Aside from drinking water, PFAS are also commonly found in soil and can get into plants that are grown in them. This guide will discuss how PFAS can get into your soil, how soil testing and remediation or treatment are done, and the health impacts of eating contaminated garden produce.
- PFAS soil testing methods are site-specific and hiring a certified professional to sample and test for PFAS in your soil ensures accurate and useful results.
- Among the treatment technologies that can be used to remove PFAS from soil are immobilization (stabilization), excavation and disposal, and thermal treatment (incineration).
- PFAS can accumulate in plants grown in PFAS-contaminated soil and increase your risk of exposure.
- Irrigation water containing PFAS can also contaminate the soil.
- Drinking PFAS-contaminated water poses a higher risk of exposure compared to eating garden produce grown in PFAS-containing soil.
What are PFAS?
PFAS (per- and polyfluoroalkyl substances) refer to various man-made chemicals used in industrial and household products since the 1940s. They are common in products that are resistant to heat, water, grease, and oil. For instance, you can find PFAS in non-stick cookware, stain-resistant clothes and carpets, food packaging, cosmetics, and others.
Sources of PFAS in Soil: How Do PFAS Get Into Your Garden?
Environmental releases from manufacturing facilities that use PFAS are the main causes of contamination both in soil and water. Air emissions, spills, and waste including wastewater can impact the soil and water sources at release points and surrounding areas. This can affect the plants that are grown in your garden.
PFAS can also enter soil when you use:
- PFAS-contaminated water
- Industrial sludges and ashes
- Manure from PFAS-exposed animals
What to Know About PFAS Soil Testing: How is Testing for PFAS in Soil Done?
It is crucial that you hire a certified professional to collect samples that are representative of your entire property or garden area to ensure useful and accurate test results.
EPA developed three analysis methods for PFAS in drinking water (Method 533, Method 537.1, and Method 537). However, there are no available methods for testing non-drinking water samples including soil that are nationally approved yet. The American Society for Testing and Materials (ASTM) did provide one method for testing Perfluorinated Chemicals (PFCs) including PFAS in soil namely ASTM D7968.
Can You Test Soil for PFAS Yourself?
We highly encourage homeowners to leave PFAS sampling and testing in the soil to environmental professionals to ensure useful results. But if you want to take samples yourself, contact your local area for guidelines on how to collect soil samples properly and submit them to a certified laboratory for testing.
Before you take your own soil samples, take note of the following to avoid contaminating your samples:
- Use sample collection tools (e.g. trowels, shovels, bowls, augers) that are PFAS-free
- Wear PPE and proper clothing (use clothing that does not contain any PFAS material)
- Do not use personal care products that might contain PFAS
- Ensure that the sample area is free from PFAS-containing materials (e.g. wrapped snacks or food that may be using PFAS packaging)
Also, the best sampling method will depend on the area’s intended use, geography, environment, and other specific needs.
Professionals use certain types of field clothing, PPE, and sampling tools when collecting soil samples. They take precautions by making sure that all of the materials they use and bring to the site area are free from PFAS to prevent cross-contamination and guarantee site-specific results. They also know where and how many samples to collect.
Thus, hiring a certified PFAS testing professional is important.
PFAS Soil Remediation & Contamination Treatment Methods: How Do You Get PFAS Out of the Soil?
If the presence of PFAS in your soil has been confirmed after testing, site-specific remediation or treatment should be done by experienced professionals. Take note that PFAS treatment technologies are still evolving.
The most suitable remediation or treatment method will depend on:
- Characteristics of PFAS and changes in their properties
- The extent of the contamination
- Presence of co-contaminants
- Regulatory compliance applicable in your area
3 Treatment Technologies for PFAS in Soil
Among the treatment technologies that can be performed to remove, immobilize, or destroy PFAS in soil include the following:
#1 Immobilization Technologies
Sorption and stabilization technologies are considered chemical fixation or immobilization technologies. They are affordable, fast, and non-destructive methods to reduce leaching from soil. However, they only immobilize or bind PFAS and do not destroy them.
