As part of a robust PFAS monitoring strategy, EA is prioritising monitoring activity and using the resulting data to identify risks, target regulatory action, and support remediation, in line with the intent of this recommendation. The PFAS Plan outlines this work which and how we will work with relevant regulators across devolved governments as appropriate, to ensure a coherent and consistent approach to PFAS monitoring, enforcement and remediation across the UK. EA’s PFAS monitoring programme is a core component of the PFAS Plan and is being used to identify risks, prioritise regulatory action, and guide remediation efforts. Monitoring data are used to identify hotspots, assess trends, and inform riskbased prioritisation of regulatory interventions, including permit reviews and compliance action. EA operates one of the most comprehensive PFAS environmental monitoring programmes in the world. The PFAS Risk Screening Programme has provided a structured mechanism for combining monitoring data with information on potential source sites and sensitive environmental receptors. This has enabled the development of a national picture of the nature and extent of potential PFAS contamination across England, alongside a prioritised ranking of facilities requiring further assessment. The overarching aim is to support the targeted allocation of regulatory resources towards those sites where intervention is most likely to effectively address contamination risks. EA applies robust, scientifically grounded approaches to interpret PFAS monitoring data. Techniques such as Generalised Additive Models are used to identify longterm trends, spatial variability and seasonal patterns, while accounting for uneven sampling and data below detection limits. Grouping PFAS by structure and chain length enables coherent interpretation across a diverse set of substances. Interpretation is undertaken carefully, recognising methodological and environmental complexity. Results are considered alongside Environmental Quality Standards (EQS) and trends are interpreted in the context of relatively short monitoring periods, evolving networks and strong spatial variability linked to both point and diffuse sources. This approach provides clear but balanced insight into environmental behaviour and risk. Monitoring shows statistically robust declines in legacy PFAS such as PFOS and PFOA in English rivers (around 30% since 2016), demonstrating that regulatory controls are delivering measurable improvements. At the same time, analysis highlights continued widespread presence, local exceedances, and differences between environmental compartments, with shortchain PFAS dominating water and longchain PFAS accumulating in biota. EA also makes its PFAS data publicly available and works with researchers and stakeholders to maximise its value, recognising that ongoing monitoring and evidence development are needed to strengthen understanding and support effective decision-making. Environmental monitoring data informs advice to local authorities on contaminated land, private water supplies, and planning applications where risks to sensitive receptors are identified. Where monitoring identifies potential PFAS issues linked to regulated activities, EA has powers to act. A transparent link between monitoring, risk management, and enforcement is essential to build confidence that the strategy delivers meaningful environmental and public health protection. Operator led monitoring plays a critical role where more detailed, site-specific information is required. EA can require companies who operate under an EA permit to undertake enhanced monitoring and investigations to better characterise PFAS sources, pathways and risks. Where operator led monitoring is required, EA heavily scrutinises the methods and data produced throughout the process. This approach supports proportionate regulation, enables targeted enforcement and remediation, and ensures that costs are borne by those responsible for pollution, in line with the polluter pays principle. EA is currently gathering data from multiple non-hazardous landfill sites to establish the scale and scope of the presence of PFAS and subsequent emissions from these landfills. The work includes: • Investigating the leachate source term and whether the existing on-site treatment technologies are capable of destroying/removing the PFAS from the effluent. • Investigating the landfill gas source term and whether landfill gas emissions present a challenge like landfill leachate. These studies will inform future regulation by introducing enhanced monitoring by landfill operators, undertaking site-specific risk assessments on leachate and potentially landfill gas emissions. Finally, engagement with the wider industry to explore alternative treatment technologies where required. The transport and emission of PFAS from wastewater treatment has been investigated in the Chemicals Investigation Programme (CIP). CIP represents a collaboration between EA and the ten wastewater companies in England and Wales.