What is PFAS?
PFAS (per- and polyfluoroalkyl substances) are a group of man‑made chemicals used in a wide range of industrial processes and consumer products. They are sometimes known as “forever chemicals”. This includes chemicals that were historically used in fire‑fighting foams, including at airfields and military sites.
How does this relate to Heyford Park?
As part of the Environment Agency’s national PFAS research and monitoring programme, the Environment Agency carries out targeted sampling of groundwater and surface water across England to build a national understanding of PFAS in the environment. One of these locations is around 5 km from Upper Heyford. The Environment Agency and local organisations have identified PFAS in local watercourses near Heyford Park. Sampling has found varying concentrations, which may reflect factors such as distance from potential sources and dilution within the water environment.
The former RAF Upper Heyford airbase is known to have used fire-fighting foams in the past.
Is there a risk to health?
At present, there is no evidence to suggest an immediate risk to the health of residents.
Following recent discussions involving the council, the Environment Agency and other partners, Thames Water has advised that:
The drinking water supply serving the Heyford area complies with Drinking Water Inspectorate (DWI) PFAS guidelines. Routine monitoring at the relevant Water Treatment Works (WTWs) has not identified any PFAS concentrations of significant concern, according to the DWI guidelines (no tier 3 results). Based on current evidence, the risk of contamination to drinking water supplies from the nearby airfield is considered to be low. This is because relevant water abstraction points that supply the area are either located a considerable distance from the airfield or positioned upstream of it which means it's unlikely that contamination can interact with the abstraction source.
Who is responsible for investigating water pollution and drinking water safety?
- The Environment Agency may take samples from rivers and streams when responding to a pollution incident, where appropriate. Where development is proposed, even where the Environment Agency is not a statutory consultee, it works with local planning authorities to help ensure that land and any impacted groundwater are cleaned up to a standard which is suitable for the site's proposed use, both now and in the future. More information on the Environment Agency's role can be found here
- Drinking water standards are set by the Drinking Water Inspectorate (DWI). Further information is available here
- Drinking water at Upper Heyford is supplied by Thames Water via the mains network, not from private water supplies
Have measures to address contaminated land already been taken when granting planning applications at Heyford Park?
Yes.
Where development has already taken place at Heyford Park, land contamination was assessed and remediated where necessary, in line with the legislation and guidance that applied at the time those developments were approved.
What about new or future development at Heyford Park?
For any new planning applications, the council will:
- Assess each application on its own merits
- Require appropriate land contamination investigations, where relevant
- Ensure that testing, remediation and verification are carried out in line with current national guidance
- Take a precautionary and evidence‑led approach, particularly for sensitive uses such as housing
If additional investigation or mitigation is required because of PFAS or other contaminants, this will be secured through the planning process.
Where development is proposed on land affected by contamination or land stability issues, responsibility for securing a safe development rests with the developer and/or landowner.
What is the national position on PFAS?
PFAS are recognised as an emerging national issue.
The Government has published a policy paper setting out its approach to managing PFAS and is working towards further national guidance on legacy contamination.
Read further information online
What is the council doing?
Cherwell District Council will continue to:
- Work with expert regulators such as the Environment Agency
- Follow national planning and environmental guidance
- Take a proportionate, precautionary and evidence‑led approach
- Ensure land is safe for its intended use through the planning process
If you have a specific concern about this issue that hasn’t been answered above, please use our dedicated email address: pfas@cherwell-dc.gov.uk
PFAS Roundtable at Heyford Park
On 24 August 2026, representatives from Cherwell District Council, the Environment Agency, UK Health Security Agency (UKHSA), Oxfordshire County Council, Thames Water, Dorchester Living and other partner organisations met with Callum Miller MP to discuss PFAS contamination associated with Heyford Park.
The discussion focused on how organisations can work together to improve public understanding of the issue, coordinate future investigations and ensure residents have access to clear, trusted and consistent information.
