Over the next ten years, the expected swell in global population will undoubtedly lead to greater water needs and a rise in the production of wastewater. Already, as communities approach the limits of their available water supplies in their effort to meet the needs of potable, agricultural, industrial and commercial consumers, water reclamation and reuse are becoming necessary to conserve and expand the dwindling supply.
Alamitos Barrier Recycled Water Project
Located along the Los Angeles and Orange County border in California, the Alamitos Barrier protects a portion of the Central Basin, one of Los Angeles County’s largest groundwater basins, from seawater intrusion. Over time, overpumping of ground water basins has caused water levels to drop and seawater to enter the basins. To prevent additional contamination, seawater intrusion barriers were constructed along the coastline using potable water to source injection wells.
The Water Replenishment District of Southern California (WRD), in partnership with the City of Long Beach and Orange County Water District, headed up the Alamitos Barrier Recycled Water Project (ABRWP) to help conserve fresh water, supplying more than one third of the water used by four million people in the WRD service area. The ABRWP involved the construction of a state-of-the-art water treatment facility to further purify water from the Long Beach Water Reclamation Plant. Highly treated recycled water that otherwise would have been discarded into the ocean will serve as a partial substitute for the potable water that was used in the Alamitos Barrier injection wells.
This innovative and resourceful approach ensures that the region will do its part to reduce the demand on costly imported water supplies. The initiative is part of a diverse water supply reliability portfolio aimed at keeping water supply reliability high and water rates low. The Department's recycled water system expansion, when complete, will more than double recycled water use in Long Beach from 4,000 acre-feet to 9,000 acre-feet annually, eventually meeting 12 percent of the city's total water demand. One acre-foot of water is approximately 326,000 gallons.
The new $16 million Leo J. Vander Lans Water Treatment Facility, including a 3 mgd membrane facility, will be extensively monitored to ensure that quality standards are met and maintained – from blending of treated water with imported potable water to the product water pumped into Alamitos Barrier. The benefits of the new treatment facility include providing a reliable source of water even in droughts, decreasing imported water costs, increasing the use of recycled water and protecting the environment by promoting conservation. The WRD stated that the 50/50, potable/recycled water saves 3,000 acre-feet/year, enough to annually supply 6,000 families with water.
As part of the complete filtration package, Severn Trent Services provided one UAT™ reverse osmosis (RO) membrane treatment system, consisting of 756 membranes within 108 pressure vessels, designed to operate at 150 psi.
Membrane treatment technologies have proven to be successful processes for water reuse. As the global trend in water reuse continues to grow and prices for membrane systems continue to become more competitive, the reuse market can expect to see a greater influx of these technologies employed in a variety of applications.
Note: The Water Replenishment District of Southern California recently held a ceremony to transfer operations of the Leo J. Vander Lans Water Treatment Facility to the Long Beach Water Department. The Leo J. Vander Lans Water Treatment Facility will be the site of the afternoon technical tour on Tuesday, September 12, 2006 during the 21st Annual WateReuse Symposium in Hollywood, California. For additional information on this conference visit www.watereuse.org.
For more information, email info@severntrentservices.com