Navy officials said Thursday they are still not certain that 27,000 gallons of jet fuel leaked from an underground storage tank at Red Hill in January, noting that other factors may have caused a discrepancy in what they had expected to find in the tank and what was actually measured.
That was one of the key messages that Rear Adm. Rick Williams, commander of Navy Region Hawaii, and regional engineer Capt. Mike Williamson gave to Honolulu Mayor Kirk Caldwell and Board of Water Supply Manager Ernest Lau during an hourlong briefing at Honolulu Hale on Thursday.
At a joint news conference after the meeting, Williams said it might take up to a year to complete the investigation into why manual measurements detected a discrepancy in the tank’s monitored level Jan. 13.
To date, there has been no indication a diesel fuel leak contaminated the groundwater aquifer. But officials from the Board of Water Supply and state Department of Health have raised strong concerns about the possibility that a leak, either the one that may have occurred in January as well as any future leaks, might reach and contaminate any of five nearby city water wells that account for as much as 11.5 percent of Oahu’s daily supply. They’ve also noted that the Navy acknowledges that, historically, as much as 1.2 million gallons have been released from the tanks since the 1940s.
"Our focus right now is … on identifying what caused those fluctuations in tank level indication upon the filling process from December to January," Williamson said.
Tank 5, one of 20 World War II-era tanks with a 12.5 million-gallon capacity at the Red Hill facility, had been offline for about four years as part of a "clean, inspect and repair" maintenance cycle and began to come back online in December.
The level change could also have been caused by water that had collected in the space between the steel fuel tank and a concrete casing that surrounds it, Williamson said.
"When you take a tank that’s been empty for a period of time, in this case four years for Tank 5, we expect some differential in height as we’re filling the tank, as the tank expands and as any material — water — that may have intruded in the interstitial space may work its way back out of this concrete," Williamson said. "So you have this steel tank with a concrete encasement around it. And while that tank was empty, you could have had water, conceivably, work its way in that interstitial area (space). And so as we filled the tank, that water could have worked its way back out of that interstitial area."
The 5.5-inch difference in level in a 225-foot tall tank would amount to about 27,000 gallons, thus the possibility of how many gallons may have leaked if there was a leak, Williamson said.
Caldwell said he’s pleased that the Navy, state and city officials are working cooperatively to find answers.
"I come away feeling that we don’t have all the facts yet to verify whether there really was a 27,000-gallon leak, that there could have been an adjustment in the tank," Caldwell said. "And testing has not proved one way or another conclusively what has occurred. We want to get that information; they want to get that information; and that information will then be shared."
On Wednesday state Deputy Health Director Gary Gill told City Council members that Navy officials informed his agency last week that preliminary tests, prompted by the January incident, showed high levels of diesel fuel in a test well at Tripler Army Medical Center, about half a mile southeast from the fuel storage facility. Gill and Lau said that finding, regardless of whether it came from Red Hill, posed a new and heightened concern because the Tripler well is only 3,500 feet from the city’s Moanalua water wells.
Williams, on Thursday, said it would be "premature" to say the elevated diesel level was linked to a leak from Red Hill.
"We’re trying to understand exactly what is contributing to that," he said, noting that engineers have until now believed that the flow of underground water is from Tripler toward Red Hill, not the other way around. "So we’re concerned about that as well."
The Tripler well is near where a hospital landfill and gasoline stations once existed.
The Navy is doing additional tests to confirm the initial finding of diesel.
Williamson said money is available for the Navy to address issues that may need remedying, although secondary containment measures that are being suggested by some agencies may be difficult. "Right now technology does not exist off the shelf to be able to implement a secondary containment," he said, stressing that best available technology is now used to protect against leaks and to detect them when they do occur.
Contractors are now doing a thorough examination of Tank 5, Williamson said. The investigation could take up to a year or could wrap up sooner "if we find something."
Lau, the BWS manager, said he was pleased to learn that Navy officials are open to the idea of drilling more monitor wells on both sides of the fuel storage facility.
Gill on Wednesday said consideration should be given to the long-term possibility of shutting down the 144-acre Red Hill fuel tank facility.
Lau said there was no discussion about that topic at Thursday’s meeting.
Tom Clements, a Navy Region Hawaii spokesman, said after the meeting, "The Red Hill fuel facility is a national strategic asset and continues to provide vital, secure fuel storage for ships and aircraft of U.S. Pacific Fleet and other military branches."
