COLTON STP
NPDES ID: WA0023175
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
April 30, 2026
Solids, total suspended
43% over limit
Discharged 64.5667 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
13% over limit
Discharged 50.7333 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
12% over limit
Discharged 73 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, percent removal [total]
60% over limit
Discharged 44 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 8.99 SU against a permitted limit of 8.5 SU (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
0% over limit
Discharged 21.39552162 kg/d against a permitted limit of 21.33799982 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
163% over limit
Discharged 8 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
March 31, 2026
Solids, total suspended
11% over limit
Discharged 72 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
1% over limit
Discharged 45.525 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
38% over limit
Discharged 62 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
1% over limit
Discharged 21.56499982 kg/d against a permitted limit of 21.33799982 kg/d (MO AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.07 SU against a permitted limit of 8.5 SU (DAILY MX)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
114% over limit
Discharged 25 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, percent removal [total]
49% over limit
Discharged 48 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
February 28, 2026
Solids, total suspended
136% over limit
Discharged 106 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
63% over limit
Discharged 106 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
11% over limit
Discharged 34.35871971 kg/d against a permitted limit of 30.87199974 kg/d (WKLY AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.12 SU against a permitted limit of 8.5 SU (DAILY MX)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
137% over limit
Discharged 17 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, percent removal [total]
3% over limit
Discharged 64 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
12% over limit
Discharged 50.6 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
61% over limit
Discharged 34.35871971 kg/d against a permitted limit of 21.33799982 kg/d (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2026
BOD, 5-day, 20 deg. C
23% over limit
Discharged 55.425 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, percent removal [total]
3% over limit
Discharged 64 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
11% over limit
Discharged 72 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
10% over limit
Discharged 220 MPN/100mL against a permitted limit of 200 MPN/100mL (MAXIMUM)
DMR, Limited - Numeric Violation
Solids, total suspended
15% over limit
Discharged 75 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.18 SU against a permitted limit of 8.5 SU (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2025
Solids, suspended percent removal
63% over limit
Discharged 43 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
22% over limit
Discharged 55 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
22% over limit
Discharged 79 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, percent removal [total]
71% over limit
Discharged 40 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
Solids, total suspended
37% over limit
Discharged 61.6667 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
29% over limit
Discharged 84 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 8.81 SU against a permitted limit of 8.5 SU (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2025
BOD, percent removal [total]
31% over limit
Discharged 54 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
Solids, total suspended
32% over limit
Discharged 59.5 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
131% over limit
Discharged 19 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
Solids, total suspended
2% over limit
Discharged 66 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Coliform, fecal general
136% over limit
Discharged 236.485 MPN/100mL against a permitted limit of 100 MPN/100mL (MO GEOMN)
DMR, Limited - Numeric Violation
Coliform, fecal general
82% over limit
Discharged 363 MPN/100mL against a permitted limit of 200 MPN/100mL (MAXIMUM)
DMR, Limited - Numeric Violation
December 31, 2024
pH
0% over limit
Discharged 8.62 SU against a permitted limit of 8.5 SU (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
42% over limit
Discharged 64 mg/L against a permitted limit of 45 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
28% over limit
Discharged 83 mg/L against a permitted limit of 65 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
November 30, 2024
BOD, percent removal [total]
0% over limit
Discharged 0 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Overdue
October 31, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
BOD, percent removal [total]
0% over limit
Discharged 0 % against a permitted limit of 0 % (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (WKLY AVG)
DMR, Monitor Only - Overdue
September 30, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
BOD, percent removal [total]
0% over limit
Discharged 0 % against a permitted limit of 0 % (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (WKLY AVG)
DMR, Monitor Only - Overdue
August 31, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (WKLY AVG)
DMR, Monitor Only - Overdue
BOD, percent removal [total]
0% over limit
Discharged 0 % against a permitted limit of 0 % (MO AVG)
DMR, Monitor Only - Overdue
July 31, 2024
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (WKLY AVG)
DMR, Monitor Only - Overdue
BOD, percent removal [total]
0% over limit
Discharged 0 % against a permitted limit of 0 % (MO AVG)
DMR, Monitor Only - Overdue
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)