Navy officials said Thursday that they’re committed to finding a way to install a secondary containment system around their massive, underground fuel tanks at Red Hill where 27,000 gallons of fuel leaked in 2014 — and if they can’t, they will remove the fuel around the year 2045.

However, critics of that plan, including the Hawaii Sierra Club, say that’s just the Navy’s attempt to wiggle out of legal requirements that it significantly upgrade its nearly 80-year-old tanks by 2037 or relocate them.

A top official with the U.S. Environmental Protection Agency said his agency has not signed off on the Navy’s proposed timeline.

The Navy last month provided federal and state regulators with its long-awaited recommendations for upgrading its Red Hill Underground Fuel Storage Facility near Pearl Harbor. The proposal, required under a legal agreement forged between the Navy, EPA and state Department of Health after the 2014 fuel spill, includes sticking with the Navy’s single-walled steel tank liners while permanently adopting an improved program for cleaning, inspecting and repairing its 18 active tanks.

The plan disappointed environmentalists and officials with the Honolulu Board of Water Supply who have been pushing the Navy to install a secondary containment system in the tanks to provide extra protection in the event of leaks or relocate them entirely.

The Navy concluded that double-lining the tanks would be too expensive and provide limited benefits.

Marc Delao, commanding officer of Naval Facilities Engineering Command Hawaii, briefed government officials and the public on the plans Thursday during an annual Fuel Tank Advisory Committee meeting at the state Capitol. Delao said that while the Navy and its partners were unable to identify a practical technology that could provide a backup containment system for the fuel tanks, the Navy would continue the search as technologies evolve.

The Navy is committed to “finding a secondary containment solution — applicable, practicable — and if that cannot be achieved, moving off the aquifer in the 2045 time frame,” said Delao.

Marti Townsend, director of the Hawaii Sierra Club, said the Navy is basically seeking an extension while providing no guarantee that it will actually remove the fuel around 2045.

“It’s not a commitment,” said Townsend of the Navy’s 2045 date. “It’s a, ‘If we can’t find a better solution based on the futuristic technology that we are dreaming up, then we would consider moving it in 2045.’ So they basically want to extend the period for research and development of newfangled technologies to allow them to keep the tanks in place beyond the current date set by the (legal agreement).”

The legal agreement, known as an administrative order of consent, requires the Navy to upgrade its tanks as quickly as possible and stipulates that tanks that haven’t been upgraded by 2037 will be taken out of service. There is no requirement that the Navy install secondary containment systems, basically a tank-within-a-tank solution. Critics of the Navy’s current plan for improving its tanks say it basically involves sticking with the status quo while installing better leak detection and monitoring.

The Navy’s overall plan for improving its tanks and leak detection system still must be approved by officials with the EPA and state Health Department.

Separately, new administrative rules approved last year by the Department of Health require all underground fuel storage tanks, including Red Hill, to have secondary containment systems by 2038. The health director can approve an alternative design that protects the environment.

Ernie Lau, manager and chief engineer of the Honolulu Board of Water Supply, pressed officials with the EPA and Health Department on whether they had given tacit approval to the Navy’s new time frame.

Steven Linder, a program manager for the EPA’s underground storage tank program, said the 2045 deadline is something his agency is considering but hasn’t approved.

Linder said the available technologies for double- lining the tanks at Red Hill was limited given their unique design.

“One of the challenges with Red Hill … is just getting the material into these huge tanks,” he said. “They were built at a time when an immense number of people were involved. There were a lot of people killed in the process of building Red Hill. It was a very dangerous environment, and nowadays people don’t do things like that. The process of trying to do a major project in these tanks is very, very difficult.”

Keith Kawaoka, the Health Department’s deputy director for environmental health, conceded that the 2045 date was a “new line in the sand.” He said it was the Health Department’s preference that all of the fuel be removed from the Red Hill facility by that date.

Leaks from the Red Hill tanks are of particular concern because the facility sits just 100 feet above a major source of drinking water for much of Oahu. If that aquifer is polluted by a major failure at one of the Red Hill tanks or by a migrating plume of leaked oil, it could be cost-prohibitive if not impossible to clean up, state officials have said.

Each tank holds about 12.7 million gallons of fuel and is roughly the size of Aloha Tower.

Recent studies commissioned by the Navy found that there is a 34% chance that at sometime in the next 100 years, there will be a major fuel leak at the facility. The risk of small, chronic leaks at the facility is much greater.

Lau urged the Navy to move to secondary containment or consider alternative sites for the tanks.

“I’m getting a little frustrated here because we have been working at this thing since 2015, and we are getting tired of having to say the same concerns over and over again and not being heard,” said Lau.