Water use has been growing at more than twice the rate of population increase over the last century. As water demand approaches (and in some instances exceeds) the available water supply it becomes apparent that the current practices of diversion, consumption, use and disposal are depletive, destructive and inadequate. To combat this issue, many buildings have opted to provide on-site water resource management systems to help reduce the amount of potable water being used. Water fit for purpose is the new mantra for the water industry where all sources are considered and technologies from natural systems to membrane bioreactors (MBRs) are selected using triple bottom line principles. (via)
Note: learn what membrane bioreactors are.