977 0.008 0.008 1978 0.027 0.029 1979 0.007 0.009 1980 0.014 0.010 1981 0.014 0.010 1982 0.009 0.008 1983 0.023 0.012 1984 0.006 0.010 1985 0.013 0.009 1986 0.011 0.009 1987 0.023 0.012 1988 0.017 0.009 1989 0.013 0.007 1990 0.017 0.008 1991 0.013 0.010 1992 0.020 0.017 1993 0.016 0.010 1994 0.029 0.010 1995 0.007 0.008 1996 0.033 0.033 1997 0.015 0.009 1998 0.014 0.010 1999 0.000 0.008 2000 0.010 0.011 2001 0.007 0.008 2002 0.023 0.014 2003 0.015 0.010 2004 0.016 0.010 2005 0.021 0.013 2006 0.010 0.009 2007 0.011 0.010 2008 0.014 0.009 2009 0.009 0.009 2010 0.007 0.010 2011 0.009 0.008 2012 0.012 0.010 2013 0.011 0.007 2014 0.007 0.007 2015 0.026 0.012 2016 0.004 0.007 2017 0.024 0.013 2018 0.044 0.037 2019 0.045 0.035 2020 0.014 0.011 2021 0.019 0.012 2022 0.006 0.010 2023 0.015 0.011 2024 0.056 0.016 2025 0.012 0.008 2026 0.022 0.011 2027 0.009 0.010 CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 11 2028 0.005 0.006 2029 0.016 0.011 2030 0.032 0.012 2031 0.008 0.007 2032 0.006 0.007 2033 0.007 0.006 2034 0.008 0.007 2035 0.035 0.022 2036 0.018 0.010 2037 0.003 0.009 2038 0.019 0.010 2039 0.001 0.011 2040 0.006 0.008 2041 0.010 0.008 2042 0.036 0.018 2043 0.015 0.011 2044 0.022 0.011 2045 0.013 0.009 2046 0.016 0.028 2047 0.010 0.009 2048 0.014 0.008 2049 0.013 0.010 2050 0.008 0.009 2051 0.014 0.013 2052 0.008 0.009 2053 0.014 0.026 2054 0.022 0.011 2055 0.005 0.009 2056 0.005 0.009 2057 0.009 0.008 2058 0.011 0.009 Ranked Annual Peaks Ranked Annual Peaks for Predeveloped and Mitigated. POC #1 Rank Predeveloped Mitigated 1 0.0558 0.0409 2 0.0505 0.0387 3 0.0468 0.0368 4 0.0451 0.0347 5 0.0437 0.0343 6 0.0397 0.0332 7 0.0370 0.0314 8 0.0363 0.0292 9 0.0347 0.0279 10 0.0330 0.0260 11 0.0326 0.0226 12 0.0321 0.0217 13 0.0315 0.0204 14 0.0305 0.0202 15 0.0292 0.0199 16 0.0288 0.0194 17 0.0287 0.0181 18 0.0274 0.0172 19 0.0256 0.0167 20 0.0246 0.0161 21 0.0240 0.0160 22 0.0239 0.0158 23 0.0239 0.0153 CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 12 24 0.0239 0.0143 25 0.0234 0.0136 26 0.0233 0.0132 27 0.0229 0.0131 28 0.0229 0.0129 29 0.0223 0.0128 30 0.0221 0.0127 31 0.0218 0.0123 32 0.0218 0.0123 33 0.0216 0.0121 34 0.0212 0.0121 35 0.0211 0.0120 36 0.0198 0.0119 37 0.0196 0.0119 38 0.0194 0.0118 39 0.0193 0.0117 40 0.0189 0.0116 41 0.0185 0.0116 42 0.0184 0.0115 43 0.0178 0.0115 44 0.0171 0.0115 45 0.0169 0.0114 46 0.0168 0.0114 47 0.0164 0.0113 48 0.0163 0.0112 49 0.0163 0.0111 50 0.0162 0.0110 51 0.0158 0.0110 52 0.0156 0.0109 53 0.0154 0.0108 54 0.0154 0.0107 55 0.0154 0.0106 56 0.0153 0.0104 57 0.0152 0.0103 58 0.0151 0.0103 59 0.0151 0.0102 60 0.0151 0.0102 61 0.0150 0.0102 62 0.0148 0.0102 63 0.0147 0.0101 64 0.0145 0.0101 65 0.0145 0.0101 66 0.0144 0.0101 67 0.0141 0.0100 68 0.0140 0.0100 69 0.0140 0.0100 70 0.0139 0.0100 71 0.0139 0.0099 72 0.0138 0.0099 73 0.0137 0.0099 74 0.0137 0.0098 75 0.0136 0.0098 76 0.0135 0.0097 77 0.0134 0.0097 78 0.0134 0.0097 79 0.0133 0.0097 80 0.0132 0.0097 81 0.0132 0.0097 CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 13 82 0.0131 0.0096 83 0.0131 0.0096 84 0.0130 0.0096 85 0.0130 0.0096 86 0.0129 0.0096 87 0.0126 0.0095 88 0.0126 0.0095 89 0.0122 0.0095 90 0.0122 0.0094 91 0.0121 0.0094 92 0.0121 0.0094 93 0.0121 0.0093 94 0.0119 0.0092 95 0.0117 0.0092 96 0.0116 0.0092 97 0.0115 0.0092 98 0.0112 0.0092 99 0.0110 0.0092 100 0.0110 0.0091 101 0.0109 0.0091 102 0.0108 0.0091 103 0.0108 0.0091 104 0.0107 0.0090 105 0.0107 0.0090 106 0.0103 0.0090 107 0.0102 0.0090 108 0.0102 0.0089 109 0.0101 0.0089 110 0.0099 0.0089 111 0.0096 0.0088 112 0.0096 0.0088 113 0.0093 0.0088 114 0.0093 0.0088 115 0.0093 0.0088 116 0.0092 0.0088 117 0.0090 0.0088 118 0.0089 0.0086 119 0.0088 0.0086 120 0.0088 0.0086 121 0.0086 0.0086 122 0.0085 0.0085 123 0.0084 0.0085 124 0.0083 0.0084 125 0.0082 0.0084 126 0.0082 0.0084 127 0.0080 0.0084 128 0.0076 0.0083 129 0.0073 0.0082 130 0.0073 0.0081 131 0.0072 0.0081 132 0.0070 0.0081 133 0.0069 0.0081 134 0.0069 0.0079 135 0.0068 0.0079 136 0.0068 0.0079 137 0.0065 0.0078 138 0.0064 0.0076 139 0.0064 0.0076 CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 14 140 0.0063 0.0076 141 0.0063 0.0075 142 0.0061 0.0075 143 0.0059 0.0075 144 0.0059 0.0074 145 0.0055 0.0074 146 0.0055 0.0073 147 0.0054 0.0073 148 0.0054 0.0073 149 0.0051 0.0073 150 0.0049 0.0073 151 0.0045 0.0071 152 0.0039 0.0071 153 0.0030 0.0070 154 0.0029 0.0067 155 0.0012 0.0064 156 0.0007 0.0063 157 0.0002 0.0059 CASL Edmonds -Vault 210628 6/28/2021 4:24:26 PM Page 15 Duration Flows The Facility PASSED Flow(cfs) Predev Mit Percentage Pass/Fail 0.0071 13434 10727 79 Pass 0.0074 12236 8387 68 Pass 0.0077 11172 6844 61 Pass 0.0080 10213 5782 56 Pass 0.0083 9359 5056 54 Pass 0.0086 8617 4489 52 Pass 0.0089 7935 4048 51 Pass 0.0092 7337 3673 50 Pass 0.0095 6786 3386 49 Pass 0.0098 6274 3145 50 Pass 0.0101 5804 2930 50 Pass 0.0104 5348 2737 51 Pass 0.0107 4938 2572 52 Pass 0.0110 4564 2407 52 Pass 0.0113 4220 2238 53 Pass 0.0116 3906 2102 53 Pass 0.0119 3628 1967 54 Pass 0.0122 3355 1857 55 Pass 0.0125 3120 1766 56 Pass 0.0128 2907 1679 57 Pass 0.0131 2702 1585 58 Pass 0.0134 2541 1481 58 Pass 0.0137 2374 1383 58 Pass 0.0140 2224 1299 58 Pass 0.0143 2084 1217 58 Pass 0.0146 1956 1140 58 Pass 0.0149 1846 1071 58 Pass 0.0152 1740 1015 58 Pass 0.0155 1634 952 58 Pass 0.0158 1551 882 56 Pass 0.0161 1467 821 55 Pass 0.0164 1390 766 55 Pass 0.0167 1324 712 53 Pass 0.0170 1244 661 53 Pass 0.0173 1185 611 51 Pass 0.0176 1119 570 50 Pass 0.0179 1054 539 51 Pass 0.0182 1013 505 49 Pass 0.0185 950 472 49 Pass 0.0188 922 446 48 Pass 0.0191 878 420 47 Pass 0.0194 842 393 46 Pass 0.0197 814 368 45 Pass 0.0200 787 347 44 Pass 0.0203 761 322 42 Pass 0.0206 737 303 41 Pass 0.0209 710 285 40 Pass 0.0212 680 270 39 Pass 0.0215 653 260 39 Pass CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 16 0.0230 509 221 43 Pass 0.0233 488 215 44 Pass 0.0236 470 209 44 Pass 0.0239 446 204 45 Pass 0.0242 435 201 46 Pass 0.0245 417 198 47 Pass 0.0248 400 193 48 Pass 0.0251 380 188 49 Pass 0.0254 364 184 50 Pass 0.0257 348 182 52 Pass 0.0260 333 174 52 Pass 0.0263 316 167 52 Pass 0.0266 303 166 54 Pass 0.0269 283 163 57 Pass 0.0272 275 160 58 Pass 0.0275 258 153 59 Pass 0.0278 248 147 59 Pass 0.0281 236 134 56 Pass 0.0284 226 125 55 Pass 0.0287 212 118 55 Pass 0.0290 201 108 53 Pass 0.0293 187 104 55 Pass 0.0296 178 101 56 Pass 0.0299 170 97 57 Pass 0.0302 158 95 60 Pass 0.0305 146 91 62 Pass 0.0308 131 88 67 Pass 0.0311 121 80 66 Pass 0.0314 114 73 64 Pass 0.0317 102 68 66 Pass 0.0320 92 65 70 Pass 0.0323 87 60 68 Pass 0.0326 81 56 69 Pass 0.0329 73 53 72 Pass 0.0332 72 47 65 Pass 0.0335 65 42 64 Pass 0.0338 59 39 66 Pass 0.0341 58 35 60 Pass 0.0344 52 31 59 Pass 0.0347 44 30 68 Pass 0.0350 41 26 63 Pass 0.0353 37 26 70 Pass 0.0356 33 25 75 Pass 0.0359 31 23 74 Pass 0.0362 29 18 62 Pass 0.0365 27 15 55 Pass 0.0368 24 13 54 Pass CASL Edmonds-Vault_210628 6/28/2021 4:24:26 PM Page 17 Disclaimer Legal Notice This program and accompanying documentation are provided 'as -is' without warranty of any kind. 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Clear Creek Solutions, Inc. 6200 Capitol Blvd. Ste F Olympia, WA. 98501 Toll Free 1(866)943-0304 Local (360)943-0304 www.clearcreeksolutions.com CASL Edmonds -Vault 210628 6/28/2021 4:24:37 PM Page 27 STORMWATER SITE PLAN APPENDIX B OPERATIONS AND MAINTENANCE MANUAL NAVIX Anthology of Edmonds Page 44 STORMWATER SITE PLAN No. 3 - Closed Detention Systems (Tanks/Vaults) Maintenance Defect Conditions When Maintenance is Needed Results Expected Component When Maintenance is Performed Storage Area Plugged Air Vents One-half of the cross section of a vent is Vents open and blocked at any point or the vent is damaged. functioning. Debris and Sediment Accumulated sediment depth exceeds 10% All sediment and of the diameter of the storage area for 1/2 debris removed from length of storage vault or any point depth storage area. exceeds 15% of diameter_ (Example: 72-inch storage tank would require cleaning when sediment reaches depth of 7 inches for more than 1/2 length of tank.) Joints Between Any openings or voids allowing material to All joint between Tank,Pipe Section be transported into facility. tanktpipe sections (Will require engineering analysis to are sealed. determine structural stability). Tank Pipe Bent Out Any part of tank/pipe is bent out of shape Tank; pipe repaired or of Shape more than 10% of its design shape. (Review replaced to design. required by engineer to determine structural stability). Vault Structure Cracks wider than 112-inch and any Vault replaced or Includes Cracks in evidence of soil particles entering the repaired to design Wall, Bottom, structure through the cracks. or specifications and is Damage to Frame maintenancelinspection personnel structurally sound. and/or Top Slab determines that the vault is not structurally sound. Cracks wider than 1/2-inch at the joint of any No cracks ma trap inlet/outlet pipe or any evidence of soil 1/4-inch wide at the particles entering the vault through the walls_ joint of the inlet/outlet pipe. Manhole Cover Not in Place Cover is missing or only partially in place. Manhole is closed. Any open manhole requires maintenance_ _ocking Mechanism Mechanism cannot be opened by one Mechanism opens Not Working maintenance person with proper tools. Botts with proper tools. into frame have less than 1/2 inch of thread (may not apply to setf-locking lids). Cover Difficult to One maintenance person cannot remove lid Cover can be Remove after applying normal lifting pressure. Intent removed and is to keep cover from sealing off access to reinstalled by one maintenance. maintenance person. Ladder Rungs Unsafe Ladder is unsafe due to missing rungs, Ladder meets design misalignment, not securey attached to standards. Alkrws structure wall, rust, or cracks. maintenance person safe access. Catch Basins See "Catch Basins' See "Catch Basins' (No. 5). See "Catch Basins - (No. 5) (No. 5). NAVIX Anthology of Edmonds Page 45 STORMWATER SITE PLAN No. 4 — Control Structure/Flow Restrictor Maintenance Defect Condition When Maintenance is Needed Results Expected Component When Maintenance Is Performed Trash and Debris Material exceeds 25% of sump depth or 1 Control structure Includes Sediment) foot below orifice plate. orifice is not blocked All trash and debris removed. Structural Damage Structure is not securely attached to Structure securety manhole wall. attached to wall and outlet pope. Structure is not in upright position (allow up Structure in correct to 10% from plumb). position. Connections to outlet pipe are not watertight Connections to outlet and show signs of rust. pipe are water tight: structure repaired or replaced and works as designed. Any holes -other than designed holes -in the Structure has no structure. holes other than designed holes. Cleanout Gate Damaged or Missing Cleanout gate is not watertight or is missing. Gate is watertight and works as designed. Gate cannot be moved up and down by one Gate moves up and maintenance person. down easily and is watertight- Chain/rod leading to gate is missing or Chain is in place and damaged_ works as designed. Gate is rusted over 50% of its surface area. Gate is repaired or replaced to meet design standards. Orifice Plat =1ariaged or Missing Control device is not working properly due to missing, out of place, or bent orifice plate. Plate is in place and works as designed. Obstructions Any trash, debris, sediment. or vegetation Plate is free of all blocking the plate. obstructions and works as designed. Overflow Pipe Obstructions Any trash or debris blocking (or having the Pipe is free of all potential of bloclung) the overflow pipe. obstructions and works as designed. Manhole See "Closed See "Closed Detention Systems" (No. 3). See "Closed Detention Systems" Detention Systems - (No. 3). (No. 3). Catch basin See "Catch Basins' See "Catch Basins' (No. 5). See "Catch Basins - (No. 5). (No. 5)- NAVIX Anthology of Edmonds Page 46 STORMWATER SITE PLAN No. 5 — Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When component Maintenance is performed Trash & Trash or debris which is located immediately No Trash or debris locate Debris in front of the catch basin opening or is immediately in front of blocking inletting capacity of the basin by catch basin or on grate more than 10%. opening. Trash or debris (in the basin) that exceeds 60 No trash or debris in the percent of the sump depth as measured from catch basin. the bottom of basin to invert of the lowest pipe into or out of the basin, but in no case less than a minimum of six inches clearance from the debris surface to the invert of the lowest pipe. Trash or debris in any inlet or outlet pipe Inlet and outlet pipes free blocking more than 1;3 of its height. of trash or debris. Dead animals or vegetation that could No dead animals or generate odors that could cause complaints vegetation present vnthin or dangerous gases (e.g., methane). the catch basin. pediment Sediment (in the basin) that exceeds 60 No sediment in the catc`i percent of the sump depth as measured from basin the bottom of basin to invert of the lowest pipe into or out of the basin, but in no cap _ less than a minimum of 6 inches clearance from the sediment surface to the invert of the lowest pipe. Structure Top slab has holes larger than 2 square Top slab is free of hole__ Damage to inches or cracks wider than 1 A inch and cracks. Frame andior Top Slab (Intent is to make sure no material is running into basin) - Frame not sitting flush on top slab, i.e., Frame is sitting flush on separation of more than 14 inch of the frame the nser rings or top slab from the top slab. Frame not securely and firmly attached. attached Fractures or Maintenance person judges that structure is Basin replaced or repaired Cracks in insound. to design standards. Basin Wallsi Bottom Srout fillet has separated or cracked wider Pipe is regrouted and :nan V2 inch and longer than 1 foot at the secure at basin wall. Dint of any inlevoutlet pipe or any evidence of soil particles entering catch basin through cracks. Settlement! If failure of basin has created a safety, Basin replaced or repaired Misalignment function. or design problem. to design standards. Vegetation Vegetation growing across and blocking more No vegetation blocking than 10% of the basin opening. opening to basin. Vegetation growing in inleb'outlet pipe joints No vegetation or root that is more than six inches tall and less than growth present. six inches apart. Contamination See "Detention Ponds" (No. 1). No pollution present. and Pollution NAVIX Anthology of Edmonds Page 47 STORMWATER SITE PLAN No. 5 - Catch Basins Maintenance Defect Conditions When Maintenance is Needed Results Expected When Component Maintenance is performed Catch Basin Cover Not in Cover is missing or only partially in place. Catch basin cover is Cover Place Any open catch basin requires maintenance. closed Locking Mechanism cannot be opened by one Mechanism opens with Mechanism maintenance person with proper tools. Bolts proper tools. Not Working into frame have less than 112 inch of thread. Cover Difficult One maintenance person cannot remove lid Cover can be removed by to Remove after applying normal lifting pressure. one maintenance person (Intent is keep cover from sealing off access to maintenance.) Ladder Ladder Rungs Ladder is unsafe due to missing rungs. not Ladder meets design Unsafe securely attached to basin wall, standards and allows misalignment, rust. cracks. or sharp edges. maintenance person safe access. Metal Grates Grate opening Grate with opening wider than T8 inch. Grate opening meets (If Applicable) Unsafe design standards. Trash and Trash and debris that is blocking more than Grate free of trash and Debris 20% of grate surface inletting capacity. debris. Damaged or Grate missing or broken member(s) of the Grate is in place and Missing. grate. meets design standards. NAVIX Anthology of Edmonds Page 48 STORMWATER SITE PLAN No. 18 — Catchbasin Inserts Maintenance Defect Conditions When Maintenance Is Results Expected When Component Needed Maintenance is Performed General Sediment When sediment forms a cap over the No sediment cap on the insert Accumulation insert media of the insert andlor unit_ media and its unit_ Trash and Trash and debris accumulates on insert Trash and debris removed Debris unit creating a blockagelrestriction. from insert unit. Runoff freely Accumulation flows into catch basin. Media Insert Not Effluent water from media insert has a Effluent water from media Removing Oil visible sheen. insert is free of oils and has no visible sheen. Media Insert Catch basin insert is saturated with water Remove and replace media Water Saturated and no longer has the capacity to insert absorb. Media Insert -Oil Media oil saturated due to petroleum spill Remove and replace media Saturated that drains into catch basin. insert. Media Insert Use Media has been used beyond the typical Remove and replace meow at Beyond Normal average life of media insert product. regular intervals, depending on Product Life insert product. NAVIX Anthology of Edmonds Page 49 STORMWATER SITE PLAN 0 MTEC 1. OPERATION & MAINTENANCE This section is structured as follows: 1.01 RECOMMENDED MAINTENANCE & SPARE PARTS 1.02 OPERATION 1.03 PERMITS & REPORTS 1.04 WARRANTY NAVIX Anthology of Edmonds Page 50 STORMWATER SITE PLAN R MTEC 1.01 RECOMMENDED MAINTENANCE & SPARE PARTS 1. Safety precautions A. Always disconnect the power and perform proper lockout/tag out procedures before servicing the unit. B. Be aware of the risk of electrical accidents. C. Do not ignore health hazards. Observe strict cleanliness. D. Disconnecting power and/or performing electrical testing should be performed by a qualified person. E. The pump must NOT be lifted out by the guide cable. Use the appropriate lifting eye and chain attached to the pump handle. The cable is only used for a guide to get the lifting eye to the chain. 2. Daily inspections A. Check current — to be within the rated current. If ammeter fluctuation is great, even though within the limits of the pump rating, foreign matter may be clogging the pump, If the quantity of liquid discharged falls suddenly, foreign matter may be blocking the suction inlet. Document the current readings so there is a basis to compare to. B. Check voltage — power supply voltage variation = within +- 10% of the rated voltage. Document the voltage readings so there is a basis to compare to. C. Check for abnormal noise or vibration D. Check and record pump runtime values if available. E. Unusual readings or observations may indicate a problem requiring immediate service. 3. Regular inspections A. Monthly (1) Measure the insulation resistance. Insulation resistance value should be more than 1 mega ohm (MQ). If resistance starts to fall rapidly even with an initial indication of over 1 mega ohm, this may be an indication of trouble and repair work is required. Document what the reading is so it can be compared to the last reading. (2) Make sure that the lifting equipment is in good condition and show no signs of abnormal wear or corrosion, (3) Replace any worn or defective lifting equipment prior to further use. (4) Remove any foreign objects that might be attached to it. B. Every 6 Months (1) Inspect the pump cables for signs of wear and or deterioration. (2) Wash the pump with tap water. Pay particular attention to the impeller area, and completely remove any debris from the impeller. (3) Inspect the pump exterior; verify that there is no damage, and that the bolts and nuts have not loosened. (4) If the pump must be disassembled for repair due to damage or loose bolts or nuts, contact the local pump manufacturer's service office. (5) Check the mechanical seal every six months. If you notice water mixed with the oil or cloudy texture of the oil, these may be indications of a defective mechanical seal requiring replacement. (6) CAUTION: Repair work on explosion proof motors may only be performed by approved workshops. Otherwise the "ex" approvals will no longer apply. C. Yearly (1) The service life of the mechanical seal can be prolonged by replacing the oil in the mechanical seal chamber once a year. (2) Refer to the specific manual for the particular pump for addition yearly maintenance adjustments and directions. (3) Parts that need to be replaced: • Mechanical Seal — Whenever oil in mechanical seal chamber is clouded. • Oil filler plug gasket — Whenever oil is replaced or inspected. • Lubricating oil — Whenever clouded or dirty • 0-ring — Whenever pump is overhauled. 