NPDES Stormwater Permit for Ada County Highway District MS4 in Idaho
Transfer of permitting authority to Idaho. As of July 1, 2021, EPA has transferred authority to administer and enforce this permit to the Idaho Department of Environmental Quality. For more information, visit Idaho Pollutant Discharge Elimination System (IPDES) Program.
Below are EPA's National Pollutant Discharge Elimination System (NPDES) municipal separate storm sewer system (MS4) final permit and supporting documents for the Ada County Highway District (ACHD) in Idaho.
- Permit number: IDS028185
- Effective date: February 1, 2021
- Modified: June 25, 2021
- Permit expires: January 31, 2026
- NPDES Stormwater Permit, Ada County Highway District MS4, #IDS028185 (pdf)
- Appendix B1: Stormwater Management Program Template, MS4 Permit #IDS028185 (pdf)
- Appendix B2: Annual Report Form, MS4 Permit #IDS028185 (pdf)
- NPDES Permit Modification Fact Sheet, Ada County Highway District MS4, #IDS028185 (pdf)
- NPDES Permit Fact Sheet for Ada County Highway District MS4, Canyon Highway District No. 4 MS4, and Idaho Transportation Department District 3 MS4 (pdf)
- Response to Comments on Draft NPDES Permit for Ada County Highway District MS4, Idaho, #IDS028185 (pdf)