MONTANA SULPHUR AND CHEMICAL CO

NPDES permit MT0000230 · Minor NON-POTW · administratively continued, expires 2025-12-31 · 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.

This permit expired on 2025-12-31 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)
1of 19 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 (27)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. fahrenheitDAILY MX <= 95 deg F all year
001Flow rateMO AVG report only all year
001Flow rateDAILY MX report only all year
001pHDAILY MN >= 6 SU all year
001pHDAILY MX <= 9 SU all year
001Solids, total suspendedAVERAGE report only all year
001Solids, total suspendedDAILY MX report only all year
001Solids, total suspendedDAILY MX <= 30 mg/L all year
001Solids, total suspendedAVERAGE report only all year
001Solids, total suspendedDAILY MX report only all year
001Oil & GreaseDAILY MX <= 10 mg/L all year
001Nitrogen, total [as N]MO AVG report only Jul, Aug, Sep, Oct
001Nitrite + Nitrate total [as N]MO AVG report only Jul, Aug, Sep, Oct
001Phosphorus, total [as P]MO AVG report only Jul, Aug, Sep, Oct
001Sulfate, total [as SO4]VALUE report only all year
001Iron, total recoverableMO AVG report only all year
001Iron, total recoverableDAILY MX report only all year
001Aluminum, dissolved [as Al]MO AVG report only all year
001Cadmium, total recoverableMO AVG report only all year
001Lead, total recoverableMO AVG report only all year
001Nitrogen, total KjeldahlMO AVG report only Jul, Aug, Sep, Oct
001Chlorine, total residualMO AVG <= 11 mg/L all year
001Chlorine, total residualDAILY MX <= 19 mg/L all year
001Hydrogen sulfideVALUE report only all year
001Oil and grease visualVALUE report only all year
001Pass/Fail Static Renewal 48Hr Acute Ceriodaphnia dubiaVALUE report only all year
001Pass/Fail Static Renewal 96Hr Acute Pimephales PromelasVALUE 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