4 NAVIX Anthology of Edmonds Page 51 STORMWATER SITE PLAN R MTEC 1.01 RECOMMENDED MAINTENANCE & SPARE PARTS 4. Recommended Spare Parts A. The following list is the parts that Romtec Utilities recommends be on hand for maintenance personnel. These parts are typically not supplied by Romtec Utilities with the system. Contact Romtec Utilities if there is a question regarding supply. (1) Fuses (2) Relays (3) Push Button (4) HOA Switches (5) Lamps (6) Replacement Level Sensor(s) 5 NAVIX Anthology of Edmonds Page 52 STORMWATER SITE PLAN RO MTEC 1.02 OPERATION The following information identifies the correct operational procedure for the pump station as designed by Romtec Utilities. The operational procedure described in this section refers to a system incorporating the following attributes: • Primary Controller: • Primary Level Sensing: • Secondary Level Sensing: • Pump Type: 1. Wet Wells and vaults can be classified as confined spaces depending on relative size and ventilation. Take proper precautions and use the "buddy system". 2. Avoid pinch points when opening and closing hatch lids by wearing gloves and using lid handles. 3. Romtec Utilities recommends leaving safety grates dosed as much as possible when hatch lids are open. 4. Romtec Utilities recommends having qualified personnel or licensed electricians perform work behind the control panel dead front. S. Know what type of medium is being distributed. Take all necessary precautions when dealing with equipment exposed to the pumping medium. 114AA Nate: The pictures below are n2l; project specific. These pictures are included to help identify commonly used control panel operators. i►uir r sc.vr t �uNwo e�o�+to • Push Bu Operal ft 6 NAVIX Anthology of Edmonds Page 53 STORMWATER SITE PLAN R MTEC 1.02 OPERATION I rya 1� J Main Panel Disconnect • O O Pump Circuit Breakers (CB) oil a Section 1.0 — Normal Operation In this section, we will describe the necessary procedure to configure the system for a normal operation mode. Under normal circumstances the lift station's operational scheme will be as follows: Note: The 'HOA' (Hand - OFF - Auto) switches are assumed to be in the 'Auto' position, and the rest of the system is assumed to be configured correctly. 1. The well level will rise until the 'Lead Level' is reached and triggers the primary level sensing device. From here one pump will turn on and begin discharging water until the'Stop Level' is reached by the primary level sensing device. At this point, the primary controller will alternate which pump is designated to the 'Lead' position. 2. If the well level surpasses the 'Lead Level' and reaches the 'Lag Level' set point, both pumps will turn on and discharge water until the'Stop Level' is reached by the primary level sensing device. At this point, the primary controller will alternate which pump is designated to the 'Lead' position. 3. If the well level surpasses the 'Lead Level', and the 'Lag Level', and triggers the'High Level' set point, both pumps will turn on, the alarm beacon will be energized, and the alarm horn will sound. The pumps will discharge water until the 'Stop Level' is reached by the primary level sensing device. At this point, the primary controller will alternate which pump is designated to the'Lead' position. Energizing the Control Panel Note: This step makes the assumption that the primary feed to the control panel is energized, and does not require further action to provide the system with power. 7 NAVIX Anthology of Edmonds Page 54 STORMWATER SITE PLAN R ),MTEC 1.02 OPERATION 1. Step 1: Ensure that the main panel disconnect switch is in the 'ON' position. Nate: At this point, the panel should be energized and ready to operate. However, if certain aspects of the system are not functioning as designed, there are smaller control circuit breakers located behind the panel dead front. These circuit breakers should be left on from the time of Romtec Utilities startup, and if found 'off may likely be an indication of an alternate issue. 2. Step 2: Ensure that the feed circuit breakers are In the 'ON' position for all available pumps. 'HOA' Switches 1. Step 1: Ensure that the'HOA' (Hand -Off -Auto) Switches for all pumps are placed in the'Auto' position to allow for normal operation from the intended level sensing device(s). Note: Please see the following information for a definition of 'HOA'switches and their specific functionality options. • HAND - In Hand position, the pump will run manually. In other words, as long as the'HOA' switch is in this position, the corresponding pump will be'ON' and moving water if applicable. As long as the following conditions are met: 3 Phase power is good and the pump is not in a thermal or overload fault state. • OFF - In the OFF position, the pump will not operate under any circumstance. In other words, as long as the 'HOA'switch is in this position, the pump will be removed from the operational queue for the system and not be called to run by the corresponding level sensing device(s). • AUTO - In the Auto position, the pump will be called to operate by the appropriate level sensing device(s). In other words, when the well level reaches the appropriate height to turn on that corresponding pump, the pump will then turn on until the well level reaches the appropriate shut-off point. As long as the following conditions are met: 3 Phase power is good and the pump temperature is not too high. • 1 V e 1_ • �• ♦ 1 1. Ensure that the system is energized correctly (See Section 1.0) 2. Place the'HOA' switch in 'Hand' mode until the desired well level is reached, Note: The 'HOA'switch must be placed back into the 'Auto' position to resume 'Normal Operation' Section 2.0 — Pump Removal from the Wet Well Note: Lockout all pumps prior to removal from the wet well. 1. Locate the Romtec Utilities supplied 'Grip Eye'tool. Note: The 'Grip Eye' is displayed in the image below. 2. Grip Eye should be securely fastened to a lifting chain (or equal), that is connected to an appropriately sized lifting device. &k: If Romtec Utilities'supplied 'Grip Eye'tool is unavailable, the pumps can be removed via an appropriately rated alternative (i.e. grappling hook, lifting hook, etc.) 3. The Grip Eye will then need to be lowered to the stainless steel chain located at the base of the lifting sling assembly. CAUTION: DO NOT LIFT THE PUMP USING THE STAINLESS STEEL CABLE ATTACHED TO THE SECTION OF CHAIN. THIS IS USED ONLY AS A GUIDE FOR THE GRIP EYE TOOL TO REACH THE SECTION OF CHAIN. 4. Ensure that the Grip Eye firmly latches on to one of the chain links, and begin lifting the pump out of the well. Note: Keep tension on the 'Grip Eye' tool throughout the entire duration of the lift Further Note: As the pump is being removed from the wet well, ensure that all power cables and slack from the lifting sling assembly are simultaneously guided out of the wet well. In addition, safety grates provide an excellent location to place the pump for washing. Any excess debris being removed from the pump will then fall back into the wet well. 8 NAVIX Anthology of Edmonds Page 55 STORMWATER SITE PLAN R ),MTEC 1.02 OPERATION Section 2.1 — Setting the Pumps into the Wet Well 1. Locate the 'Grip Eye' tool (or suitable replacement,. Note: Please see section 2.0 for further information. 2. Securely attach 'Grip Eye' tool (or suitable replacement) to the appropriate lifting equipment. N=: Please see section 2.0 for further information. 3. Guide the 'Grip Eye' tool down the lifting sling assembly until the section of stainless steel chain is reached. Firmly lock one of the chain links in the grip eye. At this point, keeping tension on the 'Grip Eye' will ensure a secure connection to begin lowering the pump. 4. Lift the pump and align the 'Guide Claw' over the guide rails in the wet well. At this point, the pump can be lowered down the guide rails to the discharge elbows located at the well base. Note: Please ensure that the pump cables, and lifting sling assembly are simultaneously lowered into the wet well with the pump. Be attentive to avoid damage to cables during this process. S. Ensure that the Flange discharge face is Flush with the Flange face on the discharge elbow. Note: Maneuvering the lifting chain (or strap) may be necessary to move the pump and firmly seat the pump on the discharge elbow. 6. Hang the lifting sling assembly on either the cable hanger assembly (i.e., eye bolt with carabiner) or hook adjacent to the upper guide bar bracket, and secure cables to their original hanging location. 1. Ensure that all isolation valves are in their specified open position for normal operation. Note: The state of each valve should not have changed from the time of Romtec Utilities'startup. 2. Any check valves with indicators (identifying 'Open' or 'Closed' states) should be in their'Closed State' while the system is not in operation. If a check valve is in an 'Open' state during a period that the system is inactive, the check valve jacking screw may be engaged or debris may be holding the check valve Flapper open. • Seal Fail: When the seal fail indicator light (or push button) is illuminated, the pump's internal sensor is activated indicating that the mechanical seal separating the oil chamber has begun to breakdown. This breakdown allows for the intrusion of water into the oil chamber. If the seal becomes more of an intermittent fault, the pump will need to be serviced and possibly have the seals replaced. • Thermal Fault: When the thermal fault indicator light (or push button) is illuminated, the pump's internal thermal sensor is activated. Note: A Thermal Fault is a "lock out" fault. In other words, as long as this fault is present the pump will be locked out of operation. The presence of this fault is an indication that the pump's internal temperature has reached a point beyond its specified trip value. Possible causes of this issue could be that the pump has been running for an extended period of time in a dry wet well. To reset the Thermal Fault signal latch, press the push button operator. However, the fault may continue to trip if the temperature of the pump is still above the threshold. 9 NAVIX Anthology of Edmonds Page 56 STORMWATER SITE PLAN 1.02 OPERATION IMLVAIN U T I L I T I E S Overload Fault: When the overload fault indicator light (or push button) is illuminated, the pump overload relay has been trippec. Note: An Overload Fault is a 'lock out" fault. In other words, as long as this fault is present the pump will be locked out of operation. The presence of this fault indicates that the current drawn by the pump exceeded the preset threshold (often times FLA specified by the manufacturer) for a certain time period dependent upon the trip class of the relay. Possible causes of this issue are as follows: 1. Locked rotor (i,e. material is lodged in the pump housing restricting the operation of the pump) 2. Insulation breakdown of pump power cables or internal windings 3. Bad Connection of one or more wires to the pump. Nj2ta: All of the faults mentioned above, with the addition of 'High Level' will be accompanied by the station's alarm beacon as well as audible horn. 1. When should I have my pump serviced if I have a 'Seal Fail' light appear? A'Seal Fail' is a fault that can be intermittent throughout the life of a pump. It is not uncommon for this fault to clear itself for periods of time before reappearing. A good Indication of when to have the seals replaced is when the fault becomes consistent and appears regularly. 2. My pumps are not running, but my control panel is energized and the system is either in 'Hand' mode or'Auto' and the well level is at a'Lead' or'Lag'set point. Verify that the feed circuit breakers (CBs) are 'On' and not in a'tripped' position. When the circuit breakers have tripped, their physical appearance closely resembles that of a circuit breaker in the 'On' position. To ensure that they are truly on, cycle the CBs completely 'OFF' and back to the'On' position. As long as the following conditions are met: 3 Phase power is good and the pump is not in a thermal or overload fault state. 3. How do I turn off the alarm beacon? The alarm beacon will stay illuminated as long as there is an active alarm present, or an overload or thermal fault has not been physically reset. In other words, while the following items are active: • Power Fault - The incoming power does not satisfy the systems phase monitor. • Pump I Fault - This includes an overload, thermal, or seal fail. • Pump 2 Fault - This includes an overload, thermal, or seal fail. • High Level - The well level has reached the primary level sensor's'high level' set point. 4. What to expect when checking the oil? In a normal state, the oil will be clear. If the oil has turned a cloudy white, then it will need to be changed. This is an indication that the oil chamber has been compromised by the outside liquid. S. I have a stormwater system. What do I need to do differently during the dry season? During the dry season, it is important to "Bump" the pumps periodically. Note: Bumping the pumps is a term used to describe briefly turning the pump on and then back off. As the weather warms, and water begins to evaporate from the wet well, the pumps will sit idle for quite some time. When a submersible pump sits idle for too long, the mechanical seals tend to harden. Then if the pump starts after this time frame the seal can crack and will require replacement. 10 NAVIX Anthology of Edmonds Page 57 STORMWATER SITE PLAN APPENDIX C GEOTECHNICAL REPORT NAVIX Anthology of Edmonds Page 58 Irerracon &e'o R e p or- -t Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 Prepared for: CA Senior Living Holdings, LLC Chicago, IL Prepared by: Terracon Consultants, Inc. Mountlake Terrace, Washington December 20, 2018 CA Senior Living Holdings, LLC 12345 Street Name Chicago, IL 00000 Attn: Mr. Michael Duggan — Vice President of Development P: (312) 248-2091 E: mduggan@ca-ventures.com Re: Geotechnical Engineering Report Edmonds Senior Living 21200 72nd Ave. W Edmonds, Washington Terracon Project No. 81185173 Dear Mr. Duggan: Irerracon GeoReport We have completed the Geotechnical Engineering services for the above referenced project. This study was performed in general accordance with Terracon Proposal No. P81185173 dated October 22, 2018. This report presents the findings of the subsurface exploration and provides geotechnical recommendations concerning earthwork and the design and construction of building foundations, floor slabs, and temporary shoring for the proposed project. Additionally, we provide discussion for stormwater infiltration potential. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this report or if we may be of further service, please contact us. Sincerely, Terracon Consultants, Inc. Zachary L. Koehn, P.E. Senior Staff Engineer David A. Baska, P.E. Senior Engineering Consultant Terracon Consultants, Inc. 21905 64th Ave. W, Suite 100 Mountlake Terrace, WA 98043 P (425) 771 3304 F (425) 771 3549 www.terracon.com REPORT TOPICS INTRODUCTION............................................................................................................. 1 SITECONDITIONS......................................................................................................... 1 PROJECT DESCRIPTION..............................................................................................2 GEOTECHNICAL CHARACTERIZATION...................................................................... 3 GEOTECHNICAL OVERVIEW....................................................................................... 4 EARTHWORK................................................................................................................. 5 SHALLOW FOUNDATIONS...........................................................................................9 DEWATERING AND SUBSURFACE DRAINAGE....................................................... 11 SEISMIC CONSIDERATIONS......................................................................................12 FLOORSLABS.............................................................................................................13 LATERAL EARTH PRESSURES................................................................................. 14 EXCAVATION DESIGN................................................................................................ 16 STORMWATER MANAGEMENT................................................................................. 18 GENERAL COMMENTS............................................................................................... 19 Note: This report was originally delivered in a web -based format. Orange Bold text in the report indicates a referenced section heading. The PDF version also includes hyperlinks which direct the reader to that section and clicking on the GeoReport logo will bring you back to this page. For more interactive features, please view your project online at client.terracon.com. ATTACHMENTS EXPLORATION AND TESTING PROCEDURES PHOTOGRAPHY LOG SITE LOCATION AND EXPLORATION PLANS EXPLORATION RESULTS SUPPORTING INFORMATION Note: Refer to each individual Attachment for a listing of contents. Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 REPORT SUMMARY Topic 1 Project Description Geotechnical Characterization Earthwork Overview Statement 2 1 rerracon GeoReport Approx. 35,000 square foot development for a senior living facility with six -stories above ground and one below. Assumed Max. Column loads: 500 kips Assumed Max. Wall loads: 6 kips per linear foot Assumed Slab -on -grade: 150 pounds per square foot Pavements do not appear to be part of the planned development Existing fill and recessional outwash soils over glacial till: Loose to dense silty sandy and sandy silt with variable gravel to about 15 feet Dense to very dense glacially consolidated soils to at least 26'h feet Cobbles may be present in glacial soils Groundwater was encountered at about 25 feet below ground surface though perched groundwater may be present shallower The planned development will include removal of topsoil, existing fill, and loose recessional soils. As a minimum, topsoil encountered within proposed driveway or sidewalk subgrades should be removed. Dense, glacially consolidated soils are suitable for foundation subgrades Foundation soils are moisture sensitive and may become unstable when exposed to excessive moisture or are disturbed Shallow foundations will be sufficient Allowable bearing pressure (spread and wall footings) _ Shallow Dense, Native Soil: 5,000 Ibs/sq ft Foundations Below -Grade Structures Shoring Design General Comments Expected settlements: < 1 inch total, <'/2 inch differential Detect and remove zones of unsuitable subgrade as noted in earthwork The planned development includes one level of below grade parking therefore temporary shoring is required Temporary shoring using either cantilevered soldier piles or soldier piles with a single row of tiebacks with 4-inch temporary wood lagging This section contains important information about the limitations of this geotechnical 1. If the reader is reviewing this report as a pdf, the topics above can be used to access the appropriate section of the report by simply clicking on the topic itself. 