RED HILL, Oahu (HawaiiNewsNow) - A new study suggests that the Navy's massive Red Hill fuel tanks are in worse shape than initially thought.
In 2014, 27,000 gallons leaked from one of the Navy's aging tanks.
The Navy recently examined one of the steel tanks that didn't leak. Upon further inspection, officials found corrosion and thinning in seven out of 10 sections that samples were taken from.
The 12-inch square samples were taken earlier this year after scans of the tanks, and testing began in June, the Navy previously said.
The Sierra Club says the steel lining in some places is about half of what it should be. The reduction in thickness is reportedly due to corrosion.
"What we learned today is the Navy's testing reveals the tanks are far more corroded and much thinner than anyone predicted," Marti Townsend of the Sierra Club of Hawaii said.
Environmentalists fear that impacts from another leak could be widespread.
"They're only 100 feet above the aquifer that serves 400,000 residents and visitor on Oahu. If there is another catastrophic leak, the contamination is permanent."
The Sierra Club is suing the state to require more stringent oversight of underground fuel tanks.
They say the Navy's proposal to upgrade the tanks by re-painting them and studying them better is not enough.
Hawaii News Now has reached out to the Navy for additional comment. Navy officials are expected to release a statement Tuesday.
This story will be updated.