Ak Steel Corporation Middletown Works

NPDES permit OH0009997 · Major NON-POTW · effective, expires 2027-02-28 · 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

1values over a limit
20required values missing, on 10 form(s)
0of 190 forms filed late

Last period with anything received: 2026-07-31. Most often over: Zinc, total [as Zn] (1).

Reporting

Reports are due about 20 days after each monitoring period ends (read off this permit's own late-day counts in EPA's filings).

Limits in force (209)

OutfallParameterStatisticLimitMonths
001Solids, total suspendedMO AVG <= 2270 kg/d all year
001Solids, total suspendedDAILY MX <= 7073 kg/d all year
001Oil and grease, hexane extr methodMO AVG <= 104 kg/d all year
001Oil and grease, hexane extr methodDAILY MX <= 296 kg/d all year
001Lead, total [as Pb]MO AVG <= 3.18 kg/d all year
001Lead, total [as Pb]DAILY MX <= 10.5 kg/d all year
001Zinc, total [as Zn]MO AVG <= 3.43 kg/d all year
001Zinc, total [as Zn]DAILY MX <= 15.7 kg/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
002pHDAILY MN >= 6.5 SU all year
002pHDAILY MX <= 9 SU all year
002Solids, total suspendedMO AVG report only all year
002Solids, total suspendedDAILY MX report only all year
002Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
002Nitrogen, ammonia total [as N]MO AVG <= 2.7 mg/L May, Jun, Jul, Aug, Sep, Oct
002Nitrogen, ammonia total [as N]MO AVG report only Jan, Feb, Mar, Apr, Nov, Dec
002Nitrogen, ammonia total [as N]DAILY MX <= 4.1 mg/L May, Jun, Jul, Aug, Sep, Oct
002Nitrogen, ammonia total [as N]DAILY MX report only Jan, Feb, Mar, Apr, Nov, Dec
002Nitrogen, ammonia total [as N]MO AVG <= 16.5 kg/d May, Jun, Jul, Aug, Sep, Oct
002Nitrogen, ammonia total [as N]DAILY MX <= 25 kg/d May, Jun, Jul, Aug, Sep, Oct
002Iron, total recoverableMO AVG report only all year
002Iron, total recoverableDAILY MX report only all year
002Zinc, total recoverableMO AVG report only all year
002Zinc, total recoverableDAILY MX report only 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
002Solids, total dissolved- 180 deg. CMO AVG report only all year
002Solids, total dissolved- 180 deg. CDAILY MX report only all year
003pHDAILY MN >= 6.5 SU all year
003pHDAILY MX <= 9 SU all year
003Solids, total suspendedMO AVG report only all year
003Solids, total suspendedDAILY MX report only all year
003Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
003Iron, total recoverableMO AVG report only all year
003Iron, total recoverableDAILY MX report only all year
003Selenium, total recoverableMO AVG report only all year
003Selenium, total recoverableDAILY MX report only all year
003Lead, total recoverableMO AVG report only all year
003Lead, total recoverableDAILY MX report only all year
003Oxidants, total residualDAILY MX <= .0024 mg/L Mar, Jun, Aug, Dec
003Oxidants, total residualDAILY MX <= .044 kg/d Mar, Jun, Aug, Dec
003Flow, in conduit or thru treatment plantMO AVG report only all year
003Flow, in conduit or thru treatment plantDAILY MX report only all year
003Mercury, total low levelMO AVG report only Mar, Jun, Aug, Dec
003Mercury, total low levelDAILY MX report only Mar, Jun, Aug, Dec
003Solids, total dissolved- 180 deg. CMO AVG report only all year
003Solids, total dissolved- 180 deg. CDAILY MX report only all year
004pHDAILY MN >= 6.5 SU all year
004pHDAILY MX <= 9 SU all year
004Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
004Fluoride, total [as F]MO AVG report only all year
004Fluoride, total [as F]DAILY MX report only all year
004Toxicity, choice of speciesMO AVG report only Mar, Jun, Aug, Dec
004Toxicity, choice of speciesDAILY MX report only Mar, Jun, Aug, Dec
004Chronic toxicity, daphnia magnia 21 dyMO AVG report only Mar, Jun, Aug, Dec
004Chronic toxicity, daphnia magnia 21 dyDAILY MX report only Mar, Jun, Aug, Dec
004Oxidants, total residualDAILY MX <= .0024 mg/L all year
004Oxidants, total residualDAILY MX <= .027 kg/d 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
004Solids, total dissolved- 180 deg. CMO AVG <= 2126 mg/L all year
004Solids, total dissolved- 180 deg. CMO AVG <= 39182 kg/d all year
