NPDES Stormwater Permit for City of Caldwell 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) permit and supporting documents for the City of Caldwell in Idaho.

Permit number: IDS028118
Effective date: December 1, 2020
Modified: June 1, 2021
Permit expires: September 30, 2025

NPDES Stormwater Permit, City of Caldwell MS4, Idaho, #IDS028118 (pdf) (June 1, 2021)
Final modified stormwater permit.
NPDES Permit Fact Sheet (2021 Modification), City of Caldwell MS4, Idaho, #IDS028118 (pdf) (April 2021)
Technical basis for permit modification.
NPDES Permit Fact Sheet, City of Caldwell MS4, Idaho, #IDS028118 (pdf) (July 2020)
Technical basis for original permit.
Response to Comments on Draft Permit for City of Caldwell MS4, Idaho, #IDS028118 (pdf) (October 2020)
EPA's responses to public comments on the July 2020 draft permit.
Appendix B1: Stormwater Management Program Template, #IDS028118 (pdf)
Optional template for creating or revising Stormwater Management Program (SWMP) document.
Appendix B2: Annual Report Form, #IDS028118 (pdf)
Format for annual report. Due no later than December 1 of each year.