Ground Water Pollution Control

L.W. Canter

• Publisher: CRC Press
• Year: 2020
• Print ISBN: 9780873710145
• eBook ISBN: 9781000157420
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Environmental Management
• Index: Technology & Engineering

Covers thoroughly technologies for ground water pollution control in part one and deals in depth with aquifer restoration decision-making in part two. Part three gives an extensive range of case studies and detailed references.

CHAPTER 1

Introduction

Pollution of ground water can result from many activities, including leaching from municipal and chemical landfills and abandoned dump sites, accidental spills of chemicals or waste materials, improper underground injection of liquid wastes, and placement of septic tank systems in hydrologically and geologically unsuitable locations. In recent years incidents of aquifer pollution from man’s waste disposal activities have been discovered with increasing regularity. Concurrently, demands for ground water usage have been increasing due to population growth and diminishing opportunities to economically develop surface water supplies. Until recently the general viewpoint held by many ground water professionals and policy-makers was that once an aquifer had become polluted its water usage must be curtailed or possibly eliminated. However, this viewpoint is changing as a result of increasing needs for ground water utilization and the development of appropriate methodologies for ground water pollution control (aquifer cleanup). The focus on methodologies has been heightened by current hazardous waste site cleanup efforts funded by “Superfund.”

CLASSIFICATION OF METHODOLOGIES

Table 1.1 lists methodologies for ground water quality protection and treatment organized according to whether the pollution problem is acute or chronic. Acute pollution may occur from inadvertent spills of chemicals or releases of undesirable materials and chemicals during a transportation accident. Acute pollution events are unplanned and are characterized by their emergency nature. Chronic aquifer pollution may occur from numerous point and area sources and may involve traditional pollutants such as nitrates and bacteria, or unique pollutants such as gasoline, metals, and synthetic organic chemicals.

Table 1.1 Methodologies for Ground Water Quality Protection and Treatment

Pollution Problem	Goal	Methodologies
Acute	Abatement	1. In situ chemical fixation. 2. Excavation of contaminated soil with subsequent backfilling with “clean” soil.
	Restoration	1. Removal wells, treatment of contaminated ground water, and recharge. 2. Removal wells, treatment of contaminated ground water, and discharge to surface drainage. 3. Removal wells and discharge to surface drainage.
Chronic	Abatement	1. In situ chemical fixation. 2. Excavation of contaminated soil with subsequent backfilling with “clean” soil. 3. Interceptor trenches to collect polluted water as it moves laterally away from site. 4. Surface capping with impermeable material to inhibit infiltration of leachate-producing precipitation. 5. Subsurface barriers of impermeable materials to restrict hydraulic flow from sources. 6. Modify pumping patterns at existing wells. 7. Inject fresh water in a series of wells placed around source or contaminant plume to develop pressure ridge to restrict movement of pollutants.
Chronic	Restoration	1. Removal wells, treatment of contaminated ground water, and recharge. 2. Removal wells, treatment of contaminated ground water, and discharge to surface drainage. 3. Removal wells and discharge to surface drainage. 4. In situ chemical treatment. 5. In situ biological treatment.

Methodologies for ground water pollution control can also be considered in terms of the goals of abatement and restoration. Abatement means “to put an end to”; therefore, abatement as a goal refers to the application of methodologies which will aid in preventing pollutant movement into ground water, or preventing contaminated plume movement into usable aquifer zones. The latter example of abatement is also called plume management. Aquifer restoration as a goal refers to the restoration of water quality to its normal quality, usually by removing both the source of pollution and renovating the polluted ground water. If the pollution source has already been dissipated by time, restoration may only involve renovation of the polluted ground water.

It should be noted that a given aquifer cleanup project may involve usage of several methodologies in combination. For example, for an acute problem, excavation and backfilling may be used in conjunction with removal wells, treatment of contaminated ground water, and discharge to surface drainage. A chronic pollution cleanup project may include surface capping, subsurface barriers, and in situ chemical treatment.

OVERVIEW STUDIES

In 1977, Lindorff and Cartwright surveyed the nation for case histories of aquifer clean-up. Information on 116 cases of aquifer pollution was summarized, with most of the pollution either caused by industrial wastes or by leaching from municipal landfills. Table 1.2 summarizes the cleanup methodologies used in 32 of the cases. (Lindorff and Cartwright, 1977). Removal wells are best applied when the pollution has not traveled far from the source, and they have most ofte...

Table of contents

• Cover
• Title Page
• Copyright Page
• Preface
• Dedication
• Table of Contents
• List of Figures
• List of Tables
• 1 Introduction
• Technologies for Ground Water Pollution Control
• Decision-Making in Aquifer Restoration Projects
• Case Studies and Applications of Ground Water Pollution Control
• Index