Minneapolis has some of the best-treated tap water of any major American city. It’s won national taste tests. The city’s water department runs a state-of-the-art treatment facility that processes Mississippi River water through a rigorous multi-step process.
But “well-treated” and “problem-free” aren’t the same thing. Minneapolis — and the broader Twin Cities metro — faces three converging water quality challenges that residents should understand.
PFAS: The 3M Legacy
Minnesota’s PFAS problem is one of the most well-documented in the country, and it traces directly to 3M Company’s manufacturing operations in the east metro area.
For decades, 3M’s Cottage Grove and Oakdale facilities manufactured PFAS-containing products, including Scotchgard fabric protector and AFFF firefighting foam. Waste disposal practices contaminated groundwater across Washington County and eastern Dakota County. The contamination plume affects drinking water wells serving hundreds of thousands of people in Woodbury, Cottage Grove, Lake Elmo, Oakdale, and surrounding communities.
In 2018, the State of Minnesota reached an $850 million settlement with 3M — at the time, one of the largest environmental settlements in state history. The funds have been used to build water treatment systems, connect communities to clean water sources, and conduct ongoing monitoring.
Minneapolis’s surface water supply from the Mississippi is less directly affected than east metro groundwater wells, but PFAS compounds are ubiquitous in the environment. UCMR 5 testing has detected PFAS in treated water across Minnesota at varying levels.
The Minneapolis Water Treatment and Distribution Services division monitors for PFAS and other emerging contaminants. Current levels in Minneapolis tap water have generally been below EPA’s newly established MCLs, but the regulatory landscape continues to tighten.
Lead Service Lines: Inventory and Replacement
Minneapolis has an estimated 17,000 to 22,000 lead service lines remaining in its distribution system — a legacy of construction practices from the 1880s through the 1930s.
The city launched a lead service line replacement program and has been working to inventory every service connection. Under EPA’s LCRI, all lead service lines must be replaced within 10 years. For Minneapolis, the estimated cost runs into the hundreds of millions.
The city offers a cost-sharing program for homeowners, but the private-side portion of the service line (from the curb stop to the home) has historically been the homeowner’s financial responsibility — a significant equity issue, since older housing with lead lines is disproportionately located in lower-income neighborhoods.
Minneapolis uses orthophosphate corrosion control to minimize lead leaching from pipes, and the city’s lead testing results have generally remained below the EPA action level of 15 parts per billion. But public health researchers increasingly argue that there is no safe level of lead exposure, especially for children.
Mississippi River Source Water
Drawing from the Mississippi River means Minneapolis’s raw water quality is influenced by everything upstream — agricultural runoff, municipal wastewater discharges, industrial releases, and stormwater from the Twin Cities metro itself.
Key concerns include:
- Nitrates and phosphorus from agricultural operations in the upper Mississippi watershed. While treatment removes these to safe levels, source water quality has been trending worse in some tributaries.
- Pharmaceuticals and personal care products — Treated wastewater discharged upstream introduces trace levels of medications, hormones, and other compounds. Current treatment processes weren’t designed to remove these, though activated carbon and advanced oxidation can help.
- Chloramine disinfection — Minneapolis uses chloramines (chlorine combined with ammonia) rather than free chlorine for residual disinfection. Chloramines are effective at controlling disinfection byproducts but can cause issues for kidney dialysis patients, aquarium owners, and some individuals with chemical sensitivities.
- Seasonal algal blooms — Nutrient loading in the Mississippi can produce cyanobacterial (blue-green algae) blooms that create taste and odor issues and, in extreme cases, toxin concerns.
Minnesota’s Regulatory Environment
Minnesota has been more proactive than many states on water quality regulation. The Minnesota Department of Health (MDH) has established health-based guidance values for over 40 PFAS compounds — well ahead of EPA’s federal standards. The Minnesota Pollution Control Agency (MPCA) has pursued aggressive enforcement against polluters.
The state’s 2018 settlement with 3M created a conceptual framework that other states have tried to replicate: holding manufacturers accountable for contamination cleanup rather than passing costs entirely to ratepayers and taxpayers.
What Minneapolis Residents Can Do
- Check your service line status. The City of Minneapolis maintains a lead service line map and inventory. Contact the Water department to confirm what connects your home.
- Use cold water for cooking and drinking. Hot water dissolves lead more readily from pipes and solder.
- Request a free lead test kit. Minneapolis and MDH periodically offer free lead testing for residents.
- Consider filtration. A pitcher filter certified to NSF/ANSI 53 reduces lead. For PFAS, reverse osmosis (NSF/ANSI 58) or activated carbon filters (NSF/ANSI P473) are effective.
- Check MDH’s well water resources if you’re on a private well in the metro area, especially in the east metro PFAS-affected zone.
The Bottom Line
Minneapolis’s water system is well-run and the city has invested heavily in treatment. But the 3M PFAS legacy, aging lead infrastructure, and Mississippi River source water challenges mean residents shouldn’t assume everything is perfect just because the water tastes good.
The Twin Cities’ water story is actually a case study in what happens when a major corporation contaminates a region’s groundwater — and what it costs to clean up. The $850 million 3M settlement sounds enormous until you realize it’s a fraction of the total long-term cost.
If you’re concerned about your water quality, a certified water treatment professional can test your water and advise on the right filtration or treatment system for your specific situation.