- Voice of San Diego - https://www.voiceofsandiego.org -

Wastewater Recycling and Conservation Aren’t Enough — That’s Where Desal Comes in

The same old arguments [1] against desalination keep getting resurrected: It’s too expensive, too energy intensive, plus wastewater recycling and conservation by themselves can solve the drought problem. When put in the context of climate change, imported water and perpetual drought, none of these arguments make sense.

Climate scientists are unequivocally telling Southern Californians to prepare for drought as the “new normal” (we are now experiencing the hottest year on record in the midst of the fifth year of punishing drought). Because the sale of Carlsbad desalinated water is governed by contract, the cost of water to ratepayers has been limited to approximately $5 a billing, regardless of how much it cost to build the facility. Whereas the cost of imported water, which all of Southern California is dependent on, had gone up more than 6 percent a year before the drought and is predicted to rise as the commodity becomes more scarce due to drought, demand and fights over the water [2], which continue to escalate both within California and inter-state in the case of Colorado River water.

Commentary - in-story logo [3]Opponents of desalinated water always refer to energy use without putting it in the context of importing water and other daily electrical uses. It takes approximately 14,000 kilowatt hours per million gallons to import water to Southern California, and approximately 15,000 kilowatt hours to produce the same million gallons from desalination, so it’s essentially a wash. It takes 7.6 kilowatt hours to produce a daily supply of desalinated water for the average household using Carlsbad water, substantially less than other daily uses: 24 kilowatt hours for central air conditioning; 13.2 kilowatt hours to charge an electric vehicle, 12.5 kilowatt hours for electric hot water and 19.4kilowatt hours to run one server in a data center.—

Wastewater recycling and conservation are obviously necessary to do. By themselves, however, they cannot possibly overcome drought, dependence on imported water and expected population growth for the region. As drought and conservation take hold, there is less wastewater to recycle. Indeed, the Orange County Water District, now negotiating to purchase the entire 50 million gallons a day from the proposed Huntington Beach plant, has predicted a substantial shortfall of water by 2035, and that’s despite its wastewater recycling and conservation programs. And it is important to note that conservation means water districts will inevitably raise rates to cover the loss of income from water purchases by consumers.

The fact is, desalination’s time has come because it is necessary for water-starved 21st century water portfolios to include it. In addition to the proposed plants mentioned (Huntington Beach, RosaritoBeach and Camp Pendleton),desalination is on the drawing board across Southern California, including in Los Angeles County, Oxnard, Santa Barbara and San Luis Obispo.

To continue to debate this issue out of context does a disservice to responsible discussion.

Robert Sulnick is the executive director of OC WISE, a coalition that supports the development of all forms of new drought-proof local water for Orange County. Poseidon Water, which owns and operates the Carlsbad Desalination Project, is a member of OC WISE.