Stearns County, MN Water Quality: PFAS & Lead

Stearns County, Minnesota: drinking water report. Stearns County in central Minnesota has a population of about 162,000, centered on St. Cloud.

Water Quality in Stearns County, MN

Stearns County in central Minnesota has a population of about 162,000, centered on St. Cloud. The city draws water from the Mississippi River and from deep wells. The county's location in the transition zone between the prairie and the northern forest means water sources are influenced by both agricultural activity to the west and natural organic matter from the north. Camp Ripley, a Minnesota National Guard training center, operates in adjacent Morrison County.

What the Data Shows

St. Cloud's Mississippi River intake receives water from a watershed that includes the agricultural lands of central Minnesota. According to the Minnesota Pollution Control Agency's 2024 monitoring data, nitrate and phosphorus levels in the Mississippi at St. Cloud have increased over the past decade, reflecting agricultural intensification upstream. The city's treatment plant uses granular activated carbon for taste, odor, and contaminant removal.

The EPA's UCMR5 data shows PFAS detections at low levels in the St. Cloud system. The St. Cloud Regional Airport has used AFFF firefighting foam. A 2024 Minnesota DOH assessment found PFAS in monitoring wells near the airport at concentrations near Minnesota's health-based value of 15 ppt for PFOS.

What Residents Should Do

St. Cloud's treatment plant provides effective multi-barrier treatment, but the river's agricultural loading means source water quality fluctuates with upstream conditions and seasons.

Check your water for current data on your area. For agricultural contaminants and PFAS, a reverse osmosis system at the kitchen tap covers the widest range. Our water filter guide covers options for river-sourced water systems. Pull your detailed report for seasonal data, and visit our Minnesota page for statewide patterns.

Beyond water: other exposures in Stearns County, MN

Drinking water is one exposure route. These federal datasets also cover Stearns County, MN.

Radon risk

The EPA places Stearns County, MN in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.

Lead paint risk

45% of homes in Stearns County, MN were built before 1980, and 16% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.

Air quality

Modelled annual fine-particle pollution (PM2.5) in Stearns County, MN averages 6.4 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.

How radon zones work · Air quality by county · Lead exposure guide

Stearns County, MN Water Quality by the Numbers

29 public water systems serving Stearns County, MN have EPA lead testing on record. The reported lead sample skews toward systems that already flagged a problem, so its exceedance rate is not directly comparable with other areas. 4 water systems serving Stearns County, MN carry a health-based EPA Safe Drinking Water Act violation.

Most-cited violation typeSystems affected
Revised Total Coliform Rule1
Arsenic1
Nitrate1
Ground Water Rule1

Source: EPA Lead and Copper Rule 90th-percentile tap sampling and EPA SDWIS Safe Drinking Water Act enforcement records, aggregated from the public water systems serving this county. Figures are counts of water systems, not a test of any individual home or tap.