United States Office of Solid Waste and Environmental Protection Emergency Response EPA-542-R-97-007 Agency (5102G) September 1997 Analysis of Selected Enhancements for Soil Vapor Extraction CONTENTS Chapter Page FOREWORD...............................................................ABS-1 EXECUTIVE SUMMARY.......................................................ES-1 1.0 INTRODUCTION........................................................1-1 1.1 BACKGROUND...................................................1-1 1.2 OBJECTIVES.....................................................1-2 1.3 APPROACH......................................................1-3 1.4 REPORT ORGANIZATION..........................................1-4 2.0 BACKGROUND: SOIL VAPOR EXTRACTION ENHANCEMENT TECHNOLOGIES.2-1 3.0 AIR SPARGING.........................................................3-1 3.1 TECHNOLOGY OVERVIEW.........................................3-1 3.2 APPLICABILITY..................................................3-2 3.3 ENGINEERING DESCRIPTION.......................................3-3 3.3.1 Air Flow Within the Subsurface..................................3-4 3.3.2 Equipment Requirements and Operational Parameters.................3-6 3.3.2.1Air Sparging Wells and Probes............................3-6 3.3.2.2Manifolds, Valves, and Instrumentation....................3-10 3.3.2.3Air Compressor or Blower...............................3-11 3.3.3 Monitoring of System Performance..............................3-13 3.4 PERFORMANCE AND COST ANALYSIS.............................3-14 3.4.1 Performance................................................3-15 3.4.1.1U.S. Department of Energy Savannah River Integrated Demonstration Site....................................3-15 3.4.1.2Toluene Remediation at a Former Industrial Facility...........3-16 3.4.1.3Electro-Voice, Inc., Demonstration Site.....................3-17 3.4.2 Cost Analysis...............................................3-18 3.4.2.1Cost for Department of Energy-Patented In Situ Bioremediation System.................................3-19 3.4.2.2Cost for Subsurface Volatilization Ventilation System.........3-20 i CONTENTS (Continued) Chapter Page 3.5 VENDORS.......................................................3-21 3.6 STRENGTHS AND LIMITATIONS...................................3-21 3.7 RECOMMENDATIONS............................................3-22 3.8 REFERENCES...................................................3-23 4.0 DUAL-PHASE EXTRACTION..............................................4-1 4.1 TECHNOLOGY OVERVIEW.........................................4-1 4.2 APPLICABILITY..................................................4-2 4.2.1 Contaminant Properties.........................................4-2 4.2.2 Contaminant Phases...........................................4-3 4.2.3 Soil Characteristics............................................4-4 4.3 ENGINEERING DESCRIPTION.......................................4-5 4.3.1 Dual-Phase Extraction System Design..............................4-5 4.3.1.1Pilot Testing..........................................4-5 4.3.1.2Extraction Well Design..................................4-6 4.3.1.3Extraction Equipment Design..............................4-7 4.3.1.4System Monitoring......................................4-9 4.3.2 Dual-Phase Extraction System Characteristics........................4-9 4.3.2.1Drop-Tube Entrainment Extraction.........................4-9 4.3.2.2Well-Screen Entrainment................................4-11 4.3.2.3Downhole-Pump Extraction..............................4-13 4.4 PERFORMANCE AND COST ANALYSIS.............................4-13 4.4.1 Performance................................................4-14 4.4.1.1Underground Storage Tank Release from a Gasoline Station in Houston, Texas...............................4-14 4.4.1.2Underground Storage Tank Release from a Former Car Rental Lot in Los Angeles, California............................4-15 4.4.1.3Release From An Electronics Manufacturing Facility In Texas....4-16 4.4.1.4Underground Storage Tank Release from a Gasoline Station in Indiana......................................4-17 4.4.1.5Release from a Gasoline Underground Storage Tank for a Vehicle Fueling Station at a Hospital in Madison, Wisconsin.....4-18 ii CONTENTS (Continued) Chapter Page 4.4.2 Cost Analysis...............................................4-19 4.5 VENDORS.......................................................4-19 4.6 STRENGTHS AND LIMITATIONS...................................4-19 4.7 RECOMMENDATIONS............................................4-20 4.8 REFERENCES...................................................4-21 5.0 DIRECTIONAL DRILLING................................................5-1 5.1 TECHNOLOGY OVERVIEW.........................................5-1 