Corporate Social Responsibility (CSR) in Batam: Solving issues in water shortage

Due to ongoing business discussion, I have left out names of the parties involved and certain details that can impact business decisions.


I got a rare chance to tag along with this water company (referred to as the company) to Batam to evaluate the water issues facing a holiday resort and a couple of nearby villages. This is not your typical urban resort as it is located faraway from the island's centre.


Issues

1. The resort was concerned about the (in)adequacies of its current water storage and treatment set-up. Though nothing adverse has happened (yet), it decided to pre-empt any problems by engaging the company to check out its set-up anyway.
2. 2 small villages on different islands. 1 with about 20+ residents, the other with about 80+ residents. No water issues for most part of the year except when the drought comes in. This drought can last for 3-4 months, enough to run the springs and wells dry.
3. One pre-survey suggestion thrown up was the use of rainwater harvesting. We also evaluated the feasibility of implementing RWH there.

I will not present the proposed solutions here as they are still undergoing business discussion. Instead, I will highlight some of the interesting observations during our survey.


A couple of personal observations: Perhaps due to the nature of the company's business, grey water recycling/use and sanitation were not considered as part of the solution, though in my opinion, these can be relevant factors to close the water usage loop.

Figure: Partially covered spring serving the resort's water needs. I just thought that it ought to be better covered to prevent animals from accessing it.

Figure: Water from the spring is pumped uphill to be stored in these tanks. Notice 1 line allows water to enter the tanks, the other line to transfer the water to the resort downhill by gravity.

Figure: Closer view of the water tanks. The larger ones have a capacity of about 1000L each.

Figure: Typical well serving the villages. There are several of these. Typically not covered. Clarity ranges from clear to slightly turbid

Figure: Washing and bathing using the more turbid water. Clear water is reserved for drinking.

Figure: the watering hole providing turbid water for non-potable purposes

Figure: Perhaps the villages are not as poor as what we initially thought. Common sight of solar panels and TV antennae

Figure: Nothing to do with water issues, just too nice to leave out. The sea at dawn

Figure: If there is one thing I learned, it is the importance of geography to water issues. Climate, topography, vegetation, geology affect the quantity and quality of water. View from the highest point of 1 of the islands.

Not your everyday water filtration unit: Community scale emergency water filtration

I have been writing about getting water in emergencies for a while.

1. Flooding in Queensland, Australia (2011): mad rush to buy food, water and other essentials
2. Earthquake in Chile (2010): mad rush to loot food, water and other essentials
3. Earthquake in Haiti (2010): looting; relief agencies provide water
4. Others - Pakistan, New Zealand and use of British Berkefeld filter
5. Use of Sawyer mini filter in an emergency

But in this post, I will focus on the production of potable water on a community scale in response to a disaster. This is based on my recent training experience with Indonesian Red Cross (aka Palang Merah Indonesia (PMI)) in Indonesia of course. As the country is a disaster magnet, PMI has become very adept at disaster management, including providing WASH (water, sanitation & hygiene) services.


PMI's current favourite water filtration unit is the French LMS system. Light (relatively as you still need 4 guys to carry a single filter), compact, modular - what's not to like about it? Especially when it can be freighted anywhere easily and deployed in 30min by a trained crew.

Figure: Water Distribution device for the end users (aka beneficiaries affected by the disaster). Anyone feel like "milking these cows"?

Figure: The engine/pump to suck in the raw water for treatment. BTW, there was no maid to help you get this working. You have to get your hands dirty to prep everything yourself. Remember the 3Fs - fuel, fluid (engine oil), fire (spark plug) and make sure all 3 are in good order before starting up.

Figure: The activated carbon (AC) filter which needs 4 guys to carry around. Together with the sand filter (similar weight), they are rated to produce 4000L/h of water. This translates to enough water for 6400 beneficiaries assuming the system is working at full capacity and we are following Sphere standard of 15L of water per person per day. Hidden behind the main drum is a chlorinator (black box).

Figure: Sand filter. This has to come before the AC filter.

Figure: Trying to join everything together. Notice the 1000-L water bladder (in yellow) in the foreground. It is supposed to store the treated water before heading to the distribution device.

Figure: Using a pool tester to check the chlorine residual and pH in the water. Together with turbidity, these 3 water quality parameters are the most commonly tested in such a scenario.



