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20100177 Draft STEP Report 071610
DRAFT S.T.E.P. SYSTEM REPORT FOR SALMON RUN APARTMENTS 10720 VANCIL ROAD SOUTHEAST YELM, WA 98597 Prepared: July 16,2010 By: Cindy Brower, P.E. Coffman Project #10247 L. yy~ Ds 25870 DRAFT Prepared By: ~COFFMAN N G I N E E R S 10 N. Post Street, Suite 500 Spokane, WA 99201 (509)328-2994 f'~I~V J ~) LUI~~ [~ Y: -------------------- ~COFFMAN N G I N E E R S Salmon Run Apartments STEP System Report TABLE OF CONTENTS Project Description ................................. Methodology .......................................... STEP Tank Sizing Calculations ............. STEP Pipelroes ....................................... STEP Pump Assemblies ......................... Conclusions ............................................ ATTACHMEP «A„; «B„ «C„; <<D,>: <<E»; dTS Vicinity Map Geoteclmical Report STEP System Plan STEP Tank Sizing and Pump Calculations References C®FFt~la4N N G I N E E R S PRO.IECT DESCRIPTION Salmon Run Apartments STEP System Repot't The proposed project is located at 10720 Vancil Road SE i^ Yehn, Washington. The on-site improvements consist of the addition of fve (5) new multi-family residential buildings with a total of forty (40) units and one (1) community building. Paved parking lots, sidewalk, playground and landscaped areas are also included in the development. The sanitary sewer improvements will consist of Che City's Septic Tank Effluent Pump (STEP) System, which utilizes tanks for settling and digesting wastewater solids, along with pumps and a pressurized piping system for conveying the liquid into Che City's existing /" force main (located in Vancil Road). This report explains the design of the new STEP system serving the new buildings. The project is located in Yehn in a portion of the southeast r/n and northeast'/a of Section 30, Township 17 Notch, Range 2 East, City of Yelm, W.M. Thurston County, Washington. (See Vicinity Map, Attachment <,A,,,) METHODOLOC>Y The design of this STEP sewer system was based on Che Development Guidelines of the City of Yelm, Chapter 7 -Sanitary Sewer, as well as "The Criteria for Sewage Works Design", August 2008, as published by the Washington State Department of Ecology. This development is for multiple family dwellings (apartments), so 65 gallons/person day was used for the daily sewer flow. Information regarding the use of laundry services was gathered from "Retrofitting Apartment Buildings to Conserve Water: A Guide for Managers, Engineers, and Contractors", May 2002, as published by the U.S. Department of Housing and Urban Development. STEP TANK SIZING CALCULATIONS STEP tanks for each building were sized based on the criteria given in Che Department of Ecology's Criteria for Sewage Works Design, Section CI-10, Alternative Systems. STEP tanks are designed for both Storage Volume (volume of tank above the OFF float) and Detention Volume (volume of tank below the OFF float). Storage volume is calculated as follows: Q= # BEDROOMS X 2 PERSONSBD X 65 GALLONS/PERSON/DAY Detention volume is calculated as follows: V=1.SXQ Total tank volume = Q + V Current on-site code practice assumes two persons bedroom and the estimated daily sewer flow for multiple family dwellings is 65 gallons/persor>/day, as given in Table 2 of the City of Yelm's Development Guidelines. The Community Building (Building F) will include a restroom with one sink and one water closet as well as laundry services. The laundry services will include two laundry sinks, a kitchen sink, and three clothes washers. For purposes of estimating the amount of sewer flow from this building, "Retrofitting Apartment Buildings to Conserve Water: A Guide for Managers, Engineers, and Contractors", May 2002, as published C®FFIiAAN N G I N E E R S Salmon Run STEP System Report by the U.S. Department of Housing mid Urban Development was used. This publication discusses how to calculate water savings when conunon area clothes washers are replaced with high efficiency models. It states: "If the frequency of use [in the laundry facility] is not available, an average of 0.1 cycles per person per day can be used (based on a recent study in Toronto, Canada, on 945 apartments)." Using Table 2 of the City's Development Guidelines, where the estimated daily sewer flow from Laundries, Self-Service is 50 gallons per wash per customer, the following is the calculation used to determine the storage volume required: # OF PERSONS USING LAUNDRY SERVICES = 2 PERSONS/BEDROOM x 96 BEDROOMS IN COMPLEX # OF PERSONS = 192 Q = 50 GALLONS/WASH x 0.1 WASH/PERSON/DAY x 192 PERSONS Q = 960 GALLONS/DAY To determine the storage volume required for the restroom facilities, it was assumed that the daily sewer flow would be similar to a service station aC ] 0 gallons/persor>/day. It was also assumed that half of the residents might use the restroom in a day, a conservative estimation. Storage volume for the restroom was calculated as follows: Q = 10 GALLONS/PERSON/DAY x 192 PERSONS/2 Q = 960 GALLONS/DAY TOTAL Q = 960 + 960 = 1.920 GALLONS/DAY The following is a summary of the volumes required and provided for at each building. TOTAL TANK VOLUME TOTAL TANK REQUIRED VOLUME BUILDING GAL PROVIDED GAL A 8,450 10,000 B 6,500 __ 10,000 (COMBINED WITH BUILDING C 3,250 B D 6,500 16,000 (COMBINED WITH BUILDING E 6,500 D F 4,800 5,000 For specific calculations of tanks shown on the plans, see Appendix "D". 2 COFFnAAN N G I N E E R S STI?P PIPI;LINLS Salmon Run Apartments STEP System Report Sewer flows from individual buildings will be conveyed in 4" PVC gravity lines that will connect to either a STEP Primary Tank or a STEP Pump Taiilc. Flow will continue by gravity from the Primary Tank to a Pump Tank. Effluent will be pumped from all Pump Tanks through a 2"PVC service line to an existing 4" STEP main line in Vancil Road. Per the City's Guidelines, STEP service lines will be installed at a minimum 18" depth on-site. Connection to the existing main line will conform to City specifications. For the STEP system layout, see the STEP System Plan, Appendix "C". STIJP PUMP ASSEMBLIES Since all STEP Pump Tanks for the development are larger than 3000-gallon tanks, duplex pump systems will be used in all STEP Pump Ta~ilcs on-site. Per the City's Development Guidelines, Che pumps will be Orenco PF200511 pumps or equal submersible turbine type, capable of delivering 20 gallons per minute against a Total Dynamic Head (TDH) of 105 feet. For this particular STEP system, a TDH of 12 feet was calculated for Pump Tank #6 (the furthest from the connection in Vancil Road -highest TDH of all pumps on-site). Plotting the system curve on the pump curve for an Orenco PF200511 pump (0.5 HP, 115 volt, single phase, 60 Hz), it was determined that the system curve does not cross the pump curve until it is greater than 30 gpm. An Orenco representative explained that when this happens, they use a 1" discharge assembly instead of the standard 1.25" assembly to apply more head to Che system, Chus alleviating the problem. Downstream of this assembly, a 1" by 2" reducer will be installed to allow for the required 2" service line. See Appendix "D" for pump calculations. STEP Pump Tanks will be fiberglass tanks. In order to achieve H-20 rated loading per Containment Solutions, Inc., tanks require three feet of cover. CONCLUSIONS All STEP tanks and pumps have been sized to adequately serve the new buildings on [his site. ~COFFMAN N G I N E E R S Salmon Run Report VICINITY MAP ATTACHMENT "A" ari VICINITYMAP ATTACHMENT "A" ~COFFMAN NGINEERS Salmon Run Apartments STEP System Report GEOTECHNICAL REPORT ATTACHMENT "B" CEOTECF~t~ICAL REPORT I R E k i salmon Run Apartments 10720 Vancil Road SE Yelm, Washington Project No. Ta6437 T~r~~ ~,,~~~cia~~s, ~~ce Prepared for: TimEaer River E3eveiapment k~ellevue, °~ashington IU~tay 5, 2010 ~ER~tI~ ~,S~C~C1~4T~~, Inc. Consultants in Geotechnical Engineering, Geology and Environmental Earth Sciences May 5, 2010 Project No. T-6437 Mr. Mark Ro~gay Timber River Development 222,3 - ] 12th Avenue NE, Suite 102 13ellewe, Washington 98UU4 Subject: Geotechnical Report Salmon Run Aparltnents 10720 Vancil Road SE Yelm, Washington Dear Mr. Itozgay As requested, we have conducted a geoteclmical engineering study for the subject project, Our field exploration indicates the site is generally underlain by 2 to 2.5 feet of organic fill material overlying variable glacial sediments composed of silty sand, sand with silt. variable gravel content, and gravel with sand. The fill materials are not suitable for the support of the proposed buildings and pavements. The fll materials will need to be removed from structural and pavement subgrades. The attached report presents our findings and recommendations for the geotechnieal aspects of project design and construct ion. We truss the iufonuation presented in this report is sufficient for your current needs. [f you have any questions or require additional inforntation, please call. SJ=I~ 12525 Willows Road, Suite i01, Kirkland, Vdashington 98034 P{tone (A2S) II21-7777 • Fas (425) 821-4334 Sincerely yours, TERRA ASSOCIATES, INC. Carolyn Schepper, E.LT. TABLE OF CONTENTS Paae No. I,0 Project Descripiion .................................................................. ........................................ 