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07-0135 Storm Drain Rpt 111808March 14, 2008 Revised; June 5, 2008 November 10, 2008 Proponent; Judd and Sarah Sherman (360) 458.1976 Prepared by; Lucas Johnson, E,I,T, Reviewed by; Justin Goroch, P,E, BCRA 2106 Pacific Avenue, Suite 300 Tacoma, WA 98402 (253) 627.43b7 BCRA~ I hereby state that this Storm Report for the Today's Dental project has been prepared by me or under my supervision and meets minimum standard of care and expertise which is usual and customary in this community for professional engineers. I understand that the City of Yelm does not and will not assume liability for the sufficiency, suitability, or performance of drainage facilities designed by me. R~CE!'!~d ~'+' 1 B ~f,pB Table of Contents; 1, Project Overview .............................................................................1 Z, Existing Conditions Summary ................................................................1 3. Off-Site Analysis Report,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,~,,,,,,..,,.,,,,,..,,....,,.,.,,,,, 2 4. Permanent Stormwater Control Plan ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 2 5. Construction Stormwater Pollution Prevention Plan ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 3 6. Special Reports and Studies,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 3 7. Operation and Maintenance Manual ,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,,, 3 Appendices; Appendix ~ -Vicinity Map Appendix B -Sub-basin Map Appendix C - Geotechnical Repork Appendix D -Storm Drainage Calculations Appendix E -Water Quality Calculations Appendix F -Operations and Maintenance Manual STORM DRAINAGE REPORT 1, Project Overview The Today's Dental project is located at the north corner of the Solberg Street NW and Yelm Avenue W intersection. The site consists of parcels 21124142300 and 21724142200, both of which are toned C~1 Commercial. The site lies in Section 24, Township 17N, Range 1 E. See Appendix A for a vicinity map, The project is comprised of a 0.57~acre site which will contain a newly constructed dental office building and parking lot, Construction will be divided into three phases as a means of maintaining building operations. The site will have ingresslegress points from Solberg Street, Site improvements include a Stormwater filtration system, Stormwater infiltration system, domestic water service, fire hydrants, and STEP sewer system, Stormwater improvements will be designed in aaordance with the 1992 Department of Ecology Stormwater Management Manual This was a condition of approval in the City of Yelm's Staff Report tlatedJuly 1~; 2406 for the~sit~ plan review. The Stormwater improvements include a conveyance system that filters runoff and infiltrates it into the ground through an underground infiltration structure, Stormwater runoff from the parking lot will be captured and treated for water quality using StormFilter~ cartridges, Building roof runoff will bypass the treatment system and will be conveyed directly to the StormTech~ chamber infiltration system, The StormTechO system will allow the roof runoff to be infiltrated along with the treated parking lot runoff, See Appendix B for a sub basin map of the project site, 1, Existing Conditions Summary The current site has a dental office building on the southwesterly parcel (No. 21724142300) and a single family residence on the northeasterly parcel (No. 21724142200), The existing ground cover is a combination of lawn, landscaping, and gravel with trees sparsely located around the site perimeter, In general, the site slopes from north ko south with slopes ranging from relatively flat to 4%. In the current condition, site Stormwater sheet flows from north to south, Based on the soils information and the shallow site grades, it appears that the site currenkly infiltrates all of the onsite Stormwater, The Today's Dental Bike has an upper sod and topsoil layer that ranges from six inches to one foot in depth, This rests on top of a black ash layer with gravel that ranges in depth from 2.5 to 3,0 feet, lJnderlying the ash layer is gravelly glacial outwash with cobbles and boulders, This outwash extends to the depth explored, which was a maximum of ten feet. No groundwater was encountered in any of the soil explorations, The soils are capable of infiltrating runoff at a high rate, The design infiltrate rate is suggested to be ten inches per hour. See Appendix C for the geotechnicai report, There have been no erosion problems associated with this site and we do not foresee any difficult site conditions. Based on the survey, there appears to be no fuel tanks or wells on the site, There are currently no known critical or sensitive areas on or near the project site, However, there is a septic tank and drain field that will require protection, The septic system is located near the northernmost point of the southwesterly parceh It will remain in use ko serve parcels that are adjacent to the site, but connections to it from existing buildings on the site will require decommissioning, This includes the existing dental building. A STEP tank that serves the existing building in the most northeasterly parcel also needs to be decommissioned, Both should be decommissioned per Thurston County Department of Health requirements, 3, Off•Site Analysis Report ................... . ... The site is bordered to the northwest by multifamily residences and a commercial building, Jefferson Avenue NW borders the site to the northeast, Yelm Avenue W (SR S10) borders the site to the southwest, and Solberg Street NW borders the site to the southeast, Based on soil information provided in the geotechnical report, it appears that the project area runoff infiltrates into the site soils. Since the site has such a good infiltration ability, Stormwater flow management will be achieved by utilizing an underground infiltration facility. A downstream analysis is not provided in this report since infiltration will be ukilized, It appears that the site does not accept any off~site runoff, Based on the survey and generally mild slopes, current runoff from adjacent sites also appears to infiltrate into the soil. 4, Permanent Stormwater Control Plan Flow Control System The site will utilize a StormTechO chamber system to infiltrate onsite runoff. The system consists of plastic, dome~shaped, bottomless chambers that are to be backfilled with porous drain rock. Based on the geotechnical report by E3RA dated January 5, 2001, an infiltration rate of 10 inlhr is used for the design. The footprint of the system will be approximately 11 feet wide by 61 feet long and will contain 17 chambers, See Appendix D far calculations and typical details for the system, See Appendix C for the geotechnical report, Water Qualify System Runoff from the parking lot will be treated using StormFilter;; cartridges manufactured by Contech Stormwater Solutions, Treatment will occur upstream of the StormTechO chamber system to minimize the amount of un~ treated runoff that is infiltrated into the ground, Three filter cartridges will rest inside of a 48"manhole structure that is designed to completely filter the 6-month storm event, Larger storms that exceed the filtration capacity of the cartridges will bypass filtration through an overflow weir that is located inside of the manhole structure, Each filtration cartridge is 27"tall and has a maximum filtration flowrate of 2z,5 gallonslminute, The filtration media used in the cartridges is zeolite, perlite, antl granular activated carbon (ZPG), zPG media was chosen for the Today's Dental site because it is suggested for treating sediments, oil and grease, total nutrients, complexed and soluble metals, anthropogenic organic contaminants, and ammonia, See Appendix E for the water quality calculations, conveyance System Analysis and Design Runoff from the parking lot is captured by a series of catch basins and conveyed to the StormFilter system for water quality treatment, The runoff is then conveyed to the StormTech®chamber system where it is infiltrated. Since roof runoff does not have to be treated for water quality, it is captured -.-..~ _ and conveyed separately from the runoff from the parking lot, It is conveyed directly to the StormTech~ chamber system, All conveyance systems are sized for the 100~year storm event. Manninq's Equation was used to determine the maximum flowrate that the last pipe run in the system could tolerate (assuming uniform flow), The anticipated maximum flowrate for the 100~year event was then checked against the maximum allowable flowrate that the pipe can tolerate. The 100•year storm event flow rate is less than the maximum allowable flowrate, indicating that the pipe size chosen (8" diameter) is capable of conveying the 100-year storm event, If the 100~year storm event occurs, it will create a flowrate that fills the pipe to a depth of 0,3 feet (approximately 48,3% fuil~, See Appendix D for conveyance calculations, 5, Construction Stormwater Pollution Prevention Plan The Construction Stormwater Pollution Prevention Plan (SWPPP) is a separate document, It will be submitted along with this storm drainage report. 6, Special Reports and Studies A soil analysis report was completed far the Today's Dental site by E3RA, Inc. A copy of the geotechnical report can be found in Appendix C, 7, Operation and Maintenance Manual An operation and Maintenance Manual can be found in Appendix F. APPENDIX A VICINITY MAP ~~ll APPENDIX B SUB•BASIN M,4P v~~~ ~~a f~ ~f ~~, ~~~ v~ o zo 40 60 Asa 1 "=40' BASIN AREA 1 0,16 kC 2 0.38 AC BUILDING ROOF 0.13 AC TOTAL 0,54 AC z. w ;~ ~~, U, a ~ r w G. ~~ ~, 00~~~; a F ~ ~r ~, 5 ~~ 1 n. Q m yz ~U ~m m n u u z c~ x a ~, 1 fi 0 n c g ~ m i u. i i ~: 0 i ~ ~' i I to ,~ ' ~~ :: y ii= ~~.; c APPENDIX C GEOTECHNICAL REPORT ao aox 4480 Taco~r,a ,^'A °544=. 263 63.-9400 263-6379401 tax ~3 Iairuzay ~, 2006 T06391 Yelm Dental Center, L~1,C S02 Yehn Avenue t'w'esi Yolm, lYA 98479 Attention: Dr. Sarah Sherman Subject: GcotechuicalEngineeringReport Planned Commercial Developmont S02 Yeim Avenue 1~'est, Pliv' 21724142340 0~ Solberg Street PAN 21724142200 Yolm, ti9ashington Dear Sarah; E3R4 is ploasedto submitthis repod~describingthe resuhs ofour geoteehnicalengineeringevaluationforthe msidential development planned at S02 Yelm Ave Wost and 107 Solberg S0'oet in Yelm, ~rJashinglon. This report has been prepared for tare exclusive use of Yehn Dental Center, I,I.C acrd their consultants, for spocific application to this projoot, In aceordaime with generally accepted geoteehnieal onginoering practice. I,0 SITE AND PRpJEC'F DESCRIPTION The planned commercial development is located on the comor of SR Si0 and Sti4'Solberg St. in Yelm, Washington, as shown on the euclosod Goeation Map (Figure 1), It eonsists of two rectangular pal~oels that measure about 80 foot fronting SR SIO and 300 feet fronting Solberg Street. Tho project site is currently bordered by SR S 10 to the southwest,le~'erson Ave to the northeast; acrd Solber St to the eask Surfaeo topography is relatively level. Plans call for the removal of the exisihig iromo and dental office and construction of a rew dental office, associated parking, and a storm water inflhntion facility. The properties will have access from Solberg St, 2.0 E~I,ORATORYMETIiODS 1~'e explored surfaco and subsurface conditions at fho projeot site on November ? 8, 2006, Our exploration program comprised the following elements: ' A surface reconnaissance of tthe two parcels; ' Ten tort pits (de,ignated TP-1 througi. TP-3), advanced across tiro situ; ' Ono Grain Size analyses of on~sife sails; ' Three Infiltt~ataon Tests; and January 6, 20u7 E'RA Inc. TOo39"1 i Yelm Lrental A review of published geoiogie urd soismologio ;raps nerd Iheratura. ;able 1 summarizes the approximate fsnational locations acrd te~rminatiorr depths of our subsurface explorations, and;?igurc 2 depicts their approximate reiative locations. Tha follor~ring toxt sections describe the procodures used for axoavation of test pits. TAD);); I AYPROXIIIAT)J LOCATIONS AND DEPTIIS OI' )/XPLOIZ~TIONS Teranination Depth );xploration p'unctional Location (feet) ~TP•1 Southwestsite 8 sTP~2 Central past oast silo 10 ATP-3 Central site 10 ~ Iuoludas ioftltration test Tita specific number and locations of our explorations were selected in relation to the existing site features, under the constraints of surface access, and underground utility conflicts. It should be realized tlrat the explorations performed and utilized for this evaluation reveal subsurface conditions onlyatdiscratelooations across fheprojactsita andthat aeiual conditionsin other areaseouldvary, Furthemrore; tlta nahn~e and extent of any such variations would not become evident until additional axplorationsareparformedoruntilconstruetionactivitieshavobegur>. Ifsigniflcantvariationsareobservodat lhattime,wemaynaedtomodifyouoonalusionsandre~oommnndationsoont~nadinthisroporttoraflootthe actual situ conditions, 2,I TestPitProcedures Our oxploratory fast pits were excavated witwr asteel-tracked excavator oporatad by an irrd2pendent fum working under subaoniract to C3RA, An engineer from our fmr confinuously observed the test pit excavations, logged the subsurface conditions, and collected samples, After we logged each test pit, the excavator operator bacl~lled if witli exoavatod soils and tamped tlra surfaaa, The enclosed Test Pit I/ogs indicate the vertical sequence of soils and materials en~untared in each iest pit, basedonourfield classiCcations. Where a soil contactwas observedto be graflational orundulating, ourlogs iudicats the average contact depth. Wo ostimated the relative density and consistency ofthe in-situ sails by means of the excavation oharactoristics and the stability of the test pit sidewalk. Our logs also indicate the approxhnate depths of any sidewall cavurg or groundwater seepage observed in the fast pits, as wall as all sample numbers and sampling locations, 2.2 Infiltration Test Proeedares We performed fallinghead inrltration fasts atadepth of about 1 feet within testnirsTl'-1,2, and3. All faLing head tests were performed hr general aeaordance with the failing head typo infiltration tasting proeedure~ described hr tlra;JPA publication On-site 1Jrasterr~ater 1 reairnant and DisposalSysiern f98Q dasoribod bolow. January 5, 2067 E3PA. Inc. TOfi39? 1 Yelm Ceotaf 9 6-ineh•diamztzr PUC~pipe was tamped 3 to ~ inches into thz soil of the upper part of Che infiltration layer, lien 2 inches of coarse, clean drain rook wasplaeed at the bottom of fiiz pipe to prevznf securing. Sail was piacedandtampedoutsidethepipaforstabilizationandtoprevznCupwof[ingofCostwateraroundtlsepipo.The pipe was thin filled twice with 1 foot of water to pre•saturatz thz test sails. Because, in all eases, l foot of waizr inClhated the test sails in loss than 10 mivutzs; furl~li~r saturation was deemed unneoessaJy and the i~ilfrationtestproceeded. The pipa was than 611zd with 6 inches of water, and; bzcause site soils woro found to be rapidly permeable, the Cime rzquired for inClh~atioo of the entire G inch eolmnn of wator was rzcordzd, We repeated this proeeduro huee dines at oath Pest loeation and uszd only Else slowest of dio 3 recorded infiltration rates in our aualysis• 3,0 SITE CONDITIONS Thefollowingseetionsoftextpresentoarobservations,measurzments,findings;uidintzrpretatlonsregarding, surface, soil, groundwater, seismic; liquefaefion, and infltration conditions. 3,1 Surface Conditions The project sift is relatively level with no noticeable ehangz hr elevation• TheS02YzlmAvetiVestpareeleurrentlyhasanexistingYelmDzntalO~ioeand 101SoibergS~eeteurrently has a home on the lot. The remainder of the sites are yard or parling. Vegetation orlSite consists of grass and some small yard trezs, No signs of surface flow, such as stream channels or zrosional soars, werenoted during our reecnnaissanee. No ponds are onsite. No seeps or springs were observed, 3.2 Soil Conditions Ouron-siteexplorationsrzvealedfairlynearlyunifoimnear-surfaoesoilconditions, Generally,weobserved au upper sodatid topsoil layerthatrangodin thioloress from'rito abit lessthan 7 foot iotwsicknessoverlayhrga black ash layer with gravel ranging to a dzpth of about 3112 to 3.0 fezt. L`nderlying the ash layer, wz observed, to the termination of our explorations, which reaehzd amaximum ofabout 10 fait; gravely glacial ouhvash with cobbles and 6oulders• Thz soils appeared to become somewhat sandier and slightly less to the uoiih and west. Caving was noted at depths of about 4 lit to S feet hs the test pits, suggesting that water will readily infiltrate at these depths due to Che nature oftha soils and lank of silrs• The enclosed exploration logs provide a detailed description of the soil shata encountered iu our subsurface explorations, 3.2.1, Eaborato~ ~ T~tl'~o Our Grain Sizo Analyses of the sandy gravzi in test pits TP-1, found ~ti~ith.3r the zoue wlrero infiltration wilt likely occur (7 font below current grades) indicate that the sill eontznt is in the range of 5 peroent• uie iiivrSiliie content vi SuilS wiuGiiiiitc ZOirc ufiTuihiati"vii is abvut i pirvciu &$ i'vBil.'