MOANALUA, OAHU (HawaiiNewsNow) - The Navy just finished what is called "vacuum box" testing of the Red Hill fuel storage tank that leaked thousands of gallons of jet fuel, to find where air was flowing through the wall of the underground cylinder.
"We put a box over the top of the anomaly. We sealed it to the side of the tank and we drew a vacuum on it. If it held the vacuum it would hold air and therefore it would hold fuel;" Navy Region Hawaii chief engineer Capt. Mike Williamson said.
The Navy found 15 defects, tiny openings that may have been caused by recent maintenance.
"It could range from small pin-hole leaks around existing welds," Williamson said.
In all the Navy found 45 areas in the tank's interior that appeared "suspect." The tank is 200 feet tall and 100 feet in diameter. In January, the Navy said it may have leaked up to 27,000 gallons of jet fuel.
"Our teams are taking a good hard look to understand if the 15 pin-hole leaks that we've identified could account for the 27,000 gallons that may have left the tank," Williamson said.
Since the leak happened, concern has been over whether drinking water was contaminated. The Navy said water in its Red Hill well is safe. The Board of Water Supply has done several tests on its wells.
"The last round of testing was done in April. Those tests came back negative for any sort of contaminants," spokesperson Jill Kuramoto said.
The storage tank that leaked is one of 20 in the underground facility that was built in the 1940s. Each tank can hold over 12 million gallons of jet fuel. The Navy will next test the tank's pipe pressure.
"We have an area at the bottom of the tank where the fuel is pumped into the tank and withdrawn from the tank, where those pipes work their way through the concrete," Williamson said.
He said fifteen other underground tanks at Red Hill hold fuel and none are leaking.