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Please note: This page contains information about perflukoroalkyl substances (PFAS), which were previously referred to as perfluorochemicals (PFCs). Learn more about this change.

PFAS Update: March 2, 2018$850 million settlement provides funding for cleaning up drinking water
In 2010, Minnesota’s attorney general sued 3M Company alleging that the company’s production of chemicals known as PFAS had damaged drinking water and natural resources in the southeast Twin Cities metro area, including Woodbury. On Feb. 20, 2018, the State of Minnesota and 3M reached a settlement agreement, with the state receiving a grant from 3M for $850 million.

The court-approved agreement specifically outlines providing a clean, sustainable supply of drinking water as a top priority. It also indicates that improvements will be primarily focused on the cities of Woodbury, Afton, Cottage Grove, Lake Elmo, Newport, Oakdale, St. Paul Park and the townships of Grey Cloud Island and West Lakeland. Projects could include treating drinking water from existing wells, providing alternative sources of drinking water for cities or private well owners, or connecting homes served by private wells to municipal drinking water systems.

While the city's water is safe to drink today, there have been significant operational changes made due to the presence of PFAS in the aquifer. The city looks forward to working with the state agencies and other impacted communities to develop water treatment solutions that will provide safe drinking water for generations to come.

Details about the settlement and how the funds could be used are available on the Minnesota Pollution Control Agency website.

Community members who have questions about Woodbury water operations may contact Public Works at or (651) 714-3720.

View the press release from the PCA

PFAS Update: Feb. 7, 2018
The Minnesota Department of Health released new findings today related to the health impacts of PFAS found in some east metro communities’ water systems, including Woodbury’s. 

Water from Woodbury’s municipal water system remains safe to drink. The city will continue to operate the water system in the same manner as it does today.

View the press release from MDH

Please note: The information on this page is based on 2016 and 2017 testing and values. The MDH determines the sampling frequency and sites for PFAS. The sites and frequency can vary from year to year based on results. 

The Minnesota Department of Health (MDH) has been monitoring City of Woodbury municipal wells for perflukoroalkyl substances (PFAS) since the early 2000s. A specific type of PFAS – called PFBA – was originally reported in Woodbury wells in 2007. In addition, monitoring results in 2012 (due to advancements in detection technology) began identifying the presence of other PFAS including PFPeA, PFHxA, PFOA, PFBS, PFHxS and PFOS. However, the concentrations detected were below the Health Risk Limits (HRLs) established by MDH. (HRLs have not yet been established for PFPeA, PFHxA and PFHxS. MDH Uses the health based value for PFOS (0.027 ug/l) as a stand-in (or “surrogate”) for PFHxS.)

In 2016, the U.S. Environmental Protection Agency (EPA) reduced its drinking water protective guidance level for two specific PFAS, PFOA and PFOS, from 400 and 300 parts per trillion to 70 parts per trillion. EPA studies indicate exposure to PFOA and PFOS at high levels may result in an increased risk of adverse health effects. Read the complete advisory on the MDH website.

Water from Woodbury municipal wells met all state and federal drinking water standards in 2016 including the 2016 updated EPA protective guidance levels for PFOA and PFOS.

In late 2016, MDH announced it was reviewing studies and methods used by the EPA to determine whether its own health-based values need to be lowered and if so, what the values should be. MDH has completed their review and in May 2017 updated its protective guidance level for two specific PFAS historically found in Woodbury wells. The new health-based guidance values, based on daily consumption over a lifetime, for PFOA and PFOS are 35 and 27 parts per trillion (previously 300 parts per trillion). MDH scientists updated the values to better reflect new state-level analysis of the potential for mothers to pass along the chemicals to fetuses and nursing infants. In September 2018, MDH formally adapted the health based guidance value for PFOA of 35 billion parts per trillion as its enforcable health risk limit.

In November 2017, MDH notified the City of Woodbury that of Woodbury’s 19 municipal wells, water from five wells-based on the most current data-exceed either a PFAS health based guidance value (HBV) and/or a health risk index (HRI) value. Several of these exceedances are only slightly above the HBV or HRI and have been below those values on previous sampling events. MDH indicates that by the time Woodbury water is reaching faucets, the amount of PFOA and PFOS is under the new HBV. MDH recommendations are based on daily consumption over a lifetime.

Woodbury made operational changes that were implemented immediately upon the issuance of the new MDH HBV. These operational changes reduced use of the identified impacted wells. Woodbury operates a single water system. What this means is that water from all 19 wells in the system can and does mix resulting in a decrease in concentrations of detected parameters in the water system. Due to mixing in the system, reduced use of the identified impacted wells, and rotation in well operation, proximity to a production well does not pre-determine ones use of water from that well.

The city’s highest priority is the health and safety of its residents. Woodbury will continue working with MDH to monitor its water and assess if additional sampling, monitoring, or other actions are necessary.

Private Water Supply Wells
As a result of the EPA’s new guidance and MDH updated HBV for PFOA and PFOS, MDH is sampling private wells within Washington County and will issue additional drinking water advisories as needed. Until their private wells are tested, residents who have concerns about their health can take steps to reduce their potential exposure to PFAS. Information on point-of-use filters and other steps people can take in their homes can be found on the MDH website.

Residents who have questions about their private water supply well and whether it is impacted by this change should contact MDH.

Below is a chart outlining PFAS monitoring results for Woodbury municipal wells completed to date in 2018:

PFAS type

Amount (combined range in all 19 wells)

MDH Health Risk Limit (HRL)

MDH Health Based Guideline (HBV)

2016 EPA Guideline


<0.05 to 0.43 parts per billion (ppb)

7 parts per billion (ppb) or 7,000 parts per trillion (ppt)




<0.035 to 0.045 ppb

0.035 ppb or 35 ppt


70 ppt


<0.025 to 0.021 ppb

0.3 ppb or 300 ppt

0.027 ppb or 27 ppt

70 ppt


<0.05 ppb

7 ppb or 7,000 ppt

2 ppb or 2,000 ppt



<0.025 to 0.055 ppb

No HRL established

PFPeA and PFHxA = N.A.  

PFHxS = 0.027 ppb or 27 ppt*


* = MDH Uses the health based value for PFOS (0.027 ppb or 27 ppt) as a stand-in or “surrogate” for PFHxS

“Parts per billion” means the number of units of the chemical, in its pure form, found in every billion units of water. 

“Parts per trillion” means the number of units of the chemical, in its pure form, found in every trillion units of water.

For a general perspective, the City of Woodbury pumped approximately 2.6 billion gallons of water in 2017. That means a PFAS detected at a level of 0.025 ppb (parts per billion) would equal about an 8-ounce cup (or 0.06 gallons) of the substance in 2.6 billion (2,600,000,000) gallons of water.

About PFAS
PFAS were made by 3M in Cottage Grove and by other companies around the world for use in household and industrial products. PFAS wastes were disposed of in several landfills in Washington County including Lake Elmo, Oakdale and in southern Woodbury near Woodbury Drive (3M Woodbury site). The source of the PFAS in the Woodbury groundwater has been identified as these landfills.

Visit the MDH website for more information about PFAS in groundwater

Remediation Activities
In 2011, the Minnesota Pollution Control Agency (MPCA) completed remediation activities at these sites to reduce the amount of pollutants released from these sites in the future.

3M, under direction from the MPCA, continues active site remediation. For the Woodbury site, remaining contamination is captured by pumping approximately 1.25 billion gallons of water annually to a treatment plant and discharging it to the Mississippi River.

Visit the MPCA website for more information about the remediation activities.

Related MDH links
PFOS-PFOA advisory