For water pollution there are two different sources, point source and non-point source.

Point source pollution comes from a specific source. Power plants, factories, sewage treatment plants and oil wells are all point sources. Point sources are easier to regulate and monitor than the non-point sources.

Non-point source pollution counts for the majority of our water pollution problem. This would include urban and agricultural run-off.

Urban run-off is the way that most of the oil, toxic chemicals, and heavy metals enter the water.

Agricultural run-off is mainly pesticides and fertilizers.

Fertilizers can cause significant damage in the water because they contain phosphorus. When phosphorus gets into the water it causes eutrophication. That's when Algae blooms out of control and deplete the water of oxygen. Fish and other animals suffocate.

Liter is also part of the water pollution problem. Things like cigarette butts, aluminum cans, and plastic six-pack covers stick around for many years and injure, even kill hundreds of thousands of mammals, fish, and birds.

Water pollution has become a very serious concern for many people. Estimates are that 1.5 BILLION people are without safe drinking water and at least 5 MILLION die each year from water-born diseases.