When was the last time you drank water straight from the tap at your house to slake thirst on a hot summer day, without hesitation. Chances are you would have at least boiled or filtered the water. The public water supply in India is so unreliable that the urban middle class, with its increased spending power, prefers shelling out an extra buck on one of the numerous water purifiers available in the market, rather than risk health. In a decade or two, more than half of India will live in urban areas. Will they have better options? ...
There is no denying a rising demand for purifiers. But what are these technologies and how effective are they? What are the standards they conform to? suresh babu s v studies the purifier market and technologies for answers.
Pure myth
When was the last time you drank water straight from the tap at your house to slake thirst on a hot summer day, without hesitation. Chances are you would have at least boiled or filtered the water. The public water supply in India is so unreliable that the urban middle class, with its increased spending power, prefers shelling out an extra buck on one of the numerous water purifiers available in the market, rather than risk health. In a decade or two, more than half of India will live in urban areas. Will they have better options? Unlikely. The country does not have the capacity to treat more than 80 per cent of the waste generated in urban houses, leading to pollution of surface and ground water. The quality of groundwater is also deteriorated because of overexploitation. Bad water, of course, is bad health. Says Manoj K Ved, a doctor practising in Mumbai's Gorai area "On an average, 25 per cent of the cases I attend to are related to water-borne diseases."
Water-purifier manufacturers and dealers make bad water a selling point. There is a host of brands and varieties to choose from--from Aquaguard and Pureit to Zero B. But how many of us can make an informed choice? "People do not really know the correct criteria for choosing the right purifier," says Ashim Sanyal, chief operating officer, voice, a Delhi-based consumer rights ngo. Never mind, the salesman is at your doorstep, hoping to convince you that his purifier is the best in the market. Water-purifier manufacturers are even tying up with builders to install household-treatment systems or centralized plants for upcoming colonies. "There is a huge demand from builders to install reverse osmosis ( ro) systems in residential areas. The cost is passed down to the buyers," says C K Sandeep, associate vice-president, Ion Exchange India. "We have installed over 3,000 ro systems in our projects in ncr, Lucknow and other places," says Ajay Kumar, director, Amarpali Group. Some builders have gone a step ahead and installed large ro plants for the entire residential colony, which manages its own water supply. Alok Vihar, a group housing society in Noida, for one uses a central, three-step purifying system a carbon filter to remove taste and odour, a secondary filter for removing impurities up to the size of 0.2 micron and finally an ro membrane. The treated water is filled in 20-litre cans and delivered at door steps. "Groundwater here is brackish. Since we did not have a municipal water supply, there was no option but to go for an ro plant," says Anil Bhalla, one of the residents.
There is no denying a rising demand for purifiers. But what are these technologies and how effective are they? What are the standards they conform to? suresh babu s v studies the purifier market and technologies for answers.
Fortune cookie
Talk about his company's fortunes is likely to elicit a beaming smile from Mahesh Gupta. Kent RO systems' managing director says that his company's profits grew 40 times between 2002-2003 and 2007-2008 from Rs 2.5 crore to Rs 100 crore. Other water purifier manufacturers also say that business is good. Are they making tall claims? Or are they making hay while the sun shines?
Actually a bit of both. There is little doubt that the water purifier market is growing. But accurate market size figures are hard to come by. A 2005 study by us- based consultancy firm Frost and Sullivan notes that one in every 40 Indian households uses water purifiers. R S Rajan, vice president consumer marketing of the Mumbai-based Ion Exchange, says that water purifier penetration in the country ranges from 25 per cent households in Delhi to 0.42 per cent in cities in Bihar (see graph For clean water. There is also no unanimity on the value of the market.Ion Exchange puts it at Rs 800 crore, Frost and Sullivan says it is worth Rs 1,400 crore and Eureka Forbes pegs the figure at a little more modest Rs 1,000 crore.
