An official website of the United States government.

We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Septic Systems

Learn About Septic Systems

Septic systems are used to treat and dispose of small volumes of wastewater onsite, usually from houses and businesses located in suburban and rural locations not served by a centralized public sewer system. Septic systems treat wastewater from household plumbing fixtures (toilet, shower, laundry, etc.) through both natural and technological processes.

Septic systems are also called:

  • onsite wastewater treatment systems,
  • decentralized wastewater treatment systems,
  • cluster systems,
  • package plants,
  • on-lot systems,
  • individual sewage disposal systems, and
  • private sewage systems.

For simplicity, these terms are used interchangeably throughout this Septic Systems web site.

In this area: