Which of the following is a non-point source of water pollution?
Fertiliser runoff is a non-point source because nutrients leave many dispersed fields through rainfall, overland flow, erosion, and subsurface drainage rather than through one readily identified discharge pipe. Its loading varies with land use, weather, soil, and farm management. A sewage outlet or industrial effluent pipe is a point source whose location can be mapped and monitored directly. Community-level consequences can emerge when physiological injury changes survival, reproduction, species interactions, or the flow of energy through food webs. Aquatic effects depend on chemical form, pe
Ref: Campbell Biology, Urry et al., 12th Ed., Unit 8 Ecology