5.2 APPLICABILITY..................................................5-3 5.2.1 Geologic Conditions...........................................5-4 5.2.2 Distances Achieved............................................5-4 5.3 ENGINEERING DESCRIPTION.......................................5-5 5.3.1 Drill Rigs...................................................5-5 5.3.2 Drilling Assembly.............................................5-6 5.3.2.1Tri-Cone Type Drilling Tools..............................5-7 5.3.2.2Hydraulically Assisted, Jet-Style Drilling Tools................5-7 5.3.2.3Compaction Tools......................................5-7 5.3.3 Drilling Fluids................................................5-7 5.3.4 Guidance Systems.............................................5-8 5.3.5 Directionally Drilled Well Installation..............................5-9 5.3.5.1Well Materials.........................................5-9 5.3.5.2Well Screens..........................................5-9 5.3.5.3Well Casings.........................................5-10 5.3.5.4Well Installation......................................5-10 5.3.6 Design Considerations.........................................5-10 5.3.6.1Radius of Curvature....................................5-11 5.3.6.2Air Flow Patterns......................................5-11 5.3.7 Common Problems...........................................5-12 5.4 PERFORMANCE AND COST ANALYSIS.............................5-12 5.4.1 Performance................................................5-13 iii CONTENTS (Continued) Chapter Page 5.4.1.1U.S. Department of Energy Savannah River Site Integrated Demonstration Site............................5-13 5.4.1.2Alberta Gas Plant.....................................5-14 5.4.1.3Hastings East Industrial Park.............................5-15 5.4.1.4John F. Kennedy Airport................................5-17 5.4.2 Cost Analysis...............................................5-20 5.5 VENDORS.......................................................5-21 5.6 STRENGTHS AND LIMITATIONS...................................5-21 5.7 RECOMMENDATIONS............................................5-23 5.8 REFERENCES...................................................5-23 5.8.1 Cited References.............................................5-23 5.8.2 Professional Contacts.........................................5-26 6.0 PNEUMATIC AND HYDRAULIC FRACTURING..............................6-1 6.1 TECHNOLOGY OVERVIEW.........................................6-1 6.2 APPLICABILITY..................................................6-2 6.2.1 Geologic Conditions...........................................6-3 6.2.2 Contaminants................................................6-4 6.2.3 Technologies Enhanced by Fracturing..............................6-5 6.3 ENGINEERING DESCRIPTION.......................................6-5 6.3.1 Injection Media...............................................6-6 6.3.2 Fracturing Equipment..........................................6-7 6.3.3 Injection Pressure and Rate......................................6-8 6.3.4 Fracture Size and Shape........................................6-8 6.3.5 Site Conditions.............................................. 6-10 6.3.6 Monitoring the Formation of Fractures............................6-10 6.3.7 Well Completion.............................................6-11 6.3.8 Pneumatic Fracturing.........................................6-11 6.3.9 Hydraulic Fracturing..........................................6-12 6.4 PERFORMANCE AND COST ANALYSIS.............................6-13 6.4.1 Performance................................................6-13 6.4.1.1Pneumatic Fracturing Enhancement of SVE and Hot Gas Injection in Shale...............................6-14 iv CONTENTS (Continued) Chapter Page 6.4.1.2Pneumatic Fracturing Enhancement of SVE in Clay............6-15 6.4.1.3Hydraulic Fracturing Enhancement of DPE in Clayey Silts.......6-16 6.4.1.4Pilot-Scale Testing of Hydraulic Fracturing at Linemaster Switch Superfund Site.........................6-17 6.4.2 Cost Analysis...............................................6-18 6.4.2.1Costs of Pneumatic Fracturing............................6-18 6.4.2.2Costs of Hydraulic Fracturing............................6-20 6.5 VENDORS.......................................................6-21 6.6 STRENGTHS AND LIMITATIONS...................................6-21 6.7 RECOMMENDATIONS............................................6-22 6.8 REFERENCES...................................................6-23 6.8.1 Cited References.............................................6-23 6.8.2 Professional Contacts.........................................6-25 7.0 THERMAL ENHANCEMENT..............................................7-1