Willmar water quality

Updated 2026-10-22 · Minnesota · Affiliate disclosure

We read 13 results from Willmar’s 2025 water quality report. No results over a legal limit; 2 above a health goal or guideline.

Serves about 21,045 people · Water system ID MN1340016 · Read the district’s 2025 report (opens in a new tab)

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Results from the 2025 report

Each number is copied from the district’s report and links to the page it’s printed on. Where the report lists several plants, wells or purchased water, the highest is shown.

ContaminantResultHealth goalLegal limitWhat it means
Gross alpha (radioactivity)highest measured · sampled 2024 · Wells / treated water · 2025 report, page 46.4 pCi/L0 pCi/L15 pCi/LAbove the health goalThe health goal is zero
Radium (combined 226 + 228)highest measured · sampled 2024 · Wells / treated water · 2025 report, page 42.2 pCi/L0 pCi/L5 pCi/LAbove the health goalThe health goal is zero
Bariumhighest measured · sampled 2024 · Wells / treated water · 2025 report, page 40.33 ppm2 ppm2 ppmBelow the health goal
Chlorinehighest running annual average · range 0.66 to 1.01 · Distribution system · 2025 report, page 50.95 ppmNone set4 ppmBelow the legal limit
Disinfection byproducts (HAA5)highest running annual average · range ND to 4.6 · Distribution system · 2025 report, page 54.6 ppbNone set60 ppbBelow the legal limit
Disinfection byproducts (TTHM)highest running annual average · range 0.8 to 1 · Distribution system · 2025 report, page 51 ppbNone set80 ppbBelow the legal limit
Fluoridehighest running annual average · range 0.51 to 0.78 · Wells / treated water · 2025 report, page 50.64 ppm1 ppm4 ppmBelow the health goal
Mercuryhighest measured · sampled 2024 · Wells / treated water · 2025 report, page 40.07 ppb1.2 ppb2 ppbBelow the health goal
Nitrate (as N)highest measured · range 0.15 to 0.62 · Wells / treated water · 2025 report, page 40.62 ppm10 ppm10 ppmBelow the health goal
Sulfatehighest measured · range 0.65 to 76.7 · sampled 2023 · Wells / treated water · 2025 report, page 776.7 ppm—250 ppm guidelineWithin the guideline
Lithiumhighest measured · range ND to 35.7 · sampled 2024 · Wells / treated water · 2025 report, page 734 ppbNone setNoneNo health limit
PFBA (a PFAS)as reported · range ND to 2 · Wells / treated water · 2025 report, page 71.45 pptNone setNoneNo health limit
Sodiumhighest measured · range 28.8 to 42.4 · sampled 2023 · Wells / treated water · 2025 report, page 742.4 ppmNone setNoneNo health limit

Utility results describe the whole system, measured where water enters the pipes, not your tap. Your home’s plumbing can add lead or copper. 4 numbers we weren’t sure about are held back until a person checks.

EPA testing for PFAS and lithium

EPA’s own nationwide testing (UCMR 5) found these in Willmar’s water between May 2024 and Nov 2024. These are EPA lab results, separate from the district’s report. Anything not listed was not detected.

  • Lithium35.7 ppbFound in 3 of 4 samples · highest resultAbove EPA’s health reference level of 10 ppb (a guide, not a legal limit)

Source: EPA UCMR 5 occurrence data. The highest single result is shown; one high sample doesn’t mean every glass is that high.

What you can do

Nothing here is an emergency notice: if the district has a violation, it must tell customers directly. If you’d like to lower these at your tap, these are the treatments that remove them, and the catalog shows the models certified for each. Ranking is by certified removal; commissions never change the order.

Radium and uranium

Found: Gross alpha (radioactivity), Radium (combined 226 + 228)

What removes it: Reverse osmosis.

See filters that remove it

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