Sunday, March 29, 2015

Enough clean water for my children and their children - remembering Mr Lee Kuan Yew (LKY)

This week (23 - 29 Mar 2015) marks the mourning of the passing of our first prime minister, Mr Lee Kuan Yew (LKY), widely recognised as Singapore's founding father.

As I was going through the historical documentaries of the man shown continuously on TV, I was reminded of his contributions to the water supply in Singapore. The early years of Singapore (1960s, 70s) were trying times. Massive issues had to be resolved right there and then - housing, education, healthcare, security, jobs and of course water and sanitation. It was mind boggling to contemplate these issues all together, much less come up with workable solutions.

Anyone familiar with human nature should realise that once the basic human needs (e.g. food, water, shelter) are not met or disrupted, you are going to have lots of trouble on your hands. Think about looting, rioting and general social unrest - just look at Chile, Haiti after earthquakes. I am sure there are many more such examples if you google them up.

No, in the chaotic situation that is Singapore in the 1960s, water needs must be effectively addressed. (Sanitation too as I believe water and sanitation are merely 2 sides of the same coin hence the term, watsan but sanitation is a story for another day.)
'In 1963, just a few years after its self-governance was declared, Singapore experienced a severe drought. This harsh experience left a deep mark on the population. As the Prime Minister of Singapore at that time, Mr Lee Kuan Yew was determined to drive Singapore towards water sustainability. This, he did by making water a top priority in government policies. "This [water] dominated every other policy. Every other policy had to bend at the knees for water survival."'

In those early days, LKY already realised that there would not be enough water given the paces of development and population increase. Water from reservoirs and from Malaysia were not going to make it. (Only MacRitchie, Pierce, Seletar and Fort Canning (for the port) were operational as of 1963. Source: PUB) (As of the 1960s, the very first agreement signed in 1927 was no longer in force. 2 others - 1 signed in 1961, another one in 1962, were then operational. Source: Singapore Infopedia)

Looking at the scene now (2015), I am quite pleased to see the 4 National Taps operating - local catchment, imported water, Newater, desalted water. By 2060,
  • Total local catchment area will have increased from the current 2/3 to 90% of surface area (see previous post related to this topic)
    "Currently, NEWater meets up to 30% of the nation’s current water needs. By 2060, we plan to triple the current NEWater capacity so that NEWater can meet up to 55% of our future water demand."
    "Today, desalinated water can meet up to 25% of Singapore’s current water demand. The plan is to grow Singapore’s desalination capacity, so that the Fourth National Tap will be able to meet up to 25% of our future water demand by 2060."
  • What is so special about 2060?
    "Beyond 2061The Singapore government has stated that it will not renew the 1961 agreement which expires in 2011. Attempts to reach a new deal with Malaysia to secure water supply for Singapore beyond 2061 have not borne fruit despite years of tedious negotiations. To reduce Singapore's dependence on imported water, the government has taken steps to increase the size of the local water catchment area and to build up the supply from non-conventional sources, namely NEWater (reclaimed water) and desalinated water. With the various water projects progressing well, government officials have assured Singaporeans that the country can be self-reliant in water by 2061 if it needs to be."

    Yup, so that is it. The last 20% will be served by local catchment by 2060.
With such forward planning, I feel assured that the water needs of the country and my family will be well met...

But... (there's always a but) all these come at a price. Newater and desalted water are not cheap to produce. Requiring sophisticated reverse osmosis units using easily fouled membranes, they basically involve passing contaminated water through a filter that removes the contaminants. Imagine a filter with really small holes that only allow water molecules to go through. Even small stuff like salts and oils are retained on the filter. This is going to use lots of pressure to push the water through and  associated with it are high energy usage and costs.
"The first year (2003) tender price for NEWater from Singapore's Ulu Pandan plant was S$0.30/m3, which is significantly less than the cost of desalinated water. The selling price of NEWater is S$1.15/m3, which covers production, transmission and distribution costs."

"The cost of the desalinated water during its first year (2005) of operation was S$0.78/cubic metres."

Desalted water is naturally more expensive to produce than Newater because seawater is much more saltier ("contaminated") than normal wastewater in our sewers. As such, you need much higher pressure (translated into energy and cost) to filter off the salt in seawater.

In contrast, the production cost of tap water should be in cents/m3 (sorry, can't find a good source for this figure. I picked it up when I studied about reverse osmosis in university.)  

Finally, don't forget that to ensure water security for our small nation, energy security is a co-requisite. Without natural gas, biofuel or whatever to generate electricity, desalination and Newater production will be adversely affected.

