Chesapeake Bay Total Maximum Daily Load

Chesapeake Bay Total Maximum Daily Load
Name	Chesapeake Bay Total Maximum Daily Load
Date issued	December 29, 2010
Issuing authority	United States Environmental Protection Agency
Jurisdiction	Chesapeake Bay watershed
Status	Active

Chesapeake Bay Total Maximum Daily Load. The Chesapeake Bay Total Maximum Daily Load is a comprehensive pollution diet established by the United States Environmental Protection Agency to restore the health of the Chesapeake Bay. Mandated under the Clean Water Act, it sets legally enforceable limits on the amount of nitrogen, phosphorus, and sediment that can enter the bay from across its vast watershed. This landmark regulatory action coordinates efforts among multiple states, the District of Columbia, and numerous stakeholders to address decades of water pollution and eutrophication.

Background and Legal Framework

The need for the TMDL arose from the persistent degradation of the Chesapeake Bay, historically one of the most productive estuaries in North America. Despite voluntary agreements like the 1983 Chesapeake Bay Agreement, water quality continued to decline due to pollution from agricultural runoff, wastewater discharges, and urban stormwater. Legal action by the Chesapeake Bay Foundation and other parties led to a 2009 executive order by President Barack Obama and a subsequent settlement that compelled the EPA to establish the TMDL. The legal foundation is Section 303(d) of the Clean Water Act, which requires states to identify impaired waters and develop TMDLs, a process overseen by the EPA Region 3.

Development of the TMDL

The development process was a massive scientific and regulatory undertaking led by the EPA in partnership with the Chesapeake Bay Program. It involved extensive data collection and modeling using tools like the Chesapeake Bay Watershed Model. Key partners included the states of Virginia, Maryland, Pennsylvania, New York, Delaware, West Virginia, and the District of Columbia. The draft TMDL was released for public comment in 2010, receiving input from agricultural groups, environmental organizations, and municipalities. The final TMDL was issued on December 29, 2010, establishing a restoration timeline with incremental milestones leading to 2025.

Key Components and Allocations

The TMDL sets specific numeric limits for annual loads of nitrogen, phosphorus, and sediment. The overall cap requires a nearly 25% reduction in nitrogen and phosphorus and a 20% reduction in sediment compared to 2009 levels. These caps are subdivided into allocations for each major jurisdiction and further divided among key pollution source sectors: agriculture, wastewater, stormwater, and septic systems. For example, significant reductions were assigned to Pennsylvania for agricultural runoff and to Virginia for upgrades to wastewater treatment facilities like the Blue Plains Advanced Wastewater Treatment Plant.

Implementation and the Watershed Implementation Plans

Implementation is carried out through state-specific Watershed Implementation Plans developed by each jurisdiction. These WIPs detail the specific best management practices, such as cover crops and stream restoration, that will be used to meet the allocations. The EPA evaluates these plans and can impose consequences, such as increased oversight of discharge permits, for inadequate progress. Funding and technical assistance are provided through programs like the Chesapeake Bay Program and the National Fish and Wildlife Foundation. Implementation involves coordination with local counties and soil and water conservation districts.

Progress, Challenges, and Controversies

Progress has been mixed, with notable successes in reducing point source pollution from upgraded facilities in Maryland and Virginia. However, major challenges remain, particularly in controlling nonpoint source pollution from agriculture in Pennsylvania and stormwater in growing urban areas. The TMDL has faced legal challenges from groups like the American Farm Bureau Federation, which argued it overstepped EPA authority, but was upheld by the U.S. Court of Appeals for the Third Circuit and the Supreme Court of the United States. Ongoing debates concern the cost of implementation, the pace of progress, and the impacts of climate change and population growth.

Scientific and Economic Impact

Scientifically, the TMDL has driven advancements in environmental modeling and monitoring, including the work of the University of Maryland Center for Environmental Science. It has led to a more nuanced understanding of pollutant transport and the effectiveness of conservation practices. Economically, the plan has spurred significant investment in green infrastructure and environmental engineering, while also imposing costs on farmers and municipalities. Studies by institutions like the Chesapeake Bay Commission indicate that achieving the TMDL goals would generate substantial benefits for the commercial fishing industry, tourism, and property values around the Chesapeake Bay.

Category:Water pollution in the United States Category:Chesapeake Bay Category:United States Environmental Protection Agency Category:Clean Water Act