Muscatine Power and Water — NPDES permit IA0001082: limits, due date and EPA's record

Electric And Other Services Combined, major discharger, Muscatine, Iowa. NPDES permit IA0001082, in force until Aug 31, 2030. Last 12 months: over a limit once (last December 2025), 64 required values missing. Source: EPA ECHO, Oct 22, 2026.

Last 12 months (Oct 1, 2025 – Sep 30, 2026)

Period ending	Parameter	Reported	Limit
December 2025	pH, daily maximum	9.02	≤ 9 SU

Limits in force (178)

Parameter	Statistic	Limit	Months	Outfall
Temperature, water deg. fahrenheit	30-day average	≤ 117.5 deg F	Nov	001
Temperature, water deg. fahrenheit	30-day average	≤ 136 deg F	Jul	001
Temperature, water deg. fahrenheit	30-day average	≤ 166.5 deg F	May	001
Temperature, water deg. fahrenheit	30-day average	≤ 132.8 deg F	Aug	001
Temperature, water deg. fahrenheit	30-day average	≤ 94.3 deg F	Feb	001
Temperature, water deg. fahrenheit	30-day average	≤ 128.2 deg F	Mar	001
Temperature, water deg. fahrenheit	30-day average	≤ 179.8 deg F	Apr	001
Temperature, water deg. fahrenheit	30-day average	≤ 157.9 deg F	Jun	001
Temperature, water deg. fahrenheit	30-day average	≤ 122.8 deg F	Oct	001
Temperature, water deg. fahrenheit	30-day average	≤ 90.7 deg F	Dec	001
Temperature, water deg. fahrenheit	30-day average	≤ 86.9 deg F	Jan	001
Temperature, water deg. fahrenheit	30-day average	≤ 134.2 deg F	Sep	001
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Nov	001
Temperature, water deg. fahrenheit	daily maximum	≤ 136 deg F	Jul	001
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	May	001
Temperature, water deg. fahrenheit	daily maximum	≤ 132.8 deg F	Aug	001
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Feb	001
Temperature, water deg. fahrenheit	daily maximum	≤ 186.6 deg F	Mar	001
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Apr	001
Temperature, water deg. fahrenheit	daily maximum	≤ 195.9 deg F	Jun	001
Temperature, water deg. fahrenheit	daily maximum	≤ 197.9 deg F	Oct	001
Temperature, water deg. fahrenheit	daily maximum	≤ 155.5 deg F	Dec	001
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Jan	001
Temperature, water deg. fahrenheit	daily maximum	≤ 169.4 deg F	Sep	001
Temperature, length of excursion	daily maximum	≤ 87.6 hr/12mo	all year	001
Flow, in conduit or thru treatment plant	daily maximum	≤ 25.9 MGD	all year	001
Chlorine, total residual	daily maximum	≤ .2 mg/L	all year	001
Chlorine, total residual	daily maximum	≤ 15 lb/d	all year	001
Chlorination duration	daily maximum	≤ 2 hr/d	all year	001
Temperature, water deg. fahrenheit	30-day average	≤ 134.2 deg F	Sep	002
Temperature, water deg. fahrenheit	30-day average	≤ 117.5 deg F	Nov	002
Temperature, water deg. fahrenheit	30-day average	≤ 132.8 deg F	Aug	002
Temperature, water deg. fahrenheit	30-day average	≤ 136 deg F	Jul	002
Temperature, water deg. fahrenheit	30-day average	≤ 179.8 deg F	Apr	002
Temperature, water deg. fahrenheit	30-day average	≤ 128.2 deg F	Mar	002
Temperature, water deg. fahrenheit	30-day average	≤ 90.7 deg F	Dec	002
Temperature, water deg. fahrenheit	30-day average	≤ 94.3 deg F	Feb	002
Temperature, water deg. fahrenheit	30-day average	≤ 166.5 deg F	May	002
Temperature, water deg. fahrenheit	30-day average	≤ 122.8 deg F	Oct	002