1 2.0 Scope of Work ......................................................................... ........................................ 1 3,0 SiteConditious ........................................................................ ........................................2 3.1 Surface ........................................................................ ........................................2 3.2 Subsurface .................................................................. ........................................2 3.3 Groundwater ............................................................... ........................................2 4.0 Geologic llazards .................................................................... ........................................ Z 4.1 Seismic Considerations .............................................. ........................................ Z 4.2 Erosion ....................................................................... ........................................ 3 4.3 Landslide Hazard ........................................................ ........................................ 3 5.0 Discussion and Recommendations .......................................... ........................................ 4 5.1 General ....................................................................... ........................................4 5.2 Site Preparation and Grading ..................................... ........................................4 5.3 Excavations ................................................................ ........................................5 5.4 Foundation Suppon .................................................... ........................................5 5.5 Floor Slab-on-Grade ................................................... ........................................ 6 ~.6 Stonuwater Infiltration Feasibiliq~ ............................. ........................................ 6 5.7 Draiuage ..................................................................... ........................................ 7 S.Ei Utilities ....................................................................... ........................................7 5,9 Pavement .................................................................... ........................................ S G.0 Additional Services ................................................................. ........................................ 3 7.0 Limitations ............................................................................... ........................................ S Eieures Vicinity Map ........................................................................................................................ Figure I Exploration Location Plan .................................................................................................... Figure 2 Appeudis Field Exploration and Laboratory Testing ........................................................................Appendix A Geotechnical Report Salmon Run Apartments 10720 Vancil Road SE Yelm, Washington 1.0 PROJECT D);SCRIPTION The project consists of developing the site with live new apartment buildings, a community building, a play area, and associated parking and utilities. Based nn the conceptual site plan prepared by 7eck Bolter Architects dated September 2, 2003, the buildings mill be located nn the outer edges of the prope,ty with the community building and play area located in the center. 4Ve expect that the apanmeut structures and the recreational building mill be t+vo-story wood-flamed buildings consultc[ed al grade. Structural loading should be relatively Iight; with bearing walls carrying loads of 2 to 3 kips per foot and isolated columns carrying maximum loads of 30 to 40 kips. The reconunendatious in the following sections of this report are based on our uudestandiug of the preceding design features. ~Ve should review design drawings as they become available to verify that our rccommendaliats have been properly interpreted and to supplement them, if required, 2.0 SCOI G Oh V1'ORK Our +vork was completed in accordance +vith our proposal dated July I G, 2009. On April 27, 2010, +ve observed soil conditions at 7 test pits excavated to depths ranging from 3 l0 10 feet below existing grade. Using the in('ormation obtained from the subsurface exploration, we performed analyses to develop geoteclmical recommendations for project design and construction. Specifically, this report addresses the following: • Soil and groundwater conditions • Seismic design parameters per 2006 International Building Code (IBC) • Geologic critical areas • Site preparation and grading Foandatio„s • Flom stabs at grade • Stormwatcr inliluation feasibility • Subsurface drainage • Utilities • Pavements It should be noted that recommendations outlined in this report regarding drainage are associated with soil sut~ugth, design earth pressures, erosion, and stability. Design and performance issues +vith respect to moisture as it relates Io the structure environment (i.e., humidity, mildew, mold) is beyond Tenor Associates' purview. A building envelope specialist or contractor should be consuhed to address these issues, as needed. ,May 5, 2010 Project No. 'T-6437 3.0 SITE CONDI'CK)NS 3.1 Surface The site is located at 10720 Vancil Road in Yelnt, Washington. T'he approximate site location is shown on Figure I , The site is rectangular with a pau handle that extends towards the west, The site is currently undeveloped and is covered with tall grass, brush, small mees, and a few mature tr>res. We observed household rubbish scattered throughout the site. The site is bordered by single-family residences to the south and west, an open field to the east, and a retail center to the north. The site and vicinity are relatively level. The ground surface on the site is uneven suggesting some past grading may have occun'ed. 3.2 Subsurl'acc 1\'c observed 2 to 2.5 feet of organic fill material immediately below existing grades. Beneath the fill mantel, all of our test pits encountered and were terminated within glacial sediments composed of silty scud, sand with silt and a variable gravel content, and gravel with sand. The Geologic ddrq~ of d+e Cenu•alin Quadrangle, N4rshutgtan, by Henry \\'. Schasse (1987), show the site is within an area mapped as "Vashon Outwash Gravel" (Qdvg). Native soil conditions we observed at our test pits are generally consistent with the geologic conditions shown on the map. The preceding discussion is imended to be a general review of the soil conditions encountered. For more detailed descriptions, please refer to the Test Pit Logs in Appendix A. 3.3 Gromrdwater bVe did not observe groundwater seepage in the test pit excavations ai the time of our exploration, We did observe some wet soil conditions suggcstimg areas of shallow seepage possibly develop during the normally wet winter season. However, based on soil conditions and labotatot}~ test results, we expect these areas would be limited in extern. 