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Mazomanie 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
1,744 people
Connections
645
Water source
Groundwater
Based in
Mazomanie, WI
County
Dane
Owner
Local government
Hardness
Very hard
The ZIP code it serves

53560

The short answer

1 result is above the health goal. The worst: Uranium, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Haloacetic acids (HAA5), nitrate, fluoride, total trihalomethanes (TTHM), arsenic and chromium (total): Wisconsin’s own results, samples taken from Jan. 21, 2020 to Sept. 21, 2026, with EPA’s 2012 to 2019 file for earlier years.

Uranium: EPA’s compliance monitoring file, samples taken from July 12, 2017 to July 12, 2017. Newer results are in the utility’s annual water quality report.

Above the health goal1

Uranium

Comes from the source

Above the health goal

0.74ppb

Highest yearly average, 2017

Averaged by year, the highest was 0.74 ppb, in 2017: below EPA’s legal limit of 30 ppb, but above its health goal of zero. That is the only year on file.

What handles it

Below EPA’s limits4

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

31ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 31 ppb, in 2026, below EPA’s legal limit of 60 ppb. That was also the latest year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 12 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Nitrate

Comes from the source

Below EPA’s limits

2.2ppm

Highest sample; found in 11 of 14

2026 average: 0.86 ppm

The highest sample, in 2022, was 2.2 ppm, below EPA’s legal limit of 10 ppm. In 2026, the latest year on file, its two samples averaged 0.86 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest sample of 2.3 ppm, in 2014.

What handles it

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

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.86ppm

Highest yearly average, 2020 to 2026

2026 average: 0.68 ppm

Averaged by year, the highest was 0.86 ppm, in 2021, below EPA’s legal limit of 4.0 ppm. Its highest single sample was 1.4 ppm. In 2026, the latest year on file, its 20 samples averaged 0.68 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.58 ppm, in 2012.

What handles it

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

11.4ppb

Highest yearly average, 2020 to 2026

2026, one sample: 5.8 ppb

Averaged by year, the highest was 11.4 ppb, in 2024, below EPA’s legal limit of 80 ppb. In 2026, the latest year on file, its one sample was 5.8 ppb. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 10 ppb, in 2015.

What handles it

  • NSF/ANSI 53 look for “Trihalomethanes (TTHM) Reduction”
  • NSF/ANSI 58 look for “Trihalomethanes (TTHM) Reduction”
3 compounds tested and not foundBelow the reporting level in every sample. Not found is not the same as zero.
  • Arsenic
  • Chromium (total)
  • Lead

What handles it

A certification covers specific claims, not a whole standard. Look for these claims on the certifier’s listing, not the box. Wording varies a little: NSF writes “Lead Reduction,” WQA just “Lead.”

At the tap, or for the whole house?

These come with the water itself, so a whole-house system certified for the same claims treats every tap and shower. A filter at the tap treats drinking water for much less. How whole-house systems compare.

Filters with those claims on a certifier’s listing

None of the filters TapBuff has checked so far carry these claims. Search the certifier listings for the claim above.

Compare five-year costs

Hardness

Very hard, typically 309 mg/L (18.1 grains per gallon), across 2 sampling points, 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 18.1 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 4 monitoring or reporting violations: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Haloacetic acids (HAA5), nitrate, fluoride, total trihalomethanes (TTHM), arsenic and chromium (total) results here are Wisconsin’s own from 2020 on, with EPA’s national file for 2012 to 2019. Uranium comes from EPA’s file alone, which ends in 2019. Mazomanie Waterworks’s own annual report, which it must send you every year, has newer results for those and 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 Jan. 21, 2020 to Sept. 21, 2026; EPA’s compliance samples are from July 12, 2017 to July 12, 2017.

Testing your own tap

Mazomanie 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 Mazomanie Waterworks serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Water Quality Investigations

    Mt Horeb, WI · about 16 miles

    Certified for bacteria

    (888) 499-2507

  • Wisconsin State Laboratory of Hygiene

    Madison, WI · about 19 miles

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

    (608) 224-6260

  • Public Health Madison & Dane County

    Madison, WI · about 20 miles

    Certified for bacteria

    (608) 243-0357

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 WI1130239. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Dane County

All Wisconsin utilities

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