Guide to Investigating PFAS Risk on Your Farm

March 2025 Version. Content updated by Caragh Fitzgerald, Associate Extension Professor, Polly Shyka, Villageside Farm, and Ellen Mallory, Extension Professor. For questions, please contact Caragh Fitzgerald (cfitzgerald@maine.edu) or Ellen Mallory (ellen.mallory@maine.edu).

This guide was originally created by the Maine PFAS Cohort, made up of representatives from Northern Tilth, LLC, Maine Dept. of Agriculture, Conservation and Forestry, Maine Cooperative Extension, Winslow Agricultural, LLC, Maine Organic Farmers and Gardeners Association, Maine Farmland Trust, The Mitchell Center, and Sheepscot Valley Farm with support from the USDA National Institute of Food and Agriculture, Farm and Ranch Stress Assistance Network (FRSAN) project 2019-70028-30464 and 2020-70028-32729. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S Government determination or policy.

Please Note: this guide is a living document that will be updated regularly. It reflects the best available information at the time of the last update. Please bookmark this page and check back on a regular basis for the latest version.

Sections of this Guide:

Document Updates: March 2025

  1. Status of Maine’s Response to PFAS Contamination at Agricultural Sites
  2. Steps to Determine PFAS Risk Specific to Your Farm
  3. Mitigation Options for PFAS on Farms
  4. Support Resources
  5. Background Information and Understanding PFAS Pathways

Appendix A: Links to Important Resources
Appendix B: Historical Spreading Data Available from Maine DEP
Appendix C: Acronyms used in this document

Document Updates: March 2025

  • Throughout document. Updated agency contact information.
  • Throughout document. Reduced the use of the term “biosolids” and replaced with “sludge” or “sludge/septage” to be consistent with Maine state agency documents.
  • Throughout document. Removed testing and screening level requirements for sludge/ biosolids applied to soils. Soil application of sludge/biosolids ended in 2022.
  • Section 1. Provided more detail about DEP’s sampling and updated their progress as of May 2024.
  • Section 1 and throughout document. Changed the name of the “EGAD Site Types Map” to “PFAS Investigation Map” and its web address as per DEP changes. This map has also been called the “Septage and Sludge Map” in the past. The PFAS Investigation Map now includes test results sampled by DEP. These results were previously shown in the separate DEP “PFAS Data Map”, which is no longer available.
  • Section 1. Added that MOFA and MFT offer test reimbursement with no obligation to disclose results.
  • Section 2A. Added definition and classification of residuals.
  • Section 2A. Added links to DEP resources to investigate spreading history.
  • Section 2B. Under “Cost” updated DEP criteria for reimbursement, added the DACF program, and noted that the MOFGA/MFT program no longer has a requirement to share test results.
  • Section 2B. Changed link for list of accredited laboratories from the pdf of “Accredited PFAS Laboratories” to the CDC Maine Laboratory Accreditation webpage with directions to find the “Laboratories Accredited in Maine to Test PFAS in Drinking Water” list. This ensures that readers access the most up to date list of accredited PFAS laboratories.
  • Section 2C. Added section “Action and Screening Levels Explained”
  • Sections 2C, 3, and 5. Updated and consolidated these sections to improve flow, reduce repetition, and incorporate updated information about action and screening levels.
  • Section 3. Updated mitigation options with new information and resources.
  • Section 4A. Added information about the new PFAS Navigator Program.
  • Section 4B. Added information about the new Fund to Address PFAS Contamination.
  • Section 4B. Updated project types supported by the PFAS Emergency Relief Fund.
  • Section 5. Added new EPA enforceable PFAS levels in drinking water.
  • Section 5. Added Maine study of background PFAS concentrations.
  • Appendices A, C, D, E, F. Updated and consolidated into a single Appendix A to link directly to resources.
  • Appendix B. Added that record-keeping was not required for Class A spreading events.

1. Status of Maine’s Response to PFAS Contamination at Agricultural Sites

The state of Maine has allocated significant funding for dealing with issues related to PFAS and is dedicated to supporting the landowners who are affected by land application of wastewater sludge and septage, fire fighting foam, Department of Defense sites, landfills or other PFAS sources. In 2021, Maine’s Department of Environmental Protection (noted hereafter as “DEP”) began sampling soil and groundwater at all sites that were licensed for land application of Class B biosolids (wastewater sludge and septage) at no cost to the landowner. This equates to over 1,000 sites around the state. (See Section 2A for definitions of sludge, septage, and biosolids).

The DEP has ranked the state’s licensed sludge application land into four tiers to prioritize their sampling, with Tier 1 locations being those where the risk is perceived to be greatest. The tier rankings are based on a number of factors including the volume of material applied, whether the material is likely to have contained PFAS, whether sites with a similar source have shown greater than anticipated impacts on soil and water, and proximity of the site to homes. Tier 1 and 2 sampling was completed in 2023. Tier 3 site sampling is underway and will continue into 2025. Once the initial testing at a site is completed, DEP determines whether an expanded, “step-out” investigation is warranted.

The licensing and management for septage land application sites are not the same as for sludge. Land receiving septage is not part of the tier ranking. Sampling of land receiving septage is anticipated to be completed in 2024.

The DEP and the Maine Department of Agriculture, Conservation and Forestry (DACF) work in close collaboration when a property is being utilized for commercial agricultural purposes. In these cases, typically DEP will conduct testing and interpretation of results for residential drinking water sources while DACF will conduct sampling and interpretation of results for soil or agricultural media. In addition to conducting testing services, DACF will provide individualized management recommendations to limit or eliminate the risks from PFAS contamination of farm products. DACF also has many financial resources available to help producers make both short and long term adjustments (see Section 4).

