Discharge Permits for Federal Hydroelectric Projects in the Lower Snake River

Below are EPA's National Pollutant Discharge Elimination System (NPDES) discharge permits for the following hydroelectric generating facilities on the lower Snake River operated by the U.S. Army Corps of Engineers:

• Ice Harbor Lock and Dam (WA0026816)
• Lower Monumental Lock and Dam (WA0026808)
• Little Goose Lock and Dam (WA0026786)
• Lower Granite Lock and Dam (WA0026794)

Effective date: April 1, 2022
Modified: February 16, 2024
Permits expire: March 31, 2027

Related permits: Discharge Permits for Federal Hydroelectric Projects in the Lower Columbia River

Final Permits

• NPDES Permit, Ice Harbor Lock and Dam, Lower Snake River, #WA0026816 (pdf) (422.72 KB, Modified February 16, 2024)
  Final discharge permit.
• NPDES Permit, Little Goose Lock and Dam, Lower Snake River, #WA0026786 (pdf) (411.87 KB, Modified February 16, 2024)
  Final discharge permit.
• NPDES Permit, Lower Monumental Lock and Dam, Lower Snake River, #WA0026808 (pdf) (408.31 KB, Modified February 16, 2024)
  Final discharge permit.
• NPDES Permit, Lower Granite Lock and Dam, Lower Snake River, #WA0026794 (pdf) (408.63 KB, Modified February 16, 2024)
  Final discharge permit.

Public Comments

• Response to Comments on 2023 Draft Modification to NPDES Permits for Federal Hydroelectric Facilities in the Lower Columbia and Snake Rivers (pdf) (81.52 KB, February 2024)
  EPA's responses to comments received during the public comment period from December 6, 2023, to January 4, 2024, on the proposed modification to pH monitoring frequency.
• Response to Comments on Draft NPDES Permits for Federal Hydroelectric Facilities in the Lower Snake River (pdf) (750.33 KB, September 30, 2021)
  EPA's responses to public comments received on the 2020 and 2021 draft permits.
• Public Comments on 2021 Draft NPDES Permits for Federal Hydroelectric Facilities in the Lower Columbia and Snake Rivers (pdf) (7.82 MB, March 1, 2021)
  Comments received by EPA within the public comment period from January 15 through February 16, 2021.
• Public Comments on 2020 Draft NPDES Permits for Federal Hydroelectric Facilities in the Lower Columbia and Snake Rivers (pdf) (8.4 MB)
  Comments received by EPA within the public comment period from March 18 through May 4, 2020.

Fact Sheets

• 2023 NPDES Permit Fact Sheet, Federal Hydroelectric Projects in the Lower Columbia and Snake Rivers (pdf) (194.72 KB, December 2023)
  Technical basis for proposed permit modifications.
• 2021 NPDES Permit Fact Sheet, U.S. Army Corps of Engineers Lower Snake River Hydroelectric Facilities: #WA0026816, #WA0026808, #WA0026786, #WA0026794 (pdf) (423.61 KB, January 2021)
  Technical basis for 2021 revised permits.
• 2020 NPDES Permit Fact Sheet, U.S. Army Corps of Engineers Lower Snake River Hydroelectric Facilities: #WA0026816, #WA0026808, #WA0026786, #WA0026794. (pdf) (2.01 MB, March 2020)
  Technical basis for 2020 proposed permits.