2. This summary is for convenience only. It should be used in conjunction with the entire report for design Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living 21200 72nd Ave. W Edmonds, Washington Terracon Project No. 81185173 December 20, 2018 INTRODUCTION This report presents the results of our subsurface exploration and geotechnical engineering services performed for the proposed Edmonds Senior Living project to be located at 21200 72nd Ave. W in Edmonds, Washington. The purpose of these services is to provide information and geotechnical engineering recommendations relative to: Subsurface soil conditions Groundwater conditions Site preparation and earthwork Foundation design and construction Floor slab design and construction Seismic considerations and liquefaction Lateral earth pressures Excavation design Stormwater Management The geotechnical engineering scope of services for this project included the advancement of number soil borings to depths ranging from approximately 21 '/2 to 26 '/2 feet below existing site grades, respectively. Maps showing the site and exploration locations are shown in the Site Location and Exploration sections, respectively. The results of the laboratory testing performed on soil samples obtained from the site during the field exploration are included on the boring logs and/or as separate graphs in the Exploration Results section of this report. SITE CONDITIONS The following description of site conditions is derived from our site visit in association with the field exploration and our review of publicly available geologic and topographic maps. Item Description The project is located at 21200 72nd Ave. W in Edmonds, Washington. Parcel Information Lot Size: 35, 284 ft2 (0.81 acres) Latitude: 47.8067 Longitude:-122.3307 See Site Location Responsive ■ Resourceful ■ Reliable 1 Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeoReport Item Description Existing The site is currently developed with a single -story medical office of Improvements approximately 6,641 ftz . The lot includes paved parking areas and drive lanes to the north and east. Current Ground Primarily paved parking with some planting areas around the building. Several Cover large diameter trees are located along the north, south, and east perimeters of the site. Existing Topography The site is gently sloping with elevation of about 282 feet along the northern (Google Earth) property line to about 374 feet to the south. Near -surface soils were generally fill and recessional glacial outwash Geology consisting primarily of loose to medium dense silty sand. Underlying the fill and outwash is dense to very dense, glacially consolidated silty sandy and sandy silt. PROJECT DESCRIPTION Our initial understanding of the project was provided in our proposal, and to the best of our knowledge, has remained unchanged. The understanding in which our assumptions and recommendations are based is as follows: Item Description Email request for proposal as communicated to Terracon by CA Information Provided Senior living facility test fit (no date or title on document) Edmonds development site offering memorandum prepared by Kidder Mathews (no date on document) The project will include demolition of an existing single -story office structure Project Description and development of a multi -story senior living facility with below ground parking. The development appears to include a courtyard area between the wings. The proposed senior living facility development will include one building with Proposed Structure east and west wings constructed to 6 stories above grade (75 feet) with one level of below grade parking (14 feet). Building Construction Wood frame over concrete basement (Assumed) Finished Floor Finished floor elevation is not known at this time Elevation ■ Assumed Max. Column loads: 500 kips Maximum Loads ■ Assumed Max. Wall loads: 6 kips per linear foot ■ Assumed Slab -on -grade: 150 pounds per square foot Grading/Slopes Site grades are not known at this time. Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeoReport Item Description Below Grade Structures The project includes one below -grade level (approximately 14 feet) Free -Standing Retaining Walls Retaining walls are not anticipated as part of site development. (Assumed) Pavements Paved areas do not appear to be part of the planned development Estimated Start of Not known at this time Construction GEOTECHNICAL CHARACTERIZATION We have developed a general characterization of the subsurface soil and groundwater conditions based upon our review of the data and our understanding of the geologic setting and planned construction. The following table provides our geotechnical characterization. The geotechnical characterization forms the basis of our geotechnical calculations and evaluation of foundation options. As noted in General Comments, the characterization is based upon widely spaced exploration points across the site, and variations are likely. Stratum Approximate Depth to Bottom of Stratum (feet) Material Description Asphalt/Concrete Approx. 1 '/2 inch asphalt pavement with 2 inch base course light brown to brown, silty sand with 3'/2 to 7'/2 variable gravel content, some woody debris and cobbles (Fill) grayish brown to brown, sand with 10 to 13 silt content, trace gravel (Recessional Glacial Outwash) gray to dark gray and tan, silty sand at least 26'/2 and sandy silt with variable gravel content (Glacial Till) 1. All borings were terminated in this stratum Consistency/Density N/A loose to medium dense medium dense dense to very dense/hard Conditions encountered at each boring location are indicated on the individual boring logs shown in the Exploration Results section and are attached to this report. Stratification boundaries on the boring logs represent the approximate location of changes in soil types; in situ, the transition between materials may be gradual or vary spatially. Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeoReport Groundwater Conditions The boreholes were observed while drilling and after completion for the presence and level of groundwater. The water levels observed in the boreholes can be found on the boring logs in Exploration Result! , and are summarized below. WM Boring Number B-1, B-2, B-3 B-4 Approximate Depth to Groundwater while Drilling (feet) Not encountered 20 '/2 1. Below ground surface 2. Groundwater is inferred from change in sample moisture 3. Water not present in borehole following extraction of augers Approximate Depth to Groundwater after Drilling (feet) Not encountered 3 Groundwater was not observed borings B-1, B-2, and B-3 while drilling, and was not observed in any boring after extraction of augers for the short duration the borings could remain open. However, this does not necessarily mean the borings terminated above groundwater, or the water levels summarized above are stable groundwater levels. Due to the low permeability of the soils encountered in the borings, a relatively long period may be necessary for a groundwater level to develop and stabilize in a borehole. Long term observations in piezometers or observation wells sealed from the influence of surface water are often required to define groundwater levels in materials of this type. Groundwater level fluctuations occur due to seasonal variations in the amount of rainfall, runoff and other factors not evident at the time the borings were performed. Therefore, groundwater levels during construction or at other times in the life of the structure may be higher or lower than the levels indicated on the boring logs. The possibility of groundwater level fluctuations should be considered when developing the design and construction plans for the project. GEOTECHNICAL OVERVIEW The proposed development will result in about a 14-foot deep excavation to accommodate one level of below grade parking and the building foundations. Although not directly observed in the surface exploration, perched shallow groundwater is commonly present over dense, glacially consolidated soils and therefore may be present during construction. Construction dewatering may be required during excavation and shoring installation. Additionally, the upper 13 feet of the subsurface consists of primarily loose to medium dense cohesionless soils with the potential for a shallow groundwater table. Therefore, the most cost-effective shoring system is likely a cantilever soldier pile or a soldier pile and single row of tiebacks. An easement for temporary Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport, tiebacks will be required from the private properties located on the south and west sides of the project and from the City of Edmonds for anchoring in the public right of way to the north and east. The soils anticipated at the base of the excavation are sufficiently dense for shallow foundations. Casting of foundations may be performed directly onto the existing soils, provided care is exercised during construction to minimize disturbance. Due to the appreciable silt content in these soils, the subgrade could become unstable if not protected from excessive foot and construction traffic, especially after precipitation events. Construction dewatering, if needed, should maintain a dry excavation at least two feet below the foundation subgrade. If possible, construction should be performed during the warmer and drier time of the year. If work is performed during the wet months, an increased risk for possible unstable subgrade, and difficult working conditions, persists. Additional site preparation recommendations are provided in the Earthwork section. The Shallow Foundations and Floor Slabs sections address bearing on native soils, or lean mix concrete if overexcavation is required due to disturbance of the subgrade. Groundwater inflow into the excavation is anticipated to be limited to shallow, perched groundwater zones so inflows are anticipated to be low. Existing fill was observed up to 7'/z feet below ground surface, which is shallower than the depth of the planned excavation; therefore, it is not anticipated that excavation for building foundations or the basement floor slab will encounter fill. Sidewalk and pavement subgrades outside the building may be supported on existing fill materials. However, there is an inherent risk for the owner that compressible fill or unsuitable materials within or buried by the fill will not be discovered. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill but can be reduced by removing the upper foot of fill followed by scarification and recompaction of an additional foot (i.e. total of 2 feet of compacted material below the subgrades). The General Comments section provides an understanding of the report limitations. EARTHWORK Earthwork will include clearing and grubbing, demolition and removal of existing building foundations, and deep excavation to about 14 feet below existing grade, foundation preparation, and utility trenching. The following sections provide recommendations for use in the preparation of specifications for the work. Recommendations include critical quality criteria as necessary to render the site in the state considered in our geotechnical engineering evaluation for foundations, floor slabs, and pavements. Responsive ■ Resourceful ■ Reliable 5 Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeoReport Site Preparation The subgrade should be proof -rolled with an adequately loaded vehicle or construction equipment. The proof -rolling should be performed under the observation of the Geotechnical Engineer. Areas excessively deflecting under the proof -roll should be delineated and subsequently addressed by the Geotechnical Engineer. Such areas should either be removed or recompacted in place. Excessively wet or dry material should either be removed or moisture conditioned and recompacted. For areas outside the proposed excavation, existing vegetation and root mats should be removed prior to placing fill. Complete stripping of the topsoil should be performed for driveway, sidewalk, and parking areas. Existing Fill As noted in Geotechnical Characterization, the surface explorations encountered existing fill. Within the building footprint, the existing fill will be removed as part of the planned excavation. Sidewalks and driveways that are outside the building footprint will encounter fill at the subgrade elevation. These features can be constructed over existing fill, however, there is an inherent risk for the owner that compressible fill or unsuitable material within or buried by the fill will not be discovered. This risk of unforeseen conditions cannot be eliminated without completely removing the existing fill. If the owner elects to construct sidewalks and driveways over the existing fill, at least one -foot below the planned subgrade elevation should completely stripped followed by proof -rolling for the entire area. Areas of soft or otherwise unsuitable material should be undercut and replaced with either new structural fill or suitable, existing on site materials. All subgrades should be field verified by the Geotechnical Engineer to help identify areas with unstable subgrades. These areas should be removed and replaced with suitable fill or recompacted. Fill Material Types Fill required to achieve design grade should be classified as structural fill and common fill. Structural fill is material used below, or within 10 feet of structures, pavements or constructed slopes. Common fill is material used to achieve grade outside of these areas. Earthen materials used for structural and common fill should meet the following material property requirements: Responsive ■ Resourceful ■ Reliable 6 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 Fill Type Recommended Materials 9-03.9(1) Ballast 9-03.9(3) Crushed Surfacing Base Course Structural 9-03.12(1)A Gravel Backfill for Foundations Class A Common Fill 9-03.14(1) Gravel Borrow On -site Soils (Stratum 1 and 2) 1 rerracon GeoReport Acceptable Location for Placement Beneath and adjacent to structural slabs, foundations, and pavement subgrades Grade filling, utility trench backfill outside the building foundation 1. WSDOT Standard Specifications 2. Structural and common fill should consist of approved materials free of organic matter and debris. Frozen material should not be used, and fill should not be placed on a frozen subgrade. A sample of each material type should be submitted to the Geotechnical Engineer for evaluation prior to use on this site. May contain local areas of higher fines content that could make this material moisture sensitive. Particles with a nominal diameter greater than about 3 inches should be removed. Section 9-03.14(3) Common Borrow On -site Soils (Stratum 1 and 2) Fill Compaction Requirements Structural and common fill should meet the following compaction requirements. Item Structural Fill Common Fill 8 inches or less in loose thickness when heavy, Maximum Lift self-propelled compaction equipment is used Thickness 4 to 6 inches in loose thickness when hand- Same as Structural fill guided equipment (i.e. jumping jack or plate compactor) is used Minimum Compaction 95% of maximum dry density Same as Structural fill Requirements Water Content Typically within 2/o o of optimum As required to achieve min. Range compaction requirements Maximum density and optimum water content as determined by the modified Proctor test (ASTM D 1557). Utility Trench Backfill All trenches should be wide enough to allow for compaction around the haunches of the pipe, or material such as pea gravel (provided this is allowed by the pipe manufacturer) should be used below the spring line of the pipes to eliminate the need for mechanical compaction in this portion of the trenches. If water is encountered in the excavations, it should be removed prior to fill placement. Responsive ■ Resourceful ■ Reliable 7 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport, Placement and compaction of recommended materials for utility trench backfill should be in accordance with the recommendations presented herein for Earthwork. In our opinion, the initial lift thickness should not exceed one foot unless recommended by the manufacturer to protect utilities from damage by compacting equipment. Light, hand -operated compaction equipment in conjunction with thinner fill lift thicknesses may be utilized on backfill placed above utilities if damage resulting from heavier compaction equipment is of concern. Flexible connections for utilities that pass through building foundations are recommended to reduce potential stress associated with differential settlement that may occur between the building foundation and the improvements located outside of the building footprint. Earthwork Construction Considerations Upon completion of filling and grading, care should be taken to maintain the subgrade water content prior to construction of floor slabs. Construction traffic over the completed subgrades should be avoided. The base of the excavation should also be graded to prevent ponding of surface water on the prepared subgrades or in excavations. Water collecting over, or adjacent to, construction areas should be removed. If the subgrade freezes, desiccates, saturates, or is disturbed, the affected material should be removed, or the materials should be scarified, moisture conditioned, and recompacted, prior to construction. Construction dewatering is discussed in Excavation Design. Construction Observation and Testing The earthwork efforts should be monitored under the observation of the Geotechnical Engineer. Each lift of compacted fill should be tested, evaluated, and reworked as necessary until approved by the Geotechnical Engineer prior to placement of additional lifts. Each lift of fill should be tested for density and water content. In areas of foundation excavations, the bearing subgrade should be evaluated by the Geotechnical Engineer. In the event that unanticipated conditions are encountered, the Geotechnical Engineer should recommend mitigation options. In addition to the documentation of the essential parameters necessary for construction, the continuation of the Geotechnical Engineer into the construction phase of the project provides the continuity to maintain the Geotechnical Engineer's evaluation of subsurface conditions, including assessing variations and associated design changes. Wet Weather Earthwork The foundation soils at the base of the excavation have variable fines content based on our visual observations and lab testing and are considered moisture sensitive. The suitability of soils used Responsive ■ Resourceful ■ Reliable 8 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport for structural fill depends primarily on their grain -size distribution and moisture content when they are placed. As the fines content (the soil fraction passing the U.S. No. 200 Sieve) increases, soils become more sensitive to small changes in moisture content. Soils containing more than about 5 percent fines (by weight) cannot be consistently compacted to a firm, unyielding condition when the moisture content is more than 2 percentage points above or below optimum. Optimum moisture content is the moisture content at which the maximum dry density for the material is achieved in the laboratory by the ASTM D1557 test procedure. If inclement weather or in situ soil moisture content prevents the use of on -site material as structural fill, we recommend importing granular fill containing less than 5 percent by weight passing the U.S. No. 200 sieve, based on the fraction passing the U.S. No. 4 sieve. Stockpiled soils should be protected with polyethylene sheeting anchored to withstand local wind conditions and preservation of the soil's moisture content. SHALLOW FOUNDATIONS If the site has been prepared in accordance with the requirements noted in Earthwork, the following design parameters are applicable for shallow foundations. Design Parameters — Compressive Loads Description Net allowable bearing pressure ■ Dense/hard, native soil Minimum dimensions Minimum embedment below finished grade 3 Approximate static total settlement from foundation loads for condition specified" Estimated static differential settlement from foundation loads Ultimate passive pressure on native soil Ultimate coefficient of sliding friction Spread Footing 5,000 psf 24 inches 18 inches <1 inch Wall Footing 5,000 psf 18 inches 18 inches <1 inch About 2/3 of total settlement 350 pcf (equivalent fluid unit weight) 0.40 Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport, Description Spread Footing Wall Footing The maximum net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. An appropriate factor of safety has been applied. These bearing pressures can be increased by 1/3 for transient loads unless those loads have been factored to account for transient conditions. Assumes that exterior grades are relatively level adjacent to the structure. Values provided are for maximum loads noted in �. