U.S. flag

An official website of the United States government

Dot gov

Official websites use .gov

A .gov website belongs to an official government organization in the United States.

Https

Secure .gov websites use HTTPS

A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites..

Pollutants

Substances that include, but are not limited to, any solid, liquid, gaseous or thermal irritant or contaminant, including smoke, vapor, soot, fumes, acids, alkalis, chemicals and waste. "Waste" includes, but is not limited to, materials to be recycled, reconditioned or reclaimed.

Last updated March 5, 2020