The goal of the EcoBlock is to be net-zero water, capturing rain water for both potable and non-potable use. Depending on the density of the block and overall demand for water, there may be a need to at least occasionally supplement captured water with municipal water, but at least eliminate any stormwater discharge from the site. A combination of the following strategies will enable this achievement:
- Buildings will use low-flow fixtures to minimize water usage, and be built with dual piping systems to allow rain water and waste water to be appropriately treated for reuse as either potable or non-potable water, using separate storage areas for each. Composting toilets may also be used to reduce demand for water.
- All waste water, including black water and grey water, will be captured and appropriately treated, and reused only for non-potable applications.
- Green roofs will capture and store rain water, and provide additional insulation for buildings to reduce heating and cooling costs. Excess water will be stored in rain barrels and underground cisterns. A multi-stage filtering system includes screens and filters to capture large debris, activated carbon, and sediment filtration. Potable water will be sterilized using micro/nano-filtration, reverse osmosis and ultraviolet light.
- Bioswales, rain gardens and bioretention ponds will be used to capture and retain storm water, allowing water to infiltrate into the ground or retention basins.
- Permeable pavement will be used throughout the block, including sidewalks, courtyards and driveways. This may include both porous pavement, interlocking pavers, gravel and other pervious surfaces. Water can either be absorbed back into the earth or directed into storage tanks.