Perchlorate: Challenges and Lessons.- The Chemistry of Perchlorate in the Environment.- Occurrence and Formation of Non-Anthropogenic Perchlorate.- Alternative Causes of Wide-Spread, Low Concentration Perchlorate Impacts to Groundwater.- Stable Isotopic Composition of Chlorine and Oxygen in Synthetic and Natural Perchlorate.- Recent Developments in Perchlorate Detection.- The Ecotoxicology of Perchlorate in the Environment.- Perchlorate Toxicity and Risk Assessment.- Using Biomonitoring to Assess Human Exposure to Perchlorate.- Recent Advances in Ion Exchange for Perchlorate Treatment, Recovery and Destruction.- Field Demonstration using Highly Selective, Regenerable Ion Exchange and Perchlorate Destruction Technologies for Water Treatment.- The Microbiology of Perchlorate Reduction and its Bioremediative Application.- The Biochemistry and Genetics of Microbial Perchlorate Reduction.- Field Demonstration of In Situ Perchlorate Bioremediation in Groundwater.- Perchlorate Removal by Modified Activated Carbon.- Titanium Catalyzed Perchlorate Reduction and Applications.- Membrane and Other Treatment Technologies — Pros and Cons.