CITY OF LIBBY

NPDES permit MT0020494 · Major POTW · administratively continued, expires 2021-06-30 · 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.

This permit expired on 2021-06-30 and is administratively continued: its last limits keep applying until a new permit is issued, and EPA still expects the reports.

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

0values over a limit
2required values missing, on 1 form(s)
7of 23 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 (48)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. fahrenheitDAILY MN report only all year
001Temperature, water deg. fahrenheitDAILY MX report only all year
001Flow rate30DA AVG report only all year
001Flow rateDAILY MX report only all year
001Flow rate30DA AVG report only all year
001Flow rateDAILY MX report only all year
001BOD, 5-day, 20 deg. C30DA AVG <= 30 mg/L all year
001BOD, 5-day, 20 deg. C7 DA AVG <= 45 mg/L all year
001BOD, 5-day, 20 deg. C30DA AVG <= 117 lb/d all year
001BOD, 5-day, 20 deg. C7 DA AVG <= 192 lb/d all year
001BOD, 5-day, 20 deg. C30DA AVG report only all year
001pHDAILY MN >= 6 SU all year
001pHDAILY MX <= 9 SU all year
001Solids, total suspended30DA AVG <= 30 mg/L all year
001Solids, total suspended7 DA AVG <= 45 mg/L all year
001Solids, total suspended30DA AVG <= 123 lb/d all year
001Solids, total suspended7 DA AVG <= 192 lb/d all year
001Solids, total suspended30DA AVG report only all year
001Oil and grease, hexane extr method30DA AVG report only all year
001Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
001Nitrogen, total [as N]30DA AVG report only all year
001Nitrogen, total [as N]30DA AVG report only all year
001Nitrogen, ammonia total [as N]30DA AVG report only all year
001Nitrogen, ammonia total [as N]DAILY MX report only all year
001Nitrogen, Kjeldahl, total [as N]30DA AVG report only all year
001Nitrogen, Kjeldahl, total [as N]DAILY MX report only all year
001Nitrite + Nitrate total [as N]30DA AVG report only all year
001Nitrite + Nitrate total [as N]DAILY MX report only all year
001Phosphorus, total [as P]30DA AVG report only all year
001Phosphorus, total [as P]30DA AVG report only all year
001Zinc, total recoverableQRTR AVG report only all year
001Copper, total recoverableQRTR AVG report only all year
001E. coli, MTEC-MF30DAVGEO <= 126 CFU/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
001E. coli, MTEC-MF30DAVGEO <= 630 CFU/100mL Jan, Feb, Mar, Nov, Dec
001E. coli, MTEC-MF7I <= 252 CFU/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
001E. coli, MTEC-MF7I <= 1260 CFU/100mL Jan, Feb, Mar, Nov, Dec
001Chlorine, total residualDAILY MX <= .5 mg/L all year
001BOD, 5-day, percent removalMO AV MN >= 85 % all year
001Solids, suspended percent removalMO AV MN >= 85 % all year
001Pass/Fail Static 48Hr Acute Ceriodaphnia dubiaVALUE <= 0 pass=0;fail=1 all year
001Pass/Fail Static 96 Hr Acute Pimephales PromelasVALUE <= 0 pass=0;fail=1 all year
RIVTemperature, water deg. fahrenheitQC report only all year
RIVTemperature, water deg. fahrenheitQB report only all year
RIVpHQRTR AVG report only all year
RIVNitrogen, ammonia total [as N]QRTR AVG report only all year
RIVHardness, total [as CaCO3]QRTR AVG report only all year
RIVZinc, total recoverableQB report only all year
RIVCopper, total recoverableQC report only all year

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