If farms conduct private testing for PFAS and find levels of contamination which exceed state standards, there is potential for the farm to be reimbursed for the analysis costs by the state (DEP or DACF) if certain criteria are met. Criteria that the state considers for testing reimbursement are detailed below in Section 2B. The farm would need to share those test results with DEP and DACF in order to trigger the assistance described above. Farmers who have questions about the process or timeline can contact Maine DEP (pfas.dep@maine.gov, 207.287.5842) or Meagan Hennessey, PFAS response coordinator at DACF (meagan.hennessey@maine.gov, 207.592.3795).

Note that the Maine Organic Farmers and Gardeners Association and Maine Farmland Trust offer a program for commercial farms and Indigenous producers of food and/or medicine to pay for PFAS testing with no requirement to share results. See Section 2B. for details.

For the most up-to-date information on the state’s PFAS testing and timeline, see the web page PFAS and Maine DEP. Further details of DACF’s assistance can be found at https://www.maine.gov/dacf/ag/pfas/index.shtml.

2. Steps to Determine PFAS Risk Specific to Your Farm

2A. Determine the land application history of your farm

The first step to deciding whether PFAS may be a risk on your farm is determining whether there is any history of “residuals” application on your farm since the 1980s. Residuals are defined by the Maine Department of Environmental Protection as “solid wastes generated from municipal, commercial or industrial facilities that may be suitable for agronomic utilization” (Maine DEP Rules, Chapter 400, section 1, Ss.). Residuals may have value as a source of crop nutrients or soil amendment and can refer to the following types of materials, as well as others:

  • Sewage sludge (also known as “biosolids”) – A solid or semisolid material that remains after liquids are separated from sewage and that is then physically and chemically treated to meet certain standards for land application.
  • Septage – Liquid and solid material removed from septic tanks and other sewage holding systems.
  • Bioash – A byproduct of burning biomass for energy production.

Determining the history of residuals application on your farm may be relatively easy if you have owned your farm since the 1980’s, but it is more difficult if the land has changed hands one or more times. Maine DEP has made several resources available to the public that can assist you in learning whether your land was ever licensed as a land application site for residuals, whether any residuals were actually applied, how much was applied, and in what years. These resources include:

An important caveat: Different classes of residuals and biosolids have different licensing requirements. Class A products have met certain quality criteria that are above the requirements for Class B products. Class A products can be used anywhere and do not require a site-specific license, whereas Class B products can only be applied on fields that fall under a site-specific license. Note that PFAS testing of biosolids (sludge) and agricultural soils was not required as part of the Class B land application licensing process until March 2019.

The map listed above only describes septage and class B biosolid applications. Class A biosolids products could have been legally spread on land that would not appear in the public records because there was not a site-specific license requirement for use of that particular product. Conversely, a site that was licensed to spread Class B biosolids or septage may show up in public records as a land application site but may not have actually had materials applied to the land. Appendix B provides details on how to research Class B land application history for your farm.

2B. Determine whether and how to conduct sampling

If you know that sludge or septage was applied to your land, you may want to sample soil, water, animal forage, and/or crops for human consumption. If you are unsure and concerned about your property’s potential residuals history, DACF is available to discuss specific scenarios and in many instances can conduct testing. In the event that DACF determines testing can not be justified at the current time, technical advice can still be offered.

It is possible to collect water samples yourself and submit them to a PFAS testing laboratory, provided you follow the strict guidelines to prevent contamination of the sample (see resources in Appendix A). Guidelines also exist for collecting soil samples yourself, but because the process to determine what and how to sample is more complex than with well water, it is recommended that these types of samples be collected by trained field technicians familiar with PFAS sampling requirements.

If you are doing your own testing, it is important to call the lab ahead of sampling to determine the requirements specific to that lab such as paperwork procedures, shipping requirements, and sampling protocols. Additionally, commercial labs are primarily set up to deal with business clients who send samples on a regular basis; some labs do not accept samples from one-time individual clients.

General considerations for determining what and how to sample specific to PFAS:

Cost: PFAS analysis costs between $250 and $500 per sample. For this reason, farmers may want to think carefully and prioritize their sampling efforts in tiers of importance. If the first round of sampling yields levels of PFAS contamination that are concerning, additional sampling may be needed.

There are a number of programs available in Maine to help pay for or reimburse individuals for initial analytical costs (up to a certain amount), provided certain criteria are met.

The DEP reimbursement program is for the cost of initial testing of drinking water and does not include labor. The reimbursement criteria are that:

  • Water sampling is conducted in general accordance with the DEP’s PFAS Water Sampling for Homeowners guidance and/or soil samples are collected by a qualified environmental professional,
  • A Maine-accredited and DEP-approved laboratory was used,
  • Test results are shared with DEP, and
  • The source of PFAS can be tied to a DEP-licensed sludge or septage land application site or other remediation-type site, as verified by the DEP.

The DACF reimbursement program is for the initial testing of soil, farm water, and other media, such as milk or feed. The reimbursable costs include third-party contractors who performed the sampling and laboratory fees. Reimbursement criteria are that:

  • Test results are from a DEP-approved laboratory,
  • Test results must be shared with DACF, and
  • There must be a verified history of sludge/septage application at the farm, or history that the farm utilized off-farm manure, feed, or other inputs contaminated with PFAS, or be located near a DEP-identified location that received sludge/septage.

