Introduction & Objectives

Sounds produced by humans have the potential to affect the behavior and physiology of marine species, including fish and marine mammals. Pile driving is a significant component of marine construction projects known to produce high sound levels. Current data on sound levels from pile driving have mostly been collected from projects in California and Washington states. However, the different bathymetric and sediment conditions on the east coast may produce lower sound levels during similar pile driving projects in these locations. This project seeks to understand the sound produced by both vibratory and impact driving methods on various types of piles at Navy installations along the US East Coast.

Technical Approach

This project has been contracted to HDR, Inc., and subcontracted to Illingworth and Rodkin, Inc. Sound measurements are collected at near (~10m) and far (~150m) ranges from pile driving with calibrated hydrophones and sound level meters. Both airborne and underwater noise levels are analyzed. Results include broadband sound pressure levels and 1/3 octave band spectra for inclusion in analyses of the effects of pile driving sound on marine species.

Progress & Results

In May 2013, researchers conducted monitoring on two installations, measuring vibratory installation of steel sheet and H-piles at JEB-LC and impact testing of a single concrete pile at Craney Island. Underwater measurements were made at short- (approximately 10-m) and long-distance (approximately 50- to 200-m) ranges from the piles being driven at both installations. Airborne noise measurements were taken only at JEB-LC. For the steel piles at JEB-LC, the source levels for vibratory driving ranged from 115 to 121 decibels referenced to 1 micro Pascal root mean square. For the impact driving of the concrete pile, source levels averaged between 162 and 169 decibels referenced to 1 micro Pascal root mean square.  

Researchers conducted similar monitoring efforts at the Philadelphia Naval Shipyard and Naval Station Norfolk in fall 2014. At the Philadelphia Naval Shipyard, monitoring included large (48-inch diameter) steel pipe piles, while monitoring at Naval Station Norfolk targeted vibratory driving of small diameter (12- to 16-inches) timber piles and impact driving of 24-inch diameter square concrete piles. 

In 2015, measurements were taken at the temporary pier constructed during training for the Joint Logistics Over The Shore exercise performed at JEB-LC. In September 2015, measurements of vibratory extraction of 24-inch steel pipe piles were taken. Vibratory extraction measured approximately 145 decibels referenced to 1 micro Pascal root mean square. Installation of piles for JLOTS was measured during April of 2016. Average sound levels during installation were 196 dB re 1µPa RMS, and 212 dB re 1µPa peak   

The interim reports from each monitoring event and the compared data have been published in a single comprehensive final report, which is now available for download (Illingworth and Rodkin 2017).