While drinking water is the most widely discussed PFAS exposure route, contaminated irrigation water represents a significant and often underappreciated pathway through which PFAS enter the food supply. As agricultural areas near PFAS contamination sources — military bases, industrial facilities, and landfills — continue to use affected water for irrigation, the farm-to-table transfer of these chemicals warrants serious attention.
How PFAS Move From Water to Crops
Plants can take up PFAS from irrigation water through their root systems, with the degree of uptake varying significantly by:
- PFAS compound properties: Short-chain PFAS and those with carboxylate head groups tend to be more bioavailable to plants than long-chain sulfonates
- Plant species: Leafy vegetables (lettuce, spinach, kale) show higher PFAS accumulation than root vegetables or fruits; root vegetables show intermediate uptake
- Soil characteristics: Sandy, low-organic-matter soils retain less PFAS, allowing more to remain in soil water available for plant uptake; clay-rich soils with high organic matter bind PFAS more strongly
- PFAS concentration in irrigation water: Higher water concentrations drive higher plant tissue concentrations
Documented Cases of Agricultural PFAS Contamination
Several significant agricultural PFAS contamination events have been documented in the United States and internationally:
Fairfield, Maine (2016): Farms near a landfill that accepted industrial waste were found to have PFAS-contaminated irrigation water. Subsequent testing revealed PFAS in milk from dairy cows that had consumed contaminated water and feed — some of the highest documented PFAS levels in food in the US. Several farms were forced to cease operations.
Colorado Springs area: Farms irrigated with water from a creek receiving discharge from a nearby military base showed elevated PFAS in soil and crops. Colorado implemented one of the first agricultural water PFAS standards in response.
EU member states: Multiple European investigations have documented PFAS in vegetables from farms using biosolids (sewage sludge) as fertilizer — another route by which PFAS enter agricultural soil.
The Biosolids Problem
Biosolids — the solid material remaining after wastewater treatment — are widely used as agricultural fertilizer. Because wastewater treatment plants do not remove PFAS, biosolids are often heavily contaminated with these compounds. Application of PFAS-laden biosolids to agricultural land can contaminate both soil and the groundwater or surface water used for irrigation, creating a circular contamination pathway.
EPA data on biosolids PFAS contamination prompted the agency to develop biosolids management guidance, though comprehensive federal limits on PFAS in biosolids remain under development as of 2025.
Regulatory Response and Testing
The regulatory landscape for agricultural PFAS is evolving rapidly. Several states have implemented or are developing:
- PFAS testing requirements for irrigation water in affected areas
- Agricultural water quality standards for PFAS
- Biosolids application restrictions in areas of known contamination
- Compensation programs for farmers whose land or products have been contaminated
The FDA has been developing methods for testing PFAS in food and conducting market basket surveys to understand actual dietary exposure levels from the food supply.
Implications for Consumers
For most consumers, dietary PFAS intake from food is estimated to be lower than water-based exposure for those living in highly contaminated water areas. However, for people using PFAS-contaminated private wells or municipal water with low PFAS levels, food may represent a more significant relative contribution to total intake.
Practical steps for consumers concerned about food-based PFAS exposure include:
- Peeling root vegetables, which can reduce surface-associated PFAS
- Choosing organic produce from farms that do not use PFAS-contaminated irrigation water or biosolids
- Staying informed about local agricultural contamination events through state environmental agency reports
- Filtering drinking and cooking water with a certified reverse osmosis system to address the most controllable exposure route
The Research Gap
Despite growing awareness, significant data gaps remain regarding PFAS in the food supply. Comprehensive surveillance of PFAS in commonly consumed crops, standardized reporting requirements, and clear thresholds for agricultural water quality are all still developing. Until more robust regulatory frameworks are in place, consumers in areas with known PFAS contamination are wise to take a precautionary approach to both water and food exposure.