There’s way too much hidden plumbing for that. I wouldn’t trust that the piss is actually staying at the grave. It should just be a gravel pit with PVC pipe that goes straight down into the ground, with a funnel on the end for people to piss into. Could even have two different height funnels (one near the ground for the squatters, and one raised a few feet for the standers) so it is fully inclusive. Anything more elaborate would be a waste of taxpayer money.