ILLINOIS AMERICAN WATER - TOLONO STP
NPDES ID: IL0031453
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: 13 effluent violations.
Violations
May 31, 2026
Solids, total suspended
304% over limit
Discharged 97 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
120% over limit
Discharged 26.4 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
13% over limit
Discharged 1.7 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
77% over limit
Discharged 94.8859992 kg/d against a permitted limit of 53.572 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
187% over limit
Discharged 8.6 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
24% over limit
Discharged 8.44439993 kg/d against a permitted limit of 6.80999994 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2026
Solids, total suspended
85% over limit
Discharged 22.2 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
533% over limit
Discharged 19 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
153% over limit
Discharged 17.20659986 kg/d against a permitted limit of 6.80999994 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
440% over limit
Discharged 8.1 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
44% over limit
Discharged 77.17999935 kg/d against a permitted limit of 53.572 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
240% over limit
Discharged 81.6 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
118% over limit
Discharged 7.32301994 kg/d against a permitted limit of 3.35959997 kg/d (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
118% over limit
Discharged 7.80879993 kg/d against a permitted limit of 3.58659997 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
442% over limit
Discharged 130 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
90% over limit
Discharged 7.6 mg/L against a permitted limit of 4 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
228% over limit
Discharged 39.3 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
103% over limit
Discharged 14 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 2419.6 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
90% over limit
Discharged 101.69599915 kg/d against a permitted limit of 53.572 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
29% over limit
Discharged 34.50399971 kg/d against a permitted limit of 26.786 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
419% over limit
Discharged 8.3 mg/L against a permitted limit of 1.6 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
20% over limit
Discharged 12 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
128% over limit
Discharged 9.1 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
78% over limit
Discharged 21.3 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
177% over limit
Discharged 13 mg/L against a permitted limit of 4.7 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
15% over limit
Discharged 23 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
25% over limit
Discharged 30 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Solids, total suspended
15% over limit
Discharged 13.8 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
72% over limit
Discharged 8.1 mg/L against a permitted limit of 4.7 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
4% over limit
Discharged 25 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Solids, total suspended
67% over limit
Discharged 40 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
117% over limit
Discharged 8.69 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
108% over limit
Discharged 24.9 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
198% over limit
Discharged 14 mg/L against a permitted limit of 4.7 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2025
BOD, carbonaceous [5 day, 20 C]
20% over limit
Discharged 12 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
220% over limit
Discharged 38.4 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
179% over limit
Discharged 67 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
100% over limit
Discharged 9.4 mg/L against a permitted limit of 4.7 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2025
Nitrogen, ammonia total [as N]
267% over limit
Discharged 11 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
49% over limit
Discharged 14.9 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
117% over limit
Discharged 52 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
267% over limit
Discharged 44 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
340% over limit
Discharged 6.6 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Solids, total suspended
208% over limit
Discharged 74 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
103% over limit
Discharged 6.1 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
117% over limit
Discharged 26 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2025
Solids, total suspended
50% over limit
Discharged 18 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
25% over limit
Discharged 30 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
417% over limit
Discharged 15.5 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
42% over limit
Discharged 2.125 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2025
Solids, total suspended
233% over limit
Discharged 40 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
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
Nitrogen, ammonia total [as N]
587% over limit
Discharged 20.6 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
155% over limit
Discharged 51 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
60% over limit
Discharged 16 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
June 30, 2025
Solids, total suspended
104% over limit
Discharged 49 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
32% over limit
Discharged 13.19 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
117% over limit
Discharged 26 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
50% over limit
Discharged 30 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
May 31, 2025
Solids, total suspended
367% over limit
Discharged 56 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
25% over limit
Discharged 12.5 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
538% over limit
Discharged 153 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
131% over limit
Discharged 123.48799896 kg/d against a permitted limit of 53.572 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
25% over limit
Discharged 3.75 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
42% over limit
Discharged 38.13599968 kg/d against a permitted limit of 26.786 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
65% over limit
Discharged 33 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2025
Nitrogen, ammonia total [as N]
101% over limit
Discharged 13.70625988 kg/d against a permitted limit of 6.80999994 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
175% over limit
Discharged 66 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
633% over limit
Discharged 22 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
194% over limit
Discharged 9.88811992 kg/d against a permitted limit of 3.35959997 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
3% over limit
Discharged 10.3 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
987% over limit
Discharged 16.3 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
108% over limit
Discharged 24.9 mg/L against a permitted limit of 12 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
March 31, 2025
Solids, total suspended
921% over limit
Discharged 245 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
408% over limit
Discharged 61 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
35% over limit
Discharged 72.18599939 kg/d against a permitted limit of 53.572 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
89% over limit
Discharged 18.86 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
131% over limit
Discharged 9.25 mg/L against a permitted limit of 4 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
113% over limit
Discharged 14.7 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
193% over limit
Discharged 4.69 mg/L against a permitted limit of 1.6 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
100% over limit
Discharged 40 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2025
Solids, total suspended
212% over limit
Discharged 37.38 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
283% over limit
Discharged 92 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
55% over limit
Discharged 15.5 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
65% over limit
Discharged 33 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2025
Solids, total suspended
33% over limit
Discharged 32 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
20% over limit
Discharged 24 mg/L against a permitted limit of 20 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2024
Solids, total suspended
325% over limit
Discharged 102 mg/L against a permitted limit of 24 mg/L (DAILY MX)
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
Solids, total suspended
214% over limit
Discharged 37.67 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
10% over limit
Discharged 11 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
Solids, total suspended
25% over limit
Discharged 15 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
46% over limit
Discharged 35 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2024
Solids, total suspended
21% over limit
Discharged 29 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Solids, total suspended
68% over limit
Discharged 20.13 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
142% over limit
Discharged 58 mg/L against a permitted limit of 24 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2024
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.05 mg/L (DAILY MX)
DMR, Limited - Overdue
July 31, 2024
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]
78% over limit
Discharged 5.34 mg/L against a permitted limit of 3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)