Environment

Silicon Valley's latest high-tech gadgetry makes sewage water drinkable

Silicon Valley's latest high-t...
If California’s drought continues, residents may be drinking the recycled water from the Silicon Valley Advanced Water Purification Center in as little as two years
If California’s drought continues, residents may be drinking the recycled water from the Silicon Valley Advanced Water Purification Center in as little as two years
View 4 Images
If California’s drought continues, residents may be drinking the recycled water from the Silicon Valley Advanced Water Purification Center in as little as two years
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If California’s drought continues, residents may be drinking the recycled water from the Silicon Valley Advanced Water Purification Center in as little as two years
The process starts by feeding treated wastewater through small tubes in a microfiltration unit
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The process starts by feeding treated wastewater through small tubes in a microfiltration unit
Reverse osmosis sees water forced under high pressure through membranes with holes small enough for a water molecule to pass through and not much else
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Reverse osmosis sees water forced under high pressure through membranes with holes small enough for a water molecule to pass through and not much else
Like a powerful disinfectant, UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds
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Like a powerful disinfectant, UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds

Drinking recycled urine may be the stuff of Dune novels, and a drastic response to California’s ongoing drought. But officials in Santa Clara County in the heart of Silicon Valley are hoping its new high-tech purification plant will help residents get past the ick factor and eventually allow treated wastewater to flow through their faucets in a "toilet to tap" scenario. Opened in July, the US$72 million Silicon Valley Advanced Water Purification Center is the most advanced such plant in the US, and uses a multi-step system of microfiltration, reverse osmosis and ultraviolet rays to produce water of higher quality than typical drinking water.

According to Hossein Ashktorab, recycled water unit manager at the Santa Clara Valley Water District, the new plant daily produces 8 million gallons of water nearly as pure as distilled water. The advanced system is currently being used to improve the quality of the county’s recycling by treating water from older recycling systems, then blending it back with existing recycled water from the San Jose-Santa Clara Regional Wastewater Facility.

The process starts by feeding treated wastewater from the city of San Jose through small tubes in a microfiltration unit, made up of thousands of straw-like hollow fibers. The sides of the fibers are lined with extremely fine pores 0.1 micron in diameter, the equivalent of 1/300th the width of a human hair, which filter out solids, bacteria, protozoa and some viruses.

Reverse osmosis is the next step, forcing water under high pressure through membranes with holes small enough for a water molecule to pass through and not much else. Left behind are salts, viruses and such man-made contaminants as pharmaceuticals, personal care products and pesticides – a growing issue for water treatment facilities.

Like a powerful disinfectant, UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds
Like a powerful disinfectant, UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds

For the final step, the water flows through chambers that zap it with strong ultraviolet light. Like a powerful disinfectant, the UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds, in a process similar to the sterilization of medicine, food and fruit juices. In all, the process removes 99.99 percent of all pathogens.

The resulting purified water has a TDS (total dissolved solids) content of 40 parts per million. For comparisons sake, drinking water in the county averages 215 parts per million, while the recommended maximum contaminant limit is 500 parts per million. In other words, water from the advanced purification center is clean enough to drink, as one enthusiastic county official did at the plant’s unveiling.

For now, the water is going toward improving the quality of the county’s recycled water, used for irrigating crops and watering golf courses, parks, school lawns, street medians and business park landscaping. It’s also used to cool buildings and data centers, which will eventually include Apple’s new campus in Cupertino, opening in mid-2016. The tech giant is working closely with the water district to expand local recycled water programs, and is contributing $4.8 million toward the construction of a similar advanced recycled water facility near the coming campus.

With the potable quality of the water, the plan all along has been to introduce it into local taps by 2025. But as California’s drought continues, the project may get fast-tracked, and residents may be drinking the recycled water in as little as two years. In that scenario, the recycled water is pumped into aquifers to recharge groundwater, then pumped up, retreated and piped to local homes.

Source: Silicon Valley Advanced Water Purification Center

Drinking recycled urine may be the stuff of Dune novels, and a drastic response to California’s ongoing drought. But officials in Santa Clara County in the heart of Silicon Valley are hoping its new high-tech purification plant will help residents get past the ick factor and eventually allow treated wastewater to flow through their faucets in a "toilet to tap" scenario. Opened in July, the US$72 million Silicon Valley Advanced Water Purification Center is the most advanced such plant in the US, and uses a multi-step system of microfiltration, reverse osmosis and ultraviolet rays to produce water of higher quality than typical drinking water.

According to Hossein Ashktorab, recycled water unit manager at the Santa Clara Valley Water District, the new plant daily produces 8 million gallons of water nearly as pure as distilled water. The advanced system is currently being used to improve the quality of the county’s recycling by treating water from older recycling systems, then blending it back with existing recycled water from the San Jose-Santa Clara Regional Wastewater Facility.