Thursday, March 26, 2015

The curse on the waters off Pasir Ris

The waters off Pasir Ris seem destined to be cursed with massive fish kills now and then. Fish kills have been documented there for years! (See my previous posts on this topic.) The latest came as no surprise - Straits Times 1, 2; Today 3, 4; Channel News Asia (CNA) 5.

In response to an invitation from CNA to check out the waters there, a team of us headed down to the field for a quick water quality monitoring (WQM). It had been a week since the fish kill occurred so I was not expecting to see anything extraordinary in our WQM results. Nevertheless, it was a good chance to stretch those hands and legs on some good old field work.

Other than conducting field trips for my students as part of their curriculum, it has been some time since I have field work in WQM. For those following my blog, I had been involved in other aspects of water the past few years - rainwater harvesting, grey water recycling. Water is such a fascinating yet vast topic. It can cover indoors, outdoors, natural, industrial, agricultural, household, economics, political, war and many other areas besides.

Back to Pasir Ris... On 10 Mar 2015, we did WQ tests at 2 spots at Pasir Ris and 1 spot at Punggol for reference. Here is a summary of the results.

The number above may appear intimidating but worry not, below is a description in plain English.

Overall, the water quality looked pretty good for all 3 locations. A few points:

1.       The water at Pasir Ris has become somewhat saltier compared to my data in 2010.

2.       The water has also become somewhat more alkaline compared to my data in 2010.

3.       The water is significantly clearer (less turbid) compared to 2010. Less construction work going on?

4.       Nutrients (ammonia, nitrate, phosphate) are significantly less compared to 2010.

5.       Bacterial counts are significantly less compared to 2010. Can we all swim there now?

6.       Pasir Ris spot 1 appeared to have a slightly higher bacterial count compared to the other 2 locations. FYI, spot 1 is where a great deal of dead fish were washed up the previous week.

 Don't forget, about a week has passed since the fish kill. Don't expect to see problems in the water quality during our field trip or we will still be seeing dead fish on the shores for the entire week - a scary thought.

Figure: WQM team at work at Pasir Ris

Figure: The cozy CNA van that brought us and our equipment around our test sites

Tuesday, March 17, 2015

Fluoride and other contaminants in beer

Hi there,

I've browsed your blog many occasions and always found it a good read, irregardless of whether it answered a question I had at that point in time. 

A bit of background - Water is something key to my interests, as I have grown up with freshwater fish and currently have become a brewer(of beer). Therefore chemistry and quality of the local liquor has always concerned me. 

I have recently installed a water filtration system at home with activated alumina - with the intention of removing fluoride. Would you have any advice on where I could get a water test done up? Key substances would be chlorine, chloramine and fluoride. Also, I'd be open if you have other advice to share.

Best regards,

Hi E,

Thanks for sharing your interests and your thoughts on my blog.

You have touched on one of those controversial and hotly debated health topics in water and food - fluoride. Fluoridation of drinking water was initially touted as beneficial to the protection of teeth against decay. Over the years, studies have shown that an excessive amount of fluoride in our bodies can lead to fluorosis which affects the teeth and bones adversely. The irony is not lost to most people aware of this issue - too little fluoride, you get tooth decay; too much, you get teeth damage.

More about fluorosis in this WHO (World Health Organisation) page or feel free to google up yourself:
"The dental effects of fluorosis develop much earlier than the skeletal effects in people exposed to large amounts of fluoride. Clinical dental fluorosis is characterized by staining and pitting of the teeth. In more severe cases all the enamel may be damaged.

Chronic high-level exposure to fluoride can lead to skeletal fluorosis. In skeletal fluorosis, fluoride accumulates in the bone progressively over many years. The early symptoms of skeletal fluorosis, include stiffness and pain in the joints. In severe cases, the bone structure may change and ligaments may calcify, with resulting impairment of muscles and pain."

Naturally, one BIG question is what constitutes an excessive amount. Remember, our intake of fluoride includes the food we eat too. There are already arguments against fluoridation of drinking water since it is claimed that the dosage from our food is already enough to fight tooth decay. According to the drinking water guidelines from WHO, the limit of fluoride stands at 1.5ppm (parts per million). And based on the Singapore Drinking Water Quality Report 2014 from  PUB, our drinking water has an average of 0.48ppm and a range of 0.40-0.62ppm fluoride.

