Wastewater is treated with a true septic tank (not the common Moroccan « lost well ») with horizontal filtering discharge to avoid contamination of the phreatic table. This water treatment meets European norms. Sawadi is one of the rare sites in Morocco that have achieved this level of respect of the environment. On 2016, we tried a natural filtration technique for the kitchen wastewater : we set up a banana circle. Banana trees consume and filter water. We hope having bananas quickly.