Entergy Arkansas, LLC - Arkansas Nuclear One

NPDES permit AR0001392 · Major NON-POTW · effective, expires 2028-11-30 · 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

2values over a limit
2required values missing, on 1 form(s)
36of 138 forms filed late

Last period with anything received: 2026-07-31. Most often over: BOD, 5-day, 20 deg. C (2).

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 (120)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. fahrenheitMO AVG <= 105 deg F all year
001Temperature, water deg. fahrenheitDAILY MX <= 110 deg F all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Oil & GreaseMO AVG <= 10 mg/L all year
001Oil & GreaseDAILY MX <= 15 mg/L all year
001Oxidants, total residualDAILY MX <= .2 mg/L all year
001Oxidants, total residualDAILY MX <= 158.8 lb/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
001Coliform, fecal general30DA GEO <= 200 #/100mL May, Jun, Jul, Aug, Sep
001Coliform, fecal general30DA GEO <= 1000 #/100mL Jan, Feb, Mar, Apr, Oct, Nov, Dec
001Coliform, fecal general7 DA GEO <= 400 #/100mL May, Jun, Jul, Aug, Sep
001Coliform, fecal general7 DA GEO <= 2000 #/100mL Jan, Feb, Mar, Apr, Oct, Nov, Dec
002pHMINIMUM >= 6 SU all year
002pHMAXIMUM <= 9 SU all year
002Oxidants, free availableMO AVG <= .2 mg/L all year
002Oxidants, free availableDAILY MX <= .5 mg/L all year
002Oxidants, free availableMO AVG <= .8 lb/d all year
002Oxidants, free availableDAILY MX <= 1.9 lb/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
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 <= 15 mg/L all year
003Oil & GreaseDAILY MX <= 20 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
004pHMINIMUM >= 6 SU all year
004pHMAXIMUM <= 9 SU all year
004Solids, total suspendedMO AVG <= 30 mg/L all year
004Solids, total suspendedDAILY MX <= 100 mg/L all year
004Oil & GreaseMO AVG <= 15 mg/L all year
004Oil & GreaseDAILY MX <= 20 mg/L all year
004Flow, in conduit or thru treatment plantMO AVG report only all year
004Flow, in conduit or thru treatment plantDAILY MX report only all year
005BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L all year
005BOD, 5-day, 20 deg. CDAILY MX <= 45 mg/L 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 <= 45 mg/L all year
005Oil & GreaseMO AVG <= 15 mg/L all year
005Oil & GreaseDAILY MX <= 20 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
006pHMINIMUM >= 6 SU all year
006pHMAXIMUM <= 9 SU all year
006Solids, total suspendedMO AVG <= 30 mg/L all year
006Solids, total suspendedDAILY MX <= 100 mg/L all year
006Oil & GreaseMO AVG <= 10 mg/L all year
006Oil & GreaseDAILY MX <= 15 mg/L all year
006Flow, in conduit or thru treatment plantMO AVG report only all year
006Flow, in conduit or thru treatment plantDAILY MX report only all year
008pHMINIMUM >= 6 SU all year
008pHMAXIMUM <= 9 SU all year
008Solids, total suspendedMO AVG <= 30 mg/L all year
008Solids, total suspendedDAILY MX <= 100 mg/L all year
008Oil & GreaseMO AVG <= 15 mg/L all year
008Oil & GreaseDAILY MX <= 20 mg/L all year
008Flow, in conduit or thru treatment plantMO AVG report only all year
008Flow, in conduit or thru treatment plantDAILY MX report only all year
009pHMINIMUM >= 6 SU all year
009pHMAXIMUM <= 9 SU all year
009Oil & GreaseMO AVG <= 10 mg/L all year
009Oil & GreaseDAILY MX <= 15 mg/L all year
009Oxidants, total residualDAILY MX <= .2 mg/L all year
009Oxidants, total residualDAILY MX <= .5 lb/d all year
009Flow, in conduit or thru treatment plantMO AVG report only all year
009Flow, in conduit or thru treatment plantDAILY MX report only all year
010pHMINIMUM >= 6 SU all year
010pHMAXIMUM <= 9 SU all year
010Solids, total suspendedMO AVG <= 30 mg/L all year
010Solids, total suspendedDAILY MX <= 100 mg/L all year
010Oil & GreaseMO AVG <= 10 mg/L all year
010Oil & GreaseDAILY MX <= 15 mg/L all year
010Flow, in conduit or thru treatment plantMO AVG report only all year
010Flow, in conduit or thru treatment plantDAILY MX report only all year
011pHMINIMUM >= 6 SU all year
011pHMAXIMUM <= 9 SU all year
011Solids, total suspendedMO AVG <= 30 mg/L all year
011Solids, total suspendedDAILY MX <= 100 mg/L all year
011Oil & GreaseMO AVG <= 10 mg/L all year
011Oil & GreaseDAILY MX <= 15 mg/L all year
011Flow, in conduit or thru treatment plantMO AVG report only all year
011Flow, in conduit or thru treatment plantDAILY MX report only all year
012pHMINIMUM >= 6 SU all year
012pHMAXIMUM <= 9 SU all year
012Solids, total suspendedMO AVG <= 30 mg/L all year
012Solids, total suspendedDAILY MX <= 100 mg/L all year
012Oil & GreaseMO AVG <= 10 mg/L all year
012Oil & GreaseDAILY MX <= 15 mg/L all year
012Flow, in conduit or thru treatment plantMO AVG report only all year
012Flow, in conduit or thru treatment plantDAILY MX report only all year
013pHMINIMUM >= 6 SU all year
013pHMAXIMUM <= 9 SU all year
013Solids, total suspendedMO AVG <= 30 mg/L all year
013Solids, total suspendedDAILY MX <= 100 mg/L all year
013Oil & GreaseMO AVG <= 10 mg/L all year
013Oil & GreaseDAILY MX <= 15 mg/L all year
013Flow, in conduit or thru treatment plantMO AVG report only all year
013Flow, 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