J.F. Devlin

J.F. Devlin
University of Kansas | KU · Department of Geology

About

110
Publications
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Introduction
J.F. Devlin currently works at the Department of Geology, University of Kansas. J.F. does research in Hydrogeology and Geochemistry. Recent projects include work on the performance of zero valent iron in reactive barriers, in situ denitrification, and the development of tools for the measurement of groundwater velocity. The latter work has led to devices able to quantify groundwater flow with or without wells, and flow across the groundwater-surface water interface.

Publications

Publications (110)
Article
Flow in a fractured rock aquifer beneath the Edwards Air Force Base in California was characterized by depth profiling two wells with In-Well Point Velocity Probes (IWPVPs). The probes, which were originally designed for use in porous media wells, were optimized for use in fractured rock wells and to meet several challenges including: sampling dept...
Article
Full-text available
In 1986, a seminal data set from the Canadian Forces Base (C.F.B.) Borden aquifer, Ontario, Canada, was published, illustrating, in unprecedented detail, the spatial distribution of hydraulic conductivity (K). Among many contributions attached to that data set was a geostatistical examination of field‐based data for comparison with theoretical pred...
Article
The In-Well Point Velocity Probe (IWPVP) was originally developed for use in screened porous media wells. The tool can characterize small-scale aquifer heterogeneity from wells that have been carefully developed to ensure an open screen and good hydraulic connection with the surrounding aquifer. This capability led to the hypothesis that the IWPVP...
Article
The Horizontal Reactive Media Treatment Well (HRX Well®) is a technology capable of collecting and treating groundwater passively. To monitor the internal flow rate, ensuring it remains at an acceptable level and maintains the desired capture zone size in the aquifer, Point Velocity Probes (PVPs) were adapted for the task. The modified PVP was asse...
Article
In situ treatment usually requires contact between an injected reagent and target contaminant to realize mass removal from source zones and plumes. Despite significant site characterization efforts, unknown heterogeneities that exist at all spatial scales often hinder prediction of the distribution of injected reagents. To provide remediation pract...
Article
Attenuation processes of chlorinated ethenes in complex near-stream systems result in site-specific outcomes of great importance for risk assessment of contaminated sites. Additional interdisciplinary and comprehensive in situ research are required to enhance process understanding in these systems. In this study, several methods were combined in a...
Article
Full-text available
The horizontal reactive media treatment well (HRX Well®) uses directionally drilled horizontal wells filled with a treatment media to induce flow‐focusing behavior created by the well‐to‐aquifer permeability contrast to passively capture proportionally large volumes of groundwater. Groundwater is treated in‐situ as it flows through the HRX Well and...
Article
Grain size analysis and permeametry are common methods for estimating the hydraulic conductivity (K) of porous media. It is well known that these methods have limited accuracy when they are used to characterize natural sediments. However, hydrogeological research has increasingly introduced technologies dependent on engineered porous media that may...
Presentation
Initial findings on the development of a new framework for high-resolution site characterization and monitoring using the PVP suite of tools for better risk assesment using a mass-flux based approach
Article
A comparison of tools for measuring discharge rates in a sandy streambed was conducted along a transect near the north bank of the Grindsted å (stream). Four tools were evaluated at six locations spaced 3 m apart in the stream: mini‐piezometers, streambed point velocity probes (SBPVPs), temperature profilers, and seepage meters. Comparison of the m...
Article
A treatment pond, with an engineered bed that served as a passive Vertical Flow Bioreactor (VFBR), was operated as part of a passive sequenced treatment system for the removal of metals form groundwater at the Mayer Ranch in Commerce, Oklahoma. The groundwater was contaminated by mining activities in west Commerce and discharges at this location oc...
Article
Full-text available
A new in situ remediation concept termed a Horizontal Reactive Media Treatment Well (HRX Well®) is presented that utilizes a horizontal well filled with reactive media to passively treat contaminated groundwater in situ. The approach involves the use of a large‐diameter directionally drilled horizontal well filled with solid reactive media installe...
Conference Paper
Full-text available
A new in-situ remediation concept termed a Horizontal Reactive Media Treatment Well (HRX Well®) is presented that utilizes horizontal wells filled with reactive media to passively treat contaminated groundwater in-situ. The approach involves the use of large-diameter directionally-drilled horizontal wells filled with solid reactive media generally...
