ANCHORAGE - Alaska's U.S. senators have filed a bill that would maintain a requirement for every oil tanker leaving the Valdez marine terminal to be escorted out of Prince William Sound by two response tugboats.
Republican Lisa Murkowski and Democrat Mark Begich introduced the bill Thursday.
Alyeska Pipeline Service Co. now provides two-tug service as part of its response plan.
However, the plan expires in 2012 and watchdog groups fear the industry may attempt to lower the requirement to one tug to save money.
Murkowski and Begich said the current system has worked well since it went into effect after the Exxon Valdez oil spill in 1989 and they do not think it should change.
"I think we want to make sure we do not run any unnecessary risk, and even though the tankers may be doubled-hulled, things can happen," Murkowski said.
"Having just the double-hulled tankers is not the only answer," Begich said. "You have to have these dual tugs moving in and out with the tankers. In the past, we have already seen the benefit."
Alyeska officials say tankers have operated safely since the spill.
"I think we've escorted about 11,000 tankers through the sound successfully, so we're doing a good job and we'll continue doing it," said Alyeska spokeswoman Michelle Egan said.
"We currently provide two escorts for each tanker, whether its doubled-hulled or not, and will continue to do so as long as its part of the response plan."
Federal law demands single-hulled tankers have two-tug escorts, but the last single-hulled ships in the fleet are set to retire in 2012.
Watchdogs are concerned about what will happen after that.
"Looking down the road for the long haul, it was clear that something needed to be done, so this is what we decided to do," said Stan Jones, spokesman for the Prince William Sound Regional Citizens' Advisory Council. "There have been repeated signals from the industry in the past that they would be interested in cutting the escort system."
Alyeska officials said they have not been out front pushing to reduce escort tugs.
The Prince William Sound Regional Citizens' Advisory Council says it has heard industry calls for a risk assessment on tug escorts, which could be a step to build the case to reduce escorts.