Environmentalists are using a bill at the state Legislature to pressure the military to do more and do it sooner to protect a major Oahu groundwater source from future leaks from the Navy’s enormous fuel tanks at Red Hill.

The state Health Department is drafting new rules governing underground storage tanks, and Senate Bill 2930 would mandate that those new rules require the military to upgrade to a “secondary containment” system — such as double­-walled tanks — by a date yet to be determined. The original bill set a deadline of 2028 for the new safeguards to be in place.

One of the massive tanks at the Navy’s Red Hill Bulk Fuel Storage Facility leaked 27,000 gallons of jet fuel in 2014, but Capt. Richard D. Hayes III said in published remarks this week that the 2014 leak “came about due to contractor errors, poor oversight and a slow response to alarms.”

“The tank itself was not defective. We learned from that event and instituted safeguards, checks and balances, and better procedures that we continue to refine,” Hayes wrote.

The Navy already has an agreement with the state and the U.S. Environmental Protection Agency to upgrade the massive Red Hill tanks by 2037, but no decision has been made yet about exactly what sort of upgrades will be required.

Six different options for upgrades are being considered, including three that involve double-walled secondary containment solutions for the 20 tanks. Each of the tanks can hold up to 12.5 million gallons of fuel.

The Sierra Club of Hawaii and other environmental groups are pressing for what everyone acknowledges will be extremely expensive tank improvements to prevent any further fuel leaks.

“Government officials slept while the water in Flint, Michigan was contaminated,” said Marti Town­send, director of the Sierra Club of Hawaii, in written testimony to lawmakers. “We cannot repeat that mistake here. The antiquated, leaky tanks at Red Hill need to be upgraded to secondary containment immediately, or they should be removed.”

The Honolulu Board of Water Supply also “strongly supports” the bill.

“If the Red Hill facility wants to continue storing large volumes of fuel just 100 feet above our aquifer, then the BWS believes the secondary containment tank-within-a-tank design is the proper way to prevent releases into the environment,” wrote BWS Manager and Chief Engineer Ernest Y.W. Lau. “Otherwise, the tanks should be relocated.”

Rear Adm. Brian Fort told lawmakers Tuesday the Red Hill facility “is absolutely vital to our nation’s national defense, and the United States Navy is absolutely committed to never spilling another drop of fuel.”

He told lawmakers the Navy and the Defense Logistics Agency have spent more than $33 million complying with the agreement the Navy signed with the EPA and the Health Department, and has spent more than $250 million improving the Red Hill facility since 2005.

Those improvements included groundwater and soil vapor monitoring systems, structural re-enforcement of tunnels and passageways, and more, he said.

“Over four years after the 2014 release, Red Hill is not an urgent or catastrophic public health crisis,” Fort said in written comments. “We are upgrading Red Hill in a thorough and logical way to prevent mistakes. Mistakes caused the 2014 release, not a rusty or old tank.”

The House Energy and Environmental Protection Committee deferred action on SB 2930 until Thursday.