ENTERGY MISS INC, GRAND GULF NUCLEAR STATION

NPDES permit MS0029521 · 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)
9of 96 forms filed late

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

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 (89)

OutfallParameterStatisticLimitMonths
001Temperature, water deg. fahrenheitMO AVG report only all year
001Temperature, water deg. fahrenheitDAILY MX report only all year
001pHMINIMUM >= 6 SU all year
001pHMAXIMUM <= 9 SU all year
001Zinc, total recoverableMO AVG <= 1 mg/L all year
001Zinc, total recoverableDAILY MX <= 1 mg/L all year
001Chromium, total recoverableMO AVG <= .2 mg/L all year
001Chromium, total recoverableDAILY MX <= .2 mg/L 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, free availableMO AVG <= .2 mg/L all year
001Chlorine, free availableDAILY MX <= .5 mg/L all year
001Chlorination durationDAILY MX <= 120 min all year
004Zinc, total recoverableMO AVG <= 1 mg/L all year
004Zinc, total recoverableDAILY MX <= 1 mg/L all year
004Chromium, total recoverableMO AVG <= .2 mg/L all year
004Chromium, total recoverableDAILY MX <= .2 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
004Chlorine, free availableMO AVG <= .2 mg/L all year
004Chlorine, free availableDAILY MX <= .5 mg/L all year
004Chlorination durationDAILY MX <= 120 min all year
005Zinc, total recoverableMO AVG <= 1 mg/L all year
005Zinc, total recoverableDAILY MX <= 1 mg/L all year
005Chromium, total recoverableMO AVG <= .2 mg/L all year
005Chromium, total recoverableDAILY MX <= .2 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
005Chlorine, free availableMO AVG <= .2 mg/L all year
005Chlorine, free availableDAILY MX <= .5 mg/L all year
005Chlorination durationDAILY MX <= 120 min all year
006Solids, total suspendedMO AVG <= 30 mg/L all year
006Solids, total suspendedDAILY MX <= 100 mg/L all year
006Oil & GreaseMO AVG <= 15 mg/L all year
006Oil & GreaseDAILY MX <= 20 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
007Solids, total suspendedMO AVG <= 30 mg/L all year
007Solids, total suspendedDAILY MX <= 100 mg/L all year
007Oil & GreaseMO AVG <= 15 mg/L all year
007Oil & GreaseDAILY MX <= 20 mg/L all year
007Flow, in conduit or thru treatment plantMO AVG report only all year
007Flow, in conduit or thru treatment plantDAILY MX report only all year
007Chlorine, total residualMO AVG report only all year
007Chlorine, total residualDAILY MX report only all year
010BOD, 5-day, 20 deg. CMO AVG <= 30 mg/L all year
010BOD, 5-day, 20 deg. CDAILY MX <= 45 mg/L 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 <= 45 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
010Chlorine, total residualMO AVG report only all year
010Chlorine, total residualDAILY MX <= .5 mg/L all year
010E. coliMO AVG <= 126 #/100mL Jan, Feb, Mar, Apr, Nov, Dec
010E. coliDAILY MX <= 410 #/100mL Jan, Feb, Mar, Apr, Nov, Dec
011Solids, total suspendedMO AVG report only all year
011Solids, total suspendedDAILY MX <= 30 mg/L all year
011Oil & GreaseMO AVG <= 15 mg/L all year
011Oil & GreaseDAILY MX <= 20 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
013pHMINIMUM report only all year
013pHMAXIMUM report only all year
013Solids, total suspendedANNL AVG report only all year
013Solids, total suspendedANNL MAX report only all year
013Zinc, total recoverableQRTR AVG report only all year
013Zinc, total recoverableQB <= .065 mg/L all year
013Flow, in conduit or thru treatment plantANNL AVG report only all year
013Flow, in conduit or thru treatment plantANNL MAX report only all year
014pHMINIMUM >= 6 SU all year
014pHMAXIMUM <= 9 SU all year
014Solids, total suspendedANNL AVG report only all year
014Solids, total suspendedANNL MAX report only all year
014Zinc, total recoverableQRTR AVG report only all year
014Zinc, total recoverableQB <= .065 mg/L all year
014Flow, in conduit or thru treatment plantANNL AVG report only all year
014Flow, in conduit or thru treatment plantANNL MAX report only all year
016pHMINIMUM >= 6 SU all year
016pHMAXIMUM <= 9 SU all year
016Solids, total suspendedANNL AVG <= 30 mg/L all year
016Solids, total suspendedANNL MAX <= 100 mg/L all year
016Oil & GreaseANNL AVG <= 15 mg/L all year
016Oil & GreaseANNL MAX <= 20 mg/L all year
016Flow, in conduit or thru treatment plantANNL AVG report only all year
016Flow, in conduit or thru treatment plantANNL MAX report only all year
016Chlorine, total residualANNL AVG report only all year
016Chlorine, total residualANNL MAX <= .5 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