Department of Water Resources
A daily compilation of significant news articles and comment
August 4, 2008
4. Water Quality –
Desalination plan going back to coastal panel
Pump uses less energy to desalinate water
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Desalination plan going back to coastal panel
By Michael Burge, Staff WRITER
The approval came with 22 conditions.
Poseidon returns to the commission Wednesday with a plan to satisfy those conditions. If it goes well, the company hopes to get final approval to build the plant on the south
The most significant conditions address how to compensate for fish and small marine organisms that will be killed in the desalination process, and how to neutralize carbon emissions that will result from plant operations.
The commission's staff and Poseidon officials have a history of differences.
The staff rejected Poseidon's application four times before deeming it complete last August and ready to send to the commission – with a staff recommendation to deny the plan.
The commission approved Poseidon's application Nov. 15 on a 9-3 vote after an 8½-hour hearing that included speeches from public officials who supported the plant and environmental activists who opposed it.
Poseidon proposes building the
The $300 million project would take 100 million gallons a day from the power plant's stream and demineralize half of it to produce 50 million gallons of drinking water a day. The other half would be returned to the cooling stream twice as salty, but it would be diluted to reduce the salt concentration before going back to the ocean.
Environmentalists oppose Poseidon's proposal because of the number of fish, larvae and small organisms that would be trapped and killed in the desalination process. The Surfrider Foundation and the Planning and Conservation League sued the Coastal Commission over its approval of the project, saying the proposed plant would harm marine life.
Poseidon officials and the commission's staff also differ over how to implement conditions designed to reduce greenhouse gas emissions and compensate for marine deaths.
The commission's staff wants the plant to abide by standards set in 2006, when
The staff recommends that Poseidon offset 100 percent of the emissions the plant will contribute through its operations, but Poseidon says that is too stringent.
Poseidon has proposed reducing energy consumption at the plant while creating renewable-energy projects and taking other measures to offset the plant's energy use.
Company officials say they should not be required to offset 100 percent of the plant's emissions, because the desalinated water would replace water now being imported from
They say Poseidon should be responsible only for the energy the desalination plant requires above the amount of electricity used to transfer water from Northern to
“It's a big deal for us,” said Peter MacLaggan, Poseidon's senior vice president.
“It represents a five-to tenfold increase in our costs of implementing this condition. . . . It could drive up the cost to the point where it could make it difficult for us to finance the project.”
MacLaggan said
The commission's staff differs with Poseidon over whether water from the desalination plant would replace imported water.
Commission scientist Tom Luster said documents from the Metropolitan Water District – the region's wholesale water provider – say that if some local agencies use desalinated water, Metropolitan either could import less water or redirect it to other customers.
In other words, Luster said, someone else could get the imported water.
“It doesn't appear to us that you're necessarily going to result in reduced water imports and thereby reduce emissions,” Luster said.
MacLaggan said even if that is so, it's beyond the control of Poseidon and its customers. Moreover, Poseidon officials say the greenhouse gas law doesn't apply to their operation.
“Under the Coastal Act, (coastal commissioners) don't have the authority to require greenhouse gas mitigation,” said Scott Maloni, a Poseidon vice president.
Stanley Young, a spokesman for the California Air Resources Board, which is drafting regulations to enforce the law, agreed. Young said that the law applies only to plants that directly emit gases and that the desalination plant will buy electricity off the statewide electricity grid.
Luster suggested referring the issue to the California Air Resources Board and California Climate Action Registry for their opinion.
The other condition still in dispute involves how much new marine habitat Poseidon must create to make up for the fish and other organisms that will be killed in its desalination process.
Poseidon proposes creating 37 acres of marine habitat, possibly at San Dieguito Lagoon.
The commission's staff says that acreage is insufficient and that 55 acres to 68 acres are needed. Luster said the scientist in charge of the San Dieguito Lagoon project analyzed Poseidon's proposal and advised that 37 acres would not provide enough new habitat to make up for the damage to marine life in Carlsbad. #
http://www.signonsandiego.com/news/northcounty/20080804-9999-1m4desal.html
Pump uses less energy to desalinate water
A
The PX Pressure Exchanger developed by Energy Recovery Inc. recently propelled the 68-person company into an initial public offering in a market that has been risk averse because of the nation's economic uncertainty.
Since Energy Recovery went public in July at $8.50 per share, raising $68 million, its shares have risen in a down market - closing Friday at $11.34 - based on sales and expectations that demand for desalination plants will continue to rise as coast-hugging populations turn to the oceans. As the company told potential investors in its prospectus, "growth in the market for new total desalination capacity should increase by approximately 13 percent per year from 2005 to 2015."
Revenue has grown from $4 million in 2003 to $35.4 million in 2007.
Energy Recovery Chief Technology Officer Richard Stover said the energy-saving pump is a tiny but pivotal component in what are huge desalination plants.
State-of-the-art desalination plants suck in seawater and then use electricity-driven pumps to put it under pressure. This salty stream is then slammed against filters designed to let the fresh water bleed through while sequestering the high-pressure brine - a process called reverse osmosis.
"It takes a lot of pressure to get the pure water to go away from the salt, and it takes a lot of energy to pressurize the water," Stover said.
That's where Energy Recovery comes into play. The company designed its pump to capture the pressure trapped in that left-behind brine and recycle its energy into repressurizing the next batch of virgin seawater destined to be slammed against those reverse-osmotic filters.
All that sucking and pressurizing consumes gobs of electricity, and power expenses account for one-third to one-half of the total cost of seawater desalination, according to the Pacific Institute, a nonprofit think tank in
Heather Cooley, an environmental biologist and desalination expert at the institute who has toured Energy Recovery's
So far, Wall Street seems to feel the same, as shares in this new company remain strong in a weak market. In its prospectus, Energy Recovery tells potential investors that most of its sales have come from parched foreign locales like
But Cooley says 19 desalination plants are on the drawing boards in
That plant, being promoted by Poseidon Resources Corp. of
But Amy Zander, a professor of environmental engineering at
"It's not a bad analogy, because perceptions are not always based on truth in either case," said Zander, who says saltwater desalination could work for some communities, but urges more study of the environmental consequences and alternatives such as purifying wastewater.
For the record, Energy Recovery isn't betting that
Desalination nations
Less than half a percent of human water needs are now met through desalination, or saltwater purification. The five top users:
Sources: Pacific Institute, Chronicle research#
http://www.sfgate.com/cgi-bin/article.cgi?f=/c/a/2008/08/02/BUQN122TTL.DTL
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