SOUTHWESTERN SENIOR HIGH SCHOOL STP
NPDES ID: IL0045641
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
This quarter: 4 effluent violations, 1 compliance schedule violation.
Violations
May 31, 2026
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
April 30, 2026
Oxygen, dissolved [DO]
37% over limit
Discharged 3.8 mg/L against a permitted limit of 6 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
24% over limit
Discharged 3.8 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
83% over limit
Discharged 2.74 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]
49% over limit
Discharged 2.23 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
1% over limit
Discharged 0.3632 kg/d against a permitted limit of 0.35866 kg/d (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (5 months ago)
Last confirmed
September 15, 2026 (5 days ago)