In the U.S., the Environmental Protection Agency (EPA) regulates water pollution under the auspices of the Clean Water Act, the Safe Drinking Water Act and other environmental laws. With the help of state and local authorities, the EPA establishes water quality standards, promotes guidelines for best management practices, and issues permits to point source polluters and treatment facilities. The Agency also offers compliance assistance to the regulated community and seeks punitive legal action against violators of water pollution laws and regulations.

Source: EPA