'Folks like Kris are part of a grass-roots movement that's making America greener right now,' Obama concluded. 'He's way ahead of Washington.' Oh, how long ago that day seemed last month when I drove my diesel-powered 2002 Volkswagen into the Conserv Fuel station for a fill-up. I bought the little green Bug four years ago to run exclusively on biodiesel. The fuel, made from vegetable oil or animal fat, works in diesel engines just as well as diesel made from petroleum, and it requires no modifications to the machine. I'd been a regular at Conserv Fuel ever since I bought the car, but on that June day, the station attendant tried to head me off: 'No more! No more!' he shouted, waving his hands. When I got closer, I saw what the fuss was about: The biodiesel pump had a shiny new sign on it: 'Diesel #2.' The man pointed at a letter taped to the inside of the window. It said that Conserv Fuel would no longer sell the sweet-smelling, cleaner-burning fuel on which I'd come to depend. My local fueling station's flirtation with biodiesel was over. I put enough stinky fossil-fuel diesel in my tank to get home and drove off, shamefully chugging soot all the way. Conserv Fuel's abandonment of biodiesel grew out of a June decision by the State Water Resources Control Board to begin enforcing laws against storing biodiesel underground. As commercial fueling stations have no economical way to hold fuel in tanks on the surface, the ruling forced most of the state's retail biodiesel pumps to switch to petroleum or close. I'm all for caution when it comes to storing chemicals in the ground, and California's regulators want to avoid another underground-storage fiasco like the one in which the gasoline additive MTBE migrated into drinking water. What's better for the air isn't necessarily better for the ground, which is why green fuels get no special treatment. 'Everything that's going to be stored underground has to be tested by an independent authority,' water board spokesman William Rukeyser says. The problem is that getting a new fuel tested can take three years. The board's concerns would make sense were biodiesel a new, foreign substance. But it's not. Several studies have found that biodiesel in its pure form is less toxic than maple syrup; it degrades faster than sugar. The U.S. Environmental Protection Agency found its exhaust does no harm to human health. The water board has said it is less worried about the fuel itself than about substances added to biodiesel. One agency official claimed biodiesel comes in as many as 1.5 million different formulations. That's a wild exaggeration -- by law every batch of fuel conforms to a chemical standard. But it's true that some manufacturers add preservatives to the fuel to extend shelf life. Others add a small amount of petroleum so that vendors can take advantage of a tax incentive that the federal government grants to sales of blended fuels. But none of those additives is necessary, says Eric Bowen, chairman of the California Biodiesel Alliance. 'Only if it's traveling over long distances and in storage for a long time does biodiesel begin to degrade,' he says. 'There's no practical reason for adding anything to local, sustainable biodiesel.' Regulators have already made a temporary exemption for the underground storage of blends up to 20 percent biodiesel and 80 percent petroleum, just to keep the industry afloat until independent certification comes through. Why not make the same allowance for 100 percent home-grown biodiesel from local producers? Such a ruling could help foster the state's hoped-for green economy by encouraging ever-more sustainable biofuels. It could also help us biodiesel users assure our cynical friends that we aren't destroying rain forests to fuel our cars. In the meantime, many of us who wanted to reduce the environmental impact of our driving remain helplessly shackled to petroleum, our green dreams thwarted by California's inconsistent energy policy. State agencies pass laws to clean up the air and pledge to address climate change, then allow industry pressure to kill the electric car and throw up obstacles to alternative fuels. It makes you wonder, were Obama campaigning today, where in California he'd deliver his defiant speech on energy policy. It seems unlikely, right now, that he'd pick California at all. Lewis is a Los Angeles journalist who writes about technology and environmental issues. She is a contributing editor to High Country News. 