Study Shows Divergent Views of Bay Nutrients at USDA, EPA

December 10, 2010 Bookmark and Share

A new report prepared for the Agricultural Nutrient Policy Council and released this week shows significant differences in Chesapeake Bay pollutant load estimates done by USDA and the Environmental Protection Agency (EPA), calling into question the data EPA is using in preparing new regulations for the region.

The report was prepared by water consulting firm LimnoTech, which concluded the differences are serious enough to request EPA stop its regulatory process and shift focus to work with USDA to reconcile the two’s studies.

The report indicates the two agencies diverge on issues of land use and total acreage in the Bay watershed; how water moves within the Bay; assumptions about conservation practices; how the models are structured; and what results those models produce.

Draft regulations imposing Total Maximum Daily Load requirements, known as TMDLs, and state plans to tackle pollution issues are all based on EPA data and the EPA model.

However, the LimnoTech report says, the differences between the EPA and USDA models call into question the legitimacy of the EPA information and must be dealt with before EPA issues final TMDL requirements, which is scheduled to be done by the end of the year.

The consequences of incorrect information could be severe for governments and businesses, including family farms, in the Bay watershed once the TMDL requirements are finalized.

The TMDL proposal is also concerning to many outside of the Chesapeake Bay watershed because, if finalized, it is likely to become the model for nutrient management in watersheds around the country.

In October, NAWG associated itself with comments to EPA requesting the draft TMDL be withdrawn to allow revisions to EPA’s models and in favor of working with Chesapeake watershed jurisdictions to reconcile the proposal with existing nutrient management plans in Bay states.

NAWG is a member of the Agricultural Nutrient Policy Council and will continue to work on this issue in collaboration with the coalition and other agricultural organizations, including NAWG’s affiliated state associations in Maryland and Virginia.