Porous. That’s how the U.S. Navy describes Red Hill’s basalt rock that has absorbed the 27,000 gallons of fuel that leaked from one of its underground tanks in January 2014.

And porous also describes the Navy’s action plan to remedy the situation and shore up its 18 active fuel tanks — or lack thereof.

The Navy is still working to find out where the leaked fuel went and whether it can be cleaned up.

Time is of the essence: the World War II-era fuel tanks sit just 100 feet above an aquifer that supplies 25 percent of urban Honolulu’s drinking water.

The Navy’s seemingly slow pace has frustrated elected and government leaders, environmentalists and community members who are rightly calling for quicker action.

Granted, the Navy entered into a consent agreement with the Environmental Protection Agency and state Health Department a year ago that lays out a series of studies and criteria for upgrading the tanks. More concrete plans on how to upgrade the aging tanks or better monitor for leaks aren’t expected to be finalized for another couple of years.

With uncertainty mounting, though, the timeline should be ratcheted up to allay concerns.

Gary Gill, former deputy director for environmental health at the Health Department, who was formally involved in negotiations over Red Hill, said the risk of the Red Hill fuel tanks to Oahu’s drinking water “gets worse every day” given the age of the facility.

Environmentalists have grown impatient.

“We want to see these tanks be leakproof and the contamination that has already escaped into the environment to be cleaned up,” said Marti Townsend, executive director of the Hawaii Sierra Club.

The Navy, however, says the fuel has been absorbed into millions of little cracks and fissures. So the remedy, if there is one, is still being researched.

Capt. Ken Epps, commander of Naval Supply Systems Command Fleet, told the Star-Advertiser that if the studies show it’s not feasible to clean up the fuel, then the Navy will study how quickly it is expected to degrade in the environment over time.

But if no cleanup is “feasible,” there is no telling how many more years will have passed before such a study is concluded.

For now, there is value in the Navy’s installation of four new monitoring wells to gauge whether fuel products are migrating toward drinking water wells, and adding two more can only help.

Still, we agree with the Honolulu Board of Water Supply that there needs to be a more extensive monitoring plan.

Nearly three years have passed since the fuel leakage but the public has been presented with partial solutions and no proactive measures.

It’s no wonder community members who attended a meeting Thursday to discuss the issue at times grew hostile toward the Navy.

While Red Hill’s contamination is a wholly different situation from that in Flint, Mich., where lead seeped into the drinking water and caused a massive public health crisis, steps must be taken here to avoid the kinds of missteps by government officials there. One key lesson learned from Flint: Transparency and open communication are critical.

Following the Navy’s disclosure of the major fuel leak in January 2014, media investigations revealed that the aging infrastructure actually had a long history of leaks and that the military for years had been concerned about the tanks’ deteriorating conditions and the possibility of a catastrophic failure.

That kind of track record only diminishes the public’s confidence.

The Navy must be forthcoming at each juncture moving forward.

Notwithstanding the Navy’s painstaking research on how best to shore up the facility, it would seem logical for its focus to be narrowed on double-lining the 18 active tanks to avoid any further leaks, as regulators have suggested.

But Epps said the Navy is still looking at whether that is feasible.

While environmentalists are pushing for the Navy move the fuel tanks to another location if unable to guarantee further leaks, the chances of that are likely slim to none.

Each of the tanks is big enough to envelop Honolulu’s Aloha Tower — and the Red Hill facility, Epps said, is critical to national security given recent activity in countries such as China and North Korea.

Securing the structure and stability of the tanks within a tighter time frame must become the Navy’s priority. Leakproofing the tanks cannot be done on a decades-long timeline — that, simply, is not feasible.