{"id":14812,"date":"2026-01-30T12:46:27","date_gmt":"2026-01-30T11:46:27","guid":{"rendered":"https:\/\/www.litoclean.com\/?p=14812"},"modified":"2026-01-30T12:54:11","modified_gmt":"2026-01-30T11:54:11","slug":"pfas-soil-groundwater","status":"publish","type":"post","link":"https:\/\/www.litoclean.com\/en\/blog\/pfas-soil-groundwater\/","title":{"rendered":"PFAS in soil and groundwater: what are they, why do they matter, how are they tested, and what does their remediation really look like"},"content":{"rendered":"\n<p><\/p>\n\n\n\n<p>PFAS (per- and polyfluoroalkyl substances) are a large family of synthetic chemicals used for decades because they repel water, grease, and heat. The problem is that many PFAS are <strong>highly persistent<\/strong> in the environment and can migrate from soil into groundwater and surface waters\u2014often creating long-term liabilities for industrial sites, airports, landfills, training grounds, and any location linked to PFAS-containing products (notably firefighting foams).&nbsp;<\/p>\n\n\n\n<p>This article explains <strong>what PFAS are<\/strong>, <strong>where they come from<\/strong>, <strong>how to figure out a sampling plan<\/strong>, and <strong>which remediation pathways are realistic<\/strong>.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>What exactly are PFAS?<\/strong><\/h2>\n\n\n\n<p>PFAS is an umbrella term for thousands of fluorinated chemicals. Many are \u201csurfactant-like,\u201d which means they can move in water and interact with soils and organic matter in different ways. Their carbon\u2013fluorine bonds are extremely stable, which contributes to their <strong>persistence<\/strong> and why they\u2019re often called \u201cforever chemicals\u201d&nbsp;due the difficulty of their treatment.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Why PFAS are so hard to manage<\/strong>?<\/h3>\n\n\n\n<p>PFAS challenges rarely come from one single issue\u2014it\u2019s the combination:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Many compounds, different behavior<\/strong>: some bind to soil, others travel fast in groundwater<\/li>\n\n\n\n<li><strong>Low regulatory thresholds in some jurisdictions<\/strong>: especially drinking water<\/li>\n\n\n\n<li><strong>Analytical complexity<\/strong>: avoiding contamination and selecting the right lab method<\/li>\n\n\n\n<li><strong>Remediation tradeoffs:<\/strong> capturing PFAS is easier than destroying PFAS (and so far the most applied techniques); destruction options can be expensive and high energy consumption<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Common PFAS sources and pathways (soil \u2192 groundwater)<\/strong><\/h2>\n\n\n\n<p>Most PFAS investigations begin with identifying potential source categories such as:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>AFFF firefighting foam use<\/strong>: airports, industrial sites, training areas. Even the fact that they have been banned for years<\/li>\n\n\n\n<li><strong>Industrial facilities<\/strong>: chemical manufacturing, metal plating, textiles, paper\/packaging<\/li>\n\n\n\n<li><strong>Landfills and waste handling<\/strong>: leachate can be a long-term source<\/li>\n\n\n\n<li><strong>Wastewater and biosolids<\/strong>: site-dependent, but important for some catchments<\/li>\n<\/ul>\n\n\n\n<p>From a conceptual site model standpoint, PFAS typically move through:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><strong>Surface release or historical disposal<\/strong><\/li>\n\n\n\n<li><strong>Retention in shallow soils<\/strong>: varies by PFAS type and soil properties<\/li>\n\n\n\n<li><strong>Leaching to groundwater<\/strong>: especially where infiltration is significant<\/li>\n\n\n\n<li><strong>Migration along groundwater flow paths<\/strong>: potentially to receptors like wells or surface waters<\/li>\n<\/ol>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>The regulatory context <\/strong><\/h2>\n\n\n\n<p>PFAS regulation is moving quickly, and the direction is consistent: <strong>more compounds, lower thresholds, more accountability.<\/strong><\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>United States: Drinking water standards (NPDWR)<\/strong><\/h3>\n\n\n\n<p>In April 2024, the US EPA finalized the first enforceable national drinking water regulation for PFAS. It set <strong>MCLs of 4 ppt<\/strong> for <strong>PFOA<\/strong> and <strong>PFOS<\/strong>, and <strong>10 ppt<\/strong> for <strong>PFNA, PFHxS, and HFPO-DA (GenX)<\/strong>, plus a <strong>Hazard Index<\/strong> approach for mixtures involving PFHxS, PFNA, HFPO-DA, and PFBS.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>EU: Restrictions and tightening controls<\/strong><\/h3>\n\n\n\n<p>In Europe, regulators are progressing toward broader restrictions and product controls on PFAS, with ongoing work under ECHA and additional targeted restrictions (for example, on PFAS in firefighting foams).&nbsp;<\/p>\n\n\n\n<p><strong>What this means for site owners\/operators:<\/strong> PFAS is increasingly treated as a <strong>long-tail environmental liability<\/strong>\u2014and sites that wait often end up reacting under tighter timelines and higher costs.