ABSTRACT
We present here the results of a year-long geochemical study of the ground water near Fairbanks, Alaska U.S.A, with a focus on the controls on the sporadic elevated arsenic concentrations. Based on preliminary data we observe large variations in chemical concentration between the seventeen wells. However, the groundwater chemistry for any given well in this study appears to be constant and independent of the time of sampling. The groundwaters sampled in this study have had a long, though unquantifiable residence time, as shown in the relatively high specific conductance (up to 1154 µS·cm-1) and neutral pH (6.2-7.4). Seven of seventeen wells sampled have arsenic concentrations >8.3 ppb, five of these wells have As(III) as the dominant arsenic species. The elevated arsenic concentrations appear to be the result of remobilization of arsenic from secondary As-bearing phases such as iron-hydroxide.
