WINTERSET CITY OF STP
NPDES ID: IA0034291
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
Oxygen, dissolved [DO]
5% over limit
Discharged 4.28 mg/L against a permitted limit of 4.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
E. coli
371% over limit
Discharged 593.71 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
8% over limit
Discharged 3.87125 mg/L against a permitted limit of 3.6 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Solids, total suspended
109% over limit
Discharged 94 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
10% over limit
Discharged 328.44094004 kg/d against a permitted limit of 298.27799749 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
77% over limit
Discharged 0.0495 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
31% over limit
Discharged 39.25 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Solids, total suspended
33% over limit
Discharged 39.8 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
32% over limit
Discharged 0.0368 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
27% over limit
Discharged 57 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
4% over limit
Discharged 0.18766044 kg/d against a permitted limit of 0.1805558 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
Copper, total [as Cu]
141% over limit
Discharged 0.0672 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
77% over limit
Discharged 44.125 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
127% over limit
Discharged 33.8 mg/L against a permitted limit of 14.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
80% over limit
Discharged 72 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
122% over limit
Discharged 100 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
120% over limit
Discharged 66 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
71% over limit
Discharged 21.66375 mg/L against a permitted limit of 12.7 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
51% over limit
Discharged 0.042025 mg/L against a permitted limit of 0.0279 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Copper, total [as Cu]
126% over limit
Discharged 0.0631 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
34% over limit
Discharged 0.037525 mg/L against a permitted limit of 0.0279 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
22% over limit
Discharged 36.5 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
2% over limit
Discharged 46 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
October 31, 2025
Copper, total [as Cu]
140% over limit
Discharged 0.067 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
20% over limit
Discharged 0.0335 mg/L against a permitted limit of 0.0279 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
E. coli
87% over limit
Discharged 235 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
July 31, 2025
Solids, total suspended
21% over limit
Discharged 36.2 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
38% over limit
Discharged 62 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
33% over limit
Discharged 397.29816606 kg/d against a permitted limit of 298.27799749 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
8% over limit
Discharged 0.19493125 kg/d against a permitted limit of 0.1805558 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
4% over limit
Discharged 0.029 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
Copper, total [as Cu]
4% over limit
Discharged 0.18816075 kg/d against a permitted limit of 0.1805558 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
29% over limit
Discharged 0.036 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2025
Nitrogen, ammonia total [as N]
60% over limit
Discharged 157.06878968 kg/d against a permitted limit of 98.47259917 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
148% over limit
Discharged 14.40375 mg/L against a permitted limit of 5.8 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
27% over limit
Discharged 38 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
118% over limit
Discharged 33.4 mg/L against a permitted limit of 15.3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
94% over limit
Discharged 45.23624182 kg/d against a permitted limit of 23.2901998 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
2% over limit
Discharged 46 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Oil & Grease
0% over limit
Discharged 0 mg/L against a permitted limit of 15 mg/L (DAILY MX)
DMR, Limited - Overdue
Oil & Grease
0% over limit
Discharged 0 mg/L against a permitted limit of 10 mg/L (30DA AVG)
DMR, Limited - Overdue
December 31, 2024
Copper, total [as Cu]
6% over limit
Discharged 0.0295 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2024
Nitrogen, ammonia total [as N]
30% over limit
Discharged 21.1 mg/L against a permitted limit of 16.2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Oxygen, dissolved [DO]
42% over limit
Discharged 2.61 mg/L against a permitted limit of 4.5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
July 31, 2024
Solids, total suspended
136% over limit
Discharged 106 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
68% over limit
Discharged 0.0469 mg/L against a permitted limit of 0.0279 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
143% over limit
Discharged 726.0495059 kg/d against a permitted limit of 298.27799749 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
5% over limit
Discharged 31.4 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
E. coli
26% over limit
Discharged 159 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
77% over limit
Discharged 0.32124268 kg/d against a permitted limit of 0.181146 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (24 days ago)