Groundwater is a major source of potable water in British Columbia and is used extensively in many areas of the province. However, despite the importance of the resource, groundwater development and use are subject to few constraints. Reliance on common law rights has contributed to the development of problems of overuse and contamination of the resource in some parts of British Columbia. The objectives of the thesis are to provide an overview study of groundwater and to develop a set of recommendations for improving the management of groundwater in British Columbia. Most of the information used in the thesis is from primary and secondary written material in the fields of law, economics, hydrogeology, and natural resources management. Some primary written and verbal material was obtained from the British Columbia Ministry of Environment staff. Several groundwater management and regulation schemes which have been recommended in the literature or adopted in other regions of western North America are reviewed and then assessed according to the criteria of feasibility, equity, effectiveness, and economic efficiency. The evaluation of these alternatives forms the basis of the recommendations for management of British Columbia's groundwater. The thesis recommends that, in areas where groundwater problems have developed or are likely to occur, clearly defined groundwater rights be established by the Comptroller of Water Rights. The Comptroller would conduct hearings into groundwater supply and demand, decide upon a collective withdrawal rate for each area, and then assign rights to individual users to pump water at specified rates. The thesis further recommends that, once the allocation of rights has been made, the rights would be marketable. / Applied Science, Faculty of / Community and Regional Planning (SCARP), School of / Graduate

A stochastic analysis of groundwater flow leads to probability distributions on the predicted hydraulic head values. This variability reflects our uncertainty in the system being modeled due to the spatial heterogeneity of hydraulic conductivity. Monte Carlo techniques can be used to estimate the head distributions. This approach relies on the repetitive generation of discrete-block conductivity realizations. In this study, steady state flow through one and two-dimensional flow domains is investigated. A space law based on a first order, nearest neighbour stochastic process model is used to generate the multilateral spatial dependence in the hydraulic conductivity values within the block structure. This allows consideration of both statistically isotropic and anisotropic autocorrelation functions. It is shown that the probability distribution of hydraulic head and the head gradient or the flux across the boundaries of the flow domain, must be interpreted in terms of: 1) The spatial variation of expected head gradients. 2) The standard deviation in the conductivity distribution. 3) The ratio of the integral scale of the autocorrelation function for conductivity to the distance between boundaries on the flow domain. 4) The arrangement of stationary units within the flow domain. The standard deviations in hydraulic head increase with an increase in either the conductivity standard deviation or the strength of the correlation between neighbouring conductivity values. Provided the integral scales of the medium are preserved, the standard deviations in head show only a minor dependence on the discretization interval. The head standard deviations are approximately halved in a two-dimensional model from those in a one-dimensional model with an equivalent space law. Spatial trends in the mean conductivity can considerably alter the magnitude and spatial variation in the hydraulic head standard deviations. The geometric mean has been suggested by others as a suitable effective conductivity in a heterogeneous two-dimensional flow domain. This study shows that only in the case of uniform flow through a single stationary unit is this concept valid. If the mean gradient field is nonuniform, or if the mean conductivity has a spatial trend, predictions based on the geometric mean do not satisfy the necessary equivalence criteria. Direct comparisons cannot be made, but the Monte Carlo and spectral approaches to the solution of the stochastic flow equations predict a similar behavior. A first order, nearest neighbour model is matched to a data set collected from a relatively uniform but stratified, unconsolidated sand deposit. The data show statistically anisotropic autocorrelation functions, both in the integral scale and in the functional form of the correlation. A broader class of spatial models may need to be considered to describe the cyclic behavior of sedimentary sequences. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Nanoscale zero-valent iron (NZVI) particles were encapsulated in calcium alginate capsules for application in environmental remediation. TCE degradation rates for encapsulated and bare NZVI were similar indicating no adverse effects of encapsulation on degradation kinetics. Microorganisms were separately encapsulated and used along with encapsulated NZVI and co-encapsulated in calcium alginate capsules. Batch experiments were performed to test the efficacy of the combined iron-Pseudomonas sp. (PpF1) system. The combined system removed 100% TCE over the first three hours of the experiment followed by 70% TCE removal post TCE re-dosing. Complete reduction of TCE was achieved by NZVI between 0-3 h and the second phase of treatment (3-36 h) was mostly achieved by microorganisms. Experiments conducted with co-encapsulated NZVI-D.BAV1 achieved 100% TCE removal. During the first three hours of the experiment 100% TCE removal was achieved by NZVI, and 100% removal was achieved post re-dosing where D.BAV1 accomplished the treatment. / Department of Civil Engineering, North Dakota State University

Please read the abstract in the section 00front of this document / Dissertation (MSc (Engineering Geology))--University of Pretoria, 2000. / Geology / unrestricted

