WASHINGTON—A final update of a report on the science surrounding Chesapeake Bay water quality confirms significant differences between the U.S. Environmental Protection Agency’s bay model and the model used by the U.S. Department of Agriculture.

The American Farm Bureau Federation asserts that those differences, left unaddressed, could lead to farmers in the bay’s six-state watershed paying a steep price for pollution mistakenly attributed to them.

AFBF and the Pennsylvania Farm Bureau filed a federal lawsuit against the EPA in January to block that agency’s total maximum daily load or "nutrient diet" regulatory plan for the bay watershed.

The analysis, conducted for the Agricultural Nutrient Policy Council, shows differences between the EPA and USDA models in the areas of land use, total acreage of the bay watershed, and data and assumptions about farm practices.

As a result, there is a wide discrepancy in the nutrients and sediments in the bay being attributed to agriculture. AFBF President Bob Stallman said that, given the USDA’s superior knowledge of agriculture and farming practices, the EPA’s disregard for USDA information is not acceptable.

"While we need EPA and USDA to work together to resolve these key differences, ultimately we believe that the types of regulations put in place for the bay by EPA are unlawful. This is a job for our state governments, not the federal government. But, since federal regulators are pursuing restrictive regulations on our farms, they should at least base their actions on credible facts."

A copy of the report is available at nutrientpolicy.org/ANPC_News.html.

A recent report released by the USDA’s Natural Resource Conservation Service indicated 96 percent of farmers in the Chesapeake Bay watershed have implemented erosion control practices on cropland acres in production. It also said sediment contributions from cultivated cropland to the bay's tributaries have been reduced by 64 percent, while phosphorus was reduced by 43 percent and nitrogen by 36 percent between 2003-2006.

In addition, NRCS said pollution has been reduced by another 15 percent to 20 percent over the past five years.