Final Technical Guidance for Assessment and Mitigation of the Hydroacoustic Effects of Pile Driving on Fish Prepared for: California Department of Transportation 1120 N Street Sacramento, CA 94274 Contact: Jim Andrews Prepared by: ICF Jones & Stokes 630 K Street, Suite 400 Sacramento, CA 95818 Contacts: Rick Oestman, Dave Buehler And: Illingworth and Rodkin, Inc 505 Petaluma Blvd. South Petaluma, CA 94952 Contacts: James Reyff, Rich Rodkin February 2009 Table of Contents Chapter 1. Introduction and Background ................................................... 1-1 Chapter 2. Fundamentals of Hydroacoustics .............................................. 2-1 2.1 Fundamental Principles of Hydroacoustics................................................................................... 2-1 2.2 Underwater Sound Propagation .................................................................................................... 2-9 2.3 Measurement of Underwater Sound ........................................................................................... 2-13 2.4 Examples of Underwater Pile Driving Sound Levels ................................................................. 2-15 2.5 Common Underwater Sound Reduction Measures ..................................................................... 2-17 2.5.1 Bubble Curtains ............................................................................................................. 2-18 2.5.2 Coffer Dams ................................................................................................................... 2-25 2.5.3 Vibratory Hammers ....................................................................................................... 2-25 2.5.4 Other Sound Reduction Systems ................................................................................... 2-25 2.6 References ................................................................................................................................... 2-26 Chapter 3. Fundamentals of Hydroacoustic Impacts on Fish ..................... 3-1 3.1 Introduction ................................................................................................................................... 3-1 3.2 Types of Fishes ............................................................................................................................. 3-1 3.3 Fish Hearing .................................................................................................................................. 3-2 3.4 Potential Effects of Pile Driving Noise on Hearing in Fish .......................................................... 3-3 3.5 Potential Effects of Pile Driving Noise on Fish Anatomy and Physiology .................................. 3-4 3.6 Life History Considerations .......................................................................................................... 3-5 3.7 Behavioral Effects ......................................................................................................................... 3-5 3.8 Environmental Factors to Consider in Analysis ........................................................................... 3-6 3.9 References ..................................................................................................................................... 3-6 Chapter 4 . Framework and Process for Environmental Analysis of Pile Driving Impacts on Fishery Resources for Project Planning, Development, and Implementation .................................................................................. 4-1 4.1 Introduction ................................................................................................................................... 4-1 4.2 Permits and Regulatory Requirements for In-Water Pile Driving Activities ............................... 4-1 4.3 Information Needed to Evaluate Impacts ...................................................................................... 4-1 4.4 Avoidance and Minimization Measures, Best Management Practices, and Performance Standards ....................................................................................................................................... 4-8 4.4.1 Avoidance and Minimization Measures .......................................................................... 4-8 4.4.1.1 Project Timing .................................................................................................... 4-8 4.4.1.2 Pile Placement .................................................................................................... 4-8 4.4.1.3 Pile Driving Equipment ...................................................................................... 4-9 4.4.1.4 Pile Type ............................................................................................................. 4-9 4.4.1.5 Pile Size .............................................................................................................. 4-9 4.4.2 Best Management Practices ............................................................................................. 4-9 4.4.2.1 Air Bubble Curtains .......................................................................................... 4-10 4.4.2.2 Cofferdams ....................................................................................................... 4-10 4.4.2.3 Isolation Casings ............................................................................................... 4-10 4.4.2.4 Cushion Blocks ................................................................................................. 4-11 4.4.3 Performance Standards .................................................................................................. 4-11 4.5 Considerations for Assessing Impacts ........................................................................................ 4-12 4.5.1 Habitat ............................................................................................................................ 4-12 Technical Guidance for Assessment and Final Mitigation of the Hydroacoustic Effects of Pile Driving on Fish i February 2009 4.5.2 Sound Sensitivity ........................................................................................................... 4-12 4.5.3 Behavior and Life History ............................................................................................. 4-12 4.5.4 Protected Status .............................................................................................................. 4-13 4.6 Impact Analysis .......................................................................................................................... 4-13 4.6.1 Determining the Ambient Noise Levels ........................................................................ 4-14 4.6.2 Determining the Expected Pile Driving Sound Pressure Levels .................................... 4-15 4.6.2.1 Type of Pile Driver ........................................................................................... 4-16 4.6.2.2 Type and Size of Piles ...................................................................................... 4-16 4.6.2.3 Type of Attenuation .......................................................................................... 4-16 4.6.3 Calculating the Underwater Sound Attenuation ............................................................ 4-16 4.6.3.1 Empirical Sound Attenuation Data ................................................................... 4-18 4.6.4 Interim Injury Thresholds .............................................................................................. 4-20 4.6.4.1 Background ....................................................................................................... 4-20 4.6.4.2 Update on Recommendations for Revised Interim Criteria for Pile Driving (Carlson et al. 2007) ............................................................................ 4-20 4.6.4.3 Agreement in Principal for Interim Criteria for Injury to Fish from Pile Driving Activities ............................................................................................. 4-21 4.6.4.4 Criteria for Injury to Fish from Vibratory Pile Driving .................................... 4-22 4.6.5 Behavioral Thresholds ................................................................................................... 4-22 4.6.6 Determining the Impact Zones ....................................................................................... 4-22 4.6.6.1 Underwater Noise Prediction Methods and Tools ............................................ 4-23 4.6.6.2 Acoustic Impact Area for In-Water Pile Driving .............................................. 4-24 4.6.6.3 Acoustic Impact Area for Near-Water Pile Driving ......................................... 4-25 4.6.6.4 Example Calculations ....................................................................................... 4-26 4.6.6.5 Application of the Practical Spreading Model and NOAA Fisheries Calculation Spreadsheet .................................................................................... 4-29 4.6.7 Assessing Potential Impacts on Fish from Pile Driving Noise ...................................... 4-31 4.6.7.1 Impact Assessment When Construction Occurs during Migration Periods ...... 4-31 4.6.7.2 Impact Assessment When Construction Occurs during Non-Migration Periods .............................................................................................................. 4-34 4.7 Lessons Learned