As governments across the country enter the triennial building code cycle, including adopting the 2015 International Plumbing Code, it is key that they not ban greywater use.

Codes are usually adopted by local government legislative bodies, often with the advice of boards comprised of retired or senior members of local trades (e.g., the Plumbing Board) many of whom may not be conversant in sustainability and new innovations in green building. Many, if not nearly all, local governments alter and amend national codes for their own purposes. A prime example is that many local governments adopted the 2012 International Plumbing Code or 2012 National Standard Plumbing Code amending the national standard codes to remove the provisions that authorized the reuse of greywater (i.e., most by simply deleting 2012 IPC Chapter 13 Gray Water Recycling System).   

Water, including rain (i.e., storm water) other than toilet waste, draining from a building is greywater and suitable for reuse as nonpotable water. Reusing greywater serves multiple purposes: it reduces the amount of potable water needed to supply a building, it reduces the amount of wastewater entering sewer or septic systems, and it provides an alternative for storm water management, etc.

Plumbing codes now specify how systems must be designed, installed, and maintained to prevent cross contamination of drinking water and nonpotable water. That toilets are flushed and lawns are watered with drinking water is crazy.

But clinging to the past, many local governments today ban greywater. In 2010 the Maryland legislature was forced to enact a state law mandating “a county may not adopt or enforce a provision of a local plumbing code that prohibits a greywater recycling system.”

Banning greywater use is silly because arguably, all water on the planet has been reused. Earth came into being with all of its water about 4.4 billion years ago. No water has been added or subtracted. Scientists tell us that over the last 50,000 years over 100 billion people have inhabited the Earth and let’s assume a conservative 30 year life span with a typical person needing to consume 3 quarts of water a day (although today the average American uses 1.9 gallons a day). So that is more than 858 trillion gallons of water consumed by people. And that doesn’t include animals that outnumber people by over 1000 to 1. An elephant may consume 40 gallons a day. Paleontologists tell us the bathtub size depression found south of La Junta, Colorado “is the first recognized evidence of urination by dinosaurs” proving that about 150 million years ago a dinosaur stopped and peed 300 gallons. And there were millions of dinosaurs, all drinking water and peeing. So, easily creatures have had inside their kidneys and peed thousands of times all the potable water available on the planet. At this point it is all greywater.  

Drinking water is among the most pressing environmental issues facing the planet. But because potable water is so cheap in most Western countries, it is given short shrift in many sustainability efforts. 

In a potable water constrained world, local governments should not delete 2015 IPC Chapter 13 Nonpotable Water Systems when adopting plumbing codes this year.