For more information about these two programs see, DEP’s PFAS Water Sampling for Homeowners guidance document and the “Additional DACF Financial Assistance” section of DACF’s PFAS Assistance webpage.

Maine Organic Farmers and Gardeners Association (MOFGA) and Maine Farmland Trust (MFT) offer the PFAS Emergency Relief Fund to cover the upfront costs of testing with no requirement to share test results (i.e., complete confidentiality). Applications are reviewed weekly. All commercial farms (a farm that sells at least $2,000 to consumers outside of the household) and self-identified Indigenous producers are eligible. To be paid for by this program, the testing of purchased inputs needs to be approved by the producer of those inputs. Learn more about MOFGA and MFT’s PFAS Emergency Relief Fund.

Type of Samples: Soil, water, milk, animal products, forage, and increasingly produce, are the substances most often sampled on farms. Understanding the pathways of PFAS through the environment can help to prioritize which materials to sample based on the history and current operations on your farm. See Section 5 of this guide for more information.

PFAS investigations often begin with testing the farm’s product (i.e. milk, vegetables, beef, hay, or something else) and expanding to testing soil and irrigation water if concerning levels are found in the product. One limitation with this approach, however, is that the limit of laboratory detection of PFAS for solid samples is generally higher than for liquid samples. This means, for example, that hay can test non-detect and still result in noticeable levels of contamination of the products from animals consuming the hay, particularly for dairy products. An additional limitation is that action levels have only been set for two farm products at this time: milk and beef. For other products, it is difficult to determine what represents a harmful level of contamination if PFAS are detected. Additional action levels are expected in the future. In the meantime, farms will have to carefully consider what type of sampling will provide them with actionable information.

Cross Contamination: Remember, PFAS is found in a multitude of consumer products, such as hygiene products, clothing, and food packaging. It is easy for either you, your clothing, or your sampling equipment to contaminate a sample with PFAS, especially when you consider that PFAS compounds are detected at extremely low concentrations (in the parts per billion, ppb and parts per trillion, ppt).

Choosing a Lab: The State of Maine has approved certain labs to analyze a variety of sample media for PFAS compounds. See Maine CDC’s Maine Laboratory Accreditation website to find a PDF of the “Laboratories Accredited in Maine to Test for PFAS in Drinking Water” list. Note there are an increasing number of labs in Maine that are on this list. If you are doing the sampling on your own, you will need to contact the lab ahead of sampling to obtain:

  • PFAS-free sampling containers
  • Instructions on how to collect and return the sample to the lab
  • Pricing information
  • Estimated turn-around times for results

You will also need to specify which PFAS compounds you would like to include in the analysis; Maine DEP is currently testing for the “Maine suite of 28” PFAS compounds for many environmental media. For drinking water, it may make sense to ask for just the 6 compounds included in Maine’s drinking water standard (PFOS, PFOA, PFHpA, PFNA, PFHxS, and PFDA). Note certain agricultural sample types (“media”) must be tested using specific laboratory methodologies for accurate results.

2C. Evaluate the Lab Results

Maine DEP has published a helpful guide to interpreting PFAS lab results, How to Read and Interpret My PFAS Laboratory Data Report (PDF).

PFAS Units of Measurement:

Even at very low concentrations, PFAS compounds may be harmful to human health. See Section 5 of this guide and the U.S. CDC ATSDR PFAS website for information on the health risks of PFAS exposure. Measuring these very small units can be difficult for many laboratories, depending on the technology used in that lab. For example, one part per trillion is equivalent to a single drop of water in 20 Olympic-sized swimming pools.

PFAS concentration in solids, including soil, manure, beef, forages, and sludge/septage, is usually measured as parts per billion (ppb). In liquids, including water and milk, PFAS concentration is usually measured as parts per trillion (ppt). The following conversions may be useful:

1 ppb = 1 ng/g = 1 μg/kg = 1 μg/L

1 ppt = 1 ng/kg = 1 ng/L

1 ppb = 1000 ppt

Action and Screening Levels Explained

The first step in evaluating your results is to compare them to the current PFAS action and screening levels (PDF) published by the state of Maine. These levels are developed by the Maine CDC or the US EPA. Action levels are the concentration of the contaminant above which the material should not be consumed and indicate when some remedial action should be taken.

Screening levels are used in situations where the material tested is not the material that is consumed, such as the screening level for soil for producing corn silage that feeds dairy cows. The soil screening level accounts for the transfer of PFAS from soil to corn silage to cows to milk and is the level of PFAS in soil that may result in milk that exceeds the milk action level. When soil screening levels are exceeded, further analysis customized to the site will be needed to determine appropriate next steps.

As of this writing, the most current set of action and screening levels is from December, 2023 Maine PFAS Screening Levels (PDF). These screening and action levels are expected to be updated and added to as more is learned about PFAS toxicity and behavior in agricultural environments.

Water

Maine’s current Interim Drinking Water Standard is 20 ppt for the sum of 6 PFAS compounds: PFOS, PFOA, PFHpA, PFNA, PFHxS, PFDA. If your drinking water tests above this level, it is considered a potential health risk and you should take action to reduce the levels in your drinking water. As well, depending on the level of contamination and your agricultural products, it may be necessary to reduce the levels of contamination before using your water for livestock or irrigation. See Section 3: Mitigation Options.

Note that the United States Environmental Protection Agency set new standards for PFAS in drinking water on April 10, 2024. Maine is currently reviewing the EPA standards and plans to adopt ones at least as stringent.

