Preface SOIL VAPOR EXTRACTION-INTRODUCTION AND BACKGROUND Historical Background and Literature Review SOIL VAPOR EXTRACTION-A PHASED APPROACH Introduction Preliminary Assessment of Vapor Stripping GAS FLOW IN SOIL VAPOR EXTRACTION Introduction Darcy's Law in Soil Vapor Extraction Calculation of Soil Gas Flow Fields Conclusions EQUILIBRIA AND MASS TRANSPORT OF VOCs IN SOILS Introduction Equilibrium Mass Transport Kinetics SOIL VAPOR EXTRACTION MODELING-ANALYSIS Introduction-Why Does One Model? SVE by Means of a Single Vertical Well, Linear Adsorption Isotherm, Local Equilibrium and Constant Isotropic Permeability SVE with a Single Buried Horizontal Slotted Pipe, Linear Adsorption Isotherm, Local Equilibrium, and Constant Isotropic Permeability One-Dimensional Models with Constant Isotropic Permeability, Local Equilibrium, and a Linear Adsorption Isotherm More Complex Local Equilibrium SVE Models Diffusion/Desorption Kinetic Limitations A Lumped Parameter Approach The Steady-State Approximation Diffusion-Limited SVE of NAPL SVE of NAPL Mixtures Obeying Raoult's Law Removal of Floating NAPL Effects of Variable Airflow Rates in Diffusion-Limited SVE Operation Distributed Diffusion Models for the SVE of NAPL and Dissolved VOC Conclusions SOIL VAPOR EXTRACTION MODELING-RESULTS Introduction Cleanup Time Distributions for Statistically Equivalent Variable Permeabilities Random Permeability Functions Model Results, Permeabilities Soil Vapor Extraction Modeling with Random Permeabilities Conclusions Regarding Random Permeabilities Vapor Stripping of NAPL VOCs in Mixtures Obeying Raoult's Law Diffusion/Desorption Kinetics: The Lumped Parameter Approximation Diffusion-Advection from an Underlying Floating NAPL Pool Effects of Variable Airflow Rates in Diffusion-Limited SVE Operation Variable Airflow Rate Results Distributed Diffusion Model Results Effects of VOC Concentration Distribution Diffusion/Desorption Kinetics Modeling Conclusions SPARGING: A NEW TECHNOLOGY FOR THE REMEDIATION OF AQUIFERS CONTAMINATED WITH VOLATILE ORGANIC COMPOUNDS Introduction Sparging with Air Injection Wells-A Design Primer System Description Effects of Air Sparging Limitations to Air Sparging Air Sparging System Design Outstanding Issues Concerning Air Sparging Conclusion A Screening Model for Sparging Recent and Current Activity in Sparging SPARGING: THEORY AND MATHEMATICAL MODELS Introduction Theory of Sparging and Model Development Conclusions BIOVENTING Introduction The Biodegradation Processes Bioventing Operation and Design Monitoring in situ Bioremediation A Model for Bioventing Description of the Simplified Model Model Results and Discussion Conclusions IMPLEMENTATION OF SOIL VAPOR EXTRACTION: REGULATORY AND OTHER ISSUES Introduction Site Characterization Pitfalls to Implementation Regulatory Issues in the United States SOIL VAPOR EXTRACTION COSTS Introduction Considerations in SVE Cost Estimating Review of SVE Cost Estimates Effects of Equilibrium on Remediation Costs Conclusions Based upon Nonequilibrium Effects Index.