What is arsenic in well water?
Unlike PFAS or lead, arsenic in Minnesota is usually natural — it leaches into groundwater from the rock and sediment the water passes through. It's colorless, tasteless, and odorless, so there's no way to know it's there without a test.
Minnesota has more arsenic in its groundwater than most of the country. The Minnesota Department of Health estimates that about 1 in 10 private wells exceeds the federal drinking-water standard of 10 parts per billion, with higher rates in parts of the west and central metro.
Why arsenic in well water matters
Long-term exposure to elevated arsenic is linked to serious health effects, which is why the standard is strict. The catch is the invisibility: a city system tests and treats for arsenic as a matter of course, but a private well only gets tested if the owner does it — and many never have.
If you're on city water, your annual water report already accounts for arsenic. If you're on a well, this is one of the specific reasons the Minnesota Department of Health recommends testing — and one of the best reasons to take us up on the free in-home visit.
What to do about arsenic in well water
Arsenic is very treatable once you know it's there:
- Reverse osmosis at the kitchen sink removes arsenic from drinking and cooking water and is the most common home fix.
- Adsorptive media or anion-exchange systems can treat the whole house where levels warrant it.
The right choice depends on the arsenic level and its chemical form, which is why we start with a real number. Our free in-home test is the first step, and for well owners we'll walk you through the full Minnesota Department of Health testing checklist for the things a strip can't measure.