The Navy confirmed Thursday that a well near Pearl Harbor is contaminated with a petroleum product, four days after military housing residents began reporting problems with their drinking water.

During a virtual town hall on Thursday night, Pacific Fleet Deputy Commander Rear Adm. Blake Converse said that the service’s Red Hill well had tested positive for petroleum hydrocarbons late Sunday and petroleum vapors on Thursday.

He added that the Red Hill well “had been isolated” since Sunday, meaning the Navy took it out of service.

“One test was taken on Sunday night shortly after this incident was identified to the Navy, and that test identified trace amounts of very volatile hydrocarbons that would normally be associated with JP‑5 [jet fuel] or diesel fuel, more than likely JP‑5 or gasoline,” Converse said.

In a statement released Thursday, the Navy said the sample contained levels of petroleum hydrocarbons “roughly four to ten times below” the level required b …