For people concerned about fluoride, filters containing activated alumina have been well known to remove fluoride. Back to answering E's question, my concern is given the already low level of fluoride in Singapore tap water (see previous post, Evaluating the necessity and usefulness of water filters for domestic tap water for an idea), how effective is your filter in removing fluoride? I was going to ask whether there is a need to remove the already low levels of fluoride but since you have already installed the filter, this question is moot. :-)

If your intention to test for fluoride, chlorine and chloramine is one-off, then you can approach a commercial testing lab. The ones I know are (in no particular order):
  1. Tuv Sud PSB
  2. SGS Testing
  3. Setsco Services
  4. CPG Laboratories
If you only have one water sample to test, I believe your tests should not cost more than a hundred dollars. BUT very importantly, do find out the detection limits for their tests. If the test results show zero, they simply mean that that particular contaminant is NOT DETECTED rather than totally absent.

On the other hand, if you intend to conduct these water quality tests on a long term basis, you may want to consider getting a test kit such as the Checkit Comparator from Aqualytic. The Local distributor is Quantum Technologies Global Pte Ltd. It is designed to test for fluoride from 0.2-2ppm. I feel that this should be enough for your purpose. To detect any lower concentration will require more complicated (and expensive) instruments normally found in a lab. And frankly, I am sceptical that there is a need to reduce the fluoride concentration any lower for beer. Not to mention that it may not be economical to do so - you will need technology more advanced than filters to achieve that low a level.

Similarly, the Checkit Comparator can also test for chlorine (free chlorine ) and chloramines (combined chlorine). But do note that each of these tests require the use of different chemicals. Please be careful about storage, handling and disposal. Wear protective gear and make sure other people are not unnecessarily exposed, especially children.

Figure: Aqualytic Checkit Comparator. Different coloured discs are used for different tests. The above discs are for nitrate (pink), ammonia (green), phosphate (blue).

Saturday, June 28, 2014

Rainwater harvesting in HDB flats? Check out Treelodge @ Punggol

I had the privilege of given a tour of Treelodge @ Punggol by HDB staff some time back. The tour includes a sneak review of the various green implements on the rooftop (normally locked from the public) of this housing development.

Of particular interest to me is the rainwater harvesting system. Some highlights:
  1. Rainwater is harvested from the rooftop, treated and channelled into storage tanks at the top level.
  2. Grating is installed at inlets on the rooftop to remove large contaminants e.g. leaves, litter
  3. The system is designed to make use of gravity to minimise pumping.
  4. A first flush system is used to remove the first portion of each rainfall event. (As mentioned in my previous posts (1, 2), a first flush device or system is absolutely essential to remove the initial and dirtiest portion of rainwater.)
  5. The treatment of rainwater involves something called DPA system or technology.
    • "proprietary technology which harness on the works of Hydrocavitation, where liquid is subject to forces of fluctuating pressures within the enclaves of its cavitational chamber, is a chemical-free water treatment process.
    • DPA system is effective in controlling pH levels, increasing dissolved oxygen and significantly reducing bacterial and algae growth in the water."
    • Installed by a company called Sif Eco Engineering Asia. Tried to visit its website at but ended up at a page under construction so I don't know anything more about this company. 
  6. Not surprisingly, the treated rainwater is only used for:
    • Washing of staircases, void decks, corridors
    • Irrigation
  7. Obviously, potable use of the treated water is out of the question. Neither is it used for toilet flushing.
  8. No mention of how successful the system is but I don't think there are any problems. Rainwater is one of the cleanest forms of water.
Figure: Garden beds on the rooftop. Nice touch. Cool the top levels?

Figure: Experimental wind turbine. In Singapore, you have to go high for wind turbines to capture the energy of the stronger winds.

Figure: Photovoltaic (PV) panels on the rooftop to provide extra juice to power consumption in the common areas

Figure: Explanatory panel on the rainwater harvesting system. Unfortunately, this panel is on the rooftop so the public normally does not read it. Not sure if there are similar panels in the accessible areas.

Figure: Notice the grating inlet fixed into the floor (rooftop). It is designed to filter off the gross (in size) contaminants in the rainwater. Also, notice the small white pipes jutting out of the garden beds. The plants probably help to clean up the rainwater a bit before channelling it to the inlet.

Figure: Treelodge @ Punggol

Sunday, June 22, 2014

Advice on purchasing water testing kit for JCU Singapore

I found your blog online whilst looking for water testing equipment. I hope you don't mind me contacting you! 

I am a sessional lecturer at JCU Singapore and teach a first year subject called Environmental Processes and Global Change. It is essentially an introductory amalgam of geography and ecology. I take my students on at least two field trips (and a 3rd if we have time and the weather is kind to us!) Last year, for one trip, we went around the corner to Bishan Park to do a number of activities, including water quality testing. The kit I used was borrowed from (removed by blog owner) and was really far too basic for our needs (although none of the students had ever done ANY field work before so it was still fun). I would like to order a kit for the department (we don't have one yet), preferably one that has a number of options and could be used for other subjects (e.g., marine science, aquaculture etc). 

