Monica Kotwani Channel NewsAsia 18 Mar 14;
ORANGE COUNTY, California: Singapore's NEWater model of producing drinking water from used water is the result of much learning from California's Orange County Water District, which first started on it in the late 1990s.
Almost two decades on, Singapore's national water agency PUB said it is still relevant to look at the Lee Kuan Yew Water Prize winners for ways on utilising resources in an efficient and sustainable manner.
The Lee Kuan Yew Water Prize recognises individuals or organisations that use ground-breaking technology or innovative policies in solving water problems.
In arid California, it is a four-step process to give Orange County residents drinking water from used household water.
This includes filtering water through tens of thousands of fibre bundles to remove bacteria and other organisms, and exposing it to ultraviolet light for further purification.
This process is the final step in disinfecting and further purifying water.
The treatment process is similar to what PUB does at its NEWater plant to recycle water from households and light industries into drinking water.
But where NEWater is released into reservoirs, the Orange County Water District injects half of its recycled water into wells underground.
The pressure is enough to stop seawater from contaminating its current supply of groundwater.
The other water sources include water from the Santa Ana River.
It takes at least six months until the stored groundwater can be extracted again.
Michael Markus, general manager of Orange County Water District, said: "We're ground water managers. Our problem is -- this area is dependent on two outside sources of water.
"So over the years, it's become evident that we need to build local water supply reliability and that's why we built the Groundwater Replenishment System... so that we could have that reliable source of water that we can depend on, that we could replenish our aquifers which become part of our potable drinking water supply.
"It helps us become somewhat independent from those outside sources of water."
Harry Seah, chief technology officer of PUB, said: "In a way, the driver here is that instead of incurring so much energy to pump water across the Rocky (Mountains), Colorado, and then taking water from the north of California, where it's long distance, looking at this project helps us to understand that we also need to utilise our own resources efficiently and in a sustainable way of managing the system -- so that in the end, you can have good, affordable water."
While it is still at an early stage, PUB said it is also looking at the California agency's water management system as it embarks on its own groundwater journey.
- CNA/de