4.0 GEOLOGICAL HAGARDS 4,1 Seismic Considerations Section 14.OS.130 of the Yehn Municipal Code (YMC) defines Seismic hazard areas as areas subject to severe risk of damage as a result of earthquake induced ground shaking, slope failure, settlement, soil liquefaction, lateral spreading, or surface faulting. Liquefaction is a phenomenon where there is a reduction or cmuplele loss of soil strength due to an increase in water pressure induced by vibrations. Liquefaction mainly affects geologically recent deposits of tine-grained sand that is below the groundwater table. Soils of this nature derive their strength bout intergranular li•iction. The generated water pressure or pore pressure essentially separates the soil grains and eliminates this intergranular friction; thus, eliminating the soil's strength. Page No. 2 \4ay 5, 20 ] 0 Project No. "I'-6437 Based on the soil and groundwater conditions we observed, it is our opinion that the hazards for liquefaction or settlement at this site during an earthquake and their associated risk or impacts are negligible. Based oa soil conditions observed in the test borings and our lurowledge of the area geology, per Chapter 16 of the 2006 International Building Code (IBC). site class "C" should be used in structw'al design. Based on this sift class, in aceordutce with the 2006 IBC, the following parameters should be used in computing seismic forces: Seismic Design Pnratue~w•s (IBC 2006) Spectral response acceleration {Short Period), $< 1.139 SpecUal response acceleration (I -Second Period), S, 0,558 Site coefficient, F, 1.000 Site coefficient, P,. 1.402 Five percent damped .2 sa;wtd period, So< 0.759 Five percent damped 1.0 second period, S~, 0.372 Vahtes determined using the United Slates Geological Survey (USGS) Ground Motion Parameter Calculator accessed on April 28, 2010 at the web site I~ta`e~2r1_7l c~tsakc.u,~~s~a:civ:rzsearelvharmaps~rizsir<nlind~~x.p1,~• 4.2 Crosion Section 14.08.130 of the YMC defines L-rosion hazard areas as areas are at least those areas identified by the U.S. Deparment of Agriculture's \aUiral Resources Conservation Service as having a "moderate to severe," "severe," or "very severe' rill and inter-rill erosion hazard. b'rosion hazard areas are also those areas impacted by shore land and/or stream back erosion and those areas within a river's channel migration zone The soils encowllered on-site are classified as Nisqually loamy line sand and Spanaway gravelly sandy loran by the United States Department of Agriculture Soil Conservation Service Soil Classilicatioi System. R'ith the existing slope gradients, These soils will have a slight to moderate potential for erosion when exposed. Therefore, the site is not an erosion hazard area as defined by the YMC. Regardless, erosion protection measures as required by the City of Yelm will aced to be in place prior to starling grading activities on the site. This would include perimeter silt fencing to contain erosion on-site and cover measures to prevent or reduce soil erosion during and following construction. 4.3 l,andslidc Hazard Section 14.OS.I30 of the YMC defines Landslide hazard areas as areas potentially subject to landslides based on a combination of geologic, topographic, and hydrologic factors. They include areas susceptible because of any combination of bedrock, soil, slope (gradienQ, slope aspect, stricture, hydrology, or other factors. Based on the soil and topographic conditions of the site, no poriiats of the sire are susceptible to risk of mess movement and; Therefore, no portions of the site would be considered a landside hazard area. Page No. 3 May 5, 2010 Project No. T-6437 5.0 DISCUSSION AND RECO111ME1yDATIONS 5.1 Gcueral Based on our study, there are no geo(echnical considerations that would preclude development of the site, as currently planned. however, as described earlier, our exploration indicates the upper 2 to 2 Y: feet of soil is fill material that contains a considerable amount of organic soil. In our opinion, this upper soil horizon will not be suitable for support of building foundations or immediate support of floor slabs' and pavements. l'he buildings can be supported on conventional spread footings bearing on competent uative soils observed below this upper 2 to 2.5 feet of organic fill material or on stntctural fill placed and compacted above competent mineral native soils. Pavement and floor slabs can be similarly supported. The following sections provide detailed recanuuendatious regarding the preceding issues and other geotechnical design considerations, These recommendations should be incor)~orated into the tinal design drawings and consu'uction specifications. 5.2 Site Prenaratiou and Gradiue Ta prepare the site for construction, al( vegetation, organic surface soils, and other deleterious material should be stripped and removed from the building and paved areas, Surface stripping depths of about 2 to 2.5 feet should be expected to remove the organic surface fill. The organic fill material will not be suitable for use as structural fill, but may be used far limited depdts in nonstructural areas. Once clearing and stripping operations are complete, cut and fill operations can be initiated to establish desired building grades, Prior to placing fill, all exposed bearing surfaces should be observed by a representative of Terra Associates to verify sail conditions are as expected and suitable for support of new fill or building elements. Our representative may request a proofroll using hea~ry rubber-tired cyuipment to determine if any isolated soft and yielding areas are present. If excessively yielding areas are abserved, and they catmot be stabilized in place by compaction. the affected soils should be excavated and removed to firm bearing and grade restored with new structural fi(I. If the depth of excavation to remove unstable soils is excessive, the use of geolextile fabrics, such as Mirafi 500X, or an equivalent fabric, can be used in conjunction with clean granular structural fill. Our experience has shown that, in general, a minimum of 1S inches of a clean, granular structural fill place and compacted over the geotextile fabric should establish a stable bearing surface. The ability to use native soil from site excavations as structural fill will depend on its moisture content and the prevailing weather conditions at the time of construction. The fines content of the gramdar native outwash observe below the 1111 horizon typically ranges between rive to 12 percent, Gravel outwash with a tines content of less than five percent was observed at 'lest Pits TP-4 and TP-7 below a depth of five feet. In our opinion, these uative soils will be suitable far use ns structural fill and french backGll. However, the fines content of most of ouhvash will make the soil slightly to moderately moisture sensitive and close moisture camol will be required to facilitate proper compaction. During dq~ weather conditions, the contractor should be prepared [o add water in order to facilitate compaction. During wet weather, the fines content of the autwash may cause the sail to become unstable in a till conditirnt and unsuitable for use as fill. In this case, the contractor should be prepared to dry the soil back io suitable moisture content by aeration or use an additive such as cement kiln dust, Portland cement, or lime Ia stabilize the moisture. if an additive is used, the pH of the soil will be elevated and additional measures for monitoring pH of stonnwater runoff along with mitigation measures will need to be included in the projects Stone Water Pollution Prevention Program (SW PPP). Page No. 4 May 5, 2010 Project No. T'-6437 If importing soil for grading or backtilling during wet weather conditions becomes uecessaiy, we recommend importing a granular soil that meets the following grading requirements: ~._. ~,~ U 4s;~trve $t?e .,.,z .w,h_ . .s ...,w~, ~,,.Pcrcent Pacsin~ , ~. n,.w., No. 4 75 maximum No. 200 5 maximum"` Based on the 3/4-inch fraction. Prier to use, Ten'a Associates, htc. should examine and test all materials impotled to the site for use as sultetm~al fill. Stivctural fill should be placed in uniform loose layers not exceeding l2 inches and crnupacted to a minimum of 95 percent of the soil's maximum dry density, as determined by American Society for Testing and Materials (ASTM) Test Designation D-69S (Standard Proctor). The moisture content of the soil at the time of compaction should be within two percent of its optiunun, as determined by this AST'M standard. In nonsuvewral areas, the degree of compaction can be reduced to 90 percent. 5.3 Excavations All excavations al the site associated with confined spaces, such as utility wenches, must be completed itt accordance with focal, slate, and federal requirements. Based on regulations outlined in the Rrashington Industrial Safety and Health Act (\VISHA), the glacial sediments observed would be classified as Type C soils. Accordingly, temporary excavations in Type C soils should have their slopes laid back at an inclination of 1.5:1 (Hm'i-r-onlal:Vertical) or flatter, from the toe to the crest of the slope. All exposed slope faces should be covered with a durable reinforced plastic membrane during conshuction to present slope raveling and noting during periods of precipitation. For utility trenches, a properly designed and installed shoring wench box can be used to suppon the excavation sidewalk. "Phe above information is provided solely for the benefit of the owner and other design consultants, and should not be cmtsuzted to imply that'perrt Associates, free. assumes responsibility for job site sa('cty. It is understood that job site safety is the sole responsibility of the project contractor. 