Do you know of a brand / local supplier you could recommend? Ideally it would be robust (come in a lightweight case) and give accurate enough data to compare DO, pH, salinity, temp etc between locations. I have found a kit online from a company based at Ubi Ave (, but would appreciate any recommendations or advice before I go any further!

It would be nice to touch base with you anyway, as it seems we may be teaching similar subjects.

Kind Regards,

Hi M,

Glad to see that you bring your students for field trips. I always believe that our students don't go out of their classroom enough. There are of course logistics and safety to be concerned with but something suitable can usually arranged.

Previously, I minimise mentioning about companies, brands and models as I don't want to be seen to be endorsing them. However, there had been many requests from my readers to recommend vendors and equipment to them, whether for water filtration, water quality monitoring (WQM) or water engineering. I realise that I am doing a disservice to you by withholding such information.

But first my caveat: throughout my blog, any recommendation of companies, brands, models is purely based on my experience and knowledge. Unless stated explicitly, I am in no way affiliated to them and derive no benefits from recommending them.

You may want to read my book "Your first guide to water quality monitoring in Singapore" for a description of the WQM equipment that I have used. It is available online free at PUB's website.

There are actually many distributors of many brands of water testing equipment in Singapore but the following are the few I have worked with and feel comfortable enough to recommend.
  1. Most of the equipment comes from the brand, Aqualytic. Local distributor is Quantum Technologies Global Pte Ltd.
  2. The Hach series of products (including test strips) is also very good as it is a very established supplier in the area of water testing. Local distributor is Fluke South East Asia Pte Ltd.
  3. The YSI brand is also very reputable and their products are usually designed tough for field work. One distributor is Spectra-Teknik.
I am not sure about bksna as I have never used their equipment before or heard any reviews about them. Still, you can go ahead to check out their specs and prices and compare to the others above.

Good luck!

Saturday, June 21, 2014

Water quality of wetlands - Sengkang Floating Wetland

My name is J, and I am an undergraduate studying Environmental Studies in NUS. I will be starting on my honors thesis with my professor Dr. L this coming semester, and it is based on water quality monitoring at constructed wetlands-Sengkang Floatingwetland and Lorong Halus wetland. I have been reading your blog, and it has a lot of wonderful information very useful to me. I am still in the midst of my research before I start fieldwork, and I would like to ask you a few questions.

1. What are the parameters that you have measured in these wetlands before, and is it possible for me to obtain the data of these parameters? Considering the fact that I will be conducting some tests, a comparison with previous records of your data would be very useful.

2. Also, have you done a dissolved carbon analysis of the waters in Singapore/pCO2 analysis?

Thank you very much Sir!


Hi J,

Glad that you like my posts. And I am happy to see that you are doing some field work at Sengkang Floating Wetland and Lorong Halus Wetland. I feel that not enough is being done to monitor the water quality in our water bodies.

1) I have not done any monitoring at Lorong Halus.

As for Sengkang Floating Wetland, I have conducted a workshop for teachers (1, 2) there in collaboration with PUB. No data was officially documented as that was a training workshop rather than a scientific monitoring session. But I have dug up a photo of the white board when the participants presented their results. See if you can make sense of it.

Figure: Results of water quality monitoring workshop at Sengkang Floating Wetland (11 Nov 2011)
2) No, I have not a dissolved carbon/ pCO2 analysis. My choice of parameters in water bodies is determined more by the demands of a healthy ecology. (Naturally, if I am working with drinking water or wastewater, the demands and thus parameters will be different.) In my opinion, dissolved carbon/ pCO2 are indirect parameters when it comes to water ecology as they reflect the interactions of water and geology more.  There are already so many parameters to monitor. No need to complicate matters or use up more resources unnecessarily :-)
Good luck!

Friday, June 20, 2014

More questions on the British Berkefeld (BB) (Doulton/ Berkey) Water Filter

I'm not really knowledgeable about water. I'm wondering if you could give your opinion about some question I have.

1) Do you use this filter at home or another filter? If another kind, why?

2) I'm thinking of getting a small one for myself as I don't think the water I get from the tap (even though I boil it) is healthy. Do you have any thoughts on that? I'm sure using the filter would ensure the water is better right than just drinking boiled tap water in Singapore right?

