GROTON WPCF
NPDES ID: CT0100242
X — SNC: Effluent violation (non-monthly average limit)
The facility discharged more of a pollutant than its permit allows, measured over a period other than a monthly average.
This quarter: 10 effluent violations, 2 single-event violations.
Violations
May 31, 2026
Coliform, fecal - % samples exceeding limit
20% over limit
Discharged 12 % against a permitted limit of 10 % (INST MAX)
DMR, Limited - Numeric Violation
Solids, total suspended
414% over limit
Discharged 257 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
17% over limit
Discharged 35 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Enterococci
384% over limit
Discharged 2419 MPN/100mL against a permitted limit of 500 MPN/100mL (MAXIMUM)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
33% over limit
Discharged 80 % against a permitted limit of 85 % (MINIMUM)
DMR, Limited - Numeric Violation
April 30, 2026
Enterococci
37% over limit
Discharged 686 MPN/100mL against a permitted limit of 500 MPN/100mL (MAXIMUM)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
120% over limit
Discharged 110 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
122% over limit
Discharged 111 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
10% over limit
Discharged 33 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Solids, total suspended
97% over limit
Discharged 59 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
256% over limit
Discharged 178 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
173% over limit
Discharged 59 % against a permitted limit of 85 % (MINIMUM)
DMR, Limited - Numeric Violation
Enterococci
54% over limit
Discharged 770.1 MPN/100mL against a permitted limit of 500 MPN/100mL (MAXIMUM)
DMR, Limited - Numeric Violation
February 28, 2026
Solids, total suspended
56% over limit
Discharged 78 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Solids, total suspended
6% over limit
Discharged 53 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Solids, total suspended
128% over limit
Discharged 114 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
May 31, 2025
BOD, 5-day, 20 deg. C
10% over limit
Discharged 55 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
164% over limit
Discharged 132 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
20% over limit
Discharged 82 % against a permitted limit of 85 % (MINIMUM)
DMR, Limited - Numeric Violation
April 30, 2025
Solids, total suspended
94% over limit
Discharged 97 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2025
Solids, suspended percent removal
87% over limit
Discharged 72 % against a permitted limit of 85 % (MINIMUM)
DMR, Limited - Numeric Violation
Chlorine, total residual
80% over limit
Discharged 0.04 mg/L against a permitted limit of 0.2 mg/L (INST MIN)
DMR, Limited - Numeric Violation
Solids, total suspended
43% over limit
Discharged 43 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
66% over limit
Discharged 83 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
328% over limit
Discharged 214 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Enterococci
384% over limit
Discharged 2419 MPN/100mL against a permitted limit of 500 MPN/100mL (MAXIMUM)
DMR, Limited - Numeric Violation
February 28, 2025
Chlorine, total residual
7% over limit
Discharged 1.6 mg/L against a permitted limit of 1.5 mg/L (INST MAX)
DMR, Limited - Numeric Violation
Solids, total suspended
50% over limit
Discharged 75 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2025
Solids, total suspended
2% over limit
Discharged 51 mg/L against a permitted limit of 50 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Coliform, fecal - % samples exceeding limit
130% over limit
Discharged 23 % against a permitted limit of 10 % (INST MAX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)