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>How to test PFAS properly <\/strong><\/h2>\n\n\n\n<p>PFAS sampling fails most often for two reasons:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><strong>No site-specific sampling strategy<\/strong>: poor conceptual site model<\/li>\n\n\n\n<li><strong>Cross-contamination<\/strong>: during sampling\/handling<\/li>\n<\/ol>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 1: Build a PFAS-specific sampling plan<\/strong><\/h3>\n\n\n\n<p>A defensible plan typically defines:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Likely sources (AFFF areas, process areas, storage, waste zones)<\/li>\n\n\n\n<li>Target media (soil, groundwater, surface water, sediment, wastewater\u2014site dependent)<\/li>\n\n\n\n<li>Data Quality Objectives (screening vs compliance vs remedy design)<\/li>\n\n\n\n<li>QA\/QC approach (field blanks, trip blanks, duplicates, equipment blanks)<\/li>\n<\/ul>\n\n\n\n<p>The ITRC guidance emphasizes PFAS-specific sampling protocols and the need to prevent PFAS-containing materials from contacting samples (certain water-resistant coatings, etc.).&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 2: Choose analytical methods that match your matrix<\/strong><\/h3>\n\n\n\n<p>For <strong>non-potable waters, soils, biosolids, and tissues<\/strong>, EPA Method <strong>1633A<\/strong> (December 2024) supports multi-matrix PFAS analysis via LC-MS\/MS.&nbsp;<\/p>\n\n\n\n<p><strong>Tip:<\/strong> Don\u2019t let a lab \u201cpick a PFAS panel\u201d without aligning it to your site history and regulatory needs. The \u201cright\u201d list depends on known sources (AFFF vs industrial fluoropolymers), receptors, and jurisdiction.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Step 3: Interpret results with transport in mind<\/strong><\/h3>\n\n\n\n<p>PFAS results are not just numbers. For decision-making you typically want:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Spatial distribution (source zones vs plume)<\/li>\n\n\n\n<li>Vertical profiling (shallow vs deeper units)<\/li>\n\n\n\n<li>Trends over time (is the source still active?)<\/li>\n\n\n\n<li>Geochemistry\/soil properties (can influence partitioning and mobility)<\/li>\n<\/ul>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>PFAS remediation: multi-component instead of &#8220;silver bullet&#8221;<\/strong><\/h2>\n\n\n\n<p>PFAS remedies are usually designed around <strong>three goals<\/strong>:<\/p>\n\n\n\n<ol start=\"1\" class=\"wp-block-list\">\n<li><strong>Stop or reduce ongoing releases<\/strong> (source control)<\/li>\n\n\n\n<li><strong>Prevent exposure<\/strong> (risk management)<\/li>\n\n\n\n<li><strong>Reduce mass or plume<\/strong> (treatment\/removal)<\/li>\n<\/ol>\n\n\n\n<p>Because PFAS can be persistent and mobile, remedies are often <strong>multi-component<\/strong> rather than a single \u201csilver bullet.\u201d<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>1) Source control <\/strong><\/h3>\n\n\n\n<p>Before choosing a treatment technology, the fastest gains often come from:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li>Eliminating ongoing PFAS inputs (process change, foam management, waste controls)<\/li>\n\n\n\n<li>Controlling stormwater\/runoff pathways<\/li>\n\n\n\n<li>Isolating highly impacted soil \u201chot spots\u201d<\/li>\n\n\n\n<li>Managing landfill leachate or wastewater contributions (as applicable)<\/li>\n<\/ul>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>2) Ex-situ soil options <\/strong><\/h3>\n\n\n\n<p>Depending on site constraints and contaminant distribution:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Excavation + off-site disposal<\/strong> (effective for hot spots; needs disposal pathway and cost planning)<\/li>\n\n\n\n<li><strong>Soil washing\/separation<\/strong> (can reduce mass in some contexts)<\/li>\n\n\n\n<li><strong>Thermal treatment<\/strong> (site- and vendor-specific; requires careful evaluation of efficacy, emissions, and cost)<\/li>\n<\/ul>\n\n\n\n<p>Industry and guidance reviews emphasize that PFAS chemistry can make traditional soil remedies less effective and push projects toward integrated, site-specific strategies.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>3) Groundwater treatment <\/strong><\/h3>\n\n\n\n<p>Common approaches include:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Pump-and-treat<\/strong> with:\n<ul class=\"wp-block-list\">\n<li><strong>Collodial Activated Carbon (CAC)<\/strong><\/li>\n\n\n\n<li><strong>Ion Exchange (IX) resins<\/strong><\/li>\n\n\n\n<li><strong>Reverse osmosis \/ nanofiltration<\/strong> (high removal, but generates concentrate)<\/li>\n<\/ul>\n<\/li>\n\n\n\n<li><strong>Targeted hydraulic control<\/strong> near receptors (e.g., drinking water wells)<\/li>\n\n\n\n<li><strong>Emerging\/adjunct methods<\/strong> (site-specific): separation processes such as foam fractionation for certain matrices<\/li>\n<\/ul>\n\n\n\n<p>ITRC\u2019s PFAS guidance compares remediation approaches and highlights that treatment selection depends on matrix, PFAS types, concentration ranges, and waste management needs.