MCELVAIN SCHOOL STP
NPDES ID: IL0050083
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.
Violations
April 30, 2026
Solids, total suspended
17% over limit
Discharged 14 mg/L against a permitted limit of 12 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
60% over limit
Discharged 16 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, carbonaceous [5 day, 20 C]
42% over limit
Discharged 14.2 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2026
BOD, carbonaceous [5 day, 20 C]
41% over limit
Discharged 14.1 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Coliform, fecal general
505% over limit
Discharged 2420 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
60% over limit
Discharged 2.4 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Coliform, fecal general
197% over limit
Discharged 1187 MPN/100mL against a permitted limit of 400 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
60% over limit
Discharged 2.4 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2024
Nitrogen, ammonia total [as N]
77% over limit
Discharged 5.3 mg/L against a permitted limit of 3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (24 days ago)