Geraint Williams



Geraint is an Associate at ALS’s laboratory in North Wales, acting as technical lead. He has over 23 years’ experience having been involved in a wide range of UK projects including the investigation and assessment of sites under planning and Part 2A. He was a technical expert in the United Nation’s environmental assessments in Nigeria and has been involved in similar projects in Cote d’Ivoire, Iraq, Afghanistan and many other countries throughout the world.
Geraint has a key interest in promoting best practice and is a member of the Contaminated Land Working Group of the Association of Geotechnical and Geoenvironmental Specialists (AGS). He wrote AGS’s guidance on sampling PFAS.
He previously served on the Executive Committee of the Society of Brownfield Risk Assessment (SoBRA) and was a member of the Technical Panel and Vapour Intrusion subgroups. In addition, Geraint serves on EH/4 - British Standard’s technical committee on soil quality and is currently on the drafting panel of two international standards.

Short description about presentation:

Per- and polyfluoroalkyl substances PFAS are present as contaminants of concern on many sites and are extremely persistent, highly mobile and can bioaccumulate. They are increasingly considered a risk to human health and the environment. This webinar will focus on the analytical options available. rnrnPFAS present many challenges for laboratories. They are ubiquitous in the environment but detection limit requirements are very low. Polyfluorinated precursors can transform following release. The number of PFAS determined by conventional analyses are limited as analytical standards are not available for these compounds.rnrnThe presentation will review common analysis approaches used, as well as providing details of more advanced techniques including Total Oxidisable Precursor TOP Assay and Total Organic Fluorine TOF analysis. The webinar will also provide guidance on sampling, how to overcome the potential difficulties of cross-contamination at Environmental Quality Standards EQS limits and include details of QAQC requirements.