Protecting Public Health and the Environment.

IPDES Pretreatment Program

DEQ’s pretreatment program regulates pollutants from industrial and commercial facilities that discharge directly into POTWs. The objectives for the pretreatment program are as follows:

  • Prevent the introduction of pollutants into a POTW that will interfere with the operation of the POTW, including interference with the use or disposal of sewage sludge.
  • Prevent the introduction of pollutants into a POTW that will pass through the treatment works or otherwise be incompatible with the works.
  • Improve the opportunities to recycle and reclaim municipal and nonmunicipal wastewater and sewage sludge.

DEQ relies on a POTW to regulate industrial dischargers to its sewer system to protect the health and safety of staff and the integrity of the treatment process. A POTW with a total design flow greater than 5 MGD receiving discharges from industrial users (IUs) that could interfere with or pass-through the POTW’s operations, or are otherwise subject to pretreatment standards, may be required to develop a pretreatment program. DEQ may also require a POTW with a design flow less than 5 MGD to develop a pretreatment program if the POTW receives significant wastewater contributions from industrial sources that warrant a pretreatment program to prevent interference or pass-through. DEQ is the approval authority responsible for the following:

  • Reviewing and approving a POTW’s pretreatment program application.
  • Designating the POTW as the control authority authorized to control discharges to its POTW.
  • Ensuring that the POTW complies with pretreatment conditions in its IPDES permit and with the appropriate provisions of 40 CFR 403.

In addition, DEQ ensures that a SIU discharging to a POTW without an approved pretreatment program complies with the National Pretreatment Standards (40 CFR 403.6). DEQ will act as the control authority for POTWs that need an approved program but do not have one. In some cases, DEQ will assist the POTW with developing the necessary program elements to ensure timely approval and implementation of a program that complies with the National Pretreatment Standards. In other cases, DEQ may permanently act as the control authority for a POTW's IUs and will work directly with the POTW to develop local limits, where necessary, and issue control mechanisms.

Response to Public Comments

Description of Modification Public Comment Start Date Public Comment End date Response to Comments Approval
City of Burley–Major Modification to Relax Chromium and Silver Local Limits September 17, 2019 October 17, 2019 Response to comments Approval