Onsite Wastewater Treatment Systems: Septic Systems Definitions

Septic (OWTS) Definitions

Onsite wastewater treatment system (OWTS) is a broad term referring to any system for the collection, storage, treatment, neutralization, or stabilization of sewage that occurs on the property.

A septic system is a type of OWTS, consisting of a septic tank that collects all the sewage. The sewage separates into a solid (sludge) that settles to the bottom, and a liquid effluent that then flows into a leach field for final treatment by the soil.

OWTS are used to treat and dispose of relatively small volumes of wastewater, usually from houses and businesses that are not a part of or connected to a sewage treatment works.

Regulatory definition: OWTS – an absorption system of any size or flow or a system or facility for collecting, storing, treating, neutralizing, stabilizing, or disposing of sewage which is not a part of or connected to a sewage treatment works.

Please Note: This information is intended to provide a better understanding of the functions of onsite wastewater treatment and the need for proper design, installation, and maintenance. Always consult a licensed professional or public health official with questions regarding engineering, installation, and servicing of onsite wastewater systems.

Contact Us

SepticSmart Program

Main: 303-441-1564
Submit a question


3450 Broadway
Map & Directions
Hours: 8 a.m. - 4:30 p.m. M-F