Market share figures are similarly obfuscating there is no government data, and claims of different companies simply don't add up. For example, Kent's claim of a 40 per cent urban market share would not hold much ground if Eureka Forbes' contention of a 70 per cent market share is found to be accurate.
Rajan puts the issue in perspective. "Market research is tailormade," he says.
Frost and Sullivan does say that "Eureka Forbes, Kent RO, Usha Brita and Ion Exchange are the biggest operators in the Indian water purifier market." But the us- based consultancy also points to another significant player the unorganized sector with a 45 cent share in the market.
Spoilt for choice?
S Mushtaq Khan of Frost and Sullivan says, "Ultraviolet (uv)- based systems dominated the market in 1990s. Reverse Osmosis (ro) systems are gaining acceptance though they are costlier," he says. Pritee Shah, editor of the consumer magazine, Insight concurs. "Marketing stunts have created the impression that water can only be purified by the reverse osmosis (ro) system," she says (also see box A film star speaks).
| For clean water |
| Penetration of household water purifiers |
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| Source R S Rajan, vice president, consumer marketing, Ion Exchange India Limited, Mumbai, personal communications, February 20, 2008 |
Most water purifiers today combine two or more treatment processes. These include
ro, uv, filteration and disinfection technologies. Industry insiders point out that Eureka Forbes, conventionally known for
uv- based systems, has integrated
ro and carbon filtration into its products. Frost and Sullivan says that 51 per cent of the purifiers in India are
uv- based while 42 per cent are
ro systems and the rest candle and resin filters. This is going against the global grain where
ro- based systems hold just 11 per cent of market share.
But are
ro systems suited for Indian conditions? C K Sandeep, associate vice president Ion Exchange says, "
ro is not needed at places where total dissolved solids are less than 500 mg/l. In such conditions
ro systems are very likely to rob the water of essential minerals ." Other critics talk of the huge water wastage 60-75 per cent water goes waste with
ro systems.
Such inefficiences have not been addressed by recent innovations. Most of them have been cosmetic. Innovations on operation and maintenance come at a cost.
ro systems require cleaning every three-six months.
Membranes have to be replaced every one-and-a-half to two years. Normally, first year servicing is free while subsequent services have to be paid for charges range from Rs 1,200 to Rs 3,600 based on the product.
Costly. But how effective?
A water purifier has to deal with physical, chemical and biological adulterants including dissolved solids, heavy metals and pesticides. Besides, all contaminants have different characteristics like molecular weight and size, water solubility, volatility and ability to react with oxygen. So, water treatment is a multi-pronged process, and the contaminant challenge has a big say in selecting appropriate technology.
Treatment processes either remove contaminants or destroy them. Removal technologies include ion exchange, adsorption and filteration (see flow diagram Water treatment). Then there are technologies that decompose chemicals and pesticides by oxidation or hydrolysis. Chlorination, for example, is also known to oxidize and remove many pollutants. Disinfection is a similar technology.
Let us now see how most common filters work
Activated carbon filter
These filters follow a two-pronged approach.Firstly, some contaminants are blocked by pores--filters with small pores are more effective.
Secondly, these purifiers have carbon filters which draw molecules from dissolved contaminants--this process is called adsorption. Characteristics of the carbon material--particle and pore size, surface area, surface chemistry, density and hardness--influence the process's efficiency.
In many household filters, carbon's adsorbing powers are enhanced by adding a slightly-positive electrical charge. As water passes over the positively charged carbon, the negative ions of the contaminants are drawn to the surface of the carbon granules and are removed.
Activated carbon filters typically use granular carbon or blocks of powdered carbon. The latter remove more contaminants, including volatile organic chemicals (vocs), pesticides and herbicides, chlorine, and other chemicals found in tap water. It also removes unpleasant taste and odour. However, some heavy materials and bacteria can slip through the filter cartridge if the carbon is not densely-compacted. Carbon filters need recharging.
