YONCALLA STP
NPDES ID: OR0022454
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
This quarter: 2 effluent violations, 1 reporting violation.
Violations
April 30, 2026
Solids, suspended percent removal
12% over limit
Discharged 60.9 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
65% over limit
Discharged 75.2 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, 5-day, percent removal
83% over limit
Discharged 72.6 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Alkalinity, total [as CaCO3]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
BOD, 5-day, 20 deg. C
1% over limit
Discharged 30.4 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.1 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, 5-day, percent removal
37% over limit
Discharged 79.5 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
January 31, 2026
E. coli
496% over limit
Discharged 2420 MPN/100mL against a permitted limit of 406 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2025
pH
0% over limit
Discharged 6.1 SU against a permitted limit of 6.3 SU (DAILY MN)
DMR, Limited - Numeric Violation
Solids, total suspended
95% over limit
Discharged 97.4 mg/L against a permitted limit of 50 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Flow, in conduit or thru treatment plant
Limit violation
Discharged 0.466 MGD against a permitted limit of 0 MGD (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2025
BOD, 5-day, percent removal
19% over limit
Discharged 82.1 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
March 31, 2025
BOD, 5-day, percent removal
75% over limit
Discharged 73.8 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
February 28, 2025
BOD, 5-day, percent removal
288% over limit
Discharged 41.8 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
14% over limit
Discharged 60 % against a permitted limit of 65 % (MO AV MN)
DMR, Limited - Numeric Violation
January 31, 2025
E. coli
0% over limit
Discharged 0 MPN/100mL against a permitted limit of 0 MPN/100mL (DAILY MX)
DMR, Monitor Only - Overdue
BOD, 5-day, percent removal
29% over limit
Discharged 80.7 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
E. coli
27% over limit
Discharged 517 MPN/100mL against a permitted limit of 406 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
E. coli
0% over limit
Discharged 0 MPN/100mL against a permitted limit of 126 MPN/100mL (MO GEO)
DMR, Limited - Overdue
December 31, 2024
BOD, 5-day, percent removal
22% over limit
Discharged 81.7 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
November 30, 2024
BOD, 5-day, percent removal
104% over limit
Discharged 69.4 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 15, 2026 (3 hours ago)