Complex sentence: Nonpoint source (NPS) pollution is water pollution affecting a water body from diffuse sources, such as polluted runoff from agricultural areas draining into a river, or wind borne debris blowing out to sea.
Split into simpler sentences: Nonpoint source (NPS) pollution is water pollution affecting a water body from diffuse sources, rather than a point source which discharges to a water body at a single location. Examples are polluted runoff from agricultural areas draining into a river and wind borne debris blowing out to sea.