Geochemical parameters and major ion concentrations of sediments from two high arsenic boreholes and one control borehole.

I: brown, II: green; III: dark grey, IV: black □ clay, ○ silty clay, ◇ medium sand, △ fine sand ND: not determined Geochemical parameters and major ion concentrations of sediments from two high arsenic boreholes and one control borehole.