Consensus Study Report

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This study was supported by a grant agreement between the National Academy of Sciences and the U.S. Department of Agriculture–Natural Resources Conservation Service. This material is based upon work supported by the U.S. Department of Agriculture, under agreement number NR243A750008G004. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author and do not necessarily reflect the views of the U.S. Department of Agriculture. In addition, any reference to specific brands or types of products or services does not constitute or imply an endorsement by the U.S. Department of Agriculture for those products or services.

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Cover photo: “Avoca Terraces” by Jason Johnson, Iowa Natural Resources Conservation Service.

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Digital Object Identifier: https://doi.org/10.17226/29272
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Suggested citation: National Academies of Sciences, Engineering, and Medicine. 2026. PFAS in Agricultural Systems: Guidance for Conservation Programs at USDA. Washington, DC: National Academies Press. https://doi.org/10.17226/29272.

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COMMITTEE ON ASSISTANCE TO THE U.S. DEPARTMENT OF AGRICULTURE IN BUILDING A FRAMEWORK FOR ADDRESSING PFAS ON AGRICULTURAL LAND

JIM IPPOLITO (Chair), The Ohio State University

THOMAS W. CHRISTENSEN, Ecosystem Services Exchange

JACQUELINE MACDONALD GIBSON, North Carolina State University

BENJAMIN M. GRAMIG, U.S. Department of Agriculture–Economic Research Service

JENNIFER L. GUELFO, Texas Tech University

LINDA S. LEE, Purdue University

HUI LI, Michigan State University

ELLEN B. MALLORY, University of Maine

TIMOTHY ROSEN, ShoreRivers

Study Staff

KARA N. LANEY, Study Director

ROBERTA SCHOEN, Board Director

ELIZABETH BARKSDALE BOYLE, Senior Program Officer

MITCHELL HEBNER, Research Associate

SAMANTHA SISANACHANDENG, Senior Program Assistant (until April 2025)

ANNIE MANVILLE, Senior Program Assistant (as of April 2025)

Reviewers

This Consensus Study Report was reviewed in draft form by individuals chosen for their diverse perspectives and technical expertise. The purpose of this independent review is to provide candid and critical comments that will assist the National Academies of Sciences, Engineering, and Medicine in making each published report as sound as possible and to ensure that it meets the institutional standards for quality, objectivity, evidence, and responsiveness to the study charge. The review comments and draft manuscript remain confidential to protect the integrity of the deliberative process.

We thank the following individuals for their review of this report:

Although the reviewers listed above provided many constructive comments and suggestions, they were not asked to endorse the conclusions or recommendations of this

Acknowledgments

The committee and staff thank the sponsor of this study—the U.S. Department of Agriculture’s Natural Resources Conservation Service—for the opportunity to contribute to solving an urgent problem. They are also grateful for the support of the National Academies of Sciences, Engineering, and Medicine’s staff who contributed to producing this report: Eric Edkin and Lori Brenig with the Center for Health, People, and Places; Lauren Everett, Radiah Rose, and Elisabeth Reese in the Office of Peer Review; Cynthia Getner in the Office of the Chief Financial Officer; Douglas Sprunger, Beth Ewoldsen, Kimberly Halperin, Reece Meyhoefer, and Solomon Self in the Office of the Chief Communications Officer; and Tucker Nelson in the Office of Congressional and Government Affairs. They would also like to thank copyeditors Danielle Nasenbeny and Allison Boman.

Contents

PREFACE

ACRONYMS AND ABBREVIATIONS

SUMMARY

PFAS in Agricultural Systems

Federal Conservation Support and PFAS in Agricultural Systems

Decision-Making Under Uncertainty

Applied Research Gaps

1 INTRODUCTION

The Committee’s Charge and Process

Study Scope and Report Organization

References

2 PFAS IN AGRICULTURAL SYSTEMS

PFAS Structure

Occurrence of PFAS in U.S. Soils

Fate and Transport of PFAS in the Environment

Entry and Cycling of PFAS in Agricultural Systems

Scope of the Challenge

References

3 FEDERAL CONSERVATION SUPPORT AND PFAS IN AGRICULTURAL SYSTEMS

Conservation Agencies, Customers, and Goals

Conservation Planning, Resource Concerns, and Conservation Practices

Conservation Programs

Programs, Practices, and PFAS

Opportunities to Address PFAS Concerns Through Conservation Support

References

4 DECISION-MAKING UNDER UNCERTAINTY

Identifying PFAS of Concern on Agricultural Land

Identifying Agricultural Lands at Risk from PFAS in the Absence of Site-Specific Data

Initial Framework for Decision-Making

References

5 APPLIED RESEARCH GAPS FOR PFAS MANAGEMENT IN THE CONTEXT OF CONSERVATION

Discerning PFAS Fate and Transport in Varying Soil Types Across the United States

Opportunities to Trap or Sequester PFAS

Understanding Plant Characteristics that Affect PFAS Uptake and Accumulation

PFAS Mitigation in Livestock

References

APPENDIXES

A Committee Member Biographical Sketches

B Public Meeting Agendas

C PFAS Family Tree

D Potentially PFAS-Relevant Conservation Practices

E PFAS-Relevant Resource Concerns, Effects, and Rationale for Nine Conservation Practices

Boxes, Figures, and Tables

BOXES

1-1 Statement of Task

2-1 Legacy PFAS: PFOA and PFOS

2-2 PFAS and Persistence

2-3 Organic Soil Amendments

3-1 Conservation Technical Assistance

3-2 On-Farm Conservation Innovation Trials

4-1 Modeling PFAS Fate and Transport

4-2 Predicting Where PFAS Will Occur: From Mechanistic Models to Machine Learning