Article
Full-text available
The streambed point velocity probe (SBPVP) measures in situ groundwater velocities at the groundwater-surface water interface without reliance on hydraulic conductivity, porosity, or hydraulic gradient information. The tool operates on the basis of a mini-tracer test that occurs on the probe surface. The SBPVP was used in a meander of the Grindsted...
Article
The In-Well Point Velocity Probe (IWPVP) is a novel device designed for obtaining rapid, initial measurements of groundwater velocity at the centimeter-scale using a standard monitoring well to access the subsurface. IWPVP measurements of groundwater speed are quantified on the basis of a mini-tracer test that is conducted within the body of the pr...
Article
To gain insight into the processes of transformations in zero-valent iron systems, electrolytic iron (EI) has been used as a surrogate for the commercial products actually used in barriers. This substitution facilitates mechanistic studies, but may not be fully representative of all the relevant processes at work in groundwater remediation. To addr...
Article
The point-velocity probe (PVP) quantifies groundwater speed and flow direction, i.e., velocity, at the centimeter scale. The first probe designs required that the flow direction be known a priori, within about 100° in order to position the probe during installation. This study introduces and assesses a '360° PVP' that measures flow from any directi...
Article
Distributions of flow across the groundwater-surface water interface should be expected to be as complex as the geologic deposits associated with stream or lake beds and their underlying aquifers. In these environments, the conventional Darcy-based method of characterizing flow systems (near streams) has significant limitations, including reliance...
Article
For the purposes of risk mitigation and remediation design, Darcy's Law calculations, that are typically used to estimate flow direction and magnitude, can be usefully supplemented with more direct measurements. The point velocity probe (PVP), which measures groundwater velocity by conducting a mini-tracer test across a cylindrical probe surface, w...
Article
HydrogeoEstimatorXL is a free software tool for the interpretation of flow systems based on spatial hydrogeological field data from multi-well networks. It runs on the familiar Excel spreadsheet platform. The program accepts well location coordinates and hydraulic head data, and returns an analysis of the area flow system in two dimensions based on...
Article
Point velocity probes (PVPs) are dedicated, relatively low-cost instruments for measuring groundwater speed and direction in non-cohesive, unconsolidated porous media aquifers. They have been used to evaluate groundwater velocity in groundwater treatment zones, glacial outwash aquifers, and within streambanks to assist with the assessment of ground...
Article
Diluting granular iron with sand is a common practice performed to minimize clogging and to reduce the cost of permeable reactive barrier (PRB) installations. This study used a pore-scale image analysis technique and a reanalysis of previously published data to test the hypothesis of Bi et al. (2009) that the mixing of 15% by weight sand with a com...
Article
Small-scale point velocity probe (PVP)-derived velocities were compared to conventional large-scale velocity estimates from Darcy calculations and tracer tests, and the possibility of upscaling PVP data to match the other velocity estimates was evaluated. Hydraulic conductivity was estimated from grain-size data derived from cores, and single-well...
Article
Full-text available
For over a century, hydrogeologists have estimated hydraulic conductivity (K) from grain-size distribution curves. The benefits of the practice are simplicity, cost, and a means of identifying spatial variations in K. Many techniques have been developed over the years, but all suffer from similar shortcomings: no accounting of heterogeneity within...
Article
Nitrate in groundwater and surface water is among the most common contamination problems in the world. Efforts to reduce the loss of excess nutrients at the regional scale currently focus on Best Management Practices (BMPs) designed to facilitate the optimal use of fertilizers, adjusted for specific site conditions. Performance monitoring of region...
Article
Hydrogeological setting has profound effects on microbial effectiveness in in situ treatment.•We design and implement an in situ denitrification method to reduce groundwater nitrate concentrations near impacted wells.•Field challenges included natural aquifer heterogeneity and aerobic groundwater conditions.•Results indicate significant nitrate mas...
Article
The concept of equivalent freshwater head was adapted to predict the conditions under which density-driven flow would adversely impact measured groundwater velocities using point velocity probes (PVPs). Theoretically, vertical flow will result from any density contrast between the PVP tracer and the groundwater. However, laboratory testing of trace...
