This report presents the results of groundwater and vadose zone monitoring and remediation for fiscal year 1999 on the US. Department of Energy's Hanford Site, Washington. Water-level monitoring was performed to evaluate groundwater flow directions, to track changes in water levels, and to relate such changes to evolving disposal practices. Measurements for site-wide maps were conducted in June in past years and are now measured in March to reflect conditions that are closer to average. Water levels over most of the Hanford Site continued to decline between June 1998 and March 1999. The most widespread radiological contaminant plumes in groundwater were tritium and iodine-129. Concentrations of carbon-14, strontium-90, technetium-99, and uranium also exceeded drinking water standards in smaller plumes. Cesium-137 and plutonium exceeded standards only near the 216-B-5 injection well. Derived concentration guide levels specified in US Department of Energy Order 5400.5 were exceeded for plutonium, strontium-90, tritium, and uranium in small plumes or single wells. Nitrate and carbon tetrachloride are the most extensive chemical contaminants. Chloroform, chromium, cis-1,2dichloroethylene, cyanide, fluoride, and trichloroethylene also were present in smaller areas at levels above their maximum contaminant levels. Metals such as aluminum, cadmium, iron, manganese, and nickel exceeded their maximum contaminant levels …

The U.S. Department of Energy (DOE) Office of Legacy Management conducted annual sampling at the Rulison, Colorado, Site for the Long-Term Hydrologic Monitoring Program (LTHMP) on May 18, 2011. The samples were shipped to the U.S. Environmental Protection Agency (EPA) Radiation and Indoor Environments National Laboratory in Las Vegas, Nevada, for analysis. All requested analyses were successfully completed, with the exception of the determination of tritium concentration by the enrichment method. The laboratory no longer provides that service. Samples were analyzed for gamma-emitting radionuclides by high-resolution gamma spectrometry and for tritium using the conventional method. Starting in 2012, DOE will retain a different laboratory that provides the enriched tritium analysis service.