#2 Excavation & Off-Site Disposal
This method treats PFAS-impacted soil by removing them for disposal at permitted landfills. After excavation, the area is filled with backfill. To reduce leaching further, stabilization is recommended before backfilling. Excavated soil can also be treated through stabilization or incineration before disposal.
#3 Thermal Treatment
Thermal treatment through incineration involves destroying PFAS chemicals by applying heat to PFAS-impacted soil. However, research is still ongoing about the effectiveness and safety of PFAS incineration. Moreover, byproducts from the incineration of PFAS can be released into the environment and cause secondary soil and air pollution.
What Home Gardeners Should Know About PFAS in Soil
If you are growing plants in your backyard garden and PFAS contamination is a concern in your area, keep in mind that your plants can take up PFAS chemicals from contaminated soil or irrigation water.
However, more research is still needed to determine how much PFAS will specific crops take up.
This will depend on various factors such as:
- PFAS concentration in the soil and/or water
- Type of plant
- Type of PFAS (i.e.shorter-chain PFAS like PFPeA and PFBA tend to accumulate in the plant’s edible parts while longer-chain PFAS like PFOA and PFOS tend to stay in the roots)
- Type of soil and its properties
- Other components in the soil
Tips to Lower Levels of PFAS in Homegrown Produce
Follow the tips below to reduce your plants’ uptake of PFAS chemicals and minimize your exposure:
- Use filtered water or rainwater to water your garden
- Wash garden produce, remove outer leaves, or peel them before eating
- Use manure and compost or other natural matter
- Use clean soil (topsoil) and create raised garden beds
- Wear gloves when gardening and wash your hands after
- Be careful not to bring dirt from your garden to your house
Health Impacts of PFAS in Soil: PFAS Exposure Through Eating Garden Plants
Research is also underway to better understand the health effects associated with low levels of exposure to PFAS over long periods of time, especially in children. – EPA, Our Current Understanding of the Human Health and Environmental Risks of PFAS
Although research is still ongoing about the impacts of different levels of exposure to PFAS on health, current scientific studies did reveal that certain types of PFAS can cause adverse health effects. Also, safe levels of PFAS in garden produce that people can eat are still being studied.
Moreover, occasional consumption of plants grown in PFAS-contaminated soil or irrigated with contaminated water only causes minor exposure. Drinking water that is contaminated with high PFAS levels regularly poses a higher risk of exposure. In fact, drinking water is the major source of exposure to PFAS in communities.
But since people can be exposed to PFAS from various sources, long-term and repeated exposure can cause the chemicals to accumulate in the body. Thus, we recommend minimizing your exposure as much as possible.
Note: We recommend having your drinking water tested if you live near areas that are known to be contaminated with PFAS.
PFAS remediation and treatment can be done through immobilization, excavation and off-site disposal, or thermal treatment technologies. The ideal remediation/treatment method will depend on the site’s specific needs.
You can take samples yourself by following PFAS sampling guidelines provided in your local area, but we highly recommend hiring an experienced professional to do the job for you. Also, you can do the sampling yourself, but testing must be done by qualified professionals in a laboratory that is certified to test for PFAS.
Studies have shown that PFAS may alter the soil’s properties and significantly increase soil pH and litter decomposition as well as decrease respiration. PFAS in the soul can also bioaccumulate in plants and, though minor, increase your risk of exposure.
PFAS in soil not only affects soil quality but can also be taken up by plants grown in them. Eating garden produce that has PFAS along with drinking PFAS-contaminated water over an extended period can lead to serious health conditions. Thus, minimizing your exposure by testing for PFAS in your soil is important.
RPF Environmental provides quality environmental testing services in the New England region and beyond at prices you can afford. Contact us now so our professionals can assist you with your specific needs!