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Onalaska Waterworkswater quality report, rewritten

Serves
18,000
Connections
5,110
Water source
Groundwater
Based in
Onalaska, WI
County
La Crosse
Owner
Local government

ZIP codes served: 54650

PWSID WI63203272026 edition · EPA data

Read this first

  • Copper The 90th-percentile result was 1.5 ppm, above the 1.3 ppm action level.

No health-based violations on file since 2016.

What handles it

What was found

Highlighted: above the health goal. Circled: above the legal limit in at least one sample. Every scale puts the legal line at its middle.

Copper

Comes from pipes, often your own

1.5ppm

90th percentile, 2013

The 90th-percentile result was 1.5 ppm, above the 1.3 ppm action level.

What handles it

EPA SDWIS, lead and copper monitoring periods ending 2013. The pointer marks the latest period; each blue tick is an earlier one.

PFBS

Comes from the source

4.2ppt

Highest of 8 samples; found in two

Below EPA’s hazard index benchmark of 2,000 ppt. PFBS has no legal limit or health goal of its own.

What handles it

EPA UCMR 5, samples taken from Jan. 10, 2023 to July 11, 2023. Each blue tick is one sample where it was found.

Tested and not found

Below EPA’s minimum reporting level in every sample taken from Jan. 10, 2023 to July 11, 2023. Not found means not measured above that level, which is not the same as zero.

  • 11Cl-PF3OUdS
  • 4:2 FTS
  • 6:2 FTS
  • 8:2 FTS
  • 9Cl-PF3ONS
  • ADONA
  • HFPO-DA (GenX)
  • Lead
  • Lithium
  • NEtFOSAA
  • NFDHA
  • NMeFOSAA
  • PFBA
  • PFDA
  • PFDoA
  • PFEESA
  • PFHpA
  • PFHpS
  • PFHxA
  • PFHxS
  • PFMBA
  • PFMPA
  • PFNA
  • PFOA
  • PFOS
  • PFPeA
  • PFPeS
  • PFTA
  • PFTrDA
  • PFUnA

Violations since 2016

No health-based violations on file with EPA since 2016.

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?

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.

Compare five-year costs

Filters with those claims on a certifier’s listing

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

What this report cannot tell you

  • Levels of everything else. Federal bulk data carries results for PFAS, lithium, lead and copper, and violations for the rest. Nitrate, arsenic, disinfection byproducts and other levels are in Onalaska Waterworks’s own annual report, which it must send you every year.
  • 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.
  • Anything after the latest data. SDWIS data is from 2026 Q2; UCMR 5 samples are from Jan. 10, 2023 to July 11, 2023.

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