TONICA STP, VILLAGE OF
NPDES ID: IL0023639
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: 9 effluent violations.
Violations
June 30, 2026
BOD, carbonaceous [5 day, 20 C]
102% over limit
Discharged 19.21600384 kg/d against a permitted limit of 9.534 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
25% over limit
Discharged 25 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
150% over limit
Discharged 25 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
150% over limit
Discharged 60 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
1% over limit
Discharged 19.21600384 kg/d against a permitted limit of 19.068 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
103% over limit
Discharged 46.11777361 kg/d against a permitted limit of 22.7 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
400% over limit
Discharged 60 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
306% over limit
Discharged 46.11777361 kg/d against a permitted limit of 11.35 kg/d (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2026
BOD, carbonaceous [5 day, 20 C]
100% over limit
Discharged 20 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2025
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.066 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.066 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.052 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.052 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
pH
0% over limit
Discharged 9.34 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Numeric Violation
July 31, 2025
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 1.61306199 kg/d against a permitted limit of 19.068 kg/d (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.071 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0.537536 kg/d against a permitted limit of 11.35 kg/d (MO AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.06129 kg/d against a permitted limit of 3.76819997 kg/d (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.06129 kg/d against a permitted limit of 0.95339999 kg/d (MO AVG)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.17 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.17 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.06129 kg/d against a permitted limit of 2.36079998 kg/d (WKLY AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 1.61306199 kg/d against a permitted limit of 9.534 kg/d (MO AVG)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.071 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0.537536 kg/d against a permitted limit of 22.7 kg/d (DAILY MX)
DMR, Limited - Overdue
October 31, 2024
Oxygen, dissolved [DO]
24% over limit
Discharged 4.2 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
September 30, 2024
Oxygen, dissolved [DO]
33% over limit
Discharged 2.7 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
51% over limit
Discharged 2.7 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
23% over limit
Discharged 2.7 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 15, 2026 (4 hours ago)