This document, upon approval by the U.S. Environmental Protection Agency (EPA), presents a Water Quality Analysis (WQA) of sediment in the Middle Patuxent River watershed (basin number 02131106) (2008 Integrated Report of Surface Water Quality in Maryland Assessment Unit ID: MD-02131106). Section 303(d) of the federal Clean Water Act (CWA) and the EPAs 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 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 Maryland Department of the Environment (MDE) has identified the waters of the Middle Patuxent River watershed on the States 2008 Integrated Report as impaired by metals - zinc (1996), sediments (1996), and nutrients nitrogen and phosphorus (1996) (MDE 2008). The designated use of the Middle Patuxent River mainstem and its tributaries is Use I-P (Water Contact Recreation, Protection of Aquatic Life, and Public Water Supply) (COMAR 2009a,b).