This document, upon approval by the U.S. Environmental Protection Agency (EPA), establishes a Total Maximum Daily Load (TMDL) for sediment in the Upper North Branch Potomac River Watershed (basin number 02141005). Section 303(d) of the federal Clean Water Act (CWA) and the EPA's 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, the State is required to either establish a TMDL of the specified substance that the waterbody can receive without violating water quality standards, or demonstrate that water quality standards are being met. (CWA, 2006) The Maryland Department of the Environment (MDE) has identified the waters of the Upper North Branch Potomac River (basin number 02141005) on the States 303(d) List submitted to the U.S. Environmental Protection Agency by MDE as impaired by nutrients (1996), sediments (1996), pH (1996), metals - unspecified (1996), methylmercury (2002), and portions of the basin for impacts to biological communities (2002 and 2004) (MDE, 2006a). The designated use of the Upper North Branch Potomac River is Use I-P (Water Contact Recreation, Protection of Aquatic Life, and Public Water Supply) (COMAR, 2006a).