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. Potomac River Upper Tidal (basin code 02-14-02-01), located in Prince Georges County and northern Charles County, was identified on the States list of WQLSs as impaired by nutrients (1996 listing), suspended sediments (1996 listing), copper (Cu, 1996 listing), polychlorinated biphenyls (PCBs, 2002 listing), and impacts to biological communities (2002 and 2004 listing). All impairments were listed for the tidal waters except for impacts to biological communities, which are listed for the non-tidal region. Code of Maryland Regulations (COMAR) 26.08.02.03- 1-B(3)(m)(i) defines the tidal Potomac River upstream of Upper Cedar Point, MD, which includes the Potomac River Upper Tidal, as a fresh waterbody. This report provides an analysis of recent monitoring data, including hardness data, which shows that the aquatic life criterion for Cu are being met in the Potomac River Upper Tidal.