Soil

Determining the level of concern for soils is more complicated than for water. One reason is that there are no federal guidelines. Another is that soil is not directly consumed, and so screening levels for crop- and product-specific pathways need to be developed. Maine CDC has published PFOS soil screening levels for several crop-specific transport pathways related to dairies and milk production. These screening levels are back-calculated from what are considered acceptable levels in milk. These are specific to dairy systems and are the only agriculture-specific soil screening levels published by the state so far. There are no screening levels available yet for other production systems or PFAS compounds.

Forage and Produce

Evaluating PFAS levels in forage and produce is also complicated due to site-specific factors and the lack of guidelines. Action or screening levels for forage and produce have not been published but research is underway to develop them. If irrigation water and/or soil levels are high, it can be expected that levels in the forage or produce will also be elevated. However, without screening levels, it is difficult to determine at what point “elevated” PFAS levels equate to a real health risk. Maine’s CDC, in collaboration with other state entities, is researching the factors affecting transfer of PFAS from soil to crops and is continuing to develop screening standards for farm-produced food products. They are a good source of information for questions about risk levels (see contact information in Appendix A).

Milk

Maine’s current action level for milk is 210 ppt (ng/l) for PFOS. The state will not allow milk to be shipped or sold that has exceeded the action level for PFOS. Any producer whose milk tests over this level should contact Meagan Hennessey, Director of PFAS Response, Maine Department of Agriculture, for guidance (see contact info in Appendix A). If your milk is condemned, the USDA Dairy Indemnity Payment Program (DIPP) can provide some funding for the discarded milk for a limited period of time. You would need to contact the USDA Farm Service Agency (FSA) (contact information in Appendix A) who would work in conjunction with DACF to facilitate payments for milk or depopulated animals.

Beef

Maine’s current action level for beef is 3.4 ppb (ng/g) for PFOS. This means the state considers meat with a PFOS concentration above this level as adulterated and will not allow it to be sold or delivered for sale. If farms test their beef and find levels exceeding this action level, the farm should take action to determine the source of PFAS, and reduce the intake of PFAS in the herd. They should also contact Meagan Hennessey, Director of PFAS Response, Maine Department of Agriculture, for guidance (contact information in Appendix A) to determine appropriate next steps.

3. Mitigation Options for PFAS on Farms

With the lack of clarity around what level of PFAS is cause for concern in agriculture products, especially in forage and produce, it can be difficult to know when and how to take action. This section attempts to provide some guidance, but this guidance is limited by the gaps in current knowledge related to PFAS toxicity and behavior in the environment and lack of federal guidelines. Although there are no legal requirements to self-report PFAS levels that exceed the published screening levels, if levels of concern are detected on your farm, it is prudent to reach out to the Department of Agriculture Conservation and Forestry (DACF), Department of Environmental Protection (DEP), and/or the Maine Center for Disease Control (CDC) to get the most up-to-date information and support available. A list of contacts for these agencies is provided in Appendix A.

In addition to accessing state resources, you might consider the following mitigation steps for water, soil, and forage/produce. The exact mitigation steps will vary from farm to farm, but the current range of options may include:

Water

If your well water is above Maine’s current Interim Drinking Water standard, which is 20 ppt for the sum of the following six PFAS: PFOA, PFOS, PFDA, PFNA, PFHxS, and PFHpA, you will want to switch to bottled drinking water right away and consider installing an activated carbon filtration system. Keep in mind that Maine is likely to adopt lower standards in the near future after reviewing the stricter rules for PFAS in drinking water that the U.S. EPA issued in April 2024. See Section 2C.

If your well supplies drinking water and is located near an application site for materials such as wastewater sludge or septage, or a remediation-type site as verified by the DEP, it is likely that either Maine DEP or Maine DACF will provide financial assistance for installing an activated carbon filtration system, and will also provide bottled drinking water until the filtration system is installed. These types of systems have proven effective in removing PFAS compounds from water. You should also work with the Maine DEP to determine if neighbors’ wells may also be contaminated. If contaminated well water is used for watering livestock or for irrigation, there is also a risk that the well water has contributed PFAS to milk, meat, eggs, soil and/or crops and you should discuss the results with DACF. See Appendix A for Maine DEP and DACF contact information.

Soil

At this point, there are no documented means of effectively reducing PFAS levels in soil. One option for fields with soil testing high in PFAS is to switch to crops that accumulate lower levels of PFAS (such as switching from hay to corn or small grains, or from leafy greens to tomatoes or peppers). Another is to stop using the field for crop production. Before making drastic changes, it is recommended to reach out to University of Maine Cooperative Extension and/or Maine DACF for guidance on changes in cropping that may lessen risks. DACF has educational resources on PFAS risk reduction for dairy and beef producers available on their PFAS Response website.

Forage and Produce

Elevated PFAS levels in forage and/or produce is likely the result of contaminated irrigation water, soil, or both. If initial sampling only involved forage or produce, and PFAS was detected, it would be prudent to follow up with testing of soil and irrigation water to determine the source of the contamination, and then take the mitigation steps appropriate for water and soil as needed.

For forage, another potential strategy is to dilute affected feed with “clean” feed, thereby lowering the overall PFAS concentration that livestock are consuming. Additionally, routine sampling over a period of months may provide greater peace of mind, as those results will better represent the entire forage supply. Even the most carefully collected sample only provides a snapshot of the forage in a bunk, or from a group of hay bales. “Hot spots” in individual bales or in bunkers can quickly elevate PFAS levels in milk.

