PRAIRIE ISLAND
NPDES ID: MN0061336
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: 2 effluent violations, 4 single-event violations, 2 reporting violations.
Violations
June 30, 2026
Solids, suspended percent removal
73% over limit
Discharged 74 % against a permitted limit of 85 % (MN % RMV)
DMR, Limited - Numeric Violation
May 31, 2026
Solids, suspended percent removal
13% over limit
Discharged 83 % against a permitted limit of 85 % (MN % RMV)
DMR, Limited - Numeric Violation
March 31, 2026
Solids, suspended percent removal
93% over limit
Discharged 71 % against a permitted limit of 85 % (MN % RMV)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
July 31, 2025
Solids, suspended percent removal
80% over limit
Discharged 73 % against a permitted limit of 85 % (MN % RMV)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (5 months ago)
Last confirmed
September 15, 2026 (4 days ago)