Evaluation of the Hydrogeology and Groundwater Chemistry Associated with Landfills at LLNL'S Site 300

摘要

Potential groundwater contamination from eight solid waste landfills within LLNL's Site 300 has been assessed. Investigations included extensive geological, hydrological, geophysical, and geochemical studies directed toward an evaluation of hydrogeology and groundwater chemistry in the vicinity of the landfill locations. A state-of-the-art groundwater sampling system was installed, which allows for collection of samples and piezometric measurements from discrete isolated sampling zones. Multiple completions were made in eight of the 17 boreholes completed for groundwater sampling, to permit analysis of deeper aquifers as well as the uppermost water-bearing zone (the water table). To prevent cross-contamination between aquifers during drilling, an aquifer isolation technique was developed. Special precautions were taken in drilling and well completion procedures to minimize the introduction of contaminants. Three separate sets of hydrological measurements and chemical analyses were made to identify the direction of groundwater flow from the landfills and to establish whether any contaminants had been introduced into the groundwater. No groundwater contamination levels were found that would threaten human health or the environment. 80 references. (ERA citation 09:001248)