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Yelm Plaza Storm Drainage Report No 1 (2)Yelm Plaza SIN INANE ~° ~l ~'lza ~~l a hi~z~t~rz Eel}r~aary 2007 rojet Ifo .anon. Project; I'rearecl fcar: C%~antact: ~ie~vin Ag~nc~ e~Llr3. sCllCtlf?n: PrCFjeCt Li3TI{Jer: r(2Jeet L1T1taCt ~"oJ~C~ Iisllif'~r ~1 laze F'c~~Brest Partners, LI. e el~.inc~ra Sr. 360-352-200 It ~~el ~It11 11DSt}n Pr°eare by. fly is Engineering 300 I}escl~tes t~a~ , Ste, X15 ~'nxnater, A S50I (360) 705-247 l~ A~ ~360~ 705-243 intact: Chris 1VI_ erritt, P.E. Pr~jecte 05026 File dumber: 05026 r.oc ~`~ ~~ `~' P~tt~JEC'.'r E~l~INI'El3' CE~#TIEICATION: I hereby certify that tlxis final ~z°ainage Report for YeF.nz. Plaza in helm, YtFashington has been prepared by zne ar under my supervision and meets the zntent. of ttae t~rSDflE Stormwater Management Manual fc:r ~r4resterr~ ~iFashington, 1~1?2 ed., and the ~'hurston Counter L,rainage l3esigrs ancfl Erasion Control Manual (DI?EGM}; 199 ed., unless noted ot,hcrwise, acid zaarmal standards of engineering practice. I understand that the ,jurisdiction does not and will not assname liability far the sufficiency, suitability, ar performance of ~arn~~~ t` o~2itn~a elesi~i~e,~ £rFr t~ia ctevelapancut. 1. ~~ !i f' .;.._..~,..~.. L ~ ~~ 4'7!6 ~ f le tent ~~~T rar ra~cE~Ar~c ~z~~a~v ................................................a..,,,,..,...,.. ~ S~~`~~CkN 1. - REQUI~I~ ~TTi~T~NC'E..........._ ................a.................7 S~~TIQ2~F `~ - ~tESE'O~3SI~~ E ~I~~xANII4'I'It~}N ...................................... ] 7 ~~C',T~4I~T 3 - VEGETA'I°I(}N I47~NA~x~MN~' ~Z,~~I~T .............................. 17 S~C~'ION ~4 - ~C}€i~.C'~ C4N°3'~t~L......._ ................._..,,.................._........ 27 ~~ 1 T T1 1 - J~ ~ ~ ~'~ prepared for: ontact~ rj~~t ve ie ~'ourbest partners, I13~C ike cliinnon fir. 360-32-.2(104 22730130:900 X3.23 Acres -]_ lO Plaza I9r I~,TE ~elnz, A 5J7 grading, IJtili.ty, Building, etc. ~Sectian 24 ~`ownship 37 I~lorth Stange 3 Bast, ~.1V3. 'I?he project site is Iocated adjacent to elnz Avenue (~. X07) in helm, Washington. 'The applicant proposes to construct a cozaamercial building and site improvements for the use of servicing autoanobiles. The development will be constructed. in ox~e phase. Construction will include clearing and grading of the site, stozm drainage improvements, underground utilities, parking lot construction. and paving, frontage improvements, and extension of water and sewer to the building. tor~rawater facilities will consist of catch basins with associated piping, a ~orteclzs vault for stor .water treatment, and underground torrpech chambers for storznwater storage and infaltration back to grauizdwater. tc~r ater Treat en: All on-site stornzwater runoff will sheet flow to catch basins azzd piped to a ~fortecs treatment vault. `S'he proposed ~%orteclzs unit meets the minimum tre~.tinent requirements per the t~~. See the aptaencl~~ ft~r st.ur~tt~r facility sizing calculations. 3 Stor a~v~er ~ts~ra oof ono I~.oof downspouts shall e taght lined to the unergrorind storage chambers with 6"-~" diameter I'~C pipe. SECTIt~N 2 -EXiSTih1~ ~®ItiIDITI~IVS There appears to e no lzastory of flooding or other drainage related pxolerzzs on the existing site or tributary to the existing site. I 3 -I FILT I S 6 IL. E The foal Conservation service { ;C) soil sua°vey of Thurston County classifies the o-site sails as panaway gravelly dandy l~oarn {~Iydrol.ogac group ~). foil testing confirmed the parzaway series classification. ~ design infiltration rate of 'Q inches per hour lzas beers arsed :in azzfiltration facility design. fee appendix far soils report. TI 4 - !.!. E TIC TE l'~o on-sate wells were found during our site investigationz of this proposed development. Water arzd sanitary sewer servaces for the proposed project wall be provided y the City of ~elrn. lido abandoned or existing septic s~Tsterns were identi~aed on-site during our site investigation. E TI -F L T l'~o fuel tanks were located during our