Article
Full-text available
Commercial granular iron (GI) is light steel that is used in Permeable Reactive Barriers (PRBs). Investigations into the reactivity of GI have focused on its chemical nature and relatively little direct work has been done to account for the effects of grain shape and packing. Both of these factors are expected to influence available grain surface a...
Article
The selection of a suitable kinetic model to investigate the reaction rate of a contaminant with granular iron (GI) is essential to optimize the permeable reactive barrier (PRB) performance in terms of its reactivity. The newly developed Kinetic Iron Model (KIM) determines the surface rate constant (k) and sorption parameters (Cmax & J) which were...
Article
AbstractA benchtop sandbox constructed from nested storage tanks (NeSTs), was assembled for studying flow and transport in porous media. Molded plastic storage containers, purchased at a department store, were modified to fashion the tanks. The remaining construction materials were also inexpensive and the NeST design made it virtually leak‐proof....
Article
The Domenico solution is a heuristic simplification of a solution to the transport equation. Although there is a growing consensus that the Domenico solution is undesirable for use in professional and research applications due to departures from exact solutions under certain conditions, it behaves well under conditions suitable for instruction. Mor...
Article
Time-lapse borehole radar was used to monitor a sandy aquifer with dielectric property changes hypothesized to result from biomass growth and biodegradation of hydrocarbons. A blend of gasoline and ethanol was released below the water table at Canadian Forces Base (CFB) Borden, Canada, and a source of oxygen was used for cyclic stimulation of micro...
Conference Paper
This study was conducted to determine the repeatability of groundwater velocity estimates using the 2-inch diameter, prototype-printer Point Velocity Probe (PVP). PVPs are relatively new instruments used to measure groundwater velocities in support of treatment efforts and contaminated site characterization problems. This study is important because...
Article
Three projects involving point velocity probes (PVPs) illustrate the advantages of direct groundwater velocity measurements. In the first, a glacial till and outwash aquifer was characterized using conventional methods and multilevel PVPs for designing a bioremediation program. The PVPs revealed a highly conductive zone that dominated the transport...
Article
Localized, transient heterogeneity was studied in a sand aquifer undergoing benzene, toluene, ethylbenzene, and xylene bioremediation using a novel array of multilevel, in situ point velocity probes (PVPs). The experiment was conducted within a sheet-pile alleyway to maintain a constant average flow direction through time. The PVPs measured changes...
Article
Recent studies of the geophysical signatures of biological processes in earth environments have resulted in the emergent field of ``biogeophysics''. The ability to monitor remotely and to quantify active biological processes in the subsurface can have transformative implications to a wide range of investigations, including the bioremediation of con...
Article
In this study, we evaluate the use of ground-penetrating radar (GPR) to investigate the effects of bacterial activity in water saturated sand. A 90-day laboratory-scale controlled experiment was conducted in a flow-through polycarbonate sandbox using groundwater from the Kansas River alluvial aquifer as inoculum. After 40 days of collecting baselin...
Article
To better understand controls on observed trichloroethene (TCE) reaction rates in granular iron permeable reactive barriers, column experiments were conducted with different iron loadings. Using a reactive transport model and the Kinetic Iron Model (KIM), unique estimates of Langmuir sorption parameters for both the nonreactive and reactive sites,...
Article
Recent studies of the geophysical signatures of biological processes in earth environments have resulted in the emergent field of "biogeophysics". The ability to monitor remotely and to quantify active biological processes in the subsurface can have transformative implications to a wide range of investigations, including the bioremediation of conta...
Article
Batch experiments were conducted with granular iron (Fe(0)) in pH 10 solutions of 4-chloronitrobenzene (4ClNB) and mixed anions (ClO4-, SO(2-), and HCO3-). In pure solutions, SO4(2-) is known to enhance Fe(0) reactivity, whereas HCO3- has been variously reported to depress Fe(0) reactivity or enhance it ClO4- has been found to be minimally reactive...
Article
With increasing interest in reactive porous media for groundwater remediation, such as granular iron, kinetic rate equations based on the Langmuir-Hinshelwood (L-H) assumptions have proven useful. Three parameters describe L-H kinetics: the two Langmuir sorption parameters, J and Cmax, and the first order rate constant, k. Unfortunately, the Cmax a...
