There are few government mandates more critical to public health than protection of water supplies. This can require some extraordinary precautions to be taken.

Such precautions are necessary in the case of Oahu’s aquifer system, next door to the Navy’s Red Hill underground fuel storage facility, where leaks were detected in January 2014. And now, the prospects for improved water safety in the area are looking better.

The Navy, which manages the storage tanks, has asserted that the leaked oil has not contaminated drinking water, but it was still required to agree to a work plan to reinforce fuel containment. Officials are now reviewing a set of proposals as a key component of the formal agreement it reached with state and federal environmental health authorities in lieu of paying fines.

The Navy negotiated that Administrative Order on Consent (AOC) with the state Department of Health and the Environmental Protection Agency, and finalized it last September.

The leak of 27,000 gallons of fuel oil, so close to the source of much of the island’s drinking-water needs, demands that an aggressive repair route be taken.

The outlook seems encouraging. The critics — including the Honolulu Board of Water Supply (BOWS) — are buoyed by some of the suggested improvements. And, rightly, they are favoring installation of a “tank within a tank” design as the best way to greatly lower the risk of future leaks contaminating water.

Erwin Kawata, program administrator of the board’s water quality division, said that design would leave space between the nested tanks, enabling any leaks to be contained safely, and enabling crews access for routine maintenance and checks.

But, he added, officials are encouraged to see that the Navy is considering a range of options. The original list of 14 proposals was winnowed to six.

According to the recent update report, these include: changing the current tank configuration, keeping the current configuration but adding coatings, complete replacement of the existing steel plates, construction of a new tank inside the existing tank, and construction of a double-walled tank without an accessible outer wall, using regular steel or stainless steel.

Additionally, according to the report, the inspection, maintenance and repair procedures that each option would require will be studied.

In more good news, the Navy, DOH and EPA have reached accord on four new groundwater monitoring wells to be installed near the Red Hill facility, starting this year. And the Navy plans to study the area’s geology and groundwater flow before drilling in search of leaked fuel; this seems a prudent route.

However, another primary concern raised by the board remains: The timetable for the whole improvement planning process is starting to extend — and this is still the early stages of the initial two-year planning period.

The parties to the agreement should ride herd to make sure delay doesn’t become habitual. An allowance of 20 years for making the reinforcements should be shortened rather than prolonged. The tanks were originally built in the 1940s, and the longer improvments take, the greater the risk of future failure, with potentially devastating results.

To quote from the documents accompanying the agreement: “EPA and DOH anticipate opportunities to accelerate the current tank upgrade schedule,” with penalties possible for delays.

Further, transparency of the process is still a paramount concern. The BOWS will not have to sign nondisclosure agreements to take part in meetings set for May — a positive note.

Environmental groups have criticized the agreement for the length of time needed for improvements. On the whole, though, the accord was the surest way to secure improvements that would satisfy federal and state overseers, who have made the persuasive case that the drinking water is still safe.

So far, the Navy is demonstrating a willingness to address public concerns and make the facility more secure.

That’s a good start.