Usdoi - Lower Colorado

NPDES permit AZ0025160 · Minor FEDERAL · effective, expires 2029-09-18 · 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

4values over a limit
4required values missing, on 1 form(s)
7of 40 forms filed late

Last period with anything received: 2026-07-31. Most often over: Nitrogen, ammonia total [as N] (2), BOD, 5-day, percent removal (1), Selenium, total recoverable (1).

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 (82)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. centigradeMO AVG report only all year
001Temperature, water deg. centigradeDAILY MX report only all year
001pHMINIMUM >= 6.5 SU all year
001pHMAXIMUM <= 9 SU all year
001pHMO AVG report only all year
001pHDAILY MX report only all year
001Oil & GreaseMO AVG <= 10 mg/L all year
001Oil & GreaseDAILY MX <= 15 mg/L all year
001Oil & GreaseMO AVG <= 2.3 kg/d all year
001Oil & GreaseDAILY MX <= 3.5 kg/d all year
001Nitrogen, ammonia total [as N]MO AVG report only all year
001Nitrogen, ammonia total [as N]DAILY MX report only all year
001Nitrogen, ammonia total [as N]MO AVG <= 1 Ratio all year
001Nitrogen, ammonia total [as N]DAILY MX <= 2 Ratio all year
001Cyanide, total [as CN]MO AVG report only all year
001Cyanide, total [as CN]DAILY MX report only all year
001Sulfide, total [as S]MO AVG report only all year
001Sulfide, total [as S]DAILY MX report only all year
001Hardness, total [as CaCO3]MO AVG report only all year
001Hardness, total [as CaCO3]DAILY MX report only all year
001Iron, total recoverableMO AVG <= 700 ug/L all year
001Iron, total recoverableDAILY MX <= 2000 ug/L all year
001Iron, total recoverableMO AVG <= 200 g/d all year
001Iron, total recoverableDAILY MX <= 400 g/d all year
001Selenium, total recoverableMO AVG <= 1 ug/L all year
001Selenium, total recoverableDAILY MX <= 4 ug/L all year
001Selenium, total recoverableMO AVG <= .3 g/d all year
001Selenium, total recoverableDAILY MX <= .8 g/d all year
001Zinc, total recoverableMO AVG <= 120 ug/L all year
001Zinc, total recoverableDAILY MX <= 230 ug/L all year
001Zinc, total recoverableMO AVG <= 27 g/d all year
001Zinc, total recoverableDAILY MX <= 54 g/d all year
001Cadmium, total recoverableMO AVG report only all year
001Cadmium, total recoverableDAILY MX report only all year
001Lead, total recoverableMO AVG <= 7 ug/L all year
001Lead, total recoverableDAILY MX <= 14 ug/L all year
001Lead, total recoverableMO AVG <= 1.6 g/d all year
001Lead, total recoverableDAILY MX <= 3.3 g/d all year
001Flow, in conduit or thru treatment plantMO AVG report only all year
001Flow, in conduit or thru treatment plantDAILY MX report only all year
001Chlorine, total residualMO AVG <= 9 ug/L all year
001Chlorine, total residualDAILY MX <= 17 ug/L all year
001Chlorine, total residualMO AVG <= 2.2 g/d all year
001Chlorine, total residualDAILY MX <= 3.9 g/d all year
001E. coli, colony forming units [CFU]MO AVG <= 126 CFU/100mL all year
001E. coli, colony forming units [CFU]DAILY MX <= 235 CFU/100mL all year
001Solids, total dissolvedMO AVG report only all year
001Solids, total dissolvedDAILY MX report only all year
001Solids, total dissolvedMO AVG report only all year
001Solids, total dissolvedDAILY MX report only all year
001Solids, total dissolvedDAILY MX <= 907 kg/d all year
001Solids, total dissolvedMO AVG report only all year
001Solids, total dissolvedDAILY MX report only all year
001Hydrogen sulfideMO AVG report only all year
001Hydrogen sulfideDAILY MX report only all year
001Mercury, total recoverableMO AVG <= .005 ug/L all year
001Mercury, total recoverableDAILY MX <= .02 ug/L all year
001Mercury, total recoverableMO AVG <= .001 g/d all year
001Mercury, total recoverableDAILY MX <= .004 g/d all year
001Sediment, suspendedMO MED report only all year
001TU Static 4 Day Chronic Raphidocelis subcapitata (formerly Selenastrum capricornutum)MO AVG report only all year
001TU Static 4 Day Chronic Raphidocelis subcapitata (formerly Selenastrum capricornutum)DAILY MX report only all year
001TU Static Renewal 7-Day Chronic Ceriodaphnia dubiaMO MED report only all year
001TU Static Renewal 7-Day Chronic Ceriodaphnia dubiaDAILY MX report only all year
001TU Static Renewal 7-Day Chronic Pimphales promelasMO MED report only all year
001TU Static Renewal 7-Day Chronic Pimphales promelasDAILY MX report only all year
002BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L all year
002BOD, 5-day, 20 deg. CWKLY AVG <= 45 mg/L all year
002BOD, 5-day, 20 deg. CMO AVG <= 3.4 kg/d all year
002BOD, 5-day, 20 deg. CWKLY AVG <= 5.1 kg/d all year
002Solids, total suspendedMO AVG <= 30 mg/L all year
002Solids, total suspendedWKLY AVG <= 45 mg/L all year
002Solids, total suspendedMO AVG <= 3.4 kg/d all year
002Solids, total suspendedWKLY AVG <= 5.1 kg/d all year
002Flow, in conduit or thru treatment plantMO AVG report only all year
002Flow, in conduit or thru treatment plantDAILY MX report only all year
002BOD, 5-day, percent removalMO AV MN >= 85 % all year
002Solids, suspended percent removalMO AV MN >= 85 % all year
INFBOD, 5-day, 20 deg. CMO AVG report only all year
INFBOD, 5-day, 20 deg. CWKLY AVG report only all year
INFSolids, total suspendedMO AVG report only all year
INFSolids, total suspendedWKLY AVG 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