In-water Pile Driving Criteria in wetted channel
Impact pile driving that exceeds the Interim Pile Driving Criteria (June 2008) listed below (or current Pile Driving Criteria when 2008 criteria are updated) is excluded for inclusion:
Peak pressure = 206 dBpeak
Accumulated sound exposure levels = 183 dB cSEL
Accumulated sound exposure levels for fish over 2g = 187 dB cSEL
The 183 dB cSEL level will be used unless, through the variance process defined below, salmonids under 2 grams are determined to be absent. The number of piles, type/size of the piles, estimated sound levels caused by the driving, how many piles will be driven each day, and any other relevant details on the nature of the pile driving activity must be included in the project application. See Technical Guidance for the Assessment of Hydroacoustic Effects of Pile Driving on Fish (2020) Caltrans Hydroacoustic Manual for more information on assessment techniques https://dot.ca.gov/-/media/dot media/programs/environmental-analysis/documents/env/hydroacoustic-manual.pdf