Use of Passive Diffusion Samplers for Monitoring Volatile Organic Compounds in Ground Water

Abstract

Passive diffusion samplers have been tested at a number of sites where volatile organic compounds (VOC's) are the principal contaminants in ground water. Test results generally show good agreement between concentrations of VOC's in samples collected with diffusion samplers and concentrations in samples collected by purging the water from a well. Diffusion samplers offer several advantages over conventional and low-flow groundwater sampling procedures: • Elimination of the need to purge a well before collecting a sample and to dispose of contaminated water. • Elimination of cross-contamination of samples associated with sampling with non-dedicated pumps or sample delivery tubes. • Reduction in sampling time by as much as 80 percent of that required for "purge type" sampling methods. • An increase in the frequency and spatial coverage of monitoring at a site because of the associated savings in time and money. The successful use of diffusion samplers depends on the following three primary factors: (1) understanding site conditions and contaminants of interest (defining sample objectives), (2) validating of results of diffusion samplers against more widely acknowledged sampling methods, and (3) applying diffusion samplers in the field.

Borehole‐scale testing of matrix diffusion for contaminated‐rock aquifers

“…Vertical chemical profiling of CVOCs and other volatile organics of groundwater in wells BBC3 and BBC4 was performed for this study using passive diffusion bag (PDB) samplers (Harte, 2002;Harte, Brayton, & Ives, 2000). Multiple PDB samplers were deployed at different depths in the open borehole based on the interpretation of likely flow zones from the previously collected borehole geophysical log results (Bothner et al, 2010) Reston, Virginia, using gas chromatography procedures (Busenberg, Plummer, Bartholomay, & Wayland, 1998).…”

Application of a New Vertical Profiling Tool (ESASS) for Sampling Groundwater Quality During Hollow‐Stem Auger Drilling

“…EM conductivity was converted to equivalent pore water conductivity by utilizing an Archie Law relation (Archie 1942). Wells were sampled for VOCs following low-flow protocol (a low-flow rate to minimize mixing of the water column in the well) and using pdb sampling techniques (Harte et al 2000). PCE concentrations from the ESASS profile were compared to PCE concentrations from wells installed within the same ESASS profile hole and other nearby locations.…”