You do have a tough place there Charlie,First off I would probably do a soil sample first,being a old landfill,your ph will probably be through the roof,thats what I would do first,determine your soil quality,lime fertilize if needed,then plan on what you want to do.I would warn you though I once attempted to work an area of ground that was once a old dump area,and spent more money fixin equipment than I could imagine due to old peices of metal,tree stumps,concrete blocks ect..