WALKER HILL ENVIRONMENTAL INC
NPDES ID: MSP092171
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: 2 effluent violations.
Violations
May 31, 2026
Benzene, ethylbenzene, toluene, xylene combination
32% over limit
Discharged 9.911 mg/L against a permitted limit of 7.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Benzene, ethylbenzene, toluene, xylene combination
4% over limit
Discharged 5.22 mg/L against a permitted limit of 5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Benzene, ethylbenzene, toluene, xylene combination
238% over limit
Discharged 16.885 mg/L against a permitted limit of 5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Benzene, ethylbenzene, toluene, xylene combination
143% over limit
Discharged 18.206 mg/L against a permitted limit of 7.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Benzene
1531% over limit
Discharged 8.153 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Benzene
1980% over limit
Discharged 15.6 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Benzene
14% over limit
Discharged 0.852 mg/L against a permitted limit of 0.75 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Benzene, ethylbenzene, toluene, xylene combination
112% over limit
Discharged 10.623 mg/L against a permitted limit of 5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Benzene, ethylbenzene, toluene, xylene combination
132% over limit
Discharged 17.382 mg/L against a permitted limit of 7.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
August 1, 2026 (5 days ago)