OSKALOOSA CITY OF STP (NORTHEAST)
NPDES ID: IA0038539
E — SNC: Effluent violation (monthly average limit)
The facility discharged more of a pollutant than its permit allows, based on a monthly average.
Violations
March 31, 2026
Copper, total [as Cu]
3% over limit
Discharged 0.01736 mg/L against a permitted limit of 0.01687 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
19% over limit
Discharged 0.032 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
Copper, total [as Cu]
31653% over limit
Discharged 50.70099437 kg/d against a permitted limit of 0.1596718 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
51651% over limit
Discharged 131.75960649 kg/d against a permitted limit of 0.2546032 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
183915% over limit
Discharged 49.5 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
116605% over limit
Discharged 19.68812 mg/L against a permitted limit of 0.01687 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Copper, total [as Cu]
41% over limit
Discharged 0.038 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Copper, total [as Cu]
4% over limit
Discharged 0.028 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
21% over limit
Discharged 3.93 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
60% over limit
Discharged 3.9955 mg/L against a permitted limit of 2.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
18% over limit
Discharged 2.71 mg/L against a permitted limit of 2.3 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
50% over limit
Discharged 0.02525 mg/L against a permitted limit of 0.01687 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
119% over limit
Discharged 0.059 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2025
Oxygen, dissolved [DO]
53% over limit
Discharged 2.35 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
73% over limit
Discharged 19.2 mg/L against a permitted limit of 11.1 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
1% over limit
Discharged 0.017 mg/L against a permitted limit of 0.01687 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
211% over limit
Discharged 4.981111 mg/L against a permitted limit of 1.6 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
0% over limit
Discharged 0.027 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, ammonia total [as N]
8% over limit
Discharged 10.76768135 kg/d against a permitted limit of 9.98799992 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
220% over limit
Discharged 3.521111 mg/L against a permitted limit of 1.1 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
125% over limit
Discharged 13.7 mg/L against a permitted limit of 6.1 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
Solids, total suspended
280% over limit
Discharged 171 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
54% over limit
Discharged 46.25 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
122% over limit
Discharged 628.69056872 kg/d against a permitted limit of 282.84199762 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
June 30, 2025
Copper, total [as Cu]
33% over limit
Discharged 0.0225 mg/L against a permitted limit of 0.01687 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
64% over limit
Discharged 2.13625 mg/L against a permitted limit of 1.3 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
41% over limit
Discharged 0.038 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
30% over limit
Discharged 3.51 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
February 28, 2025
Oxygen, dissolved [DO]
7% over limit
Discharged 4.65 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
51% over limit
Discharged 6.0525 mg/L against a permitted limit of 4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
January 31, 2025
Solids, total suspended
24% over limit
Discharged 55.66666 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
32% over limit
Discharged 0.0356 mg/L against a permitted limit of 0.0269 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2024
Nitrogen, ammonia total [as N]
0% over limit
Discharged 2.502 mg/L against a permitted limit of 2.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
October 31, 2024
Nitrogen, ammonia total [as N]
11% over limit
Discharged 1.774 mg/L against a permitted limit of 1.6 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
September 30, 2024
Nitrogen, ammonia total [as N]
41% over limit
Discharged 1.55 mg/L against a permitted limit of 1.1 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (22 days ago)