David Lee Hoffman has spent 50 years building a composting compound where waste – whether grey water from the kitchen or sanitation – is cleaned by worms, plants, and filters, then reused in the personal garden. Water flows through ponds, moats, and even a boat (which hides a 30-foot column that taps into groundwater), and everything is powered by solar, using a series of 12-volt pumps. Most of Hoffman’s system isn’t legal, according to his local county (Marin, California), and Hoffman has spent decades fighting the local government.

David Lee Hoffman's website: http://thelastresortlagunitas.org/