Carlsbad desalination plant

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Carlsbad desalination plant
Carlsbad desalination plant3.jpg
The site of the Carlsbad desalination plant is between the lagoon and the Encina Power Station. This view is looking from north to south, prior to construction of the desalination plant
Carlsbad desalination plant is located in San Diego County, California
Carlsbad desalination plant
Location within San Diego County
Desalination plant
Location Encina Power Station, Carlsbad, California
Coordinates 33°08′11″N 117°20′13″W / 33.13639°N 117.33694°W / 33.13639; -117.33694Coordinates: 33°08′11″N 117°20′13″W / 33.13639°N 117.33694°W / 33.13639; -117.33694
Estimated output 50 million US gallons (190,000 m3) per day
Cost US$1,000,000,000[1]
Technology Reverse osmosis
Percent of water supply Estimated 7% of San Diego County
Website Official website (see Project website note under External links)

Carlsbad desalination plant is a desalination plant under construction in Carlsbad, California, adjacent to the north end of the Encina Power Station.[2] The San Diego County Water Authority (SDCWA), the recipient of the fresh water produced by the plant, calls it "the nation’s largest, most technologically advanced and energy-efficient seawater desalination plant." The entire desalination project is expected to cost about $1 billion for the plant, pipelines, and upgrades to existing SDCWA facilities to use the water. It is scheduled to begin operations in late 2015.[3]


The idea of a desalination plant in San Diego County, California began in 1993 after a five-year drought.[1] Membrane technology used in the plant was pioneered by General Atomics in La Jolla.[4] Environmentalist opposed the construction due to multiple reasons, including brine discharge.[1] Another reason is a concern that ocean water intake could kill fish.[5] Fourteen lawsuits were brought against the plant, including by Surfrider Foundation, and none were successful.[4][6]


The plant construction started in December 2012, and was originally scheduled to be completed in 2016.[6][7] However, due to the California Drought plant completion has been advanced to late 2015.[8] The plant is now estimated to be completed in September.[9] After the plant is completed, it will go through a six-month "commissioning" process, where it will be thoroughly tested before being put online.[9]

The fresh water output from the plant will be sent by a 10 miles (16 km) long 4.5 feet (1.4 m) diameter pipeline, utilizing six pumps, to connect to the SDCWA distribution system in San Marcos.[10] Pipeline construction began in 2013,[11] and completed June 28, 2015.[12]

Poseidon Water is building the plant.[13] The main engineering companies on this project are GHD Group and US-based Butier Engineering Inc.[14][15][16] IDE Americas Inc., a subsidiary of Israel-based IDE Technologies, is designing the plant. IDE Technologies is jointly owned by Delek Group and Israel Chemicals.[17][18] Simon Wong Engineering was subcontracted to provide the design and structural engineering services.[19] J.F. Shea Company and Kiewit Corporation are constructing the plant.[20]

The plant has taken nearly 14 years to be built.[4] The total project cost is expected to reach near $1 billion; initial cost estimates were a quarter-billion in 2004, to six hundred ninety million in 2010.[21] The cost of construction was funded by bond sales.[6] In late-2012, Fitch Ratings gave the bonds the lowest investment grade rating.[22] Upon completion, it will be the largest desalination plant in the Western Hemisphere.[6]

Environmental concerns[edit]

1,000,000 US gallons (3,800 m3) per day of cooling water from the Encina Power Plant will be taken into the desalination plant.[23] The water intake will be filtered through gravel, sand, and other filters before going through reverse osmosis filtration.[24]

The outflow of the plant will be put back into discharge from the Encina Power Plant, for a final salt concentration of about 20% extra salt than normal seawater. Most desalination plants discharge water with about 50% extra salt, and this high a concentration leads to dead spots in the ocean because the super-salty water doesn't mix well with normal seawater.[24]

Solar panels will be installed on the roof of the plant, and carbon emission offsets will be purchased.[25]

To offset environmental impacts, sixty-six acres of wetlands were built in San Diego Bay.[6]

