The Navy on Thursday laid out plans for a “double- wall stainless steel” tank system at the Red Hill fuel farm — accelerating its goal of providing secondary containment to keep the aged tanks where they are in the face of criticism directed at a less comprehensive proposal to prevent fuel spills.

If testing proves successful, the Navy could begin installation into a tank at Red Hill as early as late next year, Capt. Gordie Meyer, commander of Naval Facilities Engineering Command Hawaii, said at a Chamber of Commerce Hawaii military partnership conference.

“We are excited about our engagement with a commercial company to potentially adapt their proven technology to support secondary containment — and I’ll iterate, this is not a coating, but a proposed double-wall stainless-steel product with monitoring between the walls,” Meyer said.

The Navy solicited industry solutions to achieve secondary containment, and proposals were received from 16 companies, Meyer said during the virtual conference.

A product from Gaztransport &Technigaz North America, a subsidiary of a Paris-based company, was selected.

“This company has a successful track record providing similar solutions to tanks larger than Red Hill in the liquefied natural gas shipping industry, and they’ve been used in extremely harsh and dynamic conditions,” Meyer said.

The Honolulu Board of Water Supply, a critic of the fuel farm’s operation above a groundwater aquifer that supplies a large chunk of Oahu with drinking water, said Thursday it had not seen the plan and needed to review it.

But if installed, the double-wall tank plan would seem to go further toward satisfying the Water Board’s earlier concern — at least in terms of a late-2019 position after the Navy proposed a remediation plan keeping the existing steel single-wall tanks.

“The Navy’s preferred single-wall (tank upgrade alternative) is nowhere near equivalent to the actual secondary containment provided by a tank-within-a-tank structure … that would prevent leaks from reaching the environment,” the Water Board said at the time.

The Navy in November said that since the submission of its single-wall remediation plan, it had “begun working with industry to determine the feasibility of existing technologies that could potentially provide for secondary (fuel) containment.”

Located 2.5 miles from Pearl Harbor, the Red Hill Bulk Fuel Storage Facility consists of 20 vertically arrayed 250-foot-tall underground storage tanks that were started before the Dec. 7, 1941, attack on Oahu. The tanks were finished in 1943.

The facility, which the EPA said “is unlike any other in the United States,” can store up to 250 million gallons of fuel.

In response to a 27,000- gallon fuel spill in 2014 from Tank 5, the EPA and Health Department negotiated an enforceable agreement known as an administrative order on consent, requiring the Navy and Defense Logistics Agency to make infrastructure improvements.

Much of the concern centers on the tanks’ location 100 feet above the water supply aquifer, which lies in saturated volcanic rock. The Sierra Club of Hawaii says it is the principal source of drinking water for over 400,000 residents from Ha­lawa to Hawaii Kai.

The Sierra Club recently called Red Hill a “Frankenstein that threatens to ruin our drinking water supply. The best thing they can do is retire the facility and relocate the fuel.”

Meyer said the Navy continues to pursue new initiatives to improve protection for Red Hill — including the secondary containment plan — that run “in parallel” with the consent order.

“The Navy firmly believes that the proposal in the tank upgrade alternatives decision document is protective of the environment and public health,” Meyer said in a follow-up email.

The Navy selected the least expensive of six tank upgrade options and “the least protective,” according to the Sierra Club.

In its “tank upgrade alternatives” decision document from 2019, the Navy said it would at some point implement “double-wall equivalency secondary containment” — or remove fuel from Red Hill in approximately the 2045 time frame.

But it also admitted that “although this technology does not currently exist to allow a fiscally-responsible approach, Navy is committed to finding a solution for secondary containment.”

Meyer said the Navy is still evaluating the potential commercial double-wall tank plan. If it proves feasible later this year, a scale model could be developed, followed by actual installation into a prototype tank at Red Hill.

GTT North America said in a previous release that it would work with the Navy to design a “continuously monitored membrane barrier system” to extend the life of the Red Hill tanks.

“I’ll reinforce that we are in the early stages of this effort, and it’s still unproven, but we are cautiously optimistic on the potential that GTTNA could provide a solution to our secondary containment at Red Hill,” Meyer said.