Figure: Very important! Everyone involved in setting up the filtration system must be on the same page (literally and figuratively) on where every component is placed. This layout sketch was used in our briefing and walkabout before everyone rushed off to their respective tasks.

My after-action thoughts

1. I thought it would have been good to include an electrical conductivity (EC) meter to check the raw water. If its salinity was too high (> 2500uS/cm according to PMI standards), we would have sought an alternative water source instead of committing our efforts and time to set up the system only to get a salty tasting end product.
2. Though not obvious in the photos, 2 chambers with attached mixers were used for coagulation and flocculation, respectively. We were provided with coagulation tablets (1 aluminium based and 1 iron based) and flocculation tablets (1 cationic polymer and 1 anionic polymer). Unfortunately, the instructions on their dosage were not clear i.e. how much to add under what conditions.
3. No head/pressure calculations were done on the set-up. Perhaps too engineering for most people, it is still a good idea to know at least the maximum allowable suction lift (water source to pump) and elevation (pump to bladder). I certainly do not want to set up everything (we took less than an hour by the way) only to find not a single drop of water coming out in the bladder due to insufficient pressure provided by the pump.
4. Not enough info on our water source - a pond within a fenced compound. I was rather concerned about the presence of ammonia (human waste, fertilisers from nearby?) and to a lesser extent, nitrate (anyone using fertilisers?). Some simple test strips should give us an answer but we did not have these available.
5. What about solvents, petrochemicals, pesticides, heavy metals AND pathogens? Don't we have to check for them too? Admittedly, all the above contaminants are serious concerns but testing them in the field is impractical. Either they need sophisticated equipment requiring electrical power or they require specialised lab skills. And some require time e.g. bacteria count needs incubation of 24-28h, time which is usually lacking in a real emergency scenario.
   
   Therefore, we have (hope?) to rely on our coagulation/flocculation, sand filtration, activated carbon and chlorination to remove them sufficiently in the final product.

Figure: My favourite EC meter. Durable and simple to use. Though it does not measure seawater, it is good enough for most purposes.

Figure: Hach test strips for nitrate and nitrite. Also simple to use in the field

Figure: Hach test strips for ammonia. Ditto.

My greatest challenge in providing water at community level


Guess what? The most challenging problem has nothing to do with the technical aspects of the water system. And if you guess it is the human factor, you are absolutely right!


But before you start speculating about internal problems in our team, that is not it! Teamwork was great and I could not have wished for a better team.


Instead, before the actual deployment, we had to perform a needs analysis of the community, a survey of sorts on our beneficiaries. Though we were not in a real disaster, we did a survey of the villagers in the area as part of our training. They spoke Sunda, an Indonesian dialect and of course Bahasa. I certainly could not speak Sunda and my Bahasa is sikit sikit (little little). Fortunately, our survey team leader could converse in Malay (quite similar to Indonesian Bahasa) and that made all the difference. He could build the rapport needed for us to obtain valuable data about how the villagers manage their water, sanitation and hygiene.


To me, the language barrier is a very real problem for community scale emergency water filtration.

Figure: Not your grandfather's car. This Landrover was used in carrying ALL our equipment (including water filters) into the village for deployment. Like the Energizer Bunny, it never stops, accomplishing the toughest jobs despite its beat-up appearance.

Figure: Deployment ground within the village. Note the picturesque scenery in the background

Revisiting rainwater harvesting in Singapore

Hi there,

 

I came across your blog when I was doing some research on rainwater harvesting systems (we are in the process of renovating an old inter-terrace house that that we just bought, and thought that this might be worth exploring).

 

I know that this is a question that you fielded a number of years ago (hopefully things have changed since then, as your answer then was that there wasn't much demand for this), but would you know what is available in the market in Singapore in terms of rainwater harvesting systems for domestic households (we are looking for a fairly straightforward above-ground system) and are there any that you recommend? 

 

Thank you,

 

Felix

Dear Felix,

Indeed, the rainwater harvesting (RWH) market appears to have developed in the past few years. I believe RWH is becoming more widely known and accepted in SG. That comes with a rise in demand for RWH and naturally, businesses will be built around servicing this demand.

I am actually happy to see this happening as it shows that people are becoming green not just in words but in action too. However, we also have to bear in mind that the current RWH solutions in the market are more geared towards a private house rather than a HDB flat. (On the other hand, RWH can be done at community level by e.g. HDB at Treelodge@Punggol in which the whole HDB estate is designed and built for RWH.)