3) There are so many other kinds of filters or water products, etc. - Kangen that gives alkaline water, Diamond, etc. How do you think the Berkefeld compares to the rest?

Also, if I get the Berkefeld, I heard some people say that I should get the arsenic and flouride filter too. I think that was from people in America getting the Berkey brand (according to you, both are the same right?) Are those additional filters necessary and available from Arkwater?


Hi J,

Sorry for the delay in replying.

You may want to check out my previous posts on water filters/purifiers as I have touched in depth on the answers to some of your questions. In particular, please read the post on "Testing your drinking water - the whys and why nots".

Before I go further, let me reemphasise that throughout my blog, any recommendation of companies, brands, models is purely based on my experience and knowledge. Unless stated explicitly, I am in no way affiliated to them and derive no benefits from recommending them.)

Now, to answer your questions:

1) No, I don't regularly use any sort of filter at home. Most of the filters mentioned in my blog are part of my academic endeavours (aka projects). The exceptions are the small portable ones e.g. Katadyn Mini for my personal use outdoors. (Hey, even if the virgin jungle streams are supposed to be free of pollutants, I very much prefer to at least boil or filter the stream water. Nevertheless I have drunk straight from the stream without ill effects. Not something I recommend but it has been done.)

Oh, back to your question... Despite the shortcomings of the WHO drinking water guidelines and the controversies surrounding chlorination and fluoridation of drinking water, I still believe PUB is doing a good job of ensuring safe drinking water in Singapore. Not taking things at face value, I have done various tests on tap water over the years. Though nowhere as extensively done as PUB (I frankly don't have the resources that it has), the results generally agree with the claims by PUB on compliance to or even surpassing WHO guidelines.

Then why am I talking about the BB filter at all? Because, it is a valuable item to have around during emergencies when the quality of your water supply is suspect. That is, if you have any water coming out of your tap at all. Check out the disasters in Chile, Haiti, Pakistan, New Zealand and I am sure in many other countries too on the status of their water supply after a bad dose of earthquake, storm or flood.

And for those who venture to developing countries to do OCS (overseas community service), a BB filter is invaluable in areas with unknown water quality unless you enjoy bottled water for 2 weeks or more.

2) Again, please read my earlier posts on water filters/purifiers. In short, Singapore tap water is already very clean so a water filter will find itself hard pressed to clean the tap water further. Any removal of contaminants will likely be marginal. Unless you are prepared to go a big step up to the next level of water distillers, reverse osmosis (RO) or air-to-water devices. These machines are generally expensive at the outset and also in terms of the power they suck up. RO involves the replacement of the RO membrane modules which are not exactly cheap, partly because most of them are proprietary for your particular make and model. 

However, having said the above, psychology is a powerful factor to consider. If you feel that a water filter can ensure your good health, do go ahead to install one. Furthermore, many health issues regarding drinking water are controversial. Heck, who knows, some of them may be proven right in the future. E.g. chemical X is indeed bad for your health... you mean you have consuming it all your life... oppps.

Ultimately, what I am saying is if you indeed make a purchase, know why you are doing so. It should not be based on blind fear or unsubstantiated rumours or worse, unscrupulous sales tactics by a water filter supplier.

Think about the "whys" in buying a water filter. Are you worried about a particular chemical(s)? If so, is it at a significant level in your tap water? If it is, can your filter really remove it effectively? Not sure? How about this: before your buy, ask the supplier to let you run a real water sample through the filter and send the input and output samples to a certified lab for testing of that particular chemical? I am not sure if the supplier will agree but it is worth a try.

3) I shall not comment much on alkaline water at this point except to say that I prefer to remove contaminants from water rather than try to add something (alkali) (a contaminant?) into my drinking water. Something which is still controversial in its health claims and that complicates matters unnecessarily.

4) Arsenic is not a problem in Singapore. It is a big and dangerous problem when groundwater (well water) is used e.g. Bangladesh and parts of USA.

Fluoride in water is still a controversial topic. You can find out more about fluorosis in Internet. I believe the fluoride removal element from Arkwater needs to be connected to your pressurised water supply (i.e. tap) to work. It doesn't work well with gravity flow. Something to take note of if you decide to get it.

Good luck!

Figure: BB filter big enough for a family. There are smaller and bigger versions too.

Figure: My Katadyn Mini. Small and handy. Useful for the outdoors. Has a capacity of 7000 litres per filter element. Unfortunately, it can only remove particles and microbes of bacterial size and above. Not so effective against viruses and chemicals.

Figure: Inside a BB filter housing - 3 filter elements (or candles) to allow a reasonable throughput for a family