CINCINNATI CITY OF STP
NPDES ID: IA0070734
X — SNC: Effluent violation (non-monthly average limit)
The facility discharged more of a pollutant than its permit allows, measured over a period other than a monthly average.
This quarter: 4 effluent violations.
Violations
May 31, 2026
BOD, carbonaceous [5 day, 20 C]
52% over limit
Discharged 13.82021388 kg/d against a permitted limit of 9.07999992 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
7% over limit
Discharged 6.33268705 kg/d against a permitted limit of 5.90199995 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
April 30, 2026
BOD, carbonaceous [5 day, 20 C]
61% over limit
Discharged 14.57748588 kg/d against a permitted limit of 9.07999992 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
18% over limit
Discharged 6.9896205 kg/d against a permitted limit of 5.90199995 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
March 31, 2026
BOD, carbonaceous [5 day, 20 C]
34% over limit
Discharged 12.1920791 kg/d against a permitted limit of 9.07999992 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, ammonia total [as N]
627% over limit
Discharged 20.45391655 kg/d against a permitted limit of 2.81479998 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
7% over limit
Discharged 3.65 mg/L against a permitted limit of 3.4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
563% over limit
Discharged 5.11347914 kg/d against a permitted limit of 0.77179999 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
21% over limit
Discharged 14.6 mg/L against a permitted limit of 12.1 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.02 mg/L against a permitted limit of 2.5 mg/L (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 4.09684149 kg/d against a permitted limit of 5.90199995 kg/d (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 18 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 4 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 4 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 6.13390315 kg/d against a permitted limit of 9.07999992 kg/d (7 DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.04543632 kg/d against a permitted limit of 1.95219998 kg/d (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 1.66599839 kg/d against a permitted limit of 10.44199991 kg/d (7 DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.1 mg/L against a permitted limit of 8.4 mg/L (DAILY MX)
DMR, Limited - Overdue
pH
0% over limit
Discharged 8.05 SU against a permitted limit of 6 SU (DAILY MN)
DMR, Limited - Overdue
pH
0% over limit
Discharged 8.4 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0.00908726 kg/d against a permitted limit of 0.5902 kg/d (30DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 1.66599839 kg/d against a permitted limit of 6.80999994 kg/d (30DA AVG)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 8 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 9.2 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Overdue
November 30, 2025
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 45 mg/L (7 DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0.23286114 kg/d against a permitted limit of 5.90199995 kg/d (30DA AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 9.62 SU against a permitted limit of 6 SU (DAILY MN)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 10.44199991 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 30 mg/L (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 0.47708136 kg/d against a permitted limit of 9.07999992 kg/d (7 DA AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 kg/d against a permitted limit of 6.80999994 kg/d (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 2.3 mg/L (30DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 1.58899999 kg/d (DAILY MX)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 7 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 kg/d against a permitted limit of 0.5448 kg/d (30DA AVG)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 14 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Overdue
E. coli
0% over limit
Discharged 0 MPN/100mL against a permitted limit of 176 MPN/100mL (GEO MEAN)
DMR, Limited - Overdue
BOD, carbonaceous [5 day, 20 C]
0% over limit
Discharged 6 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Overdue
pH
0% over limit
Discharged 9.86 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Overdue
pH
0% over limit
Discharged 9.86 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
October 31, 2025
pH
0% over limit
Discharged 9.79 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2025
pH
0% over limit
Discharged 9.86 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2025
pH
0% over limit
Discharged 9.61 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
July 31, 2025
Oxygen, dissolved [DO]
16% over limit
Discharged 4.2 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
June 30, 2025
pH
0% over limit
Discharged 9.17 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
18% over limit
Discharged 4.1 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
2% over limit
Discharged 1.3225 mg/L against a permitted limit of 1.3 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Nitrogen, ammonia total [as N]
423% over limit
Discharged 36.1 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
838% over limit
Discharged 15.9475 mg/L against a permitted limit of 1.7 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.46 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