~Ve iIliei~~r[t iiw5tof iiie upper soils as being close to optimum moisture, The enclosed laboratory testutg sheets graphically present our tesC insults, and Table 2 sumnsarizes i'Isese results, January b, 2901 D3RF,, Inc. T96?97 i Yelm De~tzl TA~I,~ ~ __~ I,AI301tATORY ~');ST I~S>/ZTS FOR NON-ORGANIC ON-SIT>; SOILS '~ Sail Saanple and Moisture Gravel Content Sand Contont Si1tlClay Depth Content (percent) (pca~ceatt) Content ( ereent) (ercent) ~ Tl'-l, S•l, 7 feet ' S.l 70 24,8 52 3~3 Croundwatns At'~e fima of our reoonnaissanee (idovember 18, 2DOb), we did not observe ~oandwater in any of our eXplorations, which e~i~ertded to depths of up to 10 feat too significant mottling was observed. 1t is not anficipated twtat ground wator will be encountered during typical onsife oonsiruci'ion activities. 3uS Seismic Conditions Basedonouranalysis ofsubsurfaoeazpiorationlogs and ourreviewofpuhlished geologicmaps; we interpret soil condifions on the siteto correspond with a seismic site Blass So, as defined by Table Ibl S.1.S of the 2003 Inter~natianal BuildingCode (I13C). According to the IBC, the site is Seismic Region 3. 3.6 Li uefaction Potential I,iquefactioa is a sudden increase in pone tt~ater pressure and a sudden lass of soil shear strength caused by shear strains, as could result from an earthquake. Research has shown that saturated, loose, fine to medium sands with a fines (silt and clay) content less than about 20 percent are mostsuseepfible to liquefaction. IrJa did not observe easily liquefiable soils onsite, 3_7 Infiltratiooos A storm wafer infiltration facility is planned for the she. In our tluee test pits located in tho vicinity of ibis facility,testpits TP-1; 2, and3, we observed loosesiltysandygravelwith afines contentihataveragodabouts percent. Accordingto the U.S,D.A.'fe><luraf Triangle, our laboratoryana(yses ofthis soil indicate that itis a gravel, course sand type A with art irtfltration rate of 1 minutelinch. Tho rosults of our htfiliration tests are presented in Table 3. Because intltration was moderately rapid, we recorded thetime necessary for a G hrch highcolumrr ofwaterto infiltrate completely as discussed in section 2.2 above, Based on our field testing, the Average Infiltration Rate forsoils at a depth of i feet is ~.0 minutes per inch. After incorporating a Factor of Safely of 2, we recommend a Design Infiltr anon Rate of 6 mhtutes per inch (10 inches per hour). TA13I~)i; 3 1+I);I,D 1NFII,TATIONTBST RDSC1SsTS Test Location Depth below ~ existing grades Freld Infiltration Rate for 6 Number (feet) inch Column T-1 Tp•1, parking area 7 20 rninll6 inches T-2 TP-2, front yard of home 7 i0 minl6 inches T-3 TP-3, back yard of home ~ 1 ' 8 mir;'6 htches January ~, 2007 E3RA~ Inc. i 063971 Yelm Dontal d.0 CONCLGSIONS AND I~COMIUIENDATIONS Plans call forthe preparation of anewdoutal offioe, paved parkirrg, and uriiltration of storm wateran site. Wa offer the followhrg conciusiens and reconunendations: feasibililw; Based on our field explorations, research, and analyses, tho proposed devolopment appears feasible from a geotechnical standpoint provided that fire recommendatirnrs hrSection 4 and in this report ale followed. Foundation Options; lUo recommend conventional spread footings suppoit~ed oa fu~rnly compaeted nativo soils. Recommendationsfior spread foothrgs are provided in Section 4. Floor.O bons; Werecommend either a ooncreteslab-orr-grade orjoist-supported floors for tlreproposedcommercialstructure. Someov¢r•excavationwillbenecessaryforslab-on-grade floors. Recommendations far slab-on-fade floors are included in Section 4. Onsitelnfiltration:BasedonouronsiteinGlti~ationtesfsandsoilsanalyses;werecommendat Design Infiltration Rate of 6 minutes per inch for sails in the vicinity of the plarmed infiltation facility. As haltPavament;Shucturalfillsubbasesappcardonotappeartobenecessaryprovidedthat sub-grades are compacted to 9S percent maximum dry dsnsity, A pavement section, consisthrg of 2 inches of asphaltpavemeut over a ~ inch crushed rook base; is recommended for the planned parking area Tho folloaving textsections of this reportpresent our speciflo gootaolmioal conclusions and recommendations concerningsitepreparation,spreadfootings,slab•on-gradefloors,drainago,subgradewalls,andshucturalfill. The WSDOTSta~rdardSpacificationsandStmrdardPlanscitodhereinrefertoWSDOTpublieationsM41-10, Standard Speeifieations for Road, Bridge, and Municrpai Conrlruction;and1921-01, Standard Pfans for Koad, Bridge, and!P1unicrpal Construction, respectively. Q,1 SitePre aralion Preparation of theprajectsite should involve erosion control, temporary drainago, clearhrg, stripping, eutOng, f fling, excavations, and subgrade compaction. )/rosion Control; before new conshuetion begins, an appropriate erosion control system should be installed. This system should collect and fSlfcr all surface run off through either silt fen cing or a series of proper)}~ placed and speared straw bales, lrJe anticipate a system of berms and drainage diichcs around constuction areas will provide an adequatecollection system. Ifsiltfenchrg is selected as a fdter, this fencing fabric shouldmeetthe requirements of WSDOT Standard Specification 9.33.2 Table 3. In addition, silt foncing should embed a nrhrimum of 6 hrohes below oxisting grade. If straw balillg is used as a filter, bales should be secured to the ground so tltatClroywill net shiftunderthe weight of retahred rv~ater. Regardless of the silt filter selected, an erosion controlsystem reQuires occasional observation acrd maintenanoe, Specifically, holes in the fiber and areas rt~here the filter has shifted above ground surface should be replaced or repaired as soon as they are identified, T~orar ~ Drama c: tide recommoud intercepi~ing and diverting any potential sources of surface or near-surface v,~ater within the constructien zones before stripping begins. 13eoause the selcatien of an appropriato draurago system will depend on tiro wator quantity, season, weather conditions, eonshucien January 5, 2001 EARN, Inc. T00397! Yalm Dental sequence, acrd contractor's methods, foal decisions regarding drainage syst~ns are best made in the field at tho time of construction, based on our emrent undorstanding of the consh~ction plans, sm~Face and subsurface conditions, we anticipate that curbs, berms, or ditches placed around the work areas wi(ladequately iutctr~pi~ surace water runoff. Clearin and SirippID~g° Aftor surface and Hoar-surface water sources have bezn oonlrolled,tho oonsh~uoiion areas should bcoleared aJ~d stripped of all daft, and topsail. Ourexplorafons indicatethatathie);ness of yito l fooC of topsail will be encountered across tho site. Also, it should be realized t!~.at iftlte stripping operation proceeds during wet weathor, a generally greater stripping depth might be necessary to remove disturbod moisture/sensifvesoils; therofore, stripping isbest performadduring aperiod ofdry weather. Sit~;;zeavai~ions: Bas~donourezplorafior>s,weezpactthatsiteezcavationswilleocouuterlooscsoilsthat can be easily ozoavated by conventional earth working equipment. I)ewaterin : C~'e do not anticipate dewatering to be necessar;~ on this project. Tem ore Cut Slo ~s: All temporary soil slopes associated with site cutting or ezoavations should be adequatelyhrclined topraventsloughingand collapse. Temporaryeutslopes insitesoils should beno steeper than L'h H:IV, and should conform to I~ISHA regulations, Sub r~Cornpaetion: Exposed subgradas forfootargs and Floors should be compacted to of rm,unyielding state baforenew concrete orfll soils are placed. Any localiaedzones of looser granulal~soils obseivad within a subgradc should be eernpacrRd to a donsity commensurate with the surrounding soils. In contrast, any organic, soft, or pumping soils observed within a subgrade should be overezcavated and replaced with a suilahle shuctural fll malarial, Site_ rte: Our oonolusions regarding the reuse of on~sita sods and our comments rogarding wet weather filling are presented subsequently, Regardless ofsoi] type, all fill should be placcd and compacted according io our rceommandations presented iu the SiructuraCFilf section of this repork Specifically, building pad fill soil should be compacted to a uniform density of at least 9S percent (based on AST'vI,D-1 SS1). On-Site Soils: Weofforthefollowhrgavaiuationoftheseon~sitasails~rolationtopoteutialusaasshuotural fll: Sur reialSod arrd To soil: The sad and topsoil mantling the site is not suitahle for use as structural fill under any circumstances, due to hi~r organic content. Consequently, those matcrials can be used only for non-structural proposes, such as in landscaping areas, ~lnek ash: The black silty sandy gravel that underlies tho site is erurently near optimtmi moisture eontentand might possibly be reused as structural fill, depending on conditions at timeof construction, Itis moremoisfuresensitir~eChentheounvaslr below andwill bediiflicult to reuse during wet weather conditions, CrCaeial puiwas)r: Tiro sandy gravel with cobbles and boulders that underlies the site is eun~antly nea~~optimmn moisture contentand eau bereused as s~'uetural fill. This soil is loss moisture sensitive and can likely be roused in wet woathor conditions. 4,2 S read)!ooti~r s ht our opinioi~t, conventional spreadfootings wilt provide adequate support' tar the proposed structure if the subgrades are properly prepared. 1~c offer ftre following comments and recommendations for puaposes of January G, 2007 r3R,q luc TOG397 i Yelm Genial footing dosign and conshuction pootina De the and Widths: par d~osi~ and erosion protection, the base of all exterior foatillgs should bear aC least 24 inphas below adjacent outside grades. To lunit post-ponstruptian settlemonts, pontinuous (wall) acrd isolated (colunur) footings should be at bast 18 and 24 inches wide, respeptively )3earin~Subaradas and Hearin Pressures: The native ashy layor and glacial ouiwash undorlyingthe proposed building footprutC ai~ subgrade elevafioos will adequately support spread footings. In general, before footing generate is placed, any lopalized zones of loose sails oXposed across the footing sub~adcs should be compactedto a firm, unyielding pondition, andany localizedaonesofsofi,organic; ordebris-laden soilsshould be over~apavated and replaced with suitable structural. d11, Sub ade0bservation: Allfootingsubgraddsshouldconsistofeithorfirm;unyielding;nativasoilsorsuifablo structural fill mai~erials. Pooiiags should never bo pastatop loose, sofl~; or frazon soil, slough, debris, existing unpouirolledfll, orsurfacescovered bystanding wator. lrJprecernmeudthatt~e pondiiionofallsubecadasbe obsen~ed by aIr E3RA ropresentaQvo before any concrete is placed. Hearin Pressures; hrouropinion,fbrstaticloading,footingsthatbearonproperlypreparedsubgradespanba designedforthemaaimumallowablesoilbearingpressuresof2SO4psf: Aone-thhdincreaseinallowablosoil bearing capacity may be used far short-farm loads erected by seismip or wind related activities. Pooiin SotClements: We estimato that total post-ponsttuption settlements of properly designed fOOfings bearing on properly prepared subgrades will not ezppad 1 inch. Differential settlements for comparably loaded elements may approach one-half of this value over horizontal distances of approximately SO~faet. Footle and StemwallBackfilh To prouide erosion protection and lateral load resistarreo, we rpponunendtbaC all footing excavations ba backf'illed on bot)r sides of the footngs, retaining walls, and sComwalls ad~er the conereto has cured, Fitherimparted smtcturalfill ornon-organic on-site soils can be used far this purpose, contingontonsuitablemoisturenontentatilrotimeofplapemont. Regardlessofsoiltype,allfoo+angbaol;fill soil should be compacted to a density of at least 90 percent (based on ASTM:D-1 Ss1), pateral Resislanpe: poodngs that havo been properly bapkfifled as rer~mmended above will resist latoml movomonfs by moans of passive earth pressure and base fription. We recorsnt~pnd using an allowable passive earth pressure of 300 psi for lwae granular backfill.l>rre recommend an allowable base fripiion coefficient of 03S for granular soils, d~3 Slab~Ou~ Grp In our opinion, sail-supported slab-on-fade floors can be used m the proposed structure if the subgrades are properlypreparad. Weofferihefollowingcommentsandropommendationsponpemhrgslab-on-gradofloors, F'IoorSubbase: Structuralfilfsubbasosdonotappoartobeneededuirdorsoil-supportpdsla6-on-gradedoors,if the oxistiug naCive subgrade pur be thoroughly compacted. If subgrade pompaction is not feasible, we reconunend that granular f II be plaoed to a depth of l2 hrches below finish subgrada. Capillan Break and Va or Battier: To retard the upv,~ard winking of,~outtdwafar beneath the floor slab in areas where moisture sensitive door covorings will be used, such as oidices, we recommend Chat a capillary break be placed over the subgrade, ldeaiiy, this papillary brook would consist of a 4-inph-think layer of pea g~~aval or other mean, uniform, well-roundod gravel, but ploa;r angular gravel can be used if ii adequately provpnts papillary wieki:tg, In addition, a layer of plastip sheetitrg (suph as Crosstuff, Visquoen, or Ivloistop) shouldbe placed overthoeapillary breakto seneas avapor barrier. Dururgsubsaquantcastingof dreponprete slab, the pontractor should exercise pare i'o avoid puncturing t(tis vapor barrier, January ~; 2007 T063971 Yelm t7eotal w3RA, Inc, 4A llr~iua c Systems We offer the fallowing reyommyndations acrd comments far drainagy dysi~ for yonsirucfion purposes. Fyrimeter Drahrs; We recormuend thaC lira buildings be euoh~cled wirli a pyrimai~r drain system to collect seepagywater, Thisdrainshouldconsistofa~-inch-diameferperforatadpipetis~ilhina:remalopeofpeagrayel or washed royk, yztanding of least 6 inches on all sides of the pipe, The gravel envelope should be wrapped with fltar fabric to reduce thy rnigralion of fines from the surrounding soils. Ideally, the drain invertwould by installed no morn than S broltys above the base of the parirnytyr footings, Subfloor Drains:l3ycause floor subgradas will on a a auular material, we do not ryrammend the use of subfloor drains. Dischar e Considyrations: If possible; all perimeter drains should discharge to asuitably dishcarge location, hunoff Water: Roof runoff and surface•runoff water should not dischargy into the pyrimeter drain system. Instead,thesysoureesshouiddisyhargeiutosyparatatightlhrepipesandbyroutydawayfromthebuildhrgtoa sform drain or other appropriate location Gradin and Capoina: pinal site grades should slopo downward awa}~ frornrlra building so chaC runoff water will flow by gravity to suitably colleetion points, rather than ponding near the building. Ideally; the area surCOUnding the building would be capped witirconorete; asphalt, or low-permeability (silty) soils to rninimiae orprecludysurfaye•waterinflt~ion 4.S As halt Pavement Since asphaltiy pavements will be used for thy parking area and, possibly, driveways, we offer the following comments and rayommendaiions for pavement design and rmnshuytion. Sub ode Pre aralion: All sail subgrades should be thoroughly aompaytad;then proof-rolled with a loadyd dumptruckorheavycompactor. Any]or~livydzonysofyieldingsubgradodisylosedduringtlusproof rolling operation should by over eXyavarydto amaximum depth of i2 inches andrepiacyd with asuitably struytural fill material, Pavemynt Materials: For the bass yourse, we recommynd using imported crushed rook Native materials shall be adequate as a subbase, Conventional Asphalt Sections: A convyntional pavement syyiion typically eomprisys an asphalt concrete pavement ovyr a crashed roek base course. Csrsing fre estimatyd design values stated abovy, wy ryyommand using the following com~entional pavement sections: Minimum Thickness FavementCoursa ParkingAraas High Traffic and Driveway Areas Asphalt Concryte Pavymeut 2 inches 3 inches ~rncl ed Rnek Roc, d in,hec (, inrhy~ Cn~anular Fill Subbase (if uyedyd) 12 arches l2 CompaotionandObsyrvafion: ,411subbasyaud'uasyooursymarerialshouldbyyornpaytedtoatleast93peroant January 5, 200i E3F~F, Inc. TOo397 ! Yolm dental ofthoModifiedProotormaximum drydensity(AS'~f D~ISS7), and ailas~plralteonorcteshouldbocompacted to at bast 92 poroont of the Rice value (ASTM D-2041), 1~e rocommond that ap E3FA representative be retained to observe the compaction of each course beforo ~y overlying leper is pieced. par the subbase and pavemert course, oompaetion fs bast observed by means of frequont dansity~ tosthrg, par fho base course, methodology obsen~ations and Irand•proburg are more appropriate than density testurg, Pavement[,ifeandMaintenanee: Noasphaftiopavomontismaintenanee•Gee, Thaabovodesoribodpavetnont sections present ourmipimum rooommendations far an average level of performance during a?0-yeardosig~ life; therefore, an average level of maintonapee will likely be required. purthennore, a20-you pavomont life typically assumes that an overlay will be placed after about 10 years. Thicker asphah andiorthickor base u~d subbase eourseswould offer bofterlong-teen perfarnrance, but would Bost more initially; thhutor courses would be more susceptible fo "alligator" cracking and otter failure modes. As such, pavement dosigu can be considered a compromise betweon a high initial cost and low maintenanr~ costs versus a low initial oust and higher maintouanoe costs. 