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade soils. For perimeter footing and footings beneath unheated areas. For sloping ground, maintain depth below the lowest adjacent exterior grade within 5 horizontal feet of the structure. 4. Differential settlements are as measured over a span of 50 feet. 5. Use of passive earth pressures require the sides of the excavation for the spread footing foundation to be nearly vertical and the concrete placed neat against these vertical faces or that the footing forms be removed and compacted structural fill be placed against the vertical footing face. 6. Passive resistance in the upper 2 feet of the soil profile should be neglected. 7. Can be used to compute sliding resistance where foundations are placed on suitable soil/materials. Should be neglected for foundations subject to net uplift conditions. Foundation Construction Considerations As noted in Earthwork, the footing excavation subgrades should be observed by the Geotechnical Engineer. The base of all foundation excavations should be free of water and loose soil, prior to placing concrete. Concrete should be placed soon after excavating to reduce bearing soil disturbance. Care should be taken to prevent wetting or drying of the bearing materials during construction. Excessively wet or dry material or any loose/disturbed material in the bottom of the footing excavations should be removed or reconditioned before foundation concrete is placed. If unsuitable bearing soils are encountered at the base of the planned footing excavation, or if prepared subgrades become disturbed through construction activities, the excavation should be extended deeper to suitable soils. The excavation can be backfilled to the planned grade through use of lean concrete as illustrated below. DESIC FOOT REC( EXCF LEAN CONCRETE BACKFILL NOTE: EXCAVATIONS ARE SHOWN VERTICAL, HOWEVER, THE SIDEWALLS SHOULD BE SLOPED AS NECESSARY FOR SAFETY Responsive ■ Resourceful ■ Reliable 10 Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeORepOrt DEWATERING AND SUBSURFACE DRAINAGE We recommend that the walls and parking garage slab are positively drained to collect and convey ground water seepage that may be present. The drainage system should consist of a combination of free -draining structural fill (i.e. material with less than 5 percent passing the No. 200 sieve), wall drainage, footing drains, and a sump collection system if discharge by gravity is not possible. To estimate the steady state flow rate of the under slab and a wall drainage system, further study of groundwater inflows via pump testing and installation of a monitoring wells may be necessary to better estimate the hydraulic conductivity of the foundation soils. For planning purposes, the hydraulic conductivity can be approximated as 10-4 cm per second for the foundation soils, based on particle size analyses. Wall Drainage Basement walls poured flush against the shoring should be provided with drainage by placing full face geocomposite drain against the shoring wall. The geocomposite drain should be tied into the footing drainage system. It is important to provide a good connection between the wall drain and the footing drainage system. The detail of the wall/footing drain connection will depend on the type of shoring, basement wall type, and perimeter footing. Drainage behind walls cast in open excavations can consist of geocomposite drainage as discussed above or a minimum of a 2-foot wide zone of clean sand and gravel fill with less than 5 percent passing the No. 200 sieve. If a moisture -free wall is desired, a water proof barrier, such as plastic or bentonite panels, should be placed over the geocomposite drain prior to pouring or shotcreting the concrete wall. Footing Drains A perimeter footing drain should also be provided and consist of a minimum 4-inch diameter heavy walled perforated PVC pipe or equivalent. We recommend that the footing drains have a minimum slope of 0.25 percent, and that the pipe invert is at least 12-inches below the finish floor slab. The pipe should be bedded in at least 4-inches and surrounded by at least 6-inches, of drainage material consisting of 3/4-inch washed drain rock. We recommend use of nonwoven filter fabric (Mirafi 140N or equivalent) to wrap the entire pipe and rock assembly. Cleanouts are recommended for the footing drain system. Sumps If gravity flow is not possible, the footing and wall drainage system should drain to a sump for pumping. The steady state or long-term groundwater flow rate should be evaluated during construction and the permanent drainage system sized for that flow. If a sump system is used, a backup pump with emergency power is recommended in case of mechanical breakdown. We recommend that the sump and drain pipe clean outs be vented to the atmosphere to prevent the Responsive ■ Resourceful ■ Reliable 11 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport buildup of hydrostatic pressure below the floor slab in case of mechanical or electrical failure of the sump pumps. Dewatering Considerations Construction dewatering is the responsibility of the contractor, who should maintain the excavation and foundation subgrades in a dry condition. Seepage associated with groundwater may be encountered in the excavation for the below grade parking. Based on the results of the subsurface explorations, active dewatering may not be necessary as groundwater was only encountered at about 20 feet below ground surface for B-4 though zones of perched groundwater are typical in similar geologic media. Further study of groundwater inflows via pump testing and installation of monitoring wells may be necessary to better estimate the hydraulic conductivity of retained soils and potential for shallow groundwater. SEISMIC CONSIDERATIONS The seismic design requirements for buildings and other structures are based on the Seismic Design Category. Site Classification is required to determine the Seismic Design Category for a structure. The Site Classification is based on the upper 100 feet of the site profile defined by a weighted average value of either shear wave velocity, standard penetration resistance, or undrained shear strength in accordance with Section 20.4 of ASCE 7-10. Description IValue 1,2 Site Latitude D3 47.8066 Site Longitude-122.3307 Ss — Short Period Spectral Acceleration, Site Class B 4 1.273 g S,-1-Second Period Spectral Acceleration, Site Class B Fa — Short Period Site Coefficient F„-1-Second Period Site Coefficient4 PGA - ASCE 7-10, Peak Ground Acceleration 0.497 g 1.000 1.503 0.516 g FPCA — Peak Ground Acceleration Site Coefficient 1.000 Seismic site classification in general accordance with the 2015 1 BC, which refers to ASCE 7-10. 2015 IBC requires a site profile extending to a depth of 100 feet for seismic site classification. The site properties below the exploration depth to 100 feet were estimated based on our experience and knowledge of geologic conditions of the general area. Site Class D applies to any profile having (1) soils having an average shear wave velocity of 600 to 1,200 feet per sec, (2) an average N value of 15 to 50, (3) an undrained shear strength of 1,000 to 2,000 psf. These values were obtained using online seismic design maps and tools provided by the USGS (http://earthguake.usgs.gov/hazards/designmgps/). Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeORepOrt Surface -Fault Rupture The hazard of damage from onsite fault rupture appears to be low based on review of the Washington Department of Natural Resources Geologic Information Portal available online (https://geologyportal.dnr.wa.gov/#natural hazards) accessed on December 19, 2018. The closest mapped fault is the Southern Whidbey Island fault zone, which is an inferred fault trace, and lies approximately a 1/4 mile to the southwest. Liquefaction Liquefaction is the phenomenon where saturated soils develop high pore water pressures during seismic shaking and lose their strength characteristics. This phenomenon generally occurs in areas of high seismicity, where groundwater is shallow and loose granular soils or relatively non - plastic fine-grained soils are present. Based on the site geology and subsurface groundwater conditions, the risk of liquefaction of the site soils is low for this site during a design level earthquake due to the dense nature of the glacially consolidated soils below the foundation level. FLOOR SLABS Design parameters for floor slabs assume the requirements for Earthwork have been followed. Specific attention should be given to positive drainage away from the structure and. positive drainage of the aggregate base beneath the floor slab. Floor Slab Design Parameters Item Description Floor Slab Support Minimum 6 inches of 9-03.12(4) Gravel Backfill for Drains Compacted to at least 95% of maximum dry density (ASTM D 1557) Estimated Modulus of 160 pounds per square inch per inch (psi/in) for point loads Subgrade Reaction 40 pounds per square inch per inch (psi/in) for all other loading scenarios 1. Floor slabs should be structurally independent of building footings or walls to reduce the possibility of floor slab cracking caused by differential movements between the slab and foundation. 2. Modulus of subgrade reaction is an estimated value based upon our experience with the subgrade condition, the requirements noted in Earthwork, and the floor slab support as noted in this table. 3. WSDOT Standard Specification The use of a vapor retarder is recommended beneath concrete slabs on grade covered with wood, tile, carpet, or other moisture sensitive or impervious coverings, or when the slab will support equipment sensitive to moisture. When conditions warrant the use of a vapor retarder, the slab designer should refer to ACI 302 and/or ACI 360 for procedures and cautions regarding the use and placement of a vapor retarder. Responsive ■ Resourceful ■ Reliable 13 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport, Saw -cut control joints should be placed in the slab to help control the location and extent of cracking. For additional recommendations refer to the ACI Design Manual. Joints or cracks should be sealed with a water -proof, non -extruding compressible compound specifically recommended for heavy duty concrete pavement and wet environments. Where floor slabs are tied to perimeter walls or turn -down slabs to meet structural or other construction objectives, our experience indicates differential movement between the walls and slabs will likely be observed in adjacent slab expansion joints or floor slab cracks beyond the length of the structural dowels. The Structural Engineer should account for potential differential settlement through use of sufficient control joints, appropriate reinforcing or other means. Floor Slab Construction Considerations Finished subgrade within and for at least 10 feet beyond the floor slab should be protected from traffic, rutting, or other disturbance and maintained in a relatively moist condition until floor slabs are constructed. If the subgrade should become damaged or desiccated prior to construction of floor slabs, the affected material should be removed and structural fill should be added to replace the resulting excavation. Final conditioning of the finished subgrade should be performed immediately prior to placement of the floor slab support course. The Geotechnical Engineer should observe the condition of the floor slab subgrades immediately prior to placement of the floor slab support course, reinforcing steel and concrete. Attention should be paid to high traffic areas that were rutted and disturbed earlier, and to areas where backfilled trenches are located. LATERAL EARTH PRESSURES Design Parameters Structures with unbalanced backfill levels on opposite sides should be designed for earth pressures at least equal to values indicated in the following table. Earth pressures will be influenced by structural design of the walls, conditions of wall restraint, methods of construction and/or compaction and the strength of the materials being restrained. Two wall restraint conditions are shown. Active earth pressure is commonly used for design of free-standing cantilever retaining walls and assumes wall movement. The "at -rest" condition assumes no wall movement and is commonly used for basement walls, loading dock walls, or other walls restrained at the top. The recommended design lateral earth pressures do not include a factor of safety and do not provide for possible hydrostatic pressure on the walls (unless stated). Responsive ■ Resourceful ■ Reliable 14 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 S = Surcharge 0 iorizontal -inished 3rade III 1 rerracon GeoReport For active pressure moveme (0.002 H to 0.004 H) For at -rest pressure - No Movement Assumed Horizontal Finished Grade �p2—*—p1Retaining Wall Lateral Earth Pressure Design Parameters Earth Pressure Coefficient for Backfill Uniform Pressure 3, 4, s Effective Fluid Condition 1 Type p, (psf) Pressures (psf) 2, 4, s, s Active Ka 0.31 0.31 S 40 H At -Rest Ko 0.47 0.47 S 60 H Passive K 3.25 --- 350 H (7)H — Active Seismic --- (12)H — At -Rest 1. For active earth pressure, wall must rotate about base, with top lateral movements 0.002 H to 0.004 H, where H is wall height. For passive earth pressure, wall must move horizontally to mobilize resistance. 2. Uniform, horizontal backfill, compacted to at least 92 percent of the ASTM D 1557 maximum dry density, rendering a unit weight of approximately 125 pcf. 3. Uniform surcharge, where S is surcharge pressure. 4. Loading from heavy compaction equipment is not included. 5. No safety factor is included in these values. 6. Values are in addition to static earth pressures Back -fill placed against structures should consist of granular soils or low plasticity cohesive soils. For the granular values to be valid, the granular backfill must extend out and up from the base of the wall at an angle of at least 45 and 60 degrees from vertical for the active and passive cases, respectively. The basement walls connected to multiple floors are best represented by an "at -rest" earth pressure condition due lateral movements of the walls being restrained by the floors. During seismic loading, a moment reduction of up to 80 percent can be applied to basement walls as a result of the stiffer, horizontal floors carrying a higher portion of the seismic load. Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report lrerracon Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 GeORepOrt EXCAVATION DESIGN Based on the soil conditions observed at the exploration locations and the assumed basement floor slab depth of roughly 14 feet below existing grade, we recommend a soldier pile and lagging shoring system to temporarily support the excavation required to construct the below grade portions of the building. Recommendations for soldier piles that are both cantilevered and supported laterally with a single row of tiebacks are provided. Provided adequate distance is available, temporary slope cuts can be combined with the shoring system to reduce the height. The shoring required to support the excavation is typically used as back forms for the permanent basement walls. Terracon should be included in discussions with the design team regarding design of temporary shoring systems for this project and should review the shoring design for compliance with the recommendations for shoring provided in this report. The following design and construction parameters are provided for preliminary planning purposes. Soldier Piles Soldier piles for shoring are typically set in drilled holes and backfilled with lean concrete. If tiebacks are used, structural concrete is placed in the bottom 5 to 10 feet. Soldier pile installation for this site may involve casing the holes and/or drilling with a mud slurry to cut-off groundwater seepage. Passive earth pressures acting on the embedded portion of the soldier piles resist horizontal loads on the shoring system. We recommend using an allowable equivalent fluid unit weight of 350 Ibs per cubic ft. for passive resistance. The passive earth pressure will act over three times the diameter of the concreted soldier pile section, or the pile spacing, whichever is less. The active earth pressures act over the concreted pile diameter below the base of the excavation. A minimum embedment of 10 feet is recommended. For a shoring system with a single row of tieback anchors, we recommend the apparent earth pressure theory for sands (i.e. Figure 24) presented in the Federal Highway Administration Geotechnical Engineering Circular No. 4: Ground Anchors and Anchors Systems (FHWA 1999). For calculating the maximum ordinate of the diagram, P, assume an active earth pressure coefficient of 0.31 and a total unit weight of 125 Ibs per cubic foot (pcf) For traffic loads adjacent to the shoring walls, add a uniform surcharge load equivalent to 250 Ibs per sq. ft; For other loads adjacent to the shoring (e.g., heavy construction loads and building foundations), contact Terracon to estimate appropriate surcharge pressures. Seismic earth pressures are typically not included in shoring design but should be considered if the excavation is to remain open for longer durations. Responsive ■ Resourceful ■ Reliable 16 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport, Vertical capacity of the soldier piles are provided by a combination of end bearing and side friction below the base of the excavation. The piles can be designed for an allowable end bearing capacity and side friction of 20 ksf and 2 ksf, respectively. These values include a factor of safety of 2. Tieback Anchors For tieback anchors, the anchor portion of the tieback should be located sufficiently far behind the excavation shoring to stabilize the excavation face. This "no load" zone is the area behind the soldier pile equal to a lateral distance from the base of the excavation equal to the exposed wall height (H in feet) divided by four, or five feet, whichever is greater, and a line sloping up and back at 60 degrees from horizontal. The selection of the tieback materials and installation methods should be the responsibility of the contractor. The actual adhesion values will depend on the materials and installation method and should be confirmed by testing. For non -pressure grouted anchors, the allowable design concrete/soil adhesion value of 2,000 psf is recommended for the glacially consolidated soils (i.e. bond zone at least about 13 feet below existing ground). For pressure grouted anchors, this value can typically be increased by up to two times. For preliminary design purposes, we recommend an ultimate pullout capacity of 10 kips/foot for 6-inch diameter, secondary pressure grouted anchors. A factor of safety of 2 should be applied to the ultimate pullout capacity. We recommend all tieback anchors be proof tested to at least 130% of the design capacity prior to locking off at the specified post -tensioned design load. Prior to installation of production anchors, two verification tests to 200% of the design pull out capacity are recommended for each soil type in order to confirm the design anchor capacity. The anchor spacing should be at least four feet center to center in order to avoid group effects and the potential for anchors conflict with each other during installation. The anchor holes should be drilled at an angle of 15 to 45 degrees down from horizontal. A minimum anchor bond of 10 feet is recommended. The location and presence of existing features such as utilities should be checked during the design as these may affect the location and length of tieback anchors. Lagging We recommend timber lagging, or some other form of protection, be installed in all areas. Due to soil arching