Graywater — domestic wastewater not originated from toilets — constitutes up to 70 percent of total indoor wastewater generation, according to a recent Water Environmental Federation (WEF) report. Widespread nonpotable reuse of graywater could potentially lead to a significant reduction in water demand, and over 8 million people across the United States are already using graywater for landscape irrigation and other outdoor uses, according to the White Paper On Graywater by Bahman Sheikh.
Yet most of the graywater reuse currently taking place is illegal.
"Millions of people are using graywater, but most of them don't have the permits their state requires because the permitting rules are so stringent that no one can comply," said Charles Graf, who works for the Water Quality Division at the Arizona Department of Environmental Quality (ADEQ). "Strict permit regulations are just doomed to fail, because when the rules are too hard to follow, people will just do it illegally."
Currently, permitting for onsite graywater (alternatively spelled greywater, grey water, gray water) collection and/or reuse is required in 30 states. Permit requirements aren't standardized across the country, and individual state requirements can often be confusing and difficult to follow, reports WEF.
"The often cumbersome permitting process for graywater reuse and the lack of public education resources have adversely affected the overall acceptance and adoption of onsite graywater treatment and reuse, as well as development of standardized technological approaches in the United States," WEF wrote in their report, Regulatory Incentives and Impediments for Onsite Graywater Reuse in the United States.
Graf has first-hand experience with the downsides of stringent graywater reuse regulations. Prior to 2001, Arizona law required graywater users interested in subsurface reuse to obtain a disposal permit, engineering review, and a septic tank/leach field, while those interested in surface reuse had to obtain a reuse permit, chlorinate, monitor, and report on the impacts of their graywater reuse. Despite an estimated 200,000 to 300,000 residential graywater users in Arizona, the ADEQ only ever issued two permits.
"When we found out how many people were doing it without a permit, we figured we needed to take a different approach," said Graf.
Arizona became the first state in the U.S. to take a nonpermit, educational approach to residential graywater reuse. Home graywater use is now permitted without registering or submitting an application to ADEQ as long as best management practices are followed, graywater flow is less than 400 gallons per day, and use is limited to irrigation or composting for single-family homes. Graywater use is only investigated if a complaint is made. Graf feels this approach has been successful, as the ADEQ has received very few complaints in the 13 years since it has been implemented.
"We basically legitimized what people were already doing. Everyone thinks this is a forward-looking approach," he said. "Almost immediately after enacting the rule we got calls from other states."
New Mexico, Montana, and Texas now have similar nonpermit graywater programs.
But the state-to-state similarities between graywater permitting requirements stop there. According to the WEF report, the biggest factor limiting graywater in the United States is the inconsistency of regulations throughout the country.
Some states, like California, have permits for some types of graywater use, but not for others. In 2009, California made a code change allowing "laundry-to-landscape" graywater use without a permit. A typical laundry-to-landscape graywater system works by using the drain hose from a washing machine attached to a system of pipes or hoses set up to irrigate a lawn or garden. Most systems are installed by homeowners themselves or with the help of a landscaper.
Systems that alter the plumbing, include a pump, or divert water from showers, sinks, or baths still require a permit and home inspection in California. Obtaining a permit is often challenging, as not all city officials are familiar with graywater reuse regulations, and there can be a lot of red tape, said Laura Allen, founder of nonprofit organization Greywater Action.
"When people go to their city and explain what they want to do, they get a lot of questions," said Allen. "Many people don't know what graywater is, and they think it is illegal even with a permit."
Greywater Action's goal is to educate California residents and city officials on the process of graywater system design and construction, and on the importance of water reuse. Allen and her team work with city officials and residents to educate them about what types of graywater reuse are legal and safe. In addition to offering programs on how to install the legal laundry-to-landscape graywater systems, Allen's organization has also created a checklist that residents can use to take the right steps when trying to obtain a permit for other types of graywater reuse from their city governments.
Despite the steps her organization has taken, Allen believes that graywater reuse will never be fully utilized in California until regulations change to allow simple graywater irrigation systems without a permit, like in Arizona.
"There is a huge range of reasons that people don't want an inspector coming to their house, and because of that, at least 50 percent won't get a permit," said Allen. "The problem with that is if they aren't getting a permit they ignore all the safety and health best practices, and graywater reuse then becomes less safe."
In some states, graywater reuse is a controversial topic. Wyoming policy makers have gone back and forth on graywater reuse regulations.
The state previously had a graywater program modeled after Arizona's nonpermit approach, but recently that policy was altered, says Hannes Stueckler, from the Wyoming Department of Environmental Quality (WDEQ).
"The policy was in place for about two years, and it was very well received by residents," said Stueckler. "Then it got rescinded, and now we don't know what the regulations will be. Right now they are being rewritten."
Resistance to graywater reuse mostly stems from public health concerns, said Stueckler.
"Some feel that graywater is a form of sewage because it has pathogens in it, and human contact needs to be avoided," he explained.
Graywater contains what is known as indicator bacteria, which are types of bacteria used to detect and estimate the level of fecal contamination of water.
"These organisms by themselves aren't dangerous, but they indicate there is potential for bacteria to be there," said Stueckler. "But thus far there is no medical record of anyone ever getting sick because of graywater exposure. It's potential to be a public health hazard is pretty minimal."
According to the WEF report, water quality of individual graywater streams varies depending on its origins. Kitchen graywater, which is allowed in some states but not in all, is more contaminated compared to other nonkitchen graywater streams, containing more solids, oil, and grease; organics; microorganisms; and surfactant.
ADEQ's Graf feels that the safety of graywater reuse depends on the programs that manage it.
"There isn't zero percent risk, but like anything else we regulate, you minimize the risk with best management practices. We have tried to do with our nonpermitting system," he said.
Regardless of how individual states decide to regulate graywater, the practice is worth considering in the face of water scarcity, especially in states suffering from drought, said Allen, of Greywater Action.
"It just makes more environmental sense to reuse that water from your shower, sink, or washing machine," she said. "Why would you just throw it away? It is as important to recycle water as it is to recycle everything else."
Image credit: "Grey Water for my Flowers," © 2009 daveiam, used under an Attribution-ShareAlike 2.0 Generic license: https://creativecommons.org/licenses/by-sa/2.0/