I have thought the same thing about digging up & scrapping out all the old stuff dumped into land fills. while a good bit will be there most of the stuff would only be last couple decades at best worth attempting. scrap prices are way down now. The land fill gases though is great idea. I work for a directional drilling company (American Augers Inc.), older land fills can be drilled into using directional drills running perf pipe can shove in a lot of pipe, use vacuum to suck out the gas, clean through water filters the gas to de-toxify it & pump or burn in generation plant... that is only real economical way to go about it if the pipe was not laid prior to topping, which is now mandated to be done by feds.
Mark
