Permitting Bridge Repair/Replacement Projects with Respect to Standards Protecting Fish from Underwater Sound Injuries

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1 Permitting Bridge Repair/Replacement Projects with Respect to Standards Protecting Fish from Underwater Sound Injuries James Reyff Illingworth & Rodkin, Inc TRB ADC40 Summer Meeting July 2008 Key West FL

2 Structure of this talk Pile Driving Noise Impacts to Fish Estimating Noise from Construction Minimization Measures Impact Zone Example with Conditions of Approval Fish exclusion zone Delay construction when limit exceeded

3 Construction Impacts Impact pile driving generates high underwater noise impacts that can be lethal to fish Vibratory pile installation produces lower amplitude noise, but is continuous Interim guidance on impacts to fish have been developed by the Fisheries Hydroacoustic Workgroup

4 New Bridge Construction

5 New Bridge Construction

6 In-Water Vibratory Pile Driving

7 Impacts to Fish: Known Science The Effects of Sound on Fish (Popper & Hastings 2005) Interim Criteria for Injury of Fish Exposed to Pile Driving Operations: A White Paper (Popper et al, 2006) Update on Recommendation for Revised Interim Sound Exposure Criteria for Fish during Pile Driving Activities (Popper, Hastings and Carlson 2007)

8 Impacts to Fish: Interim Thresholds Peak Pressure Criteria 206 db Peak for any single pile strike or pulse Accumulated SEL Criteria 187 db for any fish > 2 grams 183 db for smaller fish

9 NOAA Criteria Effect Metric Fish mass Threshold Onset of physical injury Adverse behavioral effects Peak pressure N/A 206 db (re: 1 µpa) Accumulated Sound? 2 g 187 db (re: 1µPa 2 sec) Exposure Level (SEL) < 2 g 183 db (re: 1µPa 2 sec) Root Mean Square Pressure (RMS) N/A 150 db (re: 1 µpa)

10 Peak Pressure Sound Pressure ( µpa ) 3.0E E E E+10 Expressed as -Pascal (N/m 2 ) -PSI -db - using reference of 1uPa Peak Maximum of the absolute sound pressure -3.0E Time ( sec )

11 SEL Sound Exposure Level for 185 a Single Pile Strike Sound Energy Accumulation (db re 1µPa^2 sec) SEL sum of the cumulative pressure squared over the time of the event Time ( sec )

12 Accumulated SEL Sum of the cumulative pressure squared over the time of the entire pile driving event (avoiding contribution from background) Alternatively, SELacc = SELstrk + 10 * Log(number of daily pile strikes) These are total daily pile strikes

13 Calculated sound effects on fish are a function of Source level Rate of sound propagation Number of piles strikes or duration of pile driving Presence of fish

14 Stationary Fish NOAA Worksheet #1 Fill in green cells: estimated sound levels and distances at which they were measured, estimated number of pile strikes, level for effective quiet and transmision loss constant. Acoustic Metric Peak SEL RMS Effective Quiet Measured single strike level (db) Distance (m) Estimated number of strikes 1000 Cumulative SEL at measured distance 210 Distance (m) to threshold Auditory tissue injury Behavior Peak Cumulative SEL db** RMS db Fish? 2 g Fish < 2 g db Transmission loss constant (15 if unknown) ** This calculation assumes that single strike SELs < 150 db do not accumulate to cause injury (Effective Quiet). Credit David Woodbury, NMFS Southwest Division

15 NOAA Worksheet #2 Moving Fish Input Enter Data Strike interval (seconds between hammer strikes) 1.5 Fish speed (m/s) 0.1 Number of strikes 2000 Closest distance fish passes pile (m) 5 Estimated single strike peak SPL (db re 1uPa) 205 Threshold for peak pressure 206 Estimated single strike SEL (db re 1 upa 2 s) (or peak SPL minus 25) 180 Threshold for accumulated SEL 187 Estimated single strike RMS SPL (db re 1uPa) (or peak SPL minus 15) 195 Behavioral Threshold for RMS (db) 150 Distance(m) from pile measurements were taken 10 Transmission loss constant (default = 15) 15 Effective Quiet (db) 150 Output Results Peak SPL at closest distance to pile 210 Distance (m) to 206 db peak isobar 9 Accumulated SEL for given number of strikes 206 RMS at closest distance to pile 200 Distance (m) to 150 db RMS isobar 10000

