Since the early 1990's federal funds have been used to subsidize contaminated soil remediation and brownfield restoration. I don't doubt that any soil that had been contaminated (even if it had occurred many decades earlier) by petroleum or other chemicals or other forms of industrial waste would have had to have been professionally removed with the disposal fully documented. I also know (from what the companies that I've worked for during the past quarter century) that federal funds would have covered nearly the entirety of the costs (depending on the situation, 85%-95% if documented and supervised correctly).
I know of a handful of such projects within the northeast and numerous other projects throughout the rust belt where anywhere from $10mm to $45mm (per project) was funded by federal grants through DEEP. If the cost of doing this for the site work at Rentschler Field wasn't almost fully subsidized, someone didn't do their job (which is entirely possible).