OGLESBY STP, CITY OF
NPDES ID: IL0024996
E — SNC: Effluent violation (monthly average limit)
The facility discharged more of a pollutant than its permit allows, based on a monthly average.
This quarter: 9 effluent violations.
Violations
May 31, 2026
Nitrogen, ammonia total [as N]
246% over limit
Discharged 8.66 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
42% over limit
Discharged 7.71799994 kg/d against a permitted limit of 5.44799995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
54% over limit
Discharged 18.15999985 kg/d against a permitted limit of 11.8039999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
256% over limit
Discharged 4.27 mg/L against a permitted limit of 1.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Oxygen, dissolved [DO]
3% over limit
Discharged 6.08 mg/L against a permitted limit of 6.25 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
256% over limit
Discharged 8.9 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
102% over limit
Discharged 23.7895998 kg/d against a permitted limit of 11.8039999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
162% over limit
Discharged 3.14 mg/L against a permitted limit of 1.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
83% over limit
Discharged 9.98799992 kg/d against a permitted limit of 5.44799995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
299% over limit
Discharged 21.74659982 kg/d against a permitted limit of 5.44799995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
5% over limit
Discharged 5.94 mg/L against a permitted limit of 6.25 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
346% over limit
Discharged 12.5 mg/L against a permitted limit of 2.8 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
179% over limit
Discharged 36.72859969 kg/d against a permitted limit of 13.16599989 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
694% over limit
Discharged 9.53 mg/L against a permitted limit of 1.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
67% over limit
Discharged 24.96999979 kg/d against a permitted limit of 14.98199987 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
478% over limit
Discharged 13.3 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
57% over limit
Discharged 16.34399986 kg/d against a permitted limit of 10.44199991 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
534% over limit
Discharged 20.3 mg/L against a permitted limit of 3.2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
41% over limit
Discharged 23.6079998 kg/d against a permitted limit of 16.79799986 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
350% over limit
Discharged 16.2 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
8% over limit
Discharged 43 mg/L against a permitted limit of 40 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
December 31, 2025
Solids, total suspended
16% over limit
Discharged 52 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
331% over limit
Discharged 15.5 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
69% over limit
Discharged 28.42039976 kg/d against a permitted limit of 16.79799986 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
16% over limit
Discharged 29 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
3% over limit
Discharged 41 mg/L against a permitted limit of 40 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
414% over limit
Discharged 18.5 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
93% over limit
Discharged 32.37019973 kg/d against a permitted limit of 16.79799986 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2025
Nitrogen, ammonia total [as N]
708% over limit
Discharged 20.2 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
505% over limit
Discharged 9.07 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 0 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Chlorine, total residual
23% over limit
Discharged 0.92 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
84% over limit
Discharged 21.70119982 kg/d against a permitted limit of 11.8039999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
41% over limit
Discharged 9.62479992 kg/d against a permitted limit of 6.80999994 kg/d (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, ammonia total [as N]
273% over limit
Discharged 5.6 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Chlorine, total residual
21% over limit
Discharged 0.91 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
252% over limit
Discharged 8.8 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
Nitrogen, ammonia total [as N]
97% over limit
Discharged 2.96 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
105% over limit
Discharged 5.12 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Chlorine, total residual
32% over limit
Discharged 0.99 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2025
Oxygen, dissolved [DO]
1% over limit
Discharged 6.17 mg/L against a permitted limit of 6.25 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Chlorine, total residual
32% over limit
Discharged 0.99 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
Chlorine, total residual
11% over limit
Discharged 0.83 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 0 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
39% over limit
Discharged 2.08 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
82% over limit
Discharged 4.55 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
May 31, 2025
Chlorine, total residual
15% over limit
Discharged 0.86 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
35% over limit
Discharged 2.03 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
72% over limit
Discharged 4.3 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2025
Nitrogen, ammonia total [as N]
368% over limit
Discharged 11.7 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
135% over limit
Discharged 16.02619987 kg/d against a permitted limit of 6.80999994 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
187% over limit
Discharged 33.91379972 kg/d against a permitted limit of 11.8039999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
257% over limit
Discharged 5.35 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
2% over limit
Discharged 6.14 mg/L against a permitted limit of 6.25 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
March 31, 2025
Nitrogen, ammonia total [as N]
191% over limit
Discharged 4.37 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
166% over limit
Discharged 7.44 mg/L against a permitted limit of 2.8 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
112% over limit
Discharged 27.96639977 kg/d against a permitted limit of 13.16599989 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
109% over limit
Discharged 14.21019988 kg/d against a permitted limit of 6.80999994 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
4% over limit
Discharged 6.01 mg/L against a permitted limit of 6.25 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
February 28, 2025
Nitrogen, ammonia total [as N]
173% over limit
Discharged 9.83 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2025
Nitrogen, ammonia total [as N]
397% over limit
Discharged 17.9 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
70% over limit
Discharged 28.60199976 kg/d against a permitted limit of 16.79799986 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2024
Nitrogen, ammonia total [as N]
303% over limit
Discharged 14.5 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
8% over limit
Discharged 18.15999985 kg/d against a permitted limit of 16.79799986 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2024
Nitrogen, ammonia total [as N]
70% over limit
Discharged 28.51119976 kg/d against a permitted limit of 16.79799986 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
372% over limit
Discharged 17 mg/L against a permitted limit of 3.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
16% over limit
Discharged 5.03 mg/L against a permitted limit of 6 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
October 31, 2024
Chlorine, total residual
32% over limit
Discharged 0.99 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
246% over limit
Discharged 5.19 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
206% over limit
Discharged 7.64 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 0 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Nitrogen, ammonia total [as N]
19% over limit
Discharged 1.79 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Chlorine, total residual
39% over limit
Discharged 1.04 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2024
Nitrogen, ammonia total [as N]
45% over limit
Discharged 2.17 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
34% over limit
Discharged 3.34 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 0 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
24% over limit
Discharged 4.58 mg/L against a permitted limit of 6 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
5% over limit
Discharged 4.28 mg/L against a permitted limit of 4.5 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Chlorine, total residual
31% over limit
Discharged 0.98 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2024
Coliform, fecal general
Limit violation
Discharged 0 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
21% over limit
Discharged 1.81 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
22% over limit
Discharged 4.88 mg/L against a permitted limit of 6.25 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
5% over limit
Discharged 2.63 mg/L against a permitted limit of 2.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
10% over limit
Discharged 4.51 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Chlorine, total residual
33% over limit
Discharged 1 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (24 days ago)