Subscribe to our free daily newsletters
. Earth Science News .

Subscribe to our free daily newsletters

'Toilet to tap' gains appeal in drought-parched California
By Jocelyne ZABLIT
Los Angeles (AFP) Oct 29, 2015

The idea, for many, may be too hard to swallow.

But as California's historic drought drags on, experts and politicians are taking a serious look at "toilet to tap" options to guarantee long-term water supply.

The concept, which involves treating sewage water for human consumption, had until now failed to gain traction in the water-starved West Coast state largely due to the "yuck factor".

Few could stomach the idea that water coming out of a tap -- however purified -- was being flushed down a toilet just hours before.

Four consecutive years of drought, however, may force Californians to get over their squeamishness.

Snow melt from the Sierra Nevada, a key source of drinking water for the state, is virtually gone. Imported water from the Colorado river and groundwater are also in decline.

"Everyone is looking at wastewater recycling," said George Tchobanoglous, a water treatment expert and professor emeritus at the University of California, Davis.

"Right now, we discharge a lot of this treated wastewater into the ocean and we could certainly use it," he added. "And it's certainly feasible and cost effective in large metropolitan and coastal areas like California."

In a study published last year, Tchobanoglous estimated that by 2020, the concept known as potable reuse could yield more than 350 billion gallons per year, enough for more than eight million Californians, or roughly one-fifth of the state's projected population.

- Options running out -

The technology is already being used successfully in several communities in Texas, which has also faced a severe drought.

There, in what is known as direct potable reuse (DPR) or "toilet to tap," wastewater from toilets, washing machines, dishwashers and showers is turned into drinking water following a three-step purification process.

A similar plan for the city of San Diego, in California, never got off the ground more than a decade ago because of stiff opposition.

But now, as the Golden State struggles to meet mandatory water restrictions and as options run out, the project is back on the table.

Tchobanoglous said recent polls conducted for San Diego's Water Authority found that support for wastewater reuse now stands at 76 percent, compared to 23 percent in the early 1990s.

Advocates of water reuse point to California's Orange County purification plant, one of the oldest and largest in the world, as an example of the environmental and financial benefits of the technology.

The plant, which opened in 2008 during a previous drought, recently underwent a $143 million expansion and treats 100 million gallons a day, enough for 850,000 people. A final expansion is planned to bring capacity to 130 million gallons a day.

Another, smaller facility in Los Angeles county -- the West Basin treatment plant -- also recycles Californian sewer water, for potable and industrial use.

"Traditionally sewer water was viewed as a waste but now we see it as a valuable resource from which we can produce one of the best quality waters," said Shivaji Deshmukh, assistant general manager at the West Basin plant.

- NASA technology -

Neither facility feeds its purified water directly into the drinking supply, as is the case in Texas.

Instead, it is infiltrated into the groundwater aquifer, which provides an environmental buffer, before it is drawn back to the surface for drinking.

But the technology is the same as that applied in direct potable reuse.

First the water goes through micro-filtration to get rid of tiny organisms such as bacteria. Then it is purified further through reverse osmosis. Thirdly, ultra violet light zaps any remaining particles.

The result is a water as pure, if not more, than that on supermarket shelves.

NASA uses the same technology on board the International Space Station, where special equipment recovers the crew's urine, breath vapor and sweat to produce water for coffee or brushing teeth.

The water reuse camp has a financial argument on its side, too. "Bottled water is typically 10,000 times more of the cost of tap water without necessarily being better quality wise," said Ron Wildermuth, spokesman at West Basin.

"About a day or two ago this water was sewage. Now it's the best quality water I could drink," he said, showing off a sample, and gulping it down.

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only


Related Links
Water News - Science, Technology and Politics

Comment on this article via your Facebook, Yahoo, AOL, Hotmail login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Previous Report
Plant more trees to save Britain's rivers from climate change
Cardiff, UK (SPX) Oct 28, 2015
New research has prompted scientists to call on policymakers to plant more trees alongside upland rivers and streams, in an effort to save their habitats from the future harm of climate change. Published in the leading international journal Global Change Biology, experts from Cardiff University describe having discovered a previously unknown benefit of trees to the resilience of river ecosystems ... read more

Philippines' annual graveyard gatherings mix celebration with sadness

Using Google Street View to assess the engineering impact of natural disasters

Four castaways rescued off Mexico after month adrift

Third night in the cold for Afghan-Pakistan quake survivors

Holograms go mainstream, with future full of possibility

New HP Enterprise sees cloud ties with Amazon, others

U.S. Air Force awards Southwest Research Institute development contract

New System Giving SMAP Scientists the Speed They Need

The key to drilling wells with staying power in the developing world

'Toilet to tap' gains appeal in drought-parched California

Fiji leader says Pacific 'doomed' if climate talks fail

Beverly Hills nailed for not cutting back on water use

NASA finds mass gains of Antarctic Ice Sheet greater than losses

Mummified seals reveal ecological impact of ice change

Arctic attracting new military scrutiny

Fishing main hurdle to Antarctic marine reserves: Australia

Potato harvest reduced by half

EU lawmakers throw out GMO compromise law

Reducing the sweetness to survive

Farmers lose debt gamble in typhoon-plagued Philippines

Iraq PM declares emergency in areas hit by heavy rain

Cyclone heads for Yemen after injuring 200 islanders

Oman, Yemen warn coastal areas as severe cyclone approaches

'Extremely severe' cyclone heading for Yemen, Oman: UN

Africa's long-awaited intervention force finally stutters to life

South Sudan soldiers poach elephants in DR Congo

US charges Burkina man with $12m mosquito net fraud

Zimbabwe's Robert Mugabe wins Confucius Peace Prize

Divisive religious beliefs humanity's biggest challenge: Grayling

Predicting the human genome using evolution

Extinct ape species resets the scale on humans' ancestors

Research backs human role in extinction of mammoths, other mammals

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement