May 27, 2004 -- USFilter has completed installation of a temporary 6 mgd Memcor® Continuous Microfiltration Submerged (CMF-S) membrane filtration system at Orange County Water District's (OCWD) Groundwater Replenishment System (GWRS) project.
This initial system will provide injection water during the construction of the permanent 70 mgd Memcor system.
The GWRS is an indirect potable water reuse project that proactively responds to Southern California's future water needs by using advanced multi-barrier filtration techniques to provide an alternative to wastewater discharge to the ocean; act as a seawater barrier; and provide a drought-proof source of high quality drinking water.
After nearly a decade of research and extensive pilot studies at the world-renowned demonstration site known as Water Factory-21, the OCWD demonstrated that advanced treatment techniques combining a dual-media membrane process with disinfection can treat wastewater to drinking water standards.
Upon completion of the rigorous process of demonstration testing with three system suppliers, the OCWD accepted a $27M bid from USFilter for its CMF-S membrane filtration system. This technology is followed by reverse osmosis (RO) and ultraviolet disinfection. When completed in 2007, the treatment technology installed at the GWRS project will reclaim 70 mgd.
Construction of the GWRS project began in early 2003. When completed, Phase 1 of the project will replace the conventional lime softening and RO system at Water Factory-21, which has injected potable quality reclaimed water into the coastal aquifers to prevent the ingress of seawater into the groundwater basin since 1976.
The GWRS is a project jointly sponsored by Orange County Water District and Orange County Sanitary District. Currently the OCWD supplies approximately 2.3 million people with water for drinking and household needs. However, the population is expected to increase to almost 3 million by 2020. The reclaimed water from the GWRS project will be stored in Orange County's groundwater basin either by injection along the coast or by percolation ponds near the Santa Ana River.
Low-pressure membranes have become the preferred technology to use for pretreatment to RO for treating wastewater for reuse applications. Compared to conventional RO pretreatment processes, low-pressure membranes offer many advantages. They occupy less space, typically need no chemical pretreatment other than pre-chlorination, are highly automated and less maintenance intensive, require less operator attention and dramatically improve the performance of the downstream RO.
