Water in Minnesota.
Minnesota's southeast karst region and farm belt have widespread nitrate exposure. The Twin Cities' East Metro is the original PFAS contamination zone — 3M's manufacturing operations there generated decades of groundwater contamination.
Minnesota's 3M PFAS settlement remains one of the largest environmental settlements in U.S. history.
How Minnesota regulates drinking water.
Strict state-level PFAS framework. Minnesota Department of Health Health-Based Values for PFAS predate federal action by years. State enforces PFAS at 5+ contaminants below detection-limit guidance.
Minnesota Department of Health — Drinking Water Protection
Minnesota's water history, in order.
The contamination events, regulatory shifts, and major settlements that define how this state thinks about drinking water today.
- 2010
Minnesota Attorney General sues 3M for $5B over East Metro PFAS contamination.
- 2018
3M agrees to $850M settlement for Minnesota PFAS damages — among the largest environmental settlements in U.S. history.
- 2023
Minnesota bans PFAS in most consumer products (Amara's Law) — most aggressive U.S. state ban.
The actual water you drink.
The physical rivers, aquifers, lakes, and reservoirs that feed Minnesota's public water systems. Source quality is the foundation of tap quality — and where the long-term protection fights happen.
- riverMississippi River
Twin Cities supply.
- aquiferPrairie du Chien-Jordan Aquifer
Twin Cities metro groundwater.
- lakeLake Superior
Duluth area.
- aquiferKarst aquifers (southeast)
Winona, Olmsted, Fillmore counties.
Source-water mix
~75% groundwater, ~25% surface water
Major cities served
Minneapolis · St. Paul · Rochester · Duluth · Bloomington
Who actually serves the water.
The largest public water systems in Minnesota by population served. Click your ZIP after to see the full live EWG report for your specific utility.
- Minneapolis Water DepartmentMinneapolis500Kserved
- Saint Paul Regional Water ServicesSaint Paul425Kserved
- Rochester Public UtilitiesRochester120Kserved
Where the contamination comes from.
Every state has a different industrial fingerprint. The industries below are the dominant historical and active contamination sources in Minnesota's drinking water systems.
3M's East Metro operations (Cottage Grove, Lake Elmo, Oakdale, Woodbury) — the original major U.S. PFAS contamination site. Mining (Iron Range) and forestry legacy in northern MN. Agricultural runoff drives nitrate in karst-region southeast.
What state data flags most consistently.
Drawn from EPA SDWIS sampling records, EWG state summaries, and regional regulatory action over the past five years. Read the full deep dive on each.
Nitrate
Fertilizer and animal waste runoff. Acutely dangerous for infants under 6 months.
PFAS (Forever Chemicals)
A class of ~15,000 synthetic chemicals that don't break down. Now regulated for the first time.
Trihalomethanes (TTHMs)
Byproducts of chlorinating water. Linked to bladder cancer at chronic exposure.
Risk isn't evenly distributed.
East Metro residents (Cottage Grove, Lake Elmo, Oakdale, Woodbury) face the most-documented PFAS exposure in the U.S. Southeast karst farmers face nitrate.
~20% on private wells. Southeast karst region (Winona, Olmsted, Fillmore counties) has the highest nitrate exposure.
What's coming for Minnesota's water.
Earlier ice-out on northern lakes affects source-water temperature regimes. Increasing intense rainfall events drive nitrate spikes in karst-region groundwater. PFAS movement through aquifers continues mapping.
Statewide mandate
MN Statute 121A.335 (2017) requires lead testing in all public school buildings. Minneapolis and St. Paul have completed multiple testing cycles with public results.
Five questions for your next Consumer Confidence Report.
Your utility is required to send you a Consumer Confidence Report annually. Most are dense and procedural. These are the questions worth following up on for Minnesota specifically.
- 1
Is my East Metro home in the documented 3M PFAS contamination zone?
- 2
If I'm in karst country, when was my well last tested for nitrate?
- 3
Has my school district posted recent lead testing results?
Most state regulators allow public records requests for the underlying lab reports behind your CCR — your utility should be able to provide them on request.
What's changed in Minnesota water law.
Drinking water regulation moves at the state level as much as the federal level. Below are notable recent bills and regulatory actions specific to Minnesota.
- 2023
Amara's Law (HF 2310) — bans intentionally added PFAS in 11 product categories by 2025, all by 2032.
- 2017
MN Statute 121A.335 — School Lead Testing mandate.
For East Metro PFAS: NSF/ANSI P473 or reverse osmosis. State of Minnesota provides POU filters in confirmed contamination zones.
We don't recommend brands — the NSF/ANSI certification number matters more than the name on the box.
This is the state. Your address is the answer.
State-level patterns don't tell you about your specific tap. Run your ZIP for the live EWG contaminant report on your utility — or build a personalized Water File for your household.
Source-water mix, utility counts, lead-service-line estimates, and private-well shares are approximate, drawn from EPA SDWIS public data and state primacy-agency summaries. Contaminant rankings reflect EWG state-level monitoring data and regional regulatory action — they are not exhaustive. Timeline events are publicly documented. See methodology for the full sourcing. Search EPA SDWIS for Minnesota