Chesapeake Bay TMDL (Total Maximum Daily Load)

In 1998, major portions of Chesapeake Bay and its tidal tributaries within Virginia were identified as not meeting water quality standards and listed as impaired. Areas of the Bay and tidal rivers within Maryland, Delaware and the District of Columbia are also on the federally approved list of impaired waters. The main pollutants causing these impairments are nitrogen, phosphorus, and sediment. Significant efforts have been taken and resources expended by federal, state, and local governments and other interested parties throughout the entire 64,000 square mile Chesapeake Bay watershed. Despite these efforts the water quality goals under the Clean Water Act have yet to be met.

Because these Bay waters remained on the impaired waters list, EPA required that a Total Maximum Daily Load (TMDL) be developed. EPA issued the Bay TMDL on December 29, 2010. It was based, in part, on the Watershed Implementation plans developed by the Bay watershed states and the District of Columbia.

More information on this subject can be seen at the following agency websites:

The following documents are also available for review:


Program Contact

Mark Bittner
Director of Planning & Information Technology
(804) 861-1666 x237