Over the past years, I have come into contact with some of these businesses. A quick online search should yield the same results.

1. Green Eco Harvesting
   A quick glance shows that it is offering tanks and filters for RWH
2. Netatech
   It advertises construction of RWH system.
3. Hydro
   It features tanks and filters for RWH.

As for your question, no, I have no preference for the above or any other vendors. But if you decide to go ahead to integrate a RWH system into your house, a few points to keep in mind...

1. Does the vendor only sell you the tank & filter or does it include installation into your existing house structure?
2. What kind of maintenance is needed for your RWH system? Does the vendor offer such a service or are you on your own after its installation? Obviously, the cost and frequency of maintenance should be taken in consideration when you make your decision to get a RWH system.
3. Is your setup legal??? Legally speaking, the plans for your RWH setup have to be approved by PUB and NEA (if gutters are involved in RW collection). These plans are typically submitted by a QP/PE/architect to the authorities. Is the vendor doing these for you or are you expected to engage your own QP/PE/architect to do so? Finally, legal means additional costs so factor that in too!

Good luck!

Figure: using a zinc roof to collect rainwater (Water for Life, Hesperian Foundation)
Who says RWH has to be complicated? It has been and still is done simply and cheaply in developing countries. Mosquito breeding is a concern but not insurmountable with care and effort.

Ok, water from the water treatment plant is clean... do I still need water filters?

Dear CK,

I have read below 2 articles with great interest and I like your logical reasoning very much.

http://waterqualityinsingapore.blogspot.sg/2015/04/why-i-wouldnt-be-drinking-alkaline-aka.html
http://waterqualityinsingapore.blogspot.sg/search/label/water%20filter%2Fpurifier

I understand that water level in Singapore is clean and that PUB has exceeded WHO guidelines. However, I have one further question in regards to the need of water filter for home.

The water is clean at PUB treatment plant. But the water will need to pass through the pipes before reaching our home. We do not know when was main pipe in the ground was last changed? For sure, the small pipe leading to our home is as old as the building which we live in.

Please note that I am not affiliated with any water filter companies. I just want to learn more as I am thinking of purchasing a water filter system to clean the water at final stage before boiling and drinking.

I look forward to your advice. Thank you very much.

Best Regards,
KH


Dear KH,

Thank you for enjoying my writing style. I always prefer to keep things simple, straight to the point and free of unnecessary technical jargon, with some humour (dark or otherwise) thrown in if possible. Naturally, some technical terms are unavoidable since water itself is a technical subject.

You are absolutely right. Water straight out of water treatment plants is definitely within specs. The question is what happens in between the outlet of the plant and faucet in your house? We are talking about miles and miles of piping, pumps, valves, tanks.

And if you look at the figure below, we are also talking about third parties like town councils and building management committees  (BMC) sharing in the responsibility of providing you with nice, clean water. (Also, note where the responsibility of one party ends and the other begins.)


Source: http://wildsingaporenews.blogspot.sg/2009/07/brown-tap-water-still-safe-for-drinking.html#.Vp8I6RHVxjo

Anyway, the same question has been raised before in the media in Jul 2009. Do go through it as some interesting points had been put forth, accompanied by equally interesting answers from PUB, a concerned expatriate, a doctor and others.

1. In case you did no go through the above articles, I will summarise their contents here. In a nutshell, yes, contaminants can enter your tap water along its tortuous journey. Assuming PUB is doing its job well of maintaining its extensive distribution network (no reason to assume otherwise), it boils down to how well your town council or BMC is doing its job in maintaining its piping and tanks.
2. Barring unexpected incidents like finding a dead maid in the water tank, by regulation:
   "Management corporations and town councils must engage a licensed water service plumber at least once a year to inspect and, where necessary, clean and disinfect their water tanks and certify that the tanks are fit for drinking water storage."
3. The most common culprit in your tap water is rust (an iron compound by the way) silt. It comes from the corrosion of iron piping, especially older piping. It can be visible in water or seen on your filter elements. PUB maintains that this is harmless.
4. The recommendation is to run your tap till the water becomes clear. Then you take that water for consumption. (Whatever the case, whether iron or other contaminants, this is my recommendation too! Especially in the morning when water has remained stagnant in your piping for long hours during the night. Stuff, if any, from your pipes tend to leach into your water during this time.)
5. Finally, though the last portion of the water distribution system is not under PUB's jurisdiction, you can call it up if you suspect anything amiss in your tap water.

