The GWR System, a joint project of the Orange County Water District and the Orange County Sanitation District, was established in 1997 to preserve local groundwater resources and to help form Orange County Water District’s seawater intrusion barrier. Siemen’s 48 million-gallons-per-day (MGD) hollow fibre membrane system, coupled with an existing Siemens membrane system, will increase the flow to 134 MGD for the reverse osmosis (RO) membranes downstream in the GWR System.
 

Shivaji Deshmukh, GWR System program manager, Orange County Water District, said: “We were happy with the membrane technology in our existing system, and we felt that staying with this technology for the system expansion was the most efficient, cost-effective way to go.”
 

The RO pre-treatment system expansion will consist of Memcor CS membrane modules, ancillaries, control system upgrades, and associated electrical work. Siemens will supervise the membrane modules’ installation and the expanded system’s commissioning. Because the GWR System was designed for future expansion, with 20% extra space in the existing 26 basins, Orange County Water District will only have to add 10 more membrane basins.
 

Construction of the membrane treatment system from Siemens could begin in late 2010.