ALTO PASS STP, VILLAGE OF
NPDES ID: IL0080128
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: 5 effluent violations, 1 single-event violation, 12 permit schedule violations, 4 reporting violations.
Violations
June 30, 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]
90% over limit
Discharged 4.37 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
25% over limit
Discharged 15 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Nitrogen, ammonia total [as N]
7% over limit
Discharged 7.2 mg/L against a permitted limit of 6.7 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
167% over limit
Discharged 7.2 mg/L against a permitted limit of 2.7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
First flagged
April 14, 2026 (5 months ago)
Last confirmed
September 15, 2026 (5 days ago)