Entergy Arkansaas, LLC - Lake Catherine Plant

NPDES permit AR0001147 · Major NON-POTW · effective, expires 2031-04-30 · 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

0values over a limit
0required values missing, on 0 form(s)
0of 58 forms filed late

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

Reporting

Reports are due about 25 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (43)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. fahrenheitINST MAX <= 95 deg F all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Flow, in conduit or thru treatment plantMO AVG <= 425 MGD all year
001Flow, in conduit or thru treatment plantDAILY MX <= 476 MGD all year
001Chlorine, total residualDAILY MX <= .2 mg/L all year
001Chlorine, total residualDAILY MX <= 66.2 lb/d all year
001Chlorine, free availableMO AVG <= .2 mg/L all year
001Chlorine, free availableDAILY MX <= .5 mg/L all year
001Chlorine, free availableMO AVG <= 59.1 lb/d all year
001Chlorine, free availableDAILY MX <= 165.4 lb/d all year
003pHMINIMUM >= 6 SU all year
003pHMAXIMUM <= 9 SU all year
003Solids, total suspendedMO AVG <= 30 mg/L all year
003Solids, total suspendedDAILY MX <= 100 mg/L all year
003Oil & GreaseMO AVG <= 10 mg/L all year
003Oil & GreaseDAILY MX <= 15 mg/L all year
003Flow, in conduit or thru treatment plantMO AVG report only all year
003Flow, in conduit or thru treatment plantDAILY MX report only all year
005pHMINIMUM >= 6 SU all year
005pHMAXIMUM <= 9 SU all year
005Solids, total suspendedMO AVG <= 30 mg/L all year
005Solids, total suspendedDAILY MX <= 100 mg/L all year
005Oil & GreaseMO AVG <= 10 mg/L all year
005Oil & GreaseDAILY MX <= 15 mg/L all year
005Flow, in conduit or thru treatment plantMO AVG report only all year
005Flow, in conduit or thru treatment plantDAILY MX report only all year
TX1Whole effluent toxicity - retest #17 DA MIN report only all year
TX1Whole effluent toxicity - retest #27 DA MIN report only all year
TX1WET, sublethal retest #17 DA MIN report only all year
TX1WET, sublethal retest #27 DA MIN report only all year
TX1Whole Effluent Toxicity - Retest #37 DA MIN report only all year
TX1Whole Effluent Toxicity, Sub-Lethal Retest #37 DA MIN report only all year
TX1Pass/Fail Static Renewal 7 Day Chronic Ceriodaphnia dubia7 DA MIN report only all year
TX1Pass/Fail Static Renewal 7Day Chronic Pimephales promelas7 DA MIN report only all year
TX1Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Ceriodaphnia dubia7 DA MIN report only all year
TX1Low Flow Pass/Fail Survival Test Static Renewal 7 Day Chronic Pimephales promelas7 DA MIN report only all year
TX1NOEC Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia7 DA MIN report only all year
TX1NOEC Lethal Static Renewal 7 Day Chronic Pimephales promelas7 DA MIN report only all year
TX1NOEC Sub-Lethal Static Renewal 7 Day Chronic Ceriodaphnia dubia7 DA MIN report only all year
TX1NOEC Sub-Lethal Static Renewal 7 Day Chronic Pimephales promelas7 DA MIN report only all year
TX1Coef Of Var Static Renewal 7Day Chronic Ceriodaphnia dubia7 DA MIN report only all year
TX1Coef Of Var Static Renewal 7Day Chronic Pimephales promelas7 DA MIN 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