Contaminated produce is a more serious problem, mainly because there is a direct route to human consumption (as opposed to the forage-animal-human pathway). At this time there are no guidelines for safe levels of PFAS in produce intended for human consumption. The Maine CDC is working to develop more guidelines for specific types of produce. Maine CDC or DACF are available to discuss specific scenarios.

Milk

Although PFAS compounds have been dubbed “forever chemicals” because of their persistence in soils and water, they do have a “half-life” in animals. This means that once the source of the PFAS in animals’ diets has been removed or reduced, the PFAS levels in the animal will gradually reduce over time. This process is termed “depuration.” In lactating animals, one of the major routes of excretion is through the milk. If the sources of contamination can be fully identified and effectively eliminated, the level of PFOS contamination will eventually reach acceptable levels. This may not be feasible in all instances (for example, if some moderately contaminated feed must be used for economic practicability) and the timeframe can be long. However, multiple dairy operations are successfully managing PFAS using this strategy. Since milk is the major route of excretion of PFOS from dairy cows, it is important to check fresh heifers as they enter the milking string, especially if they had been exposed to contaminated feed and water (both forage and milk when they were calves) and will need to be depurated before their milk is added to the bulk tank.

Beef

If soil and/or forage sampling has revealed PFAS contamination on your farm, the best strategy for beef is to segregate the forage harvested from the contaminated fields. Then, be sure that only “clean feed” is fed to beef cattle during the finishing stage. Researchers are developing models to predict PFAS in beef products based on feed sources, contamination levels, feeding strategies, and elimination pathways, and have made significant progress. Farms with specific questions should reach out to DACF.

4. Support Resources

4A. Finding PFAS Support Resources

Financial, technical, medical, and community support is available for farmers impacted by PFAS in Maine through Maine DACF, DEP, CDC, UMaine Extension, MOFGA, MFT, and others. Farmers concerned about PFAS are encouraged to reach out directly to these entities (see contact information in Appendix A) or to contact the PFAS Navigator Program.

The PFAS Navigator Program is a voluntary, confidential, and no-cost program that provides one-on-one assistance and support to PFAS impacted farmers including:

  • Helping producers identify their needs, interests, and goals related to PFAS contamination,
  • Helping them connect with PFAS-related technical, medical, and financial assistance programs and resources, and

Providing support for navigating forms and applications for PFAS-related assistance programs.
Farmers interested in receiving assistance can fill out a Participant Interest Form on the PFAS Navigator Program website or contact the program coordinator (See Appendix A).

4B. Financial Support

Department of Agriculture, Conservation and Forestry Resources

For farms where PFAS contamination of soil or groundwater is above screening levels, DACF will test products, additional farm field soils, water sources, and feed to determine and monitor levels of contamination. DACF will pay for these sampling efforts.
Farmers whose soil, water, or farm products have been confirmed to be above PFAS action and screening levels and who have partnered with DACF to investigate the scope of contamination at the farm are eligible to apply for the following types of PFAS Assistance for Maine Farmers as part of DACF’s PFAS Response and PFAS Fund programs:

  • Administrative Cost Grants
  • Income Replacement
  • Technical Assistance/Professional Services
  • Clean Feed Assistance
  • Equipment and Input Costs
  • Infrastructure
  • Debt Service on Existing Loans
  • New Loan Assistance

More information about these programs can be found at the PFAS Assistance for Maine Farmers link above.

For information regarding all of DACF’s resources and support programs, including land purchases, research, and health initiatives, visit DACF’s PFAS website). For specific questions, email pfas.dacf@maine.gov or see contacts in Appendix A.

Maine Organic Farmers and Gardeners Association (MOFGA) and Maine Farmland Trust (MFT)

MOFGA and MFT are jointly administering a PFAS Emergency Relief Fund to support any Maine farm dealing with potential per- and polyfluoroalkyl substances (PFAS) contamination. They currently offer:

  • Testing Grants – to pay for initial PFAS testing on farms that choose to do their own testing.
  • Farmer Wellness Fund – Support access to mental health services for impacted farmers.
  • Income Replacement Grants – to provide short-term income replacement for farms that the Department of Agriculture, Conservation and Forestry (DACF) has identified as having high test results.
  • Infrastructure Investment Program – to cover the upfront costs of infrastructure necessary to farmers’ responses to PFAS contamination while DACF develops longer-term support programs.
  • Tax Preparation Support – to provide financial support to farms to navigate the implications of their participation in PFAS related support programs

For details about what’s covered, eligibility, and how to apply, click on the program link above. For questions, contact MOFGA or MFT (see contacts in Appendix A).

U.S. Department of Agriculture, Farm Service Agency

The USDA Dairy Indemnity Payment Program (DIPP) can provide some funding for depopulated animals or discarded milk for a limited period of time in the case when milk is condemned for exceeding the PFAS action level. The USDA Farm Service Agency (FSA) would work in conjunction with DACF to facilitate payments. (See FSA contact information in Appendix A)

4C. Crisis Support

5. Background Information and Understanding PFAS Pathways

Background Information

Per- and poly-fluoroalkyl substances (PFAS) are synthetic compounds that have been used widely in manufacturing and consumer products since the 1950s. As a result, traces of these compounds are now nearly everywhere in the environment. The carbon-fluorine bond that typifies these compounds is the strongest chemical bond in organic chemistry, giving them unique properties including water and oil repellency, heat resistance, and stain resistance. It also makes them very difficult to degrade. Because they do not readily break down in the environment, PFAS levels accumulate over time in environmental media such as soil and water, and in animals, including humans.

