We've made some changes to EPA.gov. If the information you are looking for is not here, you may be able to find it on the EPA Web Archive or the January 19, 2017 Web Snapshot.

Idaho NPDES Program Authorization


The Idaho Department of Environmental Quality (IDEQ) is seeking approval to administer the Idaho Pollutant Discharge Elimination System (IPDES) program regulating discharges of pollutants into waters of the United States under its jurisdiction.

If EPA approves the IPDES program, the IDEQ will administer this program in place of the National Pollutant Discharge Elimination System (NPDES) program currently administered by the EPA. If approved, NPDES program authority will transfer from EPA to IDEQ on or after July 1, 2018.

EPA will retain authority for NPDES permits for discharges to tribal waters.

EPA is Seeking Comments on Idaho's Application

60-day public comment period ends October 10

The EPA will consider comments on the IPDES program application before making a final decision. You may submit comments by any of the following methods through October 10, 2017:

  • Email: IdahoNPDEScomments@epa.gov
  • Mail/Hand Delivery/Courier: U.S. EPA, Attn: Idaho NPDES Comments, Office of Water and Watersheds, Mail Stop OWW-191, 1200 Sixth Avenue, Suite 900, Seattle, WA 98101-3140.

Electronic copies of documents are available under "Documents" below. Copies are also available for review and copying at the following locations:

EPA Region 10 Library
1200 Sixth Avenue, Suite 900 (M/S OMP-0102), Seattle, WA 98101
Hours: Monday-Friday, 9am-12pm and 1pm-4pm

EPA Idaho Operations Office
950 W Bannock, Suite 900, Boise, ID 83702

Public Hearings and Informational Meetings

EPA and the Idaho Dept. of Environmental Quality held a series of public meetings at the locations listed below. Presentations and handouts from the public meetings are available.

  • September 11, 2017 at Central Public Library in Idaho Falls.
  • September 12, 2017 at Twin Falls Public Library.
  • September 13, 2017 at Boise Public Library.
  • September 14, 2017 at Lewiston Community Center.
  • September 15, 2017 at Coeur d'Alene Public Library.

Related Information



Application Documents

We are accepting public comments on the following documents that were submitted to EPA on August 31, 2016, and updated on August 1, 2017, as part of Idaho's program submission.

The following links exit the site Exit
  1. Letter from Idaho governor to EPA requesting approval of State's application (PDF)(2 pp, 488 K, About PDF) - August 9, 2016
  2. IPDES Program Description (PDF)(443 pp, 26 MB) - Revised July 2017. Document describes how the state will issue IPDES permits, ensure compliance with permit conditions, conduct enforcement, as well as fund and manage the program including programmatic information and data.
  3. Statement from Idaho Attorney General's Office (PDF)(92 pp, 1 MB) - August 1, 2017. Letter and supporting information confirming that the state’s laws and regulations provide sufficient authority to the state to implement the discharge, pretreatment, and biosolids components of the NPDES program.
  4. Memorandum of Agreement (MOA) Between Idaho and EPA Region 10 (PDF)(83 pp, 1 MB) - Document establishes, in part, timeframes for a phased approach for the state to assume authority.
    • Note: On August 29, 2017, EPA provided a correction to Appendix F of the MOA (see "Additional Correspondence" below).
  5. Water Quality Planning in Idaho: Continuing Planning Process (PDF)(4 pp, 261 K)
  6. Applicable State statutes and regulations:

To review supplemental documents, visit Idaho Pollutant Discharge Elimination System Program Application.Exit

Additional Correspondence

You may need Adobe Reader to view files on this page. See EPA’s About PDF page to learn more.