Also, hazardous materials can be introduced to the environment through the agricultural, industrial, municipal, and transportation arenas. In non-point source pollution, fertilizer, pesticides, and manure contaminate water through runoff or by seeping into the ground and into the water table. Raw sewage and pesticides commonly enter water supplies due to municipal uses. In the industrial field, the effects of mining are a leading cause of fish kills. Chemicals also enter the environment via tanker trucks, rail transport, barges, and airliners through a single, detectable source known as point-source pollution.
Oil pollution occurs widely in both the nation's inland and coastal waters.
The source of oil and petroleum in streams, rivers, and lakes is generally not from one giant oil spill but from myriad sources that slowly trickle into waterways. For example, used oil that has been carelessly discarded accumulates in alarming amounts across the nation. To learn more about the magnitude of this contamination and how people can prevent it, click here . On the other hand, our oceans and coastlines are more impacted by serious oil spills which have increasingly occurred over the past few decades. To view a chart detailing the comparative sizes of some of these spills, click here .