A number of iron- and aluminum-based adsorbents have been developed recently to overcome the shortcomings of traditional activated alumina (AA). The American Water Works Association Research Foundation (AWWARF) is sponsoring an ongoing project to demonstrate emerging technologies for arsenic removal including, but not limited to, adsorption. This is the first large-scale, head-to-head comparison of a wide range of promising arsenic removal technologies operating year round at the same sites. At the sites where adsorption technology is being demonstrated, the emerging adsorbents being evaluated include granular ferric hydroxide, iron-modified AA and high porosity AA. This paper presents the testing results collected to date at the City of Scottsdale and the Tucson Water test sites. The preliminary results from the testing site at Southern California will be included in the conference presentation. Includes tables, figures.