Abstract |
Section 303(d) of the federal Clean Water Act (CWA) and the U.S. Environmental Protection Agency's (EPA) implementing regulations direct each state to identify and list waters, known as water quality limited segments (WQLSs), in which current required controls of a specified substance are inadequate to achieve water quality standards. This list of impaired waters is commonly referred to as the 303(d) List. For each WQLS, the State is to either establish a Total Maximum Daily Load (TMDL) for the specified substance that the waterbody can receive without violating water quality standards, or demonstrate that water quality standards are being met. Upper North Branch Potomac River (basin code 02141005), located in Garrett County, Maryland, was identified on the States list of WQLSs as impaired by metals (1996 listing), sediments (1996 listing), nutrients (1996 listing), low pH (1996 listing) and impacts to biological communities (2002/2004 listing). The listing for metals is based on a water quality assessment found in the 1996 305(b) report developed by the Maryland Department of Natural Resources (DNR). This report provides an analysis of recent monitoring data. A Water Quality Analysis (WQA) of metals for the Upper North Branch Potomac River was conducted by MDE using recent water column chemistry data and sediment toxicity data to determine if an impairment currently exists. |