Roselius said air district officials would know more this afternoon about whether the fire was still impacting air quality in the area, but recommended that residents continue to take steps to avoid breathing the smoke.
People living downwind from the fire should keep their doors and windows closed and set their air conditioners on re-circulation, Roselius said.
The fire began at about 5:45 p.m. at 6337 Brentwood Blvd. About 70 firefighters worked to put out the fire and had it contained by 7:18 p.m.
About 50 people were ordered to evacuate their homes and a shelter-in-place warning was issued for other nearby residents, Contra Costa County Fire Protection District Battalion Chief Steve Maiero said.
Evacuation and shelter-in-place orders were lifted shortly before 9 p.m., Maiero said.
Firefighters were still at the scene this morning extinguishing hot spots.
State Highway 4, also known as Brentwood Boulevard, has been reopened between Sunset and Delta roads. It was closed so that fire crews could extend hoses to fight the fire.
The cause of the fire is still under investigation.