Local and federal authorities have ventured into uncharted territory, having signed an agreement giving them some oversight of a once-secret naval installation. The object of the pact is to shape the maintenance and fortification of the Red Hill underground fuel storage tanks that have caused so much worry in recent months.

The reason for the worry is plain enough: In January 2014, 27,000 gallons of fuel oil leaked out from one of the 20 mammoth tanks stored there, in relatively close proximity to the aquifer that supplies much of Oahu’s drinking-water needs.

That was the driving force behind the negotiation of the agreement, known as the Administrative Order on Consent (AOC), struck by the Navy, the state Department of Health and the Environmental Protection Agency.

The concern is a serious one. One goal of the agreement must be to accelerate the pace of improvements over the decades to come, and to do so with as much transparency to the public as possible.

The 20-year timetable for the improvements, following the current two-year planning period to determine which technology would work best, continues to set off alarm bells among officials of the Honolulu Board of Water Supply, who think 20 years is too long, given the urgency of the problem.

The water board raised the issue again last week at a meeting of the Red Hill Task Force, ostensibly to discuss other military field-constructed tanks across the state.

BOWS Manager Ernest Lau, citing groundwater monitoring tests taken in April nearest the leak site, said the levels of petroleum hydrocarbon diesel were elevated at 5,250 parts per billion, above the acceptable level of 4,500 parts per billion.

The Navy underscored that a subsequent test in June showed levels well below the acceptable threshold, and that none of this meant the source of the drinking water itself was contaminated. The water being tested is groundwater in the rocky strata beneath the tanks and is not moving, officials said.

Is the drinking water safe? The parties to the AOC make a persuasive case that it is, at least for now. But these are World War II era tanks, so the public must conclude that time is of the essence where improvements are concerned.

Much of the initial planning will be accomplished in the next two years, said Dean Higuchi, a spokesman for the Hawaii office of the EPA. The pact included assertions that the fixes should be made as quickly as practicable, he said, with the understanding that the agencies would be pushing for them to be made sooner rather than later.

The proponents of the deal argue, correctly, that the planning is key, and that the decision on technology must be made carefully so the solution selected will offer effective protection.

The real issue is the deployment of that solution. The agreement calls for about 40 tasks to be completed within the first three years of implementing the plan — “front-loading” the improvements.

The “frequently asked questions” document summarizing the current plans commit the local agencies to function as the watchdogs of the operation. There are two parts of this responsibility.

One is to keep things moving. According to the FAQ: “EPA and DOH anticipate opportunities to accelerate the current tank upgrade schedule,” with penalties if things fall behind the current schedule.

That is the appropriate stance, but the other is to keep the public informed. In the current planning and “scoping” period, officials are reviewing protocols, likely to include non-disclosure agreements for sensitive information.

Some redaction of documents is inevitable, but the local agencies should serve as public advocates to keep that to a minimum. There is a lot that’s uncertain about how the Navy will proceed in managing this facility better going forward, but one thing is clear. This is a precious water supply for all Oahu residents, who deserve to be kept in the loop about its security.