MAYVILLE WASTEWATER TREATMENT FACILITY
NPDES ID: WI0024643
D — SNC: Discharge monitoring report not received
The facility didn't submit its required discharge monitoring report.
This quarter: 20 reporting violations.
Violations
April 30, 2026
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 4.4 mg/L (WKLY AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 21 mg/L (MO AVG)
DMR, Limited - Overdue
Phosphorus, total [as P]
0% over limit
Discharged 0 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 0 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (MO MAX)
DMR, Monitor Only - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 21 mg/L (WKLY AVG)
DMR, Limited - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 6 SU (DAILY MN)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Overdue
Chloride [as Cl]
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Chloride [as Cl]
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO MAX)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
March 31, 2026
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
February 28, 2026
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 21 mg/L (WKLY AVG)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 9 SU (DAILY MX)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 3.1 mg/L (MO AVG)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, ammonia total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 4.4 mg/L (WKLY AVG)
DMR, Limited - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
pH
0% over limit
Discharged 0 SU against a permitted limit of 6 SU (DAILY MN)
DMR, Limited - Overdue
Solids, total suspended
0% over limit
Discharged 0 mg/L against a permitted limit of 21 mg/L (MO AVG)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
BOD, 5-day, 20 deg. C
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Chloride [as Cl]
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0 MGD against a permitted limit of 0 MGD (MO MAX)
DMR, Monitor Only - Overdue
Chloride [as Cl]
0% over limit
Discharged 0 kg/d against a permitted limit of 0 kg/d (MO MAX)
DMR, Monitor Only - Overdue
Oxygen, dissolved [DO]
0% over limit
Discharged 0 mg/L against a permitted limit of 6 mg/L (DAILY MN)
DMR, Limited - Overdue
Phosphorus, total [as P]
0% over limit
Discharged 0 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Overdue
January 31, 2026
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Phosphorus, total [as P]
17% over limit
Discharged 1.03720839 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
5% over limit
Discharged 0.93283379 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
November 30, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
October 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Phosphorus, total [as P]
15% over limit
Discharged 1.02213559 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (QRTR MAX)
DMR, Monitor Only - Overdue
Nitrite + Nitrate total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (QRTR MAX)
DMR, Monitor Only - Overdue
Nitrogen, Kjeldahl, total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (QRTR MAX)
DMR, Monitor Only - Overdue
August 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
39% over limit
Discharged 1.23410819 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
July 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
June 30, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
May 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
April 30, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
March 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
2% over limit
Discharged 0.90990679 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
19% over limit
Discharged 1.05859179 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
January 31, 2025
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (MO MAX)
DMR, Monitor Only - Overdue
Mercury, total recoverable
0% over limit
Discharged 0 mg/L against a permitted limit of 0.0000045 mg/L (DAILY MX)
DMR, Limited - Overdue
Phosphorus, total [as P]
14% over limit
Discharged 1.01664219 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
December 31, 2024
Nitrogen, total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (QRTR MAX)
DMR, Monitor Only - Overdue
Nitrogen, Kjeldahl, total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (QRTR MAX)
DMR, Monitor Only - Overdue
Nitrite + Nitrate total [as N]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (QRTR MAX)
DMR, Monitor Only - Overdue
November 30, 2024
Phosphorus, total [as P]
10% over limit
Discharged 0.97836999 kg/d against a permitted limit of 0.88983999 kg/d (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (23 days ago)