The Role of Desalination in an Increasingly Water-Scarce World

The removal of salt from seawater (desalination) is bitterly opposed by the California environmental community and its supporters in academia, government, and the press. 

Los Angeles Times editorial columnist Steve Lopez, a four-time Pulitzer Prize finalist, grudgingly acknowledges that “Desalination may have a role to play in addressing California’s long-running water shortage; after all we have got an 1,100-mile coastline in a drought-stricken state. It’s only natural to think: ‘Hey let’s just stick a straw in the ocean, and our rabid thirst will be quenched once and for all.’”

His opinion piece titled, “Desalination Plan Stinks all the Way to Sacramento,” goes on to dismiss desalination as too costly; too environmentally insensitive to both the ocean and the atmosphere; too unpopular with locals; too expensive to build; too energy inefficient; and too profitable for private companies such as Poseidon Resources, which for 20 years has been trying to win approval for a desal plant in Huntington Beach.

The Sierra Club goes even further than Lopez, claiming that desal plants are “eyesores that pollute the air, destroy the ocean, kill marine life, cost a fortune, and aren’t needed.” According to Sierra Club supporters, conservation alone can solve our water insecurity problem.

Case for Desalination of Sea Water

Desalination is a reliable source of water; it does not depend on rainfall nor snowfall in the High Sierras, nor attaining water from the depleted Colorado River Basin, Lake Mead or Lake Powell. It is immune to prolonged periods of drought; hence, it is an efficient way to build climate change resilience, an advantage to California environmentalists.

Desalination is a mature technology. In 2018, there were 18,426 desalination plants in some 150 countries producing 87 million cubic feet of water per day. Collectively, desal facilities supply some 16 million acre-feet per year (AFY) of clean water to more than 300 million people, according to a March 2019 study by the World Bank Group titled, “The Role of Desalination in an Increasingly Water-Scarce World.”

The Pacific Reservoir

Water covers almost 70% of the world’s surface. The Pacific Ocean is the largest and deepest water reservoir on Earth, covering more than 60 million square miles and averaging a depth of 13,000 feet. It holds more than half of the Earth’s open water supply. For California coastal communities, it is an unlimited supply of feedstock that lies right next door. 

Why is desalinated water so bitterly opposed by the environmental community and the state’s elected leadership? Is it possible to separate old myths from new realities?

Is Desalinated Water Too Expensive?

New surface reservoirs in California with their adjoining dams, like Lake Cachuma and Bradbury Dam, cost a minimum of $1 billion to build. The Pacific Reservoir costs nothing because nature placed it adjacent to 26.7 million coastal Californians.

As desalination costs have plummeted, the cost of pumping unreliable state water hundreds of miles continues to rise. The Montecito Water District (MWD) received only 5% (165 AF) of its promised 3,300 AF allotment of state water in 2020-21. That means state water cost MWD $5.2 million for 165 AF, or $31,500 per AF. Even more nonsensical is MWD’s obligation to pay another $5-6 million in 2021-22 for state water and not receive one drop of water. 

On the production side, the cost of desal water has been falling fast worldwide. In 2012, the cost of desal water was running at $2.38 per cubic meter in Israel. In the newest seawater desalination plants in Israel, such as Sorek II and Western Galilee, the Israeli bid from IDE Technologies, projects an “unprecedented low price” of $0.41 per cubic meter, equivalent $506 per AF, or $1.16 per HCF (hundred cubic feet). This lower cost will save Israel some $1.2 billion over the period that their new desal plants are in operation.

Compare the new $1.16 per HCF production cost in Israel to the retail price MWD ratepayers are now paying for water – from $6.75 to $12.66 per HCF, depending upon quantity of usage. City of Santa Barbara ratepayers pay even more, especially for use over 16 HCF per month at $25.89 per HCF. Comparing production costs to retail water costs ignores overhead costs, but the comparison is still striking.

Operating costs for energy, labor, chemicals, etc. account for two-thirds of desal water production cost, while capital cost depreciation makes up the other third. If you want to lower the cost of desal, it’s very straightforward: Mega-desal plants are more efficient than small plants. Lower the cost of plant construction by cutting the time and cost of regulatory approvals. Fund the desal plant with low-cost financing using government guarantees. Cut operating costs by using the lowest cost energy source available and install the latest membrane technology.

Desal plant contractors contend that decades of delay for government approvals, permits and environmental mitigations effectively kill viable desal projects because California’s permitting costs and time delays make it impossible to find reliable construction financing.

Is Desalination an Energy Hog?

The cost of energy for seawater desalination plants ranges from one-third to one-half of operations costs. Two of the biggest plants in Israel, Sorek I and Hadera, are located next to their own power plants to reduce energy transmission and distribution losses. Both use energy recovery systems to capture energy from the brine stream to drive their power pumps. Both use variable energy rates to run at maximum production at night when energy is least expensive.