According to the U.S. Environmental Protection Agency’s (EPA) CompTox chemicals database, there are more than 14,000 PFAS compounds in existence, and the number is growing as industry invents new forms within this chemical class. Two of the oldest and most commonly studied PFAS, PFOS and PFOA, were used in manufacturing and consumer products such as Scotchguard™ (by 3M),Teflon™ (by Dupont), furnishings, aqueous film-forming foams (AFFF) for suppressing fire, clothing, and paper products. They were phased out starting in the early 2000’s due to health concerns, but PFOA and PFOS may still be produced and used in products imported from overseas. Additionally, newer, less-studied compounds continue to be approved for use by the United States Environmental Protection Agency (US-EPA) and the list of consumer products containing PFAS continues to grow.

The U.S. CDC estimates that PFAS can be found in the blood of 97% of Americans, though recent reports indicated that the blood levels of PFOS and PFOA are declining due to the phase out of these two compounds in the U.S. According to the U.S. Agency for Toxic Substances and Disease Registry, some, but not all, studies have shown that PFOS and PFOA may increase cholesterol levels, decrease how well the body responds to vaccines, increase liver enzymes, increase risk of high blood pressure or pre-eclampsia, decrease infant birth weight, and high PFOA exposure may increase the risk for kidney and testicular cancer. More information on how exposure to PFAS can affect human health, see the U.S. CDC ATSDR PFAS website.

PFAS contamination in other states has been linked, in some cases, to direct discharge from industrial manufacturing facilities. However, in Maine the contamination is more likely to be from the site of an AFFF discharge (such as military bases or fire training facilities), closed landfills, or the land application of waste water treatment residuals (including land application of septage). When wastewater is treated, there are two products: clean water, which is recycled back to rivers and the ocean, and solids (wastewater sludge). These solids are landfilled, sent to an incinerator, or, before the practice was banned in 2022, further processed into “biosolids” for land application on farm fields. (Note: The terms “sludge” and “biosolids” are often used interchangeably.)

Land application of sludge/biosolids was considered a “beneficial reuse” for decades, because it returns nutrients and organic matter to the soil. Wastewater treatment facilities may receive residential wastewater, industrial wastewater, or some combination of the two. Industrial wastewater, if coming from a factory that used PFAS compounds in its operations, is likely a greater contributor of PFAS than residential wastewater. For this reason, residual materials may have very different levels of PFAS, depending on the wastewater treatment facility and the unique mix of wastewater coming into the facility at any given time.

Because of the phase-out of PFOS and PFOA beginning in 2001, more recent sludges are likely to have significantly lower levels of these compounds than material that was spread in the 1980s and 1990s. Materials produced at wastewater treatment facilities with industrial wastewater inputs are likely to have higher levels than facilities that receive primarily residential wastewater. Improvements in modern laboratory techniques means that we can now measure these compounds in soils and other media at the extremely low concentrations at which they may be affecting human health.

Since 2019, Maine DEP has taken many steps to evaluate the levels of PFAS in soil and groundwater resulting from the land application of sludge and septage. In many cases, this land application took place at agricultural sites. As Maine DEP continues to roll out its soil and groundwater investigation to a statewide program, data obtained to date has indicated that PFAS levels are not uniform at different sites where sludge or septage were applied. As the investigation continues, the DEP is hoping to learn more about where PFAS is at the highest levels and how it moves within the environment. While there have been some documented cases in Maine where sludge/septage use has contributed to exceptionally high levels of PFAS in soils and groundwater, there are also many examples where long-term use of sludge/septage has resulted in mildly elevated, but not extremely high, levels in soil and groundwater.

Maine is one of only a few states that has published screening levels for PFAS for soil and the only state to have action levels for agricultural products. A screening level is a concentration of a chemical in an environmental medium that serves as a threshold to determine if further action (beyond analysis) is needed. Maine was one of the first states to establish soil screening levels for some PFAS compounds as they apply to sites receiving sludge (2.5, 5.2 and 1,900 parts per billion for PFOA, PFOS and PFBS, respectively).

Until early 2024, Maine’s enforceable PFAS drinking water standards were more restrictive than the EPA’s guidelines. As of April, 2024, the EPA Maximum Contaminant Level (MCL) was set as 4.0 ppt for PFOA and PFOS and at 10 ppt for PFNA, PFHxS, and HFPO-DA (known as GenX chemicals). The EPA has also set MCL goals of 0 ppt for PFOA and PFOS. There is a multi-year phase-in plan to allow public water systems to reach these MCLs. Maine is reviewing these new standards. When review is complete, these or stricter standards will be adopted.

In Spring 2022, as part of Maine’s 130th Legislative Short Session, four PFAS related bills were passed: LD 1875, LD 1911, LD 2013 and LD 2019. Bill LD 1911, An Act To Prevent the Further Contamination of the Soils and Waters of the State with So-called Forever Chemicals, banned the practice of land-spreading wastewater sludge as a fertilizer, and banned the sale of sludge based compost in Maine. This bill also allows Maine DEP to require sampling of wastewater treatment plant effluent – the liquid waste or sewage discharged into a river or the sea – for PFAS.

There are still many unknowns related to how PFAS travels through the environment and what represents a “safe” level. Maine’s guidelines can be expected to continue to be updated as the science of PFAS evolves. This guide is based on the best information available at this time, but it is expected that “safe” levels will ultimately be lower than currently adopted.