4-3 USDA’s Web Soil Survey

5-1 Fate, Transport, and Climate

5-2 PFAS Site Index

FIGURES

S-1 Conceptual model of the entry and cycling of PFAS on agricultural land

S-2 Framework for conservation planning and practice implementation to address PFAS concerns, accounting for uncertainty

2-1 General structure example of neutral, non-polymeric, perfluorinated PFAS

2-2 PFAS family tree

2-3 PFAS chain length in relation to carbon number, solubility, volatility, adsorption, bioaccumulation, and toxicity

2-4 Depiction of microbially mediated transformation for two representative precursors, (A) fluorotelomerization example of 8:2 fluorotelomer phosphate diester (diPAP) transformation to PFCAs with PFOA as dominant and (B) electrochemical fluorination example of N-ethyl perfluorooctane sulfonamide (EtFOSA, sulfluramid) transformation to PFOS

2-5 Possible sorption behaviors of PFAS in the soil environments, an example of anionic perfluoroalkyl acids (PFAAs)

2-6 Conceptual model of the entry and cycling of PFAS on agricultural land

2-7 Potential introduction and on-farm cycling of PFAS through different media

2-8 PFAS detected in drinking water, environmental media, reported discharges and greenhouse gas emissions, as well as locations of military installations, PFAS spills or release events, Superfund sites with PFAS detections, and PFAS manufacturing facilities in the contiguous United States

3-1 Natural Resources Conservation Service’s Nine-Step Conservation Planning Process

4-1 Risks of the occurrence of four short-chain PFAS in groundwater in the Minneapolis/St. Paul East Metro area at concentrations above the state’s health advisory concentration

4-2 Probability of detection of any PFAS in groundwater at depths used for drinking water

4-3 Framework for conservation planning and practice implementation to address PFAS concerns, accounting for uncertainty

4-4 PFAS attenuation by 30-meter soil map unit

5-1 (a) PFBA and PFOA removal efficiencies exhibited by biochars synthesized with different feedstock materials in comparison with granular activated carbon and anion exchange resin; (b) PFBA and PFOA removal efficiencies exhibited by reed straw–derived biochars synthesized at different pyrolysis temperatures; (c) PFBA and PFOA removal efficiencies exhibited by reed straw–derived biochars pyrolyzed at 900 °C for different durations

5-2 Factors (pH, temperature, competing ions, natural organic matter, ionic strength) affecting PFAS removal by clay-based adsorbents

C-1 Family tree of PFAS

TABLES

2-1 Maximum Reported PFAS in Soils Worldwide and in the United States

3-1 National Resource Concern List

3-2 Potential Positive and Negative Impacts of Conservation Practices on PFAS Contamination of Agricultural Lands

3-3 PFAS-Relevant Resource Concerns

3-4 NRCS Conservation Programs and Their Potential to Mitigate PFAS Concerns on Agricultural Lands Based on Current Program Legislation and Regulation

4-1 Commonly Referenced Definitions of Per- and Polyfluoroalkyl Substances (PFAS)

4-2 Definitions of Persistence, Bioaccumulation, Toxicity, and Mobility by the European Union Registration, Evaluation, Authorization and Restriction of Chemicals

4-3 Representative Datasets Used in Data-Driven Approaches for Predicting PFAS Occurrence in the Environment

5-1 Factors that Impact Sorption of PFCAs and PFSAs on Soil

5-2 Physical and Chemical Properties of Clay-based Adsorbents for PFAS Removal

D-1 Potentially PFAS-Relevant Practices

E-1 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Cover Crop Practice Standard 340

E-2 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Nutrient Management Practice Standard 590

E-3 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Pasture and Hay Planting Practice Standard 512

E-4 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Grazing Management Practice Standard 528

E-5 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Soil Carbon Amendment Practice Standard 336

E-6 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Tree and Shrub Establishment Practice Standard 612

E-7 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Upland Wildlife Habitat Management Practice Standard 645

E-8 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Water and Sediment Control Basin Practice Standard 638

E-9 PFAS-Relevant Resource Concerns, Effects, and Rationale for Using Watering Facility Practice Standard 614

Preface

The daunting task of providing technical assistance to land managers on more than 1 billion acres of privately owned farm, ranch, and forested lands falls upon personnel within the Natural Resources Conservation Service (NRCS) of the U.S. Department of Agriculture (USDA). Utilizing a suite of programs and practices to help landowners protect precious natural resources, USDA–NRCS supports science-based land uses and management that fit the limits of economic practicality. For working lands, this approach focuses on agricultural production along with conservation, while for sensitive lands (e.g., wetlands) the approach is protection and restoration. The programs and practices currently utilized by the agency help target a myriad of challenges (e.g., nutrient, residue, and tillage management; contour farming; wetland reclamation) that are common to many who depend on these lands for their livelihoods.

Per- and polyfluoroalkyl substances (PFAS) contamination within working lands is a new challenge faced by federal conservation agencies. PFAS are an extensive suite of anthropogenic organic compounds containing perfluorinated moieties that, once released into the environment, are persistent, span the spectrum of mobility, fate, and transport, and may be linked to potential health effects. Because of their widespread use in everyday products and in products that help save lives (e.g., firefighting foams), in conjunction with their varied fate and transport mechanisms, PFAS can be found within all four corners of the globe. PFAS have been detected in pristine locations such as Antarctic snow, ice, and seawater. U.S. working lands might also contain PFAS; thus, means for addressing PFAS within the programs and practices to protect natural resources are warranted.

The task of characterizing the scope of PFAS challenges across working lands and understanding the capabilities (and their unique pros and cons) of conservation programs, practices, and initiatives to address PFAS contamination and mitigation via practical approaches were not inconsequential topics to address. Committee members,

Acronyms and Abbreviations