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. 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) of the specified substance that the waterbody can receive without violating water quality standards, or demonstrate that water quality standards are being met. Bynum Run (basin code 02130704), located in Harford County, Maryland, was identified on the States list of WQLSs as impaired by sediments (1996 listing), nutrients (1996 listing), and impacts to biological communities (2002 listing). This document, upon EPA approval, addresses the nutrient impairment in Bynum Run; the sediment and biological impairments will be addressed at a future date.