Article
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 senso...
Article
A substantial cost of granular iron permeable reactive barriers is that of the granular iron itself. Cutting the iron with sand can reduce costs, but several performance issues arise. In particular, reaction rates are expected to decline as the percentage of iron in the blend is diminished. This might occur simply as a function of iron content, or...
Conference Paper
* An important role of models in the ground water field is in their service as facilitators for information exchange between rigorous theoretical science and the job of quantitatively applying hydrogeology to solve real-world problems and make predictions. The widespread use of codes such as MODFLOW and PHREEQC by practitioners not fluent in the co...
Article
Full-text available
Field testing of a new tool for measuring groundwater velocities at the centimeter scale, the point velocity probe (PVP), was undertaken at Canadian Forces Base, Borden, Ontario, Canada. The measurements were performed in a sheet pile-bounded alleyway in which bulk flow rate and direction could be controlled. PVP velocities were compared with those...
Conference Paper
At any one time the majority of continental settings are subaerially exposed and modified by pedogenic processes that include bioturbation, produced by soil biota as one of the five soil-forming factors. Resulting fabrics are ichnopedologic in nature and have unique biophysicochemical properties compared to sediments in subaqueous settings. Three m...
Article
A novel method of measuring small-scale groundwater velocities in unconsolidated noncohesive media uses the travel time of a tracer pulse between an injection port and two detectors located on the surface of a cylindrical probe, called a point-velocity probe (PVP), as the basis for velocity estimation. The direction and magnitude of the water veloc...
Article
A detailed laboratory tank experiment was conducted, as follow-up to preliminary findings from an earlier experiment, to investigate the effects of microbial growth on groundwater flow, and the sensitivity of GPR to measure changes in the aquifer resulting from that growth. The preliminary work involved the biostimulation of saturated sand in a Ple...
Article
Field observations of groundwater velocity using point velocity probes (PVPs) and aquifer dielectric properties using ground penetrating radar (GPR) were made in a bioremediating, gasoline contaminated aquifer to which dissolved oxygen was introduced using Oxygen Release Compound (ORC®). PVPs are sensitive to changes in groundwater flow; whereas GP...
Article
Aquifer heterogeneity can place severe restrictions on deterministic modeling of contaminant fate and transport. One response to this is to collect geostatistical data so that multiple realizations of the aquifer can be simulated and probabilities of various transport scenarios estimated. However, both the deterministic and stochastic modeling appr...
Article
In the practice of aquifer remediation, groundwater velocity is an essential parameter for determining contaminant fate and transport, and calculating residence times for passive treatment technologies such as reactive barriers. Over the past decade, there has developed an increased reliance on natural attenuation of various contaminants in porous...
Article
A pilot-scale test of an in situ denitrification scheme was undertaken to assess an adaptation of the nutrient injection wall (NIW) technology for treating a deep (30-40 m) nitrate contamination problem (N-NO(-)(3) ~ 10-12 mg/L). The adaptation is called the Cross-Injection Scheme (CIS). It duplicates the NIW method without a wall; wells are instal...
Article
During the design of a natural gradient tracer experiment, it was noticed that the hydraulic gradient was too small to measure reliably on an approximately 500-m(2) site. Additional wells were installed to increase the monitored area to 26,500 m(2), and wells were instrumented with pressure transducers. The resulting monitoring system was capable o...
Article
The glass encased magnet (GEM) batch reactor was designed to permit reactivity studies of granular iron with good mixing, and minimal abrasion. This study compared the GEM reactor with two conventional batch test designs (for granular iron studies). In the GEM reactor experiments, the reduction of 4-chloronitrobenzene with Connelly granular iron wa...
Article
Elevated nitrate concentrations within a municipal water supply aquifer led to pilot testing of a field-scale, in situ denitrification technology based on carbon substrate injections. In advance of the pilot test, detailed characterization of the site was undertaken. The aquifer consisted of complex, discontinuous and interstratified silt, sand and...
Article
Small-scale heterogeneities overlooked in relatively homogeneous aquifers may introduce significant changes in groundwater flow. The work presented here employs two independent methods for high-resolution characterization of the hydrostratigraphy of the Borden aquifer in Ontario, Canada: a) borehole radar, and b) multi-level Point Velocity Probes (...