site inspectioz2 or sails work, C~lyxnpic Engineering reva.eed the latest "Z.ITT" list Leaking Underground Storage Wank) and found no listing far tlxe subject site. T6 - - ~I E i TI The praject site is lacated wi.tlxizx the. Visually River Drainage Basin per Thurston C',ounty ~ozrzprehensive 1 ap 3. ~'ro ozzr site visit there were nca signs of existing drainage swales or channels on tl2e prapased propertye There did not appear to e any significant aff-site rzznaff onto the site fro. the properties® ldazardaus zxxaterial handling ar transpartatiazx is not expected in the area tributary to tlz.e on-site detention facility. E9 - LY 1 1 -l° The prapased site does xxat lie adjacent to or eontaiia a stream an-site, therefare, it lxas not been identi.ed as a 100-year flaad hazard area. TI 8 - EST ET SI E TI tLiTiE .All disturbed pervious areas including the storm treat area will be vegetated and landscaped. SE~T~C3t~ 9 -[?QWNSTF2EAM AIV,OALY alb Final caleulatiaxxs far the praject starnxwater treatzxaent and storage systeans are included in the Appendix of this report. All starznwater rzznoff generated y site development will be treated, stared, and infiltrated an-site. In the event of a failure, starzxz water will averfla back rota the an-site catch basins aiad eventztally onto tlxe parking area. Adjacent properties sozzld xxot be affected due to failure of the proposed starmwater system. Drainage facilities including catch basins, piping, trenches/galleries, and the treatment facility will require razitine nzaintenazxce. A maintenazice agreement will be prepared. and finalized. prior to final project approval. 3 T 1 ~, C1'1 1 - S f E ~'anstructian Best cage ent Practices fB F's} will be employed to praperly Blear and grade the site and to schedule constrxxctian activities. Before any canstruction begins on-site, erasian contral facilities shall first e installed. Tlxe planned canstruetian sequence is as fallaws: ~ECTi 2 -T I G~ I E °T A stabilized constructian entrance shall be installed at the entrance to tlxe prapased project to prevent vehicles franc tracking soil away frann the disturbed areas, if sedinxent is tracked onto the surrounding public roadways, sediment shall, an a daily basis, be swept ar shoveled fronx paved surfaees and not washed 4tan into the ro~clsicle stc~rnx ciraixa~~;o syst~rrz. The eontractaz° shall. not be allawed to leave disturbed. areas greater than S,OOtI sf that are to be left un-worked. for mare than twelve ~2} hours axncovered during the 4 rainy season froaxz l~Tovenaer 1. throazg. March 3f. I~[izlclz, sodding or plastic covering will e used. to prevent erosion in these arose. Eluting construction, the contractor will also be required to install filter fabric fencing as needed, pe.r tlae erosion control plan and as directed by the Engineer, ar pity Inspector. TI - A T I T !. T TI X111 disturbed areas will e paved, covered with a building or landscaped with grass, shrubbery, or trees. CTl 4 - E T~~ IC L.YSIS `here are no slopes exceeding 15°,fo on-site, therefore, a geotechnical analysis was deemed. unnecessary, ECTI 5 -1 ~ECTI E GIB In addition to the a~orznal pity inspections, the Project Engineer shall inspect the facilities related to storan water treat ntA erosion control, storage and conveyance during cozistructioxl. t a mini aznz, the following items shall e inspected at the tinge specil"ied: I. `I'lze erosion control facilities shall e inspected before the start of clearing and grading to ensure the followizz structures are in place a. construction Entrance b. Filter Fabric Fences c. Inlet pediment Protection t~ final inspection shall be perfarzned to verify final ga°ades, settings of structures and all necessary iaaforation to complete Ezxgineer~s Cox-zstructiozz Inspection ~epcart to orzn and Goxnxnerci.~l E~gr~exzaexat to maintain storxn~ter facilities. These forms rrz.ust be completed prior to final public worl;_s construction approval.. 