Toilet to tap? Some in drought-prone California say it’s time

Devika G. Bansal, Bay Area News Group, 7/5/17

As drought and water shortages become California’s new normal, more and more of the water that washes down drains and flushes down toilets is being cleaned and recycled for outdoor irrigation.

But some public officials, taking cues from countries where water scarcity is a fact of life, want to take it further and make treated wastewater available for much more — even drinking.

“This is a potential new source of water for California,” said former Assemblyman Rich Gordon. “We need to find water where we can.”

In a sense, the water we drink today has been recycling since the beginning of time, thanks to the natural water cycle. Recycling wastewater in a treatment plant simply speeds up that process, and experts say the source of water is not as important as its quality.

“There are places in the world where people are drinking recycled water,” Gordon said. “In fact, it’s the water our astronauts drink at the space station.”

Water recycling is more the norm in countries like Singapore, Israel, Saudi Arabia and Australia, all of which have long had water shortages. Israel reclaims about 80 percent of its wastewater, while Singapore reclaims almost 100 percent. The reclaimed water is extensively used to irrigate agricultural lands and recharge aquifers in Israel, while most of Singapore’s water is used for industrial purposes.

And because sending loads of water into space wasn’t an option, NASA scientists installed the Environmental Control and Life Support System at the International Space Station so astronauts could safely drink recycled water.

A poll from last year revealed that 83 percent of Californians are “ready to use” recycled water “in their everyday lives.” And a spot survey in downtown San Jose supported the poll’s findings.

“I would drink it,” said Ing-Shien Wu, a Mountain View resident who works in San Jose. “Yeah, it sounds weird. Yes, it was once your waste. But in some sense we are recycling the water anyway. It goes out and it gets evaporated and comes back as rain. So if they have something that’s comparable, sure. Why not?”

Right now, as much as 5 percent of Santa Clara County’s water supply comes from recycled water, all of which is currently designated for non-potable uses such as irrigation for landscaping and golf courses.

The bulk of that recycling happens at four wastewater treatment plants in the county, whose primary job is to remove all the junk from water before it is flushed into San Francisco Bay. But a small portion of the cleaned wastewater gets a second life — it goes through a few more steps that progressively remove the tiniest of pathogens and harmful chemicals.

Making that water fit for public consumption requires more quality checks and more filtering — all of which shakes out at the Silicon Valley Advanced Water Purification Center, in San Jose at the base of the bay, along Zanker Road.

Since its opening in 2014, the plant has been producing about 8 million gallons of near-potable water every day. That’s enough to maintain about 10 Palm Springs golf courses for a day.

“We go above and beyond conventional treatments,” said Paolo Baltar, a civil engineer at the Santa Clara Valley Water District.

The Purification Center pumps partially cleaned water from the nearby San Jose Regional Wastewater Facility through thousands of tiny tubes to get rid of pathogens in a process called microfiltration. The water next flows through reverse osmosis membranes to remove salts, and it finally gets bombarded with intense ultraviolet light to break down any remaining chemicals or pathogens. The water quality is monitored constantly.

But before anyone can drink the purified water, it must go through one final cleaning: It is blitzed with hydrogen peroxide to kill any remaining pathogens.

What Santa Clara County is doing is nothing new — Orange County uses the same process to reclaim wastewater to pad its drinking water supply indirectly by pumping the purified water into the ground.

That’s something the Santa Clara Valley Water District hopes to implement in the near future, said Nai Hsueh, a board member of the water agency.

“At this point, the purification center is experimental,” Hsueh said. “But we are aggressively pursuing plans to produce purified water for potable use.”

The agency has two more advanced water purification projects being planned — one a new plant in Sunnyvale, close to the Donald Summers Water Pollution Control Plant, as well as an expansion of the existing Zanker Road plant.

There is statewide interest in directly mixing the purified water into drinking water supplies, but the “ick” factor has been a barrier.

Terms such as “treated wastewater” and “toilet to tap” don’t exactly help that perception. Singapore, for example, chose the term “NEWater” for its recycled water. The Santa Clara Valley Water District calls it “purified water.”

A brewery in Half Moon Bay has a more creative approach: It periodically makes beer out of recycled wastewater. The brewing process is exactly the same, although the brewery isn’t allowed to sell it yet.

“We’re doing this to get people to be aware that this is water and we should be making use of these technologies that work,” said Lenny Mendonca, owner of the Half Moon Bay Brewing Company.

To address the public perception issue, former Assemblyman Gordon was able to push Assembly Bill 2022 through the Legislature last year. It enables water agencies in the state to distribute bottles of advanced purified recycled water for educational purposes.

“The idea behind it was for people to get used to the concept that we can actually purify water to drinking standards,” Gordon said.

The new law went into effect in January. But the Santa Clara Valley Water District doesn’t seem to have any plans to move forward with the bottling process. In part, this is because the law requires having a bottled water facility approved by the U.S. Food and Drug Administation on site, Baltar said.

The Purification Center on Zanker Road does its own outreach through public tours for people to see and understand the water’s journey from being slightly muddied to becoming crystal clear. What the tours don’t do, however, is have people taste the water for themselves. But regardless, Hsueh said, the tours are useful to convince people of the high quality of the recycled water.

“When people see it,” said Garth Hall, a deputy operating officer at the water district, “they see it’s just water.”

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