The Green Wall is essential to the building’s self-supported water management system. To quality as a “living building,” a closed irrigation system was used – meaning it could not take in any water from City and waste could not be dumped into the City’s sewage. The Green Wall is the organic filter that cleans all of the grey water so it can be re-used. To do this, the wall of plants organically filters all of the building’s grey water through a process called phytoremediation, where wetland plants filter and recycle waste water through their roots and use contaminants of grey water, such as food particles, as nutrients for their growth.
The Green Wall’s watering schedule is determined by the Bertschi School’s use of grey water. Sensors are installed on the wall to determine the grey water levels available. When grey water levels are too low (such as during a school break), the sensors trigger the system to alternatively source water from a rainwater cistern.
In addition to creating a self-sustaining water management system, the indoor wall will also provide students as much clean oxygen as three fourteen foot-tall trees and will clean over 34 lbs of dust and harmful toxins in the air per year.