FLAT ROCK TERRACE MHP
NPDES ID: MI0029122
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: 14 effluent violations.
Violations
June 30, 2026
Nitrogen, ammonia total [as N]
132% over limit
Discharged 0.105328 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
524% over limit
Discharged 3.12 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
176% over limit
Discharged 27.6 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
28% over limit
Discharged 0.46308 kg/d against a permitted limit of 0.3632 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
255% over limit
Discharged 14.2 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
151% over limit
Discharged 5.02 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
May 31, 2026
BOD, carbonaceous [5 day, 20 C]
13% over limit
Discharged 1.08051999 kg/d against a permitted limit of 0.95339999 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
300% over limit
Discharged 16 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
90% over limit
Discharged 0.69007999 kg/d against a permitted limit of 0.3632 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
204% over limit
Discharged 30.4 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
105% over limit
Discharged 4.1 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
556% over limit
Discharged 3.28 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
5% over limit
Discharged 210 MPN/100mL against a permitted limit of 200 MPN/100mL (MO GEOMN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
214% over limit
Discharged 0.142556 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Oxygen, dissolved [DO]
2% over limit
Discharged 5.9 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
December 31, 2025
BOD, carbonaceous [5 day, 20 C]
32% over limit
Discharged 41 mg/L against a permitted limit of 31 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
61% over limit
Discharged 16.1 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
8% over limit
Discharged 22.7 mg/L against a permitted limit of 21 mg/L (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Nitrogen, ammonia total [as N]
1268% over limit
Discharged 6.84 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
247% over limit
Discharged 0.63060599 kg/d against a permitted limit of 0.1816 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
49% over limit
Discharged 0.54026 kg/d against a permitted limit of 0.3632 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
87% over limit
Discharged 1.77967999 kg/d against a permitted limit of 0.95339999 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
1835% over limit
Discharged 38.7 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
349% over limit
Discharged 0.203846 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
330% over limit
Discharged 43 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
290% over limit
Discharged 15.6 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
12% over limit
Discharged 447 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
September 30, 2025
Phosphorus, total [as P]
7% over limit
Discharged 1.07 mg/L against a permitted limit of 1 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
658% over limit
Discharged 3.79 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
196% over limit
Discharged 0.134384 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Coliform, fecal general
11% over limit
Discharged 222 MPN/100mL against a permitted limit of 200 MPN/100mL (MO GEOMN)
DMR, Limited - Numeric Violation
Coliform, fecal general
Limit violation
Discharged 240 MPN/100mL against a permitted limit of 400 MPN/100mL (7 DA GEO)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
160% over limit
Discharged 26 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
280% over limit
Discharged 0.69007999 kg/d against a permitted limit of 0.1816 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
150% over limit
Discharged 10 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
334% over limit
Discharged 8.68 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
33% over limit
Discharged 4 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Solids, total suspended
17% over limit
Discharged 35 mg/L against a permitted limit of 30 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
August 31, 2025
Nitrogen, ammonia total [as N]
222% over limit
Discharged 1.61 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
58% over limit
Discharged 6.3 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
68% over limit
Discharged 0.076272 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2025
Nitrogen, ammonia total [as N]
252% over limit
Discharged 1.76 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
95% over limit
Discharged 7.8 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
28% over limit
Discharged 12.8 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
42% over limit
Discharged 2.84 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
78% over limit
Discharged 0.080812 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
June 30, 2025
BOD, carbonaceous [5 day, 20 C]
25% over limit
Discharged 5 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
34% over limit
Discharged 13.4 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
214% over limit
Discharged 1.57 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
86% over limit
Discharged 0.084444 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
59% over limit
Discharged 3.18 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
127% over limit
Discharged 0.103058 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
292% over limit
Discharged 1.96 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
36% over limit
Discharged 13.6 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
75% over limit
Discharged 7 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
14% over limit
Discharged 0.20657 kg/d against a permitted limit of 0.1816 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
November 30, 2024
BOD, carbonaceous [5 day, 20 C]
3% over limit
Discharged 10.3 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
80% over limit
Discharged 7.2 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
7% over limit
Discharged 0.048578 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
184% over limit
Discharged 1.42 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
October 31, 2024
BOD, carbonaceous [5 day, 20 C]
103% over limit
Discharged 8.1 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
240% over limit
Discharged 1.7 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
32% over limit
Discharged 0.059928 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
22% over limit
Discharged 2.44 mg/L against a permitted limit of 2 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
BOD, carbonaceous [5 day, 20 C]
115% over limit
Discharged 8.6 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
14% over limit
Discharged 11.4 mg/L against a permitted limit of 10 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
210% over limit
Discharged 1.55 mg/L against a permitted limit of 0.5 mg/L (MO AVG)
DMR, Limited - Numeric Violation
August 31, 2024
Nitrogen, ammonia total [as N]
206% over limit
Discharged 1.53 mg/L against a permitted limit of 0.5 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 (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
108% over limit
Discharged 8.3 mg/L against a permitted limit of 4 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
12% over limit
Discharged 0.050848 kg/d against a permitted limit of 0.0454 kg/d (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 15, 2026 (9 hours ago)