Temperature, water deg. fahrenheit	30-day average	≤ 157.9 deg F	Jun	002
Temperature, water deg. fahrenheit	30-day average	≤ 86.9 deg F	Jan	002
Temperature, water deg. fahrenheit	daily maximum	≤ 169.4 deg F	Sep	002
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Nov	002
Temperature, water deg. fahrenheit	daily maximum	≤ 132.8 deg F	Aug	002
Temperature, water deg. fahrenheit	daily maximum	≤ 136 deg F	Jul	002
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Apr	002
Temperature, water deg. fahrenheit	daily maximum	≤ 186.6 deg F	Mar	002
Temperature, water deg. fahrenheit	daily maximum	≤ 155.5 deg F	Dec	002
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Feb	002
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	May	002
Temperature, water deg. fahrenheit	daily maximum	≤ 197.9 deg F	Oct	002
Temperature, water deg. fahrenheit	daily maximum	≤ 195.9 deg F	Jun	002
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Jan	002
pH	daily minimum	≥ 6 SU	all year	002
pH	daily maximum	≤ 9 SU	all year	002
Solids, total suspended	30-day average	≤ 30 mg/L	all year	002
Solids, total suspended	daily maximum	≤ 100 mg/L	all year	002
Oil & Grease	30-day average	≤ 15 mg/L	all year	002
Oil & Grease	daily maximum	≤ 20 mg/L	all year	002
Temperature, length of excursion	daily maximum	≤ 87.6 hr/12mo	all year	002
Chlorine, total residual	30-day average	≤ .995 mg/L	all year	002
Chlorine, total residual	daily maximum	≤ .995 mg/L	all year	002
Chlorine, total residual	30-day average	≤ 13.292 lb/d	all year	002
Chlorine, total residual	daily maximum	≤ 13.292 lb/d	all year	002
Temperature, water deg. fahrenheit	30-day average	≤ 117.5 deg F	Nov	003
Temperature, water deg. fahrenheit	30-day average	≤ 157.9 deg F	Jun	003
Temperature, water deg. fahrenheit	30-day average	≤ 90.7 deg F	Dec	003
Temperature, water deg. fahrenheit	30-day average	≤ 132.8 deg F	Aug	003
Temperature, water deg. fahrenheit	30-day average	≤ 86.9 deg F	Jan	003
Temperature, water deg. fahrenheit	30-day average	≤ 179.8 deg F	Apr	003
Temperature, water deg. fahrenheit	30-day average	≤ 134.2 deg F	Sep	003
Temperature, water deg. fahrenheit	30-day average	≤ 136 deg F	Jul	003
Temperature, water deg. fahrenheit	30-day average	≤ 166.5 deg F	May	003
Temperature, water deg. fahrenheit	30-day average	≤ 94.3 deg F	Feb	003
Temperature, water deg. fahrenheit	30-day average	≤ 122.8 deg F	Oct	003
Temperature, water deg. fahrenheit	30-day average	≤ 128.2 deg F	Mar	003
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Nov	003
Temperature, water deg. fahrenheit	daily maximum	≤ 195.9 deg F	Jun	003
Temperature, water deg. fahrenheit	daily maximum	≤ 155.5 deg F	Dec	003
Temperature, water deg. fahrenheit	daily maximum	≤ 132.8 deg F	Aug	003
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Jan	003
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Apr	003
Temperature, water deg. fahrenheit	daily maximum	≤ 169.4 deg F	Sep	003
Temperature, water deg. fahrenheit	daily maximum	≤ 136 deg F	Jul	003
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	May	003
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Feb	003
Temperature, water deg. fahrenheit	daily maximum	≤ 197.9 deg F	Oct	003
Temperature, water deg. fahrenheit	daily maximum	≤ 186.6 deg F	Mar	003
Temperature, length of excursion	daily maximum	≤ 87.6 hr/12mo	all year	003
