AEF greywater. For our final project we rebuilt a greywater system at the CSA, Arcata Educational Farm. Greywater consists of all used water produced at a particular site, except for water coming from the toilet, which is known as blackwater. When building a greywater system you first separate the greywater from the blackwater and send the greywater through a separate treatment system. Ideally, after the greywater passes through the purification process it will then be able to be reused. Greywater systems are an appropriate use of technology for many reasons. Some of them being: they reduce the use of fresh water, there is less stress on existing more conventional septic tanks, it is a highly effective purification process, and there is less chemical and energy use required. In our case the majority of water used on the farm is to water vegetables, herbs, flowers and fruits, and the source of greywater comes from the outdoor kitchen, used by the farmers and volunteers to cook and wash vegetables or dishes.