CITY OF LIBBY

NPDES permit MT0030341 · Minor POTW · administratively continued, expires 2026-07-31 · 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 2026-07-31 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
0required values missing, on 0 form(s)
0of 11 forms filed late

Last period with anything received: 2026-07-31.

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 (14)

OutfallParameterStatisticLimitMonths
001Flow rateMO AVG report only all year
001Flow rateDAILY MX report only all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Solids, total suspendedMO AVG <= 30 mg/L all year
001Solids, total suspendedDAILY MX <= 45 mg/L all year
001Solids, total suspendedMO AVG <= 22.5 lb/d all year
001Solids, total suspendedDAILY MX <= 123.8 lb/d all year
001Aluminum, dissolved [as Al]MO AVG <= 1 mg/L all year
001Aluminum, dissolved [as Al]DAILY MX <= 1.5 mg/L all year
001Aluminum, dissolved [as Al]MO AVG <= 1.44 lb/d all year
001Aluminum, dissolved [as Al]DAILY MX <= 2.16 lb/d all year
001Chlorine, total residualMO AVG report only all year
001Chlorine, total residualDAILY MX <= .1 mg/L 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