4.6 Structural Fill The term "structural fill" refers to any placed under foundations, retahring walls, slab-on-grade floors, sidewalks, pavements, and other structuros. Our continents, conclusions, and recommendations concoming structural f if aro prosented in the following puagraphs. Materials. Typioalstntcturalflllmaterlalsutpludecleansand, gravel,peagavel,washedmok,emshedrock, well-graded mixtures of sand and gavel (commonly callod "gavel borrow" or "pit-mn'"),and miscellaneous miXfures ofsilt, sand, and gavel Recycled asphalt, concrete, and glass, which are derived~from pulverizing flrepuentmaterials,uealsopotontiallyusofulasshuoturalfillincerrhainapplicatiops, Soilsusodforstrucgrra': fdl should uotcontainapy organic matter ordebris, nor anyindividualparticies geaterthanabout6 inchos in diameter, Fill Placement: Clean sand, ganulithic gavel, crushed rook, soil mi~ures, and recycled rnarerials should bo planed in horizontal lifts not exceedurg 8 inches in loose thickness, and each lift should be thoroughly compacted with a mechanical compactor. Com ae~tion Criforia. Using tlto Modified Proctor tost (tyST'kd;D-ISS1) as a standard, we recommend ti~at stuctural f 11 used for various on-site applications ba compacted to the following minimmn densities: Fill Application Minimum Compaction Footing subgade and boaringpad 95 porcent Foundation baekfill 90 percent Slab-on-grade floor subgade and subbase 95 percent Pavement Subgade (upper 2 feet) 9S percept Pavetent Subgade (below p feat) 90 percent Sab ode Observation and Com raetiou Testn ; ]regardless of material orlocation, all structural fill should be plaeedoverfirm,uuyieldingsubgadesprepa~~odinaoeordureewiththcSiiaPr¢pm~at~onsoctiopofthisropoit, The condition of all subgrades should bo observed by geotoclrnical porsonnel before filling or eenshuelion bogins. Also, fill soil eompaotionshould beverified bymeans of in-plane density tests performed during fill laeelllerli ,.,. il,~~ ~,1 A', 'I ,,,,....,~ a:..u ., 1. ,,. 1 • a ~,. mil„ I p au ula~ auequaey of a0i1 ww~aeuvai cfiuiiS iilay" uo cJaiu&~Bu a~ e&1i11n'ur~ progiES$eS, Jarnaar; C, 2CC? E3RA, loc. T0639? 1 Yelm ~eotal Soii Moisture Considerations: The suitability of soils used for structura(fll depends primarily on their grain-size distribution and moisture eoniznt whoa they are placod. As the "fines" eonterrt (that soil O~aotion passing the U.S. No. 200 Sieve) increases, soils beoomo more sensitivo to small alrangos in moisture cenfent Soils containing more than about S percent fines (by weight) cannot be r~nsistently compacCed to a firm; unyielding condition when the moisture content is more Oran 2 percentage points above or below optimum, Pot Cll placernont during wet-weather site work, we reoommend using "clean" CII, which refers to soils that have a f'mes content of 5 poroent or less (by weight) based on the soil fraction passing the CIS, lv'o. 4 Sieve. S.0 R);C0~It1dENDED ADDITIONAL SERVICES Because the future performanco and integrity of the structural elements will depend largely on propor site preparation, drainage, fll placement, and construction procedures, monitoring aad testing by experioneed geoteelmical personnel should be considered au integral parr of the construction process. CorlSeque~ntly; we recommend fhatE3RA be retained to provide Ore following post-report services: Reviewa]loonsp~uotionplansandspecifioationsrovor>fy~ihatourdosigneriteriapresznfzdin this report have been properly integrated into the design; Prepare a letter addressing relevant review comments (t'required by t<le City of Yehn); Check all completed subgrades for footings and slab-on-grade floors before concrete is poured, in order to verify Chair bearing capacity; and Prepare apast-construction letter summarising a(I field observations; inspections, and test results (if required by the City of Sumner). 6.0 CLOSCIRE The conclusions andrecommondations presented inthis report era based, in part, onChe ezploraiions that we observed forthis study; therefore, ifvariations in Chesubgradeeonditionsareobsen~ed at a latertune, we may need to modify this report to reflect Orose changes. Also, bocause Ore future performance and integi~ity of the project elements depend largely on proper initial site preparation, drainage, and consurrction procedrues, monitoring and testing by experienced geoteclmical personnel should be considered an integral part of the construction process. E3ItA is available to provide geotechnical monii~oring ofsoils Orroughout constmction January 6; 2007 T063971 Yelm genial E'RA. loc. Weappreeiafe flat opportunity to ba o£ser<~ice ou this project C£you have any questions regardingthis report or any aspects of the projeot, please £eel free to oontaotour once. Sincerely, E31~, Inc, F~°C~~~ ~ j~~~F ~ S~~y ~„1! I! r ~+r ~~ P•' q ~~ Y It~sk ~~' `~a°, 4 y n , ~" ~~~~' IZ ~~~ ~ ~- Casey R. Lowe; E.S.T. lames E Brigham; P.E. Staff Engineer Principal Enghreer CRIIIEB Enclosures, Figurel ~.. La~a~'onMap Pigure2 -Site&Esplorationl'!an Attaehment, TestPitGogrTP-1 throughTP-3, SieveAnalysis January 5, 2007 E3RR, Inc. T06397 i Y21m Dental TTST PIT SLOGS -Y~Im Dental Offioo De th feat Material Deseriution Sample No, Test Pit TP•1 Locatlou: Pariuug at ezisturg dental office Approximate ground surfano elevation: Unknoum 0,0-0.1 Crushadroek 0.7-2.0 Medium dense, moist, blank ash silty sandy g~~avel with bau'dnrs acrd cobbles (SP-SM) S-1 2.0 ~ 9.S Medium Dense; moisC, tan sandy grvei w;~silt, Bobbies, and boulders (SP). S? ~, Test pit terminated at approximately 9.5 feat ~ Moderate caving observed at 4.S feet No groundwater or mottling noted lle th lent MaterialDESrripton San. iple:Vo, TestPit TP-3 honation: Existinghomo&antyard Approximate ground surface elevation: Unkuouaa 0.0-O.S Tap Soil 0,7 -2.S Mndium dense, moist, blank ash silty sandy ~avcl with boulders and nobbles (SP-SM) ?.S -10.0 Medium Dense, moist, tan sandy gravel wlsilt, cobbles, and boulders (SP). S-1 Test pit terminated at approximately 10 feet Moderate eaving observed at 5 feet i`ro groundwater or moti~ling noted I)e th feat Materialllescription SamnloN°, TrstPitTP-3 kocation: Existing home backyard Approximate ground surface elevation. Unknown 0.0-0.6 Crushedrock 0.6 -2.D Medium dense, moist, blank ash silty sandy ~~avel Ns~boulders and nobbles (SP•SM) 2,0 -5.S Medium Dense; moist; tan sand}' o avol wilt sift, nobbles, and boulders (SP). I S.5 -10.0 Medium Dense; tan sandy graveVgravelly sand (SP). S-I Test pit terminated at approximately i 0 fnnt ~ Slight caving obsen~ed at SS feet I fro groundwater or mottlinue noi~ed Dain Excavated; 1 ili8i06 Toggod'oy: Citi, C N Q~ 7 i~ F~ ~N ~~ C c C ~ 0 j < L ,~ N ~ ~ (~ N a N a j c m a N N ro ~~ m c mm ~ "' Na ] M m 0 0 0 r 0 0 r 0 v N N m 0 ro a. Buiss¢d auaaaad 0 0 0 0 0 0 0 0 0 0 p~' O m lC ~ N p c ~ N ~ APPENDIX D STORM DRAINAGE CALCULATIONS STORMWATER MANAGEMENT MANUAL FOR THE PUGET SOUND BASIN ITI~1-4g FEBRUARY, 1992 STORMWATER MANAGEMENT MANUAI, FOR THE PUGET 50UND BASIN 124 9^---ti_,~ 123 122 121 ,~ ,~ , . a SU ~~ ~ ~,~ "l 4S Iv r I .,~; . ~ S5 u 1\1 ° ~RIp4iHpR~Qp~,POfi?SIpNI', ~ U„- I Ql~p ;~~ 80 h~'~ ~I~`~'y i ~ ~, 16~,, ~~~ 6 ~ ' (s I) i ~ ~l ~ ~~,1 8 ~ , ~ ~ ~ `~li ~ °~ ~ ~ ,~ .,.! ru I o j 80:1 ~; ~~. ~ ~~ ~~ l ~ .~ r ~1Y ~~ .~ ~~~~ I 9J~ N I v~~~1~ ,.~~lln`11 ~I p7~I/ .''r~y~nl~ ~ ~ /~4 1 66 ~ n rRS n.~r n~Oh 'JY ~ SI .. 1,/ / I I '• WASH1NGtgN 140, J ~lo~ I I ,0 I~~ 6° ! ` ~kl 10 '0 10 10 90 4d I ~ ~ ~~ ~ ENE ' -~ MMES 40~ ~ ~ a ~ IMDf I i 61gUfC$0 46 "~, Npgq gTlgS 2, Volum¢ IX I ISOPLUVIAL$1F 100•YR 24•HR PRECIRIT T 6° S5 B0 66 ! Prepar¢dbyus: Dpparlmeo ~n IN TENTH$ OF N INCH ~ ION Na6apalpc¢aokaodglmoaphe~cgymim'atraHan r' i NalionalWepth¢rSeNicp,pNiceoflHytlrology Prepared for U.S, pepartmapt of A~riculturg ~---.:~ Scil Coos¢rvalio~ Service, Eggire¢rlog pivisioo 124 123 122 ' 12i III-1-46 r^EBRUARY, 1992 StoimSHEOCaloula'ions JobNa~iP~cjeel:Ob2d21oday's~enta~ Date;031U108 6x11 StnrmTECH Routing Summary 100 Mafch Q; 0.1595 cfs Peak Oul Q; 0,1596 cfs Peak Sfg:1 D327 ff Active Va1:1094.47 of h4afch Q; 0,1595 cfs Peak Ouf Q 0.1595 cfs Peak Sfg,100,68 ft Active Vo1;117.43 cf Project Prenips f2 yrl 2.70 in ilooyri 5,3oiu i6 moi 1,73 in Hydrograph ID,100 yr Out (24•hour) Area; 0,5370 ac Hyd InL 10,00 min Peak Flow; 0.1595 cfs Peak Time; 6,83 hrs Hyd Uol; 0,1969 acft Hydrograp h ID. 2 yr Out (24•hour) Rrea 0,5370 ac Hyd Int; 10,00 min Peak Flow: 0.1595 cfs Peak Time: 7.67 hrs Hyd Vol: 0,0884 acft Drainage Area; Total Site (24•hour CN) Hyd Method; SBUH Hyd Loss Method; SCS CN Number PeakFacfor: 484,00 SCSAhs; 0,20 Storm Dur .24,00 hrs tofu: 10.00 min Area CN TC Poruious 0.1850 ac BD,00 0.08 hrs Impervious 0,3520 ac 98.00 D.08 hrs To(al 0,5310 ac Supporting polo; Pervious GN Data. Landscaping 80.00 0.1850 ac Impervious CN Data; Pavement and Sidewalks 96,D0 02250 ac Building Rcof 96,00 0.1270 ac Pervious TC Data; Flowfype: Desaripfion; Length; Slope; Coeff; TTavelTime Fixed Assumo 5 min D~00 ft 0.00% 5.0000 5.00 min Impervious TC Data; Flowfype Description; Lenafh; Slope: Coeff: Travel Time :ASludroslCW~1CG~00~,C62d',,iotlays~0anlogCesignlSlorml~alcs~firalC~I~ulofio~islFnalSloimUraina~eCal~ulelio~s.tloc IIJ SformSHEDCaloulatioos Jo6Na~IP~ojeCl', U62421oday'sDea!al ~a!e:03114103 B yaJ Fixed Assume 5 min O,OD fl 0.00% S.OODO 5,00 mla Basi~iD Peak Q Peak T Peak Vol Nrea Method Raintype Event --•-•-• (cfs) (hrs) (ac•ft) ac iLoss TofalSite(24•hourCN( 0.14 500 00505 0,54 SBUNISCS TYPEIA 6mo Total Site (24-hourCN( 0.25 8.00 00883 0.54 SSUHISCS TYPE1A 2yr TotalSile(24~hourCN) 0,67 8.00 0.1972 0.64 SBUHISCS TYPE1A 100 Node ID. SformTech Start EI: 100,0000 ft i~ax EC 104.0000 ft Corltrib Basin. Coalrib Hyd; Sfago Irpul Volume Volume 100.00 0.00 cf 0.00 cf 0.0000 acfl 100.50 86.00 cf 86,00 cf D,DD20 acfl 101,00 172,00 cf 172.00 cf 0,0039 acfl 101,50 413,00 cf 413.00 cf O.D095 acfl 102D0 641,D0 cf 641,00 cf 0.0147 acfl 102.50 85D,D0 cf 850 00 cf 0.0195 acfl 103.00 103D.00 cf 1D30,00 cf 0.0236 acfl 103.50 1150,00 cf 1150,00 cf 0,0264 acfl 104.00 1236,00 cf 1236.00 cf 0.0284 acfl Storage provided by 17 SformTech chambers with 12 inches of stone base and 6 inches of stone cover Sfage•Storge Table for node SformTech Stage Vol Vol Slage Vol Vol (ft) (cf) (ac•ff) (ft) (cf) (ac-fi) 1DD.DO o.DD o,o9DD 1o2:2D 724sD o.G1s6 1GO.1D n.2o G,ooo4 162.30 tss.aD o.G1is 1DG2a 34.4D D.ooo3 1o2.4D a9a.2o o.D1aa 100.30 61,60 D~0012 102.60 860,00 0,0196 iDD~40 6x,80 0.0016 102.60 889.00 0.0203 100,50 8600 0.0020 102.70 922.00 0.0212 100,60 103,20 0.0024 1D2.80 95800 0.022D 100.70 120.40 0,0028 10290 994,00 0.0228 10080 13160 00032 10300 103000 0,0236 100.90 154.80 0,0036 103,10 1064.00 ~ 0.0242 90100 112.00 0.0039 103.20 1078.00 0,0247 101.10 22020 0.0061 1D3a0 1102.00 0.0253 10t2C 26840 O,C062 1D3.40 1126.00 D0258 101.30 316.60 0.0013 103,50 115000 D0264 101.40 364,80 0.00 10360 1167.20 0,0268 1D1.50 413,00 O.OD95 103.70 1184A0 00272 101.60 468,80 0.01D5 103.BC 1201,60 0.0276 101,70 5D4.2D 0,0116 103.9D 1218.80 0.0280 101.80 549.80 0.0126 104OD 1236.CG 0.0284 101.90 595.40 00137 102,00 641.00 0,0141 102.10 68280 0,0157 41SutlioS~,Cv,~DdCbJ10o242~iotl°ys pPnlalpeugo\,o~m\Cas'~kno!Ca.u4a~ onilrinel So~m pwi°cge Ce cu'a'~°os doc il3 t4 (y7jl n. ~"1JIM .RA.. ~Wt..C. 1rt).. S1o~mSHEDCcialal'roos JobNoJProjeC!:06242ioday'sDeofal Date: 63114 Control Structure ID. ChamberBottom • Stage Discharge rating curve Descrip Multiple Orifice Slarl EI Max EI hcremeal 100.0000 ft 104,0000 ft 0.10 kpproximafe french footprint:689,17 ft2 10 inlhr ~ 0.08333 fflin X0.0002778 hrlsec ~ 689,17 ft2 = 0,1595 cfs Sfage•DischargeTabte far control: ChamberBottom Stage Discharge Stage Discharge (fl) (Dfs) (f<) (cfs) 100.00 x1596 1o21D 0,1595 10010 6.1595 102.20 0,1595 100.20 0,1595 ~ 102,36 01695 100.30 D,1595 102,40 0.1595 100,4D 01595 102.5D 0,1595 100.50 0.1595 102.60 0.1595 100,60 0.1595 1027D 0,1595 100.10 01595 102.80 0.1595 1DD.80 01595 102,90 0.1595 1DD.90 0,1595 103,00 0.1595 iD1.00 0.1595 103,10 0.1595 10110 0.1595 10320 0.1595 101.20 0.1595 10330 0,1596 101.30 0.1696 10340 0.1696 10140 0,1595 103,50 0.1595 101.50 0,1595 103.60 D.1595 101,60 0.1595 103,10 D~1595 101,ID 01595 103.80 -01595 101.BD 0,1595 103,90 0.1595 101.9D 0.1595 1040 0.1595 1D2,00 01595 X.`,S!utlic~~Cin1~,06p~1~b~e2 rode Deo~ol~,De~g~~~Storm~CaleslF,na! Ca',a~ allorslfiooi Sb~m Cmioaye Colcu;albos.~oc o;++~ Number a(Chamber in Bed ~ 17 Volum:aoluoltlsialhuslaoa~ 6,30 ~~~~~~~~, ttNRka.°c'r~'m~w4,p, Subswlace $!Ofn111'aL^f Pdaoapomao!" StormTech SC 140 Incremental Storage Volumes Heighfof Cumu!aliue TolalSyslem Sysfem(ia~ Chamher(f131 Slaraaaffl~I SlomeefifBl Vnlume Iflal 48 0 0.85 72,73 1236 ~47 6 0.85 71,89 1222 i 46 0 0,85 71.04 1208 45 6 0.85 7020 1193 44 0 0.65 69.35 1179 43 0 0.65 68,51 1165 42 0,05 O.B6 67.66 "150 4", 0.16 096 66.78 1135 40 026 1,04 65.82 1119 39 0.60 1,27 fi4.77 1101 38 0.80 1.41 6351 1080 37 0.95 iS1 62.10 1056 36 1.07 1.60 60.59 1030 35 t18 1.67 5899 1003 34 127 1.73 57,32 974 33 1,36 1.19 55,59 945 32 1A5 1.86 53.80 915 31 1,62 1,91 5193 883 30 1.56 1.95 50.02 850 29 1.64 1.99 49,01 617 28 1.70 2.03 46,07 783 27 1.75 2.07 4404 749 2fi 1,80 2,11 41.97 113 25 1.85 2,14 39.86 676 24 1.89 2.17 37.12 641 23 1.93 2.20 35,55 604 22 191 2.23 33.35 567 21 2,01 225 31.12 529 20 2,04" 2,28 28.87 491 19 2,07 2,30 26,59 452 18 2.10 2,32 2429 413 17 293 2.34 21.97 314 16 2.15 235 19,64 334 15 2,18 2.37 17.28 294 14 2.20 2.38 14,92 254 13 12 2.21 0 2.39 O BS 12.63 10 14 213 11 0 . 0,85 . 9,30 172 158 1D 0 0.86 8A5 144 9 0 0.85 7,61 129 B 0 G.85 6.76 115 1 0 0.85 5.92 101 6 0 0,85 5,01 86 5 0 0.85 423 12 4 0 0.85 3.38 57 3 D 0.85 2,54 43 2 0 ~ 0.85 1.69 29 1 0 0,85 0.85 14 I1,l3 TotalChamBarStorage= 45,9fl' Calou!alloas2re Bawd upon a 12'moh slope bzse undertha aiamBe~a a ~~ S!amSHEDCaicu!ai'oos JobNo.IP~ojocf 062a2 CONVEYANCE CALCULATIONS Manning Pipe Calculator Given Input Data; Shape ,,,,,,,,,,,,,,,,,,,,,,,,,,, Circular Salving for ..................... Depth of Flow Diameter ,,,,,,,,,,,,,,,,,,,,,,,, 0,6667 ft Flowrate ,,,,,,,,,,,,,,,,,,,,,,,, 0,5700 cfs Slope ,,,,,,,,,,,,,,,,,,,,,,,,,,, 0,0100 ftlft Morning's n ,,,,,,,,,,,,,,,,,,,,, 0.0130 Dpfe: Computed Results; Depth ........................... 0.3722 ft Area ,,,,,,,,,,,,,,,,,,,,,,,,,,,, 0,3491 ft2 Wetted Area ,,,,,,,,,,,,,,,,,,, ,, 0,1671 ft2 Wetted Perimeter ............. ... 1,0249 ft Perimeter ,,,,,,,,,,,,,,,,,,,,,,, 2,0945 ft Velocity ,,,,,,,,,,,,,,,,,,,,,,,, 3A114 fps Hydraulic Radius ,,,,,,,,,,,,,,, , 0,1630 ft Percent Full ,,,,,,,,,,,,,,,,,,,, 48,3208 io •••~•~> pipe is only 59.2% full during Full flow Flowrate ,,,,,,,,,,,,,, Full flow velocity ,,,,,,,,,,,,,, 3,4620 fps Critical Information Critical depth ,,,,,,,,,,,,,,,,,, 0,3545 ft Critical slope ,,,,,,,,,,,,,,,,,, 0,0072 ftlft Critical velocity ,,,,,,,,,,,,,,, 3.0214 fps Critical area ,,,,,,,,,,,,,,,,,,, 0,1887 ft2 Critical perimetor ,,,,,,,,,,,,,, 1,089b ft Critical hydraulic radius .,,,,,, 0.1731 ft Critical tap width ,,,,,,,,,,,,,, O.b667 ft Specific energy ................. 