NPDES WA0041165 · Clean Water Act
PACIFICORP MERWIN HYDROELECTRIC PROJECT, Ariel, WA: NPDES WA0041165 discharge permit, effluent exceedances, inspections, penalties
PACIFICORP MERWIN HYDROELECTRIC PROJECT, Ariel, Washington: Individual permit WA0041165, held by PacifiCorp Merwin Hydroelectric Project; Effective; issued August 31, 2023, term to September 30, 2028, by State.
3 of the 5 pollutants listed for NPDES WA0041165 have no violation or effluent exceedance.
- pH: 12 limits, 4 violations of any kind, 4 effluent exceedances, latest May 31, 2024.
- Oil and grease [soxhlet extr.] tot.: 3 limits, 1 violation of any kind.
- Temperature, water deg. centigrade: 12 limits.
- Flow: 12 limits.
- Oil & Grease: 2 limits.
- September 15, 2026: Evaluation (S).
- April 9, 2026: Letter of Violation/ Warning Letter (State).
PACIFICORP MERWIN HYDROELECTRIC PROJECT among its neighbors
67 discharge permits are in the Lewis River subwatershed (HUC 170800020606); WA0041165 is one. Its county: 174, 5 major; WA0041165 is minor permit.
Other permits in the Lewis River subwatershed (HUC 170800020606)
- 50TH AVENUE ROUNDABOUT AND PIONEER STREET WIDENING, Ridgefield: WAR313757, minor, term to 2025-12-31
- 50TH PLACE SUBDIVISION, Ridgefield: WAR314894, minor, term to 2025-12-31
- ALLIANCE INDUSTRIAL GROUP, INC., Ridgefield: WAR315151, minor, term to 2029-12-31
- CANTERBURY TRAIL SUBDIVISION, Ridgefield: WAR127187, minor, term to 2015-12-31
- CIRCLE C ROCK PRODUCTS, Ridgefield: WAG501137, minor, term to 2026-03-31
- DIAMOND MEADOWS SUBDIVISION RIDGEFIELD, Ridgefield: WAR012258, minor, term to 2015-12-31
- DISCOVERY RIDGE LOTS 8-11, Ridgefield: WAR314944, minor, term to 2025-12-31
- DISCOVERY RIDGE PH3B, Ridgefield: WAR312971, minor, term to 2025-12-31
- DISCOVERY RIDGE PHASE 3, Ridgefield: WAR315760, minor, term to 2030-12-31
- DISCOVERY RIDGE SUBDIVISION, Ridgefield: WAR302161, minor, term to 2015-12-31
Identity
| Facility | PACIFICORP MERWIN HYDROELECTRIC PROJECT |
|---|---|
| Permittee | PacifiCorp Merwin Hydroelectric Project |
| NPDES ID | WA0041165 |
| Status | Effective |
| Type | Individual permit |
| Class | Minor |
| Facility type | Non-POTW |
| Issued | August 31, 2023 |
| Expires | September 30, 2028 |
| Agency | State |
| Address | Ariel, WA 98603 |
| Subwatershed | Lewis River (HUC 170800020606) |
| SIC | 4911 – Electric Services |
| Other EPA IDs (FRS) | RCRA handler WAD988471645 |
NPDES WA0041165: effluent limits and exceedances
PACIFICORP MERWIN HYDROELECTRIC PROJECT (NPDES WA0041165): 5 pollutants on file, 5 limited; 2 with a violation of any kind, 1 with an exceedance.
| Pollutant | Limits | Violations | Exceedances | Latest | Largest, as filed |
|---|---|---|---|---|---|
| pH | 12 | 4 | 4 | May 31, 2024 | |
| Oil and grease [soxhlet extr.] tot. | 3 | 1 | 0 | ||
| Temperature, water deg. centigrade | 12 | 0 | 0 | ||
| Flow | 12 | 0 | 0 | ||
| Oil & Grease | 2 | 0 | 0 |
NPDES WA0041165: inspections, violations and enforcement
NPDES WA0041165: 1 inspection
| Date | What EPA recorded | Agency |
|---|---|---|
| September 15, 2026 | Evaluation | S |
NPDES WA0041165: 1 informal enforcement action
| Date | What EPA recorded | Agency |
|---|---|---|
| April 9, 2026 | Letter of Violation/ Warning Letter | State |
NPDES WA0041165 (PACIFICORP MERWIN HYDROELECTRIC PROJECT): no single-event violation and formal enforcement action on file.
Watch NPDES WA0041165
NPDES WA0041165: one email when its EPA record changes — $99/month.
Permits near NPDES WA0041165
NPDES WA0041165: 5 pollutant rows, 2 dated events; ICIS-NPDES download, loaded October 14, 2026.