COLUMBIA WASTEWATER TREATMENT PLANT IMPROVEMENTS
NPDES ID: TN0056103
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: 3 effluent violations.
Violations
May 31, 2026
BOD, carbonaceous [5 day, 20 C]
6% over limit
Discharged 8.5 mg/L against a permitted limit of 8 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Nitrogen, ammonia total [as N]
191% over limit
Discharged 4.369 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
BOD, carbonaceous [5 day, 20 C]
43% over limit
Discharged 11.4 mg/L against a permitted limit of 8 mg/L (MO AVG)
DMR, Limited - Numeric Violation
SSO, Wet Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
Solids, total suspended
10% over limit
Discharged 23.1 mg/L against a permitted limit of 21 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
53% over limit
Discharged 69 mg/L against a permitted limit of 45 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
249% over limit
Discharged 5.229 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
24% over limit
Discharged 34.8 mg/L against a permitted limit of 28 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
16% over limit
Discharged 1.737 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
SSO, Wet Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrogen, ammonia total [as N]
139% over limit
Discharged 3.579 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2025
SSO, Dry Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
September 30, 2025
SSO, Wet Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
July 31, 2025
E. coli
68% over limit
Discharged 816.4 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
E. coli
26% over limit
Discharged 613.1 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
SSO, Dry Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
May 31, 2025
E. coli
26% over limit
Discharged 613.1 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
137% over limit
Discharged 2.367 mg/L against a permitted limit of 1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
18% over limit
Discharged 6.188 mg/L against a permitted limit of 5.25 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
April 30, 2025
E. coli
Limit violation
Discharged 2419.6 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
2% over limit
Discharged 10.2 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
91% over limit
Discharged 2.858 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2025
BOD, carbonaceous, percent removal
6% over limit
Discharged 36.3 % against a permitted limit of 40 % (DAILY MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
44% over limit
Discharged 11.5 mg/L against a permitted limit of 8 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, settleable
1000% over limit
Discharged 0.011 mg/L against a permitted limit of 0.001 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
121% over limit
Discharged 2344.5921803 kg/d against a permitted limit of 1060.08999109 kg/d (WKLY AVG)
DMR, Limited - Numeric Violation
SSO, Wet Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
E. coli
Limit violation
Discharged 2419.6 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
81% over limit
Discharged 50.7 mg/L against a permitted limit of 28 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
45% over limit
Discharged 58 mg/L against a permitted limit of 40 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
4% over limit
Discharged 21.8 mg/L against a permitted limit of 21 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, suspended percent removal
67% over limit
Discharged 0 % against a permitted limit of 40 % (DAILY MN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
35% over limit
Discharged 1249.9981895 kg/d against a permitted limit of 927.52199221 kg/d (WKLY AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
144% over limit
Discharged 110 mg/L against a permitted limit of 45 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
9% over limit
Discharged 1.64 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
9% over limit
Discharged 26.8 mg/L against a permitted limit of 24.5 mg/L (WKLY AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Nitrogen, ammonia total [as N]
11% over limit
Discharged 1.66 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
SSO, Dry Weather
Limit violation
Discharged 0.0329 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
SSO, Wet Weather
Limit violation
Discharged 0.0658 occur/d against a permitted limit of 0 occur/d (MO TOTAL)
DMR, Limited - Numeric Violation
January 31, 2025
E. coli
33% over limit
Discharged 648.8 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
164% over limit
Discharged 3.953 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2024
E. coli
256% over limit
Discharged 1732.9 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
18% over limit
Discharged 1.775 mg/L against a permitted limit of 1.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
E. coli
219% over limit
Discharged 1553.1 MPN/100mL against a permitted limit of 487 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2024
Nitrogen, ammonia total [as N]
27% over limit
Discharged 1.271 mg/L against a permitted limit of 1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
August 1, 2026 (5 days ago)