Arsenic concentrations in wells in crystalline rock aquifers

Distribution of percentages of water samples with concentrations of arsenic greater than 10 micrograms per liter collected from public-supply and domestic wells in New England crystalline rock aquifers, by categories of well depth and casing length, 1995–2007. This figure demonstrates that arsenic concentrations in water samples collected from bedrock aquifers are likely related to characteristics of the sampled wells, which in turn might be related to income (people with more wealth can generally afford deeper wells).