Water Quality Analysis of Eutrophication for the Evitts Creek Basin in Allegany County, Maryland.

摘要

Section 303(d) of the federal Clean Water Act (CWA) and the U.S. Environmental Protection Agencys (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. For each WQLS listed in the Integrated Report of Surface Water Quality in Maryland (Integrated Report) (MDE 2008a), the State is to either establish a Total Maximum Daily Load (TMDL) of the specified substance that the waterbody can receive without violating water quality standards, or demonstrate that water quality standards are being met (CFR 2009). The Evitts Creek watershed (basin code 02141002) (2008 Integrated Report Assessment Unit ID: MD-02141002) was identified in Marylands 2008 Integrated Report as impaired by nutrients (1996 listing, Lake Habeeb 1998 listing), sediment (1996 listing), pH (1996 listing, Rocky Gap Run 2006 listing), and impacts to biological communities (2006 listing) (MDE 2008a). A Water Quality Analysis (WQA) for low pH was completed in 2005 to address the 1996 listing. A TMDL for nutrients to address the 1998 Lake Habeeb listing was completed in 1999, and a TMDL for sediments was completed in 2006. The 1996 nutrients listing was refined in the 2008 Integrated Report by identifying phosphorus as the specific impairing substance. Consequently, for the purpose of this report the terms nutrients and phosphorus will be used interchangeably. The listings for impacts to biological communities and the 2006 Rocky Gap Run pH listing will be addressed separately at a future date.