Start fifth 'national tap'

SINGAPORE - The current dry spell reminds us of the hard work national water agency PUB has put into planning and providing the country with reliable water sources.

Newater, desalinated water, water from local catchment areas and imported water are the four "national taps" of water supply.

Perhaps the PUB could consider a fifth tap - sea water, taking the cue from Gibraltar, which has a saltwater pipe system. The British territory uses the system for flushing toilets, firefighting, street cleaning and other sanitary purposes.

Most interestingly for Singapore, sea water is a valuable medium for heat exchangers, condensers and cooling towers.

At least one cooling plant in Singapore uses sea water exclusively for cooling. The advantage is that sea water requires very low energy for processing.

Many of our population centres are located near the coast, making the infrastructure cost of pumping sea water very affordable.

As the climate gets warmer, a lot more cooling capacity will be needed in Singapore. With good saltwater piping infrastructure, we can save a lot of energy in making Singapore a cooler place to live in.

This makes sense for businesses too. For example, the ice plant I work for requires hundreds of tonnes of brine each year. We are located just 100m from the coast, but we have to use precious potable water to fill up our brine tanks and import salt from India to turn it into saltwater.

Yang Ing Woei

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