An Inexpensive Multilevel Array of Sensors for Direct Ground Water Velocity Measurement

Abstract

The point velocity probe (PVP) is an instrument capable of measuring ground water velocity in situ at the centimeter scale. It is based on detecting an electrically conductive tracer transported by ground water around the perimeter of the cylindrical probe. PVPs are easily constructed from inexpensive materials and can be deployed as a single sensor or in multilevel arrays. A multilevel array of these instruments, consisting of four PVPs stacked vertically on each of five stands, was installed as a fence within a sheet‐pile alleyway at the Canadian Forces Base Borden test site in Ontario, Canada. The data from the fence revealed notable velocity variations both spatially and temporally. Ground water velocity data of these kinds are likely to be valuable for permeable reactive barrier design and assessment, regulatory compliance assessments, and a variety of research level investigations concerned with local flow phenomena.

Field GPR monitoring of biostimulation in saturated porous media

“…In this investigation, we utilized PVPs in a multilevel 2D array (or fence) to monitor groundwater velocity changes over the duration of the experiment. The theory, deployment, and mechanics of the PVP work completed in this study are presented in Devlin et al (2009) and Schillig et al (2011).…”

Estimates of Horizontal Groundwater Flow Velocities in Boreholes

“…The problem of characterizing regional onedimensional flow based on measurements from an observation borehole without pumping has been studied extensively (e.g., Drost et al 1968;Kearl 1997;Devlin et al 2009;Osorno et al 2018). Methods to estimate the natural horizontal Darcy flux in the aquifer based on borehole observations can be classified in two groups: flux-based methods (e.g., dilution tests, Permeable Flux Meters) and in-hole velocity methods (e.g., Colloidal Borescope, Heat Pulse Flowmeter, Acoustic Doppler Flowmeter, In-Well Point Velocity Probe).…”

“…As an alternative to borehole observations, the Point Velocity Probe (PVP) (Labaky et al 2007;Devlin et al 2009) is a direct push method in which water velocity magnitude v ∞ and direction can be directly estimated from mini tracer tests performed around the measuring device without any assumption on the aquifer porosity. PVPs have been tested in several lab and field scale experiments with promising results (Labaky et al 2009;Devlin et al 2011;Schillig et al 2016;Gibson and Devlin 2017).…”

Estimation of water velocities in boreholes using a new passive flowmeter

“…it is not a flowmeter, but can be inserted into an aquifer of unconsolidated and non-cohesive materials (such as sand or gravel), before measurements of the filtration velocity are taken. The point-velocity method was successfully applied both in the laboratory and at the field scale (Borden site test, Ontario, Canada; Devlin et al 2009) for groundwater filtration velocities ranging from 0.8 to 86 cm d -1 . Simultaneous measurements in different locations may allow very accurate aquifer characterization whilst avoiding expensive field tracer tests.…”

“…Recently, Devlin et al (2009) undertook the development of a specific apparatus using polyvinyl chloride (PVC) capable of deriving the seepage groundwater velocity for a wide range of measurements and at centimetre depth intervals. This interesting point-velocity method, which is based on water-specific conductance measurements, was derived from a previous prototype of stainless steel proposed by Labaky et al (2007).…”