5 C T L F LL 1" 7 I E s ~Vasaut fra a cancrete truck shall net be dumped rota the sta drain, ar ante sail. ar pavement, which carries starmwater runaff. It can be dumped i.nta a designated area to be later backfilled ar hardened and braken up far dispasal rota a du~r~pster, 7['he ~'antractar will e required to designate wash. dawn area far equipment and cancrete trucks. 6 T" 111 I ~ 1 - l Tl= '~ha foxing pages captain maintenance Heads far anost of the camponants that are part of year drainage system, as wall as far same caxnpanants that you may not have. f.,et us knave if there era any camponents that are missing am these pages. Ignare the requirements that do Hat apply to youur systa tau should plan to camplata a checklist for all. system companaxxts an the following schedule: t. 1~~anthly fram November tlxroug .April. (Jnca in late summer ~prafarably ~apte ber}- 3. ar any major starm (use 1"° in 2d hours as a guidel~ria) items marked'"" only. fTsing phatacapies of these pages, check off the problems you baked for each time you did an inspection. .Add comments an problems found and actians taken. Leap these "Ghackad"' sheets in year files, as they will be used to ~vrita your annual rapart (due in I~~ay}. lama itaxns da Hat Head to ba baked at every time an inspection is dens. -Case the suggest frequency at the Ieft of each its as a guideline for year inspection. a~x xnay call the jurisdiction for technical assistance. 1?laasa da Hat hesitate to call, especially if you era unsure whether a situation yaax have discovered may be a prabla. 7 Ix~se~tzc~n I~eri4Cl~ AlW ~'9 1M 41~~3L' 1''~(';~s77~~59P~t1.T uyber of sheets t~tt~cl~e: date Izzsected: aasectt~r's Sigxz~t~~re; L'~ 1-~11S~lYlElV 9. t8 ,q Rt, lV 1. ~AV AJI'J P1S. \.f BAR.. ainteance Checklist for Conveyance yste s ies, Ll~tches and ~Swales} Frequency Drainage v~ Tteq'd Problem Conditions `Po Check For Conditions That Should Exist System Feature M.S. Pipes v° Sediment c~ Arcumazlated sediment that Pipe cleaned of all sediment and debris exceeds 2o4fo of the diameter debris. of l'.lze pipe. '~ Vegetation Vegetation that reduces free All vegetation removed so water may°oent of water through flows freely. pipes. ~ ~ Damaged Protectave cos#.ing us Pape repaired or replaced. gusted, beast damaged, rust is causing or eruslied) snore than 54;~o deterioration to any part of pipe. ~ ?` Azay dent that sigzsz6cantly Pipe repaired or replaced. impedes flow (i.e., decreases file across section area of pipe by more then 2t}°la)- ~ ~ Pipe has major cracks ar Pipe repaired ar replaced. tears allowing groundwater leakage. M.S. Swales `T'rash & Dumping of yard wastes such Remove trash and debris and debris as grass clippings and dispose as prescribed by County branches into Swale- Waste Management Section. Llnsiglztly accumulation of non-degradable materials such as glass, plastic, metal, foam and coated paper- ~1 Sediment Accumulated sediment that Swale cleaned of all sediment and buildup exceeds 20°!Q of fire design debris sa that it matches design- depth. ~ Vegetation Grass cover is Sparse and Aerate soak and reseed and mulch not growing weedy or areas are bare areas. Maintain grass Iseight or over-graven overgrown wik.h woody at a minimum of fi" for best vegetation. stormwatzsr treatment. Reniave woody growth, reeontaur and ~ reseed as necessary. M Conversian Swale lies been filled in or Tf possible, speak with homeowner by home- blocked by shed, cs=oadpile, and request that Swale area he owner tca shrubbery, etc. restored. Contact County to incompatible report pmlalem if not rectified lase voluntarily. A Swale does GF`ater stands in swale or A survey may he needed to check not drain flow velocity is very slow. grades. Grades need to be in T~fo `,~'tagasation accurs. range of possible, Tf glade ss less than T°,o, under drains may need to be installed. J~~ ~~~- ,~=~~Ett~, wuo4uer a prt.RUZem exasrs, pcease contact the Juris€lzction and ask fiar technical assistance. t1~i11YiL' tt A tW ~L.!V1V T A'a.S.T ) I~~Iainteance Checklist fer ate sins n inlets Frequency Drainage ~1 lleq'd Problem Conditions To Check For Conditions That Should System Feature F'exlSJt M,S General ~ Trash, Trash or debris zn front of the No trash or debris located debris, and catch basin opening is blocking immediately an front of catch sediment capacity by more than l4°!0. basin opening. Grate is kept in or on clean and allows water to IPa^aen entC'r. ~ ~1 Sedsment or dehrzs (zn the Na sediment or debris zn the laasin) that exceeds 1/3 the catch basin. Catch basin is depth frown ties bottom of basin dug out and clean. to invert of the loo=est pipe into or out of the basin. h~,S ~ Trash or debris in any inlet or Inlet and outlet pipes free of pipe blocking more than lf3 of trash or debris. its hezglzt_ I4S ~ Structural Corner of frame extends more Frame is even with curb. damage to than. 3f4 inch past sorb face flame into the street (af applacable~. azadfor tap slab M ~ Top slab has holes larger than 2 Top slab is free of holes and square inches or cracks wider cracks. than 1/4 inch {intent is to make Stare all material eS rnalmng into tkae basizt). Pal ~ Frame not sitting flush on txap Frame is sitting flush on top slab, n.e_, separation of more slab. Haan 3f=# loch of the frame from the top slab. ~1 ~~ Cracks in Cracks wader than 1J2 inch and Basin replaced ar rz'paixed to basin longer than ~ feet, any evidence design standards. Contact a xrallsl of coal particles entering catch professional engineer for laottzam basIIn through eraeks, or evahzataon. maAntenanee person audgas that structure is unsound. A ,f Cracks wider Haan lf`~ inch and No cracks mare than 1l~1 inch longer than 2 foot at the joint, o£ wide at the jcaint of any izaleUoutlet pipe or ang azxletfoutlet pipe. evidence o£ soil particles entering catch basin through eraeks. ~Q A A.~ ENT "A'> (CNTI EDP lviaitean~e f%eckhst for Hatch seine an€[ Inlets Fregztency Drainage ~ Feq'd Prolalean Conditions To ClaecR; Fear Conditians That Should l;xist ~ System Feature NI,S al Fire hazard Presence of chemicals such 1Vo color, odor, or sludge. or ether as natural gas, oil, and Basin is dug taut and clean. pollutaCa^ gasolene. C)hnoxaoxea COIOr, odar, or sludge noted. >S ~ Outlet pipe as Vegetation or roots growing laic vegetation or roat growth slagged. with in inletfoutlet pipe joints present. vegetation that is more than six inches tall and less dean six inches aparP:. A ~ Settleent/m Basin lass settled mom than Basin replaeed or repaired fa 23aldgn-m€.`nt. ~. YriCla Or ha$ rotated more desagn standards. l~ontact a Haan ~ inches oast of professional engineer for alignment. evaluation. If you are unsure whether a problem exists, please contact the ~lurasdiction and. ask for technacal assistance. (',omments: ~P~ A =Annual (1Vlarch or April preferred} I42 = Mantlaly (see schedule} S =After major storms l~ t9 taL•~J.t1YLSSiY t to A ev fLr4Jl'E 11 l.l~ 1Vlaintenance Checklist car reds {Lans~apin} ~re~uency Drainage ~ Problem Canaiti4ns t4 check k4r c4nditians That sn4%%ld exist system ~eatnre i~f i General ~ Weeds Weeds growing in snore than Weeds present in Iess than 5°fo of (nanpois4nous) 24?°f° Qf the landscaped area the landscaped area. i i (trees and sl%ruhs only). i l'/I i v tafety hazard .any presence of poison ivy or No poisonous vegetation or Otl22r p4%s4nati^a Vegetat.74n ar %nBeCt neSCS present 2n insect nests. landscapes area. M,S ~ Trash or titter fee Ponds Checklist. See Farads Checklist. iVI,S ~ Erosion Qf Noticeable rills are seen in Causes of erasion are identified Ground Snrface Iandseaped areas. and steps taken to slow downfspread Qut the water. Eroded areas are fiIled, contoured, and seeded. A Trees and ~ l?amage Lambs or parts of trees or Trim treesfshrubs t4 resters shrubs shrubs fleet are split or shape. Replace treeslshrubs broken whaeh affect more with severe damage. than 25°0 of the tot:.al fatiage of the tree or shrub. Trees Qr Sl%ri1ID,~'s that IBaVe RelBla rat, tree, mSpC'C$%ng for been blown down ar knocked injaary Co stem or roots. Replace Aver. if severely damaged. A ~` Trees ar shrubs which are P1aee stakes and rubber-coated net adequately supported or ties around. young treestshrubs are leaning over, causing for support. exposure of tl%e roots. if g*au are unsure whether a problem exists, please contact the ,lurisdiction arad asl; far technical assistance. C`,ontments: lieu A = ~.ranuaI {!larch or April preferred} M =1VIQnth,ly (see sel%edulel S =After major storms ~~ A*ASSXJ.