COWDEN STP
NPDES ID: IL0028231
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
This quarter: 1 compliance schedule violation, 2 permit schedule violations.
Violations
August 31, 2025
Oxygen, dissolved [DO]
48% over limit
Discharged 2.1 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
62% over limit
Discharged 2.1 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
40% over limit
Discharged 2.1 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 2420 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
20% over limit
Discharged 36 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2025
Coliform, fecal general
Limit violation
Discharged 2420 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (5 months ago)
Last confirmed
September 15, 2026 (5 days ago)