environmental liability is pretty complicated. every previous owner of a contaminated parcel can be held liable for injury and cleanup costs. the result is that contaminated land is virtually useless to wealthy developers.

the way around it is to get a letter form the epa saying that the contamination is remediated. it's a matter of public record so if one was issued for riverside park, it should be around still. the letters are granted for a specific purpose. the level of remediation required for a parking deck may differ significantly than what is required for a dirt bike course.

often times, the treatment is pretty minor, strip the top few feet, put down a liner that exists mainly to warn off future diggers and cover with clean soil. other times, extensive pump and treat systems are required or even very deep excavations [[like the uniroyal cleanup)