Forever Chemicals in the Garden: What Happens When Contamination Emerges After Purchase?

Residents discover that soil in and around their gardens contains a chemical associated with decades of industrial activity. Investigations continue, official advice changes as evidence develops and homeowners are left asking what the findings could mean for their health, property values and ability to sell or remortgage.

That is the difficult position facing parts of Thornton-Cleveleys in Lancashire, where a multi-agency investigation has examined possible historic contamination involving perfluorooctanoic acid, commonly known as PFOA.

PFOA belongs to the wider family of per- and polyfluoroalkyl substances, or PFAS. These are often described as “forever chemicals” because of their environmental persistence.

The situation presents a wider conveyancing question. What happens when an environmental risk is identified years after homes were purchased, particularly where the relevant contamination may not have been recorded, investigated or understood at the time?

What has been identified in Thornton-Cleveleys?

Wyre Council launched a multi-agency investigation into possible historic contamination associated with the former ICI site at the Hillhouse Technology Enterprise Zone. The investigation considers whether PFOA used at the site between the 1950s and 2012 may have been released into the air and deposited on surrounding land.

Soil sampling was undertaken at residential properties and other locations. A March 2026 report stated that PFOA had been detected in soil samples from a majority of 71 residential properties tested. Most were said to require no further action at that stage, while seven were identified as requiring further investigation.

A separate official assessment concerned Occupation Road Allotments. Wyre Council reported that the Environment Agency had concluded that this site met the statutory criteria for classification as contaminated land because of potential risks arising from PFOA found in soil and produce.

The council’s update published on 5 March 2026 expressly cautioned that its conclusions related to the allotment site. It said that no conclusions or decisions had been reached about the contaminated land status of other land or properties forming part of the wider investigation.

That distinction must be maintained. Detection of a chemical in a soil sample, identification of a property for further assessment and formal determination as contaminated land under Part 2A of the Environmental Protection Act 1990 are not interchangeable conclusions.

Why contamination does not produce a simple yes or no answer

The word “contaminated” is often used generally to describe the presence of an unwanted substance. The statutory contaminated land regime applies a more specific test.

An investigation may need to establish:

• what substance is present;
• the concentration in which it is found;
• how the substance reached the land;
• whether there is a pathway through which exposure can occur;
• who or what could be harmed;
• whether the statutory threshold of harm or possibility of harm is met; and
• what remediation or other action is appropriate.

The significance of a result may also depend on how the land is used. An allotment holder who regularly eats produce grown in the soil may have a different exposure profile from a homeowner who does not grow food.

This explains why one site may meet the statutory criteria while investigations continue elsewhere. It also demonstrates why a property transaction cannot safely reduce a technical environmental assessment to a label such as “passed” or “failed”.

Could the contamination affect a future sale?

Even before land is formally determined as contaminated, an unresolved investigation can affect a property transaction.

A prospective buyer may want to know:

• whether the property was sampled;
• what substances were detected and at what concentrations;
• whether further testing has been recommended;
• what official advice currently applies;
• whether remediation could be required;
• who would be responsible for its cost;
• whether home-grown produce can safely be consumed;
• whether children can use the garden normally;
• whether the buyer’s proposed lender will accept the property; and
• what must be disclosed when the property is sold again.

The uncertainty may itself become a transaction risk. A buyer may delay exchange while awaiting further evidence. A valuer may recommend specialist investigation. A mortgage lender may refer the case for additional consideration or decline to proceed until the position is clarified.

This does not mean every affected property is unsellable or unmortgageable. It means that saleability and mortgageability may depend on the property-specific evidence, the lender involved and the status of the investigation at the relevant time.

Would an environmental search have revealed the risk?

A standard residential environmental search is generally a desktop report compiled from available records and datasets. It is not a physical inspection of the garden and does not ordinarily involve soil sampling.

A search may identify previous industrial activity, regulatory records or potentially contaminative land use. It may recommend further assessment. However, it cannot necessarily reveal a chemical deposit that had not been investigated, recorded or linked to the property when the search was produced.

A search result described as clear or passed should therefore not be interpreted as a guarantee that the soil has been physically tested and found free from contamination.

When a contamination issue emerges years later, the correct questions include:

• What historical land uses were recorded when the property was bought?
• What datasets were available to the search provider?
• Did the search identify the nearby industrial site?
• Did it recommend further investigation?
• Were any regulatory investigations already underway?
• What was known by the seller?
• What did the surveyor observe?
• What advice did the conveyancer give about the search and its limitations?

The later discovery of PFOA does not, by itself, prove that the original conveyancer or search provider should have discovered it. The answer depends on the information reasonably available at the time and what that information required the relevant professional to do.

What should be disclosed when an affected property is sold?

A seller should answer the property information forms and any additional enquiries honestly and accurately. Where the property has been sampled or included in a public investigation, relevant correspondence, test results and official updates should be supplied to the seller’s conveyancer.

Potentially relevant material may include:

• letters from the council, Environment Agency or another public body;
• soil, water or produce sampling results;
• environmental consultant reports;
• official health or food safety advice;
• records of any remediation or precautionary work;
• insurance documents;
• correspondence concerning liability or compensation; and
• information about continuing monitoring or investigation.

