Part 2A & PFAS: Why you may be liable for contamination you didn't create

Published: 14 July 2026

Most industrial site operators are aware, in general terms, that they may have obligations for contamination associated with their own activities. Fewer are aware of the full extent to which Part 2A of the Environmental Protection Act 1990 can reach. Under the right circumstances, it can make you responsible for contamination you did not create, at a site you may not even have occupied when the contamination occurred.

As the UK's first PFAS Plan accelerates Part 2A enforcement activity, and as the Environment Agency prepares to publish its interactive map of high-risk sites, understanding how this liability mechanism works has become a practical necessity for anyone acquiring, occupying, developing or financing land with an industrial history.

How does Part 2A work?

The Part 2A contaminated land regime operates on a 'polluter pays' principle. Where land is identified as contaminated and posing an unacceptable risk to human health or the environment, local authorities are required to ensure it is remediated. The primary liability sits with the person who caused or knowingly permitted the contaminating substances to be present.

The complexity arises when that person cannot be found. If the original polluter has dissolved, gone into administration, or lacks the financial means to remediate, liability can transfer down a defined hierarchy. At the bottom of that hierarchy sits the current owner or occupier of the land – regardless of whether they caused the contamination, regardless of whether they knew about it when they acquired the site, and regardless of how long ago the contamination event occurred.

This is not a rare or isolated scenario. It represents the approach that will be applied at a significant number of PFAS-affected sites across England, where decades of industrial use by companies that no longer exist, or have changed ownership multiple times, have left contamination whose original authors are untraceable.

A recent example

In January 2025, Environment Agency sampling found PFOS contamination across 25 water sites. At one location, groundwater concentrations reached 3,840 nanograms per litre - orders of magnitude above any proposed safe threshold. The identified source was a facility where PFAS had been used historically in the manufacturing process. PFAS-contaminated material had also been spread on surrounding land.

The operator subsequently went into administration. Its assets, including the site, were sold to a new entity. That new entity, which acquired the site in a conventional commercial transaction and with no reason to expect a PFAS-specific liability, now faces potential regulatory engagement for a contamination problem it had no part in creating. Under Part 2A, that is a legally defensible outcome.

The February 2026 PFAS Plan commits to issuing new guidance to local authorities specifically on applying Part 2A to PFAS-contaminated sites. That guidance will clarify and, in practice, lower the threshold for formal enforcement action. Sites that were previously assessed as posing insufficient risk to warrant regulatory intervention may be reassessed against tightening standards.

The due diligence gap

The conventional Phase I environmental desktop study - the standard pre-acquisition due diligence tool - was designed primarily to identify contamination associated with a site's own historical use. It was not designed for PFAS. The questions it asks, the databases it searches, and the site history sources it consults do not automatically capture the full range of PFAS exposure pathways:

Atmospheric deposition from distant sources - PFAS precursor compounds that have travelled hundreds of kilometres in the atmosphere before depositing in rainfall.
Migration from adjacent sites - PFAS plumes in groundwater that originated at a neighbouring facility and have crossed the site boundary.
Biosolid application - historic spreading of PFAS-contaminated sewage sludge on agricultural land that now sits beneath or adjacent to a development site.
Indirect supply chain contamination - PFAS present in fire suppression systems, coatings or process chemicals installed by previous occupiers, without disclosure on material safety data sheets.

A site can be clean on its own historical use and still carry significant PFAS liability through any of these routes. Standard due diligence will not catch them without explicit PFAS-specific scoping.

What this means for transactions, financing and development

The transactional risk dimension of PFAS is already changing market practice. PFAS characterisation is now a standard item on the pre-acquisition environmental due diligence checklists of major commercial and industrial property buyers. Environmental warranties in sale and purchase agreements are being explicitly extended to cover PFAS. Where a vendor cannot demonstrate adequate characterisation of their site's PFAS position, buyers are seeking price adjustments, deferred completion, or specific indemnities.

For developers, the planning context is also evolving. PFAS risk is increasingly raised in planning applications involving brownfield land, and planning authorities are beginning to require PFAS-specific risk assessments as conditions of consent. The EA's forthcoming high-risk sites list will accelerate this.

For lenders and investors, PFAS liability is an emerging consideration in security valuation and ESG due diligence. A site carrying an uncharacterised PFAS liability is a site with an unquantified balance sheet exposure - precisely the kind of contingency that lending committees and ESG-mandated investors are becoming unwilling to underwrite.

The key question for any transaction or acquisition

Has the site and its surrounding catchment been specifically assessed for PFAS under a current, appropriately scoped investigation? A Phase I study completed before 2020, or one that did not explicitly address PFAS pathways, will not answer this question. A PFAS-specific desktop review, followed by targeted Phase II investigation where warranted, is now the minimum standard for defensible environmental due diligence on industrial and former-industrial land.