NIANTIC STP, VILLAGE OF
NPDES ID: ILG580149
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
This quarter: 3 effluent violations.
Violations
May 31, 2026
Oxygen, dissolved [DO]
53% over limit
Discharged 2.81 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
April 30, 2026
Oxygen, dissolved [DO]
61% over limit
Discharged 2.34 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, carbonaceous [5 day, 20 C]
20% over limit
Discharged 30 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
53% over limit
Discharged 2.8 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
January 31, 2026
BOD, carbonaceous [5 day, 20 C]
18% over limit
Discharged 47 mg/L against a permitted limit of 40 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
38% over limit
Discharged 3.7 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
48% over limit
Discharged 37 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
24% over limit
Discharged 56 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Solids, total suspended
16% over limit
Discharged 52 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
3% over limit
Discharged 38 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
60% over limit
Discharged 2.4 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
August 31, 2025
Oxygen, dissolved [DO]
65% over limit
Discharged 2.1 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
June 30, 2025
Oxygen, dissolved [DO]
60% over limit
Discharged 2.4 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
May 31, 2025
Solids, total suspended
24% over limit
Discharged 56 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
37% over limit
Discharged 3.8 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Solids, total suspended
11% over limit
Discharged 41 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2025
Oxygen, dissolved [DO]
35% over limit
Discharged 3.9 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
2% over limit
Discharged 24.0619998 kg/d against a permitted limit of 23.6079998 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
5% over limit
Discharged 39 mg/L against a permitted limit of 37 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
BOD, carbonaceous [5 day, 20 C]
2% over limit
Discharged 24.0619998 kg/d against a permitted limit of 23.6079998 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
18% over limit
Discharged 47 mg/L against a permitted limit of 40 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
86% over limit
Discharged 46.5 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2025
BOD, carbonaceous [5 day, 20 C]
32% over limit
Discharged 33 mg/L against a permitted limit of 25 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2024
Oxygen, dissolved [DO]
40% over limit
Discharged 3.6 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
August 31, 2024
Oxygen, dissolved [DO]
60% over limit
Discharged 2.4 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
August 1, 2026 (5 days ago)