SIOUX RAPIDS CITY OF STP
NPDES ID: IA0042951
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: 6 effluent violations.
Violations
May 31, 2026
Solids, total suspended
3% over limit
Discharged 82 mg/L against a permitted limit of 80 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
E. coli
13% over limit
Discharged 142.088 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
April 30, 2026
Nitrogen, ammonia total [as N]
1% over limit
Discharged 42.2 mg/L against a permitted limit of 41.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
18% over limit
Discharged 94 mg/L against a permitted limit of 80 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
27% over limit
Discharged 31.76 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
19% over limit
Discharged 47.4 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, carbonaceous [5 day, 20 C]
47% over limit
Discharged 36.65 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
4% over limit
Discharged 41.7 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
73% over limit
Discharged 43.325 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
11% over limit
Discharged 44.4 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
January 31, 2026
BOD, carbonaceous [5 day, 20 C]
36% over limit
Discharged 33.975 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
December 31, 2025
BOD, carbonaceous [5 day, 20 C]
68% over limit
Discharged 41.94 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
86% over limit
Discharged 74.2 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
0% over limit
Discharged 40.76 mg/L against a permitted limit of 40.7 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
5% over limit
Discharged 42.7 mg/L against a permitted limit of 40.7 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2025
Chlorine, total residual
0% over limit
Discharged 0 kg/d against a permitted limit of 0.05448 kg/d (DAILY MX)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.17 mg/L (DAILY MX)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.17 mg/L (30DA AVG)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 kg/d against a permitted limit of 0.05448 kg/d (30DA AVG)
DMR, Limited - Overdue
June 30, 2025
BOD, carbonaceous [5 day, 20 C]
65% over limit
Discharged 65.8 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
0% over limit
Discharged 2.94469936 kg/d against a permitted limit of 14.43719988 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 34 mg/L against a permitted limit of 47.5 mg/L (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 3.74849637 kg/d against a permitted limit of 68.09999943 kg/d (7 DA AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 7.4 SU against a permitted limit of 6 SU (DAILY MN)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 17.2825 mg/L against a permitted limit of 47.5 mg/L (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 5.79313075 kg/d against a permitted limit of 14.43719988 kg/d (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 21.675 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.17 mg/L (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 33.4 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 8.1 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 22 mg/L against a permitted limit of 80 mg/L (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 22 mg/L against a permitted limit of 120 mg/L (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 3.74849637 kg/d against a permitted limit of 45.39999962 kg/d (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 5.69089903 kg/d against a permitted limit of 22.69999981 kg/d (7 DA AVG)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 kg/d against a permitted limit of 0.05448 kg/d (DAILY MX)
DMR, Limited - Overdue
E. coli
0% over limit
Discharged 0 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.17 mg/L (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 3.69312063 kg/d against a permitted limit of 14.07399988 kg/d (30DA AVG)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 kg/d against a permitted limit of 0.05448 kg/d (30DA AVG)
DMR, Limited - Overdue
April 30, 2025
BOD, carbonaceous [5 day, 20 C]
31% over limit
Discharged 32.84 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 40.1 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
E. coli
120% over limit
Discharged 276.9755 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
March 31, 2025
BOD, carbonaceous [5 day, 20 C]
22% over limit
Discharged 30.4 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
January 31, 2025
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 28.60199976 kg/d (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 28.60199976 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 22.69999981 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 kg/d (7 DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 kg/d against a permitted limit of 14.21019988 kg/d (30DA AVG)
DMR, Limited - Overdue
December 31, 2024
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 kg/d against a permitted limit of 22.69999981 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 12.66659989 kg/d (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 kg/d against a permitted limit of 14.21019988 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 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 12.66659989 kg/d (30DA AVG)
DMR, Limited - Overdue
November 30, 2024
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.17 mg/L (DAILY MX)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 kg/d against a permitted limit of 0.05448 kg/d (DAILY MX)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 mg/L against a permitted limit of 0.17 mg/L (30DA AVG)
DMR, Limited - Overdue
Chlorine, total residual
0% over limit
Discharged 0 kg/d against a permitted limit of 0.05448 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 12.0309999 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 22.69999981 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 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 12.0309999 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 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 14.21019988 kg/d (30DA AVG)
DMR, Limited - Overdue
October 31, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 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 22.69999981 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 12.0309999 kg/d (DAILY MX)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0 kg/d against a permitted limit of 14.21019988 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 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 12.0309999 kg/d (30DA AVG)
DMR, Limited - Overdue
September 30, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 12.0309999 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 12.0309999 kg/d (DAILY MX)
DMR, Limited - Overdue
August 31, 2024
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 12.71199989 kg/d (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 12.71199989 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 kg/d (30DA AVG)
DMR, Limited - Overdue
July 31, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 45.44539962 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 68.14539943 kg/d (7 DA AVG)
DMR, Limited - Overdue
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)