The seller should not attempt to interpret incomplete scientific results as proof that the land is safe. Equally, the seller should not describe the property as formally designated contaminated land unless that is the actual legal position.

The safest approach is accurate disclosure of the documents and status of the investigation, supported by appropriate environmental and legal advice.

The buyer needs more than a bundle of technical documents

Supplying a report is not necessarily the same as explaining its significance.

The buyer may need clear advice addressing:

• what has and has not been established;
• whether further results are awaited;
• the limitations of the investigation completed so far;
• the official advice applying to use of the garden;
• potential remediation and monitoring obligations;
• the mortgage lender’s position;
• the possible effect on value and future saleability; and
• what uncertainty the buyer will assume on completion.

If these questions cannot be answered before exchange, the buyer must understand that they are proceeding while a material environmental investigation remains unresolved.

A mortgage offer does not remove that uncertainty. The current lender’s willingness to lend is relevant, but it does not establish how another lender, buyer or valuer will assess the property several years later.

What did the mortgage lender require when the property was bought?

If contamination later affects a sale or remortgage, it may be necessary to examine the original mortgage lender’s requirements.

The current UK Finance Mortgage Lenders’ Handbook cannot establish what the lender required on an earlier transaction date. Lenders amend their instructions concerning environmental searches, contaminated land reports, specialist evidence, valuation concerns and matters that must be reported before completion.

The Lexsure Lender Archive contaminated land records allow the user to select the original lender and transaction date. This may help establish the lender wording recorded at the relevant time.

The historical record may assist in determining:

• whether the environmental search result had to be reported;
• whether further investigation was required;
• whether the lender relied upon the valuer;
• whether an adverse environmental matter required lender approval;
• whether insurance was an acceptable response; and
• how the wider mortgage market treated contaminated land at that date.

The archive cannot establish whether the contamination was discoverable or whether anybody was negligent. It provides evidence of the recorded lender instructions. Those instructions must be considered alongside the mortgage offer, valuation, searches, correspondence, title documentation and advice given to the buyer.

What should an owner check from the original purchase?

A homeowner whose property becomes involved in a later contamination investigation should try to recover the original purchase file. Relevant documents may include:

• the environmental search and search provider’s terms;
• the local authority search;
• the seller’s property information form;
• pre-contract enquiries and replies;
• the mortgage valuation and any private survey;
• planning documents and information about previous land use;
• the conveyancer’s Report on Title;
• the mortgage offer and special conditions;
• any contaminated land insurance policy; and
• the mortgage lender requirements applying at the time.

The investigation should distinguish between information that existed when the property was bought and evidence that emerged only afterwards. Hindsight should not be used to assume that a risk was previously known. Equally, a warning contained in the original material should not be overlooked merely because no formal contaminated land determination had then been made.

Could contaminated land indemnity insurance resolve the problem?

Indemnity insurance may be proposed in some contaminated land transactions, potentially with the seller meeting the premium. Its suitability will depend on the identified risk, the policy wording and the buyer’s mortgage lender.

For an example of how such an arrangement may be explained to a buyer, see the Lexsure Report on Title paragraph concerning a contaminated land indemnity policy where the seller bears the cost.

An insurance policy is not a scientific conclusion that the land is safe. It does not remove PFOA from soil, provide health advice or automatically fund every form of investigation and remediation.

The policy must be checked carefully to establish:

• the precise insured risk;
• who is protected;
• the duration and limit of cover;
• whether future owners and lenders are included;
• what investigation and remediation costs are covered;
• what exclusions apply;
• whether existing knowledge or official investigation affects cover; and
• whether contact with public authorities or third parties is restricted.

Where contamination is already known and subject to an active public investigation, ordinary contaminated land indemnity cover may be unavailable or materially restricted. Insurance should not be assumed to provide a solution until an insurer has assessed the particular facts.

Why the Thornton-Cleveleys story matters beyond one community

The investigation illustrates a problem that may become increasingly important for residential conveyancing. Historic industrial emissions can be investigated decades after surrounding homes were built and sold. Scientific understanding, regulatory attention and testing capabilities also develop over time.

A buyer may therefore acquire a property without any known formal contamination issue, only for new evidence to emerge years later.

That possibility does not make ordinary conveyancing protection meaningless. It makes it essential to understand the limits of each part of the process:

• a desktop search is not a soil test;
• a mortgage valuation is not an environmental assessment;
• a lender’s acceptance does not guarantee future marketability;
• insurance does not physically remediate contamination; and
• providing a report does not replace clear advice about its significance.

When a previously unknown environmental problem emerges, the original purchase file and historical lender requirements may help establish what was reasonably knowable at the time. They may also show whether an available warning was properly investigated and explained.

This article is for general information only and does not provide legal, health, scientific or environmental advice. The investigation discussed is continuing. Findings relating to one site or property should not be applied to another. Anyone affected should obtain current guidance from the responsible public authorities and advice from appropriately qualified environmental, legal, valuation and medical professionals.