Chesapeake Bay Restoration

Monitoring data continues to show that the Chesapeake Bay has poor water quality, degraded habitats, and low populations of many species of fish and shellfish. This is due in large part to excess nitrogen, phosphorus, and sediment from agricultural operations, urban and suburban runoff, wastewater, airborne contaminants, and other sources.

The excess nutrients and sediment lead to murky water and algae blooms, which block sunlight from reaching underwater bay grasses and create low levels of oxygen for aquatic life such as fish, crabs, and oysters. State efforts to clean up the Bay have fallen short of their goals.

In December 2010, the U.S. Environmental Protection Agency (EPA) issued enforceable limits for pollution in the Bay and its tidal rivers through a regulatory plan required under the Clean Water Act called a Total Maximum Daily Load (TMDL). A TMDL establishes a “pollution diet” or maximum amount of a pollutant that can be found in a body of water that, if achieved, leads to restoration of that water.

The Bay TMDL is the largest and most complex ever developed, involving six states and the District of Columbia and the impacts of pollution sources throughout a 64,000-square-mile watershed.

Under the Bay-wide TMDL, EPA requires states to provide much more detail about how they will achieve pollution reductions from all sources through enforceable measures. States must specify reductions they intend to get from “point sources” like sewage treatment plants, urban stormwater systems, and large animal feeding operations and from “non-point sources” such as polluted rainfall runoff from agricultural lands and hard surfaces. The plans will be supported by a series of two-year milestones for achieving specific near-term pollution reduction actions and targets needed to keep pace with commitments. EPA will invoke strict consequences, including loss of funding, if states fail to develop adequate implementation plans or fail to make progress in achieving the necessary pollution reductions. The TMDL also requires states to set pollution caps for smaller geographic areas, such as counties, where much of the pollution reduction implementation takes place.

Resources
Additional information on the Chesapeake Bay TMDL, including the Executive Summary, fact sheets, and frequently asked questions is available at on the EPA Web site.