0,5030 ft Minimum onergy ,,,,,,,,,,,,,,,, ,, 0,5318 ft Fraudenumber,,,,,,,,,,,,,,,,,, , 1.2010 Flow condition ,,,,,,,,,,,,,,,,,, Supercritical 100•year, 24~hour design event 1.2086 cfs ~~~~~•> Pipo capacity exceeds 100-year, 24~hour design overt maximum flowrate (0,57 cfs) Xi~SlutlloslClvi11e60001062a2dotl~ys. ?onlall-efigii\Slam~ACalcs\&n~l Calculaliors~,Comeyon~e Co cu ~7~'00=. tloc APPENDIX E WATER QUALITY CALCULATfONS ._~_w.~~'4.A ~yn :C:wi ...3f Ai ~ ` fi 1 ; V ~ ~ ~ ..A Z~ ~ h ~ .:. )~.. . V ' `:~i S1ormSHED Calculations fob No./Project p6242 Today's #]ente! WATER QUALITY CALCULATIONS Water Quality Event Summary: BasinlD Peak Q Peak T Peak Vol Area ------- {cfs) {hrs) {ac-ft) ac Water Quality 0.17 8.00 0.0404 0.41 larainage Area: Water Quality Hyd Method: SBUH Hyd Loss Method Peak Factor: 484.00 SC5 Abs: Storm Dur: 24.00 hrs inty: Area CN TC Pervious 0.1$50 ac 80.00 0.08 hrs Impervious 0.2250 ac 98.fl0 0.08 hrs Total 0.410fl ac Supporting Data: Pervious CN Data: Landscaping 80.00 0.1850 ac Impervious CN Data: Pavement and Sidewalks 98.00 0.2250 ac Pervious TC Data: Flow type: Description; Length: Fixed Assume 5 min 0.00 ft Impervious TC Data: Flow type: Description: Length: Fixed Assume 5 min 0.00 ft 0.00% 5.0000 5.00 min Qw9. Peak - 0. ~ ~ CfS Use 27" tal€ cartridges with flowrate of 22. 5 gpm 449 gI?r~z cfs = 2.20 Nearrrldges = 0.1 Icfs • 22. S - g~rn _..... cartidge Use 3 StormFi€ter® cartridges Method /Loss SBUH/SCS SCS CN Number a.2o 10.00 min Daie: Raintype Event TYPEIA 6 mo 5€ope: Coeff: Travel Time 0.00% 5.0000 5.00 min Slope: Coeff: Travel Time X:\St~Uios\Civii\Ob00D\Ofi242-TOdoys_Denla!\Design\Slorm\Colcs\rinpl GOICUlptlOnS\FinpE Wp4er Q~oiily COICiS3o1ion5.doC 3 / I STORM WATE=R SOLUTIONS INC. Prepared by Christina Tatland on May 19, 2008 Size and Cost Estimate Today's Dental _Stormwater Treatment System Yelm, WA Information provided; • Total contributing area = 0.43 acre • Impervious area ~ 0.225 acre • Water quality flow, Qwq = 0.11 cfs • Presiding agency =City of Yelm Assumptions: • Media ~ ZPG cartridges • Drop required from inle# to outlet = 3.05' minimum Size and cost estimates: The StormFilter is a flow-based system, and therefore, is sized by calculating the peak water quality flow rate associated with the design storm. The water quality flow rate was calculated by using SBUH and provided to CONTECH Stormwater Solutions Inc. The StormFilter for this site was sized based on a water quality flow rate of 0.11 cfs. To accommodate this flow rate, CONTECH Stormwater Solutions recommends using a 48" Manhole StormFilter with 3 cartridges (see attached detail). The estimated cost of this system is complete and delivered to the job site. This estimate assumes that the vaul# is S feet deep. The final system cost will depend on the actual depth of the units and whether ex#ras like doors rather than castings are specified. The contractor is responsible for setting the StormFilter and all external plumbing. Typically the precast StormFilters have internal bypass capacities of 1.8 cfs. if the peak discharge off the site is expected to exceed this rate, we recommend placing ahigh-flow bypass upstream of the StormFilter system. CONTECH Stormwater Solutions could provide our high-flow bypass, the StormGate, which provides a combination weir-orifice control structure to limit the flow to the StormFilter. The estimated cost of this structure is $4,000. The final cost would depend on the actual depth and size of the unit. ©2006 CONTECH Stormwater Solutions 12029-[3 NE Airport Way, Portland OR 97220 Page 1 of 2 contechstormwater.com Toll-free: 800.548.4887 Fax: 800.581.1271 TS-P027 APPENDIX F OPERATIONS AND MAINTENANCE MANUAL 9 Maintenance Plan Introduction/Project Description The site starmwater management facility consists of a storm drain conveyance system for a new dental office building and adjacent parking lot. A conveyance system will collect runoff from the asphalt pavement and building roof. Treatment of the runoff from the asphalt parking area will be accomplished by routing it through a manhole that contains three Starmfilter® cartridges. It will then be routed to a single underground Stormtech®infiltration basin. The runoff from the building roof will bypass the treatment manhole and flow directly to the Stormtech®system. The on-site storm system will require regular maintenance. Inspection of the conveyance system should take place following any significant storm events. If leaves and other debris have accumulated at the catch basin grates, they should be removed. Annual maintenance of the Contech Stormfilte~ and Stormtech® system are required. See Attachment "C" and Attachment "D" for the respective maintenance manuals. Also, sediment should be periodically vacuumed out of the catch basin sumps. The property owner will be responsible far maintenance of the storm drainage system. The Operations and Maintenance Manual must be kept on site. The attached checklists indicate maintenance actions that must be performed in order to keep the system functioning properly. Maintenance Schedule The detailed maintenance schedule is shown in Attachment "A" of this plan. It should be closely followed to keep the system functioning properly. Additional maintenance may be required as a response to unusual storm events. Estimated Cost The estimated annual cost for maintaining the conveyance system is shown below. It includes costs associated with debris removal, pipe cleaning, and catch basin cleaning. The casts are simply and estimate. They should be revised after construction is complete. Maintaining vegetation Personnel C~ $25/hour for 30 hours $750 Pipe and catch basin cleaning Personnel and vacuum truck C $900/hour for 6 hours $600 Cleaning Stormtech®system Personnel and vacuum truck C~ $900/hour for 3 hours $300 Cleaning/Replacing Storfilter® cartridges $205/cartridge for 3 cartridges $615 $2,265 STORMWATER ~'~~-- SO~UTIONSttvc. Prepared by Christina Totland on May 79, 2008 Size and Cost Estimate Today's Den#al -Stormwater Treatment System Yelm, WA tnfarmation provided: • Total con#ributing area = 0.43 acre • Impervious area = 0.225 acre • Water quality flaw, Owq ~ 0,11 cfs • Presiding agency =City of Yelm Assurttptions: • Media = ZPG cartridges • Drop required from inlet to outlet - 3.05' minimum Size and cost estimates: The StormFilter is a flow-based system, and therefore, is sized by calculating the peak water quality flow rate associated with the design storm. The water quality flow rate was calcu€ated by using SBUH and provided to CONTBCH Stormwater Solutions Inc. The StormFilter for this site was sized based an a water quality flow rate of 0.11 cfs. To accommoda#e this flow rate, CONTECH Stormwater Solutions recommends using a 48" Manhole StormFilter with 3 cartridges (see attached detail). The estimated cost of this system is complete and delivered to the job site. This estimate assumes that the vault is 6 feet deep. The fnal system cost will depend on the actual depth of the units and whether extras like doors rather than castings are specified. The contractor is responsible for setting the StormFilter and all external plumbing. Typically the precast StarmFilters have internal bypass capacities of 1.8 cfs. [f the peak discharge ofF the site is expected to exceed this rate, we recommend placing ahigh-flow bypass upstream of the StormFilter system. CONTECH Stormwater Solutions could provide our high-flow bypass, the StormGate, which provides a combination weir-orifice control structure to limit the flow to the StormFilter. The estimated cost of this structure is $4,000. The final cost would depend on the actual depth and size of the unit, 02006 CONTECt-{ Stormwater Solutions 12021-8 NE Airport Way, Portland OR 97220 Page 1 of 2 contectistom3water.c°m Toll-tree: 800.548.4667 Fax: 800.569.1271 TS-P027 Attachment "A" Inspection Period: Maintenance program Cover Sheet Number of Sheets Attached: Date Inspected: Name of Inspector: Inspector's Signature: Instructions for Use of Maintenance Checklists The following pages contain maintenance requirements for most of the components that are part of your drainage system. It also contains requirements for some components that you may not have. Ignore any requirements that do not apply to your system. Let the County know if there are any components that are missing from these pages. You should plan an completing a checklist for all system components on the following schedule: (1) Monthly from November through April (2) Once in late summer (preferably September) (3) After any major stiorm (use 1-inch in 24 hours as a guideline) Make photocopies of these pages and check off the problems you looked for each time you made an inspection. Add comments regarding problems found and actions taken. Keep these "checked" sheets in your files because they will be used to write your annual report. No. 2 _ lnfif~ration ~"`'3'~~~.~(.~'in~Y ~/~~t~N,s~a~'~~,~ p~o .~ `?~I.-:~~(„p,~*, ~'f yY~`~~~5 "af~s ti ;'+"~"w,i,."ie.}`~~4~i~-<4 ..)YE:~~,[e-.\I,G.-7~-~~'x~~"~~'fEZ4..,33~ 'F.~3v,3ei~fh~ ~' FY . fi"'s. e ~`~ ~ ~, q ~1 ~' ~ `~~ ~ s/4'.~i t~,~sy;~.C -;n, .~3, `~ :e z.~{war M~i?y~s;•~,,~ ~~"~ia~l ,~,i/r a t~ : 3 jsS}, 434~~~\A~~Qr1.4,2 P..~~„1~~{~W~fa11~}iq 4~`'~ S.rUgi\`i M~ ? :.5:'+ z~` ~~= 5 `iL~ ~< ~~~7 ~ ~~~G{~~'~* ~`~ ~ ~ ~ , ~ . ~~}: ~~i+(7 ~{F~~v. .~~';;`-'.~~`., 1~ ~ti ,. ~„~ ~~\ei1~~Lwlf~~.~.~j~d~~Ch~n- 3 i - ' M \ ,.~;E,. ~ Y 9.ti ,?. L .,., y~ ~~1 ~~~1 ~ ```~~ ~ ~ ~~ ' ~~`. , ~<., tisw ~~~e, ~.< ,.4r~~>~ ~'„~~ ~, , , rt, y-,r1^"~ .~,, i ~~~'sv ;y~~~~.. ~.. L .. ~ s r, i 'S; 'W~ 3Y z's ' `t` ~g; ~ ~ . ' ~ ~( ~ ~ ~~ ~ t ~ ,~~us ~,~c~Y, ~..,~,-a= <",x * r~a .; +'~_ C ~,Z,ss'~`5~~,~.~;~+~.~y £~'~~`;ir~y I ~~~ ~ ~~._ai~ .t,;1"~$ ~,'~~53 e ~';~~:~ ~~r~~ l z _" , r c~ '' ' ~~c''x3C '~ ~S` ~ ~ ; ' y ~ ~R~ S r ~ ;~~p ' a `~ ~' ~r i~~Y '~ r c,:- .~~s~~~';5,~` e'~`~~: i~${~r'~ ~LI3q 1Y~€ b S ~,: ~ . ~. ,. . ±5 ~~`:-s T~ . i . ,< F f.~a .. a'_a 'n, ~%s~, .~ka~'/ h?s~.., n,._.i~, , ~>. ~ ~: 'i. y "t 4 1v 4Q` E . `1j - ~ ~ ~6 z~`iT S~ar~.3a $..-: C.%.. c4 _..ki, .y'.,. 'd~ "y; . ,.. ..lvfa:5 g ~~t. t ,..3~'L General Trash & Debris See "Detention Ponds" (No. 1}. See "Detention Ponds" (No. 1). PoisonousMoxiaus See "Detention Ponds" (No. 1). See "Deters#ian Panels" Vegetation (No. 1). Contaminants and See "befention Panels" (No. 1). See "Defentian Ponds" Pollution (No. 1). Rodent Holes See "De#enfion Ponds" (No. 1). See "Detention Ponds" {Na. 1) Storage Area Sediment Water ponding in infii#ra#ion pond after Sediment is removed rainfall ceases and appropriate time andlor facility is cleaned allowed for infii#ration. so that infiltration system Forks according to A ereofation test it or fest of faeili# ( p p y design. indicates facility is only working at 90% of its designed capabili#ies. if #wo inches or more sediment is present, remove}. Fiiter Sags (if Filled with Sedimen# and debris fill bag more than 112 Filter bag is replaced ar applicable} Sed'smenf and full. system is redesigned. Debris Rock Filters Sediment and By visual inspection, little nr nn water flows Gravel in rock filter is Debris fhrough filter during heavy rain storms. replaced. Side Slopes of Erosion Sea "Detention Ponds" (No. 1). See "Deters#ion Ponds" Panel (No. 1). Emergency Tree Growth See "Defentian Panels" (No. 1). See "Detention Ponds" Overflow Spil Iway (No. 1). and Berms over A , feet in height. Piping See "Deters#ian Ponds" (No. 1). See "Detention Ponds" (No. 1). Emergency Ronk Miss'sng See "Detention Ponds" (No. 1). See "De#ention Panels" Overflow Spillway ~ (No. 1). Erosion See "Detention Ponds" (No. 1). See "Detention Ponds" {No. 1). Pre-settling Facilityor sump , B" ar designed sediment trap depth of Sediment is removed. Ponds and Vaults rifled with Sediment sediment. andlor debris tg ,F a~L!: Vv.++~: February 2005 Volume V -Runoff Treatment BMPs 433 No. 5 -- Catch Basins General ~y,~ 9h ~ I' k~ +n G ~'. '. ~ Cf~~ ~4'ks~kS 'y"'~Ytil~' ~d 1~yY~ ti.$'§'"44 f- ~ - ~E k A 'W 3 ~f3~ ~i~Ur~}~s~Br~~a~~~~' ~ 0~H F9?EB~~~d ~~ ~ ~ `^y~ y ~ .~a" rte' ,_~,} ,fit ~h_"~ ~~~If~~X~~ii~ VS~~*~, ~~~, 11 ~ i . ~ ' P ~ ~ti ~~ r 3, t~'? ~ ~ ` ~ ~ ~~ ~ ~ ~ ~~~ ~ ~ Y Qt'fI1C~i>~ 3 ~i' ~ 4~ ~~x~~ ~ 2 ~ ~ 3. ' " f~l -. ..- .. .. i r: ~Yi30.!a„ f 4t ~.'l kA7 i(~~.., 4~ ~14.' .~.3 , Sl~: [`~ ~..~ ~ .~.~~ ~ ~ T 3 4 n . ~i ~n..,. Trash & Trash or debris which is located immediately No Trash or debris located 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 grafe 'mare than 10%. opening. Trash ar 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 minirrium of six inches clearance from the debris surface to the invert of the lowest pipe. Trash or debris in any inlet or autlet pipe Inlet and outlet pipes free blocking more than 113 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 within or dangerous gases (e.g., methane). the catch basin. Sediment Sediment (in the basin) that exceeds 80 No sediment in the catch percent of the sump depth as measured from basin the bottam of basin to invert of the lowest pipe into or aut of the basin, but in no case less than a minimum of 6 inches clearance from the sed'€ment surface to the invert of the lowest pipe. Structure Top slab has holes larger than.2 square Top slab is #ree of holes Damage to inches or cracks wider than 114 inch and cracks. Frame andlor Top Slab (intent is to make sure no material is running into basin}. Frame not sitting flush on top slab, l.e., Frame is sitting flush~on separation of more than 314 inch of-the frame the riser rings or top slab from the top stab. Frame not securely and flrrnly atkached. attached Fractures or Maintenance person judges that structure is Basin replaced or repaired Cracks in unsound. to design standards. Basin Wallsl Bot#am Grout fiAet has separated or cracked wider Pipe is regrouted and than 712 inch and IongEr than 1 fact of the secure at basin wall. joint of any inlet/outlet pipe or any evidence of soil particles entering catch basin through cracks. Settlement/ If failure of basin has created a safety, Bash? replaced or.repaired Misalignment function, or design problem. to .design standards. Vegetation Vegetation growing across and blocking more No vegetation blocking than 70% of the basin opening. opening to.basin. Vegetation growing in inlet/outlet pipe joints No vegetafion ar root that is ,more than six inches tat) and less than growth present. six inches apart. "~.. 4-36 Volume V ~- Runoff Treatment BMPs February 2005 No. 5 -Catch Basins s F.~k^.~`~s a~ ~' ~~ ~ ~e~a ~ '~.~~~ ' ~'P~ ,~. ~ ~a ~ D e ~ .P~*' #, t ~ ' ~v`. ~""a~~ ~ ~~w'"~u',S ~ `~ ~t~'' i~~~ '~ ~ arr ro s~ e a u~e~s} eed d ~ , ~ ~ dl. ~~'~ k s'~ yti~~~#~ s~~~p~G' °M..~v"P Resifs e~e~ e ~'ai~te ~~"~' gas ~~ - -,a_. f . K ~ ;y `.si' ,f. ~.tY`~.`,w e%c, :i ~ ~'' ~ ^.2°~,$2'~`,c1^,'r`dlG. ,.t?,~~4 Con#aminafion See "Deters#ion Ponds" (No. 9). No pollution present, and Po€lution Catch Basin Cover Not in Cover is missing or only partially 'sn place. Catch basin cover is Cover Place Any open catch basin requires mainfenarice. closed Locking Mechanism cannot be opened by one Mechanism opens with Mechanism maintenance person with proper tools: Batts proper tools. Not Working into frame have less than 1Y2 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 at#ad-red to basin wall,. standards and allows misalignment, rust, c~aaks, ar sharp edges. maintenance person safe access. -Metal Grates Grate opening Grata with opening wider than 718 inch. Grate apenfng masts (If Applicable) Unsafe design stAl~dat'tis. Trash and Trash and debris that is biockin~ mat's than Gttp frr3e ditraah r~n~ Debris ?t)% of grate r3urfa~e iniading capacity, d~&. Damaged ar Grate missing car broken member(s) of the Qr~;~ l~ ifi ~~ Missing. grata. ~~~ ~~ ~ ~ ~ ~ ~ _~; , ~, ,,: , February 2f~05 Volume V -Runoff Troafinenf BMAs 4.37' No. 15 - StormfilterT"' (leaf compost fil~:r) s ~e>,~y ,~,'y .. °~ r ~~~~ ` te? "L ~-YSaC~~~, _ b~c ~' _~ w ~i~ ~[ .s"bS;.~-',~^`~m,.3,~ t`~P ~'Frs .~}~, ~^~, s- s e.£.,~ rY""~~r~ kt``~,s~, -` X5' ~~I~~ICJp~~'.~~j,-`~7Yf~~~t•~~~1~~~.~~.5' ~ r cY o ~ r i~ fi `^~ ~- 4 ~ ~' -Y" ~i 3 akY:'~£. a,~.r{,-,'., .Kd.' ~(~~'s`'*. ~_~' ~.*SL.s a.°. „ ~ ,a-;. c~ PjS~~k~~,~.f'~~it~~ i~ 7~ ,- "Lis v.~l~~ a ~?"E'~.`~~~e ` ~ / r ~'} g }~ ,. Q ~ ~ c e.. 3~°`° c , e ~ ~~k ~ < ~~~~ ~~ ~ ~ .. , atn j7ar~CQ ~i~ ~' 1'~~ ~ ~ xa ~ sr'i"""~~~-.. L ~t i~F. ., ;&~. .. .~. x„ ~e , , 7a1~.Y,,,.,^.~t...-:3:(.,,~['f,~''aS.,~-a..'Zax ti~v...,, 3~n.:x'~G;cr ~~~Yr.~,., t~ ." ~` .~a~,S;YKS~'n"'ItCiSt.