Different state and local agencies are responsible for regulating wastewater treatment systems, ranging from a simple septic system serving a single-family residence to a centralized wastewater collection and treatment system serving an entire community.

Who Regulates?

Department of Health and Senior Services

The on-site wastewater treatment program or local on-site wastewater authority, typically the county health department, has jurisdictional authority for domestic wastewater treatment systems only that include:

  1. An individual on-site wastewater treatment (septic) system (OWTS) with subsurface soil dispersal system that serves a single family residence
  2. An individual lagoon (earthen basin) that serves no more than a single family residence
  3. Cluster or centralized systems with subsurface soil dispersal under the same common promotional plan within the same operating location when the maximum daily flows of domestic wastewater is less than or equal to 3,000 gallons per day (gpd) including offices, motels/hotels, RV parks, theaters and restaurants

The Missouri Department of Health and Senior Services set minimum state standards for OWTS. These standards cover new systems and major changes to existing systems. Some examples of major changes are replacing a sewage tank, and replacing or expanding an absorption field. These standards became effective January 1996.

For more information, contact Missouri Department of Health and Senior Services, Bureau of Environmental Health Services, P.O. Box 570, Jefferson City, MO  65102, 800-628-9891 or 573-751-6095.

Department of Natural Resources

Responsibilities include:

  1. Approving the method of domestic wastewater treatment in new residential housing developments (such as subdivisions, recreational developments and multiple family housing units) and expanding an existing development when they meet specific criteria
  2. All wastewater treatment systems with direct point discharge or surface land application systems regardless of maximum daily flows or type of waste treated
  3. All lagoons (earthen basins) other than an individual lagoon regardless of maximum daily flows or type of waste treated
  4. Any facility that has a maximum daily flow of domestic wastewater greater than 3,000 gpd
  5. All industrial process waste not defined as domestic wastewater, such as process waste from a brewery, a winery, a dog kennel, stormwater, etc.

For more information, contact Missouri Department of Natural Resources, Water Protection Program, P.O. Box 176, Jefferson City, MO 65102-0176, 800-361-4827 or 573-751-1300.

Additional Information



The reference materials listed below are intended to provide a sample of what is available concerning suitability, designing, installing and operating and maintaining OWTS, cluster and centralized wastewater treatment systems.

Department of Health and Senior Services (DHSS)

​​​Department of Natural Resources