Regarding the last point, PUB will typically send a technician down to take a sample of your tap water back for testing. The test result will come back as either the water is in compliance or out of specs. Don't expect to see what water quality tests have been conducted and certainly don't expect to be shown the test data.

Still, if the water is out of specs, I believe PUB will then bring pressure down on your town council or BMC to better on the ball on its maintenance programme. Either way, you are safe. Do you still need a water filter then?

Remember the rusty silt that makes your water look "dirty"? Yeah, it is supposed to be safe. Meaning no one, including your town council, will be doing anything about it. Iron (or rust) can be bothersome because it can impart a metallic (or bloody taste at higher concentration) taste. Another problem of iron/rust is it can stain clothes, walls, floors. What colour of stain? Think of rust - orange, red, brown and any colour in between. 


Source: https://sprinklerwarehouse.files.wordpress.com/2012/08/rusty-pipe-small.jpg
Notice the orangey stuff inside the pipe - that is the tell tale sign of iron. Yup, it is a form of rust. They usually arise from cast iron or galvanised pipes.

If it bothers you (it BOTHERS me), by all means, get a filter to remove it. Nothing fanciful, a cloth filter can do the job. Or if you want something more reliable and can afford the space, get a 10-inch sediment filter rated for 10 microns or less. The rating tells you the maximum size of a particle that can go through i.e. anything more than 10 microns will not pass through the filter.

Figure: A 10-inch 5-micron pleated filter used for experimentation

So far, I am only talking about iron in water. Piping can impart other less desirable and far less benign pollutants into your drinking water. This is usually true in older piping before people became enlightened about the dangers of various materials in drinking water.

1. Case in point - lead. Commonly used in old piping networks in solder at the joints. Hong Kong has an interesting case - "Water pipes of thousands of flats in Hong Kong will have to be replaced after initial tests revealed excessive levels of lead in the water of a two-year-old public housing estate in Kowloon." Yup, the year was 2015 and the housing was only 2 years old. The blame was placed on the plumbers (and later the contractors) who used substandard materials containing lead solder (banned in HK) from China.
   
   As a follow-up to the HK story, attention then turned to Singapore as one of the contractors (China State Construction) was also involved in some projects here. Rising to the occasion, PUB categorically replied, "Lead or lead alloy, and water fittings made of lead or lead alloy, including soldering joints with lead content are not allowed for use in potable water supply systems in Singapore"
   
   Results of lead poisoning are well known. As a neurotoxin, it causes mental retardation. Children are especially vulnerable, leading to learning difficulties and delays in development. Unfortunately, lead can come from the food we eat (e.g. adulterated medicines) and the air we breathe (e.g. lead dust from leaded paint).
2. Asbestos. This was formerly used in cement piping for reinforcement. Over time, as the cement pipe undergoes wear and tear, the asbestos fibres can end up in the water. Though inhalation of asbestos is the most common route of entry, evidence suggests that cancers in the esophagus, larynx, oral cavity, stomach, colon and kidney may be caused by ingesting asbestos.
   
   I can't really find any data on the usage of such piping in Singapore. If anyone has any information, please let me know.
3. Copper. Possibly from copper pipes. The copper corrodes over time into water. Bluish green stains are signs of copper in water. Less of a health concern unless the concentration is high. You can sometimes see the same coloration on the exterior of copper pipes because the copper has reacted with substances in air.

Rainwater Harvesting Advice

There have been several queries about setting up a rainwater harvesting (RWH) system in households. But I believe the demand is still not great enough for vendors to emerge to actually design and install such systems in Singapore. See my thoughts on this matter in the reply to a typical query below.

I chanced across your article on rainwater harvesting at (http://waterqualityinsingapore.blogspot.sg/2013/08/more-power-to-rainwater-harvesting-in.html) while doing some preliminary research on the feasibility of a simple rainwater harvesting system for the semi-detached house I'm living in. You said in the article that the installation of a rainwater harvesting system has been legalised since 2004, subject to some commonsensical regulations. 

Currently, my parents use multiple pails placed under an awning to collect the run-off from the house. There are several problems to this that I am sure you are aware of:

1) The pails collect the initial run-off which carries all the dust, dirt, bird-shit, lizard-shit, and goodness knows what else;

2) The pails are left open, which leaves it prone to mosquito breeding, which in fact has happened multiple times;

3) The pails are extremely heavy once it is full with water and it is difficult to carry it around the house. 

I have been trying to convince my parents on the wisdom of installing a proper system with a filtration, tank, pump and some pipes that can distribute the rainwater around the perimeter of the house for easy and convenient access. Or, if the pipes are too much of hassle, then a simple tap at the bottom of the tank would do. 

 

However, the main problem I've faced is in finding a product, or a person, or anyone who has actually done this (besides having to email Dr Tan Cheng Bock himself) to consult. Thus I beg your kind recommendations on how I should proceed from here. 

I have found one: http://www.ksb.com/ksb-sg/Products_and_Services/building_services/water_supply/Hya-Rain_Eco/401028/rainwater_harvesting_system_Hya-Rain_Eco_art.html but that's about it.

Sincerely,

M

Hi M,

Thanks for sharing your personal story of rainwater harvesting (RWH).

RWH is not an easy task for the homeowner in Singapore. Few people are doing it so there is little demand for vendors of RWH equipment in Singapore. Even those homeowners who are into RWH mostly use pails to collect the rainwater like you do.

As for the link you provided, I don’t really know what to make out of it. It claims “plug-and-play” but when it comes to piping, connections/interfaces, types of usage for your rainwater, there are simply so many variations and combinations that “plug-and-play” sounds too good to be possible. I didn’t go exploring further but the page did not show any specifications e.g. pumping pressure, tank volume. Furthermore, there is no mention of a first flush device which I absolutely believe is essential. It basically removes the initial volume of rainwater which is the dirtiest portion of harvested rainwater. Such a device will greatly enhance the cleanliness of your rainwater. There is also no mention of any filtration of the rainwater. As I have mentioned before in my blog, rainwater is one of the cleanest forms ofwater but again depending on  your purpose (e.g. drinking), you may need further filtration.

My suggestion is to read up a bit on RWH and come up with a simple design for your house. It is not that difficult if your system is simple. You probably already have gutters on your roof. Join them to a down pipe with an inline first flush diverter and then connect to a plastic tank with a spigot. Viola! You have your very own RWH system. (As mentioned above, if you want your rainwater for drinking, you may want further treatment.) Then bring this design to an engineering vendor to source for your parts, smooth out the piping and assemble everything for you. Job done!

The vendor I used for my RWH project was Joo Lee Engineering. (Addendum: Just like the rest of 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.)

More recognition to grey water recycling!

Grey water (1, 2, 3) recycling has always been a less glamorous cousin to rainwater harvesting. After all, rainwater is clean water for drinking, bathing, cooking... all important processes for our health and well-being, while grey water is wastewater best kept out of sight and mind... as long as someone else is taking care of its disposal.

News update: Water is water is water (no typo here) by whatever name. The only difference lies in the "impurities" in the water, hence giving rise to black water (toilet bowl), grey water (sink, laundry, bath), yellow water (urine only), dark grey water (kitchen sink, diapers laundry). All water is intricately connected in the water cycle - both natural and human. In other words, rainwater or any other "clean" water can come from grey water. Therefore, it pays to conserve (read recycle) and handle your grey water properly.

It is therefore great news when I see that PUB has added a section on the guidelines of grey water recycling in Singapore.

1. Alternate sources of water
http://www.pub.gov.sg/conserve/CommercialOperatorsAndOther/Pages/AlternateSourceofWater.aspx
On this page, rainwater and grey water are officially recognised as alternative sources of water, not just at the national level or at the residential/individual level. I have written about rainwater harvesting in an earlier post.

2. The document itself
http://www.pub.gov.sg/conserve/CommercialOperatorsAndOther/Documents/greywaterRequirements.pdf

Some highlights

1. It goes without saying - no potable use. But irrigation and general washing are also forbidden. Why then do you recycle grey water???
   
   Well.... it can only be used for toilet flushing and as cooling tower make-up water.
   
   Personally, depending on your treatment process, grey water can even be made potable. Even with simple treatment, its water quality can be made adequate for general washing and irrigation.
2. As for rainwater harvesting, grey water recycling must follow PUB's standards for fittings and code of practice for water services, as well as NEA's standards for prevention of mosquito breeding.
3. Raw grey water should not be stored for more than 24 hours. This IS reasonable as any time longer will lead to anaerobic conditions and foul odours.
4. Treated grey water should not be retained for more than 72 hours. This DEPENDS on the type of treatment. If the final water quality is that of drinking water, I am sure the duration can be stretched.
5. Incidentally, there is no mention of WHAT type of treatment process you should use... Instead, whatever treatment must produce a water conforming to the water quality guidelines (listing the various water quality parameter and their limits) given in this document. This is immensely useful as previously, there were no such guidelines.
6. And also very useful is the schedule for water sampling and monitoring e.g. testing for E. coli and coliform should be done monthly.

