Mattoon, City of — NPDES permit IL0029831: limits, due date and EPA's record

Sewage treatment plant, major discharger, Mattoon, Illinois. NPDES permit IL0029831 expired Feb 28, 2025; its limits still apply. Last 12 months: over a limit 4 times (last March 2026). Source: EPA ECHO, Oct 22, 2026.

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

Period ending	Outfall	Parameter	Reported	Limit	Over by
February 2026	001	Solids, total suspended, monthly average	13.5 mg/L	≤ 12 mg/L	13%
March 2026	001	Solids, total suspended, daily maximum	30 mg/L	≤ 24 mg/L	25%
March 2026	001	Solids, total suspended, monthly average	12.5 mg/L	≤ 12 mg/L	4%
March 2026	002	Coliform, fecal general, daily maximum	2630 #/100mL	≤ 400 #/100mL	558%

Limits in force (188)

Parameter	Statistic	Limit	Months	Outfall
Oxygen, dissolved [DO]	monthly average minimum	≥ 5.5 mg/L	Jan, Feb, Aug, Sep, Oct, Nov, Dec	001
Oxygen, dissolved [DO]	minimum weekly average	≥ 6 mg/L	Mar–Jul	001
Oxygen, dissolved [DO]	minimum weekly average	≥ 4 mg/L	Jan, Feb, Aug, Sep, Oct, Nov, Dec	001
Oxygen, dissolved [DO]	daily minimum	≥ 5 mg/L	Mar–Jul	001
Oxygen, dissolved [DO]	daily minimum	≥ 3.5 mg/L	Jan, Feb, Aug, Sep, Oct, Nov, Dec	001
pH	minimum	≥ 6 SU	all year	001
pH	maximum	≤ 9 SU	all year	001
Solids, total suspended	monthly average	≤ 12 mg/L	all year	001
Solids, total suspended	daily maximum	≤ 24 mg/L	all year	001
Solids, total suspended	monthly average	≤ 1401 lb/d	all year	001
Solids, total suspended	daily maximum	≤ 2802 lb/d	all year	001
Oil & Grease	daily maximum	report only (mg/L)	all year	001
Oil & Grease	daily maximum	report only (mg/L)	all year	001
Nitrogen, total [as N]	monthly average	report only (mg/L)	all year	001
Nitrogen, total [as N]	daily maximum	report only (mg/L)	all year	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	May	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Feb	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Mar	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Jul	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Sep	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Aug	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Jun	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Apr	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Jan	001
Nitrogen, ammonia total [as N]	monthly average	≤ .8 mg/L	Oct	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Dec	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3.4 mg/L	Nov	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	May	001
Nitrogen, ammonia total [as N]	monthly average	≤ 175 lb/d	Feb	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Mar	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Jul	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Sep	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Aug	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Jun	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Apr	001
Nitrogen, ammonia total [as N]	monthly average	≤ 175 lb/d	Jan	001
Nitrogen, ammonia total [as N]	monthly average	≤ 93 lb/d	Oct	001
Nitrogen, ammonia total [as N]	monthly average	≤ 175 lb/d	Dec	001
Nitrogen, ammonia total [as N]	monthly average	≤ 175 lb/d	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 350 lb/d	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 350 lb/d	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 350 lb/d	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 397 lb/d	Nov	001
Nitrogen, ammonia total [as N]	weekly average	≤ 2 mg/L	Jun–Aug	001
Nitrogen, ammonia total [as N]	weekly average	≤ 234 lb/d	Jun–Aug	001
Phosphorus, total [as P]	monthly average	report only (mg/L)	all year	001
Phosphorus, total [as P]	daily maximum	report only (mg/L)	all year	001
Cyanide, total [as CN]	daily maximum	report only (ug/L)	all year	001
Cyanide, total [as CN]	daily maximum	report only (ug/L)	all year	001
Cyanide, free [amenable to chlorination]	daily maximum	report only (ug/L)	all year	001
Cyanide, free [amenable to chlorination]	daily maximum	report only (ug/L)	all year	001
