Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for VOCs and Explosives

Parker, Louise V.; Mulherin, Nathan D.

doi:10.21236/ada471723

Cited by 8 publications

(15 citation statements)

References 17 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As such, they are well suited for determining depth‐discrete concentrations within a well. Several other grab‐sample devices have been developed and tested extensively, including in situ sealed samplers (i.e., Snap Samplers) (ITRC 2007; Parker and Mulherin 2007; Britt et al 2010). Extensive technical and regulatory guidance has been published, including the results of comparative validation studies.…”

Section: Introductionmentioning

confidence: 99%

Field Investigation of Vapor‐Phase‐Based Groundwater Monitoring

Adamson¹,

McHugh²,

Rysz³

et al. 2011

Groundwater Monitoring Rem

View full text Add to dashboard Cite

The use of in‐field analysis of vapor‐phase samples to provide real‐time volatile organic compound (VOC) concentrations in groundwater has the potential to streamline monitoring by simplifying the sample collection and analysis process. A field validation program was completed to (1) evaluate methods for collection of vapor samples from monitoring wells and (2) evaluate the accuracy and precision of field‐portable instruments for the analysis of vapor‐phase samples. The field program evaluated three vapor‐phase sample collection methods: (1) headspace samples from two locations within the well, (2) passive vapor diffusion (PVD) samplers placed at the screened interval of the well, and (3) field vapor headspace analysis of groundwater samples. Two types of instruments were tested: a field‐portable gas chromatograph (GC) and a photoionization detector (PID). Field GC analysis of PVD samples showed no bias and good correlation to laboratory analysis of groundwater collected by low‐flow sampling (slope = 0.96, R2 = 0.85) and laboratory analysis of passive water diffusion bag samples from the well screen (slope = 1.03; R2 = 0.96). Field GC analysis of well headspace samples, either from the upper portion of the well or at the water‐vapor interface, resulted in higher variability and much poorer correlation (consistently biased low) relative to laboratory analysis of groundwater samples collected by low‐flow sample or passive diffusion bags (PDBs) (slope = 0.69 to 0.76; R2 = 0.60 to 0.64). These results indicate that field analysis of vapor‐phase samples can be used to obtain accurate measurements of VOC concentrations in groundwater. However, vapor samples collected from the well headspace were not in equilibrium with water collected from the well screen. Instead, PVD samplers placed in the screened interval represent the most promising approach for field‐based measurement of groundwater concentrations using vapor monitoring techniques and will be the focus of further field testing.

show abstract

Section: Introductionmentioning

confidence: 99%

Field Investigation of Vapor‐Phase‐Based Groundwater Monitoring

Adamson¹,

McHugh²,

Rysz³

et al. 2011

Groundwater Monitoring Rem

View full text Add to dashboard Cite

show abstract

“…Our laboratory has conducted both laboratory and field studies that have evaluated the ability of the Snap Sampler to recover representative concentrations of VOCs and explosives in ground water (Parker and Mulherin, 2007). The laboratory studies were conducted in a large (244 cm or 8 ft tall, 20 cm or 8-inch diameter) polyvinyl chloride (PVC) standpipe that contained known concentrations of either a suite of VOCs or explosives.…”

Section: Technology Developmentmentioning

confidence: 99%

“…In our field studies (Parker and Mulherin, 2007), we evaluated the ability of this sampler to recover equivalent concentrations of VOCs and explosive compounds when compared with the USEPA's low-flow purging and sampling method (USEPA Region 1, 1996 The results of the statistical analyses of the data from all the sites indicated that there were no statistically significant differences between the concentrations of VOCs and explosives in the samples taken with the Snap Samplers versus the low-flow samples.…”

Section: Technology Developmentmentioning

confidence: 99%

“…In contrast, there are no losses of these analytes in samples collected with the Snap Sampler when it has been equilibrated before collection (Parker and Mulherin, 2007). However, there is a primary distinction between lowflow purging and sampling and using the Snap Sampler-the Snap Sampler can be used to collect a sample at a discrete depth in the well, whereas the low-flowing sampling collects a sample that is a flow-weighted average over the screened interval.…”

Section: Advantages and Limitations Of The Technologymentioning

confidence: 99%

“…Two weeks is more than enough time for the materials in the RGC samplers and Snap Samplers to equilibrate with the analytes in the well water (and thus prevent losses from sorption) and also gives the well time to recover from any disturbance caused by placing the samplers in most wells, except for wells in fine-grained materials, fractured rock, shale, etc. (Vroblesky, 2001;Halevy et al, 1967 (Parker and Mulherin, 2007) and within 2 days for inorganic analytes (Parker et al, 2008(Parker et al, , 2009. While low-flow sampling equipment (i.e., pump and tubing) and the Snap Sampler can be left in the well for an extended period (e.g., months), it may not be feasible to leave RGC samplers in the well for extended equilibration times because the membrane can undergo biodegradation.…”

Section: Deployment Of Sampling Equipmentmentioning

confidence: 99%

See 2 more Smart Citations

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

Parker¹

2011

View full text Add to dashboard Cite

A Downhole Passive Sampling System To Avoid Bias and Error from Groundwater Sample Handling

Britt

Parker

Cherry

2010

Environ. Sci. Technol.

View full text Add to dashboard Cite

A new downhole groundwater sampler reduces bias and error due to sample handling and exposure while introducing minimal disturbance to natural flow conditions in the formation and well. This "In Situ Sealed", "ISS", or "Snap" sampling device includes removable/lab-ready sample bottles, a sampler device to hold double end-opening sample bottles in an open position, and a line for lowering the sampler system and triggering closure of the bottles downhole. Before deployment, each bottle is set open at both ends to allow flow-through during installation and equilibration downhole. Bottles are triggered to close downhole without well purging; the method is therefore "passive" or "nonpurge". The sample is retrieved in a sealed condition and remains unexposed until analysis. Data from six field studies comparing ISS sampling with traditional methods indicate ISS samples typically yield higher volatile organic compound (VOC) concentrations; in one case, significant chemical-specific differentials between sampling methods were discernible. For arsenic, filtered and unfiltered purge results were negatively and positively biased, respectively, compared to ISS results. Inorganic constituents showed parity with traditional methods. Overall, the ISS is versatile, avoids low VOC recovery bias, and enhances reproducibility while avoiding sampling complexity and purge water disposal.

show abstract

Evaluation of the Snap Sampler for Sampling Ground Water Monitoring Wells for VOCs and Explosives

Cited by 8 publications

References 17 publications

Field Investigation of Vapor‐Phase‐Based Groundwater Monitoring

Field Investigation of Vapor‐Phase‐Based Groundwater Monitoring

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

A Downhole Passive Sampling System To Avoid Bias and Error from Groundwater Sample Handling

Contact Info

Product

Resources

About