Laserfiche WebLink
I' <br />QtllC( De,s;ig;n Cooskk;;r:atiom <br />Do not locate oo fill sites ex oo or near steep slopes if is expected lha! much of the water will e:ut through the <br />bottom, oc mooify the boo.om to pre vai t excessive infiltrati oo. <br />Energy dis.siparioo at the inlet to roi uim i zc: erosion <br />Ve gctate the slopes and bouom for the same reason <br />Freeboard of 1 foot <br />Side slopes of at le.a.st 2: 1 unless vertical retaining walls are used <br />lncoq,orate bypass or ovcrf1 ow for large events <br />ProVldc dedicated access to the basin bottom (rninirmnn 4: 1) for maintenanee vehicles <br />With a riser structure, include an anti-vor1ex device and a debris barrier. <br />Maintc;nance <br />Cood.oct i:nspect.)oru; semiannually and aha e.acb significant storm. Remove floatabl.es and cmcct ems ioo problems in <br />the pond slopes and boo.om. Pay particular au.entioo ID the outlet control orifice{s) for sign.s of clogging. If the orifice is <br />located in a Type: 2 catch basin, remove sedi:mem.s if they are within 18 in. of tbe orifice plate. <br />REFERENCES <br />Austin (City of), l 9 8 8, '"Environmental Criteria Man~". <br />Galli, J., pers. comm., Metropolitan Washington Council of Govermnents <br />GKY, 1989, MOutlet Hydraulics of Exteoded Detention Facilities", for the Northern Virginia Planning District Commis- <br />sion <br />-Iartigan.. P., pen. comm., Washington Department of Ecology (formally with tbe City of Austin) <br />Me tropolJ tan W a.s.hin g too Council of Govcmmen ts(MW COG), 1983, "'N atioo wide Urban R uooff Program Po ii u tion <br />Ran oval Capability of Urban Best Manag = eo t Practices in the W a.shin gtoo Metropo titan Area", available from NTIS, <br />PB84---245497. <br />Northern Virginia Planning Di.strict Commission (NVPOC), 1987, MBMP Hanclbccl:: for the Occoquan Watershed" <br />RandaR C. W ., et aJ ., 19 82, MUrban Runoff Pollutant Removal by Sedimenta tfoo", in Proceedings of the Conf ereoce oo <br />Storm war.er Deteo tioo Facilities, Henniker, NH, ASCE, pp 205-209 <br />Urban Drainage & Flood Control District, Denver, Colorado, "Urban Storm Drainage Criteria Manual -Volume 3 -&st <br />Management Practices -StomJwater Quality", Septanber, 1992. <br />\1/hippk, W. and J. HlIDter, 1981, uScttle.ability of Urban Runoff Pollution", J. Water Poilutioo Cootrol Federatioo, 53 <br />(12): 1726-1731. <br />Municipal Handbook 5 -41 11113192 -D R A F T