Beyond the Yuck Factor: Cities Turn to ‘Extreme’ Water Recycling

Photo: A rooftop wetland on the Salesforce Transit Center in San Francisco filters wastewater from sinks and showers for reuse.

San Francisco is at the forefront of a movement to recycle wastewater from commercial buildings, homes, and neighborhoods and use it for toilets and landscaping. This decentralized approach, proponents say, will drive down demand in an era of increasing water scarcity.

In downtown San Francisco, in a cavernous garage that was once a Honda dealership, a gleaming white-and-blue appliance about the size of a commercial refrigerator is being prepared for transport to a hotel in Los Angeles.

There, this unit, called a OneWater System, will be installed in the basement, where its collection of pipes will take in much of the hotel’s graywater — from sinks, showers, and laundry. The system will clean the water with membrane filtration, ultraviolet light, and chlorine, and then send it back upstairs to be used again for nonpotable uses.

And again. And again.

“There is no reason to only use water once,” said Peter Fiske, the executive director of the National Alliance for Water Innovation, a division of the Lawrence Berkeley National Laboratory, in Berkeley. Just as natural systems use and reuse water repeatedly in a cycle driven by the sun, he said, “we now have technologies to enable us to process and reuse water over and over, at the scale of a city, a campus, and even an individual home.”

While centralized water reuse […]

Full article: e360.yale.edu