In short, graywater is the terminology for the diversion of water outflows from dish washing, laundry machines, showers and bathtubs to be used for irrigation of yards and our landscape. Graywater is different from Black Water. Black water is human and animal wastewater, and is under no circumstances fit for any type of irrigation in an urban environment.
There are many diverse opinions on graywater, favorable and non-favorable, and its place, use and value in our society. As Southern California grapples with the reality of water shortages and as climate change may decrease future snowfall in the Sierra Mountains, the use of safe and legal graywater systems reduce the demand for precious potable water, stretching our water resources while providing valuable irrigation to our yards and gardens.
Art Ludwig, the graywater guru, maintains an excellent and objective website detailing graywater systems and their use from a practical and common sense approach. The website will hopefully answer any questions on graywater systems and add much needed knowledge to a long neglected valuable potential source of water.
Graywater systems are legally subject to the Huntington Beach plumbing code, which reflects the CA plumbing code. The California Building Standards Commission (BSC) adopted new code language for the California Plumbing Code, Title 24, Part 5, Chapter 16A, Part I, that took effect August 4th, 2009. Installation of some graywater systems, provided 12 guidelines are followed, no longer requires a building permit. More detailed specifications and guidelines will soon be added, so please check back for more information!
Common Graywater mistakes and Preferred Practices
Illustration of graywater system, courtesy of greywater.com