Addressing PFAS in Groundwater
In the mid-2000s, per- and polyfluoroalkyl substances (PFAS) were found to have contaminated drinking water supplies in parts of the eastern Twin Cities, including in Woodbury’s groundwater supply. Research has been conducted to identify the source and level of contamination. Most of the contamination has been traced to four former disposal sites in Woodbury and surrounding communities as a result of biproducts from a 3M manufacturing facility.
In 2010, Minnesota’s attorney general sued 3M for accountability and funding to address the PFAS issues. On Feb. 20, 2018, the State of Minnesota settled a lawsuit against 3M in return for a settlement of $850 million. The City of Woodbury continues to advocate for allocation of this funding along with seeking other funding sources.
With most of the city’s 20 wells contaminated with PFAS levels exceeding the health risk standards, the City of Woodbury has been working with state agencies to fund both short-term and long-term drinking water system improvements.
Immediate Treatment of PFAS
The city designed, built, and is operating a temporary Water Treatment Facility to address current PFAS regulatory standards and to help bridge the water production gap until the new, permanent water treatment plant is designed and constructed over the next three to four years. In addition, three interim well treatment buildings are being constructed to treat water on-site at three production wells. Learn more about the temporary and permanent solutions on the Water Treatment page.
The water delivered to customers continues to meet all state water quality standards and guidelines for PFAS.
|3M Settlement & Advocacy
|City staff continues to advocate on behalf of the city to maximize treatment and funding from the 3M settlement.
|Nine Wells Removed from Service
|Nine wells exceeding MDH health index levels for PFAS were removed from service
|Drinking Water Master Plan
|Development of specific PFAS mitigation strategies for water supply and determination of long-term groundwater supply and treatment strategies through 2050.
|Declaration of Emergency
|The declaration of a local state of emergency freed up resources and provided the city opportunities to fast-track design/construction processes.
|Jan. 8, 2020
|Temporary Water Treatment Plant
|Design and construction of a GAC technology treatment plant to treat four wells. Learn more.
|Purchase of Land
|Purchased a parcel of land south of Hargis Parkway and east of Radio Drive for the future construction of the Woodbury Water Treatment Plant.
|Expansion of Temporary Plant
|Expansion of the temporary water treatment plant to treat two additional wells.
|Preliminary Engineering Report
|Analysis and development of details for the future water system including conceptual water treatment plant layout and treatment selection, pipeline analysis and alignment, non-treatment infrastructure needs, critical path items, and matrix of all project.
|Relocation of Existing House on Woodbury Water Treatment Plant Site
|Two new wells
|Addition of two new wells to meet current and future water demand. Both wells have been drilled - one well is currently operational and the second well will be operational in 2024.
|Design of the Woodbury Water Treatment Plant
|The design of the Woodbury Water Treatment Plant began in February 2023 and is scheduled for completion Fall 2024. The engineering associated with this project includes the design of the approved pipeline segments, water treatment plant layout, technology, and process designs, construction sequencing and scheduling, and many other factors that affect the ultimate construction of the plant and pipelines.
|Interim well treatment
|To accommodate the projected water demand and limited treated capacity until the full treated system is constructed, a strategy to treat PFAS directly at three wells was developed. Construction will begin in summer 2023 and will be completed and operational in February 2024.
PFAS, like other emerging contaminants, are the focus of active research and study, which means that new information is released frequently. The more that is learned about the chemicals the more specific and clear regulations will be developed. Currently, the Minnesota Department of Health (MDH) has set health-based values, health risk levels, and utilizes a health index calculation to provide a protection level for specific PFAS and groups of PFAS where specific levels have yet to be established.
- What is PFAS and how did it get in the water?
PFAS stands for per- and polyfluoroalkyl substances. The 3M Company made PFAS at its Cottage Grove facility beginning in the 1940s. They were commonly used in household and industrial products such as stain repellents, lubricants, fire retardants and suppressants, and more. PFAS wastes were disposed of at various locations in Washington County. The source of PFAS in Woodbury's groundwater has been identified as these disposal sites.
- I have a private well. How do I know if I am impacted by PFAS?
Private wells are the responsibility of private landowners. Private landowners should consider having their well tested.
- How many Woodbury municipal wells exceed PFAS water quality standards and guidelines?
