GREAT RIVER UTILITY OPERATING CO LLC, OAK PARK SUBDIVISION
NPDES ID: MS0032972
X — SNC: Effluent violation (non-monthly average limit)
The facility discharged more of a pollutant than its permit allows, measured over a period other than a monthly average.
This quarter: 6 effluent violations.
Violations
June 30, 2026
Nitrogen, ammonia total [as N]
1170% over limit
Discharged 25.4 mg/L against a permitted limit of 2 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
27% over limit
Discharged 19 mg/L against a permitted limit of 15 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
90% over limit
Discharged 19 mg/L against a permitted limit of 10 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
274% over limit
Discharged 5.09387996 kg/d against a permitted limit of 1.362 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
747% over limit
Discharged 25.4 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
149% over limit
Discharged 5.09387996 kg/d against a permitted limit of 2.043 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
890% over limit
Discharged 29.7 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
127% over limit
Discharged 34 mg/L against a permitted limit of 15 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1385% over limit
Discharged 29.7 mg/L against a permitted limit of 2 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
240% over limit
Discharged 34 mg/L against a permitted limit of 10 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
322% over limit
Discharged 5.74763995 kg/d against a permitted limit of 1.362 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
181% over limit
Discharged 5.74763995 kg/d against a permitted limit of 2.043 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Chlorine, total residual
163% over limit
Discharged 0.05 mg/L against a permitted limit of 0.019 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
Chlorine, total residual
245% over limit
Discharged 0.038 mg/L against a permitted limit of 0.011 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
927% over limit
Discharged 30.8 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
267% over limit
Discharged 4.99399996 kg/d against a permitted limit of 1.362 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
144% over limit
Discharged 4.99399996 kg/d against a permitted limit of 2.043 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1440% over limit
Discharged 30.8 mg/L against a permitted limit of 2 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Chlorine, total residual
163% over limit
Discharged 0.05 mg/L against a permitted limit of 0.019 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2025
Nitrogen, ammonia total [as N]
249% over limit
Discharged 7.12779994 kg/d against a permitted limit of 2.043 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
570% over limit
Discharged 20.1 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
423% over limit
Discharged 7.12779994 kg/d against a permitted limit of 1.362 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
Chlorine, total residual
11479% over limit
Discharged 2.2 mg/L against a permitted limit of 0.019 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Chlorine, total residual
1536% over limit
Discharged 0.18 mg/L against a permitted limit of 0.011 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
905% over limit
Discharged 20.1 mg/L against a permitted limit of 2 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
December 31, 2024
BOD, 5-day, 20 deg. C
247% over limit
Discharged 52 mg/L against a permitted limit of 15 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Chlorine, total residual
2082% over limit
Discharged 0.24 mg/L against a permitted limit of 0.011 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
793% over limit
Discharged 26.8 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
7% over limit
Discharged 32 mg/L against a permitted limit of 30 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
2157% over limit
Discharged 30.74487974 kg/d against a permitted limit of 1.362 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
773% over limit
Discharged 59.4739995 kg/d against a permitted limit of 6.81 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
420% over limit
Discharged 52 mg/L against a permitted limit of 10 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Solids, total suspended
80% over limit
Discharged 36.71497969 kg/d against a permitted limit of 20.43 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
482% over limit
Discharged 59.4739995 kg/d against a permitted limit of 10.215 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1240% over limit
Discharged 26.8 mg/L against a permitted limit of 2 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1405% over limit
Discharged 30.74487974 kg/d against a permitted limit of 2.043 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
20% over limit
Discharged 36.71497969 kg/d against a permitted limit of 30.645 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Chlorine, total residual
11479% over limit
Discharged 2.2 mg/L against a permitted limit of 0.019 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Nitrogen, ammonia total [as N]
17% over limit
Discharged 1.58899999 kg/d against a permitted limit of 1.362 kg/d (MX MO AV)
DMR, Limited - Numeric Violation
Chlorine, total residual
264% over limit
Discharged 0.04 mg/L against a permitted limit of 0.011 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
323% over limit
Discharged 12.7 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
220% over limit
Discharged 32 mg/L against a permitted limit of 10 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
113% over limit
Discharged 32 mg/L against a permitted limit of 15 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
535% over limit
Discharged 12.7 mg/L against a permitted limit of 2 mg/L (MX MO AV)
DMR, Limited - Numeric Violation
Chlorine, total residual
953% over limit
Discharged 0.2 mg/L against a permitted limit of 0.019 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 16, 2026 (19 minutes ago)