Desalination on the Southern California Coast

A drought-driven controversial approach

Pacific-on-Tap-CarlsbadDespite a few days of steady rain this winter, enough to fill a few of California’s reservoirs to the three-quarter mark, the impact of the chronic water shortage in our state has been felt deeply. Drought-weary residents, particularly in Southern California, are feeling the pinch of increased conservation requirements, despite the huge water resource just steps away—the Pacific Ocean. But much to the chagrin of shipwrecked sailors and thirsty Angelenos, this vast reservoir of salt water requires a great deal of amendment to make it potable.

Due to high processing costs and environmental challenges, desalination technology has been a far-from-realistic option for generating clean drinking water. However, as hopes for an abundant El Niño winter solving L.A.’s water woes have evaporated, fears about the devastating impacts of a long-term drought have rebirthed visions of ocean desalination as a feasible solution for sustaining and increasing our water supply.

Last December, a billion-dollar reverse-osmosis desalination plant in Carlsbad, Calif., began pumping 50 million gallons of fresh water each day, meeting 7–10 percent of San Diego county’s water needs. There are at least a dozen more plants on the drawing board across the state, including one in the proposal stage near the El Segundo-Manhattan Beach border, and another in Huntington Beach, which is a 50-million gallon per day facility already in late-stage development.

Original Santa Barbara desalination plant, now being retooled
Original Santa Barbara desalination plant, now being retooled

In Santa Barbara, a desalination plant built in the late 1980s and operational until the wet years of the early ‘90s, when it was put on long-term standby mode, is scheduled to be back in service by October of this year, and to meet up to 30 percent of the city’s water demands.

A new policy for desalination was created last May by the California State Water Resources Control Board, setting up clean water standards as well as regulations for building below ground pipes to manage water flow, with the goal of lessening the environmental and financial impact of any of the slated new plants. Frances Spivy-Weber, vice-chair of the board, confirmed these regulations will apply to any new desalination plants in California, but do not cover the Carlsbad plant, having been adopted after it was approved.

Spivy-Weber cautioned that desalination might not work in every area. “My goal is that the policy will serve as a foundation for agencies and cities to look at desalination and fairly evaluate its cost,” she said. “In some cases it will work; in other cases it will be too costly; in other cases in won’t be appropriate.”

 

Recycled vs Salt

According to the Orange County Water District, “Purifying wastewater is about one-third the cost of ocean desalination, because there are far fewer dissolved solids (salts) to remove from wastewater (1,000 mg/L as compared to 35,000 mg/L in ocean water). Removing that high concentration of salts requires three times more energy, additional membranes, and a shorter reverse-osmosis membrane lifespan.”

L.A.’s Hyperion Water Reclamation Plant currently provides 40 million gallons of highly treated recycled water each day, with plans to nearly double that amount by 2020. But the West Basin Municipal Water District is proposing a massive new $300 million desalination plant in the South Bay, which would be the first full-fledged desalination plant in Los Angeles County. The goal is to convert 60 million gallons of seawater a day into drinking water for the 17 cities served by West Basin.

Ocean watchdog Heal the Bay, along with several local mayors and the Manhattan Beach city council, has raised strenuous objections, with concerns ranging from the environment to the coastline to cost. The district is scheduled to release its environmental impact report for the project in June.

 

El Niño Disappointment

Due to the significantly higher cost and hazards of these desalination processes, Spivy-Weber stressed that water conservation is not only better for the environment, it’s more cost-effective.

“If California wants to grow—in terms of numbers of people, but also its economy—it’s going to need a little more breathing room in its use of water,” she said. “That’s why conservation has been so important. Because it’s been that extra amount that has been needed to allow for drought and growth.”

The challenge with conservation is, however, having something to conserve. Despite ambitious initiatives and innovative conservation efforts, such as the StormCatcher Project, a public-private collaboration designed to capture and reuse storm rainfall, L.A.’s projected 2016 population of 3.947 million will be a strain if we continue to have dwindling supplies.

Steady rains have been a welcome relief, but by no means indicate our water challenges are receding. A colleague of Spivy-Weber colleague explained: “It’s like someone who’s been out of work for four years who [finally] lands a job and gets a paycheck, and it’s fabulous, but it doesn’t make the person financially healthy for several more years. That’s really the situation in California. We need several years of rain and snow, and particularly important for southern California, snow in Colorado, in the mountain systems that feed the Colorado River.”

 

Tech Hybrid

One local company has been making waves with its patented desalination technology. Effluent Free Desalination Corp (EFD), a start-up based in North Highlands, Calif., has devised a way of producing more drinkable water that they say is less disruptive of the ocean and consumes less energy. Mike Lord, vice president of engineering at EFD, claims his company’s technology can separate salt from ocean water through super heating to produce fresh water steam, distilled water and crystalized sea salt. The energy cost from this process is offset by the sale of the dry salt,

Salt byproduct can be diverted to commercial use
Salt byproduct can be diverted to commercial use

which can be shipped and sold at market, as well as the use of natural gas for energy. Any leftover brine (which contains twice the amount of ocean salt and does not contain oxygen) is re-circulated back through the system, with no brine returned to the ocean to suffocate marine life on the ocean floor (creating a “kill zone”) or affect climate change. (Standard desalination plants discharge brine under a range of conditions, often including ocean outfall.)

“Typical desalination technologies convert about 40 percent of the water into drinking water, and 60 percent of the water is returned as toxic brine,” Lord said. “Our technology converts 100 percent of the water taken out of the ocean into drinking water. One of the benefits of that is we reduce the amount of water that has to be taken from the ocean by 60 percent, because the very act of taking the water out of the ocean can damage the ocean. If you put a big pipe out in the middle of the ocean and suck in 50 million gallons of water a day, or in the case of Carlsbad, you pull in 120 million gallons of water a day, you get fish eggs, fish, larva and everything else. Even if you put a big screen over it, you still pull in small animals, and they all die. So not only do we impact the ocean from the water going out, but we also impact it by lessening the damage on the intake.”

Lessened damage is still damage. Lord notes there are more environmentally friendly techniques for collecting seawater, such as using subsurface slant wells

instead of open sea intakes, but these are more expensive.

Kill zone showing dying coral
Kill zone showing dying coral

EFD has also devised a way to reduce energy use. Lord notes that by comparison, “The Carlsbad plant consumes so much electricity that they actually affect the balance of power on the power grid. Our power grid has reached a fragile state as it is, so when you put these huge users of electricity on it, it has large impacts on the grid’s ability to support itself. When you build a desalination plant, you need to build an additional power plant.

“Our technology runs on natural gas; we don’t use any electricity. When we install our machine, we don’t impact the power grid by taking any power from it.”

Desalination is thriving in the Middle East, where options are fewer—it generates 70 percent of Saudi Arabia’s drinking water and 25 percent of Israel’s—but until now has been thwarted stateside by steep costs and environmental impact challenges. However, the 2014 California voter approval of a $7.5 billion water bond measure, along with hybrid solutions in the works to supplement enhanced watershed management, is bringing us closer to Mayor Eric Garcetti’s water conservation goals. Whether or not we’re closer to resolving our state’s long-term water requirements for survival and growth remains to be seen.

 

 

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This article is a part of the Our Fragile Planet April/May 2016 issue of Whole Life Times.