PFAS FAQs for the Garden and Homestead

The chemicals known as per- and polyfluoroalkyl substances (PFAS) have been widely used since the 1950s in products ranging from food packaging to fire fighting foam. PFAS have recently been recognized as contaminants in agriculture and are believed to largely be entering soil through the application of biosolids, industrial sludges and ashes, which may contain these compounds that are difficult to break down.

Over the past few years PFAS have emerged as a growing contaminant of concern for the food supply in Maine and elsewhere. Gardeners and homesteaders, as a critical piece of a healthy food system, have questions about how PFAS contamination is impacting food production. Here are answers to some common questions. 

We want to be responsive to your concerns.  If you have a PFAS question or concern related to gardening or homesteading specifically, please email Anna Libby at [email protected], and we will do our best to find answers and publish them in our monthly email newsletter for gardeners. We’ll update this page regularly as the situation evolves.

The chemicals known as per- and poly-fluoroalkyl substances (PFAS) have been widely used since the 1950s in products ranging from food packaging to fire fighting foam and are used to make products resistant to water, heat and stains. PFOA and PFOS are two of the better studied PFAS compounds, and are known to cause human harm in relatively small quantities. PFAS have recently been recognized as contaminants in agriculture and are believed to largely have entered soil and water through the application of biosolids, industrial sludges, and ashes, which may have contained these persistent compounds. 

It could be possible depending on the compost that is purchased. This resource from the Sierra Club offers an overview of how PFAS may enter the garden through compost. The document, toward the end, also indicates some tested products — including one purchased in Maine — that have elevated levels of PFAS. While biosolids are not permitted in organic production or in composts approved for use in organic production, there are other ways that PFAS can potentially contaminate compost. Unfortunately, the widespread low-level PFAS contamination of our environment means that a sensitive testing protocol is likely to find some amount of PFAS in all composts. There is no available guidance yet as to what may be considered a “safe” test result. We are encouraging customers to ask manufacturers if testing has occurred to gain a clearer picture of risk.

We often recommend getting a soil test from the University of Maine to look at soil fertility, or to check for heavy metal contamination, but those tests will not indicate if there are PFAS in your garden and their lab is not equipped to detect PFAS in any other tests.  

Currently, the state of Maine is testing for PFAS at many locations throughout the state, and is prioritizing sites that may have the highest risk of contamination. The state plans to eventually test all sites that received an application of biosolids, but this testing will take several years to complete. If you live near a Maine Department of Environmental Protection (DEP) licensed sludge or septage application site, you can request that the DEP test your well for PFAS here.

You can also use the DEP guidance available here to collect a well water sample yourself if you are concerned about contamination from a site nearby. The DEP does have reimbursement available, though only under certain circumstances which are outlined in that same document. 

A high water-test result may indicate that you would want to have garden soil tested.  If that is the case, you will want to use a contractor and use a lab that has been accredited to test for PFAS  (the state has compiled a list here).  If you are on municipal water, and know that your land has not had biosolids spread on it, cause for concern regarding PFAS contamination of soil may be minimal. If, however, compost or manure were bought in over the years, there may still be a risk of contamination. 

Please bear in mind that lab testing capacity is strained right now as the level of PFAS contamination continues to emerge, and homeowners may want to evaluate their level of risk based on currently available data prior to performing a test.

Even with results from a soil test, the sheer diversity of vegetable and berry species, combined with the fact that research into plant uptake of PFAS is still in its infancy, means that soil tests may not provide information that is immediately actionable. Research that will provide more guidance in the future is underway. 

Similar to compost, contamination could be possible depending on where the hay is produced and how the land has been managed, both historically and currently. Though biosolids are not permitted in organic production a legacy of prior PFAS contamination may exist on fields used currently for organic hay production.

We encourage customers to ask the seller if the product has been tested and to encourage the farm to work with the Department of Agriculture, Conservation and Forestry (DACF) or DEP to determine if their site is at high risk of having been contaminated. Testing is underway at farms across the state and many farms are waiting for testing or waiting for results due to the current high demand for testing, so answers may not be immediately available. The state is identifying and testing highest risk areas first.

Learn more and take action

Learn more
We have an overview of PFAS and our agricultural system in Maine which you can read here.

The DEP has an overview of their work on this issue here

Help out

MOFGA, alongside other partners in Maine, is working on several policy initiatives to make progress on this issue. Learn more about our state-level legislative priorities and how you can take action to support bills seeking to address PFAS contamination here and visit this page to send a letter to acting Food and Drug Administration (FDA) Commissioner Janet Woodcock asking the agency to act swiftly to better understand the scope of contamination across the country, establish safety standards, and immediately restrict the production and disposal of these forever chemicals. Thank you for taking action!

MOFGA staff are working across departments to offer up-to-date, reliable and responsive answers and resources to address members of our community impacted by PFAS contamination. This includes pushing for legislative action, offering one-on-one support for farmers, collaborating with partners to conduct research and advance our understanding of the issue, and providing direct financial support to affected farms. Click the button below to donate to MOFGA’s work on PFAS in Maine. Thank you for your support!

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