effects, lagging may be design based on the requirements presented in presented in the Federal Highway Administration Geotechnical Engineering Circular No. 4: Ground Anchors and Anchors Systems (FHWA 1999). Prompt and careful installation of lagging would reduce potential loss of ground. The requirements for lagging should be made the responsibility of the shoring subcontractor to prevent soil failure, sloughing, and loss of ground. Proper installation of lagging is critical to provide safe working conditions. We recommend that any voids between the lagging and soil be backfilled promptly. However, the backfill should not allow potential hydrostatic pressure to build-up behind the wall. Drainage behind the wall must be maintained. Voids behind Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport, the lagging should be backfilled immediately with a permeable granular soil material or lean concrete. The excavation height prior to lagging installation should not exceed 4 feet to maintain stability of the cut face. Soldier Pile Shoring Installation The contractor should be required to prevent caving and loss of ground in all soldier pile drill holes. The shoring contractor will need to use methods to minimize caving and sloughing of the drill holes, such as the use of augercast methods or installation of casing. If more than one foot of water is present in the bottom of the hole, placement of concrete from the bottom of the hole using tremie methods will be required. When drilling tieback anchor holes, casing may be required to prevent caving and loss of ground. The anchor grout should be pumped into the anchor zone by tremie methods in order to remove water from the hole and to provide a continuous grouted anchor. Monitoring of Temporary Shoring Any time an excavation is made below the level of existing buildings, utilities, or other structures, there is risk of damage even if a well -designed shoring system has been planned. We recommend, therefore, that a systematic program of observations be conducted on adjacent facilities and structures. The monitoring program should include measurements of the horizontal and vertical movements of the adjacent structures and the shoring system itself. At least two reference lines should be established adjacent to the excavation at horizontal distances backfrom the excavation space of about 1/3H and H, where H is the final excavation height. Monitoring of the shoring system should include measurements of horizontal movements at the top of every other soldier pile. If local wet areas are noted within the excavation, additional monitoring points may be recommended by Terracon. The measuring system used for shoring monitoring should have an accuracy of at least 0.01-feet. All reference points on the existing structures should be installed and readings taken prior to commencing the excavation. All reference points should be read prior to and during critical stages of construction. The frequency of readings will depend on the results of previous readings and the rate of construction. As a minimum, readings should be taken about once a week throughout construction until the basement walls are completed. All readings should be reviewed by Terracon. STORMWATER MANAGEMENT The subsurface conditions were evaluated for infiltration potential for stormwater management. Sieve analyses were performed at 10 and 20 feet bgs for estimating an infiltration rate. In general, Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 Irerracon GeoReport, the soils observed exhibit an appreciable fines content (i.e. percent passing the #200 sieve) which is the soil particle size that largely influences soil permeability. The fines content observed for the soils at these depths are about 15 and 28 percent, respectively. In addition, the soils at these depths are dense to very dense. A soil unit that would be considered favorable for stormwater infiltration was not encountered in any of the borings. Based on particle size analysis alone, an infiltration rate of up to to'/z inch per hour is estimated. However, analysis by particles size does not take soil packing density and is therefore not necessarily representative of in situ conditions. Glacially consolidated soils, such as glacial till, are generally very dense with small amounts of porewater space available. A pilot infiltration study is typical required for evaluating stormwater infiltration potential of glacially consolidated soils. It is unlikely that the results of an infiltration study would conclude that the site is suitable for stormwater infiltration. Therefore, stormwater management via infiltration is not recommended. Onsite storage with tie-in to the City of Edmonds stormwater system should be considered. GENERAL COMMENTS Our analysis and opinions are based upon our understanding of the project, the geotechnical conditions in the area, and the data obtained from our site exploration. Natural variations will occur between exploration point locations or due to the modifying effects of construction or weather. The nature and extent of such variations may not become evident until during or after construction. Terracon should be retained as the Geotechnical Engineer, where noted in this report, to provide observation and testing services during pertinent construction phases. If variations appear, we can provide further evaluation and supplemental recommendations. If variations are noted in the absence of our observation and testing services on -site, we should be immediately notified so that we can provide evaluation and supplemental recommendations. Our Scope of Services does not include either specifically or by implication any environmental or biological (e.g., mold, fungi, bacteria) assessment of the site or identification or prevention of pollutants, hazardous materials or conditions. If the owner is concerned about the potential for such contamination or pollution, other studies should be undertaken. Our services and any correspondence or collaboration are intended for the sole benefit and exclusive use of our client for specific application to the project discussed and are accomplished in accordance with generally accepted geotechnical engineering practices with no third -party beneficiaries intended. Any third -party access to services or correspondence is solely for information purposes to support the services provided by Terracon to our client. Reliance upon the services and any work product is limited to our client, and is not intended for third parties. Any use or reliance of the provided information by third parties is done solely at their own risk. No warranties, either express or implied, are intended or made. Responsive ■ Resourceful ■ Reliable 19 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport Site characteristics as provided are for design purposes and not to estimate excavation cost. Any use of our report in that regard is done at the sole risk of the excavating cost estimator as there may be variations on the site that are not apparent in the data that could significantly impact excavation cost. Any parties charged with estimating excavation costs should seek their own site characterization for specific purposes to obtain the specific level of detail necessary for costing. Site safety, and cost estimating including, excavation support, and dewatering requirements/design are the responsibility of others. If changes in the nature, design, or location of the project are planned, our conclusions and recommendations shall not be considered valid unless we review the changes and either verify or modify our conclusions in writing. Responsive ■ Resourceful ■ Reliable 20 ATTACHMENTS Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 EXPLORATION AND TESTING PROCEDURES Field Exploration Number of Borings Boring Depth (feet) 1 Terracon GeoReport Planned Location B-1 21 '/2 Northeast corner of lot B-2, B-4 26'/2 Northwest, Southeast comers of lot B-3 26'/2 Approx. center of lot Boring Layout and Elevations: Terracon personnel provided the boring layout. Coordinates were obtained with a handheld GPS unit (estimated horizontal accuracy of about ±10 feet). If elevations and a more precise boring layout are desired, we recommend boring locations be surveyed. Subsurface Exploration Procedures: We advanced the borings with a track -mounted, ATV - mounted rotary drill rig using continuous flight hollow -stem augers. Samples were obtained in 5- foot intervals from each boring using a split -barrel sampling procedure. In this procedure, a standard 2-inch outer diameter split -barrel sampling spoon was driven into the ground by a 140-pound automatic hammer falling a distance of 30 inches. The number of blows required to advance the sampling spoon the last 12 inches of a normal 18-inch penetration is recorded as the Standard Penetration Test (SPT) resistance value. The SPT resistance values, also referred to as N-values, are indicated on the boring logs at the test depths. In boring B-2, the boring was inadvertently advanced through a previously abandoned borehole as evident by the hydrated bentonite returned in the auger cutting. Due to time restriction in the day, Terracon elected to drill out the boring until native soils were encountered, which was approximately 18 feet. Sampling, as stated above, was performed at 20 and 25 feet. We observed and recorded groundwater levels during drilling and sampling. All borings were backfilled with granular bentonite after their completion and pavements were patched pre -mixed concrete. The sampling depths, penetration distances, and other sampling information was recorded on the field boring logs. The samples were placed in appropriate containers and taken to our soil laboratory for testing and classification by a Geotechnical Engineer. Our exploration team prepared field boring logs as part of the drilling operations. These field logs included visual classifications of the materials encountered during drilling and our interpretation of the subsurface conditions between samples. Final boring logs were prepared from the field logs. The final boring logs represent the Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 1 of 2 Geotechnical Engineering Report Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport Geotechnical Engineer's interpretation of the field logs and include modifications based on observations and tests of the samples in our laboratory. Laboratory Testing The project engineer reviewed the field data and assigned laboratory tests to understand the engineering properties of the various soil strata, as necessary, for this project. Procedural standards noted below are for reference to methodology in general. In some cases, variations to methods were applied because of local practice or professional judgment. Standards noted below include reference to other, related standards. Such references are not necessarily applicable to describe the specific test performed. ASTM D2216 Standard Test Methods for Laboratory Determination of Water (Moisture) Content of Soil and Rock by Mass ASTM D6913 Standard Test Methods for Particle -Size Distribution (Gradation) of Soils Using Sieve Analysis ASTM D1140 Standard Test Method for determining the Amount of Material Finer than 75-pm (No. 200) Sieve in Soils by Washing The laboratory testing program often included examination of soil samples by an engineer. Based on the material's texture and plasticity, we described and classified the soil samples in accordance with the Unified Soil Classification System. For further soil classification, the following index tests were performed: 5 — ASTM D2216 (Water Content) 3 — ASTM D6913 (Grain Size Distribution) 2 — ASTM D1140 (No. 200 Wash) Responsive ■ Resourceful ■ Reliable EXPLORATION AND TESTING PROCEDURES 2 of 2 SITE LOCATION AND EXPLORATION PLANS Contents: Site Location Plan Exploration Plan Responsive ■ Resourceful ■ Reliable SITE LOCATION Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport 14 n SO OP • C2 .. Ei- --o-� Y ,.14' :l • r l ��'7 IF�, y • •\, .\ 1 i 5- f •,s .11,iSJ'�1 ��II { ' t' •. ;�, I,_+i u�•..r •I �. - -.� It, irw n. 1 •• •�. gills •• ��'.• ` �� i� l r-o:!w S TF e'ta _.� : f -i -�•" S _jam 714 VIZ., J , t Ir I. •�M K ••�N f. -3O. J.9�cr •: • •M '1�-. it • rl it i� � R]�T • ./ r-�• Sfr` .•'x+�.! .� t? } [j �1 � �'• % �• � •� ! q�� . � , ,�r11I-.r- r� � , J ��N1C4 `• • 1 � •ti � Cf �' �� F�i:YMrBn� � . 1 : •► I .' j I I � ; � � • ,-'� � : f • I 1 ` '�, ;' -' •� J 1 1.I ;•. : 'ice �;.' -.. � 'l,.t�.SCk�: :• .:I:r-':�, i+l � `1-= ''I 1 j= -.;1� - ArT i • � ; �' � • •. �.�+` •� •I . �;� ..i • J • ;,I ,`�I' 15��,` 1 I•l�• I �'} `.1 • • lam Ll rr I . • I r-I '. V 'r - "�--r- f (� I • �• ;, , , ♦ Historical Terracon Project , ly )IAGRAM IS FOR GENERAL LOCATION ONLY, AND IS NOT INTENDED FOR CONSTRUCTION PURPOSES MAP PROVIDED BY MICROSOFT BING MAPS EXPLORATION PLAN Edmonds Senior Living Edmonds, Washington December 20, 2018 Terracon Project No. 81185173 1 rerracon GeoReport EXPLORATION RESULTS Contents: Boring Logs (B-1 through B-4) Grain Size Distribution BORING LOG NO. B-1 Pane 1 of 1 I IL of 0 z w U) U) 0 0 2 0 w LU m eo >J 0 z 6 0 J H Q 0 W U PROJECT: Edmonds Senior Living CLIENT: CA Senior Living Holdings, LLC Chicago, IL SITE: 21200 72nd Ave. W Edmonds, WA 0 LOCATION See Exploration Plan J Z w w w O Latitude: 47.8067° Longitude:-122.3303° LL w ¢~ a F F m o w z z F D J W o J w z (If 0 Approximate Surface Elev.: 380 (Ft.) +/- o ¢ M a W EL 2 Ov w ION DEPTH ELEVATFt. O U) a 0.6 ASPHALT, approx. 1.5 inches of asphalt over 2 inches base coarse 379.5+/- SANDY SILT (ML), trace gravel, fine to coarse grained, olive brown to dark brown, moist to wet, soft, trace organics (FILL) 5 12 6-1-5 S-1 N=6 7.5 372.5+/- SILTY SAND (SM), reddish brown to brown, moist, medium dense, (RECESSIONAL OUTWASH) rust staining in top of S-2, possibly evidence of seasonal groundwater 1 18 8-15-16 N=31 S 2 10.5 369.5+/- SANDY SILT (ML), olive gray to gray, moist, very stiff, (GLACIAL TILL) 13.0 367+/- SILTY SAND (SM), trace gravel, gray, moist, very dense 1 16-16 24 trace gravel, dense, interbedded silt 18 N=40 S-3 2 18 11-30-50/6" N=80/12" S-4 14 28 rock fragment in S-4, possibly over -stated blow -count 21.5 358.5+/- Boring Terminated at 21.5 Feet Stratification lines are approximate. In -situ, the transition may be gradual. Hammer Type: Automatic (ETR = 88%) Advancement Method: See Exploration and Testing Procedures for a Notes: Hollow Stem Auger description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. Abandonment Method: Boring backfilled with Auger Cuttings and/or Bentonite Surface Capped with Asphalt Elevations were estimated from Google Earth WATER LEVEL OBSERVATIONS Irerracon Boring Started: 12-05-2018 Boring Completed: 12-05-2018 Drill Rig: D-50track Driller: Holocene 21905 64th Ave W, Ste 100 Mountlake Terrace, WA Project No.: 81185173 BORING LOG NO. B-2 Pane 1 of 1 I EL t7 J C 0 z W z Z 0 0 w J 0 z 6 0 a U) 0 0 PROJECT: Edmonds Senior Living CLIENT: CA Senior Living Holdings, LLC Chicago, IL SITE: 21200 72nd Ave. W Edmonds, WA 0 LOCATION See Exploration Plan z w w ^ rn Lu O Latitude: 47.8067° Longitude:-122.331 ° w �¢ a ~ � F Com D o w z F o Jw w z (If0 Approximate Surface Elev.: 382 (Ft.) +/_ m ¢ m Q W oOf J 2 O w O W a DEPTH ELEVATION Ft. 0.6 ASPHALT, approx. 1.5 inches of asphalt over 2 inches of base coarse 381.5+/- DRILL OUT 5 1 1 20.0 362+/ 2 POORLY GRADED SAND WITH SILT (SP-SM�, light brown to brown, 4-13 25 moist, dense, (GLACIAL TILL) 12 N=38 S-4 22.5 359.5+/- SILTY SAND (SM), reddish brown to olive gray, moist, very dense, silty sand with interbedded silt 2 25-30-36 rust staining in S-5, possibly evidence of seasonal groudwater 18 N=66 S 5 ..26.5 355.5+/- Boring Terminated at 26.5 Feet Stratification lines are approximate. In -situ, the transition may be gradual. Hammer Type: Automatic (ETR = 88%) Advancement Method: See Exploration and Testing Procedures for a Notes: Hollow Stem Auger description of field and laboratory procedures Boring passed through an abandoned borehole of unknown used and additional data (If any). nature. Drill out upper 20 feet due to evidence of borehole See Supporting Information for explanation of symbols and abbreviations. backfill. Abandonment Method: Boring backfilled with Auger Cuttings and/or Bentonite Surface Capped with Asphalt Elevations were estimated from Google Earth WATER LEVEL OBSERVATIONS Irerracon Boring Started: 12-05-2018 Boring Completed: 12-05-2018 Drill Rig: D-50track Driller: Holocene 21905 64th Ave W, Ste 100 Mountlake Terrace, WA Project No.: 81185173 BORING LOG NO. B-3 Pane 1 of 1 'a q J of _0 z III 0 0 2 0 w LU n m eo >J 0 z 6 0 J Q U) 0 Lu PROJECT: Edmonds Senior Living CLIENT: CA Senior Living Holdings, LLC Chicago, IL SITE: 21200 72nd Ave. W Edmonds, WA 0 LOCATION See Exploration Plan J Z w w w O Latitude: 47.8066° Longitude:-122.3307° v w Q~ a Lu Coo w Z z F o w z 0 Approximate Surface Elev.: 378 (Ft.) +/- c ¢ M a W Of 2 Ov w DEPTH ELEVATION Ft. O U) a TOPSOIL + SAND WITH SILT (SP-SM), trace gravel, brown to grayish brown, moist, medium dense, some woody debris and cobbles (FILL) 3.5 374.5+/- SAND WITH SILT (SP-SM), light brown to brown, moist, medium dense, (RECESSIONAL GLACIAL OUTWASH) 5 6 5-6-13 S-1 N=19 increasing silt content, transitions to silty sand 10.0 368+/- 1 SILTY SAND (SM), light brown to brown, moist, dense, (GLACIAL 15-18-13 TILL) 16 N=31 S-2 1 15 10-15-15 S-3 16 13 N=30 rust staining in S-4, possibly evidence of seasonal groundwater 2 18 10-11-21 N_32 S-4 20.5 357.5+/- z1.o SANDY SILT (MLA, reddish brown to olive brown, moist, hard 357+/- SAND (SP), trace silt, brown to reddish brown, moist, dense rust staining in S-5, possibly evidence of seasonal groundwater 2 18 25-33-37 N-70 S-5 .''.•' 25.5 352.5+/- SILTY SAND (SM), gray to dark gray, moist, very dense 26.5 351.5+/- Boring Terminated at 26.5 Feet Stratification lines are approximate. In -situ, the transition may be gradual. Hammer Type: Automatic (ETR = 88%) Advancement Method: See Exploration and Testing Procedures for a Notes: Hollow Stem Auger description of field and laboratory procedures Boring located in landscaped area. u used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. Abandonment Method: Boring backfilled with Auger Cuttings and/or Bentonite Surface Capped with Asphalt Elevations were estimated from Google Earth WATER LEVEL OBSERVATIONS Irerracon Boring Started: 12-05-2018 Boring Completed: 12-05-2018 Drill Rig: D-50 track Driller: Holocene 21905 64th Ave W, Ste 100 Mountlake Terrace, WA Project No.: 81185173 BORING LOG NO. B-4 Pane 1 of 1 'a of 0 z w U) U) 0 0 2 0 w n J J w 0 z 6 0 J Q U) 0 Lu PROJECT: Edmonds Senior Living CLIENT: CA Senior Living Holdings, LLC Chicago, IL SITE: 21200 72nd Ave. W Edmonds, WA 0 LOCATION See Exploration Plan J Z w w w O Latitude: 47.8064° Longitude:-122.3304° v U,a Q~ Lu coo w Z z F o w z 0 Approximate Surface Elev.: 377 (Ft.) +/- c ¢ M a W Of 2 Ov w DEPTH ELEVATION Ft. O rn a ASPHALT, approx. 1.5 inches asphalt over 2 inches base coarse + SILTY SAND WITH GRAVEL (SMI, dark brown with olive brown o mottling, moist, loose, woody debris (FILL) q 12 S-1 5.5 371.5+/- 5 14 2-2-2 N_4 S-2 SILTY SAND (SM), grayish brown to brown, moist, medium dense, sand with silt interbeds (RECESSIONAL GLACIAL OUTWASH) 1 15 7-7-7 S-3 19 15 N=14 13.0 364+/- SAND WITH SILT (SP-SM), light brown to brown, moist, dense to very dense, silt interbeds (GLACIAL TILL) 1 16-27-28 decreasing silt content 17 N=55 S 4 9 6 18.0 359+/- SANDY SILT (ML), light brown, moist, hard rust staining observed in top of S-4, possible evidence of seasonal 20.5 groundwater 356.5+/- 2 18 9N=46 46 S-5 SAND WITH SILT (SP-SMI, trace silt, brown, wet, dense becomes dark gray, very dense 2 17 18-30-36 N=66 S 6 25 89 25.5 351.5+/- SILT ML , trace sand, gray, moist, hard 26.5 350.5+/- Boring Terminated at 26.5 Feet Stratification lines are approximate. In -situ, the transition may be gradual. Hammer Type: Automatic (ETR = 88%) Advancement Method: See Exploration and Testing Procedures for a Notes: Hollow Stem Auger description of field and laboratory procedures used and additional data (If any). See Supporting Information for explanation of symbols and abbreviations. Abandonment Method: Boring backfilled with Auger Cuttings and/or Bentonite Surface Capped with Asphalt Elevations were estimated from Google Earth WATER LEVEL OBSERVATIONS Irerracon Boring Started: 12-05-2018 Boring Completed: 12-05-2018 While sampling Drill Rig: D-50 track Driller: Holocene 21905 64th Ave W, Ste 100 Mountlake Terrace, WA Project No.: 81185173 GRAIN SIZE DISTRIBUTION ASTM D422 / ASTM C136 r 100 95 90 85 80 75 70 65 w 60 >- 55 m ry w 50 z LL 1-- 45 z w 40 w a 35 30 25 20 15 10 5 0 U.S. SIEVE OPENING IN INCHES U.S. SIEVE NUMBERS I HYDROMETER n o 1 a 11) 19 an �n inn ono ME1IIIYIII�■�.ii.