The process starts by feeding treated wastewater from the city of San Jose through small tubes in a microfiltration unit, made up of thousands of straw-like hollow fibers. The sides of the fibers are lined with extremely fine pores 0.1 micron in diameter, the equivalent of 1/300th the width of a human hair, which filter out solids, bacteria, protozoa and some viruses.

Reverse osmosis is the next step, forcing water under high pressure through membranes with holes small enough for a water molecule to pass through and not much else. Left behind are salts, viruses and such man-made contaminants as pharmaceuticals, personal care products and pesticides – a growing issue for water treatment facilities.

Like a powerful disinfectant, UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds
Like a powerful disinfectant, UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds

For the final step, the water flows through chambers that zap it with strong ultraviolet light. Like a powerful disinfectant, the UV rays scramble the DNA (and thus neutralize) any remaining viruses and other trace organic compounds, in a process similar to the sterilization of medicine, food and fruit juices. In all, the process removes 99.99 percent of all pathogens.

The resulting purified water has a TDS (total dissolved solids) content of 40 parts per million. For comparisons sake, drinking water in the county averages 215 parts per million, while the recommended maximum contaminant limit is 500 parts per million. In other words, water from the advanced purification center is clean enough to drink, as one enthusiastic county official did at the plant’s unveiling.

For now, the water is going toward improving the quality of the county’s recycled water, used for irrigating crops and watering golf courses, parks, school lawns, street medians and business park landscaping. It’s also used to cool buildings and data centers, which will eventually include Apple’s new campus in Cupertino, opening in mid-2016. The tech giant is working closely with the water district to expand local recycled water programs, and is contributing $4.8 million toward the construction of a similar advanced recycled water facility near the coming campus.

With the potable quality of the water, the plan all along has been to introduce it into local taps by 2025. But as California’s drought continues, the project may get fast-tracked, and residents may be drinking the recycled water in as little as two years. In that scenario, the recycled water is pumped into aquifers to recharge groundwater, then pumped up, retreated and piped to local homes.

Source: Silicon Valley Advanced Water Purification Center

20 comments
Mel Tisdale
Water shortage is a problem and has been so for some time. When it comes to resource wars it will soon replace oil in some regions. Indeed it is already a cause of friction in some cases. (E.g. Egypt's opposition to Ethiopia's damming of the Blue Nile.) The last thing we need as a species is for climate change to make matters worse by creating droughts and changes to precipitation patterns. By making them more intense they are more likely to be shed into above ground features such as streams and rivers instead of having time to seep downwards and replenish much denuded aquifers. Projects such as this one will become the norm as the human population continues its inexorable growth and with its demand for water. As for the 'ick' factor, I imagine that will become irrelevant when the only option is to drink water from such sources. Anyway, isn't it a fact that every water molecule has been drunk before? Apple are to be commended for their support for this project. I hope that they can maintain their altruism by making any science the project reveals open-source and thus available to all.
EddieG
It surprises me to see that there is evidently public objection to a "closed" water system. In fact, I expected that by now, each home would have its own waste water processing station in the basement, next to the furnace. The water out of it would be cleaner than what I now get from the city. All "save the planet" aside, city water is getting dirtier and more expensive every year. In-home processing is the obvious solution.
owlbeyou
>a multi-step system of microfiltration, reverse osmosis and ultraviolet rays to produce water of higher quality than typical drinking water. But initially this water is to be used to irrigate grass and crops? There is no better filtration method that is more effective than Mother Nature's. As Mel says above, every molecule of the earth has been around the block a number of times. It is essential. Why then, aren't systems like this used to desalinate sea water, which is right there next to California? This is inevitable. Especially if high pressure fracturing continues unabated, and ends up contaminating underground water aquifers.
Mirmillion
Strangely, California has completely missed the idea of spreading volcanic ash on its irrigated fields. This would reduce water consumption by 50% while maintaining the same crop yield. Since agriculture uses 80% of the water in the system, you'd think they would have jumped on this idea...
Jay Finke
Sewage water drinkable, how the hell are you going to sell that ? label states.. may have contained turds and urine, but we filtered it real good, We promise !
Slowburn
Waste water treatment plants have been producing water at above drinking quality for decades.
Mel Tisdale
@ Jay Finke Name one astronaut who has suffered in any way from drinking processed human waste. Or do you think they manage to take all their drinking water up with them in plastic bottles?
Slowburn
@ Jay Finke Every drop of water you have ever drank has been through the bladder of some animal.
nutcase
Australians have been drinking sewerage ever since Anna Bligh famously took a sip on national television back in 2008
Pacific Oyster
My worry is the female hormones from birth control pills and females urine may not be filtered out resulting in men growing man-boobs, testicles become smaller, and sperm counts drop. This has already occurred in other parts of the world.