San Diego Coastkeeper is suing the SDCWA over environmental concerns. On July 29, 2015 they argued in a hearing before Superior Court Judge Gregory Pollack that the Authority's long-term water plan (and specifically the Carlsbad desalination plant) violates the California Environmental Quality Act, specifically with respect to energy needs and the greenhouse gasses associated with those. Coastkeeper is not opposed to desalination, but wants proper mitigation. The Authority says that these have been accounted for, and a mitigation plan has been put into place.[26]

The Encina Power Station will be going offline (planned for 2017), and Poseidon Water will then take over dredging responsibility for the Agua Hedionda Lagoon, taking over from NRG;[27] without dredging at the mouth of the lagoon, it will revert to being a pre-1952 mudflat.[28]

Water quantity and cost[edit]

The plant is expected to produce 50 million US gallons (190,000 m3) of water per day[29] (0.069 cubic kilometres per annum) with energy use of ~3.6[30] kWh for 1 m3 fresh water, or ~38 MW of average continuous power.[6][31] Another estimate has the plant requiring 40 MW to operate, and a cost of forty-nine to fifty-four million a year.[1] It will provide about 7% of the potable water needs for the San Diego region.[4]

The San Diego County Water Authority signed a contract with the plant operator to purchase a minimum 48,000 AF/yr (acre-feet/year) of drinking water, but it can also demand up to a maximum of 56,000 AF/yr.[32][33] (Since one acre-foot is about equal to 1,233 cubic meters, the output would be a minimum of 59,184,000 cubic meters/year to a maximum of 69,048,000 cubic meters/year.) Another way of measuring this is that 1 acre-foot is normally enough water for two households of four for one year.[3][34]

The cost of water from the plant will be $100 to 200 more an acre-foot more than recycled water, and $1,000 to $1,100 more an acre-foot than reservoir water, but $100 to $200 less than importing water from outside the county.[35] As of April 2015, San Diego County imports 90% of its water.[10] A group of environmentalist groups, Desal Response Group, claims that the plant will cost San Diego County $108 million a year.[13]


