Antidegradation

Fees: For a new wastewater treatment plant, if the design flow is less than 100,000 gallons per day the fee is $500; for a new wastewater treatment plant, if the design flow is equal to or more than 100,000 gallons per day the fee is $1000; for a review in which the existing wastewater treatment train is being retained as part of an upgrade or for a water quality review analysis the fee is $250.

General Antidegradation Review: The General Antidegradation Review has been revised. This voluntary review path is now available to domestic wastewater systems with design flows of up to 50,000 gallons per day and it now incorporates less-degrading effluent limits for Total Phosphorus when the proposed discharge to a Tier 2 water is located in the watershed of a lake greater than 10 acres.. Please note the following elements regarding this voluntary path:

  • The department conducted a general analysis of wastewater treatment alternatives for small systems in accordance with the Antidegradation Implementation Procedure, and concluded that there are several available technologies that are capable of producing a high quality effluent. Applicants that wish to use this general analysis only need to complete three documents/forms:
    • 1. Antidegradation Review Summary/Request.
    • 2. Antidegradation Review Submittal Voluntary Teir 2 -Significant Degradation for Domestic Wastewater Facilities with Design Flows Less than 50,000 gallons per day.
    • 3. Antidegradation: Regionalization and No-Discharge Evaluation. This optional approach would allow applicants to forgo the preparation of a site-specific alternatives analysis and eliminate the need to submit the "Path C” form.
  • Section 10 Antidegradation Review Sumittal Voluntary Tier 2 - Significant Degradation for Domestic Wastewate Facilities with Design Flows Less than 50,000 gallons per day provides a table of effluent limits that applicants will agree to accept using this approach.
  • This approach would only be available to new or expanding domestic wastewater treatment systems that will discharge to Tier 2 waters (those waters that are not impaired or are classified as Outstanding State or National Resource Waters).
  • The “Antidegradation: Regionalization and No-Discharge Evaluation form is used to demonstrate that regionalization is not feasible nor is land application or subsurface wastewater disposal.
  • The fee for this review will be $500.

Missouri Antidegradation Implementation Procedure - Approved July 13, 2016

Review Request Forms

Resource Documents

DO Modeling and BOD Effluent Limit Development Administrative Guidance for the Purpose of Conducting Water Quality Assistance Reviews
Presentation from Antidegradation Implementation Workshops (2.7 MB) June 2008 
Water Quality Monitoring in Support of Missouri's Antidegradation Rule