5.4 houndation Supuart The buildings can be supported cn conventional spread footing foundations bearing on competent native soils or on swctural fills placed above competent native soils. Foundation suhgrade should be prepared as' recommended in Section S:L of This report, Perimeter foundatiots exposed to the weather should bear a minimwn depth of 1.5 feet below final exterior grades for frost protection. Interior foundations can be constructed at any convenient depth below the floor slab. Foundations can be dimensioned for a net allowable bearing capaciq of• 2,500 pounds per syuare foot (psf), Por short-Ietm toads, such as wind and seismic, none-third increase in this allowable capacity can be used. \Vith sultctural loading as anticipated and Ibis bearing stress applied, estimated total settlentenis are less than one-inch. Page No. 5 play 5, 20]0 Project No. "1"-G437 Par designing foundations to resist lateral Toads, a base friction caefticiemt of 0.35 can be used. Passive eai7h pressures acting an the side of the Footing and buried portion of the foundatirni seem wall can also be considered. \Ve recanunend calculating this lateral resistance using an equivalent fluid weight of 300 pct. N%e reconuncnd not including the upper (2 inches of sail in this computation because they can be affected by weather or disturbed by future grading activity. This value assumes the foundation will be constivcled neat against competent native soil or back511ed with shvetural fill as described in Section 5.2 of this report. The values recommended include a safety factor of L5. SS floor Slah-on-Grade Slab-on-grade floor cmt be supported an subgrade prepared as recommended in Section 5.2 of this repar7. It is typically recommended to place afour-inch thick capillary break layer composed of clean, coarse sand or Cme gravel that has less than three percent passing the No. 200 sieve iuuuediately below the slab. 'T'his m<nerial reduces the patential for upward capillary movement of water throueh the underlying soil and subsequent welling of the Iloor slab. However, in om• opinion, if clean native outwash that meets the criteria described above is exposed at the floor subgrade elevation or used as structural fill to establish the floor grade, it would not be necessary to import material for placement as capillary break below the slabs. A representative of Tetra Associates shauld observe the subgrade to verify the suitability of the native autwash to serve as the capillary break layer at the lime of consuvction. 'T'he capillary break layer will not prevent moisture intnrsian through the slab caused by wafer vapor transmission, Nhcre moisture by vapor transmission is undesirable, such as covered flom• areas, a common practice is to place a durable plastic membrane on the capillary break layer and then cover the membrane with a layer of clean sand or fine gravel to protect it from damage during canstnrction, and to aid in uniform curing of the concrete slab. It should be noted that if the sand or gravel layer overlying the membrane is saturated prim• to pouring the slab, it will not be effective in assisting uniform cwin, of the slab and can actually serve as a water supply for moisture bleeding through the slab, potentially affecting floor coverings. 'T'herefore, in our opinion, covering the membrane with a layer of sand or gravel should be avoided if floor slab consnvction occws during the wet winter months and the layer cannot be effectively drained. GVe recommend floor designers and contractors refer to the 2003 American Concrete lnstihue (AST) Manual of Concrete Ptnctice, Pan 2, 302.]R-96, for further information regarding vapor barrier installation below slab-on-grade floors. S•6 Stormrvatcr Imtiltration Feasibility ',Ve expect that infiltration Facilities will be considered for stonnwater management. T'he recessional outwash sands and gravels we observed at the site would be a suitable receptor formation for infiltration discharge. Depending ou the location of the infilu•ation facilities, it may he necessary to excavate five feet or tuore below cunent site grade. to reach the suitable outwash layer. To determine the loner teen design infiltration rate, we used Llethod 2 as outlined in Section 3,3.6, Volume Ill of the Geology's S'tornnrnler Moncrgemenr ,1~lanurrl,(m• i14r.vcrn R'n.cGiuglun. This method conclates the long-Term infiltration rate with gradation testing of the soils in accordance with ASTbI "Pest Desiguatian D-422. Gradation cun~es' from laboratory testing an the soils are attached in Appendix A. Based on the resuhs of-The testing and on Figure 3.6 in Geology's Srornnrrner Muuagcnreru cflunurrl far H'ertcrr7 H'~rshingron, we recommend using a long- term design infiltration rate of two inches per hour. Page No. G A4ay 5, 2010 Project No.'f-6437 The permeability of the native outwash soils will be significantly impacted by the ininrsion of soil fines (silt- and clay-sized particles). Even a relatively minor amount of soil fines can reduce the penueability of the fomration by a factor of ten. The greatest exposure to soil foes contamination will occur during mass grading and construction. Therefore, we recommend that the Temporary Erosion and Sedimentation Control (TGSC) plans route construction stormwater to a location other than the pennauent infiltration site. If this is not possible, the 'I ESC pond bottom elevation should Ue kept hv0 feet above the final infltratiou elevation with final grade established after site areas have been subs(antially staUilized. We should review stomtu~ater management plans when they become availaUle to verify suitability of soils in the plarmed locations and to provide supplemental discussion and reconunendatious, if treaded. 5.7 Ih•ainasc Sruface Final exterior grades should promote f ee and positive drainage nway fran the site at all times. 1Vater must not be allowed to pond or collect adjacent to foundations or within the inunediate building areas. We reconuncnd providing a gradient of at least three percent for a minimum distance of ten feet from the building perimeters. If this gradient cannot be provided, surface water should be collected adjacent to the shtictures and disposed to appropriate storm t<lcilities. Subsw face Cauideriug the well-drained nature of the native site soils, provided the finish floor grade is at or above the adjacent exterior grade and positive drainage away from the stnreUn'e is maintained, in our opinion, perimeter foundation drains would not he required. If these conditions are not met, footing drains should be placed at the perimeter of each structure. The tooting drains should consist of a ['our-inch diameter perforated PVC pipe that is enveloped in clean washed %-inch drainage aggregate. The aggregate envelope should extend a minimum of six inches above and to the sides of the pipe and three inches below the pipe invert. The drain pipe can be placed at a uniform grade wish an invert equivalent In the Uottom of the adjacent fooling and tied to discharge into the development storm system. Reverse gradient or Ucllies in the pipe must Ue avoided. Surface water discharge elements such as downspouts or yard drains should not Ue lied directly or indirectly into the footing drains. 5.8 Lltilities Utility pipes should be bedded and Uackfilled in accordance wish American Public Works Association (Af'WA) or City of Yelm specifications. As a minimum, trench backfll should Ue placed and compacted as structural fll, as described in Section 5.2 of•this report During wet weather conditions, it may Ue necessary to import suitable acct weather soil for use as backfill. 5.9 Pavement Pavement subgrades should be prepared as described in the Section 5.2 of this report. Regardless of the degree of relative compaction achieved, the suUgrade must be litm and relatively unyielding before paving. The subgrade should be proofrolled with heavy construction equipment !o verify this condition. Page No. 7 May 5, 2010 Project No. 