Passage Data · Check a report · Use it from your AI

PacifiCorp Merwin Hydroelectric Project

Electric Services, Ariel, Washington. NPDES permit WA0041165, in force until Sep 30, 2028. Last 12 months: no values over a limit. Source: EPA ECHO, Oct 22, 2026.

Reports due
About 15 days after each period: outfall 001 form MM monthly (6 values), outfall 002 form MM monthly (6 values), outfall 003 form MM monthly (6 values), outfall AWS form MM monthly (7 values), outfall OWS form QQ quarterly (2 values), outfall PHS1 form MM monthly (7 values), and 1 more form
Renewal application due
Apr 3, 2028 · 180 days before expiry; your permit may set another date
Last report on file
September 2026
Oct 2024 – Sep 2025
0 values over a limit, 0 required values missing, 6 of 76 reports late

Limits in force (41)

ParameterStatisticLimitMonthsOutfall
Temperature, water deg. centigradedaily maximumreport only (deg C) (alert, not enforceable)all year001
Temperature, water deg. centigrademonthly averagereport only (deg C) (alert, not enforceable)all year001
pHdaily minimum≥ 6.5 SUall year001
pHdaily maximum≤ 8.5 SUall year001
Flowdaily maximumreport only (MGD) (alert, not enforceable)all year001
Flowmonthly averagereport only (MGD) (alert, not enforceable)all year001
Temperature, water deg. centigradedaily maximumreport only (deg C) (alert, not enforceable)all year002
Temperature, water deg. centigrademonthly averagereport only (deg C) (alert, not enforceable)all year002
pHdaily minimum≥ 6.5 SUall year002
pHdaily maximum≤ 8.5 SUall year002
Flowdaily maximumreport only (MGD) (alert, not enforceable)all year002
Flowmonthly averagereport only (MGD) (alert, not enforceable)all year002
Temperature, water deg. centigradedaily maximumreport only (deg C) (alert, not enforceable)all year003
Temperature, water deg. centigrademonthly averagereport only (deg C) (alert, not enforceable)all year003
pHdaily minimum≥ 6.5 SUall year003
pHdaily maximum≤ 8.5 SUall year003
Flowdaily maximumreport only (MGD) (alert, not enforceable)all year003
Flowmonthly averagereport only (MGD) (alert, not enforceable)all year003
Temperature, water deg. centigradedaily maximumreport only (deg C) (alert, not enforceable)all yearAWS
Temperature, water deg. centigrademonthly averagereport only (deg C) (alert, not enforceable)all yearAWS
pHdaily minimum≥ 6.5 SUall yearAWS
pHdaily maximum≤ 8.5 SUall yearAWS
Oil and grease [soxhlet extr.] tot.monthly averagereport only (mg/L) (alert, not enforceable)all yearAWS
Flowdaily maximumreport only (MGD) (alert, not enforceable)all yearAWS
Flowmonthly averagereport only (MGD) (alert, not enforceable)all yearAWS
Oil & Greasedaily maximumreport only (mg/L) (alert, not enforceable)all yearOWS
Oil & Greasemonthly averagereport only (mg/L) (alert, not enforceable)all yearOWS
Temperature, water deg. centigradedaily maximumreport only (deg C) (alert, not enforceable)all yearPHS1
Temperature, water deg. centigrademonthly averagereport only (deg C) (alert, not enforceable)all yearPHS1
pHdaily minimum≥ 6.5 SUall yearPHS1
pHdaily maximum≤ 8.5 SUall yearPHS1
Oil and grease [soxhlet extr.] tot.monthly averagereport only (mg/L) (alert, not enforceable)all yearPHS1
Flowdaily maximumreport only (MGD) (alert, not enforceable)all yearPHS1
Flowmonthly averagereport only (MGD) (alert, not enforceable)all yearPHS1
Temperature, water deg. centigradedaily maximumreport only (deg C) (alert, not enforceable)all yearPHS2
Temperature, water deg. centigrademonthly averagereport only (deg C) (alert, not enforceable)all yearPHS2
pHdaily minimum≥ 6.5 SUall yearPHS2
pHdaily maximum≤ 8.5 SUall yearPHS2
Oil and grease [soxhlet extr.] tot.monthly averagereport only (mg/L) (alert, not enforceable)all yearPHS2
Flowdaily maximumreport only (MGD) (alert, not enforceable)all yearPHS2
Flowmonthly averagereport only (MGD) (alert, not enforceable)all yearPHS2

How strict are these limits?

Cited limits by parameter: Washington's rules and the federal ones.

Same industry: the 21 Electric Services permits in Washington.

Check this month's numbers Email me before each report is due

· Save this facility as a site · Superfund sites nearby · Your permits on one board

On EPA ECHO: Facility report · DMR history

Your permit document is the final word. As JSON: /api/v1/permits/WA0041165 · MCP: https://passage-data.com/mcp