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Union Center Waterworks

What EPA’s and Wisconsin’s records show in this utility’s water: nitrate, arsenic and other regulated chemicals; lead and copper; and violations since 2016, with the certification that handles each result.

Serves
225 people
Connections
130
Water source
Groundwater
Based in
Union Center, WI
County
Juneau
Owner
Local government
Hardness
Moderately hard
The 2 ZIP codes it serves

53962, 53968

The short answer

Nothing in EPA’s and Wisconsin’s records for this utility is above a health goal. That covers nitrate, arsenic and other regulated chemicals, plus lead and copper, not everything. No health-based violations on file since 2016.

What was found

Nitrate, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5), arsenic and chromium (total): Wisconsin’s own results, samples taken from Sept. 30, 2020 to Sept. 10, 2025, with EPA’s 2012 to 2019 file for earlier years.

Below EPA’s limits4

Nitrate

Comes from the source

Below EPA’s limits

2.9ppm

Highest sample; found in 5 of 5

2025, one sample: 2.2 ppm

The highest sample, in 2020, was 2.9 ppm, below EPA’s legal limit of 10 ppm. In 2025, the latest year on file, its one sample was 2.2 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 3.2 ppm, in 2019.

What handles it

  • NSF/ANSI 58 look for “Nitrate/Nitrite Reduction”
  • NSF/ANSI 53 look for “Nitrate/Nitrite (30 ppm challenge)”

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

7.2ppb

Highest yearly average, 2023 to 2025

2025, one sample: 2.8 ppb

Averaged by year, the highest was 7.2 ppb, in 2023, below EPA’s legal limit of 80 ppb. In 2025, the latest year on file, its one sample was 2.8 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 7.5 ppb, in 2019.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.084ppm

Highest yearly average, 2020 to 2023

Averaged by year, the highest was 0.084 ppm, in 2023, below EPA’s legal limit of 4.0 ppm. That was also the latest year on file.

What handles it

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

0.38ppb

Highest yearly average, 2023 to 2025

2025, one sample: 0.25 ppb

Averaged by year, the highest was 0.38 ppb, in 2023, below EPA’s legal limit of 60 ppb. In 2025, the latest year on file, its one sample was 0.25 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.67 ppb, in 2016.

What handles it

No certification claim covers this compound yet.

3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Lead

Hardness

Moderately hard, 83 mg/L (4.9 grains per gallon), at its one sampling point, 2017 to 2026.

Hardness is calcium and magnesium. EPA sets no limit for it: it shows up as scale on fixtures and in water heaters, and as soap that won’t lather. USGS calls water above 60 mg/L moderately hard, above 120 hard and above 180 very hard.

Softeners compared at 4.9 grains per gallon, salt includedSoftener or salt-free conditioner?Wisconsin water hardness, utility by utility

Violations since 2016

No health-based violations on file with EPA since 2016. There are 2 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Nitrate, total trihalomethanes (TTHM), fluoride, haloacetic acids (HAA5), arsenic and chromium (total) results here are Wisconsin’s own from 2020 on, with EPA’s national file for 2012 to 2019. Union Center Waterworks’s own annual report, which it must send you every year, has the contaminants this page does not show.

  • Your own plumbing. Lead results are the 90th percentile across homes the utility samples. Your home’s service line, solder and fixtures decide yours. A certified lab test is the only way to know.

  • What it means for your health. This page reports what the records show and EPA’s limits and goals; it is not medical advice. If you are worried about a health effect, talk to a doctor or your local health department.

  • Anything after the latest data. SDWIS data is from 2026 Q3; UCMR 5 didn’t sample this utility; Wisconsin’s results run from Sept. 30, 2020 to Sept. 10, 2025.

Testing your own tap

Union Center Waterworks’s results are for the water it sends out. What your own service line, solder and fixtures add shows up only in a test of your tap, by a lab Wisconsin certifies.

The 3 labs Wisconsin certifies closest to the area Union Center Waterworks serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Pure Water Labs, LLC

    Reedsburg, WI · about 14 miles

    Certified for bacteria

    (608) 225-3621

  • Pure Water Labs, LLC

    Lodi, WI · about 14 miles

    Certified for bacteria

    (608) 225-3621

  • CT Laboratories

    Baraboo, WI · about 27 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics, organic chemicals, disinfection byproducts

    (608) 356-2760

Wisconsin State Laboratory of Hygiene: Well water test kits ordered by phone and shipped free; you pay to mail the sample back, and the lab bills you after testing. Tests run from bacteria alone to a homeowner package covering bacteria, nitrate, fluoride, metals, hardness, volatile organic compounds and atrazine. Bacteria is $35, nitrate $35, lead $38, and the homeowner package $450, as of July 1, 2026. Public Environmental and Water Testing Prices, Wisconsin State Laboratory of Hygiene.

All 156 certified labs for Wisconsin

Sources

PWSID WI7290136. Rebuilt from EPA data on Oct. 18, 2026.

Also in Juneau County

All Wisconsin utilities

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