Understanding Pathways of Exposure

We are all exposed to PFAS from a variety of sources in everyday life – stain-resistant carpeting, nonstick cookware, grease- and water-proof food packaging, fabric softeners, waterproof clothing, cosmetics, and many other products. When we wash dishes and clothing and attend to our own hygiene, all of that wastewater goes either to a septic system or a public wastewater treatment facility. Industrial factories such as paper mills that use PFAS and other facilities may also contribute their wastewater to public treatment facilities or generate sludge at their own wastewater treatment plants. The solids that are either pumped from a home septic system, or are left over from the wastewater treatment process, are referred to as sludge, and this sludge is often processed to reduce pathogens. After processing (which may take the form of composting or lime-stabilization), the sludge material is known as “biosolids.” In Maine and many other states and countries, biosolids were often applied to agricultural fields. This practice is now prohibited in Maine.

The concentration of PFAS in a field that was spread with sludge will vary depending on how many applications were made, the application rate, and the exact type/source of the sludge or residual material. Sludges produced at different wastewater treatment facilities have different levels of PFAS contamination, depending on the relative amounts of residential vs. industrial waste streams entering the facility. The time period in which the material was applied is also a factor; the two most commonly studied PFAS compounds, PFOA and PFOS, were much more widely used in the 1980s and 1990s, and were phased out beginning in 2001. Farm fields that were repeatedly spread prior to 2001 may have higher levels of PFOA and PFOS, compared to those that were spread with sludge after 2001.

Once PFAS have accumulated in soil, they may leach to the groundwater or stay in the soil, depending on the characteristics of the specific PFAS compound and the soil and geology. There are two pathways for PFAS in soil to make their way into plants: through direct uptake by roots, and through physical contamination of the edible portion of the plant (above-ground or below-ground) coming into contact with the soil and adhering to the harvested plant material.

Preliminary research indicates that different parts of plants accumulate PFAS at different rates. As a general rule, the vegetative parts of plants (ex., leafy greens, grass forages, etc) accumulate more PFAS than the fruiting or reproductive parts of plants (ex. tomatoes, corn ears, grains). Initial investigations by the Maine Center for Disease Control (CDC) and the University of Maine Cooperative Extension indicate that corn silage will take up less PFAS into the plant than forage grasses, and that transfer to grain corn is minimal. Ongoing research is needed to refine and verify these findings, but for now, these apparent differences in uptake rates by different types of crops provide producers with options on how to mitigate the risks of elevated PFAS levels in their soils, as discussed above in Section 3 of this guide.

If irrigation water and/or wash water is contaminated, then in addition to the pathways described above for soil-to-plant transport, there is the added pathway of contaminated water coming into direct contact with the above-ground portions of the plant.

A quick note on background levels:

If your land has no history of sludge or septage use and is not located adjacent to a parcel with a history of sludge/septage use, firefighting foam use (often associated with Department of Defense sites) and/or PFAS manufacturing plants, it is unlikely that your soil and well water are highly contaminated. However, it is still possible that testing for PFAS could reveal trace levels in soil, which are referred to as background levels. A study by the University of Vermont (PDF), which has been widely cited, indicates that presumed background levels in soils from Vermont towns and parks have a median concentration of 0.39 ppb for PFOA and 0.68 ppb for PFOS. Maine has completed a similar state-specific study of background concentrations (PDF) in non-agricultural urban and non-urban soils with similar results. Please contact Maine DEP for guidance on interpreting background PFAS concentrations in Maine.

Other sources of PFAS to soil include irrigation water, aerial deposition, and potentially even rainwater. If PFAS have found their way to groundwater, irrigation water pumped from a drilled or dug well may be contaminated, and the PFAS from that contaminated water may build up in the irrigated soil over time. There are also a few documented cases of elevated levels of PFAS in soils in the vicinity of manufacturing facilities that used PFAS in their processes, including in southern New Hampshire, southwestern Vermont, and upstate New York. These elevated levels are believed to be due to deposition of airborne PFAS compounds. Rainwater may also be a factor contributing to what would be considered low, “background” levels of PFAS on fields that may have never received any sludge or septage. Groundwater can also be impacted by sources other than sludge/septage spreading, such as leaking residential septic systems.

This work is supported by the USDA National Institute of Food and Agriculture, Farm and Ranch Stress Assistance Network (FRSAN) project 2019-70028-30464 and 2020-70028-32729.

Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S Government determination or policy.

Appendices

Appendix A: Links to Important Resources

PFAS Navigator Program

  • The PFAS Navigator Program is a confidential and no-cost program to help farmers impacted by PFAS access resources and support, funded by DACF’s PFAS Fund and operated by UMaine Extension.
  • Contact options:

Maine Department of Agriculture, Conservation and Forestry

Online resources:

  • DACF PFAS website – Information on DACF’s PFAS response, direct financial and technical assistance programs for impacted farmers, and the PFAS Fund. Also includes factsheets for livestock and forage producers.

Contacts:

Maine Department of Environmental Protection

Online resources:

Contacts:

  • To contact Maine DEP regarding any questions related to PFAS, email PFAS.DEP@maine.gov or call 207.287.5842.

Maine Center for Disease Control and Prevention

Online resources:

  • PFOS, PFOA and Other PFAS: Questions and Answers Fact Sheet (PDF)
  • Laboratories in Maine that Conduct Residential PFAS Analysis for Water and Soil – This link takes you to the Maine Laboratory Accreditation webpage. Under “Listings,” see “Labs Accredited in Maine to Test for PFAS in Drinking Water” (list is updated regularly)

Contact:

  • For questions about PFOS, PFOA or other PFAS in the environment, blood testing, or health effects, contact the Maine CDC at 866.292.3474 (toll-free in Maine), 207.287.4311, or Maine Relay 711 and ask to speak to a toxicologist.