005pHDAILY MN report only all year
005pHDAILY MX report only all year
005Solids, total suspendedMO AVG <= 977 kg/d all year
005Solids, total suspendedDAILY MX <= 1950 kg/d all year
005Oil and grease, hexane extr methodDAILY MX <= 227 kg/d all year
005Lead, total [as Pb]MO AVG <= 2.55 kg/d all year
005Lead, total [as Pb]DAILY MX <= 4.9 kg/d all year
005Zinc, total [as Zn]MO AVG <= 2.69 kg/d all year
005Zinc, total [as Zn]DAILY MX <= 6.74 kg/d 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
006pHDAILY MN >= 6.5 SU Mar, Jun, Aug, Dec
006pHDAILY MX <= 9 SU Mar, Jun, Aug, Dec
006Solids, total suspendedMO AVG report only all year
006Solids, total suspendedDAILY MX report only all year
006Zinc, total recoverableMO AVG report only all year
006Zinc, total recoverableDAILY MX report only all year
008Zinc, total recoverableMO AVG report only all year
008Zinc, total recoverableDAILY MX report only all year
008Copper, total recoverableMO AVG report only all year
008Copper, total recoverableDAILY MX report only all year
009Oxygen demand, chem. [low level] [COD]MO AVG report only all year
009Oxygen demand, chem. [low level] [COD]DAILY MX report only all year
009pHDAILY MN >= 6.5 SU all year
009pHDAILY MX <= 9 SU all year
009Solids, total suspendedMO AVG report only all year
009Solids, total suspendedDAILY MX report only all year
009Chromium, hexavalent dissolved [as Cr]MO AVG report only all year
009Chromium, hexavalent dissolved [as Cr]DAILY MX report only 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
011pHDAILY MN >= 6.5 SU all year
011pHDAILY MX <= 9 SU all year
011Solids, total suspendedMO AVG report only all year
011Solids, total suspendedDAILY MX report only all year
011Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
011Selenium, total recoverableMO AVG report only all year
011Selenium, total recoverableDAILY MX report only all year
011Oxidants, total residualDAILY MX <= .0048 mg/L all year
011Oxidants, total residualDAILY MX <= .19 kg/d 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
011Mercury, total low levelMO AVG report only all year
011Mercury, total low levelDAILY MX report only all year
011Toxicity [acute], Ceriodaphnia dubiaMO AVG report only Aug
011Toxicity [acute], Ceriodaphnia dubiaDAILY MX report only Aug
011Toxicity [acute], Pimephales promelas [Fathead Minnow]MO AVG report only Aug
011Toxicity [acute], Pimephales promelas [Fathead Minnow]DAILY MX report only Aug
015pHDAILY MN >= 6.5 SU all year
015pHDAILY MX <= 9 SU all year
015Solids, total suspendedMO AVG report only all year
015Solids, total suspendedDAILY MX report only all year
015Oil and grease, hexane extr methodDAILY MX <= 10 mg/L all year
015Fluoride, total [as F]MO AVG report only all year
015Fluoride, total [as F]DAILY MX report only all year
015Lead, total recoverableMO AVG report only all year
015Lead, total recoverableDAILY MX report only all year
015Oxidants, total residualDAILY MX <= .0024 mg/L Mar, Jun, Aug, Dec
015Oxidants, total residualDAILY MX <= .016 kg/d Mar, Jun, Aug, Dec
015Flow, in conduit or thru treatment plantMO AVG report only all year
015Flow, in conduit or thru treatment plantDAILY MX report only all year
015Solids, total dissolved- 180 deg. CMO AVG report only all year
015Solids, total dissolved- 180 deg. CDAILY MX report only all year
613pHDAILY MN report only all year
613pHDAILY MX report only all year
613Solids, total suspendedMO AVG report only all year
613Solids, total suspendedDAILY MX report only all year
613Oil and grease, hexane extr methodMO AVG report only all year
613Oil and grease, hexane extr methodDAILY MX report only all year
613Nitrogen, ammonia total [as N]MO AVG <= 205 kg/d all year
613Nitrogen, ammonia total [as N]DAILY MX <= 410 kg/d all year
613Cyanide, total [as CN]MO AVG <= 5.7 kg/d all year
613Cyanide, total [as CN]DAILY MX <= 11.4 kg/d all year
613Lead, total [as Pb]MO AVG report only all year
613Lead, total [as Pb]DAILY MX report only all year
613Zinc, total [as Zn]MO AVG report only all year
613Zinc, total [as Zn]DAILY MX report only all year
613Phenolics, total recoverableMO AVG <= .9 kg/d all year
