Feature Stories
The Future of Long Beach Water
by Bryon L. Richards
There has been something going on down on the sands of Long Beach. A tall crane and some other engineering odds and ends have been seen by many as they drive down Ocean Blvd. at the foot of the bluffs at Junipero Ave.
The Under Ocean Floor Intake & Discharge Demonstration System is an experiment by the Long Beach Water Department in an attempt to turn seawater into clear, high-quality drinking water. Called “The Long Beach Method,” the procedure aims to save energy by pushing seawater through two membranes at less pressure than traditional desalination technology.
The Nanofiltration membranes are made of semi-permeable material that allows almost nothing larger than pure water molecules to pass through. Because they are larger than water molecules, most salt molecules and other materials are left behind.
Visually, compare water molecules to tennis balls, salt molecules to softballs, viruses and bacteria to vehicles and buildings and shoot them through a barrier with holes only large enough for tennis balls, you get “The Long Beach Method.” The process also includes two barriers, compared with only one for traditional desalination processes, thereby increasing reliability of water quality.
The experiment or “demonstration” includes a system of pipes 30 feet under the sand where scientists can determine if they can capture and release water through natural sand filtration, as opposed to direct ocean intake. It is considered to be up to 30 percent more energy efficient than the current state-of-the-art technology.
The effort to turn sea water into clear water began almost 10 years ago, when the program received the green light for development by Congress on Oct. 9, 1996. The technology was invented by a retired Long Beach Water Department engineer and administrator, Deim Vuong. It had been his dream to turn ocean water into drinking water by inventing a unique and effective desalination process. In 2001, the city built a 300,000 gallon-per-day facility at the Haynes Generation Station grounds in East Long Beach that includes the two-stage Nanofiltration system.
The object of the plant is to research ways to reduce the city’s reliance on outside water sources by at least 10 percent. Imported water has become more expensive and is the biggest expenditure for the water department.
The research is receiving positive federal and state support, not only through funding but with scientists from those agencies participating in the research and is the largest effort of its kind in the U.S. There is a tremendous effort to become “green” or “eco-friendly” and the project also focuses on finding a “natural filter” on the sandy sea floor, eliminating compacting ocean species that would otherwise be destroyed during the intake of the ocean water or possibly injured in the discharge of highly concentrated brine.
Modern seawater desalination plants typically consist of three major unit operations: seawater intake, treatment (pretreatment and/or desalination), and brine discharge. Traditionally, seawater intake is carried out using open ocean intakes which draws seawater through a meshed intake screen and then is conveyed to the desalination plant. This is where a negative impact on the environment happens as marine microorganisms become impinged in the screens.
While the intake screens prevent debris and most aquatic life from entering, elevated levels of suspended solids and other constituents still have to be removed. Prior to the desalination process, the raw seawater collected through the open ocean intake undergoes pretreatment and these processes are very expensive as they use tremendous amounts of energy.
The project “is an all-inclusive seawater desalination system that is only focused on reducing energy requirements and improving the water-quality requirements,” said Ryan Alsop, director of governmental and public affairs for the Long Beach Water Department.
With the “Under Ocean Floor Seawater Intake and Discharge Demonstration” system, the negative environmental impacts typically associated with open ocean intakes are minimized which in turn also saves money.
In September of 2006 the desalination process received a patent from the United States Patent and Trademark Office which opens up the possibility of the city earning significant revenue from the sale of this method to other governments and private companies. This could mean lower water rates for customers.
If all this research proves successful, Long Beach hopes to build a full-scale project to handle 10 million gallons per day.
According to Alsop, the ultimate goal of the project is to prove the feasibility of an “economically and environmentally responsive method of collecting seawater, producing potable water, and disposing of brine.”
“I grew up in Long Beach and I would find it exciting if this project cleans up the water and brings back people to the beaches,” said Joe Vega, a spectator of the operation.
More information can be found at www.lbwater.org.
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