A federal appeals court has upheld the Environmental Protection Agency’s ability to limit pollution that enters waterways from nonpoint sources such as logged-over hillsides, roads, and farms. The agency sets what are known as “Total Maximum Daily Loads” — that is, the amount of all pollutants a given waterway can tolerate and still meet water quality standards.

The case decided by the Ninth Circuit Court of Appeals in San Francisco involved a challenge lodged by private landowners in the watershed of the Garcia River in northern California and supported by the American Farm Bureau Federation and two divisions of that organization. They argued that when the only sources of pollution in a watershed are of the nonpoint variety (as opposed to point sources, like refineries, pulp mills, or sewage-treatment plants), EPA has no right to establish a TMDL. The court firmly rejected that argument, which will set a precedent for western states and be a beacon for courts in other areas of the country, which have yet to consider this particular argument.

This case grew out of earlier litigation brought by Joe Brecher of Earthjustice on behalf of more than a dozen organizations to force EPA to set TMDLs for 17 northcoast rivers. The Garcia was the first for which a TMDL was set, and it was promptly challenged by the landowners and the Farm Bureau. Brecher intervened in the present case to bolster the government’s defense of its right to enact the standards.