U.S.D.A. Farm Service Agency, Maine

  • Administers the USDA Dairy Indemnity Payment Program (DIPP)
  • Overall FSA Contact – Lucia Brown, Deputy State Executive Director, lucia.brown@usda.gov

University of Maine Cooperative Extension

Online resources:

Contact:

Maine Organic Farmers and Gardeners Association

Online Resources:

Contacts:

  • Ryan Dennett, Programs Director: rdennett@mofga.org or 207.568.4121; For questions about financial or technical assistance, testing or results, including development of mitigation strategies.
  • Caleb Goossen, Crop Production and Conservation Specialist: cgoossen@mofga.org or 207.568.6029; For questions about research, the chemistry of PFAS, etc.

Maine Farmland Trust

Online resources:

Contact:

Appendix B: Historical Spreading Data Available from Maine DEP

A general note regarding use of the “Maine DEP PFAS Investigation” Online Map: This mapping tool is under development and is continuing to be updated as more information is gathered. In some cases, the map shows sites that were licensed for spreading, but which never received any material. In other cases, sites that were land-applied with residual materials may not be indicated on the map. The DEP welcomes any information from citizens that can help them continue to improve their data. Landowners can contact PFAS.DEP@maine.gov with questions, corrections, or other information related to the map data.

Another important caveat: This map will only show sites that have been licensed for the land application of Class B biosolids. Class A biosolids do not require a site-specific license, and therefore could be spread anywhere, and records were not required to be kept for Class A spreading events. The historical information provided by the map is helpful in piecing together the history of a property, but in many cases may not reflect the full history of biosolids application on any given property.

There are two important resources to be used in tandem if you want to find out whether a piece of land has a history as a biosolids land application site: the Maine DEP PFAS Investigation map, and the DEP’s historical land application records.

1. Maine DEP PFAS Investigation Map

Visit the map.

You can type an address into the search box to go to a specific location and see whether the site is marked with the symbol for “sludge utilization site” or “septage land application site”:

Screenshot of icons showing Sludge Utilization Site and Septage Land Application Site for PFAS maps

If your land has one of these symbols, you click on the symbol to get more information about the site. The description will give you basic details about the site history, including the source of the material, but will not include details such as how much material was applied. If you want to learn how much material was applied, the application year, the source, and exactly where it was applied, you’ll need to dig further in the publicly available spreadsheet described below.

In addition to providing information about historical land application of residual materials, the map also shows test results for soil and water samples collected by Maine DEP. These test results were previously reported in the DEP PFAS Data Map, which has been discontinued.

2. DEP spreadsheet titled 2020-11-12-sludge-bioash-land-application (Excel), Maine.gov

Note: This spreadsheet represents the best information DEP had in November 2020. The spreadsheet has continued to be updated with corrections since then, but the most updated version is not publically available at this time.

  1. To find spreading information for your land base, obtain the following data from the Maine EGAD Site Types map:
    1. Site Name(s)
    2. Licensee(s) (the producers of the residual material…usually a municipal wastewater treatment facility)
  2. Open the spreadsheet and click on the tab labeled “All Spreading Activities.” Use the Find function (CTRL + F) to search for your site name. Click through all of the entries for the site, taking note of the names of all of the Licensees (treatment facilities) associated with the site.
  3. There is a spreadsheet tab for each licensed producer of biosolids. For each Licensee associated with your land:
    1. Open the spreadsheet tab for that Licensee.
    2. Under the heading “Licensed Land Application Sites,” find your site name. Take note of the license #, which can be helpful when requesting records from DEP. Also double-check that the town is correct.
    3. Scroll down further in the spreadsheet, to the heading “Spreading Activities (as reported in annual reports).” Here you’ll find each spreading activity that was reported, including the volume spread. Again, using the “Find” function is helpful to locate all the records for your site. Recommend copying and pasting the entries pertinent to your farm into a separate spreadsheet for your records.
    4. Repeat this process for each entity that was licensed to land-apply on your land to determine the total amount applied. Note that in many cases, a single site may have been further subdivided into smaller fields. The names of these smaller subsections may or may not be noted on the Maine EGAD Site Types map. If they are not, it is hard to know exactly how much material was spread and where. See below for further instructions on obtaining more detailed site maps.

3. Obtaining Site Maps

It is often necessary to obtain site-specific maps, which include field names that correspond to the spreading records from the spreadsheet mentioned above. To obtain these specific maps, you can email Maine DEP at pfas.dep@maine.gov to request site-specific info such as maps or the original application file.

Appendix C: Acronyms Used in this Document

  • CDC – Maine Center for Disease Control & Prevention. The Maine CDC is an office of the Maine Department of Health and Human Services
  • DACF – Maine Department of Agriculture, Conservation and Forestry
  • DEP – Maine Department of Environmental Protection
  • EPA – U.S. Environmental Protection Agency
  • FSA – U.S.D.A. Farm Service Agency
  • MFT – Maine Farmland Trust
  • MOFGA – Maine Organic Farmers and Gardeners Association
  • PFAS – Per- and poly-fluoroalkyl substances
  • UMaine – University of Maine

Specific PFAS compounds:

  • PFOS – Perfluorooctane sulfonic acid
  • PFOA – Perfluorooctanoic acid
  • PFHpA – Perfluoroheptanoic acid
  • PFNA – Perfluorononanoic acid
  • PFHxS – Perfluorohexane sulfonate
  • PFDA – Perfluorodecanoic acid
  • HFPO-DA – Hexafluoropropylene oxide dimer acid

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