Animal agriculture is a major source of water pollution in the United States, as manure runoff carries excess nutrients into rivers and lakes. Because of their non-point source nature, most farms are not regulated under the federal Clean Water Act. This leaves pollution control up to the states, resulting in a patchwork of different approaches that are difficult to evaluate.
Click here for original story, Local manure regulations can help reduce water pollution from dairy farms
Source: Phys.org