By Doug Owen
Solving California's drought is just a flush away
With water restrictions in place across California and a low snow pack, many believe California has run out of water. But most do not realize California has several alternative water sources, primarily from treating and reusing wastewater and stormwater. Yes, there is the yuck factor to overcome when drinking treated water that was once flushed down the toilet, for instance. But technologies are in use today that make California’s treated wastewater and stormwater runoff safer to drink than bottled water.
As a water engineer for ARCADIS and an industry expert who has devoted my life to educating governments and enterprises about water resources, I offer three important water alternatives local municipalities should pursue, in addition to conservation, to help offset drought years.
1. Re-using wastewater – Every day in California, billions of gallons of highly treated wastewater are discharged into the ocean that could be recycled. Studies estimate that treated wastewater could yield more than 1 billion gallons a day of potable water, enough to meet the needs of more than 8 million Californians. Today's purification technologies — combining micro- or ultrafiltration, reverse osmosis, ultraviolet disinfection and advanced oxidation — are safe, reliable and leave the water cleaner than most bottled water. Case in point: Orange County is re-using 70 million gallons of treated wastewater per day to recharge its aquifer and is currently commissioning another 30 mgd.
2. Re-using stormwater – A one-inch rain storm in L.A. County can produce more than 10 billion gallons of runoff, with most of that water ending up in the Pacific Ocean. Capturing runoff and recharging depleted ground water aquifers, or treating it for urban and industrial use, is more beneficial. Stormwater runoff in San Francisco and Southern California could recharge local water supplies by between 420,000 and 630,000 acre-feet per year, or about the same as the water used by L.A. in one year.
3. Desalination of sea water – The Carlsbad desalination plant, designed by ARCADIS, will go online this fall near San Diego and is expected to deliver 50 million gallons per day or 7 to 8 percent of San Diego County’s potable water for residential, agricultural and industrial use. In Santa Barbara, the city council just voted to reactivate a mothballed desalination plant at a cost of $55 million. It’s a tactical approach to enhance the water portfolio in areas where drought is expected for long periods.
Historically, many California cities have relied on importing water from long distances through aqueducts and pipes over mountains. In terms of cost, energy requirements, environmental considerations and reliability, importing water over long distances is not sustainable. And yes, it is important to conserve water in your home and business. But you can’t conserve your way out of an extended drought.
The amount of water on Earth doesn't change. Throughout time, all water is reused water. Recycling water is drought-proof, cost-competitive and safe.
ABOUT THE AUTHOR
Doug Owen is Executive Vice President and Chief Technical Officer of Water for ARCADIS North America, Board Chair for WateReuse Research Foundation, and board member of the Water Environment Research Foundation. He is a published author on water resources, policy and treatment and is based in San Diego.