DELAVAN STP, CITY OF
NPDES ID: ILG582018
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
June 30, 2026
Solids, total suspended
103% over limit
Discharged 91.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.535 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Numeric Violation
Solids, total suspended
147% over limit
Discharged 91.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2026
Solids, total suspended
107% over limit
Discharged 93 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.255 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Numeric Violation
Solids, total suspended
151% over limit
Discharged 93 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Solids, total suspended
20% over limit
Discharged 44.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
pH
0% over limit
Discharged 9.16 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Numeric Violation
Solids, total suspended
54% over limit
Discharged 69.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
88% over limit
Discharged 69.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
pH
0% over limit
Discharged 9.16 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Numeric Violation
January 31, 2026
Solids, total suspended
22% over limit
Discharged 45 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2025
Solids, total suspended
14% over limit
Discharged 42 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Solids, total suspended
134% over limit
Discharged 105.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
185% over limit
Discharged 105.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2025
Solids, total suspended
84% over limit
Discharged 68 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
51% over limit
Discharged 68 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
August 31, 2025
Oxygen, dissolved [DO]
45% over limit
Discharged 3.3 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
July 31, 2025
Oxygen, dissolved [DO]
64% over limit
Discharged 2.15 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
June 30, 2025
pH
0% over limit
Discharged 9.06 SU against a permitted limit of 9 SU (MAXIMUM)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
16% over limit
Discharged 5.06 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Solids, total suspended
28% over limit
Discharged 57.4 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
55% over limit
Discharged 57.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Solids, total suspended
30% over limit
Discharged 58.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
58% over limit
Discharged 58.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2025
Solids, total suspended
80% over limit
Discharged 66.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
48% over limit
Discharged 66.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Solids, total suspended
22% over limit
Discharged 45 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2025
Solids, total suspended
16% over limit
Discharged 43 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2024
Solids, total suspended
15% over limit
Discharged 42.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
Solids, total suspended
77% over limit
Discharged 79.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
115% over limit
Discharged 79.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2024
Solids, total suspended
11% over limit
Discharged 41 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2024
Solids, total suspended
31% over limit
Discharged 48.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
8% over limit
Discharged 48.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
August 31, 2024
Solids, total suspended
128% over limit
Discharged 84.5 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
88% over limit
Discharged 84.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
August 1, 2026 (4 days ago)