When the equipment failed, the refinery began using its flare to burn off excess fuel.
The problems continued and the refinery sent more and more material to the flare until, at about 2:30 p.m., officials issued an advisory for local residents.
Sawyer said he believes the flare might not be able to burn up the amount of material being released and some un-combusted odors and hydrocarbons could be impacting the community.
Sawyer said health officials were not issuing a shelter-in-place warning at this time, but warned that people with respiratory illnesses like asthma or emphysema could be affected by the release of the materials.
If the problems get worse, a shelter-in-place warning could be issued. Residents would be notified with sirens and telephone calls.
The refinery is located at 1380 San Pablo Ave. in Rodeo