'C-G437 The pavemem design section is dependent upon the supporting capability of the subgrade soils and the traffic conditions to which it will be subjected. For arsitc access and parking, with traffic consisting mainly of light passenger vehicles with only occasional heavy traffic, and with a stable subgrade prepared es recommended, we recommend the following pavement sections: • 'fwo inches of hot mix asphalt (HMA) over four inches of crushed rock base {Cl~) • "Cwo inches ofHMA over three inches ofasphalt-treated base (A'I'I3) The paving materials used should conform to the R'ashington State Department of 'll'anspor(ation (WSDOT) specifications for %z-inch class HMA, ATI3, and CRB. Long-term pavemem performance will depend mt surface drainage. A poorly-drained pavement section will be subject to premature failure as a result of surface water infiltrating into the subgrade soils and reducing their supporting capability. I'or optimum pavement performance, we rcconuuend surface drainage gradients of at least two percent. Some degree of longitudinal and transverse cracking of the paverneut surface shotdd be expected over tone. Regular maintenance should be planned to seal cracks when they occur. 6.0 ADDT'i'IONAL SIiRVICIiS Terra Associates, htc. should review the final design drawings and specifications in order to verify that eanh~aork and fowtdation recommendations have been properly interpreted and implemented in project design. We should also provide geoteclmical service during catshnction to observe compliance with our design concepts, specifications, and recommendations. This will allow for design changes if subsurface conditions differ from those anticipated prior to the Stan of construction. 7.0 LI\1ITATIONS We prepared this report in accordance with generally accepted geotechnical engineering practices. No other warranty, expressed or implied, is made, This repot is the copyrighted property of Tema Associates, [rte. and is intended 1'or specific application to the Salmon Run Apartments project. This report is for the exclusive use of Timber River Development and its authorized representatives. The analyses and recommendations present in this report are based on data obtained from the test pits and borings done nn site. Variations in soil conditions can occur, the nature and extent of which may not become evident anti( constnuction. If variations appear evident, "Cerra Associates, htc. should be requested to reevaluate the recommendations in this report prior to proceeding with consdziction. Page No. S gyp. .. ,.r c. ,,. ~ a ~a U~ o ''hiv. ~ ul I ~° oi, ~ ~ ~;°Crc'ek4°~~ O~ c~ ~ vOT o'S~ 01 ~s G9;~ 100tf-~ Way &E' ~°'~a sr,~, Far St€ ens n,~ F ,, Fiatt~entflry `'~iF . `~ ScfEoa a g` ~~, .aa 5U7 ~`'~ ~ ~a s a y'Ps~s~ a ~, r~ S~, Old Ye!m•Me Kenna F 1.!$ 143rd Ave 103rd Ave SE. Cy "., m ~ - X (n (~` m Qy~.rr G AI m SS`f Yp CI g.~ th Aire SE ~ ~ m ~ Rd NE . ~• 507 't d ~' ~ ~ra 5t 5E }, ~ -Y 3E a ~ ~ ri ~ r~ ~ ~ SITS ~ "' 9afew,~y ~ ~ , ~' /V to ~'! m _ ~p sfi ~ ; , 107th Si SE I ~ wKtantl ~St &~ m x ~ i a 1~ 6 ~ I m m ,,` A aiay'~1~d m ~ m 108th Ave SE ~ ~'••~ ~ o h .... •,,..~.... t Cfark Rb SE ;~ REFERENCE: GOGGLE MAPS, W4VW.GOOGLE.COM, ACCESSED 4-27-2010 NOT TO SCALE Terra VICINITY MAP SALMON RUN APARTMENTS Associates ~t1C. YELM, WASHINGTON • Consultants in Geotechnical ~ngineedng Geology and Environmental Earth SGences Proj. No.T-6437 Date MAY 2010 Figure 1 s a~n _ ., w oQ= -~ la-~ ~' ~ v ~ JZQ ~ a} \ is ~ ~ k_ a~ o O~> o ~~-~i ~ d ~~ ~ •~ -~ U- ~ ~ ~ ~ , ~ C~i ~ vi9 w m t9&oe 1 ~ N~ 1.., I ~i ~) I // O ~ ~ :. ~~ ~3 l I ~ -- \~ nc®aoau ®~ - ~$- Q-~-Q ~/ ~_ ~ ~~~ - -- ~;~ T~~ o ~~ 0 I V I L ~ off _~ W W _ _~_T ~; :: ~~ J ~ --- ~.~ ~ ~~# a ~ G~ ~I_ . ~ oLL I ~ ~~ ~~~ w ,,. --~~- t- of ~=m~ w 0 --- ~~, two= m '~ _s~n w ~ ~==o '; - of m~o~ m ' o ~'.' _ l7 ma>~'n ._ T~ O' zGZO .. o ~N~U W d ' l~~ wOZO Z ~ + ~ f ~% ! r,nwz W s t n.~ nzrc~ ¢ n _._ .__--... o ~orcn w m z a Arr~Nt~tx A FIP:LA EXPi~ORA7YON ANll LA130RAT'OR1' TES"PING Salmon Run Apartments Yclm, «'ashingtou On April 27, 2010, we completed our site exploration by observing, soil conditions ai 7 tell pits. 'I'hc test pits were excavated urine a backltoe to a maxiuuuu depth of ten feel below existing site grades. Test pit locations were determined in the field by measurements from existing site features. "1'he approximate location of the test pits are shown at the attached Cxploration Location flan, Figure 2, `l'est Pit Logs are attached as Figures A-2 tlvaigh A-S. A geoteclmical engineer from our office conducted the field exploration. Our representative classified the soil conditions encountered, maintained a log of each test pit, oblaincd representative soil samples, and recorded water levels observed during excavation, All soil samples were visually classified in accordance with the Unified Soil Classification System (USCS) described on Figure A-1, Representative soil samples obtained from the ter( pits were placed in closed contahters and taken to our laboratory for further examination and tesfiue. The moisture content of each sample was measured and is repnrtui on the individual Test Pit Logs, Grain size analyses were perfomred on selected samples, The rzsuhs of the grain size analyses are shown on Figures A-9 and A-!0. Pt'gject No. T-6437 MAJOR DIVISIONS ~ LETTER I TYPICAL DESCRIPTION SYMBOL Clean G~/ GRAVELS Gravels _ _ J m ` (less than GP p m ~ ! More Ihan 5% tines) -- ~ ~ ='N 50% of coarse t i GM ~ > raction s Gravels W ~ °~ larger than No. with fines _ z ~ E `~ 4 sieve G C Q ~ o Q o ~_ i - - - _ _ _ __ Cleari 5W SANDS Sends W c z L (less than I SP ~ c u More than 5% flees) m w 50% of coarse ...._ __._--- p o fraction is $M U ~ smaller than Sands ~ No. 4 sieve i with fines ~ I SC _... ..- -- .._ -- -_T ._...- -- ~ ' ML Well-graded gravels, gravel-sand mixtures, little or no fines. Poorly-graded gravels, gravel-sand mixtures, little or no fines Silty gravels, gravel-sand-silt mixtures, non plastic fines. Clayey gravels, gravel:•sand-clay mixtures, plastic fines. Well-graded sands, gravelly sands, little or no fines, Poorly-graded sands: or gravelly sands, tittle or no fines. Silty sands, sand sdt mixtures, non-plastic fines. Clayey sands, sand-clay mixtures plastic fines. Inorganic sills, rook flour, clayey silts with slight ~ ~ ~ co ! SILTS AND CLAYS ` __ Plasticity. _. _- ._ _ -__ O ~ N ~ ~ CL Inorganic clays of low to medium plasticity, (lean clay). N E d ~ Liquid limit is less than 50% - -- - - -- - - - - -- - ~ o Z N ~ OL Organic silts and organic clays of low plasticity. I e~ ~ ~ -..._._.._...._ ~ M1-1 Inorganic sifts, elastic. ~ C7 ~ ~-~' - SILTS AND CLAYS _ _ _ .. -- _ _ ~ ~ ~ ('H Inorganic clays of high plasticity, fat Clays W Z o N Liquid limit is greater than 50% -- __.- _ _-____ _. tL ~ OH Organic clays of high plasticity. HIGHLY ORGANIC SOILS ~ PT Peat, DEFINITION OF TERMS AND SYMBOLS <n Standard Penetration ff 2" OUTSIDE DIAMETER SPLIT w Density Resistance_in Blows/Foot _L SPOON SAMPLER ~ Very loo se 0-4 T 2.4" INSIDE DIAMETER RING SAMPLER Loose 4-10 OR SHELBY TUBE SAMPLER ~ Medium dense 10-30 = Dense 30-50 '~ WATER LEVEL DATE) ( o ~ Very dense >50 Tr 70RVANE READINGS, tsf ^~ Standard penetration Pp PENETROMETER READING, tsf Consisted Resistance in Blows/Foot pp DRY DENSITY, pounds per cubic foot w ~ Very soft 0-2 LL LIQUID LIMIT, percent w Soft 2-4 z Medium s tiff 4-8 PI PLASTIC INDEX O e 1 N STANDARD PENETRATION, blows per foot V ry stiff 16 32 Hard >32 Terra UNIFI ED SOIL CLASSIFICATION SYSTEM `~~~~ ~~~~•:_-~ ~ ` IIIC Associates SALMON RUN APARTMENTS ` GTON • / , . (ELM, WASHIN J Consultants in Geolechnical Engineering Geology and Environmental Earth Sciences Proj. No. T-6437 Date MAY 2010 Figure A-1 1 LOG OF TEST PiT NO . FIGURE q•2 PROJECT NAME: RRlmon Run ariments PROJ. NO: T-,49~ LOGGED BY: CS LOCATION: Yelm WRShingion SURFACE CONDS: Tall Gress/Small Trees APPROX. ELEV: DATE LOGGED: aril 27, 7010 DEPTH TO GROUNDWATER; NIA DEPTH 70 CAVING; ~ F -gl N O w -~ ESCRIPTION CONSISTENCY/ '~ Z EMARKS d ~ RELATIVE DENSITY 3 W w 4 Y O in U O a FILL?: dark brown sand with silt, fine grainetl, moist, roots, extensive organics. A4edium Dense 16 1 . Brown silty SAND, fine grained, moist roots. (SM) __________________________________ Medium Dense ___________ 1 11 . 5 Bro~.vn SAND with sill and groveh line to coarse grained. Medium Dense moist (o wet. (SP-Sh1) 9.0 Test pit terminated at approximale{y 8 feet. No groundwater seepage observed. Minor caving observed below 3 feel. 10 15 Terra ; NOTE: This SUbsudace information Pertains only to this lest Gl :c:zlion and shau!d ,_. L- ;~.