API 4659 : 1998

EXECUTIVE SUMMARY
CHAPTER 1: Introduction
        1.1. Background
CHAPTER 2: General Theoretical Framework
        2.1 Mathematical Definition of the Dilution
               Attenuation Factor (DAF)
        2.2 Generalized Mathematical Approach
        2.3 Model Selection Criteria
        2.4 Constant and Time-Varying Source Solutions
        2.5 Mathematical Approximations
CHAPTER 3: Submerged (Saturated Zone) Sources
        3.1 Constant Strength Sources
        3.2 DAF Formulation for Time-Varying Sources
        3.3 Alternate Well Configurations
        3.4 Numerical Methods
        3.5 Submerged Source DAF Graphs
CHAPTER 4: Vadose Zone Sources
        4.1 Introduction
        4.2 Unsaturated Zone Transport Model
        4.3 Saturated Zone Transport Models
        4.4 Horizontal Plane Source (HPS) Model
        4.5 DAF Formulation for Vadose Zone Sources
        4.6 Alternate Well Configurations
        4.7 Numerical Methods
        4.8 Vadose Zone Source Graphs
        4.9 First-Order Decay Correction Factor
CHAPTER 5: Application of the Graphical Approach
        5.1 Introduction
        5.2 Submerged Source Example
        5.2.1 Generic (Tier 1) DAF Values
        5.2.2 Refined (Tier 2) DAF Values
        5.3 Vadose Zone Sources
        5.3.1 Generic DAF Estimate (Tier 1)
        5.3.2 Analysis of Nomograph Interpretation Accuracy
CHAPTER 6: Idealized Source Depletion Models
        6.1 Introduction
        6.2 General Approach - Conceptual Model
        6.2.1 Mathematical Framework - Source Zone Mass
               Balance
        6.2.2 Mathematical Framework - Chemical Partitioning
        6.3 Constant Strength (Infinite) Sources
        6.4 Exponentially-Decaying Sources
CHAPTER 7: References
APPENDIX A: Data/Parameter Selection Guide
APPENDIX B: Comparison of Approximate and Full Solutions
               to the Groundwater Transport Problem
APPENDIX C: Assessment of the Significance of Diffusive
               Transport Relative to Infiltration on
               Groundwater Impacts
APPENDIX D: HPS Model Fortran Code
LIST OF FIGURES
LIST OF TABLES

Gives description and concise instructions on the technical basis for the Graphical Approach for Determining Site-Specific Dilution-Attentuation Factors (DAF).