ALLERTON CITY OF STP (SOUTH)
NPDES ID: IA0054046
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
Nitrogen, ammonia total [as N]
509% over limit
Discharged 19.5 mg/L against a permitted limit of 3.2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
55% over limit
Discharged 2.63 mg/L against a permitted limit of 1.7 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
April 30, 2026
BOD, carbonaceous [5 day, 20 C]
7% over limit
Discharged 26.66666 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
104% over limit
Discharged 6.94375 mg/L against a permitted limit of 3.4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
133% over limit
Discharged 9.07 mg/L against a permitted limit of 3.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 kg/d against a permitted limit of 19.97599983 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 95.3399992 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 63.55999947 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 3.13259997 kg/d (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 kg/d against a permitted limit of 31.77999973 kg/d (7 DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 6.67379994 kg/d (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
5% over limit
Discharged 8.79 mg/L against a permitted limit of 8.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
64% over limit
Discharged 6.54875 mg/L against a permitted limit of 4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
October 31, 2025
pH
0% over limit
Discharged 9.1 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
pH
0% over limit
Discharged 9.4 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
pH
0% over limit
Discharged 9.1 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2025
pH
0% over limit
Discharged 9.5 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
95% over limit
Discharged 0.25 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
June 30, 2025
Oxygen, dissolved [DO]
98% over limit
Discharged 0.1 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
April 30, 2025
Nitrogen, ammonia total [as N]
14% over limit
Discharged 2.391 mg/L against a permitted limit of 2.1 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
March 31, 2025
Nitrogen, ammonia total [as N]
92% over limit
Discharged 8.655 mg/L against a permitted limit of 4.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
24% over limit
Discharged 10.4 mg/L against a permitted limit of 8.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2025
Nitrogen, ammonia total [as N]
20% over limit
Discharged 6.97875 mg/L against a permitted limit of 5.8 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
September 30, 2024
pH
0% over limit
Discharged 9.1 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
23% over limit
Discharged 1.84375 mg/L against a permitted limit of 1.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
August 31, 2024
pH
0% over limit
Discharged 9.3 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2024
Oxygen, dissolved [DO]
7% over limit
Discharged 4.64 mg/L against a permitted limit of 5 mg/L (DAILY MN)
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
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)