Critics of desal plants forget that the State Water Project (SWP) is the largest single user of energy in California. Pumping one acre-foot of SWP water to Southern California requires about 3,000 kWh. That’s an average of 5 billion kWh per year, the equivalent of about 2 to 3% of all electricity consumed in California.

In Israel, the use of ERDs (Energy Recovery Devices) has cut energy costs by 60% to a new low level of 2kWh per cubic meter, compared to 14kWh per cubic meter for plants built in the 1990s.

In November 2017, Israeli start-up TSD (Tethys Solar Desalination) announced a break-through technology using photovoltaic cells (PC) for low-cost, off-grid, scalable and environmentally friendly module technology using only the power of the sun – no fossil fuels and no carbon dioxide emissions.

In May 2021, scientists in the Engineering School at Purdue University announced a variant of the Seawater Reverse Osmosis desalination process called “batch counterflow reverse osmosis” that can save even more energy costs and keep greenhouse gas emissions out of the atmosphere.

In July 2021, DuPont announced that it had been selected by the Sorek II desalination plant in Israel to provide its new FilmTech membranes that significantly reduce energy costs. Dupont officials and IDE Water Technologies, jointly predict that the new Dupont membrane technology will set a new benchmark for seawater desalination water prices on a global scale. 

Do Desalination Intake Systems Destroy Ocean Life?

Environmentalists decry the use of open ocean intake systems, such as the one permitted in Santa Barbara. Intake system mitigation measures in California can be enormously costly and delay desal plant openings for decades under claims that ocean intake systems harm fish larvae or plankton.

Jessica Jones, a spokesperson for the Poseidon desal plant in Carlsbad, California, puts the open ocean intake issue into perspective: “In our Carlsbad intake system we draw in tiny little organisms that amount to about a pound and a half of adult fish per day.”

New fish-friendly seawater intake pumps recently commissioned at the Carlsbad desalination plant are among the most environmentally advanced intake pumps in the world.  

Does Desal Brine Disposal Pollute the Ocean?

New desalination plants use advanced technology to mitigate, dilute and diffuse ocean brine discharge over large areas. The Carlsbad desalination plant outflow mixes two parts of ocean water with one part of briny water before discharge. A 2019 study of the Carlsbad desal plant, that dilutes its brine before releasing it, found that there were no direct impacts on marine life.

Continuous innovation in recovery of the brine stream has dropped costs significantly. In addition, marine engineers at MIT in February 2019 announced a new technology that turns concentrated brine into useful chemicals rather than returning it the sea.

Should Private Company’s Be Allowed to Own Desalination Plants? 

Today, nearly half of new seawater desalination plants are funded through the private capital markets. For example, the newer desal plants in Israel, and the Carlsbad desal plant that opened in December 2015, plus the proposed desal plant in Huntington Beach, put no taxpayer money or ratepayer dollars at risk.

Privately-owned Poseidon Resources funded all these projects through the capital markets. They privately raised the required equity and debt needed. Investors assumed the cost and risk of the plant design, engineering, permitting, construction and operating the facility for the first 25 or 30 years. After that, the water districts or government have the option of transferring ownership to themselves.

This approach is often described as a BOOT agreement — Build, Own, Operate and Transfer. Water districts or government entities are relieved of upfront capital investment and operating risks, while still creating public-private solutions for a more reliable long-term drinking water supply.

Should Desalination Receive Public Funding?

It may take time for our elected leaders to comprehend that privately financed desalination plants need to be a major part of our drought-avoidance strategies. Our two California Democratic Senators, Alex Padilla and Dianne Feinstein, introduced a bill in Congress on July 23, 2021, to boost funding for the Environmental Protection Agency (EPA) by $1 billion for innovative water infrastructure projects to improve resiliency against drought. The bill, co-sponsored by Senator Jon Ossoff (D-Ga), promotes groundwater recharge, stormwater capture and reuse and water recycling projects — but not one cent for seawater desalination capable of ending California’s water shortage and dependence on rainfall.

Conclusion

When Californians are allowed to take showers without flow restrictors and enjoy their gardens, and when farmers have enough water to grow food, water infrastructure in California will once again be adequate. The same nation that developed a COVID-19 vaccine within a year certainly can end the threat of future drought with a robust supply of new water solutions that are not dependent on rainfall.

The missing ingredient is a powerful constituency with the political clout to break down regulatory barriers, and boldly move forward with a widely shared vision and a sense of urgency to end the recurring threat of drought.

Next Week: Why Can’t California Be Greener Than Israel?

Editor’s note: This is the third in a five-part series about the water crisis facing Montecito, as well as California.