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03.11.2011
Gray Water Gray Areas
Water recycling standards grow less murky.
Functional Pontos AquaCycle 2500 system by Hansgrohe.
Courtesy Hansgrohe

Protocols for gray water recycling could soon become much clearer for U.S. consumers. Working with product manufacturers who have found success in Europe and Asia, NSF International, the non-profit, non-governmental standard developer for product certification is likely to release new standards for gray water treatment systems sometime in the coming year.

The new standard, called NSF 350, would “establish minimum materials, design and construction, and performance requirements for onsite residential and commercial reuse treatment systems,” according to the organization’s web site. The standards would address residential systems that treat all wastewater from a home, in addition to those that treat only gray water from laundry or bathing.

That’s good news for companies like Hansgrohe, who is hoping to bring its Pontos AquaCycle 2500 system to the United States in the near future. Released last year in Europe, the system is designed to work mainly in 30 to 60-person residential buildings, offices, and hotels by treating about 500 gallons of gray water per day, as well as integrating rainwater and heat recovery systems. Though Pontos is in its second generation in Europe, “We have been hesitant to import it until we have a standard for the quality of the gray water,” said Lars Christensen, Hansgrohe’s director of product development. This hasn’t stopped the company from developing government-funded pilot projects in Virginia and California that will move forward with or without new standards.

Pontos AquaCycle

Pontos AquaCycle 2500 demonstration system.
 

With the NSF standard set to reach a ballot approval stage later this year and additional guidelines forthcoming from the International Code Council’s International Green Construction Code, the stage will be set for a new gray water treatment market in the U.S. But will the systems take off in this country? Without the high water costs experienced by Europeans, consumers are more likely to focus on hygiene than anything else.

“People are a little hesitant—what happens if kids drop toys in it?” said Christensen. Though standards are written based on averages, the technology must account for deviations (you never know what people might pour down their sink), and systems must be able to shut down if high levels of contamination are detected. Though the European Pontos system doesn’t use chemicals, the company will have to add chloride treatment systems to units stateside as an additional safeguard, but, “It will be less chloride than you have in drinking water in the U.S.,” said Christensen.

Other precautions, like purple dye and special signage to indicate treated gray water, will also likely be put into place. “Manufacturers of PVC pipes already have a purple pipe ready to go,” said Craig Selover director of plumbing product technology for Masco R&D. Purple water wouldn’t be used for irrigation, but it would help consumers feel safer about allowing gray water back into their homes or businesses. “The second issue is local health authorities becoming comfortable and being able to approve the systems,” said Selover.

According to a report issued last year by policy analysis organization Pacific Institute, approximately 50 percent of water used by U.S. homes could be used for irrigation and toilet flushing. Though national legislation regarding gray water reuse is unlikely, nearly 30 states already have regulations for treating gray water before reuse. In 2009, California changed its plumbing code to allow installation of simple laundry and single-fixture systems without a permit, thus enabling licensed plumbers to work on new or existing systems in the state.

While other states where water is scarce could follow suit, the cost of water more than anything will determine whether gray water reuse becomes a lifestyle norm in the states. “I’m reading more and more about water utilities looking at changing rate structures in order to encourage conservation,” said Selover. “At this point, to add cost to the plumbing system in a house isn’t desirable—people are more likely to select a granite countertop. But I think that’s something that’s evolving.”

Jennifer K. Gorsche