Battling over french fry grease

A few years ago, drums of used french fry grease were only of interest to a small network of underground biofuel brewers, who would use the slimy oil to power their souped-up antique Mercedes.

Now, restaurants from Berkeley, California, to Sedgwick, Kansas, are reporting thefts of old cooking oil worth thousands of dollars by rustlers who are refining it into barrels of biofuel in backyard stills.

"It's like a war zone going on right now over grease," said David Levenson, who owns a grease hauling business in San Francisco's Mission District. "We're seeing more and more people stealing grease because it lets them stay away from the pump, but it's hurting our bottom line."

Grease is transformed into fuel through a chemical process called transesterification, which removes glycerine and adds methanol to the oil, leaving a thinner product that can power a diesel engine. Biodiesel can also be blended with petroleum diesel, and blends of the alternative fuel are now sold at 1,400 gas stations across the country.

But as the price of diesel shoots up, so, too, does the value of grease.

"Restaurants and staff are no longer looking at this material as trash, they're looking at is as something that's about to go into city vehicles," said Karri Ving, who runs the city's new waste cooking oil collection program. "Unless you lock down every trash can, thefts are going to happen."

Drivers for Blue Sky Bio-Fuels, a grease hauler that also manufactures biodiesel for San Francisco's municipal program, often find the 300-gallon dumpster they store outside the Oakland Coliseum nearly dry, despite the dozens of concessions stands that regularly dump their oil there. Losses at that one site alone have cost the company $3,700 in foregone oil revenues in the last year, said Wesley Caddell, the Oakland firm's business developer.