Centralized Wastewater Collection and Treatment in Subdivisions, Mobile Home Parks and Campgrounds

Water Protection Program fact sheet
06/2019
Division of Environmental Quality Director: Ed Galbraith
PUB597

This fact sheet is for developers of subdivisions, mobile home parks, RV parks, and campgrounds. Centralized wastewater collection and treatment is required for the following situations or if required by county or municipal codes:

Lot Minimum Square footage*

Lot Minimum Acreage*

Subdivision

<40,000

<0.92

Mobile Home Park

<40,000

<0.92

RV Park

<40,000

<0.92

Campground

<40,000

<0.92

*Centralized treatment may be required for larger lots sizes based on the results of the Geohydrologic Evaluation of Residential Housing Development.

Background
The Disposal of Wastewater in Residential Housing Developments regulation10 CSR 20-6.030 is intended to assist in determining the method of wastewater treatment in new residential housing developments (subdivisions), an expansion of an existing subdivision and subdivisions that were required to receive approval under previous rule but had not.

Centralized systems using subsurface systems and designed for less than 3,000 gallons per day (GPD) are regulated by the Department of Health and Senior Services. For more information on less than 3,000 GPD systems, their jurisdictions, and onsite systems, see the following publications: If planning to use individual onsite wastewater treatment systems, follow the criteria in 10 CSR 20-6.030.

Continuing Authority
All centralized collection and treatment systems must have a continuing authority and must be designated on the applications. Continuing authority is the person who owns, operates, or provides area-wide management authority for a water contaminant source, point source, wastewater treatment facility, or sewer collection system. This person shall be designated as the continuing authority and shall sign the application.By doing so, the person designated as the continuing authority acknowledges responsibility for compliance with all permit conditions. 

“Person” is defined in section 644.016(15), RSMo, and includes a municipality, a sewer district, a water district, a private utility corporation regulated by the Missouri Public Service Commission, a non-profit sewer corporation, a neighborhood association, an individual, or a private corporation. The regulation, Construction and Operating Permits, 10 CSR 20-6.010 (2), lists the requirements for continuing authorities.

Geohydrologic Evaluation
A goehudrologic evaluation of the site is available from the Department’s Missouri Geological Survey. The evaluation must be completed prior to submitting the facility plan, because the liquid waste treatment facility/site evaluation results can affect treatment system design. Geohydrologic evaluations are required for all proposed new construction, new or major modification of earthen basins, new outfall locations, wastewater irrigation fields, and subsurface dispersal sites (10 CSR 20-6.010(4)(A)5.D). For questions regarding the geohydrologic evaluation, GeoEdge, or the forms, please contact the Environmental Geology Unit at 573-368-2100.

Antidegradation Review
If the proposed centralized wastewater treatment facility plans to discharge, an antidegradation review is required per 10 CSR 20-7.031(3). An antidegradation review is an evaluation of discharging alternatives from those that meet the minimum water quality standards to treatment technologies that perform better than the minimum. The Department has developed a general antidegradation review for facilities less than 50,000 GPD to help them meet the antidegradation requirements.

For more information on Antidegradation, see the Antidegradation Implementation Procedure or the Antidegradation webpage, (https://dnr.mo.gov/env/wpp/permits/antideg-implementation.htm).

Facility Plan
Facility plans must be submitted and approved prior to submittal of the construction permit application per 10 CSR 20-6.010(4)(A). See Facility Plan Guidance-PUB2416 for more information on permit requirements.

The facility plan must include the following information:

Construction Permits
Construction permits are required for all proposed domestic wastewater treatment facilities. The construction permit application must be submitted prior to the sale of lots. Submit the Construction Permit Application, Form MO 780-2189, with the appropriate fee. With the signed application, submit one hard copy and an electronic copy of the following information, per 10 CSR 20-6.010(5)(G), 10 CSR 20-8.110(8-10) and the other chapters of 10 CSR 20-8:

Submit the construction permit application to the Department’s Water Protection Program, Engineering Section. Construction can begin on the wastewater treatment system, including the collection system and the treatment plant, when a valid construction permit is received. 

The minimum design standards in 10 CSR 20-8 do not provide all the requirements to construct a complete and useable wastewater treatment facility. It is recommended that the engineer hired by the developer utilize published technical design guides to ensure effluent limitations can be met. If the Department has questions on the design, additional information or engineering justification may be requested to determine the facility’s ability to meet effluent limits per 10 CSR 20-6.010(5)(K).

For more information or for questions on facility plans or construction permits, please contact the Water Protection Program, Engineering Section at 573-751-1300 or at DNR.WPPEngineerSection@dnr.mo.gov.

Operating Permits
All centralized wastewater treatment systems require a Department-issued operating permit. The operating permit will provide the requirements the facility must meet, including effluent limits, sampling and reporting frequencies, and other conditions. For projects less than 50,000 GPD, many facilities are covered by the Department’s general permit, MOGD, for discharging systems and MOG823, for systems utilizing surface irrigation or subsurface dispersal.

For a new facility, submit the operating permit application, Form B- Application for Operating Permit for Domestic Wastewater, Form—MO 780-1512, and fee with the facility plan or the construction permit application.

For more information on Operating Permits, contact the Water Protection Program, Operating Permit Section at 573-751-1300.