Every time we wash a car or use fertilizer on our lawns we are polluting the ocean. People often think that water pollution comes from big factories, but most of the pollution comes from everyday people doing everyday things. This kind of pollution is called "nonpoint-source pollution" because we cannot point out where it came from directly. All waste water, in time, enters a body of water (usually a stream). Every stream leads to a river, and every river leads to an ocean.