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May 9, 2019

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Haley Schneider Coauthors Paper on Interstitial Velocity for the Journal Groundwater

Haley Schneider, Ph.D. (California) coauthored a paper entitled "Estimation of Interstitial Velocity Using a Direct Drive High-Resolution Passive Profiler" published in the journal Groundwater on February 27, 2019.

Haley is a Senior Staff Engineer based in California focused on the development of an innovative passive groundwater sampling technology in conjunction with the evaluation of existing profiling tools for the delineation of microbial communities, biogeochemical conditions, chlorinated volatile organic compounds (cVOC) concentrations, and groundwater velocity in shallow aquifers. She also has experience with SigmaPlot, Matlab, and ArcGIS softwares.

Haley's coauthors were Andrew Jackson, Ken Rainwater, Danny Reible, Stephen Morse, Paul Hatzinger and Uriel Garza-Rubalcava.     

Groundwater is the leading international journal focused exclusively on groundwater. Since 1963, Groundwater has published a mix of papers on topics related to groundwater including groundwater flow and well hydraulics, hydrogeochemistry and contaminant hydrogeology, application of geophysics, groundwater management and policy, and history of groundwater hydrology. 


The fate and transport of groundwater contaminants depends partially on groundwater velocity, which can vary appreciably in highly stratified aquifers. A high-resolution passive profiler (HRPP) was developed to evaluate groundwater velocity, contaminant concentrations, and microbial community structure at ∼20 cm vertical depth resolution in shallow heterogeneous aquifers. The objective of this study was to use mass transfer of bromide (Br−), a conservative tracer released from cells in the HRPP, to estimate interstitial velocity. Laboratory experiments were conducted to empirically relate velocity and the mass transfer coefficient of Br− based on the relative loss of Br− from HRPP cells. Laboratory-scale HRPPs were deployed in flow boxes containing saturated soils with differing porosities, and the mass transfer coefficient of Br− was measured at multiple interstitial velocities (0 to 100 cm/day). A two-dimensional (2D) quasi-steady-state model was used to relate velocity to mass transfer of Br− for a range of soil porosities (0.2–0.5). The laboratory data indicate that the mass transfer coefficient of Br−, which was directly - but non-linearly - related to velocity, can be determined with a single 3-week deployment of the HRPP. The mass transfer coefficient was relatively unaffected by sampler orientation, length of deployment time, or porosity. The model closely simulated the experimental results. The data suggest that the HRPP will be applicable for estimating groundwater velocity ranging from 1 to 100 cm/day in the field at a minimum depth resolution of 10 cm, depending on sampler design.

More Information

Learn about the article: https://doi.org/10.1111/gwat.12874
Learn more about Groundwater at: https://www.ngwa.org/publications-and-news/journals/Groundwater
For consultation regarding estimation of interstitial velocity, contact Haley Schneider at This email address is being protected from spambots. You need JavaScript enabled to view it.
Learn more about Haley: https://www.linkedin.com/in/haley-schneider-phd-eit-6602a215a/