Recently EPI Group’s Environmental Manager, Heidi Etter, assisted Subacoustech Environmental on a BOEM funded project aimed at making real-time measurements of underwater sound generated during construction activities for select offshore wind facilities. This phase of the BOEM project was to provide sound monitoring for pile driving operations for the Coastal Virginia Offshore Wind (CVOW) project located 27 miles east off the coast of Virginia Beach, VA. This was part of the first phase of the project where Dominion Energy partnered with Orsted Energy are developing two 6-megawatt wind turbines. The monopile foundations were installed on the seabed by impact pile driving and the project used sound mitigation bubble curtains on one of the monopiles and no sound mitigation on the other. The purpose of the study is to investigate the effectiveness of utilizing bubble curtains to reduce underwater sound levels during piling operations.
Bubble curtains are used during pile driving operations to reduce high sound levels. The bubbles absorb sound energy to reduce underwater sound levels from such activities. A ring is placed around the area to be pile drived and air is sent through the system from closely spaced release points which creates a wall of bubbles around the pile.