IRON MOUNTAIN LAKE WWTF
NPDES ID: MO0122581
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: 6 effluent violations.
Violations
May 31, 2026
Nitrogen, ammonia total [as N]
339% over limit
Discharged 29 mg/L against a permitted limit of 6.6 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
134% over limit
Discharged 29 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2026
E. coli
415% over limit
Discharged 649 MPN/100mL against a permitted limit of 126 MPN/100mL (30DA GM)
DMR, Limited - Numeric Violation
E. coli
3% over limit
Discharged 649 MPN/100mL against a permitted limit of 630 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
222% over limit
Discharged 26.1 mg/L against a permitted limit of 8.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
110% over limit
Discharged 26.1 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, 5-day, percent removal
7% over limit
Discharged 84 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
237% over limit
Discharged 31.3 mg/L against a permitted limit of 9.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
152% over limit
Discharged 31.3 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
Nitrogen, ammonia total [as N]
50% over limit
Discharged 15.4 mg/L against a permitted limit of 10.3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
93% over limit
Discharged 57.8 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
73% over limit
Discharged 74 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
90% over limit
Discharged 15.4 mg/L against a permitted limit of 8.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
28% over limit
Discharged 57.8 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
January 31, 2026
BOD, 5-day, percent removal
27% over limit
Discharged 81 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
November 30, 2025
BOD, 5-day, 20 deg. C
40% over limit
Discharged 42 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
259% over limit
Discharged 44.5 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
378% over limit
Discharged 44.5 mg/L against a permitted limit of 9.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
27% over limit
Discharged 81 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
October 31, 2025
E. coli
37% over limit
Discharged 172 MPN/100mL against a permitted limit of 126 MPN/100mL (30DA GM)
DMR, Limited - Numeric Violation
September 30, 2025
E. coli
74% over limit
Discharged 219 MPN/100mL against a permitted limit of 126 MPN/100mL (30DA GM)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
79% over limit
Discharged 9.31 mg/L against a permitted limit of 5.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2025
E. coli
90% over limit
Discharged 1200 MPN/100mL against a permitted limit of 630 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
E. coli
852% over limit
Discharged 1200 MPN/100mL against a permitted limit of 126 MPN/100mL (30DA GM)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
697% over limit
Discharged 30.3 mg/L against a permitted limit of 3.8 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
194% over limit
Discharged 30.3 mg/L against a permitted limit of 10.3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2025
Nitrogen, ammonia total [as N]
138% over limit
Discharged 29.5 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
586% over limit
Discharged 29.5 mg/L against a permitted limit of 4.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
June 30, 2025
Nitrogen, ammonia total [as N]
361% over limit
Discharged 23.5 mg/L against a permitted limit of 5.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
90% over limit
Discharged 23.5 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
286% over limit
Discharged 25.5 mg/L against a permitted limit of 6.6 mg/L (MO AVG)
DMR, Limited - Numeric Violation
E. coli
631% over limit
Discharged 921 MPN/100mL against a permitted limit of 126 MPN/100mL (30DA GM)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
53% over limit
Discharged 77 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
106% over limit
Discharged 25.5 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
E. coli
46% over limit
Discharged 921 MPN/100mL against a permitted limit of 630 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
April 30, 2025
Nitrogen, ammonia total [as N]
80% over limit
Discharged 22.3 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
175% over limit
Discharged 22.3 mg/L against a permitted limit of 8.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2025
BOD, 5-day, 20 deg. C
56% over limit
Discharged 70.3 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
253% over limit
Discharged 47 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
101% over limit
Discharged 24.9 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
168% over limit
Discharged 24.9 mg/L against a permitted limit of 9.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
134% over limit
Discharged 70.3 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Solids, suspended percent removal
40% over limit
Discharged 79 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
189% over limit
Discharged 23.4 mg/L against a permitted limit of 8.1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
127% over limit
Discharged 23.4 mg/L against a permitted limit of 10.3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2025
Nitrogen, ammonia total [as N]
88% over limit
Discharged 23.3 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
151% over limit
Discharged 23.3 mg/L against a permitted limit of 9.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2024
Nitrogen, ammonia total [as N]
104% over limit
Discharged 25.3 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
187% over limit
Discharged 57 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
172% over limit
Discharged 25.3 mg/L against a permitted limit of 9.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
12% over limit
Discharged 33.6 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
Solids, total suspended
42% over limit
Discharged 64 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
274% over limit
Discharged 34.8 mg/L against a permitted limit of 9.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
113% over limit
Discharged 64 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
133% over limit
Discharged 65 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
180% over limit
Discharged 58 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
30% over limit
Discharged 39.1 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
181% over limit
Discharged 34.8 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2024
Nitrogen, ammonia total [as N]
103% over limit
Discharged 25.2 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
E. coli
Limit violation
Discharged 242025.2 MPN/100mL against a permitted limit of 126 MPN/100mL (30DA GM)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
241% over limit
Discharged 25.2 mg/L against a permitted limit of 7.4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
31% over limit
Discharged 59.1 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
153% over limit
Discharged 62 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
E. coli
Limit violation
Discharged 2420 MPN/100mL against a permitted limit of 630 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
97% over limit
Discharged 59.1 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2024
Nitrogen, ammonia total [as N]
113% over limit
Discharged 26.4 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
58% over limit
Discharged 47.4 mg/L against a permitted limit of 30 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
408% over limit
Discharged 26.4 mg/L against a permitted limit of 5.2 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
5% over limit
Discharged 47.4 mg/L against a permitted limit of 45 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, percent removal
33% over limit
Discharged 80 % against a permitted limit of 85 % (MO AV MN)
DMR, Limited - Numeric Violation
August 31, 2024
Nitrogen, ammonia total [as N]
153% over limit
Discharged 26.1 mg/L against a permitted limit of 10.3 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
587% over limit
Discharged 26.1 mg/L against a permitted limit of 3.8 mg/L (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2024
Nitrogen, ammonia total [as N]
146% over limit
Discharged 30.5 mg/L against a permitted limit of 12.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
609% over limit
Discharged 30.5 mg/L against a permitted limit of 4.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)