`` /aSSOCIa(QSr ~fTC. not be interpretetl as being intli:a6ve of other (cations of the sqe. ConsullaNS in Geolechnlcal Englneennp Geolcgy antl Enwronnrenlal EaM Sciences 2 LOG OF TEST PIT NO . FIGURER-3 PROJECT NAME: Salmon Run Anarimanls PROJ. N0: T-6437 LOGGED SV: ~_ LOCATION: Yalm Washingl2n SURFACE CONDS: Tall Grace/Small Trees APPROX. ELEV: DATE LOGGED; ADril 27 2010 DEPTH TO GROUNDWATER: N(A DEPTH 70 CAVING: 7 Feet LL .-, ~ H .J .. w a DESCRIPTION CONSISTENCYI a n. REMARKS RELATIVE DENSITY H a 3 w V o r n 0 a moist roots flll?: bla k silt sand line rained 26 9 , y , , , c g . extensive organics. Medium Dense 10 8 . 5 Brown SAND with silt, fine to coarse grained, moist Io Medium Dense wet, varying amounts of gravel. (SP-SM) 21 2 . t0 Test pit Terminated al approximately 10 feel. No groundvrater seepage observed. Moderate caving observed below 2 feet. 15 ~~.~ Terra . _r NOTE: This subsurface Ulfcr/na6A0 pertains only (o this test pit !ccation and should . . ~s~ Associates, it1C. not 6c interpreted as being indicative of olF.er Io:aGOn^, at the sale. CcnsullanLS n Geolechni~l Engineering GacIC:JY and Environmental Eanh Sciences 3 LOG OF TEST PIT NO . FIGURE A-4 PROJECT NAME: Salmon Run Apnrtmen(s PROJ. NO: T-04'7 LOGGED BY: CS LOCATION: YPIm. WRShinulon SURFACE CONDS: Tall Grass/Small j[ ~;- APPROX. ELEV: DATE LOGGED: 8p1iI ~7 2010 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: 4 Feet LL !- =~ x w ~ DESCRIPTION CONSISTENCYI z REMARKS RELATIVE DENSITY 3 W a ~ U Q N O a FILL?: black silty sand, fine grained, moist, roots, 16 8 extensive organics. Medium Dense , __________________________________ ___________ 12 5 . Brown SAND with silt fine to coarse grained, moist, roots. Medium Dense (SP-SM) 5 Brown SAND with sill and graveh fine to coarse grained. moist, occasional cobble. (SP-SM) Medium Dense 6 4 . Test pit terminated at approximately 8 feet. No groundwater seepage observed. Minor caving observed below 4 feet. 10 15 Terra ,y: NOTE: This subsur(ace in(crmalion perlams cnly to this lest pi(locacon acd should - ~ ,;,I. -;.- ASSOCIateSr ~nC. rot to inlerp:eletl as oeing indicaUvc c1 other loalions al the Bile. Ccnsullanls in Geoleahnial Engineering Geology and Ernironmenlal Ea@i Sciences LOG OF TEST PIT NO. 4 FIGURE A~S PROJECT NAME: Salmon Run ADartmenls PROJ. N0: Zfi437 LOGGED BY: CS LOCATION: Velm. Washington SURFACE CONOS: Tall GrasslSmall TrESi- APPROX. ELEV: DATE LOGGED: _April 27 2010 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: 2 F .e-l LL H h 0 Z _ Z x w ~ DESCRIPTION CONSISTENCY! RELATIVE DENSITY ^ 3 w W EMARK a ~ W O Q h Y U O a 17 3 f . ine to coarse FILL?: black sand with sill and gravel, grained, moist, roofs, extensive organics. __________________________________ Medium Dense ___________ 5 3 . Brown GRAVEL with sand and cobbles, coarse grained, 5 moist, occasional boulder. (GP) Medium Dense Test pit terminated al approximately 8 feet. No grountlwater seepage observed. Extensive caving observed below 2 feel. 10 75 .3~ Terra av s,E?::w NOTE: This subsurface inlormaGOn pertains only to Uis test Gil IaaGOn and should - Nah^ AS SOCI ate S, )r1C. not be inlerpretetl as Demg indi:ative of other IocaCens al the Bile. Coasullanls .n GeolechNwl Ggineedng Geology and Envircnn;enlal Earih Sciences LOG OF TEST PIT NO 5 . FIGURER-6 PROJECT NAME: Salmon Run gpartm .nts PROJ. NO: T-8437 LOGGED BY: CS LOCATION: Yelm Wagj7~glon SURFACE CONDS: Tall Grass/Small Trees APPROX. ELEV: DATE LOGGED: ADril 27. 7010 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: u: F d t s m a DESCRIPTION CONSISTENCY/ RELATIVE DENSITY °= m ~ REMARNS W ¢ S' y A N U O 6 FILL?; black sand with silt and gravel, fine to coarse grained, moist roots, extensive organics. i D 18 9 um ense Med . __________________________________ ___________ 5 4 B SANp i h d fi t i d i t Mediwn Dense . o coarse gra rown l, ne ne , mo s to w t s wet, some sill. some gravel. ISP-SM) 5 8 5 . Test pit terminated at approximately 8 feet. No groundwater seepage observetl. Minor caving observed below 2 feet. 10 15 Terra ~ ~ ;, NOTE' This su5su~7ace mfo~mahon Penams cnly to Nls lest piHt=aGUn and shculd , ~ Associates, IRC. not be inlerpreletl as ne rg md:calive of ogler Ieca~ons at the 51R. Consulanif in GeaiechrcG21 Engireenrg Geology and Enoiroamenfal Eann Sciences LOG OF TEST PIT NO 6 . FIGURER-7 PROJECT NAME: Salmon Run Anariments PROJ, NO: T-8437 LOGGED BY: ('S LOCATION: , Yelm Washington SURFACE CONDS: T~Grase APPROX. ELEV; DATE LOGGED: Anvil 27 2010 DEPTH TO GROUNDWATER: N/A DEPTH TO CAVING: 2 Fa~_ w ~ ~ d z x w ~ DESCRIPTION CONSISTENCY/ REMARKS ~ RELATIVE DENSITY W a ~ ~ ~ O a FILL?: black sand with silt and gravel, line to coarse grained, moist, roofs, extensive organics. m Dense M di 13 1 e u . __________________________________ Brown SAND with sill fine to coarse grained, moist Io ___________ Mediun Dense wet, some gravel, occasional cobble. (SP-SM) 5 __________________________________ ___________ 7.4 Gray SAND wish sill, line to warse grainetl, moist. (SP- SM) Medium Dense Test pit lerminated at approximately 8 feel. No groundwater seepage observed. Moderate caving observed below 2 feel. 1D 15 -.. Terra ~~" r NOTE: This subsurface inlcrmation penain5 only Io Ihis lest pif Iccation and should ` Associates, Inc. ~` ' s' rr not be mterpreled as being mdicalrve of other local ens al the ste. Consultants in Geolechrecal Engiceering Geology and Envircnmenlel Eanh Sciences LOG OF TEST PIT NO 7 . FIGUREA~B PROJECT NAME; Salmon Rtm Apartments PROJ. NO: T•6437 LOGGED BY: ~S LOCATION: Y .I~ m VJeahinq(on SURFACE CONDS: j,~l CiRgdSmall Trees APPROX. ELEV: DATE LOGGED: April 27 2010 DEPTH TO GROUNDWATER: N(({ DEPTH TO CAVING: 2„~ Feet LL _ ]~ f' Z Z LL' x >_ m -, a DESCRIPTION CONSISTENCYI RELATIVE DENSITY m a r- REMARKS W C ~' Y ^ N U O a FILL7: black sand with sill and gravel. fine to coarse 16 7 grained, moist, roots, extensive organics. M di D . ense e um Brown silty SAND, fine grained, wet. (SM) Medium Pense 7 19. 5 __________________________________ ___________ Brown GRAVEL with sand, fine to coarse grained, moist D 6 8 to wet, cobbles, occasional boulder. (GP) ense . Test pit terminated al approximately 8.5 feet. No groundwater seepage observed. Moderate raving observed below 2.5 feel. 10 15 ,.~ Terra s~.t ,. NOTE: This subsurface information pertains oNyto ibis lest plr teca6en and should ~~ ,-=~,`rr".~. ASSOCIat@Sr (ITC. not Le mlerp;elM as being intlitalive o1 oNer locations at It>e site ConsullaNS m.Gmtechnical Enniceencg Geology and Environmental Fanh Sciences Particle Size Distribution Report IQD 90 80 7e LL W Z ry°Gravel - %Sand `YeF(nes %+3„ Coarse Fine Coarso! Medium Fine _ _ Silt __ Clay_ ~ o ____ __ O.U 11.3 62.4 10.7 14.7 i 3.4 _ _ 4 ___ La 0 0.0 _ D.0 0.0 _ 0 2 ~ 57.6 ' 35.2 7.0 -- X Lt. PL -D85_._ D Osp d D3 D, ~~-_ C o - - I7.4217 I1.031R 9.17RR 5.8352 - L7G57 [67313 3.73 - 1>.OS - ^ _ ~ 0,7014 -- 0.5243. - 0.44R1 0.3539 0.2430 } 0'1570 152 3.34 Material Description -_ - USCS - AASHTO o Poorly graded GRAVEL a-itll sand ~~- GP I a Poorly graded SAND a~ilh silt Sf S~ Project No. T-0437 Client: Timber River Development Remarks: (Project: Selmon Run Apm vnem. OTcsted on 4-29-10 ~ ~ .iTcsied on 4-29-10 f v Location: Tcsl Pit TP-4 Depth: -4 feel Sample Number: 2 Location: Tcsl Pit TP-5 Depth: -7.5 tics Sample Number: 3 ! Terra Associates, Inc. Figure r~-9 Tested By: CS _ %+3" ~_ °[°Gravei ~ %Sand _. %Fines _Coarse Fme Coarser Medturn Fine Srlt .~ 0.0 0.0 07 __ q 7 I SO I _ t3.6 4.9 0.0 ~ 0.0 01 03 79 ~ 73.3 ~ -- 15.4 _ o O.R236 .__0.6465 ~ 0,5920 0.4903 _ 0.3662 0.2767 1.34 2 34 0 0.3843 ~ 0.2997 ^~ 0.2699 D.I937 -- - .___~_ Material DeSCription USCS ~ AASHTO c Poorly ~raAed SAND wish silt -_ ~--- SP-SPt I o SiIq~SANp SA1 Project No. 'i'-6437 Client: Timber Ri~~er 1)cvclopntem Remarks: Project' Salmon Run Apartments oTe,ted on 4-29-10 iaT'esred on 4-29-10 o Location: list Yii TP-(, Depth: -5 lief Sample Number: 2 o Location: Test Pit TP-7 depth: -4 feet Sample Number: 2 Terra Associates, Inc. Kirkland WA _._a Figure A-l0 Tested By: ~COFFMAN NGINEERS Sahnai Run Apartments STRP System Report STEP SYSTEM PLAN ATTACHMENT"C" "°"" ~"°' "" . ~ ~ ~~ >.~ ( " S11NlI 9NIhl"1 Ob E vu-wv wirunm vd nvx'•w slrosrvn'+ws+~w *+oi x - ~ ~ S1N3W1L'HdV NUJ NOWIVS $ g 9 Q m io e ~ ~ 4,~ ~ ~ = ~ pp NdW~dO~I M~5 < ~ ~' g g ~ ,,,,,,. ~, ~ NHId ?J3 ra ~ ~ g g 0 Z Q 3 O U z O IXi l N C u S ~y~d~ ~2 e~~6~~ ~ ~ 2~ R v~ 4" 88888 n ~ ~`~u ~35~~'s3g ~9~~ ~$ N ~~ ~ ~ m g~~~ %r~~~ ~S~ ~"kc~k~~~ `~' ~} & _''a ~ s i y fi '35 i5g ~1~~>~~ ~a~~E~. "a ~U~a~3~`s~~~ ~~~~~~~~ z ~~q~~ ~ o.®.o o•:Y:9 w I ~~ k3 8 :~~~` ~' A j€ F ro g ~ i r s b ~ 3 g a~ - p ~~ ~ 6 ~ ~~ ~ ~ ~ ~~ ~~ ,~ 8d~¢ ~~m %~ ~ ~ A~ 3P~ @ ~~ ~ ~a ~~ ~¢ ~ ~ ~ ~ ~o ~s ~~ g ~~ ti ~~~~ ~~~'~E e ~a ~~t~yg~ „~" ~ h h 3. &6 ' ~ E' ~ ~ d 8. 