An aerial view of the demonstration-scale subsurface seawater intake and discharge facility installed at Cherry Beach. Photo courtesy of the Long Beach Water Department.
UPDATE Wednesday, July 20, 4:03pm | The Under Ocean Floor Seawater Intake and Discharge System being used by the Long Beach Water Department to research desalination processes is funded by Proposition 50.
California voters approved the ballot measure, also known as the Water Quality, Supply and Safe Drinking Water Projects, Coastal Wetlands Purchase and Protection Act, in 2002. It authorized the sale of $3.4 billion in general obligation bonds for a variety of water-related projects including desalination efforts.
Desalination has continued to remain too costly in terms of the amount of energy required to complete the process, and while significant advancements have been made, overall energy consumption remains what water department officials described in 2005 as “extremely high” due to the high-pressure requirements of reverse osmosis membranes.
As of 2005, the Long Beach Water Department had successfully slashed the overall energy requirement by 20 to 30 percent using a small, 9,000 gallon-per-day pilot-scale desalter featuring a relatively low-pressure, two-staged nano-filtration process developed by Long Beach water engineers. That process is now known as the “Long Beach Method.”
It was based on this success that the state’s Department of Water Resources granted the city of Long Beach $3 million in 2005 to construct a 300,000 gallon-per-day prototype-scale desalter.
Costs for both the prototype-scale desalter and the seawater intake and discharge system are additionally being covered by two funding partners, the U.S. Bureau of Reclamation and the Los Angeles Department of Water and Power.
Tuesday, July 19, 1:01pm | The California Coastal Commission on Thursday, July 14, granted the Long Beach Water Department a five-year extension on its coastal development permit, meaning the department will be able to conduct five additional years of seawater intake and discharge research.
The department’s Under Ocean Floor Seawater Intake and Discharge System was slated for removal in May 2012, but the extension allows the facility to remain in place through May 2017.
Dr. Suzanne Dallman, president of the Long Beach Board of Water Commissioners, said the extension is important to the city’s future in terms of identifying a reliable water supply as the natural resource becomes more and more scarce.
“As the cost of imported water continues to increase, it is critical that we seek out alternative, environmentally responsible sources of water that can provide Long Beach with an essential supply of reliable water,” Dallman said in a statement.
The Long Beach Under Ocean Floor Seawater Intake and Discharge System is the first seawater intake project of its kind in the United States. It is also a “vital” piece of the Long Beach Desalination Project, an ongoing national research and development partnership between the water department and the U.S. Department of Interior’s Bureau of Reclamation, according to information provided by Matthew Veeh, a water department spokesman.
It was constructed to demonstrate a cost-effective, environmentally responsible alternative to more traditional seawater intake and discharge practices used around the world, which often result in the destruction of ocean habitats and species.
Kevin Wattier, general manager of water department, said that once seawater desalination becomes cost effective, the city aims to use it to provide roughly 10 percent or more of Long Beach’s annual drinking water supply.
“However, before we make that investment, we want to make sure that our process for bringing in seawater to a treatment facility is proven to have as minimal an impact on the surrounding ocean habitat as possible,” Wattier said in a statement. “With five additional years of research, I am confident that we will be well prepared to implement this environmentally sound intake process.”
The intake system employs a natural, biological filtration process that reduces organic and suspended solids. Veeh said this “largely” eliminates the need for additional pretreatment, results in a smaller overall energy footprint and lowers the cost of operation.
A full-scale, sub-ocean floor intake system with technology identical to that which has been constructed in Long Beach currently exists and is in operation in Japan, It was constructed several years ago at a 25-million-gallons-per-day seawater desalination facility in that country, Veeh said.