~;'A'_`3's.z~. ~?..; Below Ground Sediment Sediment depth exceeds 0.25-inches. Na sediment deposits which Vault Accumulation on would impede permeability of Media. the compost media. Sediment Sediment depth exceeds 8-inches in first No sedimenf deposits in vault Accumulation in chamber. bottom of first chamber. Vault Trash/Debris Trash and debris accumulated on Trash and debris removed #rom Accumulation compost filter bed. the compost filter bed, Sediment in When drain pipes, clean-outs, become Sediment and debris removed. Drain full with sediment andlor debris. Pipes/Clean- Outs Damaged Pipes Any part of the pipes that are crushed or Pipe repaired andlor replaced. damaged due to corrosion and/or settlement. Access Cover Cover cannot be opened; one person Cover repaired #o proper DamagedlNot cannot open the cover using normal working specifications ar Working lifting pressure, corrosionldeformation of replaced. cover. Vault Structure Cracks wider than 112-inch or evidence Vault replaced or repairs made fncfudes Cracks of soil particles entering the structure so that vaul# meets design in Walf, Bottom, through the cracks, or speaficatians and is structurally Damage to maintenance~nspectian personnel sound. Frame andlor determine that the vault is not structurally Top Siab sound. Cracks wider than 112-inch at the joint of Vault repaired so that na cracks any inletloutfef pipe or evidence of soil exist wider than 1/Ranch at the particles entering #hrough the cracks, joint of the inletloutlet pipe. Baffles Baffles corroding, cracking warping, Baffles repaired nr replaced to andlor sho~nring signs of failure as specifications. determined by maintenancefinspecfion person. Access Ladder Ladder is corroded or deteriorated, net Ladderreplaced or repaired and Damaged functioning properly, not securely meets specitcations, and is attached to structure wall, missing rungs, safe to-use as determined by cracks, and misaligned. inspection personnel. Below Grcaunii Compost Media Drawdown of water through the media Media cartridges replaced. Car ridge Type takes longer than 1 hour, andlor overflow occurs frequently. Short Circuiting Flows do riot properly enter filter Filter cartridges replaced. cartridges. ~.. t:s.~ February 2005 Volume V -Runoff Treatment BMPs 4-47 Attachment "~" Pollution Source Control Program Pollution source control is the application of pollution prevention practices to prevent contamination of starmwater runoff. The applicant/owner shall be responsible far controlling potential pollutants at their point of use ar generation. The plan of action will include elements such as centralized area for storage of equipment, lubricants, pesticides, etc. The owner may elect to follow the detailed guidance on control of non-sediment pollutants as outlined in the DOE Manual. The most important practice is to ensure that no hazardous wastes, such as oil, shall be dumped into the storm drainage system. "Dump Na Waste" shall be stenciled near each catch basin. The relevant pollution control section from the DOE manual is included as part of this attachment and is an integral part of the plan. BMPs for Description of Pollutant Sources: Landscaping can include grading, soil Landscaping transfer, vegetation renroval, pesticide and fertilizer applications, and and Lawrtl watering. Stornawater contaminants include toxic organic compounds, Vegetation heavy metals, oils, fatal suspended solids, colifonn bacteria, fe~'tilizers, and Management pesticides. Lawn and vegetation management can include control of objectionable weeds, insects, mold, bacteria and other pests with cheinicaI pesticides a~~d is conducted commercially at co~nanercial, industrial, and residential sites. Exatnples include weed coa~trol on golf course lawns; access roads, and utility corridors and during landscaping; sap stain and insect control on lumber and logs; rooP:op moss removal; killing nuisance rodents; fungicide application to patio decks, and residential lawn/plant care. Topic pesticides such as pentachlorophenoI, carbamates, and organometallics can be released to the enviranmerit by leaching and dripping from treated parts, contauier leaks, product misuse, and outside storage of pesticide contaminated materials and equipment. Poor management of the vegetation and poor application of pesticides or fertilizers can cause appreciable storinwater contamination. Pollutant Coaatrol Approach: Control of fertilizer and pesticide- . applications, soil erosion, and site debris to prevent contamination of stormwater. Develop and irnplexnent an Integrated Pest Management Plan (IPM) and use pesticides only as a last resort. If pesticides herbicides are used they must be carefully applied in accordance with label instructions on U.S. Environmental Protection Agency (EPA) registered materials. Maintain . appropriate vegetation, with proper fertilizer application where practicable, to control erasion and the discharge of stormwater pollutants. Where practicable grow plant species appropriate for the site, or adjust the soil properties of the subject site to grow desired plant species. .Applicable Operational BMPs foz• Lau.dscaping: • Install engineered soillIandscape systems to improve the infiltration and regulation of stormwater in landscaped areas. • Do not dispose of collected vegetation into waterways or storm drainage systems. Recommended Additio~tal Operational BNII's for Landscaping: • Conduct mulch-mowing whenever practicable Dispose of grass clippings, leaves, sticks, or other collected vegetation, r~.. by composting, if feasible. February 2005 Volume !V -Source Control BMPs 2-23 • Use mulch or other erosion control measures when soils are exposed for more than one week during the dry season or two days during the rainy season. • If oil or other chemicals are handled, store and z~aintain appropriate ail and chemical spill cleanup materials in readily accessible locations. Insure that employees are familiar with proper spill oleanup procedures. • Tiil fertilizers into the soil rather than dumping or broadcasting onta the surface. Determine the proper fertilizer application for the types of soil and vegetation encountered. • Till a topsail mix or composted organic material into the soil to create a well-mixed transition Iayer that encourages deeper root systems and drought-resistant plants. • Use manual and/or mechanical methods of vegetation removal rather than applying herbicides, where practical. Applicable Operatiozzal BMPs for the Use of Pesticides: • Develop and implement an IPM (See section on IPM at end of BMP} and use pesticides only as a last resort. • Implement a pesticide-use plan and include at a minimum: a list of selected pesticides and their specific uses; brands, formulations, ~~ application methods and quantities to be used; equipment use and maintenance procedures; safety, storage, and disposal znetl~ods; and monitoring, record keeping, and public notice procedures. All procedures shall conform to the requirements of Chapter 17.21 RCW and Chapter I6-228 WAC (Appendix IV-D R.7). Choose the least toxic pesticide available that is capable of reducing the infestation to acceptable levels. The pesticide should readily degrade in the environment and/or have properties that strongly bind it to' the soil. Any pest control used should be conducted at the life stage when the pest is most vulnerable. Ijor example, if it is.necessary to use a Bacillus thurin -leg ns is application to control tent caterpillars, it must be applied before the caterpillars cocoon or it will be ineffective. Any method used should be site-specific and not used wholesale over a wide area. • Apply the pesticide according to Iabel directions. Under no conditions shall pesticides be applied in quantities that exceed manufacturer's instructions. • Nizx tlae pesticides and clean the application equipment in~ an area where accidental spills will not enter surface or ground waters, and will not contaminate the soil. ~~~ ~, , 2-24 Volume !V -Source Confrol BMPs February 2005 ~, Store pesticides in enclosed areas or in covered iinpeivious containzxzent. Ensure that pesticide contaznitrated storzz~zwatez• or spills/leaks of pesticides are not discharged to storm drains. Do not hose down the paved areas to a storm drain or conveyance ditch. Store and maintain appropriate spill cleanup materials in a location known to all near file storage area. • Clean up any spilled pesticides and ensure that the pesticide contaminated waste materials are kept in designated covered and contained areas. • The pesticide application ecluipznent must be capable of immediate shutoff in the event of azz emergency. • Do not spray pesticides within 100 feet of open waters including wetlands, ponds, and streams, sloughs and any drainage ditch or channel that Ieads to open water except when approved by Ecology or ,the local jurisdiction. All sensitive areas including wells, creeks and wetlands must be flagged prior to spraying. • As reeluired by the local government or by Ecology, complete public posting of the area to be sprayed prior to the application. • Spray applications should only 'be conducted during weather conditions as specified in the label direction and applicable local and ,, state regulations. Do not apply during rain or immediately before ,expected rain. Recommended Additional 4peratiorial I3MPs for the use of pesticides; • Consider alternatives to the use ofpesticides such as covering or harvesting weeds, substitute vegetative growth, and manual weed control/moss removal. • Consider the use of soil amendments, such as compost, that are known to control some eozxzmon diseases in plants, such as Pythium root rot, ashy stem blight, acid parasitic nematodes. The following are three possible mechanisms for disease control by compost addition (USEPA Publication 530-F-9-044): 1. Successful competition for nutrients by antibiotic production; 2• Successful predation against pathogens by beneficial microorganiszxi; and 3. Activation ofdisease-resistant gems in plants by composts. Installing an arraended soil/landscape system can preserve both the plant system and the soil system more effectively. This type of approach ~rrovides a soil/landscape system tivith adequate depth, permeability, and organic matter to sustain itself and continue zvarking as an effective ~ stbtmivater infiltr°ation system and a sustainable nutrient cycle. February 20Q5 Volume !V -Source Control BMPs 2-25 ~ Once a pesticide is applied, its effectiveness should be evaluated for possible improvement. Records should be kept showing the applicability and 'inapplicability of the pesticides considered. An annual evaluation procedure should be developed 'including a review of the effectiveness of pesticide applications, impact on buffers and sensitive areas {including potable wells), public concerns, and recent toxicological information on pesticides used/proposed for use. if individual or public potable wells are located iia the proximity of coininercial pesticide applications contact the regional Ecology hydrogeologist to determine if additional pesticide application control measures ai~e necessary. • Rinseate from equipment cleaning and/ortriple-rinsing of pesticide containers should be used as product or recycled into product. • The application equipment used should be capable of immediate shutoff in the event of an emergency. For• mop°e information, contact the WSU Extension Home-Assist Program, (25.x) 44.5-45.56, or Bio-Integral Resource Center (BIRC), P.O. Box 74.14, Berkeley, CA. 94707, of° the Washington Department of Ecology to obtain "Hazardous Waste Pesticides" (Publication #89-4I); and/oY EPA to obtain a publication entitled "Suspended, Canceled and Restricted Pesticides" tivhich lists all restricted pesticides arzd the specific uses that aj°e allowed. Valuable information front these sources may also be availaUle on the Internet. Applicable Operational BMPs for Vcgetation Maz~agc~a~en~t: Use at least an eight-inch "topsoil" layer with at Ieast 8 percent organic matter to provide a Buff dent vegetation-growing medium. Amending existing landscapes and turf systems by increasing the percent organic matter and depth of topsoil can substantially improve the permeability. of the soil, the disease and drought resistance of the vegetation, and reduce fertilizer demand. This reduces the demand for fertilizers, herbicides, and pesticides. Organic matter is the least water-soluble form of nutrients that can be added to the soil. Composted organic matter generally rdleases only between 2 acid l0 percent of its total nitrogen annually, and this release corresponds closely to the plant growth cycle. If natural plant debris and mulch are returned to the soil, this system can continue recycling nutrients indefinitely. Select the appropriate turfgrass mixture for your climate and soil type. Certain tall fescues and rye grasses resist insect attack because the symbiotic endophytic fungi found naturally in their tissues repel or kill common leaf and stem-eating lawn insects. They do not, however, repel root-feeding lawn pests such as Crane p'ly larvae, and are toxic to ruminants such as cattle and sheep. The fungus causes no known ..~i 2-26 Volume !V -Source Control BMPs February 2005 adverse effects to tl"ze Bost plant or to humans. Ez~dophytic grasses are commercially available azid ca~~. be used in areas such as parks or golf courses where grazing does not occur. The local Cooperative Extension of#`zce can offer advice an which types of grass are best suited to the area and soil type. Use the following seeding and planting BMPs, or equivalent BMPs to obtain information on grass mixtures, tempot•ary and permanent seeding procedures, maintenance of a recently planted area, and fertilizer application rates: Temporary Seeding, Mulching and Matting, Clear Plastic Covering, Permanent Seeding and PIanting, and Sodding as described in Volume lI}. Selection of desired plant species can be made by adjusting the soil properties of the subject site. lior example, a constructed wetland can be designed to resist the invasion of reed canary grass by layering specific strata of organic zxzatters (e.g., coFnpost forest product residuals} and creating a mildly acidic pH and carbon-rich soil medium. Consult a soil restoration specialist for site-specific conditions. Aerate lawns regularly in areas of heavy use where the soil tends to become compacted. Aeration should be conducted while- the grasses in the lawn are growing most vigorously. Remove layers of thatch '~ greater than 3/4-inch deep. • Mowing is astress-creating activity for turfgrass. When grass is mowed too short its productivity is decreased and there is less growth of roots and rhizomes. The turf becomes less tolerant of envirorunental stresses, more disease prone and more reliant on outside means such as pesticides, fertilizers and irrigation to remain healthy. Set the rz~owing height at the highest acceptable Ievel and znow at times and intervals designed to minimize stress on the turf. Generally mowing only 1/3 of the grass blade height will prevent stressing the turf. Ir•rigatiar:: • The depth frorn which a plant normally extracts water depends on the rooting depth of the plant. Appropriately irrigated lawn grasses normally root in the tap 6 to 12 inches of soil; lawns irrigated on a daily basis often root only in the top 1 inch of soil. ;_rnproper irrigation " can encourage pest problems, Ieach nutrients, and make a lawn completely dependent on artificial watering. The amount of water applied depends on the normal rooting depth of the turfgrass species used, the available water holding capacity of the soil, and the efficiency of the irrigation system. Consult with the local water utility, Conservation District, or Cooperative Extension office to help ~~1'! determine optimum irrigation practices. February 2005 Volume IV -Source Control SMPs 2-27 Fer•tilize~ Managet~rent: • Turfgrass is most responsive to nitrogen fertilization, followed by potassium anal phosphorus. Feztilization needs vary by site depending on plant, soil and climatic conditio~~s. Evaluation. of soil nutrient levels through regular testing ensures the best possible efficiency and economy of fezfilization. For details on soils testing, contact the local Conservation Distz•ict or Cooperative Extension Service. Fertilizers should be applied in amounts appropriate for the target vegetation az~d at the tune of year that minimizes losses to surface and ground waters. Do not fertilize during a drought oz• when the soil is dry. Alternatively, do not apply fertilizers within three days prior to predicted rainfall. The longer the period between fertilizer application and either rainfall or irrigation, the less fertilizer runoff occurs. Use slow release fertilizers such as methylene urea, IDBU, or resin coated fertilizers when appropriate, generally in the spring. Use of slow release fertilizers is especially important in areas with sandy or gravelly soils. • Tinle the fertilizer application to periods of maximum plant uptake. Generally fall and spring applications are recoznrriended, although WSU turf specialists recommend four fertilizer applications per year. • Properly trained persons should apply alI fertilizers. At commercial .and industrial facilities fertilizers should not be applied to grass swales, filter strips, or buffer areas that drain to sensitive water bodies unless approved by the lacal jurisdiction. Integrated Pest Management An Il'M.program might consist ofthe following steps: Step 1: Correctly identify problem pests and understand their life cycle Step 2: Establzsh tolerance thxesholds for pests. Step 3: Monitor to detect and prevent pest problems. Step 9~: Modify the maintenance program to promote healthy plants and discourage pests. Step 5; Use cultural, physical, mechanical, or biological controls first if pests exceed the tolerance thresholds. Step 6: Evaluate and record the e~fecfrveness of the control and` modify maintenance practices to support lawn or landscape recovery and prevent recurrence. For an elaboration of these steps refer to Appendix IV~F. F: :.