Demonstration/Validation of the Snap Sampler Passive Ground Water Sampling Device for Sampling Inorganic Analytes at the Former Pease Air Force Base

Abstract

Laboratory studies and a field demonstration were conducted to determine the ability of the Snap Sampler to recover representative concentrations of several types of inorganic analytes from ground water. Analytes included non-metals, transition metals, alkaline earth metals, alkali metals, and a metalloid. In the laboratory studies, concentrations of analytes in Snap Sampler samples were com-parable with concentrations of the analytes in samples collected from a standpipe (i.e., control samples). For the field demonstration, there were sampling events 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. Based upon statistical analyses, analyte concentrations were found to be equivalent to those in the low-flow samples with one exception -unfiltered iron, where concentrations were significantly higher in the Snap Sampler samples. Differences were most pronounced in samples collected from the two stainless steel wells and from wells with higher turbidity levels. 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.

Demonstration/Validation of the Snap Sampler Passive Ground Water Sampling Device

“…More detailed findings from the flowmeter testing under low-flow pumping can be found in Parker et al (2009). The measurements indicated a variety of flow patterns in the test wells.…”

“…The thickness of the overlying, unconsolidated lithological units varies across the site as the elevation of the bedrock interface is highly variable. Cross-sections of the stratigraphy of this zone can be found in Parker et al (2009) and are characteristic of the stratigraphy of the entire site. The top 20 ft of bedrock at site 32 is relatively highly fractured.…”

“…These tests were conducted under both static and low-flow pumping conditions. Additional information on this sampling technology and the field methods used in this study can be found in Parker et al (2009).…”

“…The samplers were left in the well for one week before collection. Additional details on the methods used and the data from this testing can be found in Parker et al (2009).…”

“…This testing was conducted in our laboratory and details on the sampling methods can be found in Parker et al (2009). Generally, concentrations for the blank samples indicated that leaching of constituents from the test equipment was not a concern.…”