All construction permits for new or expanded discharges are required to follow the Missouri Antidegradation Rule and Implementation Procedure. 

Missouri Antidegradation Implementation Procedure

On July 13, 2016, the Missouri Clean Water Commission approved the most recent revision to the Missouri Antidegradation Implementation Procedure (AIP), which EPA approved July 30, 2018. According to 40 CFR 131.12, this procedure is intended to satisfy a requirement for states to develop and adopt a statewide antidegradation policy and identify methods for implementing such policy.

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. It also 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:


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. For a new wastewater treatment plant, the fee is determined by design flow:

  • $500 - design flow is less than 100,000 gallons per day
  • $1000 - design flow is equal to or more than 100,000 gallons per day

Additional Information