OTTER CREEK LAKE UTILITY DISTRICT STP
NPDES ID: IL0048593
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: 13 effluent violations.
Violations
June 30, 2026
Nitrogen, ammonia total [as N]
490% over limit
Discharged 17.7 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
33% over limit
Discharged 16 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
642% over limit
Discharged 8.9 mg/L against a permitted limit of 1.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
22% over limit
Discharged 13.80159988 kg/d against a permitted limit of 11.3499999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
67% over limit
Discharged 7.58179994 kg/d against a permitted limit of 4.53999996 kg/d (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2026
Nitrogen, ammonia total [as N]
420% over limit
Discharged 7.8 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
13% over limit
Discharged 5.2 mg/L against a permitted limit of 6 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Solids, total suspended
38% over limit
Discharged 33 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
463% over limit
Discharged 16.9 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
9% over limit
Discharged 6.44679995 kg/d against a permitted limit of 5.90199995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
8% over limit
Discharged 13 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
24% over limit
Discharged 14.07399988 kg/d against a permitted limit of 11.3499999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
30% over limit
Discharged 3.5 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
111% over limit
Discharged 13.9 mg/L against a permitted limit of 6.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, ammonia total [as N]
193% over limit
Discharged 8.8 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
53% over limit
Discharged 2.3 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
June 30, 2025
Nitrogen, ammonia total [as N]
7% over limit
Discharged 3.2 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
133% over limit
Discharged 7 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
47% over limit
Discharged 2.2 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2024
Nitrogen, ammonia total [as N]
437% over limit
Discharged 16.1 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
67% over limit
Discharged 2.5 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2024
Nitrogen, ammonia total [as N]
90% over limit
Discharged 8.62599993 kg/d against a permitted limit of 4.53999996 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
26% over limit
Discharged 14.25559988 kg/d against a permitted limit of 11.3499999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
437% over limit
Discharged 16.1 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
758% over limit
Discharged 10.3 mg/L against a permitted limit of 1.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 15, 2026 (3 hours ago)