GROUND WATER VULNERABILITY ASSESSMENT -- Copyright -- Preface -- Contents -- Executive Summary -- INTRODUCTION -- The Vulnerability Assessment Process -- MANAGEMENT -- APPROACHES TO VULNERABILITY ASSESSMENT -- Uncertainty in Vulnerability Assessment -- Testing and Evaluation of Vulnerability Assessments -- Computing Environments for Vulnerability Assessments -- DATA AND DATABASES -- CASE STUDIES -- RESEARCH RECOMMENDATIONS -- REFERENCE -- 1 Introduction -- PROTECTING GROUND WATER FROM FUTURE CONTAMINATION -- Ground Water Vulnerability to Contamination -- ASSESSING GROUND WATER VULNERABILITY -- Uncertainty in the Assessment Process -- Elements of Vulnerability Assessment -- Reference Location -- Specific and Intrinsic Vulnerability -- Contaminant Pathways -- Spatial Scales -- THE VULNERABILITY ASSESSMENT PROCESS -- Case Studies -- REFERENCES -- 2 Considerations in the Selection and Use of Vulnerability Assessments -- INTRODUCTION -- EXISTING AND POTENTIAL USES FOR VULNERABILITY ASSESSMENTS -- Policy Analysis and Development -- Program Management -- Land Use Decisions -- Zoning and Screening -- Conditioning, Mitigating, and Compliance Monitoring -- Technical Assistance -- General Education and Awareness -- FACTORS AFFECTING SELECTION AND USE OF VULNERABILITY ASSESSMENTS -- Technical Considerations -- Type and Form of Output -- Size and Characteristics of Assessment Area -- Availability of Data -- Uncertainty of Results and Impact on Use -- Institutional Considerations -- Time Frame of a Vulnerability Assessment -- Cost and Commitment of Personnel and Physical Resources -- Coordination with Other Planning Programs and Needs -- Coordination with Other Agencies and Institutions -- SUMMARY -- 3 Approaches to Vulnerability Assessments -- INTRODUCTION -- REVIEW OF CURRENT APPROACHES -- Overlay and Index Methods -- Depth to Ground Water -- Recharge.

Properties of the Unsaturated Zone and Aquifer Material -- Discussion -- Process-Based Simulation Models -- Discussion -- Statistical Techniques for Vulnerability Assessment -- Regionalization -- Vulnerability Assessment -- UNCERTAINTY IN VULNERABILITY ASSESSMENT METHODS -- Sources of Errors -- Errors in Obtaining Data -- Errors Due to Natural Spatial and Temporal Variability -- Errors in Computerization (Digitizing) and Storage of Data -- Data Processing Errors -- Models and Conceptualizations -- Output and Visualization Errors -- Uncertainty Analyses -- Applications of FOUA to Vulnerability Assessment -- Uncertainty of Uncertainty Analyses -- TESTING AND EVALUATION OF VULNERABILITY ASSESSMENTS -- Regional-Scale Testing and Evaluation -- Limitations of Ground Water Quality Sampling -- Difficulties in Characterizing the Mobile Fraction of Contaminants -- Sampling Near the Water Table -- Purging and Pumping -- COMPUTING ENVIRONMENTS FOR VULNERABILITY ASSESSMENTS -- Building and Making Databases Available for Assessment Approaches -- Geographical Display of Assessment Results -- Analytical Functions -- SUMMARY -- REFERENCES -- 4 Data and Databases -- INTRODUCTION -- Federal Data Management Activities -- State and Local Data Management Activities -- TOPOGRAPHY -- Characteristics and Availability of Data -- Discussion -- SOILS -- Characteristics and Availability of Data -- Geographic Databases -- Attribute Databases -- Site-Specific Databases -- Discussion -- HYDROGEOLOGY -- Characteristics and Availability of Data -- Discussion -- WEATHER AND CLIMATE -- Characteristics and Availability of Data -- Discussion -- LAND USE AND LAND COVER -- Characteristics and Availability of Data -- Discussion -- MANAGEMENT FACTORS -- Characteristics and Availability of Data -- National Resources Inventory -- Agricultural Census of 1987 -- Farm and Ranch Irrigation Survey.

Pesticide Databases -- Field Level Databases -- CONCLUSION -- REFERENCES -- 5 Case Studies -- INTRODUCTION -- IOWA -- Introduction -- Defining the Question -- Mandate, Selection, and Implementation -- CAPE COD -- Introduction -- Defining the Question -- Selection and Implementation of Approaches -- Results -- FLORIDA -- Introduction -- The Hydrogeologic Setting -- Defining the Question -- Selecting an Approach -- Results -- THE SAN JOAQUIN VALLEY -- Introduction -- Hydrogeologic Setting -- Defining the Question -- Selection and Implementation of an Approach -- HAWAII -- Introduction -- Defining the Question -- Approaches -- Results -- APPLICATION OF A VULNERABILITY INDEX FOR DECISION-MAKING AT THE NATIONAL LEVEL -- Need for a Vulnerability Index -- Description of the Vulnerability Index -- Application to Program Management -- Application to Policy Analysis and Development -- SUMMARY -- REFERENCES -- 6 Conclusions and Recommendations -- MANAGEMENT IMPLICATIONS -- APPROACHES -- DATA AND DATABASES -- RESEARCH AGENDA -- Fundamental Transport and Fate Processes -- Databases -- Geoprocessing and Display -- Assessment Methods -- Appendixes -- Appendix A Sources for Digital Resource Databases -- GENERAL SOURCE INFORMATION -- Appendix B Biographical Sketches -- COMMITTEE MEMBERS -- COMMITTEE STAFF -- Appendix C Contributors to the Committee's Effort -- Index.