Thursday, July 1, 2010

Nitrogen and Phosphorus Allocations For Chesapeake Bay TMDL

EPA has announced draft allocations for nitrogen and phosphorus as part of its plan for meeting water quality standards in the Chesapeake Bay and its tidal tributaries, and restoring local rivers and streams throughout the 64,000-square-mile watershed.

EPA proposed watershed-wide limits of 187.4 million pounds of nitrogen and 12.5 million pounds of phosphorus annually, and divided those allocations among the six watershed states and the District of Columbia, as well as the major river. These loadings were determined using the best peer-reviewed science and through collaboration with the states and the District of Columbia. EPA will assign draft allocations for sediment August 15.

In addition, EPA is committing to reducing air deposition of nitrogen to the tidal waters of the Chesapeake Bay to 15.7 million pounds per year. The reductions will be achieved through implementation of federal air regulations over the coming years.

The jurisdictions are expected to use the allocations as the basis for completing Watershed Implementation Plans, detailing how they will further divide these allocations among pollution sources, and achieve the required reductions. The first drafts of those plans are due to EPA by September 1. The jurisdictions are expected to have all practices in place to meet the established limits by 2025, with 60 percent of the effort completed by 2017.

EPA plans to issue a draft Total Maximum Daily Load (TMDL) for a 45-day public comment period on September 24. The final Phase 1 Watershed Implementation Plans are due November 29, and EPA will establish the Bay TMDL by December 31.

In 2017, the jurisdictions are expected to submit updated implementation plans to ensure that all the control measures needed to meet Bay water quality standards will be in place by 2025.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address water quality standards, wastewater permitting and assessing potential impacts of chemicals in the aquatic environment.

Caltha LLP Aquatic Toxicology / WQ Standards Services Website