DERBY, CITY OF (WWTP)
NPDES ID: KS0050377
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: 5 effluent violations.
Violations
April 30, 2026
Phosphorus, Total As P
7% over limit
Discharged 10.14980551 kg/d against a permitted limit of 9.47951992 kg/d (DPD AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
126% over limit
Discharged 17.2 mg/L against a permitted limit of 7.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
101% over limit
Discharged 9.435 mg/L against a permitted limit of 4.7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
171% over limit
Discharged 20.6 mg/L against a permitted limit of 7.6 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
101% over limit
Discharged 25.3 mg/L against a permitted limit of 12.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Phosphorus, Total As P
6% over limit
Discharged 10.04460918 kg/d against a permitted limit of 9.47951992 kg/d (DPD AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Phosphorus, Total As P
7% over limit
Discharged 10.16437437 kg/d against a permitted limit of 9.47951992 kg/d (DPD AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
57% over limit
Discharged 19.8 mg/L against a permitted limit of 12.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
114% over limit
Discharged 19.45 mg/L against a permitted limit of 9.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
120% over limit
Discharged 20 mg/L against a permitted limit of 9.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
67% over limit
Discharged 21.1 mg/L against a permitted limit of 12.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Phosphorus, Total As P
5% over limit
Discharged 9.97389414 kg/d against a permitted limit of 9.47951992 kg/d (DPD AVG)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrogen, ammonia total [as N]
83% over limit
Discharged 16.65 mg/L against a permitted limit of 9.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Phosphorus, Total As P
2% over limit
Discharged 9.68212196 kg/d against a permitted limit of 9.47951992 kg/d (DPD AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
46% over limit
Discharged 18.4 mg/L against a permitted limit of 12.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
221% over limit
Discharged 27.25 mg/L against a permitted limit of 8.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
121% over limit
Discharged 27.9 mg/L against a permitted limit of 12.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2025
Nitrogen, ammonia total [as N]
246% over limit
Discharged 29.4 mg/L against a permitted limit of 8.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
E. coli
2320% over limit
Discharged 6340.36671 MPN/100mL against a permitted limit of 262 MPN/100mL (MO GEO)
DMR, Limited - Numeric Violation
E. coli
46% over limit
Discharged 6340.36671 MPN/100mL against a permitted limit of 4348 MPN/100mL (WKAV GEO)
DMR, Limited - Numeric Violation
Phosphorus, Total As P
3% over limit
Discharged 9.79089128 kg/d against a permitted limit of 9.47951992 kg/d (DPD AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
372% over limit
Discharged 24.55 mg/L against a permitted limit of 5.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, ammonia total [as N]
803% over limit
Discharged 30.7 mg/L against a permitted limit of 3.4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
494% over limit
Discharged 32.1 mg/L against a permitted limit of 5.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
Nitrogen, ammonia total [as N]
991% over limit
Discharged 37.1 mg/L against a permitted limit of 3.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
E. coli
7553% over limit
Discharged 20050 MPN/100mL against a permitted limit of 262 MPN/100mL (MO GEO)
DMR, Limited - Numeric Violation
E. coli
361% over limit
Discharged 20050 MPN/100mL against a permitted limit of 4348 MPN/100mL (WKAV GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1543% over limit
Discharged 36.15 mg/L against a permitted limit of 2.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2025
E. coli
7553% over limit
Discharged 20050 MPN/100mL against a permitted limit of 262 MPN/100mL (MO GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1591% over limit
Discharged 38.9 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
E. coli
361% over limit
Discharged 20050 MPN/100mL against a permitted limit of 4348 MPN/100mL (WKAV GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1179% over limit
Discharged 43.5 mg/L against a permitted limit of 3.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
BOD, 5-day, 20 deg. C
9% over limit
Discharged 32.7 mg/L against a permitted limit of 30 mg/L (MX WK AV)
DMR, Limited - Numeric Violation
E. coli
7553% over limit
Discharged 20050 MPN/100mL against a permitted limit of 262 MPN/100mL (MO GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
670% over limit
Discharged 30.8 mg/L against a permitted limit of 4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
64% over limit
Discharged 32.7 mg/L against a permitted limit of 20 mg/L (MO AVG)
DMR, Limited - Numeric Violation
E. coli
361% over limit
Discharged 20050 MPN/100mL against a permitted limit of 4348 MPN/100mL (WKAV GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
881% over limit
Discharged 25.5 mg/L against a permitted limit of 2.6 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
580% over limit
Discharged 37.4 mg/L against a permitted limit of 5.5 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
E. coli
1431% over limit
Discharged 4010 MPN/100mL against a permitted limit of 262 MPN/100mL (MO GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
900% over limit
Discharged 35 mg/L against a permitted limit of 3.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
Nitrogen, ammonia total [as N]
14% over limit
Discharged 14.4 mg/L against a permitted limit of 12.6 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Nitrogen, ammonia total [as N]
69% over limit
Discharged 5.73667 mg/L against a permitted limit of 3.4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
102% over limit
Discharged 10.9 mg/L against a permitted limit of 5.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2024
Nitrogen, ammonia total [as N]
259% over limit
Discharged 12.2 mg/L against a permitted limit of 3.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
323% over limit
Discharged 9.315 mg/L against a permitted limit of 2.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2024
Nitrogen, ammonia total [as N]
376% over limit
Discharged 16.2 mg/L against a permitted limit of 3.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
324% over limit
Discharged 9.76 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)