In the News

Desal: New study highlights energy concerns as publication of critical environmental eval nears

By J.M. Brown
Santa Cruz Sentinel, 5/2/13

SANTA CRUZ -- As the city and a neighboring water district prepare to release a critical environmental analysis of a proposed desalination plant, a well-regarded research group has published a new report evaluating the high level of energy required to operate such facilities.

The Oakland-based Pacific Institute concludes the energy needed to remove salt from seawater -- much higher than treating water from rivers, streams and underground aquifers -- could exceed current estimates as economic and environmental conditions vary. Fluctuating energy prices and the tendency of those costs to soar during hot and dry periods when the plant will be most needed create uncertainty about the real effects, researchers found.

"Desalination -- through increased energy use -- can cause an increase in greenhouse gas emissions, further contributing to the root cause of climate change and thus running counter to the state's greenhouse gas reduction goals," according to the report, one in a series of desalination studies planned by the institute.

Officials with the city and Soquel Creek Water District, who plan to release an environmental impact report May 13, have acknowledged the plant's energy will be 7-12 times higher than treating conventional sources. But the system will be outfitted with high-efficiency recovery devices to redistribute energy, while pumps, motors and salt-removing membranes will be designed to limit energy consumption.

The two agencies that want to build the plant to protect against drought and rest overtaxed aquifers also will consider funding efficiencies elsewhere in the water system or buy renewable energy credits outside to bring the net greenhouse gas emissions to zero.

"These are all very consistent with what the Pacific Institute has identified as ways to reduce energy and greenhouse gas emissions," said Melanie Schumacher, an engineer with district.

Desalination technology is not likely to improve enough to make a significant impact without offsets, the institute found.

"The industry itself doesn't anticipate a major reduction without some major technological breakthroughs," Heather Cooley, co-director of the institute's water program, said Thursday. "The feeling is with some of these energy recovery devices, there are opportunities to make improvements around the margins."

But Cooley also cautions that offsets could be used to reduce existing emissions rather than create new ones. She also notes the energy used in conveying new water to customers and eventually treating some of it as wastewater must be considered as part of the overall impact.

Cooley said the 17 communities in California and Mexico where plants are proposed have to compare the impacts to alternatives, such as conservation, wastewater recycling and stormwater capture.

"How you weight them is sort of based on community interest and values," she said.

The public will have two chances next week to learn more about desalination plans.

Monday, the Santa Cruz Water Commission will look at options for financing the $128 million facility and the potential for more conservation. Tuesday, the City Council and the Soquel Creek district board will host a joint session to review what the environmental report will cover and how the public can comment once it is published.

Both meetings will be at 7 p.m. in the Council Chamber.

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WHAT: Joint meeting of the Santa Cruz City Council and Soquel Creek Water District board to discuss the process for evaluating the draft environmental impact report for a seawater desalination facility.

WHEN: 7 p.m. Tuesday

WHERE: Council Chamber, 809 Center St., Santa Cruz

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