States manage stormwater runoff in cities and towns through the Municipal Separate Storm Sewer System (MS4) Program. In Tennessee, the Tennessee Department of Environment & Conservation (TDEC) released a new MS4 permit for smaller cities on September 30, 2016. TCWN appealed the permit on October 28, 2016, because TCWN alleges that the permit is not strong enough to protect water quality and lacks some provisions that allow the public to participate in the storm water management process.
Stormwater runoff is a national concern streams and rivers. Runoff of stormwater from human-modified landscapes can change natural hydrologic patterns and elevate pollutant concentrations. Runoff may contain (or mobilize) contaminants including sediment, suspended solids, nutrients, heavy metals, pathogens, and oxygen-demanding substances.
Tennessee streams and rivers face impairment due to stormwater runoff. According to the 2014 TDEC 305(b) report, approximately half of assessed Tennessee streams are impaired. Of those, stormwater runoff causes over 2,400 miles of streams to not meet their designated uses.
Litigation is ongoing for the MS4 Phase II Permit appeal. A hearing is scheduled for January 16, 2018.