Ion-exchange filters
Ion-exchange is mostly used to remove hardness in water caused by carbonates and bicarbonates of calcium and magnesium. These filters have a resin bed, which draws out calcium ions and magnesium ions in water and replaces them with sodium ions.
| Water purifiers must address the contaminant challenge |
Ion-exchange filters can remove iron, lead, copper, barium, radium and nitrates. Some such filters can also remove arsenic and selenium. Suraksha, one of India's earliest tap filters, used the ion-exchange process. Now, most filter manufacturers prefer integrating ion exchange into a system that has several water purifying technologies.
Reverse osmosis filter
ro uses pressure to force water through a membrane that retains the contaminants on one side and allows the pure water to pass to the other side (see diagram
How reverse osmosis refines water at a micro level)
ro purification units involve two processes. The unit consists of two filters a carbon or sediment filter, also called pre-filter and a semi permeable membrane. The pre-filter removes large particles from the water before it passes through the semi permeable membrane.
The membrane allows water to pass through, but traps pollutants and bacteria in its porous surface. Some
ro systems also have a
uv disinfectant which rids water of microbiological contaminants. The flow rates of these household filters vary from 8 to 72 litres per hour
Today, reverse osmosis has become very popular and its proponents claim that
ro can remove virtually every contaminant. But that's a myth.
| RO filters waste 60-75 per cent water |
| Complicated mechanism |
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| A lot of systems combine a variety of filters |
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| Source www.espwaterproducts.com as viewed on February 28, 2008 |
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who says that
ro systems cannot completely remove some pesticides like lindane, solvents and other
vocs.
The cost of household
ro filters range from Rs 9,000-Rs 46,000 and they are heavy on maintenance.The pre filters and the
ro membranes must be changed according to the manufacturer's recommendation. The storage tank must be cleaned periodically. Damaged membranes are not easily detected, so it is hard to tell if the system is functioning normally and safely (also see box
Think before you use ro).
There are other negatives. As the water free of contaminants passes through the membrane, highly concentrated wastewater is discharged. 60-75 per cent of the water is rejected in an
ro system. The amount of water rejected by the system depends on the quality of raw water, particularly its dissolved solid content
Ultra Violet light disinfection systems
In such filters, water is passed through a clear chamber where it is exposed to
uv light, which destroys bacteria and viruses.
uv lamps found in filters in the Indian market last 5,000 to 10,000 hours of operation.
The system's efficacy depends on the resistance of an organism. If the energy dose is not high enough, an organism's genetic material might only be damaged--and not disrupted. This means the organism would remain and can regenerate in suitable conditions.
uv cannot be a stand alone treatment process because water has multiple contaminants.
A water purification system must have a high quality carbon filter or a reverse osmosis system if it has to contend with heavy metals and chemicals.
uv filters are employed as the final purifier in some systems.
Some advantages of
uv filters are
It does not introduce any toxic or significant nontoxic byproducts
Does not alter smell or taste of treated water. In fact, it actually improves the taste of water taste by destroying organic contaminants
Does not affect minerals in water
Cleanses in seconds (chemical disinfection takes several minutes).
The system's disadvantages are
It is not suitable for turbid water with high levels of suspended solid or soluble organic matter. This can react with
uv radiation, reducing the quality of disinfection
uv light is also not effective against soluble salts, pesticides, heavy metals, manyorganic chemicals and chlorine.
The best technology
Marketing gimmicks have created the impression that
ro is the most effective technology to remove pesticides and other toxins from water. Kent RO systems, for example, has come out with a purifier which claims to adjust dissolved solid levels and minerals in water by a mere turn of a knob.
However, the third edition of
who's guidelines for drinking water quality point out that more conventional technologies like activated carbon and ozonation are most suitable for removing pesticides and other organic chemicals.
