Grey Water is water coming from Sink, Shower, Bath and Washing machine. If you have the space to reuse this in your landscape, you can avoid the need for a sewage connection & septic tank. Earth Sheltered Design, with earth walls and attached greenhouses, is perfect for grey water re-use. Here is an overview of grey water systems made for simplicity, affordability and energy efficiency and how it can integrate with an earth sheltered home. ( The basis of these ideas are derived from the book ‘Create an Oasis with Grey Water’ from Art Ludwig and Oasis Design.