~1~$.E BW~fR (C'}A~S.$a.'d .0_'8.t~~ IV~~intenanee Checklist ft~x° nltraica ~txxa~ Frequency Irainage ~ Req'd Problem Conditioass to Check For Conditions That Should Exist Sys#em Feature M,S General ~ Trash 8~ See Maintenance Checklist for See Maintenance Checklist for debris Ponds. Ponds. buzldazp zn pond M ~ Poisonous See Maintenance Checklist for See Maintenance Checklist for vegetation Ponds. Ponds. E M,S v Fire See Maintenance Checklist for See Maintenance Checklist for f hazard ar Ponds. Ponds. pollution G M f Sfegetatzon See Maznt.enanee Checklxs#. for See Mazntenance Ghecklast for I not Ponds. Ponds. growing ar is overgrown M ~ Rodent See Maintenance C;heeklist for See Maintenance Checklist for holes Ponas_ P®nds. M ~ Insects See Maintenance Checklist for See Maintenance Checklist for Ponds. Ponas. A Storage ~ Sediment A soil texture test indicates Sediment is removed andlor area buildup in facility is not working at its facility is cleaned so that ~ system designed capabilities or was infiltration system works incorrectly designed_ according to design. A sediment trapping area is installed to reduce sediment. transport into infiltration ama_ A ~ Storage A soil texture i:est indicates Addi#.ianal volume is added area facility is not working at its through excavation to provide drains designed capalailities or was needed storage. Soil is aerated slowly incorrectly designed. and rototilled to improve (more than drainage. Contact the City far 4ti hours] information on its requirements or regarding excavation. overtlows M v Sediment .Any sediment and debris Suing Glean out sump to design trapping area to IQ¢/'o of depth from sump depth. area bottom to bottom of outlet pipe or obstructing slow into the connector pipe. One Time ~ Sediment Stormwater enters izfiltration Add a trapping area bt= trapping area directly without constructing a suing for settling area not treatment. of solids. Segregate settling present area from. rest of facilii;v. Contact City for guidance_ M hock filters ~ Sedamen#, lay visual znspection little or no Replace gravel in rock Slter- and debris eater t7ows 4:hrough filter daring 5ieavy rain st-terms. S Infiltration J Infiltration Standing Water in Inspection Excavate bottom of trene.h as Trenches Failure Well After 48 hours after neeessarv but at least 3 feet. storm nr Qverfiovv during Replace with crushed rack_ ~. ~ +torrns Check pretreatment systems for effectiveness. Check tribsxtary area for sedzment sources. If you .are unsure whether a prohlena exists, please contact the Jurisdiction and ask for technical assistance. Comments: l~ev A =Annual {March or April preferred) M =Monthly {see schedule) S =After major storms A . ASH l`3T'°A' {~~JN`~'~ Eli) 1V~aintenanca checklist far ~los~d Retention ~~stems {Tanbs(Vaults) Freq. l3rainage v lieq'd Problem Condztions to Check For Conditions That Should Exist System Feature ill Storage Area ~ Plugged Air Clne-hal£of the cross section afa Vents apen and functioning. Vents vent is blacked at. any point or the vent is damaged,. M Storage Area ~ Debris and Accumulated sediment depth All sediment and debris Sedsment exceeds IEI~fo of the dzameter o£ removed from storage area. the storage area for 1 Length of storage vault or any point depth exceeds 15~1n of diameter. (Bxample: 72-iflxch storage tank wauid require cleaning when sediment reaches depth of 7 inches for more than If2 length of tank. A Storage Area ~ Jaiaxts Any openings ar voids allowing All joint between tanklpipe l3etweeu nxaterial to be transported rota sections are sealed. TanklPipe