Desalination During Drought: Solutions to a Growing Demand for Water
Clean drinking water is fundamental to all life. As 2015 marks the end of the United Nations’ International Decade of Action recognizing water and sanitation as a basic human right, it also marks the beginning of a new era of water supply and usage across the state of California.
Since a statewide drought began four years ago, California lawmakers have struggled to find rainfall-independent solutions. This is not the first time California has turned to desalination as part of a larger plan to tackle decreasing water levels and drought conditions. The multiple-year drought in the 1980s led to the construction and opening of the Charles E. Meyer Desalination Plant in Santa Barbara. When rainfall returned just three months after the plant opened, the facility was mothballed. Forward-thinking experts kept up plant maintenance in the meantime, knowing it would not be the last time such measures would be considered or implemented.
There are also costs and other types of resource usage issues to consider. For instance, much of Southern California’s drinking water travels hundreds of miles from its origin in the Colorado River, transported using a massive and expensive aqueduct and conveyance system. With this current drought comes an opportunity to revisit tabled solutions and better prepare future plans to make desalination part of a larger framework to continue to keep California watered.
Desalination is not a silver bullet. But technology has improved the process and subsequently lowered the cost. Stuart White, director of Sydney, Australia’s Institute for Sustainable Futures, has called the need to plan for future plants “desalination readiness.” In Australia, as in many other arid, desert-like parts of the world, desalination has become a necessary and useful part of a plan to increase water resiliency and drought preparedness. The capacity of large desalination plants is quantified by how many millions of gallons of water per day (MGD) the plant produces, with Sorek, the world’s largest seawater reverse osmosis plant located south of Tel Aviv, producing 165 MGD. The largest desalination plant using membrane technology, which typically uses energy recovery devices such as the PX Pressure Exchanger, is Magtaa in Algeria, with a capacity of 132 MGD.
In the following pages, we’ll consider the success stories of desalination in California coastal cities, in Israel, and in Perth, where desalination helped pull the Australian city back from the brink of disaster during a decades-long drought. We’ll also look at other examples that circle the globe. Spain recycles 17 percent of its effluent, the second highest percentage worldwide after Israel, which treats 86 percent of its wastewater and irrigates more than half its crops with treated effluent. Domestically, states with desert climates, including Texas, are considering adding desalination plants to their resource management portfolio as a way to stay ahead of disaster and move ahead with progressive, affordable technological solutions to an age-old problem.