  1. ^ a b c d Phillips, Erica E. (20 June 2013). "Water Plant's Long Journey". Wall Street Journal. Retrieved 6 June 2015. 
  2. ^ "City of Carlsbad - Seawater Desalination". City of Carlsbad. Retrieved 7 August 2014. 
  3. ^ a b
  4. ^ a b c d Perry, Tony (4 June 2015). "Backers of desalination hope Carlsbad plant will disarm critics". Los Angeles Times. Retrieved 6 June 2015. 
  5. ^ Roach, John (17 February 2014). "Parched California Pours Mega-Millions Into Desalination Tech". NBC News. Retrieved 7 June 2015. 
  6. ^ a b c d e f Rogers, Paul (29 May 2014). "Nation's largest ocean desalination plant goes up near San Diego; Future of the California coast?". San Jose Mercury News. Retrieved 5 June 2015. 
  7. ^ Jason Dearen; Alicia Chang (22 September 2012). "California Drinking Water: Desalination No Panacea For State's Woes". The Huffington Post (New York City). Associated Press. Retrieved 1 March 2013. 
    "Carlsbad Desalination Plant Pipeline Halfway Completed". KPBS (San Diego). 29 May 2014. Retrieved 6 June 2015. 
  8. ^ Gillis, Justin (11 April 2015). "For Drinking Water in Drought, California Looks Warily to Sea". The New York Times. Retrieved 12 April 2015. 
  9. ^ a b
  10. ^ a b Diehl, Phil (11 April 2015). "Carlsbad desalination project nears completion". San Diego Union Tribune. Retrieved 6 June 2015. 
  11. ^ Garske, Monica (29 March 2013). "Pipeline Construction Begins for Carlsbad Desalination Plant". KNSD (San Diego). Retrieved 6 June 2015. 
  12. ^
  13. ^ a b Weiser, Matt (18 October 2014). "Could desalination solve California’s water problem?". Sacramento Bee. Retrieved 7 June 2015. 
  14. ^ "Carlsbad 50 MGD Seawater RO Desalination Plant and Product Water Pipeline". Butier Engineering. Retrieved 7 August 2014. 
  15. ^ "Carlsbad Desalination Plant (CA, USA)". GHD Group. Retrieved 7 August 2014. 
  16. ^ "Australia's GHD to work on Carlsbad desalination". Desalin. Water Reuse (East Grinstead, UK). 23 March 2009. 
  17. ^ Udasin, Sharon (7 January 2013). "Israelis to design San Diego-area desalination plant". Jerus. Post. Retrieved 26 January 2013. 
  18. ^ Hackley, Randall (7 January 2013). "IDE Desalination Plant Project Contracts Valued at $650 Million". Bloomberg News. Retrieved 26 January 2013. 
  19. ^ "Major New Desalination Plant To Be Built In Southern California". Water Online. VertMarkets, Inc. 18 April 2007. Retrieved 6 June 2015. 
  20. ^ "Seawater Desalination" (PDF). The Carlsbad Desalination Project. San Diego County Water Authority. March 2015. Retrieved 21 May 2015. A joint venture of Kiewit Infrastructure West and J.F. Shea Construction, inc. designed and is building the desalination plant and pipleline. 
  21. ^ Lee, Mike (15 June 2012). "Carlsbad desal plant, pipe costs near $1 billion". San Diego Union-Tribune. Retrieved 6 June 2015. 
  22. ^ Barringer, Felicity (28 February 2013). "In California, What Price Water?". New York Times. Retrieved 7 June 2015. 
  23. ^
  24. ^ a b
  25. ^ Orlowski, Aaron (21 April 2015). "Desalination could provide O.C. an infinite water supply, but at a steep cost". Orange County Register. Retrieved 7 June 2015. 
  26. ^
  27. ^ Sifuentes, Edward (30 November 2014). "Agua Hedionda Lagoon dredging starts soon". San Diego Union Tribune. Retrieved 7 June 2015. 
    Thompson, Konny; Wells, Sam. "Tapping the Pacific". Carlsbad Magazine (Wheelhouse Media, LLC.). Retrieved 7 June 2015. 
  28. ^ Fokos, Barbarella (14 May 2008). "True Lagoon". San Diego Reader. Retrieved 7 June 2015. 
  29. ^ Gorman, Steve (11 December 2009). "Desalination project forges ahead in California". Reuters. 
    Odenheimer, Alisa; Nash, James (12 February 2014). "Israel Desalination Shows California Not to Fear Drought". Bloomberg Business. Retrieved 9 June 2015. The facility, when finished in 2016, will be able to provide 50 million gallons of potable water a day. 
  30. ^ Desalination of Seawater. American Water Works Association. 2011. p. 74. ISBN 978-1-58321-833-4. 
  31. ^[dead link]
  32. ^
  33. ^ Nussbaum, Daniel (5 June 2015). "Drought: Desalination MindsSupporters Hope $1B Carlsbad Plant Changes Critics' Minds". Breitbart. Retrieved 6 June 2015. 
  34. ^ Brennan, Deborah Sullivan (24 August 2014). "1st big desal plant for thirsty county". San Diego Union Tribune. Retrieved 7 June 2015. 
  35. ^ Rosenthal, Jessica (20 May 2015). "Desalination: Could One Of California’s Drought Solutions Backfire?". Fox News Radio. Retrieved 6 June 2015. 

External links[edit]

Project website note. Some of the webpages are formatted incorrectly so that in some browsers no numbers are displayed. For example, "The WPA commits the Authority to purchase a minimum ,AF/year of product water and provides the option to demand a maximum ,AF/year" could be displayed, although the actual text in the file is "The WPA commits the Authority to purchase a minimum 48,000 AF/year of product water and provides the option to demand a maximum 56,000 AF/year." If you experience this problem, you have three options: (1) try another browser, (2) copy and paste the displayed text into a document and the text should show correctly, or (3) view the page source in HTML.