Agenda - Council - 06/12/2018 - Laserfiche WebLink

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Information contained in this SWPPP narrative sheet summarizes requirements of the GENERAL PERMIT AUTHORIZATION TO DISCHARGE STORMWATER ASSOCIATED WITH CONSTRUCTION ACTIVITY UNDER THE NATIONAL POLLUTANT DISCHARGE ELIMINATION SYSTEM/STATE DISPOSAL SYSTEM PROGRAM - Permit No: MN RI00001 as they apply to this project. All provisions of the permit including those not specifically cited herein shall apply to this project. The Contractor is responsible to be familiar with and comply with all conditions of the permit. The full text of the permit is available at: http://www. pca.state. m n. us/i ndex. ph p/water/water-types-and-programs/stormwater/construction- stormwater/m pca-to-re-issue-construction-stormwater-genera l-permit. htm I SWPPP AMENDMENTS Permittee must amend SWPPP as necessary to include additional requirements to correct problems identified or address the following situations. 1. There is a change in design, construction, operation, maintenance, weather or seasonal conditions. 2. Inspections or investigations by site owner or operators, USEPA or MPCA officials determine the SWPPP is not minimizing discharge of pollutants to surface waters or underground waters or discharges are causing water quality standard exceedances. 3. The SWPPP is not achieving the objectives of minimizing pollutants in stormwater discharges associated with construction activity, or the SWPPP is not consistent with the terms and conditions of the permit. 4. The MPCA determines that the project's stormwater discharges may cause, have reasonable potential to cause, or contribute to non -attainment of any applicable water quality standard, or the SWPPP does not incorporate the applicable requirements of the permit. EROSION PREVENTION PRACTICES The location of areas not to be disturbed must be delineated on the project before site work begins. Disturbance on steep slopes (>33.3%) shall be minimized. Where required, techniques such as phasing and stabilizing practices designed for steep slopes shall be used. All exposed soils must be stabilized as soon as possible, but in no case later than 7 days after the construction activity has temporarily or permanently ceased. For public waters that have been promulgated "work in water restrictions" during fish spawning time frames, all exposed soil areas that are within 200 feet of the water's edge, and drain to these waters must complete stabilization within 24-hours during the time period. Stormwater conveyance channels shall be routed around unstabilized areas. Erosion controls and velocity dissipation devices shall be used at outlets within and along the length of any constructed conveyance channel. The normal wetted perimeter of all ditches or swales, including storm water management pond slopes, that drain waters from the site must be stabilized within 200' of any property edge or discharge point, including storm sewer inlets, within 24 hours of connection. Stabilization of the remaining portions of any temporary or permanent ditches or swales within 7 calendar days after connecting to a surface water or property edge and construction in that portion of the ditch has temporary or permanently ceased. Temporary or permanent ditches or swales used as sediment containment during construction do not need to be stabilized during temporary period of use and shall be stabilized within 24 hours after no longer used as sediment containment. Mulch, hydromulch, tackifier, or similar practice shall not be used in any portion of a temporary or permanent drainage ditch. Refer to erosion and sediment control plan for temporary and permanent stabilization measures for ditches and swales. Stormwater discharges shall be directed to vegetated areas where feasible. Velocity dissipation devices shall be used at discharge point. Phased construction will be used to extent practical or as indicated in the plans to minimize exposed soils. Rapid stabilization shall be of type and quantity indicated in the project specifications. Additional rapid stabilization may be necessary to minimize erosion throughout the duration of the project. Type and quantity shall be determined by the engineer or inspector prior to installation. In extreme cases, the contractor shall use any available rapid stabilization to immediately mitigate erosion, then further remedy the situation with approval by owner or engineer. SEDIMENT CONTROL PRACTICES Practices must be established on all down gradient perimeters and be located up gradient of any buffer zones. Perimeter controls must be in place before up gradient land- disturbing activities begin and shall remain in place until final stabilization. All sediment controls practices shall be re -installed if they have been adjusted or removed to accommodate short- term activities and replaced immediately after the short term activity has ceased. Short term activities shall be performed as quickly as possible. Sediment control practices shall be re -installed even before the next precipitation event if the activity is not complete. All storm drains must be protected by appropriate BMPs during construction until all sources to the inlet have been stabilized. Inlet protection may be removed for specific safety concerns identified by the Permittee or jurisdictional • 9olton & Menk, Inc. 2018, A11 Rights Reserved H2RAMS\R16114473\CAI) \114473C201._S W PPPdwg.dwg 3/16/2018 12:54 PM City of RAMSEY authority. The removal shall be documented in the fence or other effective sediment controls and shal Vehicle tracking BMPs shall be installed to minimize be approved by engineer prior to commencement c tracking BMPs are not adequate to prevent sedimei Soil compaction shall be minimized and topsoil shal dictate soil compaction or topsoil stripping. A 50 foot natural buffer, or redundant BMPs (wher( is located within 50 feet of disturbance activities an If polymers, flocculants, or other sedimentation tre, sediment controls shall be sowed prior to chemical expected turbidity, pH, and flow rate of stormwatei used with accepted engineering practices and dosin TEMPORARY SEDIMENTATION BASINS The temporary sedimentation basin shall be constri acres draining to a common location. Temporary sedimentation basins are required prior when 10 or more acres of disturbed soils drain to a "storage below the outlet per acre drained. If hydra basin must provide a storage volume equivalent to feet per acre drained. The temporary sedimentatia with the start of soil disturbance up gradient of the prevent short circuiting. The outfall shall be designs the pond for maintenance activities, and have ener, Temporary sedimentation basins shall be situated c be designed to avoid draining wetlands, unless the i Excessive sediment -laden water that is not properly DEWATERING AND BASIN DRAINING Turbid or sediment -laden waters related to dewate permanent sedimentation basin on the project site discharge to surface waters if the basin water has b obtained in the basin and that the nuisance conditi( adequately protected from erosion and proper vela All water from dewatering or basin -draining activiti conditions, erosion in the receiving channels or on ( significant adverse impacts to the wetland. If filters with backwash waters are used, the backm beginning of the treatment process, or incorporate( water may be discharged to sanitary sewer if perms POLLUTION PREVENTION Building products that have the potential to leach p by an effective means designed to minimize contact Pesticides, herbicides, insecticides, fertilizers, treat Hazardous materials and toxic waste must be props discharge. Restricted access storage areas must be Solid waste must be stored, collected and disposed Portable toilets must be positioned so that they are must be disposed of properly in accordance with M Discharge of spilled or leaked chemicals, including f unloaded shall be prevented using drip pans or abs( discharged materials and that an appropriate dispo. Exterior vehicle or equipment washing on the proje the washing area shall be contained in a sediment t washing activity must be properly disposed of. No liquid and solid wastes generated by concrete and c effectively contained. Liquid and solid washout wa! designed so that it does not result in runoff from th to each washout facility that requires site personne washout wastes. INFESTED WATERS: MN DNR permits are not valid for work in waters th Infested Waters Permit or written notification has t required. There is no exception for pre-existing pen BOLTON 75 & MENK