unicoi has some sewer sites and the newest park, Don Carter SP has grey water dump at each site. It's basically a french drain with an aluminum bucket dug in the ground with holes drilled in it, and charcoal in it to stop any odors. They tell you to just leave your valve open so it can drain freely. i would not do a full tank drain due to the sheer volume that comes out so just make sure your tank is empty before checking into your site. Great idea that I wish all Ga SP would implement. Not costly and simple to do, but so far the powers that be are silent.