FOUR CORNERS TREATMENT PLANT
NPDES ID: LA0088765
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: 9 effluent violations.
Violations
June 30, 2026
BOD, 5-day, 20 deg. C
60% over limit
Discharged 16 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
4% over limit
Discharged 208.3 MPN/100mL against a permitted limit of 200 MPN/100mL (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
196% over limit
Discharged 17.47899985 kg/d against a permitted limit of 5.90199995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
60% over limit
Discharged 24 mg/L against a permitted limit of 15 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
May 31, 2026
BOD, 5-day, 20 deg. C
100% over limit
Discharged 20 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
147% over limit
Discharged 37 mg/L against a permitted limit of 15 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
28% over limit
Discharged 7.58179994 kg/d against a permitted limit of 5.90199995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
82% over limit
Discharged 727 MPN/100mL against a permitted limit of 400 MPN/100mL (WKLY AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Chlorine, total residual
15658% over limit
Discharged 5.2 mg/L against a permitted limit of 0.033 mg/L (INST MAX)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, 5-day, 20 deg. C
40% over limit
Discharged 14 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2025
BOD, 5-day, 20 deg. C
55% over limit
Discharged 9.12539992 kg/d against a permitted limit of 5.90199995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
22% over limit
Discharged 488.4 MPN/100mL against a permitted limit of 400 MPN/100mL (WKLY AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
70% over limit
Discharged 339.4 MPN/100mL against a permitted limit of 200 MPN/100mL (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
10% over limit
Discharged 11 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
BOD, 5-day, 20 deg. C
20% over limit
Discharged 12 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2024
BOD, 5-day, 20 deg. C
40% over limit
Discharged 14 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
20% over limit
Discharged 18 mg/L against a permitted limit of 15 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
September 30, 2024
BOD, 5-day, 20 deg. C
198% over limit
Discharged 17.61519985 kg/d against a permitted limit of 5.90199995 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
180% over limit
Discharged 28 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
160% over limit
Discharged 39 mg/L against a permitted limit of 15 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 16, 2026 (22 minutes ago)