SAN JOSE -- Mountains of chipped bark mysteriously caught on fire late Sunday afternoon at the Zanker Road Landfill, sending enormous clouds of white and brown smoke so voluminous they could be seen for miles by thousands of drivers on Interstate 880 and Highway 237.

The stubborn three-alarm blaze required 11 fire engines and 47 firefighters to continuously work the scene. But under a placid blue sky, with the water of the San Francisco Bay helplessly close by, the only accessible fire hydrant was half a mile down the road. That meant firefighters were forced to use precious time waiting as four 2,000-gallon water trucks made their way down to the hydrant and back up the hill.

The landfill closes at 3:45 p.m. Sundays, and there were workers onsite, said San Jose Fire Capt. Reggie Williams. But it took a passerby's phone call at 4:27 p.m. to alert firefighters about a column of smoke at the facility at 705 Los Esteros Road.

As the water trucks slowly trundled back and forth to the site, firefighters tried to extinguish the flames that continually popped up atop 30- to 40-foot-high mounds of tan bark.

According to the company's website, concrete, asphalt, wood waste, soil and yard waste are among the materials that are recycled there. Williams said that because the landfill turns raw wood of all kinds into wood chips, the potential fire danger is huge.

Wood chips, he said, "burn like candles," from the top down. Even though the fire at the upper crust of a pile is doused with water, the burning continues to move down into the center of the source material. Gusts of wind, at least 20 mph Sunday, hindered their efforts.

Williams said the landfill equipment also was on fire, and black smoke emanated from the machinery that he said likely held oil and other accelerants.

The cause of the fire remains under investigation; no injuries were reported.

Williams said the fire would likely take until Monday morning to extinguish.

Also at the scene was Richard Cristina, founder and president of the landfill, who watched helplessly from the top of the landfill.

He declined to speak to this newspaper. "I've got more important things to worry about," Cristina said.

San Jose fire officials said the dangerous blaze came on a day when at least 10 vegetation fires had erupted around the city amid Sunday's soaring temperatures and windy conditions.