How to Manage PFAS Exposure at Commercial Sites

A PFAS finding can change the risk profile of a property long before it establishes a cleanup obligation. For a buyer, lender, developer, or operating owner, the question of how to manage PFAS exposure is not limited to whether a chemical was detected. It is whether PFAS may affect people, drinking water, site operations, permits, transaction value, or future closure strategy.

PFAS, often called per- and polyfluoroalkyl substances, are a large group of persistent chemicals used in many industrial, commercial, and consumer applications. Their persistence, mobility in groundwater, and evolving regulatory treatment make them materially different from many conventional contaminants. The appropriate response is not automatic, property-wide sampling. It is a focused, defensible process that identifies credible sources, evaluates exposure pathways, and supports business decisions without creating unnecessary delay or cost.

Start With a PFAS-Specific Conceptual Site Model

The most effective PFAS investigations begin before the first sample bottle is filled. A conceptual site model should identify where PFAS may have been used, released, transported, or received and who or what could be affected. For commercial and industrial properties, this means looking beyond the current operation.

Historical use is central. Fire training areas, aviation facilities, metal plating operations, textile and paper manufacturing, landfills, wastewater treatment systems, chemical storage areas, and locations where aqueous film-forming foam may have been stored or discharged can warrant closer evaluation. So can imported fill, biosolids application, recycled water use, and off-site migration from neighboring industrial or municipal sources.

The model should also account for hydrogeology and property setting. A release near a stormwater feature may behave differently from one at a dry industrial yard. Shallow groundwater, fractured bedrock, private wells, surface-water connections, and nearby municipal supply wells can all change the significance and urgency of a finding.

This initial work has practical value in a transaction. It helps distinguish a property with a documented historical PFAS use from one where PFAS concern is based only on a broad industry category. That distinction can affect the scope of diligence, the need for access agreements, the structure of indemnities, and the time required to reach a defensible closing decision.

How to Manage PFAS Exposure Through a Phased Process

PFAS risk should be managed in phases, with each decision informed by the last. A phased approach preserves flexibility and avoids treating a screening concern as a confirmed liability.

1. Identify likely sources and receptors

Review historical reports, aerial imagery, permits, fire suppression records, safety data sheets, waste manifests, utility information, interviews, and prior environmental sampling. The goal is to determine whether a plausible source exists and whether there are meaningful receptors, such as building occupants, on-site workers, nearby residents, private well users, surface water, or ecological resources.

For occupied properties, distinguish between environmental presence and actual exposure. PFAS detected in soil or groundwater does not necessarily mean people are being exposed. Exposure depends on the pathway. Drinking water use, vapor or dust considerations where applicable, direct contact, irrigation, food production, and migration to surface water should be evaluated based on site conditions rather than assumed.

2. Develop a targeted sampling plan

If the conceptual model supports further action, sampling should be designed around specific questions: Is PFAS present at a suspected source area? Has it affected groundwater? Is it moving off site? Does it affect a potable water supply or discharge point?

PFAS sampling requires careful field controls. Many common materials and products can introduce cross-contamination concerns, including certain waterproof clothing, food packaging, personal care products, tubing, and field supplies. A sampling plan should define acceptable materials, field blanks, equipment decontamination procedures, laboratory methods, reporting limits, and chain-of-custody requirements before mobilization.

The laboratory method and analyte list should align with the decision at hand and the applicable state or federal program. A broad analytical list may be useful for source characterization, while a narrower list may be appropriate for compliance monitoring. The right scope depends on the property history, regulatory setting, and the need to compare results with current screening levels, drinking water standards, permit conditions, or cleanup criteria.

3. Evaluate results in their regulatory and business context

A laboratory result is not a risk conclusion. PFAS standards and guidance vary by jurisdiction, medium, and program, and they continue to evolve. Results should be assessed against the requirements that actually apply to the property, not simply the lowest available screening value from another program or state.

