PFAS | Stillwater, MN

About Stillwater's Drinking Water

The City of Stillwater’s water utility serves about 20,600 people with approximately 6,800 total connections. On average, the City delivers 2.05 million gallons of water per day (MGD) to its customers. On peak water use days, the City has delivered up to 4.99 MGD.

The City’s drinking water comes from a groundwater source called the Prairie Du Chien-Jordan and Jordan aquifers through eight wells ranging from 200 to 305 feet deep. The City does not utilize the Saint Croix River as a source of water for the community. The water is treated with chlorine and fluoride in accordance with Minnesota Department of Health (MDH) standards. The hardness of the City’s water is 13.2 grains, or 225 parts per million (ppm).

Water is distributed to Stillwater customers through a network of pipes and pump stations over three different pressure zones. Water storage is provided by one water tower and three ground storage tanks. Water services, which connect the property to the city water system, are owned by and are the responsibility of the property owner.

The City produces an annual Consumer Confidence Report which provides customers with information about drinking water quality. The full report is available at this link: CCR 2025 Water Report .

What is PFAS?

Per- and polyfluoroalkyl substances (PFAS) are a family of manmade chemicals that have been widely used in consumer products since the 1940’s. PFAS can be found in water, soil, air, and food as well as materials found in our homes or workplaces including

Water-repellent clothing, non-stick cookware, paints, sealants, wood stain, and some personal care products.
Food packaging, including grease resistant paper, microwave popcorn bags, pizza boxes and candy wrappers
Food, including fish caught from water contaminated by PFAS and dairy products from livestock exposed to PFAS.
Fire fighting foam in aqueous film-forming foams (AFFFs) used to extinguish flammable liquid-based fires.
Biosolids – for example fertilizer from wastewater treatment plants that is used on agricultural lands can affect ground and surface water and animals that graze on the land.

Taken from the Environmental Protection Agency: PFAS Explained | US EPA

What level of PFAS in Drinking Water is Safe?

The Minnesota Department of Health (MDH) uses health-based values to evaluate health risks from individual PFAS substances. Health guidance values are designed to protect the most vulnerable populations for up to a lifetime of exposure. If more than one PFAS is found in drinking water, MDH evaluates their additive health risk using the Health Risk Index.

There is little to no health risk from drinking water with PFAS levels at or below guidance values. Drinking water with a PFAS Health Risk Index under one presents little to no health risk.

Drinking water with PFAS levels above guidance values or the Health Risk Index poses a potential health concern. It does not represent an immediate health risk. The guidance values are based on multiple safety factors and are overprotective for most people.

PFAS are emerging contaminants – meaning that there is a new awareness or understanding about how they affect public health. PFAS, like other emerging contaminants, are the focus of active research and study, which means that new information is released frequently, and the understanding of risks is evolving.

Community water systems with elevated PFAS can take actions to reduce PFAS levels. These systems can lower PFAS levels through treatment or reduced pumping from contaminated wells. For more information, please check out the MDH website: PFAS Testing of Public Water Systems - MN Dept. of Health (state.mn.us)

Which well is serving my home?

What are the potential health effects of consuming water with PFAS?

According to MDH, consuming water with PFAS above the health-based guidance values, which are designed to protect the most vulnerable populations for a lifetime exposure, can increase risk of health effects. These increased health effects include:

Immune suppression such as decreased vaccination response
Lower birth weights
Increased risk of kidney and testicular cancer
Changes to liver function such as higher cholesterol and elevated liver enzymes
Thyroid disease and dysfunction

What local, state, and federal agencies are invloved in making sure our drinking water is safe?

City of Stillwater: Provides water services to residents and businesses within the community.
Minnesota Health Department (MDH): Responsible for ensuring safe drinking water and enforcement of the Safe Drinking Water Act (SDWA). MDH performs regular testing of community water systems. MDH has developed health-based guidance values to represent levels for several PFAS in drinking water.
Minnesota Pollution Control Agency (MPCA): Responsible for preventing, managing and the cleanup of PFAS pollution. Grants in aid for PFAS mitigation in community water systems is overseen by MPCA.
Environmental Protection Agency (EPA): Responsible for the Safe Drinking Water Act (SDWA). The EPA sets national health-based standards to protect against naturally occurring and man-made contaminants that may be found in drinking water. The SDWA defines a contaminant as anything other a molecule of water.

What is a Maximum Contaminant Level in Drinking Water?

What is a Health Based Guidance Value?

An HBV is the level of a contaminant that can be present in water and pose little or no health risk to a person drinking that water. HBVs are guidance used to make decisions about managing the health risks of contaminants in groundwater and drinking water. HBVs are updated when significant new information is available. HBVs do not consider the cost and technology of prevention and/or treatment and may be set at levels that are costly, challenging, or impossible for a water system to meet.

Where can I find the Minnesota Health Department’s PFAS testing results for drinking water?

Does the City have information about the level of PFAS in the water coming out of the tap in my home or business?

My property is served by a privately owned well. How do I know if my water has PFAS?

I am interested in installing a Home Water Treatment System. Does MDH have information for me to consider?

Who do I call if I would like to talk to a City staff member about the City’s water?