That's a great question, one I'm going to have an insufficient answer to.
The only ones that really are under development with respect to municipal solid waste are technologies we've been talking about for decades: gasification, pyrolysis, plasma arc. Those are all technologies that are in existence today; they're just not being used on a commercial scale for municipal solid waste. In the next five to ten years there will, I think, be some facilities that are using one of those three types of technology to handle municipal solid waste on a commercial scale.
Covanta Energy, which is a large developer and operator of waste energy facilities in North America—or actually, around the world—has a demonstration gasification unit at one of their facilities in the United States. They're actively marketing that type of technology. I would expect that we'd see one of those types of units in the next five to ten years, certainly.
Whether it's going to be market-shaking in terms of outperforming combustion-based technologies, I don't have any way to predict; I don't have an opinion on that. But I think we will see one of those other types of technologies get a foothold, and then we'll be able to analyze the results.