The fire was reported at about 2:30 p.m. on Saturday at the Recology Sonoma Marin facility near the intersection of Standish and Robles avenues, not far from the SMART/Northwestern Pacific rail line, firefighters said.
Rincon Valley Firefighters were helping put out the fire, which had spread to nearby vegetation.
No injuries had been reported by 3:45 p.m. No other information was immediately available.