-}! 2-28 Volume 1V -Source Control BMPs FeF~ruary 2005 BMPs for Description of Pollutant ~ou~•ces: Facilities include roadside catch Main#enance of basins on arterials and within residential areas, conveyance systems, Stormwater detention facilities such as ponds and vaults, oil and water separators, Drainage and biofilters, settling basins, infzltratioz-- systen-zs, and all other types of Treatment stormwater tz•eatznent systems presented in Volume V. Roadside catch Systems basins can remove from 5 to 15 percent of the pollutants present in stormwater. When catch basins are about 60 percent full of sediment, they cease removing sediments. Oil and grease, hydrocarbons, debris, heavy metals, sediments and contaminated water are found in catch basins, oil and water separators, settling basii3s, etc. Pollutant Control Approach: Provide maintenance and cleaning of debris, sediments, and oil from stormwater collection, conveyance, and treatment systems to obtain proper operation. Applicalzle Qperatiotial BMPs: Maintain storznwater treatment facilities according to the O & M procedures presented in Section~4.6 of Volume V in addition to the following BMPs: • Inspect and clean treatment BMPs, conveyance systems, and catch basins as needed, and determine whether improvements in O & M are needed. • Promptly repair any deterioration threatening the structural integrity of the facilities. These include repiaceinent of clean-out gates, catch basin lids, and rock in emergency spillways. • Ensure that storm sewer capacities are not exceeded and that heavy sediment discharges to the sewer system are prevented. • Regularly remove debris and sludge from BMPs used for peals-rate cont~•ol, treatment, etc. and discharge to a sanitary sewer if approved by the sewer authority, or truck to a local or state government approved disposal site. • Clean catch basins when the depth of deposits reaches 60 percent of the sump depth as nrzeasured from the bottom of basin to the invert of the lowest pipe into or out of the basin. However, in no case should there be less than six inches clearance f~rorn the debris surface to the invert of the lowest pipe. Some catch basins (for example, WSDOT Type 1L basins) may have as little as 12 inches sediment storage below the invert. These catch basins will need more frequent inspection and cleaning to prevent scouring. Where these catch basins are part of a storznwater collection azad treatznezit system, the system owner/operator may choose to concentrate maintenance efforts on downstream control devices as part of a systems approach. 2-40 Volume IV -Source Control BMPs February 2005 • Clean woody debris in a catch basin. as frequently as needed to ensure proper operation of the catchbasin. • Post warning sighs; "Dump No Waste -Drains to Ground Water," ccStreaiIlS," "L,aICeS," OI' elnbOSS OIl Or ad~aCeIlt t0 all storlll dI'aIn Inlets " where ~~ractical. • Disposal of sediments and liquids froze. the catch basins must comply with "Recommendations foI•,Managezxlent of Street Wastes" described in Appendix IV-G of this volume. Additional Appticable BMPs: Select additional applicable BMPs fioln this chapter depending on the pollutant sources and activities conducted at the facility. Those BMPs include: • BMPs for Soil Erosion and Sediment Control at Industrial Sites • BMI's for Storage of Liquid, Food Waste, or Dangerous Waste Containers • BMI's for Spills of Oil and Hazardous Substances • BMPs for .illicit Connections to Storm Drains • BMPs for Urban Streets. ,' February 2005 Volume !V -Source Control BMPs 2-49 BMPs for Descriptiozz of Pollutant Sources: Public and conxznercial parking lots Parking and such as retail store, fleet vehicle {including rent-a-car Tats and car Storage o€ dealerships), equiprnent sale and rental parking Tots, and parking Iot Vehicles and driveways, can be sources of toxic lxydracarbons and otlxer organic Equipment compounds, oils and greases, metals, and suspended solids caused by ttee parked vehicles. Pollutant Con#r•ol Approach: If the parking lot is a high-use site as defined below, provide appropriate oil removal equipment for the contaminated stormwater runoff Applicable Olzerational BMPs: • If washing of a parking lot is conducted, discharge the wastewater to a sanitary sewer, if allowed by the local sewer authority, or other approved wastewater treatment system, or collect it for off.-site disposal. • Do not lxose down the area to a storm drain or to a receiving water. -Sweep parking fats, storage areas, and driveways, regularly to collect dirt, waste, and debris. Applicak~le Treatment BMPs: An oil removal system such as an API or CP oil and water separator, catch basin filter, or equivalent BMP, approved by the local jurisdiction, is applicable for parking lots meetizxg the threshold vehicle traffic intensity level of a high-use site. Vehicle High-Use Sites Establishments subject to a vehicle high-use intensity have been determined to be significant sources of oil contamination of startnwater. Examples of potential high use areas include custonxer parkixzg lots at fast food stores, groceay stores, taverns, restaurants, large shopping malls, discount warehouse stores, quick-lobe shops, and banks.' If the PGIS for a high-use site exceeds 5,000 square feet in a threshold discharge area, and oil control BMP from the Oil Control Menu is necessazy. A high-use site at a commercial or industrial establishment lxas one of the fallowing characteristics: (Gaul/Kixzg County, 1994) • Is subject to an expected average daily vehicle traffc {ADT) count equal to or greater than 100 vehicles per 1,000 square feet of gross building area: or • Is subject to storage of a fleet of 25 or more dzesel vehicles that are over IO tons gross weight (trucks, buses, trains, heavy equiprnent, etc.). •~T~ 2-48 Volume !V - Source. Control BMPs ~ February 2005 BMPs for Roofl Description of Pollutant Sources: StoY~nwater runoff fn•om roofs and Building Drains sides of manufacturing and corn~nercial buildings can be sources of at Manufacturing • pollutants caused by leaching of roofung materials, building vents, and and Commercial other air ennission sources. Vapors and entrained liquid and solid Buildings droplets/particles have been identified as potential pollutants in roof/buiIding runoff: Metals, solvents, acidic/alkaline pH, BOD, and organics, a~~e some of the pollutant constituents identified. Pollutant Co~rtrol Approach: Evaluate the potential sources of storznwater pollutants and apply source control BMPs where feasible. Applicable OperationaC Source Control BMPs: • if leaclnates and/or eFnissions from buildings are suspected sources of stornnwater pollutants, then sample and analyze the stormwater drauvng from the building. if a rooflbuilding stonnwater pollutant.source is identified, iznplerrrent appropriate source control measures such as air pollution control equipment, selection of materials, operational changes, material recycle, process changes, etc. February 2008 ~ Volume !V -Source Confrol B1V1Ps 2-59 Attachment "C" Contech 5tormfilter® Maintenance Manual ~T~~r~~T stormFilter Inspection and Maintenance Procedures thi''. ~:rv~'r.y `*r 'rir''i:a,an>.n? 5.s~ Maintenance Guidelines The primary purpose of the Stormwater Management StormFilter` is to filter out and prevent pollutants from entering our waterways. Like any effective filtration system, periodically these pollutants must he removed to restore the StormFilter to its full efficiency and effectiveness. A/laintenance requirements and frequency are dependent on the pollutant load characteristics of each site. Maintenance activities may be required in the event of a chemical spill or due to excessive sediment loading from site erosion or extreme storms. It is a good practice to inspect the system after major storm events. Maintenance PI'OCedUCeS Although there are likely many effective maintenance options, we believe the following procedure is efficient and can be implemented using common equipment and existing maintenance protocols. A two step procedure is recommended as follows: i, Inspection Inspection of the vault interior to determine the need for maintenance. 2. Maintenance Cartridge replacement Sediment removal Inspection and Maintenance Timing At least one scheduled inspection should take place per year with maintenance following as warranted. First, an inspection should be done before the winter season. During the inspection the need fior maintenance should be determined and, if disposal during maintenance will be required, samples of the accumulated sediments and media should be obtained. In addition to these two activities, it is important to check the condition of the StormFilter unit after major storms for potential damage caused by high flows and for high sediment accumulation that may be caused by localized erosion in the drainage area. It may be necessary to adjust the inspection/ maintenance schedule depending on the actual operating conditions encountered by the system. in general, inspection activities can be conducted at any time, and maintenance should occur, if warranted, in late summer to early fail when flows into the system are not likely to be present. Maintenance Frequency The primary factor controlling timing of maintenance of the StormFilter is sediment loading. A properly functioning system will remove solids from water by trapping particulates in the porous structure of the filter media inside the cartridges. The flow through the system wil{ naturally decrease as more and more particulates are trapped. Eventually the flow through the cartridges will be low enough to require replacement. It may be possible to extend the usable span of the cartridges by removing sediment from upstream trapping devices on aroutine as-needed basis in order to prevent material from being re-suspended and discharged to the StormFilter treatment system. Site conditions greatly in#luence maintenance requirements. StormFilter units located in areas with erasion or active construction may need to be inspected and maintained more often than those with fully stabilized surface conditions, The maintenance frequency may be adjusted as additional monitoring information becomes available during the inspection program. Areas that develop known problems should be inspected more frequently than areas that demonstrate no problems, particularly after major storms, tJltimately, inspection and maintenance activities should be scheduled based on the historic records and characteristics of an individual StormFilter system or site. It is recommended that the site owner develop a database to properly manage StormFilter inspection and maintenance programs. Prior to the development of the maintenance database, the following maintenance frequencies should be followed: Inspection One time per year After major storms Maintenance As needed, based on results of inspection (The average maintenance lifecycle is approximately 1-3 years) Per Regulatory requirement In the event of a chemical spill Frequencies should be updated as required. The recommended initial frequency for inspection is one time per year. Storm#ilter units should be inspected after major storms. Second, ii warranted, a maintenance (replacement of the filter cartridges and removal of accumulated sediments) should be performed during periods of dry weather. Sediment removal and cartridge replacement on an as needed basis is recommended unless site conditions warrant. Once an understanding of site characteristics has been established, maintenance may not be needed for one to three years, but inspection is warranted and recommended annually.. Inspecfiior~ Procedures The primary goal of an inspection is to assess the condition of the cartridges relative to the level of visual sediment loading as it relates to decreased treatment capacity. It may be desirable to conduct this inspection during a storm to observe the relative flow through the filter cartridges. ff the submerged cartridges are severely plugged, then typically large amounts of sediments wilt he present and very little flow will be discharged from the drainage pipes. If this is the case, then maintenance is warranted and the cartridges need to be repfaced, Warning: In the case of a spill, the worker should abort inspection activities until the proper guidance is obtained. Notify the local hazard control agency and CONTECkt Stormwater Solutions immediately. To conduct an inspection: Irnporta:nt:. Inspection should'be performed`by a,pe!•son who is familiar with the operation and configuration of the StormFilterTreatment unit. 1. If applicable, set up safety equipment to protect and notify surrounding vehicle and pedestrian traffic. 2. Visually inspect the external condition of the unit and take notes concerning defects/problems. 5. Be sure to record the level of sediment build-up on the floor of the vault; in the forebay, and on top of the cartridges. If flow is occurring, note the flow of water per drainage pipe. Record all observations. Digital pictures are valuable for historical documentation. 6. Close and fasten the access portals. 7, Remove safety equipment. $. If appropriate, make notes about the Iota! drainage area relative to ongoing construction, erasion problems, or high loading of other materials to the system. 9. biscuss conditions that suggest maintenance and make decision as to weather or not maintenance is needed. Maintenance Decision Tree The need for maintenance is typically based on results of the inspection. The following Maintenance Decision Tree should be used as a general guide. (Other {actors, such as Regulatory Requirements, may need to be considered) a. If >4" of accumulated sediment, maintenance is required. 2. Sediment loading an top of the cartridge. a. If > 1/4" of accumulation, maintenance is required. 3. Submerged cartridges. a. If >4" of static water in the cartridge bay for more that 24 hours after end of rain event, maintenance is required. 4. Plugged media. a. If pore space between-media granules is absent, maintenance is required. 5. Bypass condition, a. If inspection is conducted during an average rain fall event and StormFilter remains in bypass condition (water over the internal outlet baffle wall or submerged cartridges), maintenance is required. 6. Hazardous material release. a. If hazardous material release (automotive fluids or other) is reported, maintenance is required. 7. Pronounced scum line. a. If pronounced scum line (say ~ 1/4" thick) is present above top cap, maintenance is required. 8. Calendar I_ifecycle. a. If system has not heen maintained for 3 years maintenance is required. 1. Sediment loading on the vault floor. 