GREAT FALLS TOWN OF

NPDES permit SC0021211 · Major POTW · effective, expires 2029-10-31 · 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

2values over a limit
62required values missing, on 2 form(s)
5of 18 forms filed late

Last period with anything received: 2026-07-31. Most often over: Solids, total suspended (2).

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 (47)

OutfallParameterStatisticLimitMonths
001Oxygen, dissolved [DO]MINIMUM >= 5 mg/L all year
001BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L all year
001BOD, 5-day, 20 deg. CWKLY AVG <= 45 mg/L all year
001BOD, 5-day, 20 deg. CMO AVG <= 350 lb/d all year
001BOD, 5-day, 20 deg. CWKLY AVG <= 525 lb/d all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 8.5 SU all year
001Solids, total suspendedMO AVG <= 30 mg/L all year
001Solids, total suspendedWKLY AVG <= 45 mg/L all year
001Solids, total suspendedMO AVG <= 350 lb/d all year
001Solids, total suspendedWKLY AVG <= 525 lb/d all year
001Nitrogen, total [as N]MO AVG report only all year
001Nitrogen, total [as N]WKLY AVG report only all year
001Nitrogen, total [as N]MO AVG report only all year
001Nitrogen, total [as N]WKLY AVG report only all year
001Phosphorus, total [as P]MO AVG <= 2 mg/L all year
001Phosphorus, total [as P]WKLY AVG <= 3 mg/L all year
001Phosphorus, total [as P]MO AVG <= 12 lb/d all year
001Phosphorus, total [as P]WKLY AVG <= 18 lb/d all year
001Copper, total [as Cu]MO AVG report only all year
001Copper, total [as Cu]DAILY MX report only all year
001Copper, total [as Cu]MO AVG report only all year
001Copper, total [as Cu]DAILY MX report only all year
001Lead, total [as Pb]MO AVG report only all year
001Lead, total [as Pb]DAILY MX report only all year
001Lead, total [as Pb]MO AVG report only all year
001Lead, total [as Pb]DAILY MX report only all year
001Polychlorinated biphenyls [PCBs]MO AVG report only all year
001Polychlorinated biphenyls [PCBs]DAILY MX report only all year
001Polychlorinated biphenyls [PCBs]MO AVG report only all year
001Polychlorinated biphenyls [PCBs]DAILY MX report only all year
001Flow, in conduit or thru treatment plantMO AVG report only all year
001Flow, in conduit or thru treatment plantWKLY AVG report only all year
001Chlorine, total residualMO AVG <= .5 mg/L all year
001Chlorine, total residualDAILY MX <= 1 mg/L all year
001Chlorine, total residualMO AVG <= 5.8 lb/d all year
001Chlorine, total residualDAILY MX <= 11.7 lb/d all year
001E. coli30DAVGEO <= 126 MPN/100mL all year
001E. coliDAILY MX <= 349 MPN/100mL all year
001E. coli30DAVGEO <= 126 MPN/100mL all year
001E. coliDAILY MX <= 800 MPN/100mL all year
001BOD, 5-day, percent removalMO AV MN >= 85 % all year
001Solids, suspended percent removalMO AV MN >= 85 % all year
001LC50 Static 48Hr Acute Ceriodaphnia dubiaDAILY MN report only all year
001%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiaMO AVG <= 25 % all year
001%Effect Static Renewal 7 Day Chronic Ceriodaphnia dubiaDAILY MX <= 40 % all year
001IC25 Static Renewal 7 Day Chronic Ceriodaphnia dubiaDAILY MN 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