TERRACE HILL SANITARY DISTRICT STP
NPDES ID: IA0062472
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
May 31, 2026
Nitrogen, ammonia total [as N]
100% over limit
Discharged 7.985 mg/L against a permitted limit of 4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
100% over limit
Discharged 7.985 mg/L against a permitted limit of 4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrogen, ammonia total [as N]
250% over limit
Discharged 14 mg/L against a permitted limit of 4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Solids, total suspended
3% over limit
Discharged 82 mg/L against a permitted limit of 80 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
90% over limit
Discharged 76 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
204% over limit
Discharged 76 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
250% over limit
Discharged 14 mg/L against a permitted limit of 4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
293% over limit
Discharged 11 mg/L against a permitted limit of 2.8 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.45774859 kg/d against a permitted limit of 1.45279999 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
293% over limit
Discharged 11 mg/L against a permitted limit of 2.8 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
0% over limit
Discharged 1.45774859 kg/d against a permitted limit of 1.45279999 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
E. coli
242% over limit
Discharged 430.5032 MPN/100mL against a permitted limit of 126 MPN/100mL (GEO MEAN)
DMR, Limited - Numeric Violation
December 31, 2024
Nitrogen, ammonia total [as N]
159% over limit
Discharged 14 mg/L against a permitted limit of 5.4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
52% over limit
Discharged 38 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
159% over limit
Discharged 14 mg/L against a permitted limit of 5.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2024
Nitrogen, ammonia total [as N]
147% over limit
Discharged 9.6401 mg/L against a permitted limit of 3.9 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
147% over limit
Discharged 9.6401 mg/L against a permitted limit of 3.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)