Entergy Arkansas, LLC - Union Power Station

NPDES permit AR0049140 · Major NON-POTW · effective, expires 2028-01-31 · 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.

EPA's record, 2025-09-01 to 2026-08-31

0values over a limit
0required values missing, on 0 form(s)
0of 36 forms filed late

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

Reporting

Reports are due about 25 days after each monitoring period ends (the most common figure among AR permits in EPA's filings — check your permit).

Limits in force (40)

OutfallParameterStatisticLimitMonths
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
001Oil & GreaseMO AVG <= 112.6 lb/d all year
001Oil & GreaseDAILY MX <= 168.9 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
01BpHMINIMUM >= 6 SU all year
01BpHMAXIMUM <= 9 SU all year
01BSolids, total suspendedMO AVG <= 30 mg/L all year
01BSolids, total suspendedDAILY MX <= 100 mg/L all year
01BSolids, total suspendedMO AVG <= 20 lb/d all year
01BSolids, total suspendedDAILY MX <= 66.7 lb/d all year
01BOil & GreaseMO AVG <= 15 mg/L all year
01BOil & GreaseDAILY MX <= 20 mg/L all year
01BOil & GreaseMO AVG <= 10 lb/d all year
01BOil & GreaseDAILY MX <= 13.3 lb/d all year
01BFlow, in conduit or thru treatment plantMO AVG report only all year
01BFlow, in conduit or thru treatment plantDAILY MX report only all year
01CpHMINIMUM >= 6 SU all year
01CpHMAXIMUM <= 9 SU all year
01CFlow, in conduit or thru treatment plantMO AVG report only all year
01CFlow, in conduit or thru treatment plantDAILY MX report only all year
01CChlorine, free availableMO AVG <= .2 mg/L all year
01CChlorine, free availableDAILY MX <= .5 mg/L all year
01CChlorine, free availableMO AVG <= .2 lb/d all year
01CChlorine, free availableDAILY MX <= .4 lb/d all year
TX1Whole effluent toxicity - retest #148HR MIN report only all year
TX1Whole effluent toxicity - retest #248HR MIN report only all year
TX1WET, sublethal retest #148HR MIN report only all year
TX1WET, sublethal retest #248HR MIN report only all year
TX1Whole Effluent Toxicity - Retest #348HR MIN report only all year
TX1Whole Effluent Toxicity, Sub-Lethal Retest #348HR MIN report only all year
TX1Low Flow Pass/Fail Static Renewal 48Hr Acute Daphnia pulex48HR MIN report only all year
TX1LF Pass/Fail Static Renewal 48Hr Acute Pimephales promelas48HR MIN report only all year
TX1NOAEC Lethal Statis Renewal 48 Hr Acute Daphnia pulex48HR MIN report only all year
TX1NOAEC Lethal Static Renewal 48Hr acute Pimephales promelas48HR MIN report only all year
TX1Coef Of Var Static Renewal 48Hr Acute D. pulex48HR MIN report only all year
TX1Coef Of Var Static Renewal 48Hr Acute Pimephales promelas48HR 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