 Figure: PUB guidelines for treated grey water quality

Figure: PUB sampling regime for treated grey water

Source of the above 2 figures: PUB document (http://www.pub.gov.sg/conserve/CommercialOperatorsAndOther/Documents/greywaterRequirements.pdf)

In conclusion, I believe we are on the right track on publishing such standards for grey water in terms of its water quality and testing schedule. I hope more developers and individuals will take up the challenge to implement grey water recycling on a residential or building scale.

Natually, there is much more to be done. E.g. I am impressed when habitats use plants not only to clean up grey water but also to provide edibles for their inhabitants. Bananas can be clearly seen in my previous posts (1, 2) illustrating this concept in an Earthship.


Figure: Bananas, anyone? (Source: http://blog.insureandgo.com/food-and-drink/2013/03/8-amazing-facts-you-might-not-know-about-bananas/)

More power to rainwater harvesting in Singapore!

Hi folks,

It has been a long while (Mar 2004 till now to be exact) since Dr Tan Cheng Bock (Singapore presidential candidate in 2011) advocated water conservation by implementing a rainwater collection tank to water his garden despite the illegal nature of such an act before that time. See Straits Times article below (dated 16 Mar 2004).

Source: Straits Times 16 Mar 2004



Before 2004, collection of rainwater was forbidden except for the use of pails in residences. Building a rainwater tank was strictly a no-no. Rationale: rainwater was a property of PUB acting in the best interests of the nation in water conservation and rainwater collection via the canals and drains that ultimately flow into reservoirs (technically, only two-thirds of the land area here is available for rainwater catchment so not all rainwater is channelled into reservoirs). Yes, you are expected to let the government handle YOUR water needs. What a mentality...

Since then, even though not widely known, rainwater harvesting has been legalised for households as long your rainwater storage tank is no bigger than 5x2x2m (or you will have to pay a levy for wastewater treatment) and your rainwater is for non-potable uses. Institutions and companies will have to apply for a permit if they want to implement rainwater harvesting. Still, many got their permits e.g. Changi Airport (1, 2), Nanyang Polytechnic, Poh Ern Shih Temple.

But now, it is official!

Details are now more clearly spelled in PUB's website:

1. Alternate sources of water

http://www.pub.gov.sg/conserve/CommercialOperatorsAndOther/Pages/AlternateSourceofWater.aspx

This page also includes grey water recycling (I will cover this in a separate post) which is now officially recognised too! How exciting!

Some highlights:

• Owner/developer/QP/PE can submit an application to PUB for rainwater harvesting.
• Please note that rainwater is only (and still) for non-potable use.

2. GUIDANCE NOTE FOR THE APPLICATION OF RAINWATER COLLECTION SYSTEMS
http://www.pub.gov.sg/conserve/CommercialOperatorsAndOther/Documents/GuidanceNotes.pdf
More details can be found in this document.

Some highlights:

• Not surprisingly, rainwater harvesting equipment has to comply with the Code of practice for water services and the fittings must follow the standards under PUB.
• What are your non-potable options in the use of rainwater?
• general washing
• toilet flushing
• irrigation
• Sorry, no bathing and washing of hands... (and I though that rainwater is supposed to be good for your hair)
• Excess rainwater should be allowed to overflow into drains which of course goes back to becoming the property of PUB.
• Don't forget the other governmental big brother, NEA. Your rainwater system also has to comply with NEA's guidelines, especially concerning mosquito breeding.
• GUIDELINES ON MOSQUITO PREVENTION IN DOMESTIC RAINWATER COLLECTION SYSTEM FOR NON-POTABLE USES http://www.nea.gov.sg/cms/ehd/Guidelines_on_RainWaterCollectionSystem.pdf
• Guess what... gutters are now allowed (though "discouraged") for rainwater harvesting provided they follow the guidelines given here.
• The same rainwater is not supposed to remain for more than 7 days in the storage tank (translated as residence time to the engineer reading this).

