Commanders at the Pentagon determined that an investigation by the Hawaii­-based U.S. Pacific Fleet into contamination of the Navy’s water supply on Oahu “did not include a sufficient review” of previous spills from the Red Hill fuel farm — ordering a “supplemental investigation.”

The Navy announced Tuesday that the probe will be overseen by Rear Adm. James Waters, who was appointed by Vice Chief of Naval Operations Adm. William Lescher. Waters has a background in systems engineering.

The Pacific Fleet investigation was ordered by Navy commander Adm. Samuel Paparo in December after fuel operations were suspended at the underground Red Hill fuel storage facility and the Red Hill water well was shut down.

Service members and military families on the Navy’s water system had begun reporting the smell of fuel in the water and feeling ill not long after a spill at the facility on Nov. 20 in which 16,000 gallons of water and jet fuel was released. The Navy’s water system on Oahu serves 93,000 people and includes military housing areas as well as schools, businesses and the Kapilina Beach Homes — a civilian residential community in what was once a military housing area.

The contamination crisis led the Honolulu Board of Water Supply to shut down its Halawa Shaft for fear the contamination would spread to Oahu’s system. Due to that shutdown, city officials Thursday called on all Oahu water users to voluntarily reduce water consumption by 10%.

Defense Secretary Lloyd Austin earlier this month ordered the Navy to defuel and permanently shut down the Red Hill facility.

The Pacific Fleet report on its investigation was submitted to Paparo on Jan. 14 and forwarded to the Pentagon. Navy officials had said they would release a summary of it but would not make the report itself publicly available. However, the Navy backtracked after a barrage of criticism from Hawaii lawmakers and community leaders. But military officials have declined to say when the report would be released to the public.

In testimony to state and federal lawmakers in the wake of the crisis, Navy officials have said they now believe that the fuel from a May spill made its way into a lower tunnel where it was pumped into a pipeline that’s part of the facility’s fire suppression system. Months later, in November, that pipeline burst, spilling fuel into a drain used to release rainfall back into the environment.

“Adm. Lescher directed the supplemental investigation because the initial command investigation, while sound in many respects, did not include a sufficient review of actions the Navy took in response to the May and November releases,” the Navy’s top spokesperson, Rear Adm. Charlie Brown, said in a Tuesday media release.

When asked to clarify what Lescher considered to be lacking in the Pacific Fleet’s report, Navy spokesperson Sean Gano said that the admiral “determined that a supplemental investigation would identify facts relevant to the Navy’s response to the May and November events, as well as the appropriateness of the actions taken.”

“The Navy’s immediate priority was to respond to the crisis, ensuring everything possible to safeguard the health, safety, and well-being of our people, their families, and our community neighbors was being done,” said Gano. “An investigation into those same response efforts may have hampered or interfered with those response efforts. The supplemental investigation will ensure that the final report thoroughly addresses both the response taken and the appropriateness of the response.”

The Navy has faced heavy criticism for its handling of the both the Red Hill facility’s maintenance and its response to the spills. In the weeks leading up to the contamination of the water supply, emails leaked to local media showed top officials had sought to hide issues raised by Navy personnel and to publicly downplay safety concerns.

In November an email obtained by the Honolulu Star-Advertiser showed that a senior Navy officer had raised concerns about multiple leaking valves and pipes ahead of the May spill, but Navy officials did not appear to share this information with the state.

Last month U.S. Rep. Kai Kahele, D-Hawaii, told the Star-Advertiser’s “Spotlight Hawaii” livestream program that when he requested security video footage of November’s spill, Navy officials told him it didn’t exist because the cameras that should have documented it had been inoperable since January 2021 after a contractor inadvertently severed a cable that provides power to 44 out of the 57 closed-­circuit cameras in the facility.

The Navy’s latest investigative effort adds to several other ongoing investigations.

On Dec. 20 the Pentagon Inspector General’s Office announced it had launched a probe into the operations, maintenance and safety of the Red Hill facility. In February, U.S. Environmental Protection Agency Administrator Michael Regan announced at a news conference in Honolulu that his agency would also investigate the facility.