Need landfill question answered ASAP

I'm doing a little research for a presentation in my economics class and I'm trying to figure out how much the US spends on the cost of maintaining landfills every year. I've done search engine searches but I cannot find any totals. If anyone could help me locate that info it would be GREATLY appreciated. My tpic is going to be on other methods of recycling rather than dumping our "waste" products into landfills and polluting the environment. I've got all the info I need except the cost the US spends...just need an aproximate amount.
Thanks!!!!