Nearly two years ago, when one of the Navy's Red Hill fuel tank leaked 27,000 gallons of jet fuel, officials were quick to conclude that the spill did not reach the area's water source.
"I have high degree of confidence that petroleum products from this incident have not migrated from the Red Hill tank facility towards the Red Hill well aquifer," Capt. Mike Williamson said in January 2014.
But on Friday, the head of the Honolulu Board of Water Supply said the contamination did in fact hit the aquifer and that readings from monitoring wells had spiked in April.
Ernie Lau, the board's manager and chief engineer, said that in April the monitoring well closest to the leaking tank detected fuel contamination levels higher than those recorded in January 2014 when the leak occurred.
What's unusual is that the tank had been empty for more than a 18 months.
"That indicates signs of petroleum contamination that is pretty high," said Lau. "The groundwater aquifer, which contains the water, is contaminated to various levels from petroleum contaminants below and near the facility."
Lau's comments came during a task force meeting on the Red Hill spill. The Navy recently reached an agreement with the state Health Department and the U.S. Environmental Protection Agency to upgrade its 20 fuel tanks on Red Hill, which hold more than 250 million gallons of fuel.
The aquifer is a large underground layer of water-bearing rock. The aquifers in the Moanalua and Halawa provide up to 25 percent of the drinking water in urban Honolulu.
During a follow-up interview with Hawaii News Now, Lau said the fuel has not reached the Board of Water Supply's Halawa drinking water wells, which are about a mile away from the Red Hill Fuel Facility. But he said if more isn't done to contain the problem, the fuel could pose risks.
"Over the long term, possibly decades, there could there be a movement of fuel in the ground water in the aquifer in our direction. That's a concern," Lau said.
Lau is urging the state and the Navy to place more monitoring wells near its Halawa wells to ensure that the fuel spill isn't migrating that way.
Added state Rep. Chris Lee, who is a member of the Red Hill Task Force and chairman of the House Environmental Protection Committee, "We don't know how far and how fast this is spreading so we just need to keep on top of it and make sure we take action before this enters our drinking water."