3. Drainage handbook
http://www.pub.gov.sg/abcwaters/ABCWatersProfessional/Documents/managingUrbanRunoff.pdf
A big document - 82 pages. More for further info and background.


My take
Well and good. People should have a role in conserving and utilising this precious resource. No doubt, centralised rainwater harvesting by PUB is indeed useful. However, the people need to be allowed more freedom for initiative to take care of themselves and the environment.

Personally speaking, rainwater is really clean water. The possible contaminants will be dust and dissolved gases and whatever that adds into the water by the collection system e.g. bird droppings, dead insects. After some minimal treatment, rainwater is certainly potable. As mentioned in a previous post, I strongly suggest rainwater as compared to other sources for consumption rural/developing communities overseas.

Figure: Source: Straits Times c2003. Rubbish choked water in Muara Baru, north Jakarta. I don't know about you but I prefer to get my water from the rain rather than from surface water like this. 

Green project part 3: Integrated rainwater harvesting and grey water recycling systems

You may click on these links for part 1 and 2 of this green project.

After months of planning, sourcing, talking to vendors etc., the prototype for the rainwater harvesting (RWH) and grey water recycling (GWR) systems is up. This prototype combines both systems into a single framework (pun intended) and is intended for testing the components and process flow as a coherent whole. Though the final design in the "actual" project will appear very different, this prototype and the actual system basically share the same elements and process flow.

Our SP Library has kindly allowed the prototype to be placed in their garden for testing. Bravo to them!

Figure 1: Figure shows the mini grey water recycling system incorporating  plants as the "filters" in 3 separate cells. In the background, you can see the book shelves of the library. If this prototype proves successful, it may be placed as it is for the long term as an educational tool for our students. Posters will then be fixed strategically to explain the capabilities of the system and how it works.

Figure 2: To polish up the grey water and the rainwater, off-the-shelf filters are installed. Depending on the quality of your input and the desired quality of your output (what do you want to use your treated water for?), these filters may not be necessary.

My current green project part 2: rainwater harvesting system

Here is the 2nd part of my involvement in a major green project in the form of a mindmap presented to the participants of the project. The green technology here harvests and treats rainwater to a suitable quality for further use. Similar to the previous post, it touches on the design considerations for builidng a rainwater harvesting. (Click on the figure on look at the whole map.)
Fore more on rainwater harvesting information, refer to my previous posts here.

Phytoremediation of Wastewater

Hi Chen Ko,


Hope all is well with you. While researching on phytoremediation for wastewater, I chanced upon your blog.
http://waterqualityinsingapore.blogspot.com/2010/03/before-you-write-off-plant-as-weed-read.html

Your blog has enhanced my understanding of phytoremediation and its potential in SEA. In the blog, you mentioned Earthship Biotecture. Do you happen to know the company/inventor behind this concept?

Thanks.
Best Regards
I


Hi I,

Glad to hear that you find my post useful. From what I know, Earthship Biotecture was founded by Michael Reynolds. The idea of an Earthship is a self-contained living environment that maximises the recycling of water - closing the loop as they call it, and minimises the wastage of energy. Food is actually a "by-product" of the recycling of water. Though it does not mean 100% self-sustaining as in a spaceship, the concept is nevertheless useful as a model for future housing.

If you are seriously interested in Earthship, you can actually sign up at the website as a volunteer to help out in the construction of their current projects. Unfortunately, there are no projects in our region as they are mostly located in the U.S.

Or if you prefer to find out more before diving head-first into the physical work, check out the 2 books by Michael Reynolds.

1. Earthship
2. Water from the sky

Here is a review of book #2 that I have written for my campus library in 2007.


Do you want to harvest rainwater and recycle your wastewater so that you will never have to depend on public utilities? Perhaps you simply want to reduce your rising water bills. Or perhaps you are an environmentalist at heart and feel strongly about conserving such a vital resource like water. If you have any of the above goals, this book excels in illustrating the processes of rainwater collection and recycling of both grey and black water. Detailed designs are available for the reader to immerse into the bolts and nuts from choosing the right materials to building a functional system which includes water treatment for rainwater, grey water and black water. Numerous photos and illustrations enable the reader to visualise each stage of the construction. This is however not a science book since the scientific reasons behind most designs are not well explained. The reader is advised to find out more about the science from other sources. One major shortcoming is the lack of costing details, impeding the reader from gauging how economical such a system is. Even though the author claims that the recycled water is drinkable after treatment, there is no mention of any physical, chemical or microbiological test being done. The relevant tests would have strongly validated his claims. Despite the above inadequacies, the book presents plenty of useful hands-on information that many “scientific” books lack. It should be read by anyone interested in rainwater collection and wastewater recycling.

