MAMMOTH SPRING WWTP
NPDES ID: AR0023850
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: 19 effluent violations.
Violations
June 30, 2026
BOD, carbonaceous [5 day, 20 C]
5% over limit
Discharged 15.8 mg/L against a permitted limit of 15 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
58% over limit
Discharged 15.8 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 1876 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
134% over limit
Discharged 24.6 mg/L against a permitted limit of 10.5 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 2000 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
237% over limit
Discharged 23.6 mg/L against a permitted limit of 7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2026
Nitrogen, ammonia total [as N]
216% over limit
Discharged 22.1 mg/L against a permitted limit of 7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 2000 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
51% over limit
Discharged 22.6 mg/L against a permitted limit of 15 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 2000 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
69% over limit
Discharged 16.9 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
130% over limit
Discharged 24.2 mg/L against a permitted limit of 10.5 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Nitrogen, ammonia total [as N]
75% over limit
Discharged 3.88623997 kg/d against a permitted limit of 2.22459998 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
21% over limit
Discharged 12.1 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
10% over limit
Discharged 6.69 mg/L against a permitted limit of 7.4 mg/L (INST MIN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
631% over limit
Discharged 28.5 mg/L against a permitted limit of 3.9 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
392% over limit
Discharged 19.2 mg/L against a permitted limit of 3.9 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
310% over limit
Discharged 1640 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Coliform, fecal general
458% over limit
Discharged 1116 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
March 31, 2026
Solids, total suspended
20% over limit
Discharged 18 mg/L against a permitted limit of 15 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
28% over limit
Discharged 12.8 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
30% over limit
Discharged 30 mg/L against a permitted limit of 23 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
10% over limit
Discharged 440 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
31% over limit
Discharged 13.5 mg/L against a permitted limit of 10.3 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Coliform, fecal general
Limit violation
Discharged 699 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
3% over limit
Discharged 7.15 mg/L against a permitted limit of 7.4 mg/L (INST MIN)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 2000 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
3% over limit
Discharged 10.3 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
18% over limit
Discharged 12.2 mg/L against a permitted limit of 10.3 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Coliform, fecal general
4% over limit
Discharged 207 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
Coliform, fecal general
106% over limit
Discharged 824 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
September 30, 2025
Coliform, fecal general
10% over limit
Discharged 219 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
December 31, 2024
Solids, total suspended
29% over limit
Discharged 10.97771991 kg/d against a permitted limit of 8.53519993 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
104% over limit
Discharged 47 mg/L against a permitted limit of 23 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Solids, total suspended
67% over limit
Discharged 25 mg/L against a permitted limit of 15 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2024
Solids, total suspended
9% over limit
Discharged 9.27521992 kg/d against a permitted limit of 8.53519993 kg/d (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2024
Nitrogen, ammonia total [as N]
102% over limit
Discharged 21.2 mg/L against a permitted limit of 10.5 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
97% over limit
Discharged 13.8 mg/L against a permitted limit of 7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
3% over limit
Discharged 412 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
September 30, 2024
Coliform, fecal general
Limit violation
Discharged 2000 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 1030 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
32% over limit
Discharged 13.9 mg/L against a permitted limit of 10.5 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
53% over limit
Discharged 10.7 mg/L against a permitted limit of 7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2024
Coliform, fecal general
216% over limit
Discharged 1264 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
Coliform, fecal general
286% over limit
Discharged 772 MPN/100mL against a permitted limit of 200 MPN/100mL (30DA GEO)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
75% over limit
Discharged 1.23 mg/L against a permitted limit of 5 mg/L (INST MIN)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
3% over limit
Discharged 10.3 mg/L against a permitted limit of 10 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
92% over limit
Discharged 20.2 mg/L against a permitted limit of 10.5 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
99% over limit
Discharged 13.9 mg/L against a permitted limit of 7 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 15, 2026 (6 hours ago)