PFAS LITIGATION: EXPERT WITNESS AND DAMAGE ANALYSIS
CD: How significant is expert testimony in per- and polyfluoroalkyl substances (PFAS)-related litigation?
Williams: Expert testimony can be absolutely crucial in per- and polyfluoroalkyl (PFAS) cases- where disputes can hinge on complex scientific and technical details. Legal outcomes are heavily dependent on the right expertise, technical insight and strategic clarity. PFAS litigation typically requires multidisciplinary expert teams fluent across hydrogeology, exposure modelling, toxicology and epidemiology. An expert’s role goes beyond knowledge; they need to communicate effectively and persuasively to audiences without scientific or specialist backgrounds. This is never more true than in PFAS litigation, which requires an understanding of the sources, chemistry, fate and transport properties, and health effects in a way that is accurate and accessible.
Lee: Experts play a vital role in translating complex PFAS science into defensible arguments that stand up in court. PFAS are a large class of synthetic chemicals widely used because of their durability and surfactant properties. These same attributes also make them persistent in the environment, especially long-chain perfluoroalkyl acids (PFAAs). Most cases in the US, to date, have focused on drinking water contamination. PFAS can be highly mobile in groundwater and surface waters and have the potential to form extensive plumes. Expert analysis is indispensable in providing clarity on contamination source, migration pattern and risk exposure to support legal cases.
Jan-Mar 2026 issue
HKA