3. Open the access portals to the vault and allow the system vent. 4. Without entering the vault, visually inspect the inside of the unit, and note accumulations of liquids and solids. Assumptions • No rainfall for 24 hours or more • No upstream detention (at least not draining into StormFilter) • Structure is online • Outlet pipe is clear of obstruction • Construction bypass is plugged Mainfienance Depending on the configuration of the particular system, maintenance personnel will be required to enter the vault to perform the maintenance. Important: If vault entry is required, OSHA rules for confined space entry must be followed. Filter cartridge replacement should occur during dry weather. It may be necessary to plug the filter inlet pipe if base flows is :occurring. Replacement cartridges can be delivered to the site or customers facility, Information concerning how to obtain the replacement cartridges is available from CONTECH Stormwater Solutions. Warning: In the case of a spill, the maintenance personnel should abort maintenance activities until the proper guidance is obtained. Notify the local hazard control agency and CONTECH Stormwater Solutions immediately. To conduct cartridge replacement and sediment removal maintenance: 1. If applicable, set up safety equipment to protect maintenance personnel and pedestrians from site hazards. 2. Visually inspect the external condition of the unit and take notes concerning defects/problems. 3. Open the doors (access portals} to the vault and allow the system to vent. 4. Without entering the vault, give the inside of the unit, including components, a general condition inspection. 5. Make notes about the external and internal condition of the vault. Give particular attention to recording the level of sediment build-up on the floor of the vault, in the forebay, , and on top of the internal components. 6. Using appropriate equipment offload the replacement cartridges (up to 150 lbs. each) and set aside, 7. Remove used cartridges from the vault using one of the following `methods Method 1: A. This activity will require that maintenance personnel enter the vault to remove the cartridges from the under drain manifold and place them under the vault opening for lifting (removal}, unscrew (counterclockwise rotations) each filter cartridge from the underdrain connector. Roll the loose cartridge, on edge, to a convenient spot beneath the vault access. Using appropriate hoisting equipment, attach a cable from the boom, crane, or tripod to the loose cartridge. Contact CONTECH Stormwater Solutions for suggested attachment devices. B. Remove the used cartridges (up to 250 fbs, each} from the vault. Important: Care must be used to avoid damaging the cartridges during removal and installation. The cost of repairing components damaged during maintenance will be the responsibility of the owner unless CONTECH Stormwater Solutions performs the maintenance activities and damage is not related to discharges to the system, C. Set the used cartridge aside or load onto the hauling truck. d. Continue steps a through c until all cartridges have been removed. Method 2: A. Enter the vault using appropriate confined space protocols. B. Unscrew the cartridge cap. C. Remove the cartridge hood screws (3) hood and float. D. At location under Structure access, tip the cartridge on its side. lirrp,or#ant: Note that cartridges containing leaf media (CSF.) do not require unscrewing from their connectors. Take care not to damage the manifold connectors. This connector should remain installed in the manifold and could be capped during. the maintenance activity to prevent sediments from entering the underdrain manifold. Importar~#: Note that cartridges containing media other than the Icaf media require unscrewing from their threaded connectors. Take care not to damage the manifold connectors. This connector should remain installed in the manifold and capped if necessary. D. Empty the cartridge onto the vault floor. Reassemble the empty cartridge. E. Set the empty, used cartridge aside or load onto the hauling truck, 8. Remove accumulated sediment from the floor of the vault and from the forebay,-This can most effectively be accomplished by use of a vacuum truck. 9. Once the sediments are removed, assess the condition of the vault and the condition of the connectors. The connectors are short sections of 2-inch schedu#e A0 PVC, or threaded schedule 80 PVC that should protrude about 1 "above the floor of the vault. Sightly wash down the vault interior. a. !f desired, apply a light tooting of FDA approved silicon tube to the outside of the exposed portion of the connectors. This ensures a watertight connection between the cartridge and the drainage pipe, b. Replace any damaged connectors. i 0. Using the vacuum truck boom, crane, or tripod, lower and install the new cartridges. Once again, take care not to damage connections. 1 1, Close and fasten the door. 1 Z. Remove safety equipment. i 3. Finally, dispose of the accumulated materials in accordance with applicable regulations. Make arrangements to return the used empty cartridges to CONTFCII Stormwater Solutions. E Continue steps a through e until a!1 cartridges have been removed. Related Maintenance Activities Performed on an as-needed basis StormFilter units are often just one of many structures in amore comprehensive stormwater drainage and treatment system. In order for maintenance of the StormFilter to be successful, it is imperative that all other components be properly maintained The maintenance/repair of upstream facilities should be carried out prior to StormFilter maintenance activities. In addition to considering upstream facilities, it is also important to correct any problems identified in the drainage area. Drainage area concerns may include: erosion problems, heavy oil loading, and discharges of inappropriate materials. L~jv PAPER iED Material Disposal The accumulated sediment found in stormwater treatment and conveyance systems must be handled and disposed of in accordance with regulatory protocols. It is possible for sediments to contain measurable concentrations of heavy metals and organic chemicals (such as pesticides and petroleum products}. Areas with the greatest potential for high pollutant loading include industrial areas and heavily traveled roads. Sediments and water must be disposed of in accordance with all applicable waste disposal regulations. When scheduling maintenance, consideration must be made for the disposal of solid and liquid wastes. This typically requires coordination with a local landfill for solid waste disposal. For liquid waste disposal a number of options are available including a municipal vacuum truck decant facility, focal waste water treatment plant or on-site treatment and discharge. , ~~ 800.925,5210 contechstorrr~water.com Support Drawings and specifications are available at contechstorrr7wa#er.com. • Site-specific design support is available from our engineers. ©2007 CQNTECH stormwater Solutions CONTECH Construction Products inc. provides site solutions for the civil engineering industry. CONTECH's portfolio includes bridges, drainage, sanitary sewer, stormwater and earth stabilization products. For in#ormation on other CONTECH division o#ferings, visit contech-cpi.com or call $00,338.1 1 22 Nothing in this catalog should be construed as an expressed warranty or an implied warranty of merchantability or fitness for any particular purpose. See the CQNTECH standard quotation or acknowledgement for applicable warranties and other terms and conditions of sale. i ~- • '•~r Date: Personnel: Location: System Size: System Type: Vault ^ Cast-In-Place ^ Linear Catch Basin ^ Manhole ^ Other [_] Date: I Sediment Thickness in 1=orebay: € Sediment Depth on Vault Floor: Structural Damage: Estimated Flow from Drainage Pipes (if available): Cartridges Submerged: Yes ^ No ^ Depth of Standing Water: StormFilter Maintenance Activities {check off if done and give description) ^ Trash and Debris Removal: ^ Minor Structural Repairs: ^ Drainage Area Report Excessive Oil Loading: Yes ^ No ^ Source: Sediment Accumulation on Pavement: Yes ^ No ^ Source: Erosion of Landscaped Areas: Yes ^ No ^ Source: Items Needing Further Work: ~ _.. ............. Owners should contact the local public works department and inquire about how the department disposes of their street waste residuals. Other Comments: Review the condition reports from the previous inspection visits_ • ~~ Date: Personnel: Location: System Size: System Type: Vault ^ Cast-In-Place ^ List Safety Procedures and Equipment Used: System Observations Months in Service: Oil in Forebay: Yes Sediment Depth in Forebay: Sediment Depth on Vault Floor. Structural Damage: Drainage Area Report Excessive Oil Loading: Yes ^ Sediment Accumulation.onPavement: Yes [] Erosion of Landscaped Areas: Yes ^ No ^ Source: No ^ Source: No ^ Source: Stormf=i(ter Cartridge Replacement Maintenance Activities Remove Trash and Debris: Yes ^ No ^ Details: Replace Cartridges: Yes ^ No ^ Details; Sediment Removed: Yes [~ No ^ Details: Quantity of Sediment Removed (estimate?): Minor Structural Repairs: Yes ^ No ^ Details: Residuals (debris, sediment) Disposal Methods: No ^ Linear Catch Basin ^ Manhole ^ Qther ^ Notes: ~~-` ~ N r~ STORMVl1AT~R --.~„~ SOLUTIONS,~~ 4pera~ion and Maintenance CatchBas~n StormFilterTM Important: These guidelines should be used as a parf of your site stormwater plan. Overview The CatchBasin StormFilterT"" (CBSF} consists of amulti-chamber steel, concrete, or plastic catch basin unit that can contain up to four StormFifter cartridges. The steel CBSF is offered both as a standard and as a deep unit. The CBSF is installed flush with the finished grade and is applicable for both constrained lot and retrofit applications. It can also be fitted with an inlet pipe for roof leaders or similar applications. The CBSF unit treats peak water quality design flows up to 0.~3 cfs, coupled with an internal weir overflow capacity of 1.0 cfs for the standard unit, and ~ .8 cfs for the deep steel -and concrete units. Plastic units have an internal weir overflow capacity of 0.5 cfs. Design Operation The CBSF is installed as the primary receiver of runoff, similar to a standard, grated catch basin. The steel and concrete CBSF units have an H-20 rated, traffic- bearing lid that allows the filter to be installed in parking lots, and for all practical purposes, takes up no land area. Plas#ic units .can be used in landscaped areas and for other non-traffic-bearing applications. The CBSF consists of a sumped inlet chamber and a cartridge chamber(s). Runoff enters the sumped inlet chamber either by sheet flow from a paved surface or from an inlet pipe discharging directly to the unit vault. The inlet chamber is equipped with an internal baffle, which traps debris and floating oil and grease, and an overflow weir. While in the inlet chamber, heavier solids are allowed to settle into the deep sump, while lighter solids and soluble pollutants are directed under the baffle and into the cartridge chamber through a port between the baffle and the overflow weir. Once in the car#ridge chamber, polluted water ponds and percolates horizontally through the media in the filter cartridges. Treated water collects in the cartridge's center tube from where it is directed by an under-drain manifold to the outlet pipe on the downstream side of the overflow weir and discharged. When flows into the CBSF exceed the water quality design value, excess water spills over the overflow weir, bypassing the cartridge bay, and discharges to the outlet pipe. Applications The CBSF is particularly useful where small flows are being treated or far sites that are flat and have little available hydraulic head #o spare. The unit is ideal for applications in which standard catch basins are to be used. Both water quality and catchment issues can be resolved with the use of the CBSF. Retro-Fit The retrofit market has many possible applications for the CBSF. The CBSF can be installed by replacing an existing catch basin withou# having to "chase the grade," thus reducing the high cost of re- piping the storm system. 02006 CONTECF~ Starmwater 5olufions Toll-free: 800.548.4667 1 of 3 contechsiormwatsr.carra CatchBasin StarmFilter Operation and Maintenance Guidelines Maintenance Guidelines Maintenance procedures for typical catch basins can be applied to the CatchBasin StormF'ilter (CBSF). The filter cartridges contained in the CBSF are easily removed and replaced during maintenance activities according to the following guidelines, 1. Establish a safe working area as per typical catch basin service activity. 2. Remove steel grate and diamond plate cover (weight. 100 lbs. each}. 3. Turn cartridge(s) counter-clockwise to disconnect from pipe manifold. 4. Remove 4" center cap from cartridge and replace with lifting cap. 5. Remove cartridges} from catch basin by hand ar with vactor truck boom. 6. Remove accumulated sediment via vactor truck (min. clearance 13" x 24"). 7. Remove accumulated sediment from cartridge bay. (min. clearance 9.25" x 11") 8. Rinse interior of both bays and vactor remaining water and sediment. Media may be removed from the filter cartridges using the vactor truck before the cartridges are removed from the catch basin structure. Empty cartridges can be easily removed from the catch basin structure by hand. Empty cartridges should be reassembled and returned to CONTECH Stormwater Solutions, as appropriate. Materials required include a lifting cap, vactor truck, and fresh filter cartridges. Contact CONTECH Stormwater Solutions for specifications and availability of the lifting cap. The vactor truck must be equipped with a hose capable of reaching areas of restricted clearance. The owner may refresh spent cartridges. Refreshed cartridges are also available from CONTl;CF1 Stormwater Solutions on an exchange basis. Contact the main#enance department of CONTECH Stormwater Solutions at {503) 240-3393 for more information. Main#enance is estimated at 26 minutes of site time. For units with more than one cartridge, add approximately 5 minutes for each additional cartridge. Add travel time as required. 9. Install fresh cartridge(s) threading clockwise to pipe manifold. 10. Replace cover and grate. 11. Return original cartridges to CONTECH S#ormwater Solutions for cleaning and media disposal. 0200& CONTECH Stormwater Solutions loll-tree: 800.548.4667 2 of 3 confechstormwafer.com Catch Basin StormFiiter Operation and tvlaintenance Guidelines Mosquito Abatement In certain areas of the United States, mosquito abatement is desirable to reduce the incidence of vectors. In BMPs with standing water, which could provide mosqui#o breeding habitat, certain abatement measures can be taken. 1. Periodic observation of the standing water to defermine if the facility is harboring mosquito larvae. 2. Regular catch basin maintenance 3. Use of larvicides containing Bacillus fhuringiensis israelensis (BTi). BTI is a bacterium toxic to mosquito and black fly larvae. in some cases, the presence of petroleum hydrocarbons may interrupt the mosquito growth cycle. Using Larvicides in the CafchBasin SformFilfer Larvicides should be used according to manufacturer's recommendations. Two widely available products are Mosquito Dunks and Summit B.t.i. Briquets. For more information, visit http:llwww.summitchemical.comlmos_ctrlld efault.htm. The larvicide must be in contact with the permanent pool. The larvicide should also be fastened to the CatchBasin StormFilter by string or wire to prevent displacement by high flows. A magnet can be used with a steel catch E~asin. For more information on mosquito abatement in stormwater BMPs, refer to the following: httpalwww.ucmrp.ucdavis.edulpublicationsl managingmosquitoesstormwater8125. pdf ©2006kCONTECH Stormwater Solutions Toil tree: 800~.548.4667~ °..,~,._..,._.,...F, n,~,,..<.~ N.,_..,.,.~„~,,,.~r..,.«,.