I once tried a camp along a Murray River. Not my usual camping place as I prefer smaller, cleaner rivers. Got there late to find the place packed. Found a spot and set up. Got up in the morning to find more toilet tents than caravans/campers. Some had a chemical toilet for no1 and a pit toilet for no2. I wondered why if you would s**t in a pi you could p**s in a pit.. Some of these tents were as close to the waters edge by 15mtr horizontally. They dug a hole maybe 250-300mm deep, placed a garbage bin liner in the hole, and put the seat over the hole. When they left they take the seat, fold the plastic bag over the top and cover with dirt. Some might say what's the problem. I walked back 35-40mtrs to dig a hole with a post hole digger. 1st hole hit plastic, 2nd hole hit plastic, 3rd hole plastic. On the 4th hole, dug it 800mm with no plastic. Did some test digging to see how much plastic was there. More than not every hole I dug plastic came up. Plastic as low as 75mm under the ground and as close to the water as 10mtrs. The whole area must have a layer of s**t bags under the surface. So have a think next time when your camped on a nice clean campsite. Is it really . And this was only 1 campsite along that river.