OELWEIN CITY OF STP
NPDES ID: IA0032344
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: 7 effluent violations.
Violations
May 31, 2026
Nitrogen, ammonia total [as N]
57% over limit
Discharged 14.4 mg/L against a permitted limit of 9.2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
92% over limit
Discharged 40.72966988 kg/d against a permitted limit of 21.20179982 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
286% over limit
Discharged 9.643076 mg/L against a permitted limit of 2.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Nitrogen, ammonia total [as N]
120% over limit
Discharged 6.168181 mg/L against a permitted limit of 2.8 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
59% over limit
Discharged 38.69964521 kg/d against a permitted limit of 24.3797998 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
3% over limit
Discharged 9.41 mg/L against a permitted limit of 9.1 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 5.63 SU against a permitted limit of 6.5 SU (DAILY MN)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
92% over limit
Discharged 7.50125 mg/L against a permitted limit of 3.9 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
35% over limit
Discharged 9.95625 mg/L against a permitted limit of 7.4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
September 30, 2024
E. coli
51% over limit
Discharged 190 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)