As of July 2023, nine of the city's 20 wells currently exceed PFAS water quality standards and guidelines (an additional city well with a health advisory was permanently removed from service).
The temporary water treatment facility, located near the intersection of Valley Creek Road and Tower Drive, is currently treating water from six of these wells to meet water quality standards and guidelines for PFAS. The remaining three wells with health advisories have an interim treatment system at each well to meet water quality standards and guidelines for PFAS.
- Which well is serving my home?
The City of Woodbury has a one-pressure-zone system. This means no one particular well serves a specific area. The water is distributed throughout the system and well usage is rotated frequently as part of regular operation.
- What type of private, at-home treatment options are available?
There is information on the MDH regarding the effectiveness of home treatment options.
- I didn't know PFAS was in the water. Where can I learn more?
The city has been sharing updates about PFAS in the water since 2007 in the City Update newsletter, on the city's website, via its InTouch email notification system*, on its YouTube channel, and through the local media. Information also is provided in the annual Water Quality Report. Updates will continue to be provided through these channels. There also have been several public meetings on this topic since the beginning of 2019.
- Review the PFAS Treatment "Progress to Date" Timeline (scroll down the page to view)
- What is the long-term solution on treatment for PFAS and when will it be implemented?
The Minnesota Pollution Control Agency and Department of Natural Resources are leading the effort with the impacted communities under the 3M and Statement of Minnesota Settlement Agreement in identifying and approving the long-term treatment solutions. A pilot study of effective PFAS treatment technologies was implemented during the construction of the Temporary Water Treatment Facility and is still underway.
In February 2023, the city hired a team of engineers to begin design of the Woodbury Water Treatment Plant along with associated pipelines and infrastructure. The design will include recommendations from the pilot study to develop an effective long-term treatment process for the new water treatment facility. Many other factors for construction of the new Woodbury Water Treatment Plant including layout, process designs, construction sequencing and scheduling, and pipeline engineering and design are also being finalized during this phase.
The final design of the facility is estimated to be complete in 2024 and construction of the new facility will follow.
- Who will pay for the long-term solution for treatment of PFAS?
Approximately 90% of the water treatment plant and pipeline costs are anticipated to be paid for through the approximately $700 million (after legal fees) from the 2018 3M and State of Minnesota Settlement Agreement. Preliminary estimates indicate Woodbury’s water treatment plant will cost approximately $400 million, depending on several factors, including future possible changes to health standards and guidelines for PFAS.
With more than 83,000 residents, Woodbury is the largest city impacted by PFAS in the East Metro and the settlement funding is critical to providing a community-wide solution for generations to come.
The city’s share of the cost is expected to range between $25 million and $40 million based on 60% design estimates. These non-settlement funds are needed to treat wells that currently do not have health advisories and for other associated project items needed to position the community for the future. Woodbury is proactively planning to address these costs through responsible utility rate changes beginning in 2024. The city also sought and received $3.4 million in federal dollars in 2023 to help offset some of these future costs. In addition, the city continues advocating to the state co-trustees for the settlement to cover as much of Woodbury’s project costs as possible.
- How is the city’s growth impacting water quality and availability?
The city recognizes the need to carefully balance managing our water supply with continuing to meet the housing needs of the community. The City Council approved some significant changes to the city’s growth management policies July 19, 2023, that will delay the start of development in some areas of the city until we are closer to the permanent water treatment plant being operational later this decade. This action was taken as an additional contingency planning effort to mitigate the impacts of per- and polyfluoroalkyl substances (PFAS) on the water system. Previous contingent planning efforts approved by the City Council include adding temporary water treatment; changing lawn watering restrictions; managing wells to limit use of contaminated wells; modeling an additional water tower for storage; educating and communicating, and implementing other water efficiency measures.
This is the second time in the last two years the City Council has tightened the growth management policy to reduce the pace of growth in the community and added development controls and review opportunities. The City Council retains discretion on the timing of opening of sub-phases for development and timing of master planning efforts in advance of development activity.
- Is growth the most significant driver of water demand?
Modeling data shows the most significant driver of water demand within the community is the discretionary use of water for lawn irrigation by existing homes, businesses, and homeowners associations. The best thing residents, homeowners associations and businesses can do to help is to reduce lawn irrigation use during the summer months and follow the updated irrigation policy zones.