Groundwater systems hidden beneath oceans and ice sheets impact modern Earth processes and hold information about past Earth environments. However, the nature, distribution, and architecture of these systems, as well as the mechanisms by which they influence their surrounding environments, remain poorly understood. This dissertation applies electromagnetic (EM) geophysical methods to investigate the spatial character and salinity content of previously unmapped submarine and subglacial hydrogeologic systems. Chapter 2 of this dissertation examines the first large-scale EM imaging of submarine aquifer systems extending up to 90 km offshore on the U.S. Atlantic margin. Magnetotelluric (MT) and controlled source electromagnetic data collected offshore New Jersey and Martha’s Vineyard, Massachusetts, show that low-salinity groundwater contained in continental shelf sediments continuously extends from the coast out to 90 km offshore. The EM imaging offshore New Jersey agrees with observed low-salinity porewater anomalies from drill cores and shows the spatial extent and continuity of these anomalies. Offshore Martha’s Vineyard, our results provide the first observational constraints on the distribution of offshore groundwater. Combining the EM results with seismic reflection imaging provides further insight into the architecture of offshore groundwater systems, as seismically mapped confining units and clinoforms correspond to the vertical and lateral boundaries of low-salinity groundwater distributions, respectively. We estimate there is 2800 km³ of low-salinity groundwater within the aquifer system between New Jersey and Martha’s Vineyard. This aquifer system is representative of a global phenomenon, as it has been estimated that Earth’s passive margins contain 500,000 km³ of low-salinity groundwater. This dissertation demonstrates that these groundwater systems can be efficiently mapped using marine electromagnetic imaging. This mapping is important for understanding past oceanic and climatic conditions, the delivery of nutrients from the continents to the ocean, physical and biogeochemical continental shelf processes, and water resources globally. Chapters 3 - 6 discuss the first polar MT study focused on investigating the upper 5 km of the subglacial environment of an ice stream and demonstrates that MT is an effective tool for mapping subglacial hydrogeologic systems. We collected MT data on Whillans Ice Plain (WIP), West Antarctica, a region of fast flowing ice that hosts an interconnected network of active subglacial lakes that cyclically fill and drain on monthly to yearly timescales, and eventually drain into the Southern Ocean beneath Ross Ice Shelf. Currently, at WIP and other ice streams, water volumes and exchanges have only been accounted for at the ice-bed interface and within the top 10 m of basal sediment; however, deeper groundwater systems are likely active components of the subglacial hydrologic system and may modulate ice flow. We collected MT data in order characterize subglacial groundwater distribution and salinity beneath an active lake, Whillans Subglacial Lake (hereafter referred to as SLW for historical reasons), and the Whillans Grounding Zone (WGZ), where SLW is thought to drain into the Southern Ocean. We collected one additional station at Mercer Subglacial Lake (hereafter referred to as SLM for historical reasons) to evaluate potential geologic and hydrologic variations across WIP. Chapter 3 discusses the importance of subglacial hydrology and how it is parameterized in models. I also introduce previous glaciological studies done within and around WIP, as well detailed geophysical and direct subglacial access studies at SLW and WGZ. Chapter 4, covers the acquisition and processing of MT data on WIP and examines noise identification and removal techniques. I review existing methods for acquiring MT data in polar surveys and develop new methods that are specific to rapid, short-term polar MT surveys, but may also be applied to longer term surveys. Wind speeds as low as 5 knots introduce broadband noise into the electric field measurements, through the stream of electrically charged ice particles carried by wind. However, this noise may be removed through frequency-dependent wind speed based data editing. Magnetic field data are less affected by wind noise and therefore high quality magnetic field data may be collected during times when wind speeds do not allow for the collection of high quality electric field data. The results from this chapter can be used to guide and optimize future polar MT surveys. Chapter 5 evaluates the magnetotelluric data and 2-D inversion results from the data collected on WIP. The MT data vary laterally across each survey region, suggesting lateral hydrologic and geologic variations. Overall, the data trends at SLW and WGZ are fairly similar, while the single station collected at SLM, is quite different, suggesting there are significant geologic and hydrologic changes within WIP. The inversion results indicate that there is a conductive region within the top 350 to 2000 m of the subglacial environment, which is interpreted to be water saturated sediments. This feature is underlain by a more resistive region, which we interpret to represent bedrock. At WGZ, the MT derived depth to bedrock agrees well with a geologic model of bedrock from a previous ground-based gravity survey in the same location. Chapter 6 uses the resistivity models from Chapter 5 to estimate groundwater volumes and salinities at SLW and WGZ. At both survey locations, this analysis requires extensive saline groundwater systems that extend > 1 km below the ice surface. Our results suggest an “open system” in which deep groundwater may be exchanged with basal water. Directly beneath SLW, we estimate the volume of groundwater is over 40 times greater than the volume of water held in the lake, suggesting that WIP and other Antarctic sedimentary basins likely contain groundwater that represents a significant component of subglacial hydrologic budgets. This mapping of subglacial groundwater volume and salinity may be used to improve understanding of coupled groundwater and ice dynamics, as well as provide insight into observed geothermal variations. It also has implications for biogeochemical reactions throughout the sediment column that may play a role in sub-ice-sheet nutrient cycling.

