There was a Federal campground in the mountains near me that for over 50 years let all 79 campsites run their gray water on the ground until just recently. Guess what. It's as lush and green today as it was 50 years ago. And there were never any problems with bugs, bears, bees, soggy ground or lingering smells. No dead trees and no dead grass.
I realize this post may raise a stink (no pun intended) with some people but I just thought I would post about my experience at this super nice and popular campground. They did not have any dump stations at the time but when they finally installed one, dumping gray water on the ground was no longer allowed.