Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for Inorganic Analytes

Abstract Laboratory studies and a field demonstration were conducted to determine the ability of the Snap Sampler to recover representative concentrations of inorganic analytes, including metals, from ground water. For the laboratory studies, concentrations of analytes in Snap Sampler samples were compared with concentrations of the analytes in samples collected from a standpipe i.e., control samples. These studies clearly demonstrated that Snap Sampler concentrations were comparable to control sample concentrations. For the field demonstration, 10 sampling events were conducted at the former Pease Air Force Base. Samples taken using a Snap Sampler were compared with samples collected using conventional low-flow purging and sampling and a regenerated cellulose passive diffusion sampler. Analytes included calcium, iron, magnesium, manganese, potassium, sodium, and arsenic. With one exception, Snap Sampler concentrations were equivalent to those in low-flow samples. Concentrations of unfiltered iron were higher in the Snap Sampler, especially in the two stainless steel wells, and reflected turbidity levels in the wells at the time of sampling. Elevated turbidities may have resulted from installing additional sampling equipment including the baffle, pump, samplers, and bottom weight in the well before sampling. We will examine this issue further at our next test site.