Stone brewed a beer with reclaimed water

At a March 16th event, Stone Brewing served pours of a beer called Full Circle, a pale ale made with dark malts, all New Zealand hops, and reclaimed water — that is, reclaimed from San Diego's sewer system by the North City water reclamation plant in Miramar.

The plant primarily captures waters that would otherwise be dumped in the ocean, and cleans up to 30 million gallons per day to feed into the city's non-potable tertiary water line (the purple pipes), used only for irrigation and industrial purposes in Mira Mesa and surrounding communities.

However, since 2011, the plant also features a demonstration plant for its Pure Water program, which uses upgraded technology to further clean the water, to the point it's significantly cleaner than tap water.

"It's actually a lot better quality in terms of salts, or any other dissolved solids that might be in the water," notes Tim Suydam, Stone's senior water operations manager, whose team monitors the brewery's water supply. "The TDS [total dissolved solids] was less than 100 parts per million," he adds. "Typically we get between 300 and 600 out of the tap."

The city estimates 90 percent of our water supply comes from outside sources, meaning it passes through other cities before reaching ours and must be treated with chemicals before it's deemed safe enough to drink. Stone, and many other breweries, typically make an effort to further strip that water of undesirable particles.

"For the brew for the event," Suydam points out, "we added minerals to match our brewing water quality requirements, because it was so clean."

Stone chief operations officer Pat Tiernan poured Full Circle beer at the event, along with mayor Kevin Faulconer. He notes that, as the recent drought wore on, the total dissolved solids counts Stone was seeing from city water had been steadily rising. That's why the Stone team was excited to accept when the city asked them to make a demonstration beer. "We did it to express our support," Tiernan says.

Each day, the pure-water demonstration plant recycles one million gallons of water. While a minuscule amount is served to guests taking a tour of the North City plant, most of it winds up going into those purple pipes, along with the rest of the tertiary supply.

However, Brent Eidson, deputy director of external affairs for the city, points out this demonstration plant was set up to demonstrate to state regulators that the technology succeeded in producing water pure enough to drink. Having done so, the technology will be put to use for real.

"What's kind of exciting, and why we're doing this now with Stone," Eidson says, "is we're now in design for the first phase of actual facilities that will be delivering water by 2021." A larger purification plant will be built next to the North City facility, capable of reclaiming 30 million gallons of water per day. That water won't go to the purple pipes but will be mixed into local supply, headed for the taps.