from the Clean Water Act,a source of pollution from "any discernable, confined and discrete conveyance, including but not limited to any pipe, ditch, channel, tunnel, conduit, well, discrete fissure, container, rolling stock, concentrated animal feeding operation, or vessel or other floating craft, from which pollutants are or may be discharged." Irrigation return flows and agricultural storm water discharges are specifically exempted from the definition. Point sources of pollution are amenable to regulation through specific effluent limitations which require monitoring and treatment of the waste stream. The wastes coming out of the end of a pipe at a factory are an example of point source.