(A) General. No SWPPP which fails to meet the standards contained in this section shall be approved by the City Council or issuing authority.
(B) Site dewatering. Waters related to dewatering or basin draining must be discharged to a temporary or permanent sediment basin on the project site unless infeasible. If discharging to a sedimentation basin is infeasible, it must be treated with appropriate BMPs such that the discharge does not adversely affect the surface water or downstream properties. All discharge from dewatering activities must be done in a manner that does not cause erosion, scour, or flooding.
(C) Construction site waste.
(1) Solid waste. Collected sediment, asphalt and concrete millings, floating debris, paper, plastic, fabric, construction and demolition debris and other wastes must be disposed of properly and must comply with MPCA disposal requirements.
(2) Hazardous materials. Oil, gasoline, paint and any hazardous substances must be properly stored, including secondary containment, to prevent spill, leaks or other discharge. Restricted access to storage areas must be provided to prevent vandalism. Storage and disposal of hazardous waste must be in compliance with MPCA regulations.
(3) Liquid waste. All other non-storm water discharges (concrete truck washout, vehicle washing, maintenance spills and the like) conducted during the construction activity shall be managed and disposed of in a way that will prevent discharge to the municipal storm sewer, wetlands, natural drainageways or waters of the state.
(D) Erosion prevention practices.
(1) Channelized runoff from adjacent areas passing through the site shall be diverted around disturbed areas, if practical. Otherwise, the channel shall be protected as necessary to prevent erosion. Sheet flow runoff from adjacent areas shall also be diverted around disturbed areas, if practical. Diverted runoff shall be conveyed in a manner that will not cause erosion, scour or flooding.
(2) All activities on the site shall be conducted in a logical sequence to minimize the area of bare soil exposed at any one time.
(3) Stabilize exposed soils, including stockpiles, whenever it is known that land disturbing activity will cease for 14 days or more. The stabilization must be initiated immediately and completed within 14 days.
(4) Stockpiles must be located outside of buffers and storm water conveyances and have effective sediment controls in place to prevent discharge. For soil stockpiles greater than ten cubic yards, the toe of the pile must be more than 25 feet from a road, drainage channel, or storm water inlet. If such stockpiles will be left for 14 days, they shall be stabilized by mulching, vegetative cover, tarps or other means. If left for less than 14 days, stockpiles shall be controlled by placing effective sediment controls around the base of the pile. In-street utility repair or construction storage piles must be covered with tarps or suitable alternative control and storm drain inlets must be protected with an appropriate filtering barrier.
(E) Sediment control practices.
(1) Perimeter controls. Establish sediment control BMPs on all downgradient perimeters of the site and downgradient areas of the site that drain to any surface water, including curb and gutter systems.
(2) Inlet protection. All storm drain inlets shall be protected during construction until final stabilization has been established or until approval from the city.
(3) Vehicle tracking. Vehicle tracking of sediment from the site must be minimized by BMPs such as rock construction entrances, track pads, wash racks, or equivalent systems. Vehicle tracking of sediment onto paved surfaces must be removed by street sweeping as needed to prevent discharge of sediment laden water from entering the city storm sewer system.
(4) Buffer. Maintain a 50-foot natural buffer or, if a buffer is infeasible on the site, provide redundant (double) perimeter sediment controls when a surface water is located within 50 feet of the land disturbances and storm water flows to the surface water. Redundant perimeter controls must be at least five feet apart unless limited by lack of available space.
(Ord. 2005-04, passed 3-22-2005; Ord. 2020-09, passed 4-14-2020)