The guidelines show that activated carbon is more effective for removing most pesticides (see table C
heap technologies do well).
who also has a system to rank water purifiers according to their complexity and economics. Activated carbon and ion exchange are ranked the highest, while membrane treatment is deemed the most complex and costliest.
| Cheap technologies do well |
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| In removing pesticides |
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Note + stands for limited removal of the contaminant; + + for 50 per cent removal and triple plus for 80 per cent removal
Source Anon 2003, Guidelines for Drinking Water Quality, 3rd Edition, World Health Organisation, Geneva, October |
|
Integrating technologies
Integration of different technologies is more efficient in dealing with a complex pollutant matrix. And in fact, lot of modern day filters integrate different processes.
A typical system is shown in the diagram it is basically a reverse osmosis system, which employs pre-filter mechanism to remove odour and taste impurities. At this stage, some chemicals--up to about 0.2 micron--are also removed.
The water is then passed through
ro membranes. At this stage concentrated waste is discharged and fresh water is passed through another filter to remove any contaminant--chemical or microbial--that would have escaped the
ro membrane's pores.
Some systems employ
uv light at the end of the treatment chain to get rid of bacterial contaminants.
Purifying the purifier
A consumer looking for a water purifier is most likely to be confronted with a fusillade of quality claims. K J Nath, president, Institution of Public Health Engineers in Kolkata is not sure about their veracity. "A lot of the tall claims by private players cannot be substantiated scientifically," he says.
Down To Earth asked a few manufacturers about the standards they adhere to. Most produced lab reports and rolled of terms like certified by nsf international usa, endorsed by the Indian Medical Association (ima), tested by university of Minnesota, bis certified, member of the Water Quality Association, usa.
What about the testing criteria at these national and international laboratories? We wondered. Our investigations revealed that these varied and were sometimes even irrational.
A consumer needs to know the contaminant challenge, the quality and source of water, for which the purifier was certified. But consider, for example, a 2006 report by Spectro Labs Delhi. It stated that a model manufactured by Kent cleansed to packaged drinking water standards IS 14543 2004. Heavy metals were within limits stipulated by this standard, the report noted. But most heavy metals were within prescribed limits in the untreated water itself. So, the purifier had actually done precious little. It had only removed microbial contaminants, tds and salts. IS 14543 2004 standards also stipulate that there should not be any pesticide in water. But the Spectra Labs report made no mention of pesticide levels in the treated water.
We then decided to check on certificates issued by the Indian Medical Association. Were they also indifferent to the contaminant challenge? A certificate given by the association to Eureka Forbes in 2004 came as a revelation. It showed that the association actually does not test water purifiers. The certificate said, "Endorsements....(are) issued after examining all quality certificates obtained... from various labs and being satisfied about the same. ima endorses and approves the range of products mentioned above as being in conformity with the international standards for providing safe drinking water."
| Standards don't account for changes in pollution profile |
There are hundreds of other companies who claim substantial contaminant removal without any backing or certification. It is high time regulations were laid down to help the consumer make an informed decision.
Vacillating bureau
The Bureau of Indian Standards (
bis) does have standards for some water purifiers like
uv filters and candle filters. But these standards were developed between 1979 and 1999, when it was believed that water purifiers were meant to remove only bacteriological contaminants (
see table Outdated and inadequate). Besides, these standards only apply to water that is free of chemicals and suspended matter. But as Nath points out, "Besides removing faecal coliform, water purifiers must also get rid of viral and parasitic pathogens as well as toxic chemicals like arsenic, fluoride and pesticides."
More importantly, the most sought after
ro systems are outside the pale of standards.
Within the
bis there is some awareness that the standards have not kept pace with changes in technology and pollution profile. The issue was, in fact, raised at the bureau's sectional committee meet on drinking water standards on February 5. But the priority seemed to be on revising drinking water standards.
Prakash S Kelkar, chairman of the committee who also heads the Nagpur-based National Environmental Engineering and Research Institute's geo-environmental monitoring division said, "Drinking water standards (IS 105001991) in the country are much lenient compared to that set by the
who or the
us Environmental Protection Agency. Once we zero in on drinking water standards, we can move on to discussing norms for water purifiers." He did, however, suggest that "the first step towards setting standards is to have an independent and comprehensive assessment of the performance and claims of various filters."