~v-~~°~3mof 3 coniechsl:ormwa#eccom Ca#chBasin stormFilter Operation and Maintenance Guidelines Attachment "D" Stormtech® Maintenance Manual ~® lJelerrlion • Aeterttror~ • Recharge Subsurfiace Stormwater ManagementSU IsolatorT"~ Rouu Ol*M Manual StormTec~i`J~ Ct~am~er System for Stormwater Management w TTf Nl~ l.t INTRODUCTION An important component of any Stormwater Pollutipn Prevention Plan is inspection and maintenance. The StormTech isolator Row is a patent pending technique to inexpensively enhance Total Suspended Solids (TSS) removal and provide easy access for inspection and maintenance. ].2 THE ISOLATOR'" ROW The Isolator Row is a row of StormTech chambers, either SC-740 or SG310 models, that is surrounded with filter fabric and connected to a closely located manhole for easy access. The fabric-wrapped chambers provide for settling and filtration of sediment as storrra water rises in the Isolator Row and ul€imately passes through the filter fabric. The open bottom chambers and perforated side- walk allow storm water to flow both vertically and horizon- tally out of the chambers. Sediments are captured in the Isolator Row protecting the storage areas of the adja- cent stone and chambers from sediment accumulation. Two dif€erent fabrics are used for the Isolator Row. A woven geotextile fabric is placed between the stone and the Isolator Row chambers. The tough geotextile provides a media for storm water filtration and provides a durable surface for maintenance operations. It is also designed to prevent scour of the underlying stone and remain intact during high pressure jetting. Anon-woven fabric is placed over the chambers to provide a filter media for flows passing through the perforations in the sidewall of the chamber. The Isolator Row is typically designed to capture the "first flush" and offers the versatility to be sized on a vol- ume basis or flow rate basis, An upstream manhole not only provides access to the isolator Row but typically includes a high flow weir such that storm water flowrates or volumes that exceed the capacity of the Isoiator Row overtop the over flow weir and discharge through a manifold to the p#her chambers. The Isolator Raw may also be part of a treatment train. By treating storm water prior to entry into the chamber system, the service fife can be extended and pollutants such as hydrocarbons can be captured. Pre-treatment best management practices can be as simple as deep sump catch basins, oil-wa#er separators or can be inno- vative storm water treatment devices. The design of the treatment train and selection of pretreatment devices by the design engineer is often driven by regulatory requirements. Whether pretreatment is used or not,- the Isoiator Row is recommended by StormTech as an effective means to miriimize maintenance requirements and maintenance costs. Note: See the StormTech Design Mantra! for detailed information on designing inlets for a StormTech system, including the lsolator,4ow. StormTech Isolator Row with Overflow Spillway (not to scale) MANHOLE wires ovER~LOw WEIR ECCENTRIC HEADER OPTIONAL ACCESS 2 Call StormTech at 888.882.2694 or visit our wet~site at wwwstormtech.com for iechr~icat and product information. Looking down the Isolator Row from fhe manhole opening, woven geotextile is shown between the chamber and stone base. ~~ ~ ~1 ~~~ StormTech° 2.i (~JSPECr[ON The frequency of lnspectiori and Maintenance varies by location. A routine inspection schedule needs to be established #or each individual location based upon site specific variables. The type of land use (i.e. industrial, commercial residential), anticipated pollutant toad, per- cent imperviousness, climate, etc. all play a critical role in determining the actual frequency of inspection and maintenance practices. At a minimum, StormTech recommt/nds annual inspec- tions. Initially, the Isolator Row should be inspected every 6 months for the first year of operation. For subsequent years, the inspection should be adjusted based upon previous observation of sediment deposition. The isolator Row incorporates a combination of standard manhole(s) and strategically located inspection ports (as needed). The inspection ports allow for easy access to the system from the surface, eliminating the need to per#orm a confined space entry for inspection purposes. If upon visual inspection it is found that sediment has accumulated, a stadia rod should be inserted to deter- mine the depth o€ sediment. When the average depth of sediment exceeds 3 inches throughout the length of the Isolator Row, clean-out should be performed. ~.2 MA~rrr~~rAacE The Isolator Row was designed to reduce the cost of periodic maintenance. 8y "isolating" sediments to just one row, costs are dramatically reduced by eliminating the need to clean out each raw of the entire storage bed. if inspection indicates the potential need for main- tenance, access is provided via a manhole(s) located on the ends} of the row for cleanout. If entry into the manhole is required, please follow local and OSHA rules for a confined space entries. StormTech Isolator Row (not to scale) Examples of culvert cleaning nozzles appropriate for Isolator Row maintenance. {These are not StormTech products.) Maintenance is accomplished with the JetVac process. The JetVac process utilizes a high pressure water noz- zle to propel itself down the Isolator Row while scouring and suspending sediments, As the nozzle is retrieved, the captured pollutants are flushed back into the man- hole for vacuuming. Most sewer and pipe maintenance companies have vacuumlJetVac combination vehicles. Selection of an appropriate .JetVac nozzle will improve maintenance efficiency. Fixed nozzles designed for cul- verts or large diameter pipe cleaning are preferable. Bear facing jets with an effective spread of at least 45" are best. Most JetVac reels have 400 feet of hose allow- ing maintenance of an Isolator Row up to 50 chambers long. The JetVac process shall only be performer! on StormTech Isolator Rows that have AASHTO class ~ woven geotextile {as specified by StormTech) aver their angular base stone. covER ENTIRE Row wlrtt AASHro Mzas i2" MIN i6 25° MAX OD PIPE INSPECTION PORT CLASS 2 NON-WOVEN GEOTEXTlLE SET i.5" FROM BDTTONt LOCATfON PER SC-740 - 8' WIDE STRIP STORMTECH OF CHAMBER ENGINEER'S DRAWING SC-3t0-5'WIDESTRIP ENDCAP CA BA O AN '2FT SU ~T~„ ~r CH -- SIN R . _ ...__._ Ot~ S /fl I~ Y~' I\ yJ a~~~ J~IIy 1 ~ ~ .._ I\ Y/~V.1 i L ~~ll v},$~ylr;uz ~~ ~~~~11~ ~~ ~~x ~~ ~~ y'r~ '~ . ~ Kr MIN. P ~ t - ,- ~~ -~tl ~1i ~ T H -WOVEN GEOTEXTILE THAT MEETS AASHTO M288 CLASS 1 ~~~ hiti,2l11HtMkNI S, Brl WLtN STONE BASE ANf? CHAMBERS SC-740 ---- 5'-5' wiDE STRIP SC-310 ---- 4' WIDE STRIP .t r ~~ Call StormTech at 888.892.2694 or visit our website at www.stormtecf~.corn for technical and product information. 3 Step t) Inspect fsatator Row for sediment StormTech tsotator Row (not to scale) A) Inspection ports•(if present) i) -- i. Remove lid from floor box frame ii. Remove cap from inspection riser iii. Using a flashlight and stadia rod, measure depth of sediment and record results on maintenance log. iv. If sediment is at, or above, 3 inch depth proceed to Step 2. If not a proceed to step 3. S} A11 Isolator Rows i. Remove cover from manhole at upstream end of Isolator Row ii, Using a flashlight, inspect down Isolator Row through outlet pipe 1. Mirrors on poles or cameras may be used to avoid a confined space entry 2. Follow QSHA regulations for confined space entry if entering manhole iii. If sediment is at or above the lower row of sidewatl holes (approximately 3 inches) proceed to Step 2. If not proceed to Step 3. Step 2) Clean out Isolator Row using the JetVac process A) A fixed culvert cleaning nozzle with rear facing nozzle spread of 45 inches or more is preferable B) Apply multiple passes of JetVac until backflush water is clean C) Vacuum manhole sump as required Step 3J Replace all caps, lids and covers, record observations and actions Step 4} lnspect & clean catch basins and manholes upstream of the StormTech system Sample Maintenance E_og StormTech® Detentian • Retention • Recharge Stabstarface Stormwater Management" 20 Beaver Roatl, Suite 104 ~ Wethersfield f Connecticut ~ 08109 860.529.8188 ~ 888.892.2694 ~ fax 866.328.8401 ~ wwwstormtech.com S1armTech pratlucts are covered by one Dr more of the following patents: U.S. Patents: 5,401,459; 5,511,903; 5,716,1fi3; 5,588,778; 5,839,844; Canadian Patents: 2,158,418 Other U.S. and Foreign Patents Pending Printed in U.S.A. O Copyright. All rights reserved. StormTech ILC, 2004 ! 5090104-t I,7 ~~~.'„~~ 13.1 TREATMENT TRAIN INSPECTION AND MAINTENANCE The StormTeoh recommended treatment train inlet system has three tiers of treatrrient upstream of the StormTech chambers. It is recommended that inspection and main- tenance (I&M} be initiated at the furthest upstream treat- ment tier and continue downstream as necessary. The #ollowing I&M procedures follow this approach providing t&M information in the following order: Tier i -- Pretreatment (BMF'); Tier 2 -StormTech Isolator Row, and ;Tier 3 - Eccentric Pipe Header System. 13.2 CATCHBASIN/MANHOLE I&M Typically a stormwater system will have catchbasins and manholes upstream of the detentionlretention sys- tem. In some cases thew may be the only pre-treatment devices. Regular I&M of catchbasins and manholes should be scheduled and performed as part of a site's routine maintenance plan. CatchbasinlManhole -- Step-i7y-Step Maintenance Procedures 1) 9nspect catch basins and manholes upstream of StormTech chambers for sediment 2) Remove grate or cover 3) Skim off oils and floatables 4) Using a stadia rod, measure the depth of sediment 5) tf sediment is at a depth greater than 6" proceed to step E. If not proceed to step 7. 6} Vacuum or manually remove sediment 7) Replaoe grate 8) Record depth & date and schedule next inspection Figure 18 -- t:atchUasinlManhole 1&M Steps A, 5, 6 13.3 PRE-TREATMENT DEVICE I&M Manufacturer's I&M procedures should be followed for proprietary pretreatment devices such as baifie boxes, swirl concentrators, oil-water separators, and #ittration units. Tahle t0 provides some general guidelines but is not a substitute for a manufacturer's specific instructions. TABlE 1©-Pretreatment Inspection at~d Maintenance Guidelines r ~ ~ i _ _ StormTech fsolator7'" Aow __ W Y ~ Bi-Annually _ ~~ ~, ~i Je1Vac - Culverf Cleaning Nozzle t'reterred Sediment Basin .~..__.__. ____-- _ _ Catch Sasin Sustp Quarterly or after large storm event -_-__W_._.__- W.~____,_.._....-----.___..__ _.__ Quarterly Excavate sediment __.______.__----__.___....-- -.- Excavate, pump, or vacuut~ Sedimentation Structure _ __ ___ _ Quarterly _.__ - _ -._. ~ _ Excavate, pump, or vacuum ~~ Catch Basin Filter Bags After all storm events Glean and/or replace tiller bags Porous Pavement Quarterly Sweep Pavement Pipe Header Design Quarterly Excavate, pump, or vacuum Water fluality Inlet __~.._.._.._~_. ~__m_ ._.~._.._.-.- Quarterly : ~ Excavate, pump or vacuum . _ . ~ ~ Sand Filters ~~ - - .___ ..__ Quarterly or alter dorm evens _ _ . _ ~ Remove & replace sand Pilfer _ ~ This schedule does not accourrf for regional or site variables, local municipal guidelines should be followed for inspection when available. x The methods stated are minimum guidelines for removal and cleaning of system. Other methods may apply. Call StormTecf~ at 8fi0.529.8i88 or 888.892.2694 or visit our website ai wwwstormtech.com for tecf~nicaf and product information. 27 13.4 ISOLATORT[" ROW lNSPfCTION Regular inspection and maintenance are essential to assure a properly functioning stormwater system. Inspection is easily accomplished through the manhole or optional inspection parts of an Isolator Row. Please follow local and OSHA rules for a confined space entry. Inspection ports can allow inspection to be accomplished completely from the surface without the need fora con- fined space entry. Inspection ports provide visual access to the system with the use of a flashlight. A stadia rod may be inserted to determine the depth of sediment. If upon visual inspection it is found that sediment has accumulated to an average depth exceeding 3" (76 mm), cleanout is required. A StormTech Isolator Row shou4d initially be inspected immediately after completion of the site's construction. While every effort should be made to prevent sediment from entering the system during construction, it is during thfs time that excess amounts of sediments are most likely to enter any stormwater system. Inspection and maintenance, if necessary, should be performed prior to passing responsibility over to the site's owner. Once in normal service, a StormTech Isniator Raw should he inspected bi-annually until an understanding of the sites characteristics is developed. The site's maintenance manager can then revise the inspection schedule based on experience or local requirements. 13.5 #S~LATOR RQW MAIHTIwNANCf Je#Vac maintenance is required if sediment has been col- lected to an average depth of 3' (76 mm) or more inside the Isolator Row. The JetVac process utilizes a high pressure water nozzle to propel itself down the Isolator Row while scouring and suspending sediments. As the nozzle is retrieved, a wave of suspended sediments is flushed back into the manhole for vacuuming. Most sewer and pipe maintenance companies have vacuum/ JetVac combination vehicles. Fixed nozzles designed for culverts or large diameter pipe cleaning are preferable. Rear facing jets with an effective spread of at least 45" (1140 mm) are best. Most JetVac reels have a mini- mum of 400 feet (122 m) of hose allowing maintenance of an Isolator Row up to 50 chambers long. The JetVac process sha11 only be performed on StormTech Rows that have AASHTO class 1 woven geotextile over their angular base stone. Examples of culvert clearriag nozzles appropriate for Isalafar Ro[:~ maintenance. (These are not StormTecll t~rndUCts. } _.......... 22 Cail StormTech at 860.529.8788 or 888.892.2694 or visit our websito at www.stormtech.corn for ?e:chnrca~ 7r~tl produce 3r,farrrraEfor~ Looking down the Isolator Ro~v. A ryprca! Jeti/ac truck. (This is not a StorrrfTech product,) ~~n~ ;n S~e~rmTe~ch® S'L4RMTECH ISOLATOR`" ROW -STEP-BY S~I:P 1MQINT~NANCE PRO{CI7~lRCS Step t) Inspect Isolator Row for sediment A) Inspection ports (if present) i. Remove lid from floor box frame ii. Remove cap from inspection riser iii. Using a flashlight and stadia rod, measure depth of sediment iv. If sediment is at, or above, 3" (76 mm) depth proceed to Step 2. If not proceed to step 3. B) All Isolator Rows i. Remove cover from manhole at upstream end of Isolator Row ii. Using a flashlight, inspect down Isolator Row through outlet pipe 1. Mirrors on poles or cameras may be used to avoid a con#ined space entry 2. Follow OSHA regulations for confined space entry if entering manhole iii. If sediment is at or above the lower row of sidewall holes [approxirrtately 3" (76 mm)) proceed to Step 2. If not proceed to Step 3. Step 2) Clean out isolator Row using the JetVac process A) A fixed culvert cleaning nozzle with rear facing nozzle spread of 45" (1140 mm) or more is preferable B) Apply multipEe passes of JetVac until backflush water is clean C) Vacuum manhole sump as required Step 3} Replace all caps, lids and covers Step 4) Inspect and clean catch basins and manholes upstream of the StarmTech system following the procedures for Classic Manifold inlet System 4 Gall Storm7ech at 86D.529.8188 or 888.892.2694 or visit our website at wwwstormtech.com for technical and product information, 23 IFigure 19 StormTech Isolator Row (not to scale) 13.6 ECCENTRIC PIPE HEADER INSPECTION Theses guidelines do not supercede a pipe manufac- turer's recommended t&M procedures. Consult with the manufacturer of the pipe header system for specific !&M procedures. Inspection of the header system should be carried out quarterly. On sites which generate higher levels of sediment more frequent inspections may be necessary. Headers may be accessed through risers, access por#s or manholes. Measuremont of sediment may be taken with a stadia rad or similar device. C1ean- out of sediment should occur when the sediment volume has reduced the storage area by 25% or the depth of sediment has reached approximately 25% of the diameter of the structure. ]3.7 ECCENTRIC PIPE HEADER MAINTENANCE Cleanout of accumulated material should be accom- plished by vacuum pumping the material from the head- er, Gleanout should be accomplished during dry weath- er. Care should be taken to avoid flushing sediments out through the outlet pipes and into the chamber rows. Eccentric Header Step-by-Step Maintenance Procedures 1. Locate manholes, access ports or risers connected to the header system 2. Remove grates or covers 3. Using a stadia rod, measure the depth of sediment 4. If sediment is at a depth of about 25% pipe volurrte or 25% pipe diameter proceed to step 5. If not proceed to step 6. 5. Vacuum pump the sediment. Do not flush sediment out inlet pipes. 6. Replace grates and covers 7. Record depth and date and schedule next inspection Figure 2tl ~ Ecceutric Mauif©Ed Maintenance 3, 4, 5 24 Gall StormTech at 860.529.8188 or 888.892.2594 or visit our wet3site at wwwstormtech.com for tecl~i~ical and product information.