Water pollution is the contamination of waterbodies such as streams, rivers, lakes, and bays, often caused by human actions. Point source pollution is contamination that can be traced to a specific source such as a wastewater pipe or an industry, and laws regulate this type of contamination. Nonpoint source pollution happens when contamination on the landscape is carried to waterbodies by rain or irrigation water, and it is hard to control with laws. Citizens and landowners must make good decisions to help prevent it.