Point sources usually involve a direct discharge of pollution from a specific source. Many of these point sources were established before much was known about the damage they would inflict on the environment. Sewage treatment plants introduce organic material and pathogens into the groundwater supply. Livestock facilities take advantage of the few laws regulating the runoff that is released into the watershed of nearby streams and rivers. The shift in raising livestock from open field grazing methods to a large scale industry is causing concentrations of manure in isolated areas.
Livestock produces three to four times the amount of waste that of the average person.
To handle large amounts of manure, lagoons are biult on the premises with the runoff seeping into these areas. The threat that lagoons will spill or break open is another issue.