People have been draining their gray water in the forest for years and I've never seen any evidence of it.
Exactly..Just think of an outfitters hunting camp..8 plus people plus guides and crew in one place washing dishes/cooking and relieving them selves without holding tanks..It all goes on the ground but more responsibly than the average camper..
What irritates me more than anything, is a short hike from the outhouse and you see piles of toilet paper without any effort to put it in a hole and cover it..
I don't dump my grey water unless I have to,that's what the holding tanks are for,not for being to lazy to hit a dump station instead..LOL