613Phenolics, total recoverableDAILY MX <= 1.8 kg/d all year
613Flow, in conduit or thru treatment plantMO AVG report only all year
613Flow, in conduit or thru treatment plantDAILY MX report only all year
614pHDAILY MN report only all year
614pHDAILY MX report only all year
614Solids, total suspendedMO AVG report only all year
614Solids, total suspendedDAILY MX report only all year
614Oil and grease, hexane extr methodMO AVG report only all year
614Oil and grease, hexane extr methodDAILY MX report only all year
614Lead, total [as Pb]MO AVG report only all year
614Lead, total [as Pb]DAILY MX report only all year
614Zinc, total [as Zn]MO AVG report only all year
614Zinc, total [as Zn]DAILY MX report only all year
614Flow, in conduit or thru treatment plantMO AVG report only all year
614Flow, in conduit or thru treatment plantDAILY MX report only all year
631pHDAILY MN report only all year
631pHDAILY MX report only all year
631Solids, total suspendedMO AVG <= 522 kg/d all year
631Solids, total suspendedDAILY MX <= 1245 kg/d all year
631Lead, total [as Pb]MO AVG <= 1.74 kg/d all year
631Lead, total [as Pb]DAILY MX <= 7.48 kg/d all year
631Zinc, total [as Zn]MO AVG <= 3.5 kg/d all year
631Zinc, total [as Zn]DAILY MX <= 8 kg/d all year
631Flow, in conduit or thru treatment plantMO AVG report only all year
631Flow, in conduit or thru treatment plantDAILY MX report only all year
641pHDAILY MN report only all year
641pHDAILY MX report only all year
641Solids, total suspendedMO AVG <= 850 kg/d all year
641Solids, total suspendedDAILY MX <= 1661 kg/d all year
641Oil and grease, hexane extr methodMO AVG <= 306 kg/d all year
641Oil and grease, hexane extr methodDAILY MX <= 856 kg/d all year
641Zinc, total [as Zn]MO AVG <= 1.87 kg/d all year
641Zinc, total [as Zn]DAILY MX <= 3.9 kg/d all year
641Flow, in conduit or thru treatment plantMO AVG report only all year
641Flow, in conduit or thru treatment plantDAILY MX report only all year
642pHDAILY MN report only all year
642pHDAILY MX report only all year
642Solids, total suspendedMO AVG <= 31 mg/L all year
642Solids, total suspendedDAILY MX <= 60 mg/L all year
642Oil and grease, hexane extr methodMO AVG <= 26 mg/L all year
642Oil and grease, hexane extr methodDAILY MX <= 52 mg/L all year
642Zinc, total [as Zn]MO AVG <= 1480 ug/L all year
642Zinc, total [as Zn]DAILY MX <= 2610 ug/L all year
642Flow, in conduit or thru treatment plantMO AVG report only all year
642Flow, in conduit or thru treatment plantDAILY MX <= .36 MGD all year
642Organics, total toxic [TTO]DAILY MX <= 1704 ug/L Sep
800Flow, in conduit or thru treatment plantMO AVG report only all year
800Flow, in conduit or thru treatment plantDAILY MX report only all year
801%Effect Static Renewal 48Hr Acute Ceriodaphnia dubiaMO AVG report only Aug
801%Effect Static Renewal 48Hr Acute Ceriodaphnia dubiaDAILY MX report only Aug
801%Effect Static Renewal 96Hr Acute Pimephales promelasMO AVG report only Aug
801%Effect Static Renewal 96Hr Acute Pimephales promelasDAILY MX report only Aug
803pHDAILY MN report only all year
803pHDAILY MX report only all year
803Solids, total suspendedMO AVG report only all year
803Solids, total suspendedDAILY MX report only all year
803Oil and grease [soxhlet extr.] tot.MO AVG report only all year
803Oil and grease [soxhlet extr.] tot.DAILY MX report only all year
803Zinc, total recoverableMO AVG report only all year
803Zinc, total recoverableDAILY MX report only all year
803Flow, in conduit or thru treatment plantMO AVG report only all year
803Flow, in conduit or thru treatment plantDAILY MX report only all year
803Solids, total dissolved- 180 deg. CMO AVG report only all year
803Solids, total dissolved- 180 deg. CDAILY MX report only all year
804Chronic toxicity, daphnia magnia 21 dyMO AVG report only Mar, Jun, Aug, Dec
804Chronic toxicity, daphnia magnia 21 dyDAILY MX report only Mar, Jun, Aug, Dec
804%Effect Static Renewal 48Hr Acute D. magnaMO AVG report only Mar, Jun, Aug, Dec
804%Effect Static Renewal 48Hr Acute D. magnaDAILY MX report only Mar, Jun, Aug, Dec

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