Metal contamination from mining and processing activities has resulted in an increasing threat to potable water supplies in the United States. Development of effective remediation techniques is critical for protecting drinking water supplies and for mitigating existing contamination problems. Permeable reactive barriers (PRB) provide a means for passive remediation of ground water (GW) for both organic and inorganic contaminants., The long-term (9 years) performance of an amorphous ferric oxyhydroxide (AFO) coated gravel PRB has been tested for remediating U contaminated GW at the Fry Canyon demonstration site in southeastern Utah, USA, the site of an abandoned uranium ore upgrader operation. Evaluating the reaction processes resulting in U sequestration by the AFO PRB, such as determining surface complex species, is critical to development and application of meaningful reaction terms in solute transport models for U at the site and other sites. In this study, X-ray Absorption Spectroscopy was used to investigate the U surface speciation in the AFO material recovered PRB after 9 years of reaction.