�lllwlll■■■IIIIII■■■ IMM UNE Ul�, 100 10 1 0.1 GRAIN SIZE IN MILLIMETERS 0.01 0.001 COBBLES VV��LCJ GRAVEL SAND SILT OR CLAY �� OR Vu+►i coarse fine coarse medium fine Boring ID Depth USCS Classification WC (°io) LL Pq JILPI Cc Cu • B-1 20 - 21.5 silty SAND (SM) m B-4 10 - 11.5 silty SAND (SM) A B-4 25 - 26.5 SILT (ML) Boring ID MaDepth D1oo J D60 D10 %Gravel %Sand %Silt %Fines %Clay 40 B-1 20 - 21.5 19 0.267 0.084 11.8 60.7 27.5 m B-4 10 - 11.5 19 0.249 0.133 2.1 83.4 14.5 A B-4 25 - 26.5 2 0.0 11.2 88.8 PROJECT: Edmonds Senior Living PROJECT NUMBER: 81185173 Irerracon SITE: 21200 72nd Ave. W 21905 64th Ave W, Ste 100 CLIENT: CA Senior Living Holdings, LLC Edmonds, WA Mountlake Terrace, WA Chicago, IL SUPPORTING INFORMATION Contents: General Notes Unified Soil Classification System GENERAL NOTES DESCRIPTION OF SYMBOLS AND ABBREVIATIONS Edmonds Senior Living — Edmonds, WA December 20, 2018 ■ Terracon Project No. 81185173 SAMPLING . WATER LEVEL Water Initially Encountered Standard Grab Penetration Water Level After a Specified Period of Time Sample Test Water Level After a Specified Period of Time Water levels indicated on the soil boring logs are the levels measured in the borehole at the times indicated. Groundwater level variations will occur over time. In low permeability soils, accurate determination of groundwater levels is not possible with short term water level observations. lrerracon GeoReport FIELD TESTS N Standard Penetration Test Resistance (Blows/Ft.) (HP) Hand Penetrometer (T) Torvane (DCP) Dynamic Cone Penetrometer UC Unconfined Compressive Strength (PID) Photo -Ionization Detector (OVA) Organic Vapor Analyzer DESCRIPTIVE SOIL CLASSIFICATION Soil classification is based on the Unified Soil Classification System. Coarse Grained Soils have more than 50% of their dry weight retained on a #200 sieve; their principal descriptors are: boulders, cobbles, gravel or sand. Fine Grained Soils have less than 50% of their dry weight retained on a #200 sieve; they are principally described as clays if they are plastic, and silts if they are slightly plastic or non -plastic. Major constituents may be added as modifiers and minor constituents may be added according to the relative proportions based on grain size. In addition to gradation, coarse -grained soils are defined on the basis of their in -place relative density and fine-grained soils on the basis of their consistency. LOCATION AND ELEVATION NOTES Unless otherwise noted, Latitude and Longitude are approximately determined using a hand-held GPS device. The accuracy of such devices is variable. Surface elevation data annotated with +/-indicates that no actual topographical survey was conducted to confirm the surface elevation. Instead, the surface elevation was approximately determined from topographic maps of the area. STRENGTH TERMS RELATIVE DENSITY OF COARSE -GRAINED SOILS CONSISTENCY OF FINE-GRAINED SOILS (More than 50% retained on No. 200 sieve.) (50% or more passing the No. 200 sieve.) Density determined by Standard Penetration Resistance Consistency determined by laboratory shear strength testing, field visual -manual procedures or standard penetration resistance Descriptive Term Standard Penetration or Descriptive Term Unconfined Compressive Strength Standard Penetration or (Density) N-Value (Consistency) Qu, (tsf) N-Value Blows/Ft. Blows/Ft. Very Loose 0-3 Very Soft less than 0.25 0-1 Loose 4-9 Soft 0.25 to 0.50 2-4 Medium Dense 10 - 29 Medium Stiff 0.50 to 1.00 4-8 Dense 30 - 50 Stiff 1.00 to 2.00 8 - 15 Very Dense > 50 Very Stiff 2.00 to 4.00 15 - 30 Hard > 4.00 > 30 RELATIVE PROPORTIONS OF SAND AND GRAVEL RELATIVE PROPORTIONS OF FINES Descriptive Term(s) of other constituents Percent of Dry Weight Descriptive Term(s) of other constituents Percent of Dry Weight Trace <15 Trace <5 With 15-29 With 5-12 Modifier >30 Modifier >12 GRAIN SIZE TERMINOLOGY PLASTICITY D'ESCRIPTIONlllIIIIIIIIIIIIIIII Major Component of Sample Particle Size Term Plasticity Index Boulders Over 12 in. (300 mm) Non -plastic 0 Cobbles 12 in. to 3 in. (300mm to 75mm) Low 1 - 10 Gravel 3 in. to #4 sieve (75mm to 4.75 mm) Medium 11 - 30 Sand #4 to #200 sieve (4.75mm to 0.075mm High > 30 Silt or Clay Passing #200 sieve (0.075mm) UNIFIED SOIL CLASSIFICATION SYSTEM 1 rerracon Geo—Re port Criteria for Assigning Group Symbols and Group Names Using Laboratory Tests A Coarse -Grained Soils: More than 50% retained on No. 200 sieve Fine -Grained Soils: 50% or more passes the No. 200 sieve Clean Gravels: Gravels: Less than 5% fines c More than 50% of coarse fraction retained on No. 4 sieve Gravels with Fines: More than 12% fines c Sands: 50% or more of coarse fraction passes No. 4 sieve Clean Sands: Less than 5% fines o Cu>_4and 1<_Cc<3E Cu < 4 and/or [Cc<1 or Cc>3.0] E Fines classify as ML or MH Fines classify as CL or CH Cu>_6and 1<_Cc<3E Cu < 6 and/or [Cc<1 or Cc>3.0] E Fines classify as ML or MH Soil Classification Group >ymbol Group Name B GW Well -graded gravel F GP Poorly graded gravel F GM Silty gravel F, G, H GC Clayey gravel F, G, H SW Well -graded sand SP Poorly graded sand SM Silt sand G, H, i Sands with Fines: y More than 12% fines o Fines classify as CL or CH SC Clayey sand G, H, i Inorganic: PI > 7 and plots on or above "A" CL Lean clay K, L, M Silts and Clays: Liquid limit less than 50 I PI < 4 or plots below "A" lines ML Silt K, L, M Organic: Liquid limit - oven dried < 0.75 OL Organic clay K, L, M, N Liquid limit -not dried Organic silt K, L, M, o Silts and Clays: Liquid limit 50 or more Inorganic: PI plots on or above "A" line CH Fat clay K, L, M PI plots below "A" line MH I Elastic Silt K, L, M Organic: Liquid limit - oven dried < 0.75 OH Organic clay K, L, M, P Liquid limit -not dried Organic silt K, L, M, Q Highly organic soils: I Primarily organic matter, dark in color, and organic odor PT Peat A Based on the material passing the 3-inch (75-mm) sieve. H If fines are organic, add "with organic fines" to group name. B If field sample contained cobbles or boulders, or both, add "with cobbles I If soil contains >_ 15% gravel, add "with gravel" to group name. or boulders, or both" to group name. J If Atterberg limits plot in shaded area, soil is a CL-ML, silty clay. c Gravels with 5 to 12% fines require dual symbols: GW-GM well -graded Kif soil contains 15 to 29% plus No. 200, add "with sand" or "with gravel with silt, GW-GC well -graded gravel with clay, GP -GM poorly gravel," whichever is predominant. graded gravel with silt, GP -GC poorly graded gravel with clay. If soil contains >_ plus No. 200 predominantly sand, add o Sands with 5 to 12% fines require dual symbols: SW-SM well -graded name. "sandy" to group name. sand with silt, SW -SC well -graded sand with clay, SP-SM poorly graded sand with silt, SP-SC poorly graded sand with clay. MIf soil contains >_ 30% plus No. 200, predominantly gravel, add 2 "gravelly" to group name. (D 30) H PI >_ 4 and plots on or above "A" line. E Cu = D6o/D,o Cc = o PI < 4 or plots below "A" line. D10 x D60 "A" P PI plots on or above line. F If soil contains >_ 15% sand, add "with sand" to group name. QPl plots below "A" line. G If fines classify as CL-ML, use dual symbol GC -GM, or SC-SM. Irerracon September 18, 2019 CA Senior Living Holdings, LLC 130 E. Randolph St., Ste 2100 Chicago, IL 60601 Attn: Mr. Michael Duggan — Vice President of Development P: (312) 248-2091 E: mduggan@ca-ventures.com Re: Geotechnical Engineering Report — Addendum Letter No. 1 Edmonds Senior Living 21200 72nd Ave. W Edmonds, Washington Terracon Project No. 81185173 Dear Mr. Duggan: This letter serves as an Addendum to the Geotechnical Engineering report dated December 20, 2018 and was developed in general accordance with the Supplement to Agreement for Services (Change Order No. 1) dated September 9, 2019 and your email authorization dated September 10, 2019. We are providing this letter to provide additional geotechnical engineering recommendations for the following: Bearing capacity of shallow foundations for the recessional outwash soil unit Assumptions of groundwater to be used for stability calculations by the structural engineer (KPFF) Temporary slope cuts for soils at the base of the proposed excavation These recommendations are to be used with the geotechnical engineering report stated above. BEARING CAPACITY Our current understanding of the excavation design is based on communication with the shoring designer during a conference call on August 15, 2019. We understand the excavation side wall will vary in elevation such that the dense to very dense glacial till soil unit will be several feet below the planned foundation elevation. To accommodate shallow foundation loading within the medium dense, recessional outwash soil unit, we provided additional bearing capacity recommendations. The table presented below supersedes the table presented in the Shallow Foundations section (i.e. pages 9 and 10) of the geotechnical engineering report: Terracon Consultants, Inc. 21905 64th Ave. W, Suite 100 Mountlake Terrace, WA 98043 P (425) 771 3304 F (425) 771 3549 www.terracon.com Geotechnical Engineering Report — Addendum Letter No. 1 Edmonds Senior Living Edmonds, Washington September 18, 2019 Terracon Project No. 81185173 Description Net allowable bearing pressure Structural fill/medium dense native soil Dense/very dense native soil Minimum dimensions Minimum embedment below finished grade Approximate static total settlement from foundation loads for condition specified Estimated static differential settlement from foundation loads' Ultimate passive pressure Compacted structural fill Spread Footing 3,000 psf 5,000 psf 24 inches 18inches <1 inch Irerracon Wall Footing 3,000 psf 5,000 psf 18inches 18inches <1 inch About 2/3 of total settlement 350 pcf (equivalent fluid unit weight) Ultimate coefficient of sliding friction 0.40 The maximum net allowable bearing pressure is the pressure in excess of the minimum surrounding overburden pressure at the footing base elevation. An appropriate factor of safety has been applied. These bearing pressures can be increased by 1/3 for transient loads unless those loads have been factored to account for transient conditions. Assumes that exterior grades are relatively level adjacent to the structure. Values provided are for maximum loads noted in Project Description. A maximum footing width of 12 feet and 8 feet are assumed for spread and wall footings, respectively. 3. For frost protection and to reduce the effects of seasonal moisture variations in the subgrade soils. For perimeter footing and footings beneath unheated areas. For sloping ground, maintain depth below the lowest adjacent exterior grade within 5 horizontal feet of the structure. 4. Differential settlements are as measured over a span of 50 feet. We should review the settlement estimates after the foundation plan has been prepared by the structural engineer. 5. Use of passive earth pressures require the sides of the excavation for the spread footing foundation to be nearly vertical and the concrete placed neat against these vertical faces or that the footing forms be removed and compacted structural fill be placed against the vertical footing face. 6. Passive resistance in the upper 2 feet of the soil profile should be neglected. 7. Can be used to compute sliding resistance where foundations are placed on suitable soil/materials. Should be neglected for foundations subject to net uplift conditions. Should foundation subgrades within the medium dense, recessional glacial outwash soil unit become overly disturbed, or deleterious soils such as existing fill are identified, replacement of these soils using compacted structural fill can be accomplished per the illustration below and the recommendation provided in the section: Responsive ■ Resourceful ■ Reliable Geotechnical Engineering Report — Addendum Letter No. 1 Irerracon Edmonds Senior Living Edmonds, Washington September 18, 2019 Terracon Project No. 81185173 DESIC FOOTI RECOI EXCP OVER -EXCAVATION / BACKFILL ZONE NOTE: EXCAVATIONS ARE SHOWN VERTICAL; HOWEVER, THE SIDEWALLS SHOULD BE SLOPED AS NECESSARY FOR SAFETY GROUNDWATER AND UNDERVAULT DRAINAGE We understand the City of Edmonds has presented the following comment in the Civil Plan Review for referenced application number BLD20190835 dated August 9, 2019: • Provide Buoyancy calculations to verify that Double check vault will not be affected by groundwater. As discussed, assume groundwater at finish grade, since this area is subject to flooding. Per email communication with KPFF dated August 19, 2019, the City of Edmonds does not consider the site a flood area but that groundwater information is to be provided by the geotechnical engineer (Terracon). In our opinion, an assumed groundwater elevation at finish grade is overly conservative. Based on our observations at the time of the exploratory program, the groundwater present at the site appears to be perched on, and within, the glacial till soil unit. An assumed groundwater elevation at approximately 357 feet would be more appropriate; however, footing drains at the base of the vault should be adequate to collect the groundwater seepage and reduce the likelihood for hydrostatic pressures to build-up against the walls of the vault. Provided the Civil Engineer can design a reliable pumping system to remove the water from the under -vault collection system, the potential for hydrostatic buildup and hence uplift pressure on the vault should be negligible. The Geotechnical Engineer observing the earthwork activities during construction, should be able to confirm, or recommend modifications to, the permanent drainage system. Responsive ■ Resourceful ■ Reliable 3 Geotechnical Engineering Report — Addendum Letter No. 1 Irerracon Edmonds Senior Living Edmonds, Washington September 18, 2019 Terracon Project No. 81185173 TEMPORARY SLOPE CUTS Recommendations for temporary slope cuts were requested by Ankrom Moisan Architects, Inc. (AMA; project architect) via email on August 16, 2019. At the time the geotechnical engineering report was published, we were not aware open cuts were being considered. As a minimum, excavations should be performed in accordance with OSHA 29 CFR, Part 1926, Subpart P, "Excavations" and its appendices, and in accordance with any applicable local, and/or state regulations. The recessional glacial outwash soil unit appears most consistent with OSHA's description for Type C soils. Similarly, the glacial till soil unit appears most consistent with Soil Type B. Construction site safety is the sole responsibility of the contractor who controls the means, methods, and sequencing of construction operations. Under no circumstances shall the information provided herein be interpreted to mean Terracon is assuming responsibility for construction site safety, or the contractor's activities; such responsibility shall neither be implied nor inferred. We appreciate the opportunity to be of service to you on this project. If you have any questions concerning this letter or if we may be of further service, please contact us. Sincerely, Terracon Consultants, Inc. Zachary L. Koehn, P.E. Project Engineer for David A. Baska, P.E. Senior Engineering Consultant Responsive ■ Resourceful ■ Reliable 4 STORMWATER SITE PLAN APPENDIX D STORMWATER PUMP DESIGN INFORMATION NAVIX Anthology of Edmonds Page 59 90111ppw- R MTEC Preliminary Scope of Products and Services - Lift Station Project: Edmonds Senior Living Customer: Contractor Location: Edmonds, Washington Date: February 4, 2022 Page 2 of 6 1.1 Project Overview Romtec Utilities is a design, engineering, and manufacturing firm that specializes in site -specific package pumping systems. For this project, Romtec Utilities is proposing to design and supply a complete packaged stormwater lift station for the Edmonds Senior Living stormwater lift station project. Romtec Utilities based this preliminary scope of work on information and design criteria provided via email by Navix Engineering as of 1/13/2022. This is a complete, packaged stormwater lift station intended to serve Edmonds Senior Living for the purpose of pumping stormwater to the designated discharge manhole. This a privately funded project with the intent of the lift station to be owned and maintained by Edmonds Senior Living. Romtec Utilities shall be solely responsible for the design, supply, performance, and warranty of all package pump station components provided by Romtec Utilities. 1.2 Operational Overview Romtec Utilities has based the preliminary design of the Edmonds Senior Living stormwater lift station on a non - alternating triplex configuration with four (4) floats as the level sensors. In this configuration, each pump will operate at a set elevation to meet the maximum discharge requirements. Edmonds Senior Living stormwater lift station will operate with three (3) individual pumps, each with a force main, and each set to start/stop elevations to achieve 4 GPM, 10 GPM, and 16 GPM discharge rates respectively. Discharge rates will be controlled by adjusting flow using recirculating gate valves. Only one pump will run at a time. The operating pump will be determined by the wet well water level. 2.1 Design and Submittals A. Work shall include designing the structural, mechanical, and electrical pump station components as a complete, pre - designed, packaged system including the following major disciplines: i Structural Design • Wet well, hatch. • Wet well uplift calculations. ii Mechanical Design • pumps, valves, connections, mounting hardware, internal piping. iii Electrical Design • Electrical Equipment including control panel, level sensing. • Romtec Utilities will provide a proposed equipment layout on the engineers site plan in CAD for inclusion in the engineer's plan set for review and approval by the owner. iv Foundation Design • Generator Pad Note: For Romtec Utilities to provide any foundation design, a Geotechnical Report of the site must be provided. B. Design Submittals will be provided in Romtec Utilities' standard electronic format, and Romtec Utilities has included four (4) design revisions as part of the initial pricing. If additional revisions are required, there will be a price increase for the additional design work. C. Romtec Utilities will provide the Operation & Maintenance manual and as -built drawings for the pump station at start- up of the system. O&M manual will include all submittal documentation modified if required, to reflect the as -built condition along with parts lists, maintenance manuals, and electrical schematics. Note: The O&M manuals are not part of the Design Submittals and are not subject to the same comment and revision process. Romtec Utilities will, at its sole discretion, provide updates or revisions to the O&M manual as needed. Regarding as -built plans, Romtec Utilities assumes that the booster station is Romtec Utilities, Inc. 1 18240 North Bank Road I Roseburg, OR 97470 1 541-496-9678 Email: Rusales@romtec.com I www.romtecutilities.com Page 3 of 6 constructed exactly per the Romtec Utilities plans unless specific changes are relayed to Romtec Utilities. Romtec Utilities is not responsible for verifying or certifying any changes to the as -built plans. 2.2 Prefabrication A. Romtec Utilities will fully prefabricate/preassemble the pump station to the extent possible for shipping. B. The wet well prefabrication will include mounting of all discharge elbows, cores/penetrations for the influent and discharge piping, as well as alignment pins/brackets to facilitate simple installation. 