SHERIDAN STP
NPDES ID: OR0020648
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: 1 effluent violation.
Violations
April 30, 2026
Nitrogen, ammonia total [as N]
39% over limit
Discharged 4.3 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, 5-day, 20 deg. C
1% over limit
Discharged 372.73399687 kg/d against a permitted limit of 367.73999691 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
23% over limit
Discharged 36.9 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
32% over limit
Discharged 4.1 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
103% over limit
Discharged 6.3 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
11% over limit
Discharged 8.9 mg/L against a permitted limit of 8 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrogen, ammonia total [as N]
39% over limit
Discharged 4.3 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
32% over limit
Discharged 4.1 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2025
Nitrogen, ammonia total [as N]
74% over limit
Discharged 5.4 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Solids, total suspended
30% over limit
Discharged 65 mg/L against a permitted limit of 50 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2025
Chlorine usage
0% over limit
Discharged 14.18749988 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 269.67599773 kg/d against a permitted limit of 1225.7999897 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 177.05999851 kg/d against a permitted limit of 590.19999504 kg/d (MO AVG)
DMR, Limited - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 9.5 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 41 mg/L against a permitted limit of 50 mg/L (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 269.67599773 kg/d against a permitted limit of 907.99999237 kg/d (WKLY AVG)
DMR, Limited - Overdue
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)