Wednesday, January 13, 2010

Water trends in the next decade

As we come to the close of the first decade of the new millenium, it is time to do a bit of crystal ball gazing to find out what are in store for the next ten years.

1. Watershed and water quality management using GIS (geographic information system) and other tools
If you are not familiar with GIS (or confuse it with Genome Institute of Singapore), it is a computer database that incorporates geographical information (e.g. locations of petrol kiosks, water quality data) into a digital map. A good example of GIS is Google Earth though there are many other packages (both commercial and freeware) in the market.

With the aid of cheap GPS devices and telemetry, water quality sensors can be placed in strategic locations in a waterbody to provide continuous monitoring of the water quality. Data collected from these sensors can be transmitted via cellular/wireless/radio (aka telemetry) back to a remote server. These vast amount of data will need computing software such as GIS for interpretation into sensible and useful information. A polluting event can signal an immediate alert as monitoring is now continuous and no longer periodic (e.g. once a month). Manpower is also saved in such an arrangement as you do not need staff to go to the field regularly to take measurements. Staff are only mobilised to perform a more detailed investigation when an alert comes in from the remote sensors.

Figure: YSI buoy containing water quality and metereological sensors, telemetry package, solar panels and batteries (

One limitation of such a system is only certain parameters can be measured by sensors e.g. depth, dissolved oxygen (DO), turbidity, electrical conductivity (EC), temperature, pH, oxygen reduction potential (ORP), blue-green algae, chlorophyll, chloride, nitrate, ammonia. In general, these systems cannot measure phospate, bacterial count, heavy metals, pesticides, volatile organic carbon (VOC) etc. all of which exert significant impact on the water quality. (I am however sure that somewhere, somehow, someone is trying to develop continuous monitoring for these parameters.)

Figure: YSI water quality sensor package which can be installed on board YSI buoys. (
A parallel development in water quality monitoring is the use of remote sensing (aerial e.g. spectrographic imager; or satellite e.g. high-resolution imager) to gauge water quality in a watershed. These data can similarly be processed in a GIS. As you probably have guessed, remote sensing suffers the same weakness as telemetric monitoring - it can only assess a few parameters - turbidity, temperature, chlorophyll content etc., and in most cases less than those of telemetric monitoring.

Here is an example of remote sensing of coastal water quality by NOAA (National Oceanic and Atmospheric Administration).

2. Integration of energy and water

In the first place, water and energy are intimately linked. See

With the current emphasis on climate change mitigation, there is a trend towards greening everything by reducing energy usage, including water/wastewater treatment since much energy is needed to process water/wastewater e.g. desalination - reverse osmosis requires high pressures (and high energy input), distillation of seawater is an even bigger energy hog.

Solar energy will be increasingly tapped to power the treatment plant. This is in addition to other energy conservation measures such as green building design. Low technology options include creation of wetlands and reforestation in the plant's vicinity to sequester carbon dioxide. Colocation of power plant and desalination plant is increasingly being explored A power plant typically generates an obscene amount of warm cooling water (originally extracted from the sea) which discharges back into the sea. In colocation, the desalination can receive the warm seawater discharge as its feed, hence lowering the osmotic pressure to be overcome in reverse osmosis.

3. And in Singapore... increasing use of bugs (macroinvertebrates) for biological monitoring of water quality
Even though little has so far been publicised about this issue but the truth is lots of research is currently being carried out to use bugs for an integrated approach to water quality monitoring. In simple terms, the type and quantity of bugs in the water tell you about how good the water is. Obviously, work has to be done to develop useful sampling protocols and biotic indices relevant to this part of the world. Yes, I know USEPA ( and UK ( have very well established protocols and indices in place but are they applicable to Singapore or even Southeast Asia?

The strongest advantage of biological monitoring of bugs are:
  1. You do not need to test each and every chemical to check for pollution. Most chemical pollutants are inherently harmful to bugs so the type of bug community you get will indicate their presence.
  2. Unlike conventional monitoring of physical and chemical parameters, monitoring the bugs will reveal a pollution event has occurred, even though traces of the chemical pollutant have long since disappeared. Bugs will continue to display the effects of the pollutant for some time.
A major weakness...
Bug hunting is fun. Bug counting is NOT. Bringing a sediment sample back to the lab for sorting and counting of bugs can make one buggy. It is tedious and time consuming, causing the sorter/counter to enter a zombie-like state if done in excess.

Figure: Collection of bugs that is sure to thrill any student from primary to tertiary level.

Here are links to some of my bug hunting activities:

The above list is by no means comprehensive or exhaustive. They are what come to my mind based on my context and my experiences.

You may also read my interview on this topic in Straits Times (9 Jan 10).

No comments: