5.2. SR 08-08-2011 - Laserfiche WebLink

Home Browse Search

preserve the existing natural features, and to provide water quality protection to meet State nondegradation requirements in addition to City and other local requirements. E7. Storm water will be required to be pretreated prior to discharge to wetlands. E8. A Storm Water Pollution Prevention Plan (SWPPP) in conformance with the NPDES regulations will be needed for any development in the study area. Review of the SWPPP for each development will be required by the City. F. Wastewater Mitigation Plan F1. Under all three scenarios wastewater generator from the study area will be conveyed north through existing 15-inch and 18-inch trunk sewer lines along Twin Lakes Road and then west through the 24-inch trunk sanitary sewer to the TH 169 Lift Station. F2. Under all three scenarios, the existing collection system, including the TH 169 Lift Station, and the WWTF have existing available capacity to handle the additional projected flows from the AUAR Study Area. However, under Scenario 3, 85% to over 90% of the capacity of sections of the existing trunk sewer system along Twin Lakes Road from 179th Avenue NW to 171St Avenue would be utilized during estimated peak hour flow conditions. Also under Scenario 3, approximately 97% of the current pumping capacity of the TH 169 Lift Station would be utilized during estimated peak hour flow conditions. F3. Wastewater from the portion of the study area on the west side of TH 10 could be conveyed north through a new sanitary sewer line constructed along the west side of TH 10 and connected to the existing 15-inch sewer that crosses TH 10 just north of 170th Avenue. Under Scenarios No. 1 and No. 2 a 10-inch diameter gravity sewer line would have sufficient capacity to carry the projected peak hour wastewater flows from the portion of the study area west of TH 10, plus potential flow from future development south of the study area. Under Scenario No. 3 a 15-inch gravity sewer line would be required. For Scenario No. 1 a 10- inch diameter sewer would be recommended to serve the area along the west side of TH 10. For Scenarios No. 2 and No. 3 a 15-inch gravity sewer line is recommended for carrying the projected flows from the portion of the study area west of TH 10 to allow for potential future development south of the study area. F4. Wastewater from the portion of the study area between TH 10 and the Burlington Northern Railroad could be conveyed north and connected to the existing 15-inch sewer just south of 171St Avenue that extends north to 173rd Avenue. For all three scenarios, a 10-inch gravity sewer would be large enough to convey the estimated peak hour flow from the portion of the study area between TH 10 and the Burlington Northern Railroad. However, because the current urban service area boundaries extend beyond the limits of the study City of Elk River Draft Alternative Urban Areawide Review July 2011 Page 12 of 84