Increasingly, local governments, entrepreneurs and community activists are experimenting with composting.

The movement is inching forward in fits and starts, by entrepreneurs as well as by community activists and civic leaders, but the nation's trash disposal system lacks the ability to process food waste on a large scale. Food scraps are heavier than aluminum cans, making them more expensive to transport.

"It's been under the radar screen until now, and seen as a boutique, West Coast thing," said Jared Blumenthal, who oversees California as well as two other Western states and the Pacific for the Environmental Protection Agency. "But now everyone from Massachusetts to Minnesota has programs starting up, and pretty soon there will be a critical mass."

Environmentally minded city leaders have adopted "zero-waste" pledges, noting that traditional trash disposal not only wastes soil-enriching material but accelerates climate change.

Organic matter decomposing in landfills accounts for 16.2 percent of the nation's emissions of methane, a potent greenhouse gas. Vermont, Connecticut and Massachusetts are all phasing in bans on putting commercial food waste in landfills.

Although composting can work for large institutions ranging from hospitals to universities and hotels, which can save money by selling organic waste to third-party operators rather than paying to dump it in a landfill, it is more of a challenge on a smaller scale.

"This is an area that holds a lot of promise," said Harriet Tregonig, who heads the D.C. Office of Planning. "It's letting, really, nothing go to waste."

The United States is years away from achieving that vision. More than 170 communities across the country in 18 states have some sort of residential food scrap recycling program serving at least 2.3 million households, according to Rhodes Yepsen, who tracks the industry for the magazine BioCycle.

That's up from 20 programs in 2005 and does not include private programs.