Fluoride, total [as F]	daily maximum	report only (mg/L)	all year	001
Fluoride, total [as F]	daily maximum	report only (mg/L)	all year	001
Arsenic, total [as As]	daily maximum	report only (mg/L)	all year	001
Arsenic, total [as As]	daily maximum	report only (mg/L)	all year	001
Barium, total [as Ba]	daily maximum	report only (mg/L)	all year	001
Barium, total [as Ba]	daily maximum	report only (mg/L)	all year	001
Beryllium, total [as Be]	daily maximum	report only (mg/L)	all year	001
Beryllium, total [as Be]	daily maximum	report only (mg/L)	all year	001
Cadmium, total [as Cd]	daily maximum	report only (mg/L)	all year	001
Cadmium, total [as Cd]	daily maximum	report only (mg/L)	all year	001
Chromium, hexavalent [as Cr]	daily maximum	report only (mg/L)	all year	001
Chromium, hexavalent [as Cr]	daily maximum	report only (mg/L)	all year	001
Chromium, total [as Cr]	daily maximum	report only (mg/L)	all year	001
Chromium, total [as Cr]	daily maximum	report only (mg/L)	all year	001
Copper, total [as Cu]	daily maximum	report only (mg/L)	all year	001
Copper, total [as Cu]	daily maximum	report only (mg/L)	all year	001
Iron, total [as Fe]	daily maximum	report only (mg/L)	all year	001
Iron, total [as Fe]	daily maximum	report only (mg/L)	all year	001
Iron, dissolved [as Fe]	daily maximum	report only (mg/L)	all year	001
Iron, dissolved [as Fe]	daily maximum	report only (mg/L)	all year	001
Lead, total [as Pb]	daily maximum	report only (mg/L)	all year	001
Lead, total [as Pb]	daily maximum	report only (mg/L)	all year	001
Manganese, total [as Mn]	daily maximum	report only (mg/L)	all year	001
Manganese, total [as Mn]	daily maximum	report only (mg/L)	all year	001
Thallium, total [as Tl]	daily maximum	report only (mg/L)	all year	001
Thallium, total [as Tl]	daily maximum	report only (mg/L)	all year	001
Nickel, total [as Ni]	daily maximum	report only (mg/L)	all year	001
Nickel, total [as Ni]	daily maximum	report only (mg/L)	all year	001
Silver, total [as Ag]	daily maximum	report only (mg/L)	all year	001
Silver, total [as Ag]	daily maximum	report only (mg/L)	all year	001
Zinc, total [as Zn]	daily maximum	report only (mg/L)	all year	001
Zinc, total [as Zn]	daily maximum	report only (mg/L)	all year	001
Antimony, total [as Sb]	daily maximum	report only (mg/L)	all year	001
Antimony, total [as Sb]	daily maximum	report only (mg/L)	all year	001
Selenium, total [as Se]	daily maximum	report only (mg/L)	all year	001
Selenium, total [as Se]	daily maximum	report only (mg/L)	all year	001
Phenolics, total recoverable	daily maximum	report only (mg/L)	all year	001
Phenolics, total recoverable	daily maximum	report only (mg/L)	all year	001
Flow, in conduit or thru treatment plant	monthly average	report only (MGD)	all year	001
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year	001
Chlorine, total residual	daily maximum	≤ .05 mg/L	all year	001
Mercury, total [as Hg]	daily maximum	report only (ng/L)	all year	001
Mercury, total [as Hg]	daily maximum	report only (ng/L)	all year	001
Coliform, fecal general	daily maximum	≤ 400 #/100mL	May–Oct	001
BOD, carbonaceous [5 day, 20 C]	monthly average	≤ 10 mg/L	all year	001
BOD, carbonaceous [5 day, 20 C]	daily maximum	≤ 20 mg/L	all year	001
BOD, carbonaceous [5 day, 20 C]	monthly average	≤ 1168 lb/d	all year	001
BOD, carbonaceous [5 day, 20 C]	daily maximum	≤ 2335 lb/d	all year	001
BOD, 5-day, 20 deg. C	monthly average	report only (mg/L)	all year	002
BOD, 5-day, 20 deg. C	daily maximum	report only (mg/L)	all year	002
pH	minimum	≥ 6 SU	all year	002
pH	maximum	≤ 9 SU	all year	002
Solids, total suspended	monthly average	report only (mg/L)	all year	002
Solids, total suspended	daily maximum	report only (mg/L)	all year	002
Nitrogen, ammonia total [as N]	monthly average	report only (mg/L)	all year	002
Nitrogen, ammonia total [as N]	daily maximum	report only (mg/L)	all year	002
Phosphorus, total [as P]	monthly average	report only (mg/L)	all year	002
Phosphorus, total [as P]	daily maximum	report only (mg/L)	all year	002
Chlorine, total residual	monthly average	≤ .75 mg/L	all year	002
Coliform, fecal general	daily maximum	≤ 400 #/100mL	all year	002
