HOLSTEIN CITY OF STP
NPDES ID: IA0021954
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: 4 effluent violations.
Violations
June 30, 2026
Nitrogen, ammonia total [as N]
30% over limit
Discharged 23.33533648 kg/d against a permitted limit of 17.93299985 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
83% over limit
Discharged 2.38 mg/L against a permitted limit of 1.3 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Nitrogen, ammonia total [as N]
42% over limit
Discharged 2.275 mg/L against a permitted limit of 1.6 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.1 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
Nitrogen, ammonia total [as N]
193% over limit
Discharged 2.93 mg/L against a permitted limit of 1 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
9% over limit
Discharged 2.93 mg/L against a permitted limit of 2.7 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
116% over limit
Discharged 28.2897885 kg/d against a permitted limit of 13.07519989 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
July 31, 2025
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 120 mg/L (7 DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 80 mg/L (30DA AVG)
DMR, Limited - Overdue
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 16, 2026 (18 minutes ago)