Olney, City of — NPDES permit IL0048755: limits, due date and EPA's record

Sewage treatment plant, major discharger, Olney, Illinois. NPDES permit IL0048755 expired May 31, 2024; its limits still apply. Last 12 months: over a limit 8 times (last April 2026), 1 of 37 reports late. Source: EPA ECHO, Oct 22, 2026.

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

Period ending	Parameter	Reported	Limit	Over by
October 2025	Nitrogen, ammonia total [as N], daily maximum	15.3 mg/L	≤ 3 mg/L	410%
October 2025	Nitrogen, ammonia total [as N], monthly average	3.141 mg/L	≤ 1.5 mg/L	109%
January 2026	Zinc, total [as Zn], monthly average	.043 mg/L	≤ .038 mg/L	13%
February 2026	Nitrogen, ammonia total [as N], monthly average	5.185 mg/L	≤ 4 mg/L	30%
March 2026	Nitrogen, ammonia total [as N], monthly average	3.827 mg/L	≤ 2.6 mg/L	47%
April 2026	Nitrogen, ammonia total [as N], daily maximum	5.17 mg/L	≤ 3 mg/L	72%
April 2026	Nitrogen, ammonia total [as N], monthly average	1.867 mg/L	≤ 1.5 mg/L	24%
April 2026	Zinc, total [as Zn], monthly average	.041 mg/L	≤ .038 mg/L	8%

Limits in force (194)

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	≤ 550 lb/d	all year	001
Solids, total suspended	daily maximum	≤ 1101 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]	daily maximum	report only (mg/L)	all year	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	May	001
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Feb	001
Nitrogen, ammonia total [as N]	monthly average	≤ 2.6 mg/L	Mar	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Aug	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Jul	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Jun	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Sep	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Apr	001
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Nov	001
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Oct	001
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Jan	001
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Dec	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	May	001
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Feb	001
Nitrogen, ammonia total [as N]	monthly average	≤ 119 lb/d	Mar	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Aug	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Jul	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Jun	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Sep	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Apr	001
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Nov	001
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Oct	001
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Jan	001
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Dec	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	May	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Feb	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Mar	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Aug	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Jul	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Jun	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Sep	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Apr	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Nov	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Oct	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Jan	001
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Dec	001
Nitrogen, ammonia total [as N]	weekly average	≤ 6.5 mg/L	Mar	001
Nitrogen, ammonia total [as N]	weekly average	≤ 298 lb/d	Mar	001
Phosphorus, total [as P]	monthly average	≤ 1 mg/L	all year	001
Phosphorus, total [as P]	monthly average	≤ 46 lb/d	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
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
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]	monthly average	≤ .038 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
Zinc, total [as Zn]	monthly average	≤ 1.7 lb/d	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	May–Oct	001
Chlorine, total residual	daily maximum	≤ .05 mg/L	Jan, Feb, Mar, Apr, Nov, Dec	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	report only (#/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	≤ 459 lb/d	all year	001
BOD, carbonaceous [5 day, 20 C]	daily maximum	≤ 917 lb/d	all year	001
Oxygen, dissolved [DO]	monthly average minimum	≥ 5.5 mg/L	Jan, Feb, Aug, Sep, Oct, Nov, Dec	002
Oxygen, dissolved [DO]	minimum weekly average	≥ 6 mg/L	Mar–Jul	002
Oxygen, dissolved [DO]	minimum weekly average	≥ 4 mg/L	Jan, Feb, Aug, Sep, Oct, Nov, Dec	002
Oxygen, dissolved [DO]	daily minimum	≥ 5 mg/L	Mar–Jul	002
Oxygen, dissolved [DO]	daily minimum	≥ 3.5 mg/L	Jan, Feb, Aug, Sep, Oct, Nov, Dec	002
pH	minimum	≥ 6 SU	all year	002
pH	maximum	≤ 9 SU	all year	002
Solids, total suspended	monthly average	≤ 12 mg/L	all year	002
Solids, total suspended	daily maximum	≤ 24 mg/L	all year	002
Solids, total suspended	monthly average	≤ 550 lb/d	all year	002
Solids, total suspended	daily maximum	≤ 1101 lb/d	all year	002
Nitrogen, total [as N]	daily maximum	report only (mg/L)	all year	002
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Jan	002
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Feb	002
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Nov	002
Nitrogen, ammonia total [as N]	monthly average	≤ 4 mg/L	Dec	002
Nitrogen, ammonia total [as N]	monthly average	≤ 2.6 mg/L	Mar	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Apr	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	May	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Jun	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Jul	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Aug	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Sep	002
Nitrogen, ammonia total [as N]	monthly average	≤ 1.5 mg/L	Oct	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Jan	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Feb	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Nov	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Dec	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 8 mg/L	Mar	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Apr	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	May	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Jun	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Jul	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Aug	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Sep	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 3 mg/L	Oct	002
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Jan	002
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Feb	002
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Nov	002
Nitrogen, ammonia total [as N]	monthly average	≤ 183 lb/d	Dec	002
Nitrogen, ammonia total [as N]	monthly average	≤ 119 lb/d	Mar	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Apr	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	May	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Jun	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Jul	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Aug	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Sep	002
Nitrogen, ammonia total [as N]	monthly average	≤ 69 lb/d	Oct	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Jan	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Feb	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Nov	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Dec	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 367 lb/d	Mar	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Apr	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	May	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Jun	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Jul	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Aug	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Sep	002
Nitrogen, ammonia total [as N]	daily maximum	≤ 138 lb/d	Oct	002
Nitrogen, ammonia total [as N]	weekly average	≤ 6.5 mg/L	Mar	002
Nitrogen, ammonia total [as N]	weekly average	≤ 298 lb/d	Mar	002
Phosphorus, total [as P]	monthly average	≤ 1 mg/L	all year	002
Phosphorus, total [as P]	monthly average	≤ 46 lb/d	all year	002
Zinc, total [as Zn]	monthly average	≤ .038 mg/L	all year	002
Zinc, total [as Zn]	monthly average	≤ 1.7 lb/d	all year	002
Flow, in conduit or thru treatment plant	monthly average	report only (MGD)	all year	002
Flow, in conduit or thru treatment plant	daily maximum	report only (MGD)	all year	002
Chlorine, total residual	daily maximum	≤ .05 mg/L	May–Oct	002
Chlorine, total residual	daily maximum	≤ .05 mg/L	Jan, Feb, Mar, Apr, Nov, Dec	002
Coliform, fecal general	daily maximum	report only (#/100mL)	May–Oct	002
BOD, carbonaceous [5 day, 20 C]	monthly average	≤ 10 mg/L	all year	002
BOD, carbonaceous [5 day, 20 C]	daily maximum	≤ 20 mg/L	all year	002
BOD, carbonaceous [5 day, 20 C]	monthly average	≤ 459 lb/d	all year	002
BOD, carbonaceous [5 day, 20 C]	daily maximum	≤ 917 lb/d	all year	002
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

How strict are these limits?

Your permit document is the final word. As JSON: /api/v1/permits/IL0048755 · MCP: https://passage-data.com/mcp