From the beginning, the Navy’s Red Hill underground fuel tanks have leaked, said David Kimo Frankel, an attorney for the Sierra Club.

In 1949, Tank 16 was leaking 546 gallons a day. On some days that rose to more than 1,550 gallons, he said.

In 1958 a tank leaked 1,500 gallons of fuel. In 1971 there was a 20,000-gallon leak, and in 1980 another tank leaked more than 25,000 gallons, he said.

And there was the 2014 leak of 27,000 gallons, which the Navy said was the fault of a contractor.

“The Red Hill tanks cannot be, and are not operated, in a manner that is protective of our (groundwater),” Frankel said. “There is a practical alternative: build new tanks above ground in a safe location (and) relocate the fuel — just as the Navy did on the mainland.”

Monday saw opening arguments in a five-day contested case hearing debating the merits of awarding a five-year state operating permit for the Navy to continue storing up to 187 million gallons of fuel at the Red Hill Bulk Fuel Storage Facility.

While the Sierra Club believes the 20 tanks should be relocated and the Board of Water Supply maintains they should be moved or rebuilt with secondary containment, the Navy said this is not your grandfather’s fuel farm anymore.

“Since 2014 the Navy has a different facility, both in its physical construct and how it’s operated and monitored each and every day,” said Navy lawyer Karrin Minnot.

Twice a year the tanks are tested for leaks using a method certified by third-party verifiers, Minnot said.

“The Navy’s procedures for inspections and repairs at Red Hill go above and beyond the industry standards,” she said.

When refilling the tanks, there are visual inspections and personnel at the facility that have increased training and certification.

“Additionally, fuel inventories are monitored every minute of every day with sophisticated automated fuel-handling equipment systems and automated tank feeding systems,” Minnot said.

Some say the fuel supply is a crucial — and massive — war reserve for the Pacific that would be hard to replicate with above-ground tanks. The Board of Water Supply said Oahu’s drinking water aquifer, 100 feet below Red Hill, cannot be placed at risk of contamination from a major spill.

The Defense Department has invested over $200 million and plans to spend over $400 million more “to ensure the facilities remain safe,” Minnot said.

Located 2.5 miles from Pearl Harbor, Red Hill has 20 vertically arrayed 250- foot-tall underground storage tanks that were constructed between 1940 and 1943, with each tank capable of holding 12.5 million gallons.

In response to a 27,000-gallon fuel spill in 2014 from Tank 5, the U.S. Environmental Protection Agency and state Health Department negotiated an ongoing administrative order on consent requiring the Navy to make fuel safety improvements.

Much of the concern centers on the tanks’ location 100 feet above the water supply aquifer, which lies in saturated volcanic rock.

In 2018 the Health Department amended its underground storage tank rules to, among other things, require previously exempt field-constructed tanks such as Red Hill to follow state requirements.

The Navy applied for a five-year permit, and the Sierra Club and Board of Water Supply requested a contested case hearing. The permit and consent order are separate procedurally.

Both actions have focused on the age and construction of Red Hill, a single-wall tank system of quarter-inch-thick welded steel plates backed by 2 to 4 feet of concrete.

Board of Water Supply attorney Ella Foley Gannon said that quarter-inch of steel “is really the only meaningful barrier between the fuel” and the environment. And that environment is damp.

The Navy removed 10 sections of tank wall called “coupons,” and “when you look at that … there’s corrosion that’s existing on each one of those coupons,” Gannon said. Many were wet on the backside.

The Navy says the concrete backing provides protection and is helping hold leaked fuel in, “but we know that this was not true … because when there’s been spills the fuel has gotten out of the tank and it’s gotten into the environment,” Gannon said.

“When core samples were taken from rock, there was fuel in core samples from the rock,” she said. Microbial action might attenuate some of the fuel.

Minnot, the Navy lawyer, said evidence shows that “the continuing operation of Red Hill is protective of human health and the environment.”

The 2014 fuel release “was certainly unfortunate, but it was not from corrosion, or deterioration of the Red Hill tanks,” she said.

Contractor error that led to the release “would not be possible under the new and improved tank inspection, repair and maintenance protocol” that was approved by the state Health Department and EPA in 2017, Minnot said. Officials also faulted “ineffective response and oversight.”

The Navy has long maintained that the water from the Red Hill shaft down-­gradient from the fuel farm, and which supplies Joint Base Pearl Harbor-Hickam, is completely safe to drink.

The Navy “is fully compliant with every one of Hawaii’s underground storage tank regulations,” Minnot said.

Frankel, attorney for the Sierra Club, said a Navy report concluded that the probability of a sudden leak of between 1,000 and 30,000 gallons over the next year is 27.6%, with that risk rising to 96% over the next 10 years.

“The Navy cannot be given a free pass to ruin our water,” Frankel said. “The Department of Health must conclude that the Navy’s permit to operate its antiquated and leaky tanks is unacceptable.”