US ARMY CORPS OF ENGINEERS

NPDES permit MT0031551 · Minor FEDERAL · administratively continued, expires 2024-02-29 · 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 2024-02-29 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
0required values missing, on 0 form(s)
0of 144 forms filed late

Last period with anything received: 2026-08-31.

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 (55)

OutfallParameterStatisticLimitMonths
001Flow rateMO AVG report only all year
001Flow rateDAILY MX report only all year
001pHMINIMUM >= 6.5 SU all year
001pHMAXIMUM <= 9 SU all year
001Oil and grease, hexane extr methodQB report only all year
002Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
002Temperature, water deg. fahrenheitMO AVG report only all year
002Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
002Flow rateMO AVG report only all year
002Flow rateDAILY MX report only all year
004Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
004Temperature, water deg. fahrenheitMO AVG report only all year
004Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
004Flow rateMO AVG report only all year
004Flow rateDAILY MX report only all year
005Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
005Temperature, water deg. fahrenheitMO AVG report only all year
005Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
005Flow rateMO AVG report only all year
005Flow rateDAILY MX report only all year
006Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
006Temperature, water deg. fahrenheitMO AVG report only all year
006Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
006Flow rateMO AVG report only all year
006Flow rateDAILY MX report only all year
007Flow rate30DA AVG report only all year
007Flow rateDAILY MX report only all year
007pHMINIMUM >= 6.5 SU all year
007pHMAXIMUM <= 9 SU all year
007Oil and grease, hexane extr methodQB <= 10 mg/L all year
010Flow rate30DA AVG report only all year
010Flow rateDAILY MX report only all year
010pHMINIMUM >= 6.5 SU all year
010pHMAXIMUM <= 9 SU all year
010Oil and grease, hexane extr methodQB <= 10 mg/L all year
012Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
012Temperature, water deg. fahrenheitMO AVG report only all year
012Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
012Flow rateMO AVG report only all year
012Flow rateDAILY MX report only all year
013Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
013Temperature, water deg. fahrenheitMO AVG report only all year
013Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
013Flow rateMO AVG report only all year
013Flow rateDAILY MX report only all year
014Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
014Temperature, water deg. fahrenheitMO AVG report only all year
014Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
014Flow rateMO AVG report only all year
014Flow rateDAILY MX report only all year
021Temperature, water deg. fahrenheitMO MIN >= 32 deg F all year
021Temperature, water deg. fahrenheitMO AVG report only all year
021Temperature, water deg. fahrenheitMO MAX <= 80 deg F all year
021Flow rateMO AVG report only all year
021Flow rateDAILY MX 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