CITY OF NORWALK WWTP
NPDES ID: OH0052604
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: 5 effluent violations.
Violations
May 31, 2026
E. coli, MTEC-MF
310% over limit
Discharged 516.04 MPN/100mL against a permitted limit of 126 MPN/100mL (MO GEOMN)
DMR, Limited - Numeric Violation
E. coli, MTEC-MF
330% over limit
Discharged 1220 MPN/100mL against a permitted limit of 284 MPN/100mL (WK GEOMN)
DMR, Limited - Numeric Violation
Solids, total suspended
18% over limit
Discharged 468 kg/d against a permitted limit of 397 kg/d (WKLY MAX)
DMR, Limited - Numeric Violation
April 30, 2026
Mercury, total low level
54% over limit
Discharged 0.00000338 mg/L against a permitted limit of 0.0000022 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Mercury, total low level
34% over limit
Discharged 0.0000389 kg/d against a permitted limit of 0.000029 kg/d (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Mercury, total low level
582% over limit
Discharged 0.000015 mg/L against a permitted limit of 0.0000022 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Mercury, total low level
200% over limit
Discharged 0.000087 kg/d against a permitted limit of 0.000029 kg/d (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Toxicity [chronic], Pimephales promelas [Fathead Minnow]
41% over limit
Discharged 1.41 toxic against a permitted limit of 1 toxic (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2025
Phosphorus, total [as P]
5% over limit
Discharged 21 kg/d against a permitted limit of 20 kg/d (WKLY MAX)
DMR, Limited - Numeric Violation
November 30, 2024
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)