A public hearing is set for Monday, in which the Navy is expected to contest the Hawaii Department of Health’s emergency order instructing it to drain the fuel from its 20 underground Red Hill fuel tanks.

The fuel facility that sits mauka of Joint Base Pearl Harbor-­Hickam has long posed a risk to a major drinking water source for Oahu and is believed to be the source of the current petroleum contamination of the Navy’s drinking water system.

The hearing is scheduled for 8 a.m. via Zoom.

DOH issued its emergency order on Dec. 6 amid hundreds of complaints from users of the Navy’s drinking water system that their water smelled of chemicals or fuel. Residents have complained of vomiting, diarrhea, burning skin, rashes and headaches that health officials say are consistent with drinking or having contact with petroleum contaminated water. Some people have reported that their pets have died from drinking the water.

Secretary of the Navy Carlos Del Toro indicated that he had instructed the Navy to comply with many aspects of the state’s order, including cleaning up the contamination and obtaining a drinking water treatment system. The Navy also said it will obtain an independent assessment of the integrity of its Red Hill Bulk Fuel Storage Facility and implement a final work plan for any needed improvements. But the Navy has taken issue with the requirement that it drain its Red Hill tanks, which military officials say are important for national security.

Red Hill fueling operations have been suspended since Nov. 27. But Del Toro has indicated that this suspension is only expected to persist through the duration of the investigation into the water contamination, which is expected to be concluded in January.

Under DOH’s order, the fueling operations at Red Hill are expected to be suspended for much longer, with the prospect that they may not be allowed to resume at all. DOH has said that after the Navy complies with all aspects of its order, it can then come back to the state and seek a permit for resuming operations.

A hearing on the emergency order was scheduled for this week, but was delayed after the Hawaii Sierra Club and the Honolulu Board of Water Supply filed motions to intervene. The Hawaii Sierra Club says it wants to step in to make sure that DOH doesn’t allow the Navy to get away with half-measures that don’t adequately protect the safety of the area’s water supply.

The Board of Water Supply, which provides water for the vast majority of Oahu, is directly affected by the Navy’s water contamination crisis. They both draw a portion of their water supply from the same aquifer. The Board of Water Supply has shut down its Halawa shaft and two other wells as a precautionary measure to make sure that the contamination doesn’t migrate into its drinking water system.

The Navy has opposed the requests from the Sierra Club and Board of Water Supply to intervene in proceedings and hearings officer David Day, an attorney with the Hawaii Attorney General’s office, is expected to rule on the matter by Sunday.

Regardless of his decision, all parties are being told to prepare for the Monday hearing.

A final decision in the case is expected to be issued quickly. “Due to the nature of the emergency, our hope is to expedite the process to protect public health and the environment,” said a DOH spokeswoman in an email.

However, a decision also could lead to lengthy legal wrangling if any of the parties seek to take the issue to court. Del Toro suggested this month that the Navy is not subject to orders from the state.

The Red Hill facility includes 20 massive, underground tanks, each 100 feet in diameter and 250 feet in height. The tanks have a combined capacity to store about 250 million gallons of fuel, a volume that’s equivalent to about 380 Olympic-­size pools.

Top Navy officials wouldn’t say on Friday, when asked by state lawmakers, how much fuel is currently being stored at Red Hill, citing national security considerations.