OAK CREEK TOWN OF
NPDES ID: COG589159
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: 3 effluent violations.
Violations
May 31, 2026
Solids, suspended percent removal
13% over limit
Discharged 83 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
April 30, 2026
Solids, suspended percent removal
20% over limit
Discharged 82 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
27% over limit
Discharged 81 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
December 31, 2025
Iron, dissolved [as Fe]
94% over limit
Discharged 0.66300003 mg/L against a permitted limit of 0.34200002 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Iron, dissolved [as Fe]
94% over limit
Discharged 0.66300003 mg/L against a permitted limit of 0.34200002 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
October 31, 2025
Iron, dissolved [as Fe]
94% over limit
Discharged 0.66300003 mg/L against a permitted limit of 0.34200002 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
August 31, 2025
Sulfide-hydrogen sulfide [undissociated]
1100% over limit
Discharged 0.03 mg/L against a permitted limit of 0.0025 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
May 31, 2025
BOD, 5-day, percent removal
20% over limit
Discharged 82 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
April 30, 2025
Solids, suspended percent removal
273% over limit
Discharged 44 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
March 31, 2025
Mercury, total [low level]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (30DA AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
10% over limit
Discharged 2.41 mg/L against a permitted limit of 2.2 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Cyanide, weak acid, dissociable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
January 31, 2025
Cyanide, weak acid, dissociable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
December 31, 2024
Static Renewal 7 Day Chronic Ceriodaphnia dubia
64% over limit
Discharged 28.55 toxic against a permitted limit of 80 toxic (MN VALUE)
DMR, Limited - Numeric Violation
August 31, 2024
Manganese, dissolved [as Mn]
9% over limit
Discharged 0.23600001 mg/L against a permitted limit of 0.21700001 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Iron, total recoverable
142% over limit
Discharged 2.75000013 mg/L against a permitted limit of 1.13600005 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
July 31, 2024
Nitrogen, ammonia total [as N]
30% over limit
Discharged 3 mg/L against a permitted limit of 2.3 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Manganese, dissolved [as Mn]
42% over limit
Discharged 0.30900001 mg/L against a permitted limit of 0.21700001 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)