GEOLOGY

Detailed explanation-1: -Runoff is a major cause of nonpoint-source pollution.

Detailed explanation-2: -Nitrogen is the key, high-volume pollutant in state rivers and streams and has been increasing over time.

Detailed explanation-3: -Around the world, agriculture is the leading cause of water degradation. In the United States, agricultural pollution is the top source of contamination in rivers and streams, the second-biggest source in wetlands, and the third main source in lakes.

Detailed explanation-4: -Urban runoff or ‘storm drain pollution’ is one of the leading causes of water pollution in this country. Urban areas may contain up to 90 percent hard, impervious surfaces such as rooftops, sidewalks, streets, construction sites and parking lots and pavement where water collects and quickly runs off.

Detailed explanation-5: -Point source pollution is pollution that comes from one single point, or site and directly into a water body. For example, water from a pipe flowing into a river.