Straits Times 31 Oct 09;
More than a decade ago, eminent microbiologist Joan Rose, 55, was engaged by Singapore's national water agency PUB to head an external panel to assess the quality of Newater. Her contributions to Singapore's water industry will be recognised tomorrow, when she receives a Public Service Medal (Friends of Singapore) from President S R Nathan. Professor Rose speaks to Amresh Gunasingham about Singapore's reclaimed water and problems the world faces in getting safe drinking water.
# What sort of tests are performed to determine the quality of Newater?
They involve a series of chemical and microbiological tests for different things that can show up in water, such as nitrogen and phosphorus levels. The tests are, for the most part, quantitative, which means we can count what is coming into the sewer system, waste water plant and Newater facility, and what each barrier is providing in terms of producing a high water quality.
There are around 295 tests performed on Newater here on a variety of parameters. If you look at the yardstick used by the World Health Organisation (WHO) to judge the safety of drinking water around the world, then about 130 parameters are identified for testing. What Singapore did was look broadly and track new issues as they came to light globally.
We are pushing methods for detecting microbial contamination to lower and lower levels.
# Since its launch six years ago, what sort of improvements have been made to the quality of Newater?
The water quality has always been very high. The improvements have been made primarily in terms of operations and reliability and new technologies. For example, energy is a big issue facing the world, and waste water and drinking water industries are trying to understand how to produce high-quality water and be conscious of energy costs.
There are also new technological advancements such as the use of membranes of different sizes, which will have different capacities for producing water while giving a small carbon footprint.
# What are the emerging contaminants in water that experts are worried about?
Pathogens such as cryptosporidium have been at the top of the list of concerns due to their acute effects, including diarrhoea, and the list seems to be growing. Around the world, the presence of pharmaceutical products such as antibiotics and drugs that lower cholesterol in used water are of growing concern.
The authorities in Europe and the United States have started to investigate what hospitals and clinics do with some of their waste water and how pre-treatment could improve the approach to treating waste water, because we know a lot of drugs are used in hospitals.
Singapore has started to look at the list of pharmaceutical drugs that may be coming into the sewer system from the hospitals.
We have also encouraged the PUB to work with people in the health sector. It is a question of asking 'Who is using what drugs in Singapore?' because globally there is a list of different kinds of drugs that people use.
The WHO is currently grappling with determining what the health risks are for people, especially when dealing with pharmaceutical drugs. Nonetheless, a therapeutic dose is 10,000 times more than what can be found in water.
The multiple barriers in water treatment methods here mean we are able to reduce 99.9999 per cent of them.
# How is Newater perceived globally?
Around the world, it is called different things, but the process is similar in terms of the technology used to produce purified water. In Orange County, Southern California, for example, the authorities have been using a groundwater replenish system for some time. They are now developing a new facility fashioned to a large extent on what Singapore has done, where microfiltration and reverse osmosis are used.
There are also facilities in Africa which are reclaiming water for various uses, including domestic supply. Australia has also been looking at it seriously, having built a few treatment plants in Brisbane.
I think we are going to see a ramping up of Newater use globally, particularly in areas where they are thinking about scarcity, efficiency, conservation and water management.
