WINTHROP POTW
NPDES ID: WA0020885
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: 4 effluent violations.
Violations
April 30, 2026
BOD, 5-day, 20 deg. C
57% over limit
Discharged 47 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
11% over limit
Discharged 62 mg/L against a permitted limit of 56 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
4% over limit
Discharged 47 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
43% over limit
Discharged 67 % against a permitted limit of 77 % (MO AV MN)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, 5-day, 20 deg. C
18% over limit
Discharged 35.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, 5-day, 20 deg. C
18% over limit
Discharged 35.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Solids, total suspended
93% over limit
Discharged 108 mg/L against a permitted limit of 56 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, percent removal [total]
62% over limit
Discharged 66 % against a permitted limit of 79 % (MO AV MN)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
209% over limit
Discharged 29 % against a permitted limit of 77 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
96% over limit
Discharged 88 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
29% over limit
Discharged 108 mg/L against a permitted limit of 84 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
192% over limit
Discharged 87.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrite + Nitrate total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (Single Rdg)
DMR, Monitor Only - Overdue
Hardness, total [as CaCO3]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (Single Rdg)
DMR, Monitor Only - Overdue
Oil and grease, hexane extr method
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (Single Rdg)
DMR, Monitor Only - Overdue
Solids, total dissolved
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (Single Rdg)
DMR, Monitor Only - Overdue
Nitrogen, Kjeldahl, total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (Single Rdg)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (Single Rdg)
DMR, Monitor Only - Overdue
October 31, 2025
BOD, 5-day, 20 deg. C
38% over limit
Discharged 41.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
June 30, 2025
BOD, 5-day, 20 deg. C
7% over limit
Discharged 32 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2025
BOD, 5-day, 20 deg. C
20% over limit
Discharged 54 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
50% over limit
Discharged 45 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2025
BOD, percent removal [total]
48% over limit
Discharged 69 % against a permitted limit of 79 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
53% over limit
Discharged 69 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
128% over limit
Discharged 68.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
BOD, 5-day, 20 deg. C
32% over limit
Discharged 39.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2025
BOD, 5-day, 20 deg. C
22% over limit
Discharged 55 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
73% over limit
Discharged 52 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
Chlorine, total residual
187% over limit
Discharged 0.344667 mg/L against a permitted limit of 0.12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2024
BOD, 5-day, 20 deg. C
20% over limit
Discharged 36 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Chlorine, total residual
40% over limit
Discharged 0.168387 mg/L against a permitted limit of 0.12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2024
BOD, 5-day, 20 deg. C
38% over limit
Discharged 41.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2024
BOD, 5-day, 20 deg. C
2% over limit
Discharged 30.5 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2024
BOD, 5-day, 20 deg. C
80% over limit
Discharged 54 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
20% over limit
Discharged 54 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
13% over limit
Discharged 63.5 mg/L against a permitted limit of 56 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (24 days ago)