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Downsville Sanitary District

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
250 people
Connections
93
Water source
Groundwater
Based in
Downsville, WI
County
Dunn
Owner
Local government
Hardness
Hard
The ZIP code it serves

54751

The short answer

2 results are above the health goal. The worst: Arsenic, above the health goal. No health-based violations on file since 2016.

What handles it

What was found

Lead and copper: EPA SDWIS monitoring periods ending 2002 to 2023.

Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, chromium (total) and nitrate: Wisconsin’s own results, samples taken from June 16, 2020 to March 4, 2026, with EPA’s 2012 to 2019 file for earlier years.

Above the health goal2

Arsenic

Comes from the source

Above the health goal

2.3ppb

Highest yearly average, 2020 to 2026

Averaged by year, the highest was 2.3 ppb, in 2026: below EPA’s legal limit of 10 ppb, but above its health goal of zero. That was also the latest year on file.

What handles it

  • NSF/ANSI 58 look for “Arsenic (Pentavalent)<=50 ppb Reduction”
  • NSF/ANSI 53 look for “Arsenic (Pentavalent)<=50 ppb Reduction”

Lead

Comes from pipes, often your own

Above the health goal

1.0ppb

90th percentile, 2023

In the latest period, 9 in 10 homes sampled were at or below 1.0 ppb, below EPA’s action level of 15 ppb. The action level drops to 10 ppb on Nov. 1, 2027. EPA’s health goal for lead is zero.

What handles it

Below EPA’s limits3

Total trihalomethanes (TTHM)

Forms or is added in treatment

Below EPA’s limits

10ppb

Highest yearly average, 2022

Averaged by year, the highest was 10 ppb, in 2022, below EPA’s legal limit of 80 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.5 ppb, in 2016.

What handles it

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

Haloacetic acids (HAA5)

Forms or is added in treatment

Below EPA’s limits

5.6ppb

Highest yearly average, 2022

Averaged by year, the highest was 5.6 ppb, in 2022, below EPA’s legal limit of 60 ppb. That is the only year on file. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 5.1 ppb, in 2019.

What handles it

No certification claim covers this compound yet.

Fluoride

Forms or is added in treatment

Below EPA’s limits

0.24ppm

Highest yearly average, 2020 to 2026

2026, one sample: 0.24 ppm

Averaged by year, the highest was 0.24 ppm, in 2020, below EPA’s legal limit of 4.0 ppm. In 2026, the latest year on file, its one sample was 0.24 ppm. Earlier, from 2012 to 2019, EPA’s file shows a highest yearly average of 0.24 ppm, in 2017.

What handles it

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

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.”

  • NSF/ANSI 53

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: Arsenic (III) (50 ppb influent level)

  • NSF/ANSI 58

    Claims: Arsenic (Pentavalent)<=50 ppb Reduction, Lead Reduction

    For: Arsenic, Lead

    Other certifiers’ wording: Arsenic (Pentavalent)<=300 ppb Reduction; Arsenic (V) (300 ppb influent level)

At the tap, or for the whole house?

Lead and copper usually come from pipes and fixtures inside or near your home. A whole-house system sits where water enters, so it cannot catch what your own plumbing adds after it. For those, the filter that counts is the one at the tap. How whole-house systems compare.

Filters with those claims on a certifier’s listing

Disclosure: TapBuff earns a commission if you buy through some links on this page. It does not change which standard or filter we name. As an Amazon Associate, TapBuff earns from qualifying purchases. How TapBuff makes money

Compare five-year costs

The best reverse osmosis systems, ranked

The best water filters for lead, ranked

Hardness

Hard, typically 150 mg/L (8.8 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 8.8 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 is 1 monitoring or reporting violation: a sample missed, late or not reported.

What this report can’t tell you

  • Everything else. Arsenic, total trihalomethanes (TTHM), haloacetic acids (HAA5), fluoride, chromium (total) and nitrate results here are Wisconsin’s own from 2020 on, with EPA’s national file for 2012 to 2019. Downsville Sanitary District’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 June 16, 2020 to March 4, 2026.

Testing your own tap

Downsville Sanitary District’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 Downsville Sanitary District serves, in a straight line. Call first: certification is test by test, and not every lab takes samples from homeowners.

  • Dunn County Health Department

    Menomonie, WI · under a mile

    Certified for bacteria, nitrate

    (715) 232-2388

  • Menomonie Waste Water

    Menomonie, WI · under a mile

    Certified for bacteria

    (715) 232-2175

  • Commercial Testing Laboratory Inc.

    Colfax, WI · about 16 miles

    Certified for bacteria, nitrate, lead and copper, metals, minerals and other inorganics

    (715) 962-3121

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 WI6170263. Rebuilt from EPA data on Oct. 18, 2026.

Towns it serves

Also in Dunn County

All Wisconsin utilities

What to do next