The Environmental Protection Agency is obliged under the Clean Water Act to monitor America’s waterways and shield them from the toxic runoff from factory farms. But the growth of that industry, and its courtroom tenacity, has far outstripped the E.P.A.’s efforts to restrict runoff from manure lagoons and feedlots.

Last year, the agency meekly withdrew two proposed rules. One would have gathered basic information from all factory farms. The other proposed rule would have expanded the number of such farms required to have a national pollution discharge permit. Fewer than 60 percent do now.

Then, last week, in yet another retreat, the agency announced that promised new regulations governing feedlot discharges nationally would not be forthcoming.

According to the E.P.A.’s own studies, agricultural runoff is the leading cause of impaired water quality. The amount of manure produced by factory farms is staggering. The agency estimates that those operations create between 500 million and 1 billion tons of manure, three times as much waste as humans produce in the United States. The task of keeping those hundreds of millions of tons of animal waste out of rivers, lakes and estuaries is enormous, clearly requiring a strong set of revised regulations for the handling of factory-farm waste, including provisions for tracking waste when it’s been moved offsite.