Dynegy to use sonar in removal of pipe off Morro Bay coast

The Morro Bay Power Plant.
The Morro Bay Power Plant. The Tribune

The owner of the decommissioned Morro Bay Power Plant will be working to remove a large underwater pipe off the city’s coast.

Officials at Dynegy, the plant’s Houston-based owner, told the city of Morro Bay that the company will be conducting underwater surveying as part of the work to remove a large pipe that allowed oil tankers to connect to the facility and offload fuel to be used to run the power plant.

The surveying will use electronic sonar and a fathometer, “similar to the devices used by millions of boaters and fisherman to monitor water depth and look for fish,” Morro Bay Deputy City Manager Sam Taylor said in a statement.

“Some citizens have been concerned that seismic testing was occurring that involved an underwater air gun, known to be very loud, and potentially harmful to sea life and humans,” Taylor said.

However, company officials say the permitted work, being conducted by the contractor Fugro, will use high frequency pinging to map the ocean floor and won’t hurt any marine life.

The sonar will be at a frequency 2,000 times higher than an air gun used in seismic surveys, according to the company. The higher the frequency, the less the impact, according to company officials. It also will have 10,000 times less decibel power.

“This is a routine survey of a type performed offshore California many times each year, and Fugro is planning and executing this underwater survey in accordance with those permits,” said Ninah Rhodes Hartley, a Dynegy environmental compliance specialist.

Morro Bay city officials said the work may be done from 6 a.m. to 6 p.m. through Nov. 25.