Agreed priorities
Participants identified five key areas where progress is needed:
- Improving understanding of the extent of contamination.
- Developing a clearer picture of impacts on soil, water and the wider environment.
- Improving understanding of potential human exposure pathways and health considerations.
- Providing reassurance through evidence-based investigation and assessment.
- Ensuring residents can access clear and understandable information.
Key outcomes
Commitment to partnership working
Participants recognised that PFAS is a complex emerging issue requiring input from a range of organisations, each with different responsibilities and areas of expertise.
There was broad agreement that continued collaboration between local authorities, environmental regulators, public health organisations, water companies, developers and other stakeholders will be essential as work progresses.
Environmental monitoring
The Environment Agency agreed to review opportunities for additional environmental monitoring and sampling and provide an update to partners.
Participants also discussed the importance of improving public understanding of where environmental investigations have taken place and what information is currently available.
Improved public information
Participants agreed that this webpage should remain the primary source of public information.
Partners will continue to work together to improve the accessibility of information relating to:
- Agency roles and responsibilities.
- Environmental monitoring activities.
- Available evidence and technical information.
- Frequently raised community concerns and questions.
Developing future workstreams
Participants discussed a number of areas that would benefit from further collaborative work, including environmental monitoring, public health and exposure pathways, and public communications.
It was recognised that future arrangements will require appropriate governance structures, clearly defined responsibilities and participation from relevant partner organisations. Several organisations indicated their willingness to contribute specialist expertise as these arrangements develop.
Future specialist input
Participants agreed that future discussions would benefit from input from additional organisations, including the Food Standards Agency (FSA) and the Drinking Water Inspectorate (DWI), to help address questions relating to food production, drinking water and potential exposure pathways.
Next steps
Immediate actions arising from the discussion include:
- Reviewing opportunities for additional environmental monitoring.
- Improving public information regarding organisational responsibilities.
- Exploring ways to present environmental data and findings more clearly.
- Considering appropriate arrangements for future partnership working.
- Continuing collaboration to ensure residents receive clear, accurate and consistent information.
Roles and responsibilities
Environment Agency
Specifically regarding PFAS chemicals, the Environment Agency’s role includes:
- ensuring compliance with legislative requirements (where the Environment Agency is the competent authority)
- monitoring and advising on the state of the environment
- providing technical advice to Government to support the development of environmental policy
- promoting scientific research in support of these roles
- collaborating with others to generate evidence and sharing our evidence with partners who play a role in managing risks from chemicals
Cherwell District Council
Cherwell District Council is responsible for:
- Determining planning applications.
- Ensuring that appropriate land contamination assessments are carried out as part of the planning process where required.
- Securing investigation, remediation and verification works through planning conditions where necessary.
- Providing information to residents and coordinating communications with relevant organisations.
- Environmental Health functions within the district.
UK Health Security Agency (UKHSA)
UKHSA is the government body responsible for providing advice on public health matters.
Its role includes:
- Assessing potential impacts on human health.
- Reviewing scientific evidence relating to PFAS.
- Providing public health advice to local authorities and other organisations where appropriate.
Drinking Water Inspectorate (DWI)
The Drinking Water Inspectorate regulates drinking water quality in England.
Its role includes:
- Setting and enforcing drinking water standards.
- Overseeing the quality of public water supplies.
- Ensuring water companies meet regulatory requirements.
Developer/landowner
Developers and/or landowners, in this case, Dorchester Living carry out investigations in support of existing and proposed development at Heyford Park.
Its role includes:
- Carrying out site investigations.
- Assessing potential contamination risks associated with development proposals.
- Preparing technical information to support planning applications.
- Developing any necessary remediation strategies required through the planning process.
Water Companies
Water companies, in this case, Thames Water is responsible for providing and monitoring public drinking water supplies in the area. The company undertakes routine monitoring of drinking water and is required to comply with standards set by the Drinking Water Inspectorate.