On-site Septic Systems and Subdivisions

In Missouri, different state and local agencies are responsible for regulating wastewater treatment systems. Additional information is also available in the following publications:

• Who Regulates Wastewater In Missouri? - PUB1296
• Jurisdiction Flow Chart

Missouri Department of Natural Resources

The Missouri Department of Natural Resources’ is responsible for the following:

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 gallons per day (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 the department's Water Protection Program, P.O. Box 176, Jefferson City, MO 65102-0176, or by telephone at 573-751-1300.

Missouri Department of Health and Senior Services or Local Agency

The Missouri Department of Health and Senior Services (DHSS) or a local agency, typically the county health department, is responsible for domestic wastewater treatment systems that include the following:

1. An individual on-site wastewater treatment (septic) system 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 gpd. This includes offices, motels, hotels, recreational vehicle (RV) parks, theaters and restaurants

For more information, visit DHSS' Onsite Wastewater Treatment webpage or call their Onsite Wastewater Treatment Program at 573-751-6095.

The reference materials listed below are intended to provide a sample of what is available concerning suitability, designing and installing on-site wastewater treatment (septic), cluster and centralized wastewater treatment systems.

Publications

• ​3,000 Gallon Per Day or Less No-discharge Permit Exemption for Domestic Wastewater Design Guidance - PUB1319
• Centralized Wastewater Collection and Treatment in Subdivisions, Mobile Home Parks and Campgrounds - PUB597
• Disposal of Wastewater in Residential Housing Developments 10 CSR 20-6.030 - PUB2225
• Jurisdictional Change of a Domestic Wastewater Facility - PUB2691
• On-Site Wastewater Treatment (Septic) in a Subdivision - PUB2226
• Pump and Haul Operating Permit Exemption - PUB2658
• Wastewater Treatment Facility Permit Fees - PUB2564

Forms

• Request for Approval Under 10 CSR 20-6.030 Disposal of Wastewater in Residential Housing Developments MO 780-1760
• Request for Alternative Determination Under 10 CSR 20-6.030 For Wastewater Handling and Disposal In Residential Housing Developments MO 780-3083

Other Resources

• Decentralized Wastewater Treatment Glossary, Second Edition 2009 - Consortium of Institutes for Decentralized Wastewater Treatment
• Find an Onsite Wastewater Professional - DHSS - Find Installers, Inspectors and Soil Evaluators
• OWTS Construction Permit Application Process - DHSS - Required before installing or repairing most OWTS
• OWTS Frequently Asked Questions - DHSS
• Resources - DHSS - Site/ Soil Evaluation, OWTS Professional Registration, OWTS Installers, Licensed OWTS Inspectors
• Soil Survey Manual (USDA, Agriculture Handbook No. 18) - U.S. Department of Agriculture, Natural Resources Conservation Service
• Web Soil Survey - U.S. Department of Agriculture, Natural Resources Conservation Service 

When functioning properly, onsite systems prevent human contact with sewage, and prevent contamination of surface and groundwater. The reference materials listed below are intended to provide information about operating and maintaining on-site wastewater treatment (septic), cluster and centralized wastewater treatment systems.

• An Onsite Wastewater Treatment System Owner’s Manual - DHSS
• Missouri Smallflows Organization
• OWTS Construction Permit Application Process - DHSS - Required before installing or repairing most OWTS
• SepticSmart - U.S. Environmental Protection Agency - A nation-wide initiative to share information on the proper care and maintenance of septic systems and encourage public stewardship in caring for these wastewater treatment systems

No person or property owner may operate onsite systems in a manner as to cause a nuisance, health hazard or contaminate surface water or groundwater. To file a complaint:

• For complaints regarding an OWTS, use the Missouri Department of Health and Senior Services' Onsite Wastewater Complaints form. 
• For complaints regarding city sewers and wastewater treatment plants, contact your local Missouri Department of Natural Resources' regional office.