2.3 Delivery Services A. The pump station will be delivered on standard flat-bed trucks to be offloaded by the customer or contractor. B. The Installer shall be responsible for coordinating the delivery of the system with Romtec Utilities as well as providing all equipment and labor required for offload. C. Owner or installer will assume responsibility for adequate protection of materials from weather, damage, and pilferage. Otherwise, all warranties expressed or implied may be voided. 2.4 Installation Advisor Services A. An Installation Advisor will be present onsite for one days at the time of underground installation to oversee the delivery of components and provide advisory services for installation of the wet well. B. The Installer shall be responsible for coordinating the required field services with Romtec Utilities. 2.5 System Controls A. Romtec Utilities proposes a specific system control design based on the requirements of the pump station. All Romtec Utilities system control tiers provide robust and reliable operational controls with increasing levels of complexity and customization options at higher tier numbers. B. This system includes a Romtec Utilities Tier 1A system control, which includes a simple relay as the pump control unit. This control design does not require or allow for custom software or programming. This control system will accommodate primary level sensing only (no backup level sensors) and up to six (6) predefined alarm outputs to an optional cellular autodialer. Adjustment of the system operation is primarily accomplished by adjusting the physical placement of the level sensors. 2.6 Electrical Support and Consulting A. Romtec Utilities provides support for the installing electrician over the phone both prior to and during installation of the pump station. 2.7 Start-up/Testing and Owner Training A. After installation, pump station start-up shall be performed by the installing contractor under the supervision of Romtec Utilities' start-up technician. B. The Start-up technician will provide two days of on -site field service. C. During start-up, Romtec Utilities will prove the performance of the system based on the approved Design Submittal, and will provide training to the owner's designated personnel. D. The Startup Technician will complete a field startup report to be provided to Romtec Utilities' customer and the system owner. Note: Romtec Utilities does not guarantee the performance of any aspect of the overall system that is outside Romtec Utilities scope of supply. Romtec Utilities designs the system based on design criteria given by others. In other words, once the system is installed and attached to components, such as a force main, that are outside Romtec Utilities scope of supply, Romtec Utilities does not make any claims as to the performance of the system as a whole. 2.8 Warranty A. The pump station and all its associated components shall be warranted by the OEM and Romtec Utilities and against defects in materials and workmanship for a period of not less than one (1) year from date of final acceptance. Acceptance is defined as the date the Romtec Utilities Field Startup Report is completed. If startup of the installed system is for any reason not performed within six months of installation, the warranty period shall be one year and six months from installation of the pump station. If installation of the delivered pump station is delayed for any reason, the warranty period shall be one year and six months from delivery of the primary structural components, such as the wet well. If delivery is delayed for any reason after the customer agrees to a delivery schedule, the warranty period shall be one year and six months from the date the pump station was ready to deliver. B. Romtec Utilities warranty applies to materials, workmanship, fabrication, and assembly by Romtec Utilities only. Romtec Utilities passes along manufacturers warranties for individual components to the customer and/or owner. Romtec Utilities, Inc. 1 18240 North Bank Road I Roseburg, OR 97470 1 541-496-9678 Email: Rusales@romtec.com I www.romtecutilities.com Page 4 of 6 Some individual component manufacturer warranties may include variances in terms and be shorter or longer than the Romtec Utilities warranty. For example, many pump manufacturers warranties extend beyond the one-year standard warranty offered by Romtec Utilities. C. The Romtec Utilities warranty does not cover issues caused by improper operation and/or maintenance of the system by unqualified personnel. While Romtec Utilities will provide basic operation and maintenance training during system startup, Romtec Utilities is not an ongoing maintenance provider. The owner is responsible for providing qualified operation and maintenance personnel. Romtec Utilities provides technical support and troubleshooting via phone assistance to the owner's qualified onsite system operation and maintenance personnel. Romtec Utilities is not responsible for ongoing training or determining qualifications of operation and maintenance personnel, but Romtec Utilities will review and advise regarding personnel qualifications if requested. D. See attached terms and conditions for more warranty information. 3.2 Estimated Pick Weights A. Wet Well Base - 5,500 lbs. B. Wet Well barrels - 4,000 lbs. C. Wet Well Top Slab - 2,600 lbs. 3.3 Precast Concrete Wet Well and Mechanical Equipment A. Precast 4' diameter wet well and top slab with hatch and cast -in vent B. H-20 occasional traffic rated. C. All cored pipe penetrations with pipe boots as needed (cored holes for electrical conduits are by installer) D. Joint sealant as required E. 2" PVC SCH80 discharge piping F. In -well check valves with manifold G. In -well junction box H. Gate valves I. Protective coating for concrete exterior J. Alignment brackets K. The wet well depth will be 13.73' from the rim to the floor. 3.4 Submersible Pumps A. Three (3) Zoeller N211, 1/2 HP explosion proof, submersible pumps B. Guide rails and brackets C. Pump lifting slings D. The pumps have been quoted with 15' cables 3.5 Level Control System A. Primary: Four (4) floats 3.6 Lift Station Control Panel A. UL listed for the United States B. NEMA 4 painted steel enclosure with an interior "dead" front panel C. Triplex operation D. Hand -off -auto (H.O.A.) switches E. Primary pump control: Control Relay F. Alarm beacon G. Audible alarm H. The control panel and pump station are configured for 240V/Single-phase supply power. 3.7 SCADA/Communications A. The control panel will not include any remote communication devices. B. The control panel will include an alarm beacon and audible alarm for local notification. Romtec Utilities, Inc. 1 18240 North Bank Road I Roseburg, OR 97470 1 541-496-9678 Email: Rusales@romtec.com I www.romtecutilities.com Page 5 of 6 3.8 In -Well ]unction Box A. The in -well junction box will be housed within the precast concrete wet well. B. The junction box will include pump wiring and cable connections and consist of an intrinsically safe junction box for connection to the level sensing. 3.9 Generator and ATS A. 10kW diesel generator will be required for pump station back-up power. B. 24-hour fuel tank C. Sound attenuation level 2 enclosure. D. 125A automatic transfer switch 4.1 Prefabricated Concrete Wet Well and Mechanical A. The wet well will arrive in sections and will need to be "stacked" accordingly in the field. B. Install the discharge piping. The vertical sections of the discharge piping will need to be trimmed in the field to fit. C. Install the pump guide rails. The guide rails will need to be trimmed in the field to fit. 4.2 Pump Package A. Lower the pumps into the wet well at the time of startup. Do not lower the pumps into the wet well until the time of startup. B. The site electrician shall be onsite at the time of startup to finish the wiring of the pumps under the supervision of the Romtec Utilities startup technician. 4.3 Electrical Installation A. All required conduits and site wiring are supplied and installed by the site electrician, not by Romtec Utilities. B. Mounting/Wiring of the Romtec Utilities supplied electrical equipment (control panel, generator, pumps, level sensing). C. Coring of the holes for the electrical conduits in the wet well and/or vaults is the responsibility of the site contractor/electrician. D. The site electrician shall be present all day during the startup of the lift station. The site electrician will need to complete the wiring of the pumps and the level control systems under the supervision of the Romtec Utilities startup technician. 4.4 Generator A. Construction of the generator slab. B. Any required fuel for generator operation. C. Installation of generator fuel tank, exhaust piping, vent piping, and heat exhaust shroud (when applicable). The generator may include some exhaust and/or tank vent piping, but it may not be enough to reach the desired termination point. Contractor is responsible for supply of any additional required piping. 4.5 Romtec Utilities General Exception/Exclusions The following are Romtec Utilities general exceptions/exclusions for this lift station. A. Romtec Utilities is not responsible for determining the methods and equipment used in site preparation or installation. B. Romtec Utilities is not responsible for any required permits, local code compliance, or any related documentation or requirements unless otherwise noted in the preliminary scope letter or the Romtec Utilities Scope of Supply and Design Submittal. C. If a geotechnical report is not provided for the lift station location, then Romtec Utilities makes no guarantees of the lift station structural design. D. Romtec Utilities makes no representation as to how long it will take to prepare the site, install the system, connect the Romtec Utilities, Inc. 1 18240 North Bank Road I Roseburg, OR 97470 1 541-496-9678 Email: Rusales@romtec.com I www.romtecutilities.com Page 6 of 6 system to other equipment not supplied by Romtec Utilities, or to start-up and complete the system. E. Romtec Utilities is not a subcontractor and does not perform any installation or construction tasks at the project site. Romtec Utilities staff at the project site are there strictly to observe and advise. F. Unless notified by the customer, Romtec Utilities sources materials made around the world. "Buy America" requirements must be communicated to Romtec Utilities prior to signing a purchase order or a change order will be issued. G. Romtec Utilities is not responsible for onsite structural or leak testing. Note: Adequate above- and below -grade site drainage is vital for the performance and stability of underground structures, especially in areas of high ground water. Romtec Utilities can provide suggestions regarding site drainage plans, but determination of ground water levels and implementation of site drainage plans is by others, not by Romtec Utilities. Installation of underground structures without an adequate site drainage plan can result in leaks and other damage that is not covered by the Romtec Utilities warranty. H. Actual concrete dimensions will be within +/- 0.5" of the approved production drawing for major dimensions (height, length, width, core locations, wall thickness, etc.). Romtec Utilities will not accept any costs associated with field adjustments or engineered plan revisions based on slight changes to concrete dimensions in the field. I. All access hatches require 50lbs or less of force to open per OSHA requirements unless the hatch is labeled as "two - person lift". J. Romtec Utilities is not responsible for integrating any SCADA equipment with the owner's existing system. K. To ensure timely delivery of the pump system amid ongoing and industry -wide disruptions to shipping, parts/materials availability, and lead times, Romtec Utilities reserves the right make equivalent or better substitutions at any time for any components that are not specifically required to match an exact brand/model. L. Romtec Utilities is not responsible for any of the following: 1. Any fasteners not associated with the pre -assembled systems. 2. Any generator fuel of any kind. 3. Unloading trucks, traffic control, site safety 4. Securing materials delivered to project site: dunnage, fencing, storage 5. Excavation, shoring, dewatering, sub -base rock, backfill material 6. Installation of supplied pump station systems and components 7. Piping to and from pump station. 8. Electrical conduit and wiring (except wires attached to supplied components) 9. Site electrical service/meter equipment 10. Coring of the holes for the electrical conduits in the wet well and valve vaults. 11. Concrete poured in place, crushed rock, asphalt paving 12 Site lighting, signage, fencing, bollards and drainage control Romtec Utilities, Inc. 1 18240 North Bank Road I Roseburg, OR 97470 1 541-496-9678 Email: Rusales@romtec.com I www.romtecutilities.com NOTE: CONDUIT TO CONTROL PANEL (BY OTHERS) MINIMUM: (3) FOR POWER (1) FOR LEVEL SENSING ALL MATERIALS SHOWN ON THIS SHEET WILL BE SUPPLIED BY ROMTEC UTILITIES AND DELIVERED TO THE SITE AFTER THE HOLE HAS BEEN EXCAVATED AND SHORED. THE CONTRACTOR SHALL SUPPLY A CRANE OF SUFFICIENT SIZE TO LOWER ALL THE CONCRETE PIECES INTO THE HOLE SAFELY. THE CONTRACTOR SHALL INSTALL THE WET WELL (AND VALVE VAULT AND METERING VAULT IF APPLICABLE). ROMTEC UTILITIES WILL PROVIDE A REPRESENTATIVE FOR TECHNICAL ASSISTANCE ON THE DAY OF INSTALLATION TO ANSWER ANY QUESTIONS THAT MAY ARISE. THE CONTRACTOR IS RESPONSIBLE FOR ALL PLUMBING AND ELECTRICAL CONNECTIONS AND INSTALLATION. ITEMS NOTED AS "BY OTHERS" WILL BE PROVIDED AND INSTALLED BY THE CONTRACTOR. ROMTEC UTILITIES WILL NOT INSTALL ANY OF THE COMPONENTS SHOWN ON THIS PAGE. TEC © 2022 ROMTEC INC. ALL RIGHTS RESERVED. THESE PLANS AND DRAWINGS MAY NOT BE REPRODUCED, ADAPTED, OR FURTHER DISTRIBUTED, AND NO COMPONENTS MAY BE CONSTRUCTED FROM THESE PLANS, WITHOUT WRITTEN PERMISSION OF ROMTEC, INC. FORCE MAIN & DOWN STREAM MANHOLE (BY OTHERS) SIZE: 2" TYPE: PVC SCH80 OVERFLOW 450 ADJUSTABLE OUTLET/RECIRCULATING \ OVERFLOW 12 PVC(IPS) ELEVATION: 372.59' C.L. DISCHAR, ELEVATION: 2" CHECI FLOOR ELEVATIOI 900 INVERT IN RATED WEIR WALL PRIMARY SENSOR ELEVATION TABLE DESCRIPTION ELEVATION OVERFLOW 372.59' PUMP (3) RUN 372.25 PUMP (2) RUN 368' PUMP (1) RUN 363.25' PUMP STOP 362.62 WELL FLOOR 361.62' MISC. ELEVATION TABLE DESCRIPTION ELEVATION PUMP (2) STOP 372.25' PUMP (1) STOP 368.0' CLEAR HATCH OPENING 28" X 32" LL SECTION B—B SCALE 1 / 18 n I r1TC . SECTION A -A SCALE 1 / 18 T^^ SLAB AN D HATCH ARE TONAL TRAFFIC RATED [ON: 375.35' PUMP PACKAGE o CONFIGURATION: TRIPLEX 0.34' MODEL: ZOELLER N211 4.24' HP: 4/10HP 4.75' 0.63' DUTY POINT: 4GPM @ 363.25' 1.0' 10G PM @ 368.0' 16GPM @ 372.75' FEATURES A r 12 Ti- HATCH: H-20 OCCASIONAL DISCHARGE PIPING: 2" PVC SHC80 PRIMARY LEVEL SENSING: (4) FLOATS BACKUP LEVEL SENSING: N/A STAINLESS STEEL GUIDE RAILS QUICK CONNECT DISCHARGE ELBOWS ADJUSTABLE FLOW VALVES CHECKS W/ MANIFOLD I�T`� III IIII III/ ICI I III IIII III „ � IIII I��y � ,� Ipl`I III II� III °I I�I�I III I �111 III I,I�I ICI°I II I°I11 IIII �I� �I IIII IIII � II � 111I ICI I I II I I � ICI III I III �I�I I r� I I�I�IIII ICI I I II � 111I IIII I III I III I�I`I I III I°II HT �: ==�' I II rIr`t — — — 11 --11 h I. 4 12 L/-----T----- 0 1\J 176 3/4 NOTE: ALL DIMENSIONS AND ELEVATIONS SHOWN ARE NOMINAL DIMENSIONS. IT IS THE RESPONSIBILITY OF THE ON -SITE CONTRACTOR OR ROMTEC UTILITIES CUSTOMER (NOT ROMTEC UTILITIES) TO VERIFY THE ACCURACY OF ANY CRITICAL DIMENSIONS OR ELEVATIONS PRIOR TO SETTING OR INSTALLING ANY EQUIPMENT. �m z c� z 0 o 0- ~ w z o= z 0 Ln Lu N ui ,\I Q N o w ui N J z o�� N Q � U mow (n Sos o Uza� N wu LL za�� 0=a a � o�w < Lu �oMn � 8 Y 0 zz0 0 0 C U o 2 < 00 O O��cri ' 9 Yz j z0M m w = O d- v � Ln Lu o13 0�w2: ,I- Lu • ��a� r, 0 C J z J > Lu oC Q Lu criLu W z W F— O Q L0 L L10 0 z � O °C O 0 LLJ MECHANICAL SHEET ` 2 of 3 J STORMWATER SITE PLAN APPENDIX F STORMWATER COVENANT NAVIX Anthology of Edmonds Page 51 After recording return to: City Clerk City of Edmonds 121 Fifth Avenue North Edmonds, WA 98020 Document Title(s) Declaration of Covenant - Private Stormwater BMP Reference Number(s) of Related Documents City of Edmonds (permit number) BLD2021-0116 Grantor(s) (Last, First and Middle Initial) CA SENIOR EDMONDS WA PROPERTY OWNER, LLC, Grantee: City of Edmonds Legal Description (abbreviated form; i.e., lot, plat or section, township, range, quarter/quarter) SOLNERS 5 ACRE TRACTS BLK 000 D-01 - N 159FT OF LOT 4 LESS W 100FT THOF NW1/4 SEC29 T27N R4E Assessor's Property Tax Parcel/Account Number at the Time of Recording: 005807-000-004-01 The Auditor/Recorder will rely on the information provided on this form. The staff will not read the document to verify the accuracy or completeness of the indexing information provided herein. DECLARATION OF COVENANT Private Stormwater BMP WHEREAS, the undersigned Declarant(s) have installed one or more stormwater facilities under Edmonds Community Development Code (ECDC) Chapter 18.30 known as "stormwater best management practices (BMP)" as selected below: ❑ Permeable Pavement ❑ Infiltration Trench/Gallery/Drywell ® Detention Pipe/Tank/Vault ❑ Concentrated Flow Dispersion ® Other: Stormwater Pump ❑ Infiltration Tank/Vault ❑ Sheet Flow Dispersion ❑ Reduced Impervious Footprint ❑ Rain Garden / Bioretention Cell WHEREAS, the City of Edmonds has allowed installation of the BMP, subject to the execution and recording of this Declaration of Covenant; NOW, THEREFORE, THE UNDERSIGNED DECLARANT(S), being the owners of the real property ("the Property") located at the following address: 21200 72ND AVENUE WEST in the City of Edmonds, Washington, and legally described on Exhibit A attached hereto and incorporated herein by this reference as if set forth in full, hereby covenants and agrees, on behalf of himself/herself/themselves/itself and his/her/their/its successors and assigns, as follows: Declarant(s) warrant that he/she/they/it is/are the owner(s) of the property described on Exhibit A and have the authority to impose this covenant on the property and bind all future owners, successors, and assigns of the Declarant(s). The Declarant(s), future owners, successors, and assigns of the Declarant(s) shall be referred to collectively as "Owners." 2. The Owners of the Property agree that the Property contains one or more stormwater management facilities referred to as a 'BMP," which was installed to mitigate the stormwater quantity and quality impacts of some or all of the impervious or non-native pervious surfaces on the property. a. For infiltration -based BMPs, the BMP shall include all pretreatment devices upstream, the infiltration facility, and a minimum of 3-feet of soil beneath the infiltration contact layer, defined as the elevation at which runoff enters native soils. b. For bio-retention or rain garden BMPs, the BMP shall include all pretreatment devices upstream, the retention facility, the vegetation within the retention facility, and a minimum of 3-feet of soil beneath the infiltration contact layer, defined as the elevation at which runoff enters native soils. While specific plants are not necessarily required, a quantitative amount of vegetation coverage is required and may be subject to maintenance requests per Section 5. c. For dispersion based BMPs, the BMP shall include all pretreatment devices upstream, the dispersion mechanism/device, and all elements of the downstream vegetated flow path, including restrictions on slopes and surface materials, as required by ECDC 18.30. d. For detention BMPs, the BMP shall include all pretreatment devices upstream, the detention device, and the control structure device. e. For reduced impervious footprints, the BMP shall include all areas which are used as mitigation credits, including a full ten foot (10') driveway width when using wheel strip driveways. 