How to reduce flooding in Singapore? Harvest more rainwater!

Harvesting of rainwater may sound foreign to most of us even though this term is commonly used in other countries. It simply means collection and storage of rainwater. It may be on an individual, residential, community or even national basis.

Actually, Singapore has been harvesting rainwater for a long time on a national basis. From PUB's webpage, two-thirds of the land area here is available for rainwater catchment (Yes, right, "catchment" is more commonly used here).

(Figure: www.pub.gov.sg/water/Pages/LocalCatchment.aspx)

Is so much of our area covered by reservoirs? NO! It means that land (residential, industrial, recreational, waste etc.) is used to funnel all that rainwater into reservoirs. For example, rainwater falls on rooftops, flows into drains which lead into canals, ultimately joining up with a reservoir. Because of the flash floods in June, everyone now knows that Orchard Road is part of the catchment area for the Marina Reservoir. Talk about practical environmental education.

Indeed a very clever system to alleviate the shortage of water in this densely populated island. However, it suffers from a few drawbacks.

One, in times of heavy rainfall, no way will the reservoirs be able to hold so much water. The natural thing to do is to drain the excess into the sea. (E.g. the Marina Barrage is well touted to be able to do this in the event of heavy rains.) This of course means a waste of fresh water. AND IF the excess CANNOT be drained (e.g. blockage of some water way), flooding will result. In the (good?) old days when Singapore is still a tropical jungle, most rainwater will be soaked up by the vegetation and soil. But with the increase of built-up area, we no longer have such a luxury. Most rainwater will flow over the ground surface straight into drains and canals or perhaps accumulate in some low lying area as a flood.

Another challenge of open reservoirs like ours is the loss of water through evaporation. In the dry months, the water level in the reservoirs drops not only because of the lack of rainfall but also through the above mentioned loss.

This article predicts that the rainwater harvesting (RWH) markets in Europe and India are set to experience high growth rates in the coming years due to a rising fresh water shortage. More RWH systems will be installed at the residential, commercial and industrial levels.

Guess what? This is nothing new in Singapore! Changi Airport has such a system. Nanyang Polytechnic has one too. The airport is reported to satisfy one-third of its water demands in this manner, saving $390 000 per year. Such water is normally collected on the roof-top and undergoes minimal treatment for non-portable use e.g. toilet flushing, firefighting drills, watering of plants.

Imagine... if we have more of such systems, not only will our reservoirs be less stressed in times of heavy rain, there will also be less loss of precious fresh water through evaporation.

If your interest has been piqued, how do you set up a RWH system. SIF Technologies is selling a "chemical free RWH system". Chemicals are sometimes added in conventional water storage to discourage microbial growth. (Chlorine in PUB water does this job.) In the case of SIF, they are using a proprietary non-chemical means to do the same thing.

But RWH can be simple and cheap. Consider this 3rd world method of RWH. However, remember to always discard the first 10min of so of rainwater as it may contain pollutants from the air or your roof-top.

Figure: using a tin roof to collect rainwater (Water for Life, Hesperian Foundation)

Figure: My own version of a RWH system for use in a high-rise flat from a project several years back. (Naturally, we can't have every household in a HDB block harvesting rainwater. I suspect only the top floors will get any significant amount. The other concern is not to have a high-rise RWH system becoming killer litter.)

Oh, before you rush out to install a RWH system, here is an extract from Singapore Law.

SEWERAGE AND DRAINAGE ACT

PART V PROTECTION OF WATER RESOURCES
Prohibition on extraction of water
No person shall, without the approval of the Board (PUB), construct any works for taking or intercepting water from any place or sea, within the territorial limits of Singapore.

However, I believe the law has been relaxed for residential installation provided the storage tank is less than a size of 5x2x2m. Anyting bigger will require a water-borne fee to be paid. But if you are planning a system for your company or school, you still have to go through the bureaucracy for permission. One last point, check out the guidelines for collection of rainwater at NEA.

(Update: Rainwater Harvesting Seen as Solution for Drought and Flood Control: In Kenyan cities like Nairobi, rainwater harvesting is seen as a solution to multiple problems.)