facility. (4Yill require SeCtflon engxneer2ng analvsxa to determine straTCt.urai stabzhty}. l-~. ~tarage Area ~F Tank Plpe Any part Of taLlk~plpe iS Dent aUt Tanklpxpe repaired ar replaced Pent (?ut of of shape mare than 10°fo of its to design. Shape design shape, (Pev-aew required. ~ by engineer to doterflnine SCructural stability). A Storage Area ~ Vault Cracks wider than If2-inch and Vault. replaced or repaired to Structure any evidence o£ soil particles design sgecificatians and is Includes entering tlxe structure througlx structurally sound. Cracks in the cracks, or Wall, maintenancelinspectian Bottom, personnel determines that the damage to vault. is not structurally sound. Frame andfor Top Slab A Storage Area ~ Cracks wider than 1!2-inch at hla cracks mare than 1?d-inch the joint of any inletloutlet pipe wide at the joint of the ar any evidence of soil particles inlet(autlet pipe. eTlter131g the Vault through tlxe walls A hlanlxole Cover l;Icrt Cover is nxissiixg or on3.y Manhole is closed. in Place partially in place. Any apen manhole requires maintenance. A Manhole 1° lacking Cddeclxanis cacxnot be opened by Mechanism opens with proper McClxaniskn one-' matnt4'nanCe }?erSQri wlt}t tOQls. I~Iot. proper tools. Dolts Into frame Working have less than ll~" inclx of tlxread (may not apply to self-locking lids>. A Manhole tit t"over tine maintenance person cannot Cover can. be removed and I>icuit 1o remove Lid otter applying reinstalled by one maintenance 1?.ernove normal Ixlt:ing pressure. Intezxt person. is to keep saver from sealing off access to maintenance. ~~ Freq. Drainage ~ 13eq'd Problem Conditions to Check For Canditions That Should Exist Systean Feature A Manhale Madder Ladder is unsafe due to anissing Ladder meets design standards. Rungs rungs, mzsalzgnent, not Allows maintenance person Safe Clnssfe securely attached to structure access. Wall, rust, or cracks. if you are unsure Whether a plslem exists, please contact the Jurisdiction and ask for technical assistance. Comments. lieu A =Annual (March or Agril preferred} AB =Monthly {see schedule} S =After major storms ~~ ECT! 2 - ESP SI LE IZ Tf the property owner shall e responsible for the operation and maintenance of all on-site drainage facilities. ECTI 3- EGET T'[t:? A E T L All disturbed pervious areas within the site will e landscaped to provide an aesthetically pleasing environment„ ECTI 4 - CE C L Warning signs ~e.g•a "Dump No waste _ Drains to ~~ronndwater") will be embossed or painted on or adjacent tc~ all. star drain inlets and will e repainted periodically as necessary. 17 appendix ~i~c~l ~°~ci,~e c~lcltir~ns FIAI.~ RINAE CUL,ATINS The following calculations were based on the zequireents contained in the SDE Storzxxwater Management Manual, IJJ edition. SIN A BASIN IN TI N SLT '~ ~. `€~'- ~''~'~ ~: x~ 1, ~ ~ ~ ~ ~ 3rd `~ ~ R `~~~ ~ "~` ~~ k ~ ~ ~ ',ti ~r ~ '~~ ~. .~ `;Rn ~. ~.xk. ,~i. 'a ~,., a,:.~. ~, 's ,.,.,. .,. Cw~`,~: .i'_.~ , ~..~~ ~, aw., F,.,, ~M ~., +*},„~aa ;,xk ~ ? `~ ° ,s~ "~ , ~. ' fix . ^ '`~ , ~ . . . , . .., ., .. .. ._ . , ., . .,, . ,. ,.,.. i .v.. . Sub-basin A Total Impervious 0,J p,~g FarkinglSidewalk Impervious Roof Area 0.22 Q,~ Disturbed Pervious 0.12 p,1 Total 0.83 Sail (;lssificatio: SCS Soil C'lassificatione Spanaway C:ravelly Sandy I~oaxn Hydrologic Group: A Design Infiltration Hate: 0"Ilzr A U I C CLATIC)S ini um Stormater Treatment ea egaiire Sto Shed software was used to model the runoff from the on-site parking and sidewalk areas. The 6-month stczrm errant resulted ixx a ilo~v rate of 0.13 cfs. The 140-year flow rate i.s 0.73 cfs. Per the General LTse .Bevel Designatian far Pretreament (TSS) for ontech Storxnwater Solutions, Inc. Vorteclas System provided y DQE, dated November 19, 2003 (updated May 2006), a orteclis odel 1000 vault will be needed for this application. The Model 1000 vault will provide adequate stormwater treatment up to 0.55 cfs with a 100-year pe~.k flow treatment capacity of 1.6 cfs. ATE UANI CU TI S 15 Storin'I'eeh ~haxizbers: Stare ~~olume wf 12" Stone Dase ~~ 12" Pex•izneter (30°f~ void ratio): ~15)(d5.9 cf(chaxner} = 688 of = 534 cf 7'otcrl Star°age Tfolzrre rovzc~ed = , 222 ra f a ~'S ~ c .: t? Active ~olxxzne = 657 cf {see attached StorShed software output) our raw o X30' x 15.75')(20 ~n/hr)(1>/12"~(4S ~Caursj = ~t,10 ~f > 1 c . ~ 4?K 4 Ul~TQ Hoof r~znoff w~Il e tzgtline to the ~fa~tx°~tiox~ gallery. aG-740 Quantity Calculator Praject ame Yelm Rfaza Project 1~6umer #fQ5Q26 F'raject t_ocatian 1°efm i0aluma in chambers Volume of axcavatian Amount of stone Voiumo in stone Amount of Filter Fabric 8~umber of Chambers Number of l^nd daps Aaunt of Mane Amaunt of Filter Fabric Ivan- even Isalatar Raw even Isafatar Raw 689 cf 2,968 cf (system only - net total excavatfon~ 1,780 cf 6 car 534 cf 1,925 s (not include lsalator Row) Total Storage Volume 1,222 cf £~iypic Engineering Vista Green Piat p50Ct9 star it -- asi .vent u E3asinlC~ Peak Peak T Peak ifol rea ethod Event ------- {ef) {hrs {ac-ft) ac floss gas€n A - wc~ .~ a s.ao 0.0~3~ a.4s sCSOSC~ rains a rea. asi yd Method: SCS Unit 1-iyd Peak Factor: 484e00 Storm [fur 24.00 hrs Area CN Pervious 0.0000 ac 86.00 impervious 0.4900 ac 98.00 Total 0.4900 ac Supporting Rata: nnpervias C Data: Impervious parking sidewalk 98.00 I~eious l°G Rata: Flow type: Qescription: Fixed None Entered Irnpei®US TG Rata: Flow type: Description: Sheet Parking Sidewalk Channel PVC Pipe flaw 1teC_ Ua~lt -- '~ - ear rainae rea: sin ~iyd Method: SCS Unit Flyd Peak Factor: 484.00 Storm Dur 24.00 hrs Area CN Pervious 0.1200 ac 88.00 Impervious 0.7100 ae 98.00 Total 0.8300 ac Supporting Rata: Pervious ~ Rata: Pervious Landscaping 38.00 pervious CN Data: Impervious parking, sidewalk, roof !'ervious TC Data: Flaw type: Description: Sheet Landscaping 1 pervious TC Rata: ~tosmShed 2f24/2007 F~aintype TYPE1A 6 mo Lass ethod: SCS CN Number SCS Abs: 0,20 TG 0.00 hrs 0,06 hrs 0.4900 ac Coeff: Travel Time 0.1000 0.10 min Coeff: Travel Time OA100 2.01 min 25.0000 1.56 min Peak 4'0l Area ethod F2aintype 0.1200 ac 98.00 0,7100 ac Length: Slope: Coeff: 15.00 ft 2.00°/a 0.1500 Travel Time 2.72 min 1 of 3 C?lympic ~ragineering Vista ~reerD Plat StormShed #45049 212412407 Flow type: Description: Sheet parking, sidewalks Channel roof Channel PVC Pipe flow Length: Slope: 134.00 ft 1,50®l0 150.00 ft 1.00°/Q 165,00 ft 0.50°la Coeff: Travel Tme 0.0100 2.01 min 25.0000 1.00 min 25A000 1.56 min af'r atl~l~ LPD PUTE [LI'] SU Y 100 yr MatchC~=PeakQ= 0.7206 cfs Peak C?ut (~: 0.3998 cfs - Peak Stg: 343.78 ft Active Vol: 657,45 cf a e~ao of aI L. Gaol sate rject reci s E2 yr] 2.00 in ~5 Yr~ 2,50 in [10 yr] 3.00 in [100 yr~ 4.00 in ~6 mo] 1.28 in rains rea: asin Nyd Method: SCS Unit C-lyd Peak Factor: 484.00 Storm Dur 24.00 hrs Area CN Pervious 0.1200 ac 88.00 Impervious 0.7100 ac 98.00 Total 0.8300 ac Suppartirtg Data: Pervieus CN Data: Pervious Landscaping 88.00 Irtaervir~us CN Data: Impervious parking, sidewalk, ~ roof P"erviaus ~'C Data: Flow type: Description: Sheet Landscaping Irnpeiaus TC Data: FIo type. Description: Sheet parkingp sidewalks Channel roof Channel PVC Pipe flow Loss ethod: SCS CN Number SCS ,4bs: 0.20 TC 0,05 hrs 0.08 hrs 0.1200 ac 98.00 0,7100 ac Length: Slope: Coeff: Travel Time 15.00 ft 2.00% 0.1500 2.72 min Length: Slope: Coeff: Travel Time 134.00 ft 1.50°l0 0.0100 2.01 min 150.00 ft 1.00% 25.0000 1.00 min 165.00 ft 0.50°la 25.0000 1.56 min 2ot3 4?6ympic Engineering Vista ~r€:en Fiat #45009 ~ .EST '~ [100 yr ottt] Ls~E i-f~dlQ Peak F'E=a14 T F'Ba V4~I _____-- ~cfs~ ~hrs~ (ac-ftj `t44 yr out 4.44 8.25 4,2495 ST'ORLIST [Infiltration] E.STEI~® e I : in~ftratio Gont Area ac} 4.s344 d3esc: lnfiitration Gaiiery Mart El: 341.5000 ft ax ~I: 345.5000 ft Gontrib I~asin: Contrib Flyd: Length idt Void Ratio 39.0000 ft 15.7500 ft 30.00 iSCLiST [Infiltration] LsaTEN ontrol tractors 1 : tfiltratio - Infiltration control structure C~escri: Infiltration Gallery Mart EI 1Viax EI Increment 341.5000 ft 345.5000 ft 0.10 Infil: 20.00 infhr caltilir: 1.00 StormShed 2!2412447 3 of 3 ESE USE VEL IAN N °~ EA ENT (TSS) r C` N'TC Star vwtr Solutions nc. ~c~rtec s~ yste Ap licat: ~'I~ITE~I~ Sto awater Soltrtions Inc., anufacturer and Vendor Applicant's Address. 