3. The Owners shall maintain the size, placement, and design of the BMP as depicted on the approved site plan, Exhibit B, attached hereto and incorporated herein by this reference as if set forth in full, and design details shall be maintained and may not be changed without written approval either from the Engineering Division of the City of Edmonds or through a future development permit from the City of Edmonds. Chemical fertilizers and pesticides shall not be used where a BMP is located. All costs of maintenance and repair shall be the sole responsibility of the Owners. 4. The Owners shall inspect BMPs annually for physical defects. After major storm events, the system shall also be checked to ensure that the overflow system is working properly. The Owners also shall maintain all BMPs so they function as designed on a year-round basis. 5. The City of Edmonds is hereby granted by the Owners the right, but not the obligation, to enter upon the Property described on Exhibit A at all reasonable times for the purpose of inspecting the private stormwater BMP facility. If, as the result of any such inspection, the City of Edmonds determines that the BMP is in disrepair, requires maintenance or repair, or is otherwise not functioning as provided in the site plan, the City Engineer or his designee shall have the right, but not the obligation, to order the Owners to maintain or repair the same. The Owners agree to maintain reasonable one-man access to all portions of the BMP and shall avoid permanent or lockable obstructions from blocking a reasonable path of access by City inspectors. Such obstruction may be the sole cause for the City to request maintenance as noted above. 6. If the City of Edmonds determines that the BMP requires maintenance or repair pursuant to Section 5, the City of Edmonds shall provide notice to the Owners of the deadline within which such maintenance or repair must be completed. Said notice may further advise that, should the Owners fail to perform required maintenance or make repairs within the established deadline, the work may be done by the City or a contractor designated by the City Engineer and the expense thereof shall be charged to the Owners. The City's officers, agents, employees, and contractors shall have the right, which is hereby granted by the Owners, to enter upon the Property described on Exhibit A in order to perform such work. The Owners shall bear the cost of all work performed. 7. The Owners shall indemnify, defend and hold harmless the City of Edmonds, its officers, officials, employees and agents from any and all claims, demands, suits, penalties, losses, damages, judgments, attorneys' fees and/or costs of any kind whatsoever, arising out of or in any way resulting from the approval of the BMP(s), the installation and presence of the BMP(s), and the acts or omissions of the Owners, their officers, employees, contractors, and agents relating to the construction, operation and maintenance of the BMP(s) on the Property, except for the City's intentional and willful tortious acts, and waive and release the City of Edmonds from any and all claims for damages and injunctive relief which the Owners may themselves have now or in the future, by reason of the construction, maintenance and operation of said BMP(s). 8. This covenant shall run with the land and be binding upon the Owners. Dated: DECLARANT(S): APPROVED: CITY OF EDMONDS (Signature) (Title) (Signature) (Print Name) (Print Name) (Title) Corporation STATE OF WASHINGTON ) ss. COUNTY OF ) On this day of , 20, before me, the under -signed, a Notary Public in and for the State of Washington, duly commissioned and sworn, personally appeared to me known to be the of , the corporation that executed the foregoing instrument, and acknowledged the said instrument to be the free and voluntary act and deed of said corporation, for the uses and purposes therein mentioned, and on oath stated that was authorized to execute said instrument and that the seal affixed is the corporate seal of said corporation. WITNESS my hand and official seal hereto affixed the day and year first above written. NOTARY PUBLIC in and for the State of Washington, residing at My commission expires EXHIBIT A PARCEL LEGAL DESCRIPTION THE NORTH 159 FEET OF TRACT 4, SOLNER'S FIVE ACRE TRACTS, ACCORDING TO THE PLAT THEREOF RECORDED IN VOLUME 7 OF PLATS, PAGE 25, RECORDS OF SNOHOMISH COUNTY, WASHINGTON. EXCEPT THE WEST 100 FEET THEREOF. (ALSO KNOWN AS LOT 4 OF CITY OF EDMONDS SHORT PLAT NO. S-20-77, RECORDED UNDER AUDITOR'S FILE NO. 7705310298). SITUATE IN THE COUNTY OF SNOHOMISH, STATE OF WASHINGTON. NW 1/4, NW 1/4, SEC. 29, TWP. 27N., RGE. 4E., W.M. CITY OF EDMONDS, SNOHOMISH COUNTY, WASHINGTON www.axismap.com �paQDD� � l06 NO. DATE 18-210 9/7/21 PO Axi 15241 NE 90TH ST ooOa REDMOND, WA 98052 DRAWN BY CHECKED BY TEL. 425.823-5700 ERM WTB e��op Survey & Mapping FAX 425.823-6700 SCALE SHEET N/A 1 OF Exhibit B Site Plan IN 362.D2 8' PVC E 3]9/2 NW 12' CONC E 379 29 RN 381.90 RIM 38,83 - - - tT' CDN,NC IE T19.]8 W 12' CON, IE 377.63 N --- --- 32' COIE 375.55 NW 30' CONC E 371.21 W 32' COW IE 371.80 E 30' CONC IE 37388 S -f T I Nr H I BRASS DISK R1 u•- .cr. aw SD -SD SO S u \ CONCRETE ! i I wl (BAPS CV BEARINGS] - H _ DOWN O Y 11 CA _ TEN, 'A16) a ►-j-55�-,T�55 'S: SS S5 55 SS 55- WLL A REC -N0. l0 0 I� --- --------------------------------A o G v Lai 50 50 - SO SO SD r—= ` ROd1 0 CONC IE 373 Q,- Q, rt l„, g 3• ELEC' II ' EASO PROPOSED G-FLOOR N 770w 1, SENIOR LIVING FACILITY I > I . o WITH 1-LEVEL I 0 UNDERGROUND PARKING i Z I FFE-382.75 ,04 i N 04 I TRASH AREA y I A RANR LOA \ STAIRS \ STAIRS I I DETENTION VAULT ' STORMWATER rg PUMP I 7-L[--L— o° a1 EL:377.67/ 1 O iD ON S I i S- 7 RE 77 31 10, POWER LINE PARK 2!2 APT LLC EASENENI REC OUMPSTER E7/CL09JRF NC 201810050625 IIIjIj I b' P 1 372. I I I ro 5 3� tOP CIiE 51C 371 1 CAP 'FIRER REB SD561' T CORNER (12/2018) RIN 3]2.05 6' PVC E 371.09 V I N I - Ii �w N •• STORMWATER SITE PLAN APPENDIX F BOND QUANITY WORKSHEET NAVIX Anthology of Edmonds Page 52 Site Improvement Bond Quantity Worksheet S15 Webdate: 04/03/201E LQ King County Department of Permitting & Environmental Review 35030 SE Douglas Street, Suite 210 Snoqualmie, Washington 98065-9266 206-296-6600 TTY Relay 711 Project Name: CA Senior Living Edmonds Location: 21200 72nd Ave W Edmonds, WA 98026 Clearing greater than or equal to 5,000 board feet of timber? yes If yes, Forest Practice Permit Number: (RCW 76.09) Page 1 of 9 Anthology Senior Living_Cost Estimate_220107 x no For alternate formats, call 206-296-6600. Date: 1 /7/2022 Project No.: Activity No.: BLD2021-0116 Note: All prices include labor, equipment, materials, overhead and profit. Prices are from IRS Means data adjusted for the Seattle area or from local sources if not included in the IRS Means database. Unit prices updated: 3/2/2015 Version: 3/2/2015 Report Date: 1/7/2022 Site Improvement Bond Quantity Worksheet S15 Webdate: 04/03/201E Reference # Unit Price Unit Quantity # of Applications Cost EROSION/SEDIMENT CONTROL Number Backfill & compaction -embankment ESCA $ 6.00 CY Check dams, 4" minus rock ESC-2 SWDM 5.4.6.3 $ 80.00 Each 6 1 480 Crushed surfacing 1 1/4" minus ESC-3 WSDOT 9-03.9(3) $ 95.00 CY Ditching ESC-4 $ 9.00 CY Excavation -bulk ESC-5 $ 2.00 CY Fence, silt ESC-6 SWDM 5.4.3.1 $ 1.50 LF 550 1 825 Fence, Temporary (NGPE) ESC-7 $ 1.50 LF 610 1 915 Hydroseeding ESC-8 SWDM 5.4.2.4 $ 0.80 SY Jute Mesh ESC-9 SWDM 5.4.2.2 $ 3.50 SY Mulch, by hand, straw, 3" deep ESCA0 SWDM 5.4.2.1 $ 2.50 SY Mulch, by machine, straw, 2" deep ESCA1 SWDM 5.4.2.1 $ 2.00 SY Piping, temporary, CPP, 6" ESC-12 $ 12.00 LF Piping, temporary, CPP, 8" ESCA3 $ 14.00 LF Piping, temporary, CPP, 12" ESC-14 $ 18.00 LF Plastic covering, 6mm thick, sandbagged ESCA5 SWDM 5.4.2.3 $ 4.00 SY Rip Rap, machine placed; slopes ESCA6 WSDOT 9-13.1(2) $ 45.00 CY 5 1 225 Rock Construction Entrance, 50'x15'x1' ESCA7 SWDM 5.4.4.1 $ 1,800.00 Each 1 1 1800 Rock Construction Entrance, 100'x15'x1' ESCA8 SWDM 5.4.4.1 $ 3,200.00 Each Sediment pond riser assembly ESC-19 SWDM 5.4.5.2 $ 2,200.00 Each Sediment trap, 5' high berm ESC-20 SWDM 5.4.5.1 $ 19.00 LF 80 1 1520 Sed. trap, 5' high, riprapped spillway berm section ESC-21 SWDM 5.4.5.1 $ 70.00 LF 15 1 1050 Seeding, by hand ESC-22 SWDM 5.4.2.4 $ 1.00 SY Sodding, 1" deep, level ground ESC-23 SWDM 5.4.2.5 $ 8.00 SY Sodding, 1" deep, sloped ground ESC-24 SWDM 5.4.2.5 $ 10.00 SY TESC Supervisor ESC-25 $ 110.00 HR 80 1 8800 Water truck, dust control ESC-26 SWDM 5.4.7 $ 140.00 HR WRITE -IN -ITEMS **** (see page 9) Temporary Interceptor Swale $ 15.00 LF 500 1 7500 Inlet Protection $ 250.00 Each 9 1 2250 Temporary Settling Tank $ 10,000.00 Each 1 11 11 10000 ESC SUBTOTAL: 30% CONTINGENCY & MOBILIZATION: ESC TOTAL: COLUMN: Page 2 of 9 Anthology Senior Living_Cost Estimate_220107 $ 35,365.00 $ 10,609.50 $ 45,974.50 A Unit prices updated: 3/2/2015 Version: 3/2/2015 Report Date: 1/7/2022 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right -of -Way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. Cost Quant. Cost GENERAL ITEMS No. Backfill & Compaction- embankment GI - 1 $ 6.00 CY Backfill & Compaction- trench GI - 2 $ 9.00 CY Clear/Remove Brush, by hand GI - 3 $ 1.00 SY Clearing/Grubbing/Tree Removal GI - 4 $ 10,000.00 Acre 0.07 700.00 0.85 8,500.00 Excavation - bulk GI - 5 $ 2.00 CY 13,000.00 26,000.00 Excavation - Trench GI - 6 $ 5.00 CY Fencing, cedar, 6' high GI - 7 $ 20.00 LF Fencing, chain link, vinyl coated, 6' high GI - 8 $ 20.00 LF Fencing, chain link, gate, vinyl coated, 21 GI - 9 $ 1,400.00 Each Fencing, split rail, 3' high GI - 10 $ 15.00 LF Fill & compact - common barrow GI - 11 $ 25.00 CY Fill & compact - gravel base GI - 12 $ 27.00 CY Fill & compact - screened topsoil GI - 13 $ 39.00 CY Gabion, 12" deep, stone filled mesh GI - 14 $ 65.00 SY Gabion, 18" deep, stone filled mesh GI - 15 $ 90.00 SY Gabion, 36" deep, stone filled mesh GI - 16 $ 150.00 SY Grading, fine, by hand GI - 17 $ 2.50 SY Grading, fine, with grader GI - 18 $ 2.00 SY Monuments, 3' long GI - 19 $ 250.00 Each Sensitive Areas Sign GI - 20 $ 7.00 Each Sodding, 1" deep, sloped ground GI - 21 $ 8.00 SY Surveying, line & grade GI - 22 $ 850.00 Day Surveying, lot location/lines GI - 23 $ 1,800.00 Acre 0.07 126.00 0.85 1,530.00 Traffic control crew ( 2 flaggers) GI - 24 $ 120.00 HR 40 4,800.00 Trail, 4" chipped wood GI - 25 $ 8.00 SY Trail, 4" crushed cinder GI - 26 $ 9.00 SY Trail, 4" top course GI - 27 $ 12.00 SY Wall, retaining, concrete GI - 28 $ 55.00 SF Wall, rockery GI - 29 $ 15.00 SF Page 3 of 9 SUBTOTAL *KCC 27A authorizes only one bond reduction. Anthology Senior Living_Cost Estimate_220107 5,626.00 36,030.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 1 /7/2022 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. Cost Quant. Cost ROAD IMPROVEMENT No. AC Grinding, 4' wide machine < 1000sy RI - 1 $ 30.00 SY 325 9,750.00 AC Grinding, 4' wide machine 1000-2000 RI - 2 $ 16.00 SY AC Grinding, 4' wide machine > 2000sy RI - 3 $ 10.00 SY AC Removal/Disposal RI - 4 $ 35.00 SY 100 3,500.00 1475 51,625.00 Barricade, type III ( Permanent) RI - 6 $ 56.00 LF Curb & Gutter, rolled RI - 7 $ 17.00 LF Curb & Gutter, vertical RI - 8 $ 12.50 LF Curb and Gutter, demolition and disposal RI - 9 $ 18.00 LF 120 2,160.00 700 12,600.00 Curb, extruded asphalt RI - 10 $ 5.50 LF Curb, extruded concrete RI - 11 $ 7.00 LF Sawcut, asphalt, 3" depth RI - 12 $ 1.85 LF Sawcut, concrete, per 1" depth RI - 13 $ 3.00 LF Sealant, asphalt RI - 14 $ 2.00 LF Shoulder, AC, ( see AC road unit price ) RI - 15 $ - SY Shoulder, gravel, 4" thick RI - 16 $ 15.00 SY Sidewalk, 4" thick RI - 17 $ 38.00 SY 150 5,700.00 Sidewalk, 4" thick, demolition and dispos RI - 18 $ 32.00 SY 185 5,920.00 375 12,000.00 Sidewalk, 5" thick RI - 19 $ 41.00 SY Sidewalk, 5" thick, demolition and dispos RI - 20 $ 40.00 SY Sign, handicap RI - 21 $ 85.00 Each Striping, per stall RI - 22 $ 7.00 Each Striping, thermoplastic, ( for crosswalk ) RI - 23 $ 3.00 SF Striping, 4" reflectorized line RI - 24 $ 0.50 LF Page 4 of 9 �n ic•>tr_�� *KCC 27A authorizes only one bond reduction. Anthology Senior Living_Cost Estimate_220107 27,030.00 76.225.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 1 /7/2022 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. Cost Quant. Cost ROAD SURFACING No. 4" Rock = 2.5 base & 1.5" top course 9 1/2" Rock= 8" base & 1.5" top course Additional 2.5" Crushed Surfacing RS - 1 $ 3.60 SY HMA 1/2" Overlay, 1.5" RS - 2 $ 14.00 SY HMA 1/2" Overlay 2" RS - 3 $ 18.00 SY 325 5,850.00 HMA Road, 2", 4" rock, First 2500 SY RS - 4 $ 28.00 SY HMA Road, 2", 4" rock, Qty. over 2500 S RS - 5 $ 21.00 SY HMA Road, 3", 9 1/2" Rock, First 2500 S RS - 6 $ 42.00 SY HMA Road, 3", 9 1/2" Rock, Qty Over 25 RS - 7 $ 35.00 SY Not Used RS - 8 Not Used RS - 9 HMA Road, 6" Depth, First 2500 SY RS - 10 $ 33.10 SY HMA Road, 6" Depth, Qty. Over 2500 SY RS - 11 $ 30.00 SY HMA 3/4" or 1 ", 4" Depth RS - 12 $ 20.00 SY 100 125 2,500.00 Gravel Road, 4" rock, First 2500 SY RS - 13 $ 15.00 SY Gravel Road, 4" rock, Qty. over 2500 SY RS - 14 $ 10.00 SY PCC Road (Add Under Write -Ins w/Desi RS - 15 Thickened Edge RS - 17 $ 8.60 LF Page 5 of 9 SUBTOTAL *KCC 27A authorizes only one bond reduction. Anthology Senior Living_Cost Estimate_220107 5,850.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 1 /7/2022 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Cost Quant. I Cost Quant. Cost DRAINAGE (CPP = Corrugated Plastic Pipe, N12 or Equivalent) For Culvert prices, Average of 4' cover was assumed. Assume perforated PVC is same price as solid pipe. Access Road, R/D D - 1 1 $ 21.001 SY Bollards - fixed D - 2 1 $ 240.74 1 Each Bollards - removable D - 3 1 $ 452.34 Each * (CBs include frame and lid) CB Type I D - 4 $ 1,500.00 Each 1 1,500.00 CB Type IL D - 5 $ 1,750.00 Each CB Type II, 48" diameter D - 6 $ 2,300.00 Each 2 4,600.00 6 13,800.00 for additional depth over 4' D - 7 $ 480.00 FT CB Type II, 54" diameter D - 8 $ 2,500.00 Each for additional depth over 4' D - 9 $ 495.00 FT CB Type II, 60" diameter D - 10 $ 2,800.00 Each for additional depth over 4' D - 11 $ 600.00 FT CB Type II, 72" diameter D - 12 $ 3,600.00 Each for additional depth over 4' D - 13 $ 850.00 FT Through -curb Inlet Framework (Add) D - 14 $ 400.00 Each Cleanout, PVC, 4" D - 15 $ 150.00 Each Cleanout, PVC, 6" D - 16 $ 170.00 Each Cleanout, PVC, 8" D - 17 $ 200.00 Each Culvert, PVC, 4" D - 18 $ 10.00 LF Culvert, PVC, 6" D - 19 $ 13.00 LF Culvert, PVC, 8" D - 20 $ 15.00 LF Culvert, PVC, 12" D - 21 $ 23.00 LF Culvert, CMP, 8" D - 22 $ 19.00 LF Culvert, CMP, 12" D - 23 $ 29.00 LF Culvert, CMP, 15" D - 24 $ 35.00 LF Culvert, CMP, 18" D - 25 $ 41.00 LF Culvert, CMP, 24" D - 26 $ 56.00 LF Culvert, CMP, 30" D - 27 $ 78.00 LF Culvert, CMP, 36" D - 28 $ 130.00 LF Culvert, CMP, 48" D - 29 $ 190.00 LF Culvert, CMP, 60" D - 30 $ 270.00 LF Culvert, CMP, 72" D - 31 $ 350.00 LF Page 6 of 9 SUBTOTAL *KCC 27A authorizes only one bond reduction. Anthology Senior Living_Cost Estimate_220107 6,100.00 13,800.00 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 1 /7/2022 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 DRAINAGE CONTINUED Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements No. Unit Price Unit Quant. Cost Quant. Cost Quant. Cost Culvert, Concrete, 8" D - 32 $ 25.00 LF Culvert, Concrete, 12" D - 33 $ 36.00 LF Culvert, Concrete, 15" D - 34 $ 42.00 LF Culvert, Concrete, 18" D - 35 $ 48.00 LF Culvert, Concrete, 24" D - 36 $ 78.00 LF Culvert, Concrete, 30" D - 37 $ 125.00 LF Culvert, Concrete, 36" D - 38 $ 150.00 LF Culvert, Concrete, 42" D - 39 $ 175.00 LF Culvert, Concrete, 48" D - 40 $ 205.00 LF Culvert, CPP, 6" D - 41 $ 14.00 LF 282 3948 Culvert, CPP, 8" D - 42 $ 16.00 LF 321 5136 Culvert, CPP, 12" D - 43 $ 24.00 LF 49 1176 Culvert, CPP, 15" D - 44 $ 35.00 LF Culvert, CPP, 18" D - 45 $ 41.00 LF Culvert, CPP, 24" D - 46 $ 56.00 LF Culvert, CPP, 30" D - 47 $ 78.00 LF Culvert, CPP, 36" D - 48 $ 130.00 LF Ditching D - 49 $ 9.50 CY Flow Dispersal Trench (1,436 base+) D - 50 $ 28.00 LF French Drain (3' depth) D - 51 $ 26.00 LF Geotextile, laid in trench, polypropylene D - 52 $ 3.00 SY Mid -tank Access Riser, 48" dia, 6' deep D - 54 $ 2,000.00 Each Pond Overflow Spillway D - 55 $ 16.00 SY Restrictor/Oil Separator, 12" D - 56 $ 1,150.00 Each Restrictor/Oil Separator, 15" D - 57 $ 1,350.00 Each Restrictor/Oil Separator, 18" D - 58 $ 1,700.00 Each Riprap, placed D - 59 $ 42.00 CY Tank End Reducer (36" diameter) D - 60 $ 1,200.00 Each Trash Rack, 12" D - 61 $ 350.00 Each Trash Rack, 15" D - 62 $ 410.00 Each Trash Rack, 18" 1 D - 63 $ 480.00 1 Each Trash Rack, 21" 1 D - 64 $ 550.00 1 Each Page 7 of 9 SUBTOTAL *KCC 27A authorizes only one bond reduction. Anthology Senior Living_Cost Estimate_220107 10260 Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 1 /7/2022 Site Improvement Bond Quantity Worksheet Web date: 04/03/2015 Existing Right-of-way Future Public Right of Way & Drainage Facilities Private Improvements Unit Price Unit Quant. Price Quant. I Cost Quant. Cost PARKING LOT SURFACING Not To Be Used For Roads Or Shoulders No. 2" AC, 2" top course rock & 4" borrow PL - 1 $ 21.00 SY NA NA 2" AC, 1.5" top course & 2.5" base cour PL - 2 $ 28.00 SY NA NA 4" select borrow PL - 3 $ 5.00 SY NA NA 1.5" top course rock & 2.5" base course PL - 4 $ 14.00 SY NA NA UTILITY POLES & STREET LIGHTING Utility pole relocation costs must be accompanied b Franchise Utility's Cost EstimatE Utility Pole(s) Relocation UP-1 Lump Sum Street Light Poles w/Luminaires UP-2 $ 7,500.00 Each WRITE -IN -ITEMS (Such as detention/water quality vaults.) No. Stormwater Vault WI - 1 $ 140,000.00 Each 1 140,000.00 Stomwater Pump WI - 2 $ 50,000.00 Each 1 50,000.00 Yard Drain WI - 3 $ 250.00 CY 6 1,500.00 WI-4 LF WI-5 FT WI-6 WI-7 WI-8 WI-9 w1-10 SUBTOTAL SUBTOTAL (SUM ALL PAGES): 32,656.00 11,950.00 30% CONTINGENCY & MOBILIZATION: 9,796.80 3,585.00 GRANDTOTAL: 42,452.80 15,535.00 COLUMN: B C Page 8 of 9 *KCC 27A authorizes only one bond reduction. Anthology Senior Living_Cost Estimate_220107 330,315.00 99,094.50 429,409.50 D Unit prices updated: 03/02/2015 Version: 03/02/2015 Report Date: 1 /7/2022 Site Improvement Bond Quantity Worksheet Original bond computations prepared by: Name: Jenelle Taflin, P.E., LEED AP Date: PE Registration Number: 41872 Tel. #: Firm Name: Navix Egineering Address: 11235 SE 6th Street, Suite 150; Bellevue, WA 98004 Project No: Stabilization/Erosion Sediment Control (ESC) Existing Right -of -Way Improvements Future Public Right of Way & Drainage Facilities Private Improvements Calculated Quantity Completed Total Right -of Way and/or Site Restoration Bond*/** (First $7,500 of bond* shall be cash.) Performance Bond* Amount (A+B+C+D) = TOTAL Maintenance/Defect Bond* Total 101/_1LI:9010=-. e]011Zil 7A91 7101 let YiP►1DIi :1bill"INP1 (A) (B) (C) (D) Web date: 04/03/2015 1 /7/2022 425.458.7896 BLD2021-0116 FINANCIAL GUARANTEE REQUIREMENTS PERFORMANCE BOND* MINIMUM BOND* AMOUNT PUBLIC ROAD & DRAINAGE AMOUNT REQUIRED FOR RECORDING OR MAINTENANCE/DEFECT BOND* TEMPORARY OCCUPANCY AT $ 45,974.5 SUBSTANTIAL COMPLETION *** $ 42,452.8 $ 15, 535.0 $ 429,409.5 (A+B) $ 88,427.3 (T) $ 533,371.8 Minimum is $2000. T x 0.30 $ 160,011.5 Minimum is $2000. Jenelle Taflin, P.E., LEED AP (B+C) x 120% = $ 69,585.4 Minimum is $2000. Date: 1 /7/2022 * NOTE: The word "bond" as used in this document means a financial guarantee acceptable to King County. ** NOTE: KCC 27A authorizes right of way and site restoration bonds to be combined when both are required. The restoration requirement shall include the total cost for all TESC as a minimum, not a maximum. In addition, corrective work, both on- and off -site needs to be included. Quantities shall reflect worse case scenarios not just minimum requirements. For example, if a salmonid stream may be damaged, some estimated costs for restoration needs to be reflected in this amount. The 30% contingency and mobilization costs are computed in this quantity. *** NOTE: Per KCC 27A, total bond amounts remaining after reduction shall not be less than 30% of the original amount (T) or as revised by major design changes. REQUIRED BOND* AMOUNTS ARE SUBJECT TO REVIEW AND MODIFICATION BY KING COUNTY Page 9 of 9 Unit prices updated: 03/02/2015 Check out the DDES Web site at www.kinpcounty._poy/permits Version: 03/02/2015 Anthology Senior Living_Cost Estimate 220107 Report Date: 1/7/2022