New opportunities for groundwater hydrochemistry and degradation investigations provided by the Snap SamplerRTM

An estimated 1.9 million litres of trichloroethylene (TCE) was released into the subsurface at a fractured sandstone field site in Southern California in the mid 1900's. Degradation products of TCE have been found during previous hydrochemical investigations using conventional aggressive sampling methods in open rock monitoring wells on site. The need to better quantify the amount of volatile degradation products present in the groundwater led to the use of advanced sampling methods in fourteen wells. The Snap Sample RTM is a passive downhole sampling device where point samples are sealed in the well, brought to the surface, and then submitted to the laboratory without exposure to the air. Variable concentrations of parameters seen with depth were influenced by vertical flow in borehole. Snap SampleRTM results showed higher concentrations and further detection of dissolved gases when compared to conventional sampling methods by the use of this efficient and versatile advanced sampling method.