Motor oil cleanup?

[terracore]

Why would homeless people be dumping motor oil onto the ground? I could see if there was an illegal chop shop there or something how that could happen, but unless there was standing water and they were trying to kill mosquitoes I don't see a motivation. There are companies who test soil for contaminants including petroleum geared towards urban farmers, you might want to send a sample off to be tested. Maybe they were using the area as a toilet?