Article
The need for objective parameter estimates is common in hydrogeology. The simplex optimization algorithm provides a fast, simple, and versatile method for making such estimates when used to minimize the residuals sum of squares between calculated and observed data points. Examples of the method applied to Pick's Second Law, the advection dispersion...
Article
Full-text available
Sustainability and sustainable pumping are two different concepts that are often used interchangeably. The latter term refers to a pumping rate that can be maintained indefinitely without mining an aquifer, whereas the former term is broader and concerns such issues as ecology and water quality, among others, in addition to sustainable pumping. Ano...
Article
The relative effects of sulfate (SO4(2-)), chloride (Cl-), nitrate (NO3-), and bicarbonate (HCO3-) (8 mM ionic strength solutions, adjusted to pH 10) on the reactivity of Master Builders iron was investigated using a low-abrasion batch reactor with a glass-encased magnet (GEM). Reactivity of the granular iron surface was assessed by measuring the r...
Article
Two nitroaromatic compounds, 4ClNB and 4AcNB, were reduced with granular iron in batch tests and columns tests with a range of initial concentrations from about 20 μM to 400 μM. The batch test data were interpreted using the Langmuir-Hinshelwood rate law to obtain an estimate of the sorption parameter J, and the column test data were interpreted wi...
Article
In naturally occurring flow systems the hydraulic gradient may be small, often less than 0.002- 0.001. These small gradients are hard to measure accurately at all scales. On regional flow maps, the accuracy of the head contour lines and the gradient is usually determined by the accuracy of the elevation of the top of the casing and of the well loca...
Article
A mixture of chlorinated solvents (about 0.5-10 mg/l), including tetrachloroethene (PCE) and carbon tetrachloride (CT), together with a petroleum hydrocarbon, toluene (TOL), were introduced into a 24 m long x 2 m wide x 3 m deep isolated section (henceforth called a gate) of the Borden aquifer and subjected to sequential in situ treatment. An ident...
Article
The remediation of nitroaromatic contaminated groundwater is sometimes difficult because nitroaromatic compounds are resistant to biodegradation and, when they do transform, the degradation of the products may also be incomplete. A simple nitroaromatic compound, nitrobenzene, was chosen to assess the feasibility of an in situ multi-zone treatment s...
Article
An energy balance shows that geomorphological processes are driven by an energy source more powerful than the geological processes that raise the continents. In addition, energy fluxes for the entire Earth are calculated from several energy sources including enery from the Sun, Esolar, geothermal energy, Egeothermal, based primarily on heat product...
Article
Hydraulic gradients from planar water tables, or piezometric surfaces, and horizontal flow regimes can be quickly and conveniently calculated from data sets involving numerous wells. The matrix-solving functions of a modem spreadsheet program (Excel) were used to determine the equation of a water-table plane, Ax + By + Cz - D = 0, and the equation...
Article
An experiment to investigate the natural attenuation of three volatile organic compounds, toluene, carbon tetrachloride, and tetrachloroethene (~1-10 mg L-1) was performed in a 3 m deep, sandy aquifer isolated within a 24 m long, 2 m wide, three-sided sheet pile alleyway (hereafter referred to as the gate). A constant flow was maintained in the tes...
Article
Full-text available
The purpose of this study was to compare several hydrogeologically based methods of evaluating natural attenuation in a controlled setting in situ, and then contrast the estimated attenuation rates with those from an in situ bio­ remediation experiment, performed in an identical fiinnel-and-gate structure. Three volatile organic chemicals, carbon t...
Article
A simple dissolution model based on Raoult's Law was used to derive a log-linear equation for the estimation of multicomponent nonaqueous-phase liquid (NAPL) mass in porous media. The analysis, referred to here as the ratio mass estimation (RME) method, requires aqueous concentration ratios for two components of the NAPL mixture as well as their pu...
Article
A simple dissolution model based on Raoult's Law was used to derive a log-linear equation for the estimation of multicomponent nonaqueous-phase liquid (NAPL) mass in porous media. The analysis, referred to here as the ratio mass estimation (RME) method, requires aqueous concentration ratios for two components of the NAPL mixture as well as their pu...