So you are upset because the grass where they drained it might die? I don't get it...You're seriously asking why?? Crude is totally different than processed oil...plus, the acids and other chemical compounds that are introduced into the oil during the combustion process are pretty bad.
There was a pipeline in northern BC that broke a couple of years ago, spilling unprocessed oil onto the ground near a stream. My brother (a power engineer for an oil company) was in the area not long after, and where the raw oil had spilled, the plants were thriving. What happens when you pour used engine oil on plants?
Okay, I don't know how old you are, or what your education is, or your IQ. But look at it this way: If I told you the earth was round, and you believed the earth was flat even though I gave you proof, would you believe me? That's the same as what's happening here. I have studied this stuff, and I know how the water system works, and I gave you some educational information. It's up to you to believe it or dismiss it. But facts are facts.