Nonpoint source pollution:
Pollutants that are not discharged or emitted from a specific "point" source, such as a pipe or smokestack. Nonpoint water pollutants are often carried from dispersed, diverse sources into water channels by rain-induced runoff. Runoff from streets, open pit and strip mines, and agricultural fields are prominent examples (see agricultural pollution). Nonpoint source air pollutants (often called fugitive emissions) include small dispersed sources, e.g., fireplace smoke, and uncontained emissions, like dust blown from fields and unpaved roads.