Project Summary (2000-2005)

The goal of this project is to characterize the sources, transport and fate of arsenic in groundwater systems in New Hampshire, which are known to contain high levels of arsenic. Researchers are studying each of the four geographic regions within New Hampshire where high arsenic levels have been identified. This includes regions where arsenic may be derived from either geologic or human-derived sources. Each of the four clusters is being investigated with respect to the hydrology and geochemistry of the groundwater systems. Basic hydrologic techniques are being used to map the regional groundwater flow patterns. Electron microprobe x-ray mapping is determining arsenic carrier phases in rocks and soils. Column experiments are measuring the chemical conditions under which arsenic is solubilized from the bedrock and soils. Species-specific chemical analyses of waters is detailing the redox conditions of the groundwater system and the chemical mechanisms responsible for arsenic mobility. And finally, the retardation properties of the bedrock and soils are being measured in column experiments. Results from this work will further general knowledge of the sources and chemistry of arsenic in the environment. This information will aid decision-making with respect to the management and remediation of arsenic-contaminated crystalline bedrock regions in New England and elsewhere.