ILLINOIS AMERICAN WATER COMPANY - RIVER GRANGE WRF
NPDES ID: IL0024732
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: 7 effluent violations.
Violations
April 30, 2026
Solids, total suspended
78% over limit
Discharged 21.4 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
14% over limit
Discharged 11.4 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
813% over limit
Discharged 10.95 mg/L against a permitted limit of 1.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
39% over limit
Discharged 1.13499999 kg/d against a permitted limit of 0.8172 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
611% over limit
Discharged 0.58112 kg/d against a permitted limit of 0.08172 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
265% over limit
Discharged 10.95 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
191% over limit
Discharged 0.58112 kg/d against a permitted limit of 0.19976 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
157% over limit
Discharged 6.43 mg/L against a permitted limit of 2.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
24% over limit
Discharged 6.43 mg/L against a permitted limit of 5.2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
225% over limit
Discharged 8.12 mg/L against a permitted limit of 2.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
56% over limit
Discharged 8.12 mg/L against a permitted limit of 5.2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
Coliform, fecal general
253% over limit
Discharged 1413.6 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2025
Nitrogen, ammonia total [as N]
242% over limit
Discharged 20.5 mg/L against a permitted limit of 6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
186% over limit
Discharged 0.46762 kg/d against a permitted limit of 0.16344 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
17% over limit
Discharged 0.46762 kg/d against a permitted limit of 0.39952 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
720% over limit
Discharged 20.5 mg/L against a permitted limit of 2.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)