12021 NE t~itort ~Vay Portland, C~I-~ 97220 A licatit~n oc ents4 Applicant's Perfor ante ~iain~s. used on laboratory trials, the Vortechs System will achieve a~a 80°f~ TSS removal efficiency for sediment particles ranging from 38 to 7S microns at an operating rate of 13 gallons per minute per square foot (tsPl~il!sfj at the peak flow far the Ecology design. treatment storm. The systean is recommended only for sites likely to produce relatively high TSS concentrations (above t00 mt;/L), where TSS is primarily composed of ~0 rr~icrons and. larger. Potentially appropriate sites include parking lots, laigh~vays and urban streets, material transfer sites, hydrocarbon transfer sites, retrofits, steeplerosive sites, and space-lir-nited sites. Tec ial evie tom ittee~s eco endatlon: 'The ~ finds that-. The Vortecs system, sized at 35 G fs4 should rovide3 at a minimum, equivalent performance to a resettling basin as dezaed in the most recent ~tr~rnzwater anagernerzt ~arzual for ~Yest~r~tz czshz~tr~rr), '~lurtze ~; ~`apt~t° ti. Findings of Fact: Technology escrz .Lion: ~l)-RC) of Vortechs System Technology Repoz~t, dated June 2003, may be requested from CC3TEC Stornzater Solutions inc. Design Manual and technical bulletins can be downloaded from company's ~veb site. sC~a~tact Infor ati~~m A~pplaeant Contact: ticant wesate: ~~O~oc°~' iVe~ ~1n~: Sean I~arc~F (800} 548-4667 darc~s~~contech-ci.corr~ ~~1~u 4t.C~3Ilt~C~1~t4?T[11V~'~~~'.GC1~1 att~°ll~~; ecy ova ?o~frc~ ~r~arn~1~~Fc~fstorrwaterle~~tecr`index ht geology: zeke o~ap~n ~Tater t~ality rograrr~ (360 407-6435 rr~o461 L ~cy..;ov itsa County (360) 337-7292 dtucer~~r,co.katsap.~a.us .~4ppe~~c~i ~ pails e~°t 1 S C Ct ~' Y` 1 P S S its es: X202 ~ S7 a rce u er.221 3 re are or. car s ~: rs, L,T..: PE LIB ENS EE .ICE C TI T E L ITE I I v ~`~ ~. . tL 1 ~ 2: tL L 1 orz A Buv~ C1 C2 '7 g''^'~+ LaCial VNt'Y`Y a+Fh T'~1d ~.F °c "' 4 "S ~U98 (. LVt\.IlEN E ~V.~4 { ER QE~ i w 1 T~.f ~ P`ER{fIV VE.J a'.. ~0.d\.fEL NELFVJ. DEr T ~E~. 120" Greater than bottom of hole Nearly Leuel 13. FINDINGS REGflMEDATLtONS: Static water Leuel oyes 120" below the existing grade. Use a design infiltration rate of 20 inlhr or Less for drainage infiltration facilities Located in the G2 horizon soils. C?__ e~th Coiar ~'eure 0"- 24" 10YR2f7 GrYFSa~m 24"- 32"' 10YFt4f~ GrVFSaLm 32"- 34" ~ OYR4t6 VOrLmSa 34"- 6f" 10YRSJ4 ExGrCSa many stanes 67"-'i56" 30YE2061 ~xGr&Cab CSa same stanes Sails Strata es~riptica~ Soil L.~ #~1 °kCL °loORO ~F SCR MOT IND CEM ROO ~7C> FSP °~20 <5 <9S 1S~K _ _ ff 2-6 2 X20 - <2 a i SSK - - - ff 2-6 3 <10 - <55 SCa - - - - 6-20 6 ~c1 - <00 SG - - - - >20 >40 reviaic~ns Textural lass trctre ra es ~f Structure (Textured (T Cobble -Cob Granular ~- r Stron - Stoney - St lucky - iky oderate - Graveily - Gr Platy _ Pi eak - 1 Sand _ Sa assive - as Loamy - Lm Single Grained - SG Slit - Si Sub-An uiar Block - S Clayey - Ci Caarse _ C Ve - !l Extremely - Ex Fine F ediurr~ - ~> - veneralized range of infiltration rates from SC; soil survey {~X>) FSP -Estimated Field Saturated Percolation rate based on horizon specific factors. I t I I T T rairie laz Test gate ~~~2 alete B illiam Parnell, l~.E. PE Jab #t361 QO l~t1LE RING IFIL.T TIQ TEST Test Hale 1 (test run 7" below existing ground surface ~ Mart Sta Ela sed Tune Total Dra lrafiltratian Rate ( in) ( n) i { in (inches } (ln1r ) / j ii JF t!4" ' `i^ e' 11 tJ q r sp Gt° C ~ y 9 a .} ` i 'i ~ g d ,. /L /" j R ry " 'tp ,, qq q g^ y}'~ ~ f C ^ sue' F ~" .G f' S.lll" ' °#®'. V GL.f~ ~1penix III iii p '~ ~ ,~ ,®. w ~ ~ w ~~ Q~ ~~ cam ~ ~ ~ ~ cn+~ ~~ ara r, ~ ~ ~~ ~ ~. ~ cv cv ~ S 0 0 ~ u., a, n ~ ~ ~-, ~~ o ~' ~ 1~?~e~~c~ix ~~' ~yMc~inc~,~e ~c~sin l~fiap -.-- ~ s= z i+ /~r %~. ~~ ^ ,~ ., ;' ,~ n ~~ ~ ~~ ~ ~ c`v c.6 ~ ~ ~~ ~~ Q w ~°o c°o a *~' ~ "~~' °inN ~;_~~~ ~ . r~, ~u ~: ~~. ~: ~~~r