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Groundwater contaminated by leachate from historic landfills, closed and typically without liners or leachate-collection systems, can potentially discharge to surrounding surface waters and impair their ecological communities. However, few studies have focused on emerging contaminants (e.g., per- and poly-fluoroalkyl substances (PFAS)), inputs to non-flowing water bodies, and exposure across the various ecological zones. The objective of this study was to better understand the ecological risk posed by a historic landfill plume discharging to a nearby pond, and how the pond’s ecosystem may be affected by potential spatio-temporal variability in contaminant concentrations and contaminant discharge. The site contained an artificial pond 40m west of a historic sanitation landfill and was monitored for ~1 year. Seasonal samples of shallow groundwater analyzed for standard chemistry plus artificial sweeteners and PFAS revealed a large and seasonally stable plume footprint in the pond and relatively constant exposure to the endobenthic zone (within sediments), with some constituents at potentially toxic concentrations. Elevated electrical conductivity measured just above (~1 cm) the sediment bed indicated exposure to the epibenthic zone, with greater exposure associated with higher groundwater fluxes at night, after rain and melt events, and in winter. It is speculated that terrestrial evapotranspiration and pond evaporation play a role in these temporal patterns. Estimated contaminant mass fluxes into the pond using contaminant and temperature-based flux data showed spatial variability within the plume footprint and seasonal patterns. Concentrations in the pond water showed exposure to pelagic organisms was consistent for chloride and saccharin (and likely PFAS), but varied seasonally for nitrate and ammonium, with all at lower concentrations compared to the endobenthic and epibenthic zones. This study revealed significant and variable ecological exposure from a landfill leachate plume discharging to a pond and provides guidance to landfill operators on improved monitoring protocols for such sites. / Thesis / Master of Science (MSc) / Groundwater contaminated by historic landfills, closed and typically without liners or leachate-collection systems, can potentially discharge to surrounding surface waters, threatening their ecological communities. The objective of this study was to better understand the ecological risk posed by a historic landfill plume discharging to a nearby pond, and how this might vary spatially and temporally. The study site contained an artificial pond 40m west of a historic sanitation landfill and was monitored for contaminant concentrations and contaminant discharge for ~1 year. Elevated concentrations of leachate contaminants were relatively steady within the sediments (endobenthic zone) and similar across the contaminant discharge area but varied substantially in space and time (higher at night, after events, in the winter) at the pond bed (epibenthic zone), while the patterns differed by contaminant in the surface water above (pelagic zone). These findings can provide insights into improved monitoring and protection of ecosystems at landfill sites.

A research report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfilment of the requirements for the degree of Master of Science in Mining Engineering / Slope stability is critical for final wall in open pit mining operations. Not only is slope failure costly to manage, it might also be accompanied by loss of lives. Factor of safety is very critical during the slope design phase, however, the execution of the design is as important as the design phase itself. Among the many factors affecting stability of highwalls, geology, groundwater and blasting are at the top of the list. This research takes a kinematic stability analysis approach and investigates the possible failure mechanisms in the phyllites rock mass. The data collected from the structural geological mapping along with the window mapping classifies the rock as fair to good rock. The induced failures causing reduced catchment berms and consequently longer bench heights are largely influenced by the prevailing geological conditions, presence of groundwater seeping through the highwall and quality of blasting being conducted. Amongst the factors influencing slope stability, blasting is the only controllable one. Therefore, adjustments to the blast designs need to be made as mining progresses keeping in mind that rock is not homogeneous. Wall control blasting techniques should be continuously adjusted depending on the Rock Mass Rating or blastability index of the rock mass in that area. Hydrogeological testing of boreholes including Packer testing was conducted in order to estimate the hydraulic conductivity. Adjustments to blast designs were made taking due cognizance of the geological conditions as well as presence of ground water. Adjustments to the wall control blasting techniques need to be made as mining progresses through the different rock mass zones. A few blasts on the lower levels (mining benches below 1112RL) were conducted which saw an improvement in the quality of the highwall. Further adjustments to blast designs need to be made as the pit gets deeper and as geological conditions vary. / NG (2020)

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