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1 Stormwater Quality Plan NR216/NR151 TSS Reductions City of Middleton NPDES The Phase II rule of the Federal National Pollutant Discharge Elimination System (NPDES) storm water program extends to small municipal separate storm sewer systems (MS4s) including all municipalities with a population of 10,000 or more. In Wisconsin, the DNR is the EPA designated permitting authority. Phase II permits in Wisconsin, will be issued according to the procedures established in proposed revised rule NR 216 and must meet the standards in sub. 3 of NR 151. ---PAGE BREAK--- 2 NPDES 1. Public education and outreach 2. Public involvement and participation 3. Illicit discharge detection and elimination 4. Construction site pollution control 5. Post-construction stormwater management 6. Pollution prevention (“good housekeeping”) To comply with NPDES rules, Middleton must develop and implement a storm water program that includes all of the following areas: NR216.06(2) Minimum Control Measures NPDES NR216.06(6) Pollution Prevention NR151.13(2)(b) Program The standards outlined within these two chapters require that regulated communities, including the City of Middleton, achieve: • A 20% reduction in total suspended solids in runoff that enters waters of the state as compared to no controls by 2008, and • Implement management practices to achieve a 40% reduction in total suspended solids in runoff that enters waters of the state as compared to no controls, by March 10, 2013. ---PAGE BREAK--- 3 TSS Assessment Regulated TSS Load City of Middleton Baseline Annual Total Suspended Solids Loads Description Area Annual TSS Load Study Area 14,714 ac 1084.5 tons/yr City Limits 5,189 ac 678.9 tons/yr Regulated Areas within City 3,670 ac 611.7 tons/yr TSS Assessment Current System Performance City of Middleton Current Total Suspended Solids Reduction Performance No Controls Annual Regulated Load 611.7 tons/yr TSS Removed by Street Sweeping 15.3 tons/yr Additional TSS Removed by Structural BMPs 202.0 tons/yr Total TSS Removed 217.3 tons/yr TSS Reduction Rate 35.5% ---PAGE BREAK--- 4 TSS Assessment Street Sweeping Alternatives City of Middleton Alternative Street Sweeping Programs TSS Reduction Performance Annual TSS Reduction Description Current Sweeping Schedule All Areas Swept Once per Week All Areas Swept Twice per Week Mechanical, No Parking Controls 2.5%1 5.3% 6.7% Mechanical, With Parking Controls 3.7% 7.5% N/A2 Vacuum, No Parking Controls 5.2% 10.9% 15.1% Vacuum, With Parking Controls 7.1% 14.2% N/A2 1. Reflects the City’s current street sweeping program 2. Twice-per-week sweeping with parking controls was not evaluated because it is felt to be infeasible to ban parking twice per week for street sweeping activities. TSS Assessment Recommended Alternatives 79-54-46 City of Middleton Proposed BMPs for compliance with NR151 TSS Reduction Requirements Alternative Description Total Annual TSS Reduction Estimated Capital Cost 1 • Increase Mechanical Sweeping Program To Once Per Week Schedule – No Parking Controls • Construct Structural BMPs 200.01, 300.01, 1200.01 40.1% $330,000 2 • Implement High Efficiency Street Sweeping, Once-per-Week with Parking Controls 40.3% $400,000 3 • Implement High-Efficiency Street Sweeping At Current Frequency, No Parking Controls • Construct Structural BMPs 200.01, 300.01, 1200.01, 1100.01 40.2% $615,000 4 • Maintain Current Sweeping Program • Construct Structural BMP 100.01 43.0% $880,000