Flow, total	monthly total	report only (Mgal/mo)	all year	002
Overflows	monthly total	report only (#/mo)	all year	003
Overflows	monthly total	report only (#/mo)	all year	004
Overflows	monthly total	report only (#/mo)	all year	005
Overflows	monthly total	report only (#/mo)	all year	006
Overflows	monthly total	report only (#/mo)	all year	007
Overflows	monthly total	report only (#/mo)	all year	008
BOD, 5-day, 20 deg. C	monthly average	report only (mg/L)	all year	INF
Solids, total suspended	monthly average	report only (mg/L)	all year	INF
Flow, in conduit or thru treatment plant	monthly average	report only (MGD)	all year	INF
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year	INF
Oil & Grease	daily maximum	report only (mg/L)	all year	INFL
Oil & Grease	daily maximum	report only (mg/L)	all year	INFL
Cyanide, total [as CN]	daily maximum	report only (ug/L)	all year	INFL
Cyanide, total [as CN]	daily maximum	report only (ug/L)	all year	INFL
Cyanide, free [amenable to chlorination]	daily maximum	report only (ug/L)	all year	INFL
Cyanide, free [amenable to chlorination]	daily maximum	report only (ug/L)	all year	INFL
Fluoride, total [as F]	daily maximum	report only (mg/L)	all year	INFL
Fluoride, total [as F]	daily maximum	report only (mg/L)	all year	INFL
Arsenic, total [as As]	daily maximum	report only (mg/L)	all year	INFL
Arsenic, total [as As]	daily maximum	report only (mg/L)	all year	INFL
Barium, total [as Ba]	daily maximum	report only (mg/L)	all year	INFL
Barium, total [as Ba]	daily maximum	report only (mg/L)	all year	INFL
Beryllium, total [as Be]	daily maximum	report only (mg/L)	all year	INFL
Beryllium, total [as Be]	daily maximum	report only (mg/L)	all year	INFL
Cadmium, total [as Cd]	daily maximum	report only (mg/L)	all year	INFL
Cadmium, total [as Cd]	daily maximum	report only (mg/L)	all year	INFL
Chromium, hexavalent [as Cr]	daily maximum	report only (mg/L)	all year	INFL
Chromium, hexavalent [as Cr]	daily maximum	report only (mg/L)	all year	INFL
Chromium, total [as Cr]	daily maximum	report only (mg/L)	all year	INFL
Chromium, total [as Cr]	daily maximum	report only (mg/L)	all year	INFL
Copper, total [as Cu]	daily maximum	report only (mg/L)	all year	INFL
Copper, total [as Cu]	daily maximum	report only (mg/L)	all year	INFL
Iron, total [as Fe]	daily maximum	report only (mg/L)	all year	INFL
Iron, total [as Fe]	daily maximum	report only (mg/L)	all year	INFL
Iron, dissolved [as Fe]	daily maximum	report only (mg/L)	all year	INFL
Iron, dissolved [as Fe]	daily maximum	report only (mg/L)	all year	INFL
Lead, total [as Pb]	daily maximum	report only (mg/L)	all year	INFL
Lead, total [as Pb]	daily maximum	report only (mg/L)	all year	INFL
Manganese, total [as Mn]	daily maximum	report only (mg/L)	all year	INFL
Manganese, total [as Mn]	daily maximum	report only (mg/L)	all year	INFL
Thallium, total [as Tl]	daily maximum	report only (mg/L)	all year	INFL
Thallium, total [as Tl]	daily maximum	report only (mg/L)	all year	INFL
Nickel, total [as Ni]	daily maximum	report only (mg/L)	all year	INFL
Nickel, total [as Ni]	daily maximum	report only (mg/L)	all year	INFL
Silver, total [as Ag]	daily maximum	report only (mg/L)	all year	INFL
Silver, total [as Ag]	daily maximum	report only (mg/L)	all year	INFL
Zinc, total [as Zn]	daily maximum	report only (mg/L)	all year	INFL
Zinc, total [as Zn]	daily maximum	report only (mg/L)	all year	INFL
Antimony, total [as Sb]	daily maximum	report only (mg/L)	all year	INFL
Antimony, total [as Sb]	daily maximum	report only (mg/L)	all year	INFL
Selenium, total [as Se]	daily maximum	report only (mg/L)	all year	INFL
Selenium, total [as Se]	daily maximum	report only (mg/L)	all year	INFL
Phenolics, total recoverable	daily maximum	report only (mg/L)	all year	INFL
Phenolics, total recoverable	daily maximum	report only (mg/L)	all year	INFL
Mercury, total [as Hg]	daily maximum	report only (ng/L)	all year	INFL
Mercury, total [as Hg]	daily maximum	report only (ng/L)	all year	INFL

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/IL0029831 · MCP: https://passage-data.com/mcp