0201943 O'Day The proposed project will examine the mobilization of arsenic from sediments where it occurs in association with iron oxyhydroxides. The project will focus on a specific study site, North Haiwee Reservior near Olancha, California, where the input of arsenic to the sediments is controlled by engineering practices of known duration and magnitude and which has been the subject of a preliminary study by the research group. The project focuses on a specific field site because of the unique opportunities that site offers. It is anticipated that the mechanisms of iron and arsenic mobilization at Haiwee will be relevant to a variety of iron-dominated systems including aquifer sediments. Further, the information that is obtained on the timescales for arsenic release from sediments and the factors governing these timescales will increase understanding of the kinetic controls on arsenic concentrations in contacting porewaters and groundwaters.
