Final TMDLs Approved by EPA: Anacostia River

The Northeast Branch (NEB) and Northwest Branch (NWB) are tributaries of the Anacostia River, which in turn flows into the Potomac River, a tributary of the Chesapeake Bay. Approximately 70% of the Anacostia River watershed is drained by the NEB and NWB. The Anacostia River watershed is located in two physiographic provinces, the Piedmont Plateau and the Atlantic Coastal Plain, and drains about 176 square miles of land from Washington, DC (30.2 miles, 17.2%), Montgomery County, MD (60.8 miles, 34.4%), and Prince George’s County, MD (85.2 miles, 48.4%). The NEB and NWB watersheds combined are approximately 127 square miles and are home to approximately 519,000 residents.

The main channel of the Anacostia River is 8.4 miles (13.5 kilometers) in length, extending from the confluence of the NWB and the NEB, in Bladensburg, MD, to its confluence with the Potomac River. The main channel of the Anacostia River is an estuary with a variation in water level of approximately three feet over a tidal cycle. Tidal influence extends approximately to the locations of the U.S. Geological Survey (USGS) gaging station 01649500 on the NEB and the U.S. Route 1 (Rhode Island Avenue) bridge on the NWB.

The Maryland Department of the Environment (MDE), in the document available below, established TMDLs for polychlorinated biphenyls (PCBs) in the Northeast and Northwest Branches of the Anacostia River (basin code 02140205). MDE has identified various portions of the Anacostia River watershed on the State’s 2008 Integrated Report as impaired by the following (listing years in parentheses): nutrients (1996), sediments (1996), fecal bacteria (2002), trash/debris (2006), impacts to biological communities (2002), PCBs (2002), and heptachlor epoxide (2002). The 2002 PCB listing for the Anacostia River watershed refers solely to the Northeast Branch and Northwest Branch, where the water column samples were collected. Similarly, the 2002 heptachlor epoxide listing refers solely to the Northwest Branch. Maryland water quality standards state that all surface waters of the State shall be protected for water contact recreation, fishing, and protection of aquatic life and wildlife. All waters of the Anacostia River have been designated as Use I – Water Contact Recreation, and Protection of Aquatic Life. Additionally, Paint Branch and its tributaries upstream of the Capital Beltway have been designated as Use III – Cold Water, and the Northwest Branch and its tributaries upstream of Route 410 as Use IV – Recreational Trout Waters. 

Total Maximum Daily Loads of Polychlorinated Biphenyls in the Northeast and Northwest Branches of the Nontidal Anacostia River, Montgomery and Prince George's County, Maryland

(Approved on September 30, 2011)

EPA's Decision Letter EPA Decision Letter
(includes MDE's requested revisions)
MDE's Edits to EPA's Decision Letter MDE's Decision Letter Edits (22 KB)

Main Report

NEB_NWB_PCB_TMDL_20110930_Final.pdf (1,059 KB)
Comment Response Document NEB_NWB_PCB_TMDL_CRD_093011_Final.pdf (33 KB)

Contact Information

Please direct questions or comments concerning this project to Maryland's TMDL Program at (410) 537-3818.