Launch Slideshow

Error: less than 300px wide output not yet supported

Sea of Life

Sea of Life

  • Image

    http://www.pwmag.com/Images/tmp484%2Etmp_tcm111-1334616.jpg?width=250

    true

    Image

    250

    The Carlsbad desalination plant is co-located with the Encina Power Plant, shown in the lower left of this photo with the smokestack. When the plant opens in late 2010, it will pump 100 mgd of ocean water through a reverse osmosis membrane filtering process to render 50 mgd of high-quality drinking water to roughly 350,000 citizens in San Diego County. Photos: Poseidon Resources Corp.

  • Image

    http://www.pwmag.com/Images/tmp485%2Etmp_tcm111-1334619.jpg?width=250

    true

    Image

    250

    Huntington Beach Desalinated seawater from the Huntington Beach plant will be introduced into Orange County's regional water supply system where it will be blended with drinking water from other sources. Twelve Orange County utilities and municipalities will have access to the desalinated water. In most cases, the plant will provide 1% to 10% of their water supply. Source: Poseidon Resources Corp.

  • Image

    http://www.pwmag.com/Images/tmp486%2Etmp_tcm111-1334625.jpg?width=400

    true

    Image

    400

    Seawater desalination projects in Southern California

Grover Beach, Calif., has put the ki-bosh on ornamental fountains and car washes. The city of about 13,000 residents has seen the light, or rather, the water.

Actually, the problem in this town, which lies about 170 miles north of Los Angeles, is that it's not seeing enough water. In June, the city council declared a water shortage and asked residents to conserve. Rainfall is 20% below normal, as it is in the rest of the state.

The whole state's drinking water crisis has escalated to the point of no return, so California is moving forward with cutting-edge technology to cost-effectively desalinate water, thus increasing the water supply.

The U.S. Census Bureau estimates that by 2030, the state's population will be 48 million, which would require more than 1000 mgd of new fresh-water supplies. Since this demand can't be met by relying on traditional sources, conservation, and reuse, the California Department of Water Resources (DWR) has turned to seawater and brackish water desalination. ( Click here to see a table of desalination projects in California).

For starters, Proposition 50, passed in November 2002, gave the DWR $50 million to do basic research on desalination. The projects—each of them small and focused on specific techniques—are part of $3.44 billion in general obligation bonds that will fund a variety of water projects. The first round of this program started in 2005 by awarding $24.75 million to 24 different desalination projects. The second round of the DWR program awarded another $21.5 million of grants to 23 projects in June 2006.

All of these research projects will be done by 2009 and will yield practical solutions to key environmental, energy, and cost challenges facing desalination today. For instance, Long Beach recently completed a 0.5 mgd demonstration plant that is used to test new technologies like reverse osmosis and nanofiltration.

The California desalination initiative is expected to yield more than 20 new projects statewide that would supply 400 to 500 mgd of new drinking water by 2020 and provide up to 10% of the state's total water demand by 2030. Click here to see a table of desalination projects in California

In the meantime, two large plants—not funded by Proposition 50, but through public-private partnerships with Poseidon Resources Corp.—are being developed. The projects, in the works since 1999, will produce 50 mgd of fresh water for about 80 cents more per 1000 gallons than current sources, but because they're using the existing intake and discharge facilities of co-located power plants, the desalination plants are expected to cost 20% to 30% less than previous plants to build. When completed, the two plants will be the largest seawater desalination plants in the Western hemisphere.

Both are fully funded by Poseidon Resources, and have a useful life of about 50 years. The municipalities and utilities that will be supplied with desalinated water from the two projects aren't taking on any financial risk with these plants, since permitting, construction, financing, and operating will be handled by Poseidon.

Making It Affordable

Currently, the cost of desalinating sea-water in California is higher than that of traditional low-cost water sources (ground-water and river water) and water reclamation and reuse for irrigation and industrial use. The cost of traditional local groundwater supplies in some parts of the state is as low as 50 cents per 1000 gallons. However, the quantity of such low-cost sources is limited: less than 30% of the water resources statewide.

Most water districts in Southern California buy and import water from the Sacramento Bay-San Joaquin River Delta, known as the “Bay-Delta,” and Colorado River at a rate of $1.50 to $1.80 per 1000 gallons. The cost of these water supplies is likely to increase 10% to 15% in the next five years because the EPA has beefed up its drinking water standards.

Based on Black & Veatch's 2006 California Water Charge Survey published in July 2006, the average residential monthly charge for 1500 cubic feet of drinking water was $36.39 ($3.20 per 1000 gallons). The survey also indicates that the cost of residential water supply has increased by 16.7% since 2003.

The confluence of lower construction costs and rising price of traditional water make the time right for California to push desalination to the forefront.

Piggybacked Savings

Southern California coastal water utilities expect to get 10% to 20% of their source water from the ocean by 2015.

Targeted for operation in 2010, the $270 million Carlsbad plant will provide 12% of San Diego County's water, which currently relies on Colorado River and the Bay-Delta for 90% of its drinking water supply. Eventually, this plant will supply all of the drinking water for the county's 350,000 residents.

Although at $2.70 to $2.90 per 1000 gallons the desalinated water is roughly 80 cents more than imported water, the project will provide a drought-proof water supply for 100% of Carlsbad's current and future water demand while increasing revenues: $2.4 million each year in property tax and $2.9 million each year in business tax.

To keep costs down, the Carlsbad plant will not have a separate ocean intake and discharge, reducing total capital building costs by 30%. Instead, the desalination plant will use the existing cooling water discharge facilities of the Encina Power Generation Station to collect seawater for fresh water production and to convey the desalination plant discharge to the ocean. Carlsbad's co-location approach makes the power plant's discharge a source of water for the desalination plant as well as a source of blending water that reduces the salinity of the plant concentrate to environmentally safe levels prior to ocean discharge.