I've used various solvents over he years, mostly gasoline or mineral spirits, depending on where or what I'm cleaning.
I keep an old mayonnaise jar full of gas in the shed for cleaning cage bearings and really dirty chains. When it gets really dirty, I soak up the gas with
old rags or paper and use it to start the trash barrel fire.

As far as someone dumping a bit of mineral spirits or oil, I think the likely hood of that doing major damage is fairly minimal in that oil floats on water, its not likely to soak into the ground, its more likely to get carried away in the next rain into the sewer or drainage. While certainly not ideal, most sewer treatment facilities separate out oil and grease in traps.

Years ago, local farmers dumped their old oil on roads and driveways to keep down dust. Many of those farms look like they're paved with asphalt these days. It was normal practice back then. I remember watching old timers with various contraptions they made to drizzle waste oil over their driveways.