33 m; hr ~~ ~~ ~~Gq Keo a~ & k~ ~ Ux 3 y n n • n n n m m ~COFFMAN N G I N E E R S Sa_1_m_on Run Apartments STLP System Report STEP TANKSIZING & PUMP CALCULATIONS ATTACHMENT "D" PROJECT: SALMON RUN APARTMENTS FILE: 10247 Date: 7/15/10 STEP TANK SIZING CALCULATIONS BUILDING A 2 x 4 BR UNITS 4 x 3 BR UNITS 2 x 2 BR UNITS 2 x 1 BR UNITS 26 BEDROOMS STORAGE VOLUME REQUIRED COFFMAN ENGINEERS, INC. 10 N. POST ST., SUITE 500 SPOKANE, WA 99201 # PERSONS = 52 Q= 26 BD x 2 PERSONS/BR x 65 GAVPERSON/DAY Q= 3,380 GALLONS DETENTION VOLUME REQUIRED V= 1.5Q V= 1.5 x 3,380 GALLONS V= 5,070 GALLONS TOTAL TANK VOLUME REQUIRED VOLUME = 3,380+5,070= 8,450 GALLONS DETENTION VOLUME PROVIDED USE (1) 6,000 GALLON TANK AND (1) 4,000 GALLON TANK 10,000 GALLONS PROVIDED FOR BUILDING A 10,000 GALLONS PROVIDED > 8,450 GALLONS REQUIRED BUILDING B 4 x 3 BR UNITS 4 x 2 BR UNITS 20 BEDROOMS # PERSONS = 40 STORAGE VOLUME REQUIRED Q= 20 BD x 2 PERSONS/BR x 65 GAUPERSON/DAY Q= 2,600 GALLONS DETENTION VOLUME REQUIRED V= 1.5Q 1 OF 4 PROJECT: SALMON RUN APARTMENTS FILE: 10247 Date: 7/15/10 STEP TANK SIZING CALCULATIONS V= 1.5 x 2,600 GALLONS V= 3,900 GALLONS TOTAL TANK VOLUME REQUIRED VOLUME = 2,600+3,900= 6,500 GALLONS BUILDING C 2 x 3 BR UNITS 4 x 1 BR UNITS 10 BEDROOMS COFFMAN ENGINEERS, INC. 10 N. POST ST., SUITE 500 SPOKANE, WA 99201 # PERSONS = 20 STORAGE VOLUME REQUIRED Q= 10 BD x 2 PERSONS/BR x 65 GAUPERSON/DAY Q= 1,300 GALLONS DETENTION VOLUME REQUIRED V= 1.5Q V= 1.5 x 1,300 GALLONS V= 1,950 GALLONS TOTAL TANK VOLUME REQUIRED VOLUME= 1,300+1,950= 3,250 GALLONS DETENTION VOLUME PROVIDED FOR BUILDINGS B & C USE (1) 6,000 GALLON TANK AND (1) 4,000 GALLON TANK 10,000 GALLONS PROVIDED FOR BUILDINGS B & C 10,000 GALLONS PROVIDED > 9,750 GALLONS REQUIRED BUILDING D 4 x 3 BR UNITS 4 x 2 BR UNITS 20 BEDROOMS # PERSONS = STORAGE VOLUME REQUIRED Q= 20 BD x 2 PERSONS/BR x 65 GAUPERSON/DAY Q= 2,600 GALLONS 40 20F4 PROJECT: SALMON RUN APARTMENTS FILE: 10247 Date: 7/15/10 STEP TANK SIZING CALCULATIONS DETENTION VOLUME REQUIRED V= 1.5Q V= 1.5 x 2,600 GALLONS V= 3,900 GALLONS TOTAL TANK VOLUME REQUIRED VOLUME = 2,600+3,900= 6,500 GALLONS BUILDING E 4 x 3 BR UNITS 4 x 2 BR UNITS 20 BEDROOMS STORAGE VOLUME REQUIRED Q= 20 BD x 2 PERSONS/BR x 65 GAUPERSON/DAY Q= 2,600 GALLONS DETENTION VOLUME REQUIRED V= 1.5Q V= 1.5 x 2,600 GALLONS V= 3,900 GALLONS TOTAL TANK VOLUME REQUIRED VOLUME= 2,600+3,900= 6,500 GALLONS DETENTION VOLUME PROVIDED FOR BUILDINGS D & E USE (2) 6,000 GALLON TANKS AND (1) 4,000 GALLON TANK 16,000 GALLONS PROVIDED FOR BUILDING D & E 16,000 GALLONS PROVIDED > 13,000 GALLONS REQUIRED BUILDING F (COMMUNITY BUILDING) STORAGE VOLUME REQUIRED LAUNDRY FACILITIES: 50 GALLONSNVASH (LAUNDRIES, SELF-SERVICE) COFFMAN ENGINEERS, INC. 10 N. POST ST., SUITE 500 SPOKANE, WA 99201 # PERSONS = 40 30F4 PROJECT: SALMON RUN APARTMENTS FILE: 10247 Date: 7/15/10 STEP TANK SIZING CALCULATIONS 0.1 WASH/PERSON/DAY 192 PEOPLE (BASED ON 2 PERSONS/BR AND 96 BR) COFFMAN ENGINEERS, INC. 10 N. POST ST., SUITE 500 SPOKANE, WA 99201 Q= 50 GAL/WASH x 0.1 WASH/PERSON/DAY x 192 PERSONS Q= 960 GALLONS RESTROOMS: ASSUME FLOW SIMILAR TO SERVICE STATION: 10 GAL/PERSON/DAY ASSUME # OF PEOPLE USING BUILDING PER DAY: 192/2 = 96 PERSONS Q= 10 GAUPERSON/DAY x 96 PERSONS Q= 960 GALLONS TOTAL Q= 1,920 GALLONS DETENTION VOLUME REQUIRED V= 1.5Q V= 1.5 x 1,920 GALLONS V= 2,880 GALLONS TOTAL TANK VOLUME REQUIRED VOLUME = 1,920 + 2,880 = 4,800 GALLONS DETENTION VOLUME PROVIDED USE (1) 5,000 GALLON TANK AND (1) 1,000 GALLON TANK 5,000 GALLONS PROVIDED FOR BUILDING F 5,000 GALLONS PROVIDED > 4,800 GALLONS REQUIRED 40F4 "f~a-rAL ~J`/NA-~~tCC.(,-~.~~~~ ~.k~~~c~~~:.i-~o~1S h~~_ ~~~I~t~ i~;~~ ~(~ T~ E-~ = ~T~} -~-~rC, H..~`~'~ ~ ~~t~ f- ~FZ IGT"I bN E'fCA ~ ~LJ-~ SrN~"~G !-1 ~~ (~ • IJ (s~ N A~! ~ (~. 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N G I N E E R S e;;eh, checketl ln`I'~S C _~ ~y- S c ..,! ' ia. F <,/hs~,ri ~ i1'i. ~~?' 1% y (1.~~ r~V .,,: data Taub A: _ Friction Losses Chrough Plastic Fitturgs in terms of Equivalent Lengihs of Plastic Pipe Type of titling 1-I/4" 1-1/2" 2" 2.1/2 " 3" 4" 30 deg. Std Elbow 7.0 8.0 9.0 10.0 12.0 14.0 45 deg. Std Elbow 3.0 3.0 4.0 4.0 6.0 8.0 Std. Tee 7.0 9.0 11.0 14.0 17.0 22.0 heck Valve 11.0 13.0 17.0 21.0 26.0 33.0 ', Union 1.0 1.0 2.0 3.0 4.0 5.0 Sate Valve 0.9 1.1 1.4 ].7 2.0 23.0 B: Friction Loss per L00 Feet of Plastic Pipe ~) Pipe Size (in.) Rate (GPA4) 1" 1-1/4" 1.1/2" 2" 2-1/2 " 3" 4" 2 0.3 3 0.6 4 1.0 0.3 5 1.5 0.4 0.2 6 2.1 0.6 0.3 7 2.9 0.8 0.4 __ _ 8 3.6 L0 0.5 9 4.6 1.2 0.6 10 5.5 1.5 0.7 0.2 12 2.1 1.1 0.3 14 2.7 1.3 0.4 16 3.5 L7 0.5 0.2 18 4.4 2.1 0.6 0.3 20 5.2 2.5 0.9 0.3 25 3.8 1.3 0.5 30 5.2 1.8 0.6 Using a Pump Curve A pump curvehelps you determine the best pump for your system. Pump curves show the relationship between flow (gpm or Usec) and pressure (total dynamic head, or TDH), providing a graphical representation of a pump's optimal performance range. Pumps perform best attheir nominal flow rate-the value, measured in gpm, expressed by the firsttwo numerals in an Orenco pump nomenclature. At low flow rates, TDH varies from pump to pump, so it is represented as a dashed line in the pump curves. For most accurate pump specification, use Orenco's PumpSelect""software. 60 Hz Models aoo 700 .. d c soo z 0 500 a w ~ 400 v ~ 300 c n., ~O 200 w F° 100 m w C Z O a co m v ,~ en a F° 0 2 4 6 8 10 12 14 16 Flaw in gallons per minute (gpm) Flow in gallons per minute (gpmJ PF5a5o --~ PF50 Series, 60 Hz, 0.5 - 5.0 hp 400 -`- --- __.:-. w 350 -.. _ ...- ~...__ _- C 00 10 20 30 40 50 60 70 80 90 Flow in gallons per minute (gpml NTO-PU-PP~7 ©2009 Orenco SVStems°Inc. Rev. 7.8, ©12/09 Paqe 4 of 6 RETROFITTING APARTMENT BUILDINGS TO CONSERVE WATER A Guide for Managers, Engineers, and Contractors I~''~~~I~Y~I~Y p[ FNi OF U.S. Department o(liousing and Urban Development o elll~l * t ~~,~~ Office of Policy Development and Research ,„pe,e. CONSERVATION washers use from 15 to 25 gallons per nor- mal cycle. Replacement of standard effi- ciency washers presents a clear opportunity for conservation. Dishwashers use from 4.5 to 10 gallons per cycle. The older models are in the 7-to-10 gallon per cycle range; some newer models are more efficient and use right around 5 gallons per cycle. An Ohio Stace University study found that washing a load of dishes by hand required on the average 16 gallons of water. Installation of dishwashers, where fea- sible, presents a clear opportunity for con- servation. Potential for outdoor water conservation ex- ists if any of Che following holds true: • Is car washing allowed in the property? ^ If the property has irrigated landscaped areas: Are sprinklers used? Are soil moisture or rain sensors used to defer irrigation? Are there large lawn areas? Are there narrow strips of turf? ° Are there plants and trees known to consume large volumes of water? ^ Does the property have ponds or foun- tains without a recirculating water sys- tem? . Does the property have a single water meter for indoor and outdoor water uses? HOW MUCH WATER CAN BE SAVED INDOORS Now you get to use the data you collected and do a little "number crunching." To cal- culate potential water savings from indoor uses you need data on frequency of fixture/appliance use (i.e. how often are toi- lets flushed, how long are faucets and show- erheads used, how many loads of washing are done). Very few properties have such data available and developing this informa- tion is a complex and time-consuming process. In all likelihood you will have to use the "educated guesses' provided below. Unfortunately there are no definitive fre- qucncy-of-use averages for fixtures/appli- ances in multi-family rental properties. The "educated guesses" below were derived from data on single-family use and some small- scale studies on multi-family use. If you would like to review the research on which these numbers are based you can check Retrofit Water Conservation Strategies for Muitl-Family Housing at htgx//wvrvv.path- net.org/publications/watecpdf. Toilet Use Unless you have information to the contrary, assume 5 flushes per person per day. If an apartment has one 3.5 gallon per flush toilet and houses two people, you may calculate daily toilet water use In that apartment as follows: Daily toilet water use =..