For example, drinking water concerns may require immediate attention where a private well or active potable supply is involved. A groundwater detection at a non-potable industrial site may instead call for delineation, monitoring, source control, or a review of future land-use restrictions. The difference matters when estimating cost, negotiating a purchase agreement, or communicating with a regulator.

Decision-makers should also assess the data quality. Unexpected detections, inconsistent field blanks, elevated reporting limits, or samples collected without appropriate PFAS controls can limit the defensibility of a result. In some cases, a carefully designed confirmation event is more valuable than prematurely expanding an investigation.

4. Control credible exposure pathways promptly

When an active exposure pathway is identified, interim measures should not wait for a full remediation design. The appropriate measure depends on the receptor and medium. It may include providing an alternate water source, removing a private well from service, installing treatment, modifying water-use practices, securing a source area, or managing impacted water during construction dewatering.

At active industrial sites, operational controls can be equally important. Review fire suppression systems and emergency response procedures, particularly where legacy foam may be present. Establish protocols for storage, replacement, discharge prevention, and waste handling. If construction is planned, incorporate PFAS considerations into soil management plans, groundwater handling procedures, worker protection planning, and disposal profiling.

Interim controls should be documented clearly. They demonstrate that the owner recognized and managed a credible risk while additional delineation or agency coordination proceeds.

5. Build a remediation and liability strategy proportionate to the risk

PFAS remediation is rarely a single-technology exercise. Source removal or containment may be appropriate in some settings, while groundwater extraction and treatment, granular activated carbon, ion exchange, membrane systems, monitored attenuation of downgradient concentrations, or institutional controls may be considered in others. Technology selection depends on PFAS chemistry, concentrations, groundwater conditions, flow rates, waste management options, and the cleanup objective.

Treatment creates its own obligations. Spent media, concentrated residuals, and treatment byproducts must be managed through a legally and technically sound disposal pathway. A remedy that merely transfers PFAS from water to a difficult-to-manage residual stream is not a complete risk strategy.

For transactions and redevelopment, the liability strategy should move alongside the technical strategy. Parties may need to define responsibility for investigation costs, agency communications, access, corrective action, third-party claims, and future changes in regulatory standards. Environmental insurance, indemnities, escrow arrangements, and price adjustments can all have a role, but none substitutes for a clear understanding of the site condition.

Align Diligence With the Property Decision

PFAS should be integrated into, not separated from, broader environmental due diligence. A Phase I Environmental Site Assessment may identify recognized environmental conditions associated with historical uses, but it may not answer PFAS-specific questions without further records review or targeted investigation. The need for additional work depends on the property's history, intended use, financing requirements, and the consequence of being wrong.

A lender financing an industrial acquisition may need a concise risk assessment that identifies likely sources, data gaps, and a realistic path to control. A developer considering residential conversion may require a more conservative evaluation of groundwater, imported fill, nearby supply wells, and long-term land-use controls. An owner facing a permit renewal may need to focus first on discharge streams, wastewater residuals, and operational practices.

This is where speed and technical judgment matter. Over-scoping can delay a deal and create data with no decision value. Under-scoping can leave a buyer with an unpriced liability or an unworkable redevelopment plan. The most useful scope is one tied directly to the property decision, the likely regulatory pathway, and the available risk-transfer options.

Maintain Records That Support Defensible Decisions

PFAS matters can remain active for years, particularly where groundwater migration, changing standards, or multi-party source questions are involved. Maintain a clear record of the conceptual site model, sampling rationale, field procedures, laboratory reports, communications, exposure-control decisions, and regulatory correspondence.

For owners with multiple facilities, consistency is especially valuable. A portfolio-level screening framework can prioritize locations based on industry history, firefighting foam use, proximity to water supplies, known releases, and regulatory attention. It should not replace site-specific analysis, but it can help direct capital toward the highest-consequence locations.

The strongest PFAS strategy is not the one that generates the most data. It is the one that answers the next material question, protects people where a credible pathway exists, and gives the business a clear basis for action. For high-stakes properties, experienced environmental counsel and senior technical oversight can turn an uncertain PFAS concern into a manageable project decision.