SHIPMAN STP
NPDES ID: IL0063088
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: 3 effluent violations.
Violations
May 31, 2026
Nitrogen, ammonia total [as N]
7% over limit
Discharged 1.6 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
39% over limit
Discharged 2.5 mg/L against a permitted limit of 1.8 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
70% over limit
Discharged 17 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
18% over limit
Discharged 5.8 mg/L against a permitted limit of 4.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
45% over limit
Discharged 5.8 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
18% over limit
Discharged 4.5 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
January 31, 2026
pH
0% over limit
Discharged 4.2 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
80% over limit
Discharged 7.2 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
47% over limit
Discharged 7.2 mg/L against a permitted limit of 4.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2025
Nitrogen, ammonia total [as N]
613% over limit
Discharged 10.7 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
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]
257% over limit
Discharged 10.7 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, ammonia total [as N]
627% over limit
Discharged 10.9 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
13% over limit
Discharged 1.95219998 kg/d against a permitted limit of 1.72519999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
263% over limit
Discharged 10.9 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
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
July 31, 2025
Oxygen, dissolved [DO]
6% over limit
Discharged 4.72 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
21% over limit
Discharged 4.72 mg/L against a permitted limit of 6 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
June 30, 2025
Oxygen, dissolved [DO]
17% over limit
Discharged 5 mg/L against a permitted limit of 6 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
7% over limit
Discharged 1.6 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Oxygen, dissolved [DO]
23% over limit
Discharged 4.6 mg/L against a permitted limit of 6 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
8% over limit
Discharged 4.6 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
April 30, 2025
Nitrogen, ammonia total [as N]
7% over limit
Discharged 1.6 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Oxygen, dissolved [DO]
4% over limit
Discharged 5.3 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
December 31, 2024
Oxygen, dissolved [DO]
40% over limit
Discharged 3.3 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
6% over limit
Discharged 3.3 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
150% over limit
Discharged 10 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
18% over limit
Discharged 3.3 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
104% over limit
Discharged 10 mg/L against a permitted limit of 4.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2024
Nitrogen, ammonia total [as N]
122% over limit
Discharged 10.9 mg/L against a permitted limit of 4.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
20% over limit
Discharged 3.2 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
173% over limit
Discharged 10.9 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
42% over limit
Discharged 3.2 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
9% over limit
Discharged 3.2 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
October 31, 2024
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
Solids, total suspended
8% over limit
Discharged 13 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
31% over limit
Discharged 3.8 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
5% over limit
Discharged 3.8 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
September 30, 2024
BOD, carbonaceous [5 day, 20 C]
60% over limit
Discharged 16 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
13% over limit
Discharged 4.8 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
27% over limit
Discharged 3.8 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]
153% over limit
Discharged 3.8 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2024
Solids, total suspended
8% over limit
Discharged 26 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
71% over limit
Discharged 1 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Solids, total suspended
117% over limit
Discharged 26 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
75% over limit
Discharged 1 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
80% over limit
Discharged 2.7 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
80% over limit
Discharged 18 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
82% over limit
Discharged 1 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
August 1, 2026 (4 days ago)