CITY OF MISSOULA

NPDES permit MT0022594 · Major POTW · administratively continued, expires 2020-04-30 · 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 2020-04-30 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

6values over a limit
0required values missing, on 0 form(s)
0of 19 forms filed late

Last period with anything received: 2026-07-31. Most often over: BOD, carbonaceous [5 day, 20 C] (4), BOD, carbonaceous, percent removal (1), Phosphorus, total [as P] (1).

Reporting

Reports are due about 28 days after each monitoring period ends (the most common figure among MT permits in EPA's filings — check your permit).

Limits in force (63)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. centigradeMINIMUM report only all year
001Temperature, water deg. centigrade30DA AVG report only all year
001Temperature, water deg. centigradeMAXIMUM 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
001Oxygen, dissolved [DO]MINIMUM report only all year
001Oxygen, dissolved [DO]30DA AVG report only all year
001Oxygen, dissolved [DO]MAXIMUM report only all year
001pHDAILY MN >= 6 SU all year
001pHDAILY MX <= 9 SU all year
001Solids, total suspended30DA AVG <= 23 mg/L all year
001Solids, total suspendedMX 7D AV <= 34 mg/L all year
001Solids, total suspended30DA AVG <= 2249 lb/d all year
001Solids, total suspendedMX 7D AV <= 3374 lb/d all year
001Solids, total suspended30DA AVG report only all year
001Solids, total suspendedMX 7D AV report only all year
001Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
001Nitrogen, total [as N]30DA AVG report only Jun, Jul, Aug, Sep
001Nitrogen, total [as N]30DA AVG report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Nitrogen, total [as N]MX 7D AV report only Jun, Jul, Aug, Sep
001Nitrogen, total [as N]MX 7D AV report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Nitrogen, total [as N]30DA AVG <= 910 lb/d Jun, Jul, Aug, Sep
001Nitrogen, total [as N]30DA AVG report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Nitrogen, total [as N]MX 7D AV report only Jun, Jul, Aug, Sep
001Nitrogen, total [as N]MX 7D AV report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Nitrogen, ammonia total [as N]30DA AVG <= 3.4 mg/L all year
001Nitrogen, ammonia total [as N]MX 7D AV <= 6.9 mg/L all year
001Nitrogen, Kjeldahl, total [as N]30DA AVG report only all year
001Nitrite + Nitrate total [as N]30DA AVG report only all year
001Phosphorus, total [as P]30DA AVG report only Jun, Jul, Aug, Sep
001Phosphorus, total [as P]30DA AVG report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Phosphorus, total [as P]MX 7D AV report only Jun, Jul, Aug, Sep
001Phosphorus, total [as P]MX 7D AV report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Phosphorus, total [as P]30DA AVG <= 101 lb/d Jun, Jul, Aug, Sep
001Phosphorus, total [as P]30DA AVG report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Phosphorus, total [as P]DAILY MX report only Jun, Jul, Aug, Sep
001Phosphorus, total [as P]DAILY MX report only Jan, Feb, Mar, Apr, May, Oct, Nov, Dec
001Cyanide, total [as CN]DAILY MX report only all year
001Iron, total recoverableMO AVG <= 950 ug/L all year
001Iron, total recoverableDAILY MX <= 1640 ug/L all year
001Lead, total recoverableMO AVG <= 2.6 ug/L all year
001Lead, total recoverableDAILY MX <= 2.9 ug/L all year
001Copper, total recoverableMO AVG <= 11 ug/L all year
001Copper, total recoverableDAILY MX <= 13.6 ug/L all year
001E. coli, MTEC-MF30DAVGEO <= 630 CFU/100mL Jan, Feb, Mar, Nov, Dec
001E. coli, MTEC-MF30DAVGEO <= 126 CFU/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
001E. coli, MTEC-MF7I <= 1260 CFU/100mL Jan, Feb, Mar, Nov, Dec
001E. coli, MTEC-MF7I <= 252 CFU/100mL Apr, May, Jun, Jul, Aug, Sep, Oct
001Chlorine, total residual30DA AVG <= .011 mg/L all year
001Chlorine, total residualDAILY MX <= .019 mg/L all year
001BOD, carbonaceous [5 day, 20 C]30DA AVG <= 19 mg/L all year
001BOD, carbonaceous [5 day, 20 C]MX 7D AV <= 30 mg/L all year
001BOD, carbonaceous [5 day, 20 C]30DA AVG <= 1874 lb/d all year
001BOD, carbonaceous [5 day, 20 C]MX 7D AV <= 2999 lb/d all year
001BOD, carbonaceous [5 day, 20 C]30DA AVG report only all year
001BOD, carbonaceous [5 day, 20 C]MX 7D AV report only all year
001BOD, carbonaceous, percent removalMINIMUM >= 85 % all year
001Solids, suspended percent removalMINIMUM >= 85 % all year
001Oil and grease visualSINGSAMP report only 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

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