Easy bailout of the land owner's cleanup obligations. Good deal if you can find the right sucker.
Most of these sites are abandoned or underutilized and have become a blight on nearby communities. They include gas stations, metal platers, old gas works, paint manufacturers, drycleaners, print shops, chemical storage and steel fabricators.
It's in the economic interest of the local government and state to remediate the sites and put them back into productive uses, such as commercial districts and business parks.
If the landowner is still viable, the city and state will work to recover the cleanup costs, but that's not typical for most of these sites.