16 NOAA Worksheet #2 Moving Fish Input Enter Data Strike interval (seconds between hammer strikes) 1.5 Fish speed (m/s) 0.1 Number of strikes 2000 Closest distance fish passes pile (m) 5 Estimated single strike peak SPL (db re 1uPa) 205 Threshold for peak pressure 206 Estimated single strike SEL (db re 1 upa 2 s) (or peak SPL minus 25) 180 Threshold for accumulated SEL 187 Estimated single strike RMS SPL (db re 1uPa) (or peak SPL minus 15) 195 Behavioral Threshold for RMS (db) 150 Distance(m) from pile measurements were taken 10 Transmission loss constant (default = 15) 15 Effective Quiet (db) 150 Output Results Peak SPL at closest distance to pile 210 Distance (m) to 206 db peak isobar 9 Accumulated SEL for given number of strikes 206 RMS at closest distance to pile 200 Distance (m) to 150 db RMS isobar Peak SPL Strikes Accumulated SEL Credit David Woodbury, NMFS Southwest Division Strikes

17 Sound Source Levels Compendium Complicated to Modeling Problem

22 Sound Propagation Complicated Well bounded environment Extended source Groundborne sound Sound propagating through saturated soils Use of 15 Log drop off (4.5 db/dd) Measured drop off rates 10 Log to 30 Log considerable range

23 Example for Deep Water Sound Pressure (db re 1 µpa) Large Diameter Piles R 2 = R 2 = R 2 = Distance (meters) Meas. Peak Peak = Log(R/10) Meas. RMS RMS = Log(R/10) Meas SEL SEL = Log(R/10) Log. (Meas SEL) Log (Meas Peak)

24 PEAK Sound Level Drop Off 205 Sound Pressure Level - RMS db Part 1 Part 2 Part 3 15Log part 1 15Log Part 2 15 Log Part 3 14 db 16 db 12 db Distance (meters)

25 190 Propagation rate affects distance of take substantially Accumulated 187 db Accumulated 187 db meters SEL Per Strike Log 16 Log 17 Log 150 SEL at 10m = 180 db 500 Pile strikes Distance

26 Duration/Exposure Number of Pile Strikes Good questions for Engineers because they usually don t know during design Estimated based on pile length Number of sections Estimated based on hammer Size Estimated based on soil resistance

27 Minimization Measures Air bubble curtains Confined / unconfined Dewatered cofferdams Avoid in water driving Move footings out of water Construction windows Avoid times when species are present

28 Impact Zone Distance / radius of area >206 db Peak Distance / radius of area >187 db SELacc 183 db SELacc for very small fish What does this mean???

29 Example Mad River Project U.S. 101 Eureka, CA

30 Example Mad River Project

31 Replace Bridge Over Mad River Two parallel bridges constructed in separate years Each bridge has two piers near the wetted channel One additional pier/bent 130 feet or further from channel Short pile driving window Each pier consist of two 7-ft dia piles 150 ft long 3 to 4 sections In dewatered cofferdam (no direct contact with water)

32 Methodology Sound predictions made based on most similar project Source levels Propagation rates Identified duration with little help from engineers based on experience Presence of fish confirmed

33 Impacts No area >206 db Peak Assume two pile sections driven each day for 1,800 strikes = ~150 meters to Accumulated 187 db SEL 300 m of river would have fish potentially impacted (a take) Estimated to affect X fish

35 150m Impact Area West

36 Imposed Agency Conditions Develop a fish exclusion zone for 300m of river 6 to 10 days of pile driving required Continuous sound monitoring to precisely define the zone Terminate construction if levels accumulate to 187 db SEL at fish exclusion zone boundaries Requires live monitoring results Noise monitor serves as the cop that can stop construction and cost $$$$$$$$$ Live fish in cage study

37 That s it

NEW METHODS IN IMPACT PILE DRIVING NOISE ATTENUATION

NEW METHODS IN IMPACT PILE DRIVING NOISE ATTENUATION Per G. Reinhall a, John T. Dardis II a a University of Washington, Mechanical Engineering, Stevens Way, Box 352600, Seattle, WA 98195, United States