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: 2 effluent violations, 1 single-event violation, 12 permit schedule violations, 4 reporting violations.
Violations
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
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
704% over limit
Discharged 21.7 mg/L against a permitted limit of 2.7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
224% over limit
Discharged 21.7 mg/L against a permitted limit of 6.7 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
45% over limit
Discharged 21.7 mg/L against a permitted limit of 15 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
120% over limit
Discharged 22 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
10% over limit
Discharged 22 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
23% over limit
Discharged 4.9 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2025
Coliform, fecal general
175% over limit
Discharged 1100 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Coliform, fecal general
100% over limit
Discharged 800 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
BOD, carbonaceous [5 day, 20 C]
30% over limit
Discharged 13 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
200% over limit
Discharged 1200 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2025
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 7.71799994 kg/d (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 15.43599987 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Overdue
March 31, 2025
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 15.43599987 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 7.71799994 kg/d (MO AVG)
DMR, Limited - Overdue
February 28, 2025
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 15.43599987 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 7.71799994 kg/d (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 5 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.61 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0.378636 kg/d against a permitted limit of 6.35599995 kg/d (MO AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 7.2 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.2 mg/L against a permitted limit of 10 mg/L (WKLY AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.0908 kg/d against a permitted limit of 6.35599995 kg/d (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0.378636 kg/d against a permitted limit of 13.16599989 kg/d (DAILY MX)
DMR, Limited - Overdue
pH
0% over limit
Discharged 7.2 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.61 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.025 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.2 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.0908 kg/d against a permitted limit of 6.35599995 kg/d (WKLY AVG)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.05 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.2 mg/L against a permitted limit of 10.1 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.0908 kg/d against a permitted limit of 2.58779998 kg/d (MO AVG)
DMR, Limited - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 54 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 5 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.02 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 6.61 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 65 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.02 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 0.025 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
January 31, 2025
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 7.71799994 kg/d (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 15.43599987 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.02 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 5 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.016 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Monitor Only - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.05 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.6 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0.29964 kg/d against a permitted limit of 6.35599995 kg/d (MO AVG)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 7.4 mg/L against a permitted limit of 4 mg/L (MN WK AV)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.6 mg/L against a permitted limit of 10.1 mg/L (DAILY MX)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 7.4 mg/L against a permitted limit of 5.5 mg/L (MO AV MN)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.016 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
pH
0% over limit
Discharged 7.44 SU against a permitted limit of 6 SU (MINIMUM)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.03632 kg/d against a permitted limit of 6.35599995 kg/d (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 5 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.03632 kg/d against a permitted limit of 6.35599995 kg/d (WKLY AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.03632 kg/d against a permitted limit of 2.58779998 kg/d (MO AVG)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 7.4 mg/L against a permitted limit of 3.5 mg/L (DAILY MN)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.02 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 27 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.6 mg/L against a permitted limit of 10 mg/L (WKLY AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 7.44 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0.29964 kg/d against a permitted limit of 13.16599989 kg/d (DAILY MX)
DMR, Limited - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 118 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)