Flow, in conduit or thru treatment plant	daily maximum	≤ 13.1 MGD	all year	003
Chlorine, total residual	daily maximum	≤ .2 mg/L	all year	003
Chlorine, total residual	daily maximum	≤ 7.6 lb/d	all year	003
Chlorination duration	daily maximum	≤ 2 hr/d	all year	003
Temperature, water deg. fahrenheit	30-day average	≤ 128.2 deg F	Mar	004
Temperature, water deg. fahrenheit	30-day average	≤ 90.7 deg F	Dec	004
Temperature, water deg. fahrenheit	30-day average	≤ 94.3 deg F	Feb	004
Temperature, water deg. fahrenheit	30-day average	≤ 132.8 deg F	Aug	004
Temperature, water deg. fahrenheit	30-day average	≤ 166.5 deg F	May	004
Temperature, water deg. fahrenheit	30-day average	≤ 86.9 deg F	Jan	004
Temperature, water deg. fahrenheit	30-day average	≤ 157.9 deg F	Jun	004
Temperature, water deg. fahrenheit	30-day average	≤ 117.5 deg F	Nov	004
Temperature, water deg. fahrenheit	30-day average	≤ 136 deg F	Jul	004
Temperature, water deg. fahrenheit	30-day average	≤ 179.8 deg F	Apr	004
Temperature, water deg. fahrenheit	30-day average	≤ 122.8 deg F	Oct	004
Temperature, water deg. fahrenheit	30-day average	≤ 134.2 deg F	Sep	004
Temperature, water deg. fahrenheit	daily maximum	≤ 186.6 deg F	Mar	004
Temperature, water deg. fahrenheit	daily maximum	≤ 155.5 deg F	Dec	004
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Feb	004
Temperature, water deg. fahrenheit	daily maximum	≤ 132.8 deg F	Aug	004
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	May	004
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Jan	004
Temperature, water deg. fahrenheit	daily maximum	≤ 195.9 deg F	Jun	004
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Nov	004
Temperature, water deg. fahrenheit	daily maximum	≤ 136 deg F	Jul	004
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Apr	004
Temperature, water deg. fahrenheit	daily maximum	≤ 197.9 deg F	Oct	004
Temperature, water deg. fahrenheit	daily maximum	≤ 169.4 deg F	Sep	004
pH	daily minimum	≥ 6 SU	all year	004
pH	daily maximum	≤ 9 SU	all year	004
Solids, total suspended	30-day average	≤ 30 mg/L	all year	004
Solids, total suspended	daily maximum	≤ 100 mg/L	all year	004
Oil & Grease	30-day average	≤ 15 mg/L	all year	004
Oil & Grease	daily maximum	≤ 20 mg/L	all year	004
Oil & Grease	30-day average	≤ 7.4 lb/d	all year	004
Oil & Grease	daily maximum	≤ 9.8 lb/d	all year	004
Temperature, length of excursion	daily maximum	≤ 87.6 hr/12mo	all year	004
Chlorine, total residual	30-day average	≤ .325 mg/L	all year	004
Chlorine, total residual	daily maximum	≤ .325 mg/L	all year	004
Chlorine, total residual	30-day average	≤ .535 lb/d	all year	004
Chlorine, total residual	daily maximum	≤ .535 lb/d	all year	004
Temperature, water deg. fahrenheit	30-day average	≤ 90.7 deg F	Dec	006
Temperature, water deg. fahrenheit	30-day average	≤ 128.2 deg F	Mar	006
Temperature, water deg. fahrenheit	30-day average	≤ 179.8 deg F	Apr	006
Temperature, water deg. fahrenheit	30-day average	≤ 86.9 deg F	Jan	006
Temperature, water deg. fahrenheit	30-day average	≤ 122.8 deg F	Oct	006
Temperature, water deg. fahrenheit	30-day average	≤ 94.3 deg F	Feb	006
Temperature, water deg. fahrenheit	30-day average	≤ 117.5 deg F	Nov	006
Temperature, water deg. fahrenheit	30-day average	≤ 157.9 deg F	Jun	006
