The Orange County Water District (OCWD), which manages a groundwater basin in Orange County, California, the United States, was awarded the Lee Kuan Yew Water Prize on Tuesday for its pioneering work in groundwater management and water reclamation using advanced water reuse technologies.

The award, which is the highlight of the Singapore International Water Week, also recognizes the achievements of the agency in public policy and community outreach, organizers said.

The OCWD piloted a water factory in the 1970s, which is believed to have been the first facility in the world to successfully produce potable-grade quality recycled water by treating used water effluent through an advanced water purification system relying on reverse osmosis and granular activated carbon. The reverse osmosis is similar to the technology Singapore currently uses to produce highly purified water from treated waste water.

Based on research and demonstration efforts by OCWD, a three- stage advanced treatment process of microfiltration, reverse osmosis and ultraviolet or hydrogen peroxide has been established as the standard for potable water reuse in the industry.

The agency launched a Groundwater Replenishment System (GWRS) in 2008 to replace the water factory. The reclaimed water is injected into a series of injection wells to create a hydraulic barrier that guards against seawater intrusion, preventing contamination of drinking water wells. It also provides a new source of high-quality water for year-round recharge to the aquifer.

The system is currently capable of supplying 265,000 cubic meters of water per day, which is enough to meet the needs of about 600,000 people. It is produced using half the energy required to pump water from other places. To date, the GWRS has produced 443,000 megaliters of water.

At the agency, an independent advisory panel was also set up comprising experts in various related fields from around the world, providing public confidence that various aspects of the projects have been independently and scientifically scrutinized.

The implementation model also involves extensive public outreach and engagement to pave the way for public acceptance of water recycling for indirect potable use. It has been replicated in countries such as Australia and Singapore as well as some other states in the United States.

Speaking at a press conference in Singapore, Michael Markus, general manager of the OCWD, said that the experience of his agency is especially relevant for modern urban environment where natural water resources are scarce.

The project is also economically viable as the cost of producing the water is only about one third of getting water from other regions. A tariff is charged on those who pump underground water.

Markus said that the Orange County Water District uses underground aquifer as it does not have reservoirs, whereas the Public Utilities Board (PUB), the national water agency of Singapore, uses surface reservoirs to store water resources for future use. Technically, an underground reservoir means less water lost from evaporation.

Public Utilities Board (PUB) Chief Executive Officer Chew Men Leong said that Singapore is also studying the possibility of developing an underground water storage system, but it is still at an early stage.

The OCWD will receive a 300,000 Singapore dollars prize, a certificate and a gold medallion at a ceremony held on June 2 during the Singapore International Water Week.

The Lee Kuan Yew Water Prize, named after Singapore's founding prime minister Lee Kuan Yew, was launched in 2008 to honor outstanding contributions by individuals or organizations towards solving the world's water problems by applying innovative technologies or implementing policies and programs which benefit humanity. The Singapore Millennium Foundation, a philanthropic body supported by Temasek Holdings, is the sponsor of the award.