Stormwater runoff from developed land transports pollutants to receiving waters. Runoff picks up contaminants such as oil that leaks from vehicles and the pesticides or fertilizers used in lawns and gardens. Construction site erosion, and the resulting sedimentation, is another source of pollution.
Source controls are the most effective means of preventing stormwater pollution and protecting water quality. Source control best management practices (BMPs) keep pollutants from entering stormwater in the first place. Source control BMPs are aimed at preventing or minimizing pollutants through performing routine work in a way that eliminates, or greatly reduces, the likelihood of contaminants getting into stormwater.