USCOE LIBBY DAM

NPDES permit MT0022390 · Minor FEDERAL · effective, expires 2026-09-30 · EPA's file as of 2026-09-19

Check this month's numbers before you file
Watch this permit — $79 a month. Every Monday, from EPA's newest files: the next report due and when, whether EPA's file holds your last one, any change to this permit's limits or status, and the renewal date.

EPA's record, 2025-09-01 to 2026-08-31

0values over a limit
0required values missing, on 0 form(s)
9of 85 forms filed late

Last period with anything received: 2026-07-31.

Reporting

Reports are due about 28 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (68)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. centigradeMINIMUM report only all year
001Temperature, water deg. centigradeMO AVG report only all year
001Temperature, water deg. centigradeMAXIMUM report only all year
001Flow rateMO AVG report only all year
001Flow rateDAILY MX report only all year
001BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L all year
001BOD, 5-day, 20 deg. CDAILY MX <= 45 mg/L all year
001BOD, 5-day, 20 deg. CMO AVG <= 1.5 lb/d all year
001BOD, 5-day, 20 deg. CMX WK AV <= 2.25 lb/d all year
001BOD, 5-day, 20 deg. CSINGSAMP report only all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Solids, total suspendedMO AVG <= 30 mg/L all year
001Solids, total suspendedMX WK AV <= 45 mg/L all year
001Solids, total suspendedMO AVG <= 1.5 lb/d all year
001Solids, total suspendedMX WK AV <= 2.25 lb/d all year
001Solids, total suspendedSINGSAMP report only all year
001Oil and grease, hexane extr methodSINGSAMP report only all year
001Oil and grease, hexane extr methodDAILY MX report only all year
001Nitrogen, total [as N]SINGSAMP report only all year
001Nitrogen, total [as N]SINGSAMP report only all year
001Nitrogen, ammonia total [as N]SINGSAMP report only all year
001Nitrogen, Kjeldahl, total [as N]SINGSAMP report only all year
001Nitrite + Nitrate total [as N]SINGSAMP report only all year
001Phosphorus, total [as P]SINGSAMP report only all year
001Phosphorus, total [as P]SINGSAMP report only all year
001E. coli, MTEC-MFMOAV GEO <= 630 #/100mL Jan, Feb, Mar, Nov, Dec
001E. coli, MTEC-MFMOAV GEO <= 126 #/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
001E. coli, MTEC-MFDAILY MX <= 1260 #/100mL Jan, Feb, Mar, Nov, Dec
001E. coli, MTEC-MFDAILY MX <= 252 #/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
001BOD, 5-day, percent removalMINIMUM >= 85 % all year
001Solids, suspended percent removalMINIMUM >= 85 % all year
002Flow rateMO AVG report only all year
002Flow rateDAILY MX report only all year
002pHMINIMUM report only all year
002pHMO AVG report only all year
002pHMAXIMUM report only all year
002Oil and grease, hexane extr methodDAILY MX report only Mar, Jun, Sep, Dec
003Temperature, water deg. fahrenheitDAILY MN report only all year
003Temperature, water deg. fahrenheitDAILY MN report only all year
003Temperature, water deg. fahrenheitDAILY MN report only all year
003Temperature, water deg. fahrenheitDAILY MN report only all year
003Temperature, water deg. fahrenheitDAILY MN report only all year
003Temperature, water deg. fahrenheitMO AVG report only all year
003Temperature, water deg. fahrenheitMO AVG report only all year
003Temperature, water deg. fahrenheitMO AVG report only all year
003Temperature, water deg. fahrenheitMO AVG report only all year
003Temperature, water deg. fahrenheitMO AVG report only all year
003Temperature, water deg. fahrenheitDAILY MX report only all year
003Temperature, water deg. fahrenheitDAILY MX report only all year
003Temperature, water deg. fahrenheitDAILY MX report only all year
003Temperature, water deg. fahrenheitDAILY MX report only all year
003Temperature, water deg. fahrenheitDAILY MX report only all year
003Flow rateMO AVG report only all year
003Flow rateMO AVG report only all year
003Flow rateMO AVG report only all year
003Flow rateMO AVG report only all year
003Flow rateMO AVG report only all year
003Flow rateDAILY MX report only all year
003Flow rateDAILY MX report only all year
003Flow rateDAILY MX report only all year
003Flow rateDAILY MX report only all year
003Flow rateDAILY MX report only all year
003Oil and grease, hexane extr methodSINGGRAB report only Mar, Jun, Sep, Dec
003Oil and grease, hexane extr methodSINGGRAB report only Mar, Jun, Sep, Dec
003Oil and grease, hexane extr methodSINGGRAB report only Mar, Jun, Sep, Dec
003Oil and grease, hexane extr methodSINGGRAB report only Mar, Jun, Sep, Dec
003Oil and grease, hexane extr methodSINGGRAB report only Mar, Jun, Sep, Dec

Built from EPA's ECHO bulk files. EPA's file, not the permit document, is the source: read your permit. Check a report before you file it · All states