Best Practices for Addressing Induced Seismicity Associated With Enhanced Geothermal Systems (EGS) By Ernie Majer, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 James Nelson, Wilson Ihrig & Associates, Emeryville, CA 94608 Ann Robertson-Tait, GeothermEx, Inc., Richmond, CA 94806 Jean Savy, Savy Risk Consulting, Oakland, CA 94610 Ivan Wong, URS Corporation, Oakland, CA 94612 TABLE OF CONTENTS Abbreviations .............................................................................................................................................. vi Glossary .................................................................................................................................................... viii Units........................................................................................................................................................... xiv Foreword .................................................................................................................................................... xv Section 1 ONE Step 1: Preliminary Screening Evaluation .................................................................... 1-1 1.1 Purpose ..................................................................................................... 1-1 1.2 Guiding Principles for Site Screening...................................................... 1-1 1.3 Evaluate Risks With Simple Bounding Methods ..................................... 1-2 1.3.1 Local, State, and Federal Governments’ Acceptance Criteria ......................................................................................... 1-3 1.3.2 Impact On Local Community ...................................................... 1-3 1.3.3 Natural Seismicity and Associated Long-Term Seismic Risk .............................................................................................. 1-4 1.3.4 Magnitude and Location of Worst Case Induced Earthquake and Associated Risk .................................................. 1-4 1.3.5 Assessing the Overall Risk of the Planned EGS .......................... 1-5 1.3.6 Identify Main Possible Risk-Associated Reasons for Not Completing a Project .................................................................... 1-5 1.4 EGS Project Benefits ............................................................................... 1-6 1.5 Documentation for Initial Project Phase Decision Making ..................... 1-6 1.5.1 Full Technical Documentation ..................................................... 1-6 1.5.2 Summary Evaluation of the Risk ................................................. 1-6 1.6 Case Studies ............................................................................................. 1-7 Section 2 TWO Step 2: Outreach and Communications ........................................................................ 2-1 2.1 Purpose ..................................................................................................... 2-1 2.2 Main Elements ......................................................................................... 2-1 2.3 Examples .................................................................................................. 2-2 2.3.1 Other Industrial Projects .............................................................. 2-2 2.3.2 EGS Projects ................................................................................ 2-6 2.3.3 Project Near a Community........................................................... 2-6 2.3.4 Project Distant From a Community ............................................. 2-8 2.4 Recommended Approach ......................................................................... 2-9 2.5 Summary ................................................................................................ 2-11 Section 3 THREE Step 3: Criteria for Damage, Vibration, and Noise ....................................................... 3-1 3.1 Purpose ..................................................................................................... 3-1 3.2 Building Damage Criteria ........................................................................ 3-2 3.2.1 Threshold Cracking ...................................................................... 3-3 3.2.2 Minor and Major Damage .......................................................... 3-10 3.3 Damage Criteria for Civil Structures ..................................................... 3-10 C:\DOCUMENTS AND SETTINGS\DSHAWKES\DESKTOP\PUBLICATIONS\DOCUMENTS WAITING FOR LBNL NUMBERS\2013\OCTNOVDEC2013\MAJER-BEST PRACTICES EGS INDUCED SEISM TABLE OF CONTENTS 3.4 Damage Criteria for Buried Structures .................................................. 3-11 3.4.1 Wells .......................................................................................... 3-11 3.4.2 Pipelines ..................................................................................... 3-11 3.4.3 Basement Walls ......................................................................... 3-12 3.4.4 Tunnels ....................................................................................... 3-12 3.5 Landslide and Rockslide ........................................................................ 3-13 3.6 Human Response ................................................................................... 3-13 3.6.1 Third Octave Filters ................................................................... 3-13 3.6.2 Vibration .................................................................................... 3-14 3.6.3 Ground-Borne Noise .................................................................. 3-25 3.7 Laboratory and Manufacturing Facilities ............................................... 3-27 3.7.1 Criteria ....................................................................................... 3-27 3.8 Summary ................................................................................................ 3-30 3.9 Suggested Reading ................................................................................. 3-31 Section 4 FOUR Step 4: Collection of Seismicity Data ............................................................................ 4-1 4.1 Purpose ..................................................................................................... 4-1 4.2 Gathering Data to Establish Background/Historical Seismicity Levels: Regional ...................................................................................... 4-1 4.2.1 Possible Sources of Background Data ......................................... 4-2 4.2.2 Data Requirements ....................................................................... 4-2 4.3 Local Seismic Monitoring ........................................................................ 4-4 4.3.1 Basic Requirements ..................................................................... 4-4 4.3.2 Instrumentation Needs and Data Coverage .................................. 4-5 4.3.3 Instrumentation and Deployment ................................................. 4-6 4.3.4 Data Archiving and Processing Requirements ............................ 4-9 4.4 Summary ................................................................................................ 4-11 4.5 Suggested Reading ................................................................................. 4-11 Section 5 FIVE Step 5: Hazard Evaluation of Natural and Induced Seismic Events ........................... 5-1 5.1 Purpose ..................................................................................................... 5-1 5.2 Overview of Approach ............................................................................. 5-2 5.2.1 Estimate the Baseline Hazard From Natural Seismicity .............. 5-2 5.2.2 Estimate the Hazard From Induced Seismicity ............................ 5-2 5.3 PSHA Methodology and Computer Programs ......................................... 5-3 5.3.1 Evaluate Historical Seismicity ..................................................... 5-3 5.3.2 Characterize Seismic Sources ...................................................... 5-5 5.3.3 Areal Sources ............................................................................... 5-8 5.3.4 Characterize Site Conditions ........................................................ 5-8 5.3.5 Select Ground Motion Prediction Models ................................... 5-9 5.3.6 PSHA Products ............................................................................ 5-9 5.4 Additional Steps In Characterizing EGS for PSHA .............................. 5-10 5.4.1 Characterize Local and Regional Stress Field ........................... 5-11 5.4.2 Develop 3D Geologic Model ..................................................... 5-11 5.4.3 Review of Relevant EGS Case Histories ................................... 5-11 C:\DOCUMENTS AND SETTINGS\DSHAWKES\DESKTOP\PUBLICATIONS\DOCUMENTS WAITING FOR LBNL NUMBERS\2013\OCTNOVDEC2013\MAJER-BEST PRACTICES EGS INDUCED SEISM TABLE OF CONTENTS 5.4.4 Develop Induced Seismicity Model ........................................... 5-11 5.4.5 Select Ground Motion Prediction Models for Induced Seismicity ................................................................................... 5-13 5.4.6 Products...................................................................................... 5-13 5.5 Summary ................................................................................................ 5-13 5.6 Suggested Reading ................................................................................