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•I shall bc shown on lhc plans. lf thc proposed accesso��� cyuipmcnt building �vill bc built o��cr any <br /> portion of the ponded arca, tlien adversc effccts ta thc trcatmcnl facility �vill result. Thc treatmcnt <br /> facility arca has already been modificd and cnhanccd to ihc maximum extent mcaningful, vid <br /> mitigation of additional impacts by furthcr modification or cnhanccmcnt of thc arca would not mcct <br /> City standards. Thercfore, if this project will adverscly aCfect thc pondcd area, then thc csisting <br /> ponded area must Ue rcplaced by another storm�vater treatment facility that mects City standards. <br /> 7. Thc only typc oC faciliry Uiat would mcet current City stomi�vater trcatment standards for this sitc, <br /> and that would not Ue adversely impacted by the proposed cquipment placement, is a StomiPiltcr <br /> manufacWred by Storni«�ater Management Inc. To replace the pondcd area, the applicant would bc <br /> requircd ro design and install a StormFiltcr, meeting City standards, anywhere bet�vecn thc outlet <br /> from the detention system and the discharge from the ponded area to Narbeck Creel:. <br /> 3. A StonnFilter designed and installed to replace the ponded arca must meet the following criteria: <br /> 1) The StormFilter mus[ treat the primary discharge from the existing delention system that <br /> flows to the ponded area. <br /> Z) The StormFiller cartridges shall Uc designed with a maaimum (low ratc of 7.5 gpm per <br /> cartridge. Flows exceeding 7.5 gpm shall be bypassed around the system. <br /> 3) The StormFilter media shall target dissolved pollutants and nutrients, in addition to total <br /> suspended solids. As mure effective media becomc availaUle in the future, the StormFilter <br /> shall be upgraded, during routinc cariridge replacement, to utili2e these improved mcdia. <br /> 4) The StomiFilter shall be designed with a minimum of 2.3 fcet of hcad differential Uchvicen <br /> tlie inverts of thc inlet and outlet of tl�e filter. Downstream hydraulic calculations will be <br /> performed to demonstrate that downstream condilions will not reduce the hydraulic <br /> potential across the filter duc to back�vater effects. <br /> 5) Routine maintenance of the StottnFilter is required. A detailed operation and maintenancc <br /> plan Cor the systcm must be prepared for approval Uy the City. A certificate of system <br /> maintenance musi�e submitted to the City annually. <br /> G) Maintenance and operation of the StorniFilter on ihis site shall Ue adapted, in thc future, to <br /> rcflect the current knowledge regarding Uiis emerging technology. <br /> 7) All other applicable, :md non-conflicting criteria in the current edition of SMI's Product <br /> Design Manual shall bc follo�ved in thc desil,n, construction, and maintenance of'thc SMI <br /> StorniPilter on this si,c. <br /> 8) IIecause the Storn�Filter would be located downstrcam of a detention system, the SMI <br /> mass loading design procedure, with the following assumptions, would be requircd: <br /> a. TSS removal required = 80"/0 <br /> U. VU = tlie volume of dcad storagc plus the 7-day average live sloragc volume from <br /> the routing of thc G month, 24-hour stonn through thc detention systcm (if a 7- <br /> day routing is not available, use Vb = volume of dcad storage) <br /> c. Vr= the nmoff volume from the mean annual stonn (use precipitation ��ohuuc of <br /> 0.48 inches) <br /> d. Depth of water in basin, H =depth of Vb <br /> c. Mcan annual rainfall = 37 inchcs <br /> C Pcrcent runoff capturc= 90"/0 <br /> �� <br />