Siemens wins OC membrane system contract
A hollow-fiber membrane pretreatment system is to be supplied to Orange County's Groundwater Replenishment (GWR) system expansion under a US$ 14 million contract won by Siemens in California, USA.The 48 MGD (182,000 m³/d) membrane system, coupled with an existing Siemens membrane system, will increase the flow of to 134 MGD (507,000 m³/d) for the reverse osmosis (RO) membranes downstream in the GWR system. Construction could begin later this year.
"We were happy with the membrane technology in our existing system," says Shivaji Deshmukh, GWR system program manager, Orange County Water District (OCWD), "and we felt that staying with this technology for the system expansion was the most efficient, cost-effective way to go."
The reverse-osmosis (RO) pretreatment system expansion will consist of Memcor CS membrane modules, ancillaries, control system upgrades and associated electrical work. Siemens will supervise the membrane module installation and the expanded system commissioning.
At the time it was installed, the original Siemens membrane system was the largest membrane system in the Americas and one of the largest in the world. Because the system was designed for future expansion, with 20% extra space in the existing 26 basins, OCWD will only have to add ten more membrane basins.
The GWR system, which has been operating since January 2008, is the world's largest water purification project of its kind. Highly treated wastewater, originally destined for the ocean, is pre- treated by Memcor submerged membrane modules at a rate of 86 MGD (325,000 m³/d) before entering the RO units, followed by ultraviolet and hydrogen peroxide disinfection. The GWR system produces high quality water for less than the cost of future imported water, while using less energy and therefore fewer gas emissions.