Source water refers to sources of water (such as rivers, streams, lakes, reservoirs, springs, and groundwater) that provide water to public drinking water supplies and private wells.

Protecting source water can reduce risks by preventing exposures to contaminated water. Drinking water utilities that meet the definition of a public water system are responsible for meeting the requirements of EPA and state drinking water programs under the Safe Drinking Water Act (SDWA). Protecting source water from contamination helps reduce treatment costs and may avoid or defer the need for complex treatment.

There are many additional benefits associated with source water protection, such as protecting water quality for wildlife and recreational use, and protecting the availability and quantity of water supplies.