Decision Models For Groundwater Pollution Control And Remediation

A collection of invited contributions by researchers who have made significant contributions to this important field, this book covers recent advances and also provides insight into possible future developments.

This book is the documented result of an expert workshop, Modeling and Management of Emerging Environmental Issues, held at Penn State University. This event assembled four panels of modeling experts from the U.S. and Canada to discuss modeling technology development and application in order to promote sound and cost-effective environmental decision-making. This thorough analysis provides an overview on the state-of-the-art in current practice and identifies emerging research and development trends within modeling technology. Each of the discussions considers not only technical issues, but regulatory and cost factors as well.

The protection of groundwater resources has emerged in recent years as a high priority topic on the agenda of many countries. In responding to the growing concern over deteriorating groundwater quality, many countries are developing a comprehensive regulatory framework for the management of subsurface water resources with management referring to both quantity and quality aspects. Within this framework, groundwater models are rapidly coming to playa central role in the development of protection and rehabilitation strategies. These models provide forecasts of the future state of the groundwater aquifer systems and/or the unsaturated zone in response to proposed management initiatives. For example, models will predict the effects of implementing a proposed management scheme on water levels and on the transport and fate of pollutants. The models are now used in the formulation of policies and regulations, the issuing of permits, design of monitoring and data collection systems, and the development of enforcement actions. The growth in the use of these sophisticated tools has led to many unforeseen problems in groundwater management. Lingering issues include reliability of codes, quality assurance in model development and applications, efficient utiliza tion of human and material resources, technology transfer and training. Some issues have legal ramifications, as in cases where the applications of models have been contested in courts.

In recent years the analysis, control, preservation, remediation and correct management of underground resources have received a growing attention in a variety of sectors, including industrial, professional and academic environments. The volume describes new developments in both applied research and design technology to maintain sustainability of a vital resource (groundwater) which is continuously threatened by contamination resulting from solid waste disposal operations, site reutilization, intensive extraction, accidental leakage of spill in working installations and non-point source pollution in agriculture. It is directed to managers, professionals, and researchers working in any of the areas concerned with the control, prediction, and remediation of soil and groundwater contamination.

In the past decades, environmental scientists, economists and physicists have been juggling critical issues within environmental strategies and environmental management styles in order to find a feasible medium between limited resources, long term demands and objectives, and interest groups. In the search for best management alternatives, practice has undergone a pendulum swing between stages that can be characterised as frontier economics, radical environmentalism, resource management/allocation, selective environmentalism and sustainable environmental management. The next stage of management must answer such questions as: `Can there be a global - uniform environmental strategy?', or `Based on their characteristics, can different issues, different regions and different applications have unique environmental strategies?' Based on this premise, the next stage of management may be identified as risk based sustainable environmental management. The goal of this style will be the risk based, long term, harmonious management of economic resources and environmental preservation for health, safety and prosperity of sustainable populations. When evaluation of risk or risk based ranking of management alternatives enter the picture as part of the overall puzzle, then social policy, ethics and health issues assume a very important role in the management strategy. Economic incentives and environmental constraints have to be considered harmoniously, the main emphasis being placed on protection and preservation of human health and the long term sustaining of populations.

This volume is meant to provide the practitioner with information on the natural mixing processes occurring in aquifers as well as to describe basic strategies that can be implemented to enhance mixing in particular cases. For example, when it comes to mixing miscible liquids, one can speed up mixing in the formation by manipulating the flow such as through the use of recirculation wells. Furthermore, much of the mixing can be achieved partially within recirculation wells themselves, where contaminated water is admixed with additives, volatile products may be removed through a vapor mass exchanger, etc. Thus, adding mixing wells can significantly increase the performance of the delivery and mixing system and speed up the process of remediation.

Mathematical models are powerful tools used in the prediction of pollutant movement. This book discusses the Finite Element Method (FEM) and Boundary Element Method (BEM), and takes a look at the advantages of these methods in groundwater hydrology. The combination of the BEM and the random-walk particle tracking method is also presented. The book includes computer programs, source code, and examples developed on the basis of the theoretical backgrounds of these methods. These Visual C++ programs are compatible with the Windows platform.

Prepared by the Groundwater Risk Assessment Task Committee for the Water Pollution Management Committee of the Environmental Engineering Division of ASCE. ThisØreport discusses the control of contaminated groundwater and the use of risk assessment to mitigate this contamination. The report explores such issues asØdefining the level of contamination,Ødetermining which substances are contaminants, andØdeciding the level of restoration needed. These and other issues are discussed within the framework of risk assessment and risk management. Critical components of risk assessment and risk management are described, as are their strengths and weaknesses.

Reducing cost is a critical challenge facing environmental remediation today. One of the most effective ways of reducing costs is to improve decision-making. This can range from choosing more cost- effective remediation alternatives (for example, determining whether a groundwater contamination plume should be remediated or not) to improving data collection (for example, determining when data collection should stoop). Uncertainty in site conditions presents a major challenge for effective decision-making. We present a framework for increasing the effectiveness of remedial design decision-making at groundwater contamination sites where there is uncertainty in many parameters that affect remediation design. The objective is to provide an easy-to-use economic framework for making remediation decisions. The presented framework is used to 1) select the best remedial design from a suite of possible ones, 2) estimate if additional data collection is cost-effective, and 3) determine the most important parameters to be sampled. The framework is developed by combining elements from Latin-Hypercube simulation of contaminant transport, economic risk-cost-benefit analysis, and Regional Sensitivity Analysis (RSA).