The report discusses groundwater monitoring and cleanup efforts at the Hanford Site in Washington for fiscal year 2000. The main contaminants found were tritium, iodine-129, nitrate, carbon tetrachloride, and hexavalent chromium. Strontium-90, technetium-99, and uranium were also detected in specific areas. The researchers focused on identifying uncertainties in the current conceptual model and calibrating the site-wide groundwater model. They also conducted soil gas monitoring to locate tritium in the vadose zone and groundwater. The findings support ongoing remediation efforts and the development of predictive models for cumulative site-wide contaminant effects.