How Desalination Tech Could Save California
California is suffering from drought – and they’re just the tip of the no-iceberg. Areas across America and the rest of the world are facing the same problems.. Could desalination tech help?
71% of the Earth’s surface is water, 96% of it in our oceans. That’s not even counting all the water in the atmosphere, glaciers, and global water tables. There’s so much water – but countries including Egypt, Syria, and Somalia are at extreme risk from water shortages.
California’s drought has been going for four years now. William Shatner thinks pipelines running from Seattle will work, at a cost of $30 billion. But could the answer instead be on California’s doorstep?
Water, Water, Everywhere – And Not a Drop to Drink
The drought is threatening California’s 38.8 million residents, so much so that in January, Governor Jerry Brown declared a State of Emergency. He claimed only “unprecedented actions” can solve the situation, and made conservation mandatory. Droughts are nothing new to the Orange County, but this is a record-breaking ecologic catastrophe, and serves as a warning to further potential victims, notably Texas. Tom Pankratz, a desalination consultant, tells Quartz:
“When it comes to increasing water supplies, you have four options: Increase your amount of reuse, increase storage, conserve it, or turn to a new source.”
Desalination could be this new source, and is among the emerging technologies changing the world . It’s making seawater drinkable. Scale it up and the process could even give us a way to survive in underwater cities .
Over 17,000 plants across 150 countries already provide seawater as drinking water to hundreds of millions of people. That the same service could work in California isn’t a mere pipedream.
How Does Desalination Work?
Earlier distillation technology was largely focused on preparing ships for long voyages. In 1684, famous diarist and Secretary to the Admiralty Commission, Samuel Pepys wrote to Captain Gifford on behalf of King Charles II:
“Whereas a Proposal has been made to Us of an Engine to be fixed in one of Our Ships for the making an Experiment of producing fresh water (at Sea) out of Salt…”
In the USA, a technical report was presented by Secretary of State, Thomas Jefferson in 1791 describing a simple distillation process’ results, with information intended to be reproduced on the back of all papers stored on marine vessels in case of emergency.
Very simply, seawater is pumped through intake pipes, with filters used to limit marine life casualties (and stop larger debris clogging the passages). The water is then forced through a pre-treatment process that removes viruses, silt, and other waste, before going through reverse osmosis. This is the crucial step of the process. Powerful pumps force seawater through a semi-permeable membrane which allows through only small particles like water molecules, blocking larger impurities. A carbon filter can also be used after the reverse osmosis process to remove any remaining tastes and odors. An automated shut-off valve helps conserve water. The process is expensive on an industrial scale, and a huge amount of work has gone into bringing the cost down enough to be practical.
The waste product, brine, is then mixed back into seawater and returned to the ocean while the cleansed water goes through post-treatment (adding in minerals to match the taste of drinking water) and into storage tanks – ready to serve the public.
How the Poseidon Water Plant is Changing California
Desalination is more than a possibility for California: it’s a certainty. A $1 billion plant is being built in Carlsbad by Poseidon Water to provide drinking water for San Diego. That opens in November, while across six days in late August/early September, the International Desalination Association (IDA) World Congress 2015 takes place in the San Diego Convention Center. The county has at least 16 further plant proposals being processed.
When it opens, the Poseidon Water plant has the capacity to process 50 million gallons a day, and will be the largest desalination facility in the Western hemisphere.
The project is the result of twelve years of planning, followed by six years of regulatory approvals and permissions, but Poseidon has now made a 30-year Water Purchase Agreement with the San Diego County Water Authority, a public agency importing water from the Colorado River and Northern California to over 3 million homes.
The plant began construction in late 2012, using three contractors, and the 10-mile pipeline (that’ll run via Carlsbad and Vista to the San Diego County Water Authority’s Second Aqueduct in San Marcos) the following Spring.
Campaigners argue that, despite filters, desalination will have a negative effect on marine life, particularly micro-organisms. However, Poseidon stands by its so-called ‘environmental stewardship,’ which includes wetland restoration, carbon footprint reduction, and preservation of the Agua Hedionda Lagoon.
Is Desalination the Future?
Further concerns include costs potentially exceeding other solutions, and the ejection of brine, rendering seawater into a lifeless area. This stands not only to help wealthy areas like california, but to provide clean water to areas of the globe that have never potentially had access to it. For the most vulnerable people on Earth, desalination technology could literally be a lifesaver.
But what do you think? Have you suffered from drought? Do the negatives outweigh the benefits? Let us know below.