Is Jefferson Waterworks Tap Water Safe? Quality Report

Water source: Ground water
Ownership: Local government
Counties served: Jefferson

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	Archived	2024-04-01 → 2024-06-30
MCL	Health-based	Archived	2024-04-01 → 2024-06-30
MCL	Health-based	Archived	2024-04-01 → 2024-06-30
MCL	Health-based	Archived	2024-04-01 → 2024-06-30
MCL	Health-based	Archived	2024-04-01 → 2024-06-30
MCL	Health-based	Archived	2024-01-01 → 2024-03-31
MCL	Health-based	Archived	2024-01-01 → 2024-03-31
MCL	Health-based	Archived	2024-01-01 → 2024-03-31
MCL	Health-based	Archived	2024-01-01 → 2024-03-31
MCL	Health-based	Archived	2024-01-01 → 2024-03-31

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
Fluoride	1058 µg/L 26% of the EPA limit 4000 µg/L worst single sample: 1270 µg/L	103/200	SYR4	2012–2019
Copper	327.8 µg/L 25% of the EPA limit 1300 µg/L worst single sample: 920 µg/L	35/40	SYR4	2014–2017
Combined Radium (-226 And -228)	5.94 pCi/L 119% of the EPA limit, at the 95th percentile of samples — 5 pCi/L worst single sample: 5.98 pCi/L	28/28	SYR4	2012–2019
Lead	17.992 µg/L 120% of the EPA limit, at the 95th percentile of samples — 15 µg/L worst single sample: 46.5 µg/L	23/40	SYR4	2014–2017
Combined Uranium	1.66983 µg/L 5.6% of the EPA limit 30 µg/L worst single sample: 1.74667 µg/L	22/22	SYR4	2012–2017
Lead	0.0035 mg/L 23% of the EPA limit 0.0150 mg/L	19/19	LCR	2024
Bromoform	6.265 µg/L No EPA limit set worst single sample: 8.9 µg/L	18/25	SYR4	2013–2019
Dibromochloromethane	5.655 µg/L No EPA limit set worst single sample: 7.1 µg/L	18/27	SYR4	2013–2019
Gross Alpha, Excl. Radon And U	21.51 pCi/L 143% of the EPA limit, at the 95th percentile of samples — 15 pCi/L worst single sample: 22.7 pCi/L	18/18	SYR4	2012–2017
Bromodichloromethane	3.11 µg/L No EPA limit set worst single sample: 3.2 µg/L	10/21	SYR4	2013–2019
TTHM	17.726 µg/L 22% of the EPA limit 80 µg/L worst single sample: 20.3 µg/L	10/11	SYR4	2013–2019
Chloroform	1.82 µg/L No EPA limit set worst single sample: 1.9 µg/L	9/17	SYR4	2013–2019
Gross Beta Particle Activity	10.844 pCi/L No EPA limit set worst single sample: 12.2 pCi/L	9/9	SYR4	2012–2014
Barium	151.95 µg/L 7.6% of the EPA limit 2000 µg/L worst single sample: 153 µg/L	8/8	SYR4	2014–2017
Dibromoacetic Acid	1.675 µg/L No EPA limit set worst single sample: 1.7 µg/L	6/11	SYR4	2013–2019
Nitrate	1070 µg/L 11% of the EPA limit 10000 µg/L	6/36	SYR4	2014–2019
Total Haloacetic Acids (HAA5)	2.925 µg/L 4.9% of the EPA limit 60 µg/L worst single sample: 2.98 µg/L	6/11	SYR4	2013–2019
Monobromoacetic Acid	0.6005 µg/L No EPA limit set worst single sample: 0.6200 µg/L	4/11	SYR4	2013–2019
Dichloroacetic Acid	0.7910 µg/L No EPA limit set worst single sample: 0.8200 µg/L	3/11	SYR4	2013–2019
Nitrate-Nitrite	1045 µg/L 10% of the EPA limit 10000 µg/L worst single sample: 1070 µg/L	2/17	SYR4	2012–2017
Di(2-ethylhexyl) Phthalate	2.2 µg/L 37% of the EPA limit 6 µg/L	1/2	SYR4	2017
Xylenes, Total	1.02 µg/L 0% of the EPA limit 10000 µg/L	1/24	SYR4	2013–2019

85 contaminants tested, none detected

1,1,1-Trichloroethane1,1,2-Trichloroethane1,1-Dichloroethylene1,2,4-Trichlorobenzene1,2-Dichloroethane1,2-Dichloropropane11Cl-PF3OUdS2,4,5-TP2,4-D4:2 Fts6:2 Fts8:2 Fts9Cl-PF3ONSAdonaAntimony, TotalArsenicAtrazineBhc-GammaBenzeneBeryllium, TotalChlorobenzeneCadmiumCarbofuranCarbon TetrachlorideChlordaneChromiumDichloromethaneDalaponDinosebDiquatEndothallEndrinEthylbenzeneGlyphosateHexachlorobenzeneHfpo-DaHeptachlorHeptachlor EpoxideHexachlorocyclopentadieneLassoMercuryMethoxychlorMonochloroacetic AcidNetfosaaNfdhaNmefosaaNitriteOxamylPfbaPFBSPfdaPfdoaPfeesaPfhpaPfhpsPfhxaPFHXSPfmbaPfmpaPFNAPFOAPFOSPfpeaPfpesPftaPftrdaPfunaPentachlorophenolPicloramSeleniumSimazineStyreneTetrachloroethyleneThallium, TotalTolueneTotal Polychlorinated Biphenyls (PCB)ToxapheneTrichloroacetic AcidTrichloroethyleneVinyl Chloridecis-1,2-DichloroethyleneLithiumO-DichlorobenzeneP-Dichlorobenzenetrans-1,2-Dichloroethylene

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Frequently asked questions about Jefferson Waterworks

Is Jefferson Waterworks tap water safe to drink?

EPA monitoring detected 22 contaminants in Jefferson Waterworks'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 Jefferson Waterworks's water?

EPA monitoring detected Fluoride, Copper, Combined Radium (-226 And -228), Lead, Combined Uranium, and others. The full list with the level and data source for each is above.

How many people does Jefferson Waterworks serve?

Jefferson Waterworks reports serving 7,926 people in Wisconsin, per its EPA record.

Has Jefferson Waterworks had any water quality violations?

The EPA has 59 violations on file for Jefferson Waterworks, of which 52 are health-based (a contaminant limit or required treatment was breached) and 1 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.