Arsenic In Wisconsin Well Water

Arsenic in Wisconsin well water is an increasingly hot topic with new regulations in the state that match the EPA’s standard of 10 ppb (parts per billion).

There are a few areas with high geographic predisposition to failed readings.  It’s largely New England, Death Valley, and then that Wisconsin-shaped thing on the map that is unfortunately Wisconsin.

Arsenic in Water MapAbout Arsenic

Arsenic is a naturally occurring toxic metal that can be introduced or increased by any number of factors, some natural like erosion and others man-made through industrial processes.  Probably one of the worst parts of this toxic contaminant is that it is odorless and tasteless.

In general, arsenic is much more likely to be found in deep water sources like wells versus surface water like lakes and streams.

The health risks associated with arsenic are highly varied.  Chronic effects have been related to cancer of the bladder, lungs, skin, kidneys, liver, and prostate.

Arsenic Well Tests and Buying or Selling a Home

The real rub in Wisconsin is that private well owners now must have this tested as part of the well test related to the sale of a home.  The old limit was 50 ppb and largely impacted wells in Mequon and Cedarburg, plus higher concentrations in areas that did a lot of industrial work with paper or timber.

What this means for the average buyer, seller or even Realtor is that the game now is different than the game even just last year.  Just like a well bacteria test or nitrate tests, there is now an arsenic test and many homes that were “safe” last year are not today.

About Arsenic Water Treatment

Arsenic is different than most water softener ions in that it is negatively charged whereas all those hardness ions that we’re removing from dishwashers, washing machines and otherwise are positively charged.  So your water softener will not remove it.  It’s like using the wrong end of a magnet.

A further problem with arsenic is that there is not just one type.  For a shorter version and explanation, it’s basically either ready to be removed (“oxidized,” “pentavalent,” or As (V)) or the more pesky type (“reduced,” “trivalent,” or As (III)).

The EPA assists municipalities in identifying solutions to problems like these and issues things known as Best Available Technology (BAT).  These BAT statements are mostly directed at municipal water utilities.  For the sake of this discussion, we’ll skip activated alumina and modified lime softening.   Those aren’t economically feasible for the homeowner just like the best arsenic removal treatment, reverse osmosis, isn’t feasible for municipalities.

Does Reverse Osmosis Remove Arsenic?

Yes.  Well, kind of.  We are back to those two different types of arsenic.  Testing and industry claims are made on that oxidized or As(V) version of it.

So to make it pretty easy, a lower-end reverse osmosis system will stop some of the arsenic, but the same arguments against those exist anyway.  They start decaying virtually on install so you’re dealing with a lower amount of safety by the day and you’re either replacing that membrane regularly or just buying a new unit.

For the Kinetico K5 Drinking Water Station, the unique auxiliary ports allow us to supercharge the best system on the planet with additional, targeted filters to aid in a specific process.

On Milwaukee water, just like how we use our chloramine filter to get rid of that bleach/ammonia blend that they’re putting in the water, there’s an auxiliary cartridge for this problem. On well water, we have an arsenic filter that converts that As (III) into As (V).

At that point, the Kinetico membrane steps up and does what a Kinetico membrane does.  Our 3rd party validations tested out with a 99.3% average reduction.  The datasheet substantiating that claim is here:

As always, let us know if we can answer any questions specific to your scenario.

Water Doctors

Water Doctors


  1. Hello,
    Are there any contractors that install Kinetico Water Systems in the WestBend/Sheboygan, Wisconsin area?

    Thank you

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