When I first started working on the family cars in my early teens 30+ years ago, we lived in a what was at the time a somewhat rural area (not so much anymore), and I would take our used oil back to the woods behind our house and dump it on the ground. I always dumped it on the same spot, about 10 feet off the walking trail. Three cars over the span of about 10 years, and it all got dumped there.
Some parts of those woods were sold and developed into houses a few years back, and while they were building I went back there to snap a few pictures because I didnt know how much they were going to tear out. The plant growth is and always was very dense in the area, with lots of weeds and saplings and honeysuckle bushes and whatever pretty much covering the entire ground.....and it still was, except the spot where I used to dump the oil. There was a good 10-15 foot diameter area right there, even 30+ years after having oil dumped there, where absolutely nothing was growing, just muddy-ish soil with a few leaves covering it, surrounded by lush greenery. Kind of a little anti-oasis, a big dead area surrounded by lush growth. I feel bad about causing that, but at the time I didnt know any better.