CAMBRIDGE, Massachusetts, April 29, 2009 — The 70 mgd Orange County Groundwater Replenishment (GWR) System, designed by the engineering firm CDM, recently won the Grand Conceptor Award in the 2009 American Council of Engineering Companies (ACEC) Engineering Excellence award competition. This groundbreaking $480 million project, which converts highly treated wastewater into an indirect potable water source, officially went online on January 25, 2008. The award was formally presented to CDM at the official ACEC awards gala on April 28, 2009.
Orange County Water District and Orange County Sanitation District hired CDM to design a solution that would meet an increased demand for potable water while minimizing the impact of extended area droughts. The expandable GWR System treats effluent with a multi-barrier approach — microfiltration for pretreatment, reverse osmosis for purification, and ultraviolet light for disinfection — removing bacteria, emerging contaminants, chemicals, and viruses.
Following treatment, the purified water is injected into an underground seawater barrier or percolated into aquifers before becoming part of the drinking water supply for the county's residents. This solution takes advantage of water that was formerly discharged into the ocean, helping to protect the environment and providing a new water source for the county.
As part of the project, CDM also designed supporting chemical systems, buildings, an electrical substation, three water pumping stations, more than 13 miles of transport pipeline, 3 miles of barrier pipelines, and 16 injection wells on eight different sites. CDM provided bidding support and construction services, operations and maintenance services, and assisted with operator training and facility startup.
This pioneering advanced water purification and groundwater replenishment system helps drought-proof Orange County while providing safe, potable water to a growing population in an environmentally friendly and energy-efficient way.