Speaker: Haizhou Liu, Superfund Research Program http://superfund.berkeley.edu/ and Department of Civil and Environmental Engineering http://www.ce.berkeley.edu/, University of California Berkeley http://berkeley.edu/. Research support by the Superfund Research Program of NIEHS http://www.niehs.nih.gov/research/supported/srp/ Many hazardous sites are contaminated below the surface. One method to reduce contamination is to transform contaminants to less toxic forms. Traditionally, hydrogen peroxide is used to generate a reactive compound (radical) that is needed for this to occur. Haizhou Liu shows that it is important to understand the efficiency of the production of radicals as well as their half life in the subsurface. His research shows that using hydrogen sulfate to create radicals has advantages including greater efficiency of production and longer half life in the subsurface. This would be especially valuable to treat contaminants far below the surface.