April 30, 2025
Nitrogen, ammonia total [as N]
23% over limit
Discharged 1.95944128 kg/d against a permitted limit of 1.58899999 kg/d (DAILY MX)
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
Nitrogen, ammonia total [as N]
2140% over limit
Discharged 33.6 mg/L against a permitted limit of 1.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
68% over limit
Discharged 41.875 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
81% over limit
Discharged 0.93 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.43 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
400% over limit
Discharged 34.5 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
339% over limit
Discharged 1.59311096 kg/d against a permitted limit of 0.3632 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
March 31, 2025
Nitrogen, ammonia total [as N]
487% over limit
Discharged 26.4 mg/L against a permitted limit of 4.5 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
224% over limit
Discharged 81 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
172% over limit
Discharged 27.5 mg/L against a permitted limit of 10.1 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.11 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
38% over limit
Discharged 12.55935601 kg/d against a permitted limit of 9.07999992 kg/d (7 DA AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
83% over limit
Discharged 0.84 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
25% over limit
Discharged 2.89921583 kg/d against a permitted limit of 2.31539998 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
168% over limit
Discharged 107 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
40% over limit
Discharged 1.46560506 kg/d against a permitted limit of 1.04419999 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
February 28, 2025
BOD, carbonaceous [5 day, 20 C]
143% over limit
Discharged 97 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
410% over limit
Discharged 29.6 mg/L against a permitted limit of 5.8 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
263% over limit
Discharged 90.75 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
5% over limit
Discharged 1.43351588 kg/d against a permitted limit of 1.36199999 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
115% over limit
Discharged 30.9 mg/L against a permitted limit of 14.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
92% over limit
Discharged 0.41 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
January 31, 2025
Nitrogen, ammonia total [as N]
264% over limit
Discharged 44.1 mg/L against a permitted limit of 12.1 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
171% over limit
Discharged 67.75 mg/L against a permitted limit of 25 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
85% over limit
Discharged 0.74 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
505% over limit
Discharged 31.475 mg/L against a permitted limit of 5.2 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
BOD, carbonaceous [5 day, 20 C]
83% over limit
Discharged 73 mg/L against a permitted limit of 40 mg/L (7 DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
28% over limit
Discharged 1.50867513 kg/d against a permitted limit of 1.18039999 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
December 31, 2024
pH
0% over limit
Discharged 9.85 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
286% over limit
Discharged 15.448 mg/L against a permitted limit of 4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
45% over limit
Discharged 1.31872062 kg/d against a permitted limit of 0.90799999 kg/d (30DA AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
86% over limit
Discharged 0.71 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
231% over limit
Discharged 27.8 mg/L against a permitted limit of 8.4 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
78% over limit
Discharged 3.47360663 kg/d against a permitted limit of 1.95219998 kg/d (DAILY MX)
DMR, Limited - Numeric Violation
November 30, 2024
Nitrogen, ammonia total [as N]
88% over limit
Discharged 13 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.14 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
165% over limit
Discharged 8.9975 mg/L against a permitted limit of 3.4 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
38% over limit
Discharged 3.1 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
October 31, 2024
pH
0% over limit
Discharged 10.14 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
142% over limit
Discharged 6.77 mg/L against a permitted limit of 2.8 mg/L (30DA AVG)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
79% over limit
Discharged 1.07 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
Nitrogen, ammonia total [as N]
48% over limit
Discharged 10.2 mg/L against a permitted limit of 6.9 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Oxygen, dissolved [DO]
2% over limit
Discharged 4.9 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
pH
0% over limit
Discharged 9.92 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2024
pH
0% over limit
Discharged 9.44 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Numeric Violation
Oxygen, dissolved [DO]
28% over limit
Discharged 3.6 mg/L against a permitted limit of 5 mg/L (DAILY MN)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (4 months ago)
Last confirmed
August 15, 2026 (10 hours ago)