('L people) x (5 flushes/person) x (3.5 gallons/flush) 35 gallons Water can be saved from toilet use in a number of ways: ^ Replace toilet: A new fixture would have a flush volmne of L6 gpf. If the toi- let in the example above were replaced, 1.9 gallons per flush would be saved, or 19 gallons in one day for That pai7icular apartment. ^ Insert displacement device: Generally you should consider this option only for toilets with large tanks (3.5 gallons or Larger); the volume of water saved will depend on the device inserted. An aver- 10 age savings from displacement devices of 0.3 gallons per flush is a reasonable esti- mate. Por ten flushes a day the displace- ment device would save 3 gallons. ^ Install quick-closing flapper valve: The flapper valve is the mechanism chat lets water into Lhe toilet bowl when the flushing lever is pushed, and closes to end the flushing process. The vohmxe of water saved from installing these devices depends on the before and after flush volumes. If no better data is available, you may assume that on the average 0.4 gallons per flush are saved. For ten flushes a day the quick-closing flapper would save on the average 4 gallons. ^ Install water level adjustment: Special flushing levers are available that offer the option of a partial or a full flush. Assume that such devices will save roughly the same as a displacement device, or 0.3 gallons per flush. ^ Repair leaky toilets: You should have identified the nurnber of leaky toilets during the water audit. The volume of water that can be saved fronx repairing those leaks can vary depending on the nature of each leak; some toilets have been recorded to leak over 100 gallons a day. If there is no accurate information on the nature of each leak, it is safe to as- sume an average savings of about 5 gal- lons aday per toilet that gets fixed. Showerhead Use Unless you have information to the contrary, assume 5 minutes of Showerhead usage per person per day. Assume also that replacing a non-conserving Showerhead with aloes-flow fixture will save on the average 0.75 gallons per minute at the normal usage rate (not full open). faucet Use Water savings from installing aerators on bathroom and kitchen faucets can be esti- mated to average 0.7 gallons per minute at normal usage rates. How many minutes a day are Faucets used? It will depend among other things on whether the apartment has a dishwasher or not. For a rough estimate of water savings assume 8 minutes of faucet use per person per day for units with a dish- washer, 10 minutes otherwise. Clothes Washing Water savings from replacing in-unit clothes washers with high efficiency models will de- pend on the water use of the before and af- ter machines, which can be obtained from the manufacturers. If these numbers are hard to come by you may use an estimated savings of 15 gallons per load. The ocher question remaining is how many loads of washing do apartment dwellers typically do per day or per week? You may be able to come up with a good estimate for the prop- erty in question. If not, assume 0.35 loads (cycles) per person per day to roughly esti- mate water savings. Note that tlxe calculation in the box to tike right is not per machine but per number of affected residents. If you plan to replace 50 machines, for example, you would figure out the number of people residing in those 50 units. When you insert that number in the equation above you obtain the total daily water savings from the 50 machines. Water savings from replacing common area clothes washers with high-efficiency units will also depend on the water use of the be- fore and after machines. The frequency of Toilet Savings Darly toilet water .use - (number of residents) x (5 minutes/resident) x (0.75 gallons/minute) Showerhead Savings Daily water savings..= (numberof resrdents) x (5 murutes/resrdent)lx_ (0 75 gallons/muruie) faucet'Use ursnwasners: Daily m~aier savrngs'= (numbeCaf resrdents) x (10 minutes/resrden[) x (0.70 gallons/mrirute) In-Unit Clothes. Washer Savings Daily water savings (numbef of residents) x (0.35. cycles/resideni) x (75 gallons/c}~cle) 11 _ _ ., CONSERU/iTION ..Common Area Clothes Washer :.Savings.. Darly water savings = (number of renden(s),x (0.70 cycles/resident) x ' (75 gallons/cycle) Converting In-Unit to Common Area use for the common area machines may be available, especially if they are coin-operated washers. IC that is the case, add up the num- ber of daily cycles for all machines in the lawldry facility and multiply by the antici- pated savings per cycle Co obtain daily water savings. If the Frequency of use is not avail- able, an average of 0.1 cycles per person per day can be used (based on a recent study in Toronto, Canada, on 945 apartments). The number of residents used to compute common area clothes washer savings should be the number of people residing in units without clothes washers. `'CiOth@$'WaSh2C$ If you were Yo make Chc transition from in- ':Current ro-unrt wateruse unit clothes washers to common aroa ]aun- /numberbf residents) x dry facilities, the estimated water savings can ~n~) x be computed using the information pro- vided above. You may start by calculating '.'. current daily water use from in-unit ma- '. chines; if the volume of water used per cycle vts) x is not known, use 35 gallons per cycle as a sntJ x reasonable approximation for standard effi- ciency machines. Dish Washing %futurewater.use Dishwashers use less water than hand wash- ing. Although definitive figures for apart- ment buildings are not available, an estimated average savings of 2 gallons per person per day is reasonable, based on data From studies ofsingle-family water use. HOW MUCH WATER CAN BE SAVED OUTDOORS? Water savings frorn outdoor water use are difficult to generalize, as each property has its own set of conditions, types of equip- ment, and irrigation practices. Water use patterns will also differ significantly between hot, acid climates of the south and south- west and more temperate and "wet" north- ern areas. Por properties with extensive landscaping, you may consider getting help from a landscape architect or an irrigation or landscaping company to assess the property's outdoor water requirements. Want to tackle the assessment yourself? The followhig guidelines should prove useful: ^ Assess how much water outdoor faucets or hose bibs use. Is car washing allowed on the premises? Are hoses used for in~i- gation? In either case you may consider restricting faucet use by installing a fix- ture that requires a special key to activate the faucet. Water use at those locations may be curtailed by as much as 50 per- cent with restrictive devices. ^ If the property has irrigated landscaped areas, try to determine how much water is used in irrigation. You may compare water usage in months with and without irrigation, for example, July and rebruary. The difference in usage may be attributable to irrigatiot, assuming simi- lar levels of occupancy and no other spe- cial circumstances that can affect water usage. ^ Are sprinklers used for irrigation? Consider that drip irrigation systems could use 25 to 75 percent less water than sprinklers. . Are soil moisture or rain sensors used to adjust irrigation schedules? Consider that proper adjustment of irrigation schedules may reduce irrigation use by 5 to 10 per- cent. ^ Are there large lawn areas on the prop- erty? Consider that to provide one inch of water Yo an area of one thousand square feet (roughly the size of half a sin- gles tennis court) requires 624 gallons. Throughout the year, a lawn in California may get 30 inches of irriga- 12 From Multi-Housing Laundry Association (www.mla-online.com) Equipment The type and number of washers, dryers and other equipment required will depend on the composition of the residents and the number of apartments to be served. Washers recommended Energy efficient 14-16 Ib., heavy duty commercial washers are recommended. Dryers recommended There should always be one energy efficient, single load dryer for each washer. When more than one dryer is required, stacked dryers may be used. Double load dryers are less energy efficient and may slow the laundry completion process when used to dry less than a double wash load. Equipment guidelines Use the following guidelines to determine equipment needed for each laundry room location. The number of machines required is affected by the following: • Resident profile (families, singles, elderly) • Price charged (low price encourages usage) • Proximity of units to laundry rooms Predominant Resident Profile -----~j Families Young Working Adults Older Working Adults Students Senior Citizens Washer and Dryers per using unit 1 pair W/D per 8-12 units 1 pair W/D per 10-15 units 1 pair W/D per 15-20 units 1 pair W/D per 25-40 students 1 pair W/D per 25-40 units