Agenda - Planning Commission - 02/02/2006

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specifications including access for operations and maintenance. Basin discharge rates must also be controlled to prevent erosion in the discharge channel. a.) The applicant is required to obtain a National Pollutant Discharge Elimination System/State Disposal System CNPDES/SDS) construction storm water permit from the Minnesota Pollution Control Agency for any project that disturbs five (5) acres or more of land. 3.) For disturbed areas less than five (5). acres sedimentation basins are encouraged, but not required, unless specifically required by the city engineer. The applicant shall install erosion and sediment controls at locations directed by the city. Minimum requirements include silt fences, rock check dams, or other equivalent control measures along slopes. Silt fences are required along channel edges to reduce sediment reaching channel. Silt fences, rock check dams, etc. must be regularly inspected and maintained. Sediment basins related to impervious surface area. Where a project's ultimate development replaces surface vegetation with one (1) or more acres of cumulative impervious surface, and all runoff has not been accounted for in a local unit of government's existing storm water management plan or practice, the runoff must be discharged to a wet sedimentation basin prior to entering waters of the state. I.) At a minimum the work must conform with the current version of the Minnesota Pollution Control Agency's publication, "Protecting Water Quality in Urban Areas," and the current requirements found in the same agency's NPDES/SDS permits for storm water associated with construction activities. Generally, sufficient silt fence will be required to hold all sheet flow runoff generated at an individual site, until it can either infiltrate or seep through silt fence's pores. Temporary stockpiling of fifty (50) or more cubic yards of excess soil on any lot or other vacant area will not be allowed without issuance of a grading permit for the earth moving activity in question. For soil stockpiles greater than ten (I 0) cubic yards the toe of the pile must be more than twenty-five (25) feet from a road, drainage channel or storm water inlet. If such stockpiles will be left for more than seven (7) days, they must be stabilized with mulch, vegetation, tarps or other means. If left for less than seven (7) days, erosion from stockpiles must be controlled with silt fences or rock check dams. Draft StormWater Ordinance Page 10 of 20 January 20, 2006 05