Waste Management Inc. recently estimated the $12.3 billion it gets for hauling trash to landfills may be worth more than $40 billion a year in energy.

The Houston-based company said that's the value of fuel and chemicals that could be taken from the 112 million tons of trash it collected last year if the entire waste stream was diverted from landfills, Carl Rush, senior vice president of Waste Management's Organic Growth unit, told Bloomberg News.

"We don't think the future, long term, is going to be continuing to put everything in the landfill," Rush told the news organization. "It's going...