1. Introduction to Groundwater Remediation of Metals, Radionuclides, and Nutrients with Permeable Reactive Barriers 2. Design and Performance of Limestone Drains to Increase pH and Remove Metals from Acidic Mine Drainage 3. Preliminary Investigation into the Suitability of Permeable Reactive Barriers for the Treatment of Acid Sulfate Soils Discharge 4. Permeable Reactive Barrier / GeoSiphon Treatment for Metals-Contaminated Groundwater 5. Deep Aquifer Remediation Tools: Theory, Design, and Performance Modeling 6. Creation of a Subsurface Permeable Reactive Barrier Using in Situ Redox Manipulation 7. Development and Performance of and Iron Oxide / Phosphate Reactive Barrier for the Remediation of Uranium-Contaminated Groundwater 8. Treatability Study of Reactive Materials to Remediate Groundwater Contaminated with Radionuclides, Metals, and Nitrates in a Four-Component Permeable Reactive Barrier 9. Evaluation of Apatite Materials for Use in Permeable Reactive Barriers for the Remediation of Uranium-Contaminated Groundwater 10. Sulfate-Reducing Bacteria in the Zero Valent Iron Permeable Reactive Barrier at Fry Canyon, Utah 11. Biogeochemical, Mineralogical, and Hydrological Characteristics of an iron Reactive Barrier Used for Treatment of Uranium and Nitrate 12. Analysis of Uranium-Contaminated Zero Valent Iron Media Sampled from Permeable Reactive Barriers Installed at U.S. Department of Energy Sites in Oak Ridge, Tennessee, and Durango, Colorado 13. Design and Performance of Permeable Reactive Barrier for Containment of Uranium, Arsenic, Selenium, Vanadium, Molybdenum, and Nitrate at Monticello, Utah 14. Field Demonstration of Three Permeable Reactive Barriers to Control Uranium Contamination in Groundwater, Fry Canyon, Utah 15. Collection Drain and Permeable Reactive Barrier for Treating Uranium and Metals from Mill Tailings Near Durango, Colorado 16. In Situ Reduction of Chromium-Contaminated Groundwater, Soils, and Sediments by Sodium Dithionite 17. Sulfate Reduction Permeable Reactive Barriers to Treat Acidity, Cadmium, Copper, Nickel and Zinc: Two Case Studies