Is Mequon Water Utility Tap Water Safe? Quality Report

Water source: SWP
Ownership: Local government
Counties served: Ozaukee

Compliance record

Formal violations the EPA has on file for this supplier. A health-based violation means a contaminant limit or a required treatment was breached; the rest are monitoring or reporting failures — still violations, but not a measured health risk.

health-based violations

violations on file

still open

Violation	Type	Status	Period
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31
MCL	Health-based	Resolved	2010-01-01 → 2010-12-31

Other contaminants detected

Each bar shows the measured level as a share of the EPA limit: green is well under, amber is close to it, red is over. For lead and copper the limit applies to exactly the 90th-percentile figure shown, so red there means a real exceedance. For everything else the limit applies to a running annual average while the figure is the 95th percentile of this system's samples — over 100% is worth reading, but is not by itself a violation. Where a single sample came in higher than that percentile, it is noted under the bar. Formal violations are listed separately.

Contaminant	Level vs EPA limit	Detection rate	Source	Period
Copper	136 µg/L 10% of the EPA limit 1300 µg/L worst single sample: 240 µg/L	49/50	SYR4	2014–2017
Bromodichloromethane	4.715 µg/L No EPA limit set worst single sample: 5.8 µg/L	40/40	SYR4	2012–2019
Chloroform	6.225 µg/L No EPA limit set worst single sample: 8.5 µg/L	40/40	SYR4	2012–2019
Dibromochloromethane	2.915 µg/L No EPA limit set worst single sample: 3.2 µg/L	40/40	SYR4	2012–2019
TTHM	14.0275 µg/L 18% of the EPA limit 80 µg/L worst single sample: 17.5 µg/L	40/40	SYR4	2012–2019
Total Haloacetic Acids (HAA5)	5.299 µg/L 8.8% of the EPA limit 60 µg/L worst single sample: 5.66 µg/L	38/40	SYR4	2012–2019
Lead	4.2 µg/L 28% of the EPA limit 15 µg/L worst single sample: 21 µg/L	31/50	SYR4	2014–2017
Trichloroacetic Acid	1.555 µg/L No EPA limit set worst single sample: 1.7 µg/L	30/40	SYR4	2012–2019
Dichloroacetic Acid	2.97 µg/L No EPA limit set worst single sample: 3.2 µg/L	27/40	SYR4	2012–2019
Dibromoacetic Acid	0.7040 µg/L No EPA limit set worst single sample: 0.8100 µg/L	25/40	SYR4	2012–2019
Lead	0.00052 mg/L 3.5% of the EPA limit 0.0150 mg/L	14/14	LCR	2023
Monobromoacetic Acid	0.5360 µg/L No EPA limit set worst single sample: 0.5500 µg/L	8/40	SYR4	2012–2019

2 contaminants tested, none detected

BromoformMonochloroacetic Acid

Utility contact

Frequently asked questions about Mequon Water Utility

Is Mequon Water Utility tap water safe to drink?

EPA monitoring detected 12 contaminants in Mequon Water Utility's water. A detection isn't the same as a violation — most levels are within federal limits. See each level and source above, and the utility's annual Consumer Confidence Report for its official compliance status.

What contaminants were detected in Mequon Water Utility's water?

EPA monitoring detected Copper, Bromodichloromethane, Chloroform, Dibromochloromethane, TTHM, and others. The full list with the level and data source for each is above.

How many people does Mequon Water Utility serve?

Mequon Water Utility reports serving 11,152 people in Wisconsin, per its EPA record.

Has Mequon Water Utility had any water quality violations?

The EPA has 88 violations on file for Mequon Water Utility, of which 24 are health-based (a contaminant limit or required treatment was breached) and 0 remain open. The rest are monitoring or reporting failures.

Where does this data come from?

Every figure is official EPA drinking-water monitoring — the Lead & Copper Rule, the UCMR-5 nationwide testing program, and the EPA Six-Year Review — not our own testing. Each number is labelled with its source and period.