A large oil sheen in San Pablo Bay, which feeds water into the Carquinez Strait in Martinez, was detected Wednesday morning.
The sheen was discovered around 8 a.m. near the Phillips 66 Rodeo Refinery Marine Terminal. The refinery temporarily shut down operations and notified the National Response Center and the U.S. Coast Guard.
It is believed an oil tanker berthed at the marine terminal released crude oil into the bay.
Coast Guard crews were busy Wednesday laying down a 1,000 foot boom to contain the oil surrounding the tanker.
An investigation is underway that may link the oil spill to strong odors detected around Vallejo Tuesday night that sent several people to the hospital and prompted a shelter in place.
The Vallejo Fire Department said gas monitors were registering at safe levels by Wednesday, but the department asked Vallejo residents to close their windows and turn off air conditioning units.
Meanwhile, environmental groups like the San Francisco Baykeeper are keeping a close eye on the cleanup and area wildlife. It’s unclear what caused the spill or how much it has spread, but there will be an impact to area fish, marine mammals, sea birds and other wildlife, the group stated.
The exact volume of material released is still being determined and the incident remains under investigation, Rodeo refinery officials said.
Ferry service between Vallejo and San Francisco was delayed Wednesday due to the oil spill investigation.