Agenda - Environmental Policy Board - 07/20/2009 - Special Meeting

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General Criteria The following general criteria should be used when designing the sediment pond. . For basins intended to have permanent water levels, a minimum of 4 feet of standing water (dead storage depth). . Maximize the separation between inlet points and outlets to prevent short-circuiting of storm flows. . A 10:1 slope for the first 15 feet from shore, then 4:1 maximum slope. Floatable Pollutants D. the establishment of design criteria for stormwater outlet structures to address floatable pollutants and to provide for access for maintenance and repair; During the project review, the WMO may determine that a pond skimming device would be required. Pond skimming devices should be designed to remove oils and floatable materials up to a I-year frequency event. The skimmer should be set 6 inches below the normal surface water elevation and should control the discharge velocity to 0.5 fps. Nutrient Trapping Pond Design E. pond design methodology for nutrient entrapment consistent with the subwatershed goals; and See Pond Construction Pollutant Loadings for Watersheds F. compliance with pollutant loadingfor specific subwatersheds consistent with local, regional, and statewide plans in consideration of Pollution Control Agency water quality standards. . At this time there are no target loads for watersheds in the WMO. The LRRWMO will work with the Anoka Conservation District in addressing the impairment of the Mississippi River from the northwest city limits of Anoka to the Rum River and the Anoka Conservation District and the Upper Rum River WMO in addressing the impairment of Rogers Lake. Water Management Plan P:\Mpls\23 MN\02\2302047\WorkFiles\3rd Gen WMP\LRRWMO _3rd Gen WMP _July 2009 _Draft.doc 83