&nbsp;<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>4) In-situ approaches <\/strong><\/h3>\n\n\n\n<p>In-situ remedies often focus on <strong>immobilization and flux reduction<\/strong> rather than \u201cdestruction,\u201d using sorbents or amendments designed to reduce PFAS mobility. Some projects also explore in-situ methods that enhance capture in impacted groundwater zones, depending on site conditions and regulatory acceptance.&nbsp;<\/p>\n\n\n\n<p><strong>Reality check:<\/strong> Many PFAS programs succeed by <strong>controlling migration<\/strong>, while long-term destruction strategies are evaluated in parallel.<\/p>\n\n\n\n<figure class=\"wp-block-pullquote\"><blockquote><p>Need a PFAS plan?<br>PFAS behaves differently in soil and groundwater, so effective programs start with a clear site model and an action plan for both media.<\/p><\/blockquote><\/figure>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>FAQ<\/strong><\/h2>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Are PFAS only a \u201cwater problem\u201d?<\/strong><\/h3>\n\n\n\n<p>No. Soil can store PFAS mass and act as a long-term source to groundwater. Many programs treat soil and groundwater together through the conceptual site model and remedy design.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>Can PFAS be fully removed from a site?<\/strong><\/h3>\n\n\n\n<p>It depends on site scale, PFAS types, and matrices. Hot spots may be removed; plumes can be controlled and treated; long-term management is often required.<\/p>\n\n\n\n<h3 class=\"wp-block-heading\"><strong>What\u2019s the biggest mistake companies make with PFAS?<\/strong><\/h3>\n\n\n\n<p>Starting with technology before establishing a PFAS-specific sampling program and a defensible conceptual site model.&nbsp;<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Next step: make PFAS manageable<\/strong><\/h2>\n\n\n\n<p>PFAS projects become manageable when you treat them like any other complex environmental issue: <strong>define the problem, get representative data, prioritize receptor protection, and choose remedies that match site reality<\/strong>\u2014not marketing claims.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>You may find these also interesting<\/strong><\/h2>\n\n\n\n<p><\/p>\n\n\n\n<blockquote class=\"wp-block-quote has-black-color has-text-color has-link-color wp-elements-8e21f73407947eef9ae582f1fde14e93 is-layout-flow wp-block-quote-is-layout-flow\">\n<p><a href=\"https:\/\/www.litoclean.com\/blog\/espana-necesita-un-marco-de-referencia-de-actuacion-para-pfas-en-suelos-y-aguas-subterraneas\/\">Espa\u00f1a necesita un marco de referencia de actuaci\u00f3n para PFAS en suelos y aguas subterr\u00e1neas &#8211; Litoclean<\/a><\/p>\n<\/blockquote>\n\n\n\n<blockquote class=\"wp-block-quote has-black-color has-text-color has-link-color wp-elements-a414dac80f7c0ef6774ae1f37c765a4f is-layout-flow wp-block-quote-is-layout-flow\">\n<p><a href=\"https:\/\/www.litoclean.com\/blog\/una-nueva-normativa-regulara-la-presencia-de-pfas-en-el-agua-de-consumo\/\">Una nueva normativa regular\u00e1 la presencia de PFAS en el agua de&nbsp;consumo &#8211; Litoclean<\/a><\/p>\n<\/blockquote>\n\n\n\n<h2 class=\"wp-block-heading\"><strong>Get to know the authors better<\/strong><\/h2>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-c521687c55dfa165bc4fecf24f90b58c\"><a href=\"https:\/\/www.linkedin.com\/in\/xavigarcia5\/\" target=\"_blank\" rel=\"noopener\">Xavi Garcia Sab\u00edn | LinkedIn<\/a> <\/p>\n\n\n\n<p class=\"has-black-color has-text-color has-link-color wp-elements-13ae66cc9c536ba08512f4438a9edb6d\"><a href=\"https:\/\/www.linkedin.com\/in\/sonia-baluk-72674523\/\" target=\"_blank\" rel=\"noopener\">Sonia Baluk | LinkedIn<\/a><\/p>\n\n\n\n<p><\/p>\n","protected":false},"excerpt":{"rendered":"<p>PFAS (per- and polyfluoroalkyl substances) are a large family of synthetic chemicals used for decades because they repel water, grease, and heat. The problem is that many PFAS are highly persistent in the environment and can migrate from soil into groundwater and surface waters\u2014often creating long-term liabilities for industrial sites, airports, landfills, training grounds, and [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":14835,"comment_status":"open","ping_status":"open","sticky":false,"template":"elementor_theme","format":"standard","meta":{"footnotes":""},"categories":[242,239],"tags":[],"class_list":["post-14812","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-soil-blog","category-water-blog"],"_links":{"self":[{"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/posts\/14812","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/comments?post=14812"}],"version-history":[{"count":6,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/posts\/14812\/revisions"}],"predecessor-version":[{"id":14837,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/posts\/14812\/revisions\/14837"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/media\/14835"}],"wp:attachment":[{"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/media?parent=14812"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/categories?post=14812"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.litoclean.com\/en\/wp-json\/wp\/v2\/tags?post=14812"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}