State raises concerns about tugs to be used for oil tanker escort

State environmental regulators are raising concerns about tugs being built to prevent an oil spill in Prince William Sound, saying the "very limited" and "confusing" information provided so far indicates the vessels may have "substantial" design deficiencies.

The concerns are laid out in a Feb. 22 letter from the Alaska Department of Environmental Conservation to Alyeska Pipeline Service Co., operator of the Valdez Marine Terminal, where North Slope crude oil is loaded onto oceangoing tankers, and to PWS Response Planning Group, composed of oil shippers such as BP Oil Shipping Co. and Polar Tankers, owned by ConocoPhillips.

The issues broadly echo themes reported separately in January by marine engineer Robert Allan, a consultant hired by Prince William Sound Regional Citizens' Advisory Council, the official oil-spill watchdog group for the sound.

Allan had said he had concerns about overall performance design and testing for five escort tugs and four support tugs being built in Louisiana and Mississippi, and whether they could handle Alaska's rough weather.

Alyeska said Allan's views were based on limited, preliminary information about the tugs' proposed performance, and that improvements were underway.

DEC's approval of the barges, escort tugs and general-purpose tugs is required as Alyeska seeks to transfer the tanker-escort and other oil-spill prevention and response duties to Louisiana-based Edison Chouest.

Florida-based Crowley Marine has provided the service under contract with Alyeska since 1990, the year after the Exxon Valdez oil spill occurred. Alyeska plans to replace Crowley with Edison Chouest starting July 2018.

The points made in the letter are based on a "preliminary review" by the state, said Candice Bressler, DEC public information officer, on Wednesday. The state's concerns are related to the lack of available information about expected tug performance and operation.

DEC's letter said that based on the information received so far from Alyeska, the department is concerned the organizations "may not be conducting model testing, simulator testing, numerical testing or full-scale testing based on PWS or Gulf of Alaska conditions or requirements."

"If there is not adequate proof of performance in the critical areas of tanker escort and response, the department will be unable to approve the new escort vessels and response system until this requirement is achieved," says the letter, written by Pete LaPella, a DEC environmental program specialist in Valdez.

In an interview Wednesday, LaPella said there is no deadline for the information — Alyeska could submit a complete package of information at any time.

"We're trying to help them along and make sure they understand what they need to submit," LaPella said.

The agency made three "detailed requests" for information in September about the vessel and barge designs and their intended use, according to the letter. Alyeska responded four times through Dec. 14, providing "some information." But "significant" details were lacking.

"All of the supplied reports concerning vessel performance are hypothetical and speculative since they are not supported by clear documentation and modelling," says the letter, signed by Graham Wood, manager of DEC's prevention, preparedness and response program.

"Reviews of the very limited data provided to date indicate that substantial vessel design deficiencies may exist, particularly in the area of winter operations," the letter says.

The tugs must meet the performance criteria for the Sound and the Gulf, as described in the Prince William Sound Tanker Oil Discharge Prevention and Contingency Plan and the Valdez Marine Terminal Plan, the letter notes.

Alyeska has "provided a great deal of information" to the department about the vessels and the transition, with regular, ongoing discussions, said Michelle Egan, director of Alyeska's corporate communications.

Alyeska has arranged meetings with the department and Edison Chouest experts, to "fully understand" what details the state wants so they can be provided, she said in an email.

She said Alyeska remains confident in its plans and believes the vessels are a big step forward for the prevention and response program in the Sound.

The citizen oversight group has also recently said the building of new vessels, including two open-water response barges, is a "significant improvement" over the old system, despite the group's concerns about tug design.

"Alyeska has been responsive to the concerns identified, and has stated that some modifications are already being worked," said Donna Schantz, executive director for the council, in a Feb. 13 statement.

Alex DeMarban

Alex DeMarban is a longtime Alaska journalist who covers business, the oil and gas industries and general assignments. Reach him at 907-257-4317 or