Temperature, water deg. fahrenheit	30-day average	≤ 134.2 deg F	Sep	006
Temperature, water deg. fahrenheit	30-day average	≤ 132.8 deg F	Aug	006
Temperature, water deg. fahrenheit	30-day average	≤ 136 deg F	Jul	006
Temperature, water deg. fahrenheit	30-day average	≤ 166.5 deg F	May	006
Temperature, water deg. fahrenheit	daily maximum	≤ 155.5 deg F	Dec	006
Temperature, water deg. fahrenheit	daily maximum	≤ 186.6 deg F	Mar	006
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Apr	006
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Jan	006
Temperature, water deg. fahrenheit	daily maximum	≤ 197.9 deg F	Oct	006
Temperature, water deg. fahrenheit	daily maximum	≤ 144.9 deg F	Feb	006
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	Nov	006
Temperature, water deg. fahrenheit	daily maximum	≤ 195.9 deg F	Jun	006
Temperature, water deg. fahrenheit	daily maximum	≤ 169.4 deg F	Sep	006
Temperature, water deg. fahrenheit	daily maximum	≤ 132.8 deg F	Aug	006
Temperature, water deg. fahrenheit	daily maximum	≤ 136 deg F	Jul	006
Temperature, water deg. fahrenheit	daily maximum	≤ 212 deg F	May	006
Temperature, length of excursion	daily maximum	≤ 87.6 hr/12mo	all year	006
Chlorine, total residual	daily maximum	≤ .2 mg/L	all year	006
Chlorine, total residual	daily maximum	≤ 19 lb/d	all year	006
Chlorination duration	daily maximum	≤ 2 hr/d	all year	006
pH	daily minimum	≥ 6 SU	all year	106
pH	daily maximum	≤ 9 SU	all year	106
Solids, total suspended	30-day average	≤ 212 lb/d	all year	106
Solids, total suspended	daily maximum	≤ 717 lb/d	all year	106
Oil & Grease	30-day average	≤ 107 lb/d	all year	106
Oil & Grease	daily maximum	≤ 143 lb/d	all year	106
Copper, total [as Cu]	30-day average	≤ .7167 mg/L	all year	106
Copper, total [as Cu]	daily maximum	≤ .7167 mg/L	all year	106
Copper, total [as Cu]	30-day average	≤ 7.99 lb/d	all year	106
Copper, total [as Cu]	daily maximum	≤ 7.99 lb/d	all year	106
Toxicity [acute], Ceriodaphnia dubia	daily maximum	≤ 1 N=0;Y=1	all year	106
Toxicity [acute], Pimephales promelas [Fathead Minnow]	daily maximum	≤ 1 N=0;Y=1	all year	106
Mercury, total [as Hg]	30-day average	≤ .04389 mg/L	all year	106
Mercury, total [as Hg]	daily maximum	≤ .04389 mg/L	all year	106
Mercury, total [as Hg]	30-day average	≤ .4892 lb/d	all year	106
Mercury, total [as Hg]	daily maximum	≤ .4892 lb/d	all year	106
Copper, total [as Cu]	30-day average	≤ 1 mg/L	all year	117
Copper, total [as Cu]	daily maximum	≤ 1 mg/L	all year	117
Iron, total [as Fe]	30-day average	≤ 1 mg/L	all year	117
Iron, total [as Fe]	daily maximum	≤ 1 mg/L	all year	117

New limits from Jan 1, 2029

Parameter	New limit	New or tighter	Median, last 12 months	× new limit
Arsenic, total [as As], daily maximum	0.005 mg/L	new	—	—
Bromide [as Br], daily maximum	0.2 mg/L	new	—	—
Mercury, total [as Hg], 30-day average	0.00001 mg/L	new	—	—
Mercury, total [as Hg], daily maximum	0.000023 mg/L	new	—	—
Nitrite + Nitrate total [as N], 30-day average	1.2 mg/L	new	—	—
Nitrite + Nitrate total [as N], daily maximum	2 mg/L	new	—	—
Selenium, total [as Se], daily maximum	0.01 mg/L	new	—	—
Solids, total dissolved, 30-day average	149 mg/L	new	—	—
Solids, total dissolved, daily maximum	306 mg/L	new	—	—

How strict are these limits?

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