Water purifier standards are also snagged because the
bis can't seem to decide which of its divisions should take up the matter. Standards for
uv filters were developed by the bureau's hospital equipment sectional committee, while those for candle filter were developed by ceramic ware sectional committe e. But there is no agreement on who should frame comprehensive standards in view of the changing market and the changing pollution profile (see box bis
standard on drinking water).
What shall be the standards?
bis can draw lessons from international standards. A good example is the
us standards drawn up by the
ngo, NSF International. Water purifiers are certified for
nsf standards by another not-for-profit group, the Water Quality Association. There are seven standards that cover a range of technologies and their performance claims. There are two sets of standards for carbon and ceramic systems that address health and aesthetic parameters.
| Outdated and inadequate |
| BIS standards on water purifiers need a revision |
| Standard |
Salient features |
| IS 147241999 Water purifiers with ultra violet disinfection |
Applicable to systems which rid water of water-borne pathogenic bacteria and suspended matter. Cannot filter dissolved solids or chemicals |
| IS 74021986 Specification for filters for drinking water purposes |
Covers ceramic candle filters that remove suspended matter and bacteria. Cannot filter dissolved solids or chemicals. Materials used to make the filter should not mar drinking water safety. Filters must have information on the amount of water it can purify before it has to be cleaned |
| IS 93101979 Specification for water purifier (electrically heated) |
Covers potable water purifier used for consumption in dispensaries, hospitals and in medicine preparation. Labels should contain instruction to boil water for minimum 30 minutes |
|
The standards address the following issues
Product material safety The standards ensure that the product does not add any contaminant to water
Structural integrity The purifiers can work under high pressure
Literature and labelling They stipulate that there should comprehensive guides to aid installation, operation and maintenance. They also require that manufacturers corroborate performance claims with data sheets
Contaminant reduction claims A water purifier need not clean water of all contaminants. But manufacturers must specify the contaminants their products can check. There are different standards for different contaminant challenges. For example, standard number 53 applies to carbon and ceramic filters. Water purifiers can claim adherence to this standard if they cleanse 95 per cent of 300 parts per billion coliform. Pre-and post filters in an
ro system must also be certified seperately.
Crying out for action
Industry sources exude confidence about the water purifier segment. Manufacturers peg their hopes on the increasing purchasing power of the middle class in cities, small towns and the suburbs.
The water filter market thrives on a vicious circle. With municipalities failing to provide safe potable water, many turn to groundwater; overextraction affects water quality and water purifiers become the last-resort choice.
Most people who resort to water purifiers do not even have information on water quality. It also doesn't help that there are no laboratories where people can test water.
At the same time, bis and the ministry of consumer affairs have to fix standards for the water purifier industry in ways suited to Indian conditions. The product should be verified for its contaminant removal claims over its life span and also be tested for material safety.Labeling is another important requirement manufacturers should be accurate in describing which contaminants their product can remove and to what extent. Operational and maintenance details must also be specified. Standards should deal with the applicability or the necessity of technologies in different conditions.
Norms to cut down water wastage must be laid down, especially for ro systems.
But purifiers cannot solve the problem of bad water quality. At best, they can offer partial solutions. Water purifiers are for the rich. It is no surprise that Delhi and Mumbai which have a huge population of rich and middle classes are the biggest markets for water purifiers.
| We can't first pollute water and then clean it up |
Our municipalities must also get their act together. The current system only encourages wastage 30-60 per cent of treated water does not reach the consumers. Also it is estimated that urban India will invest Rs 69,000 crore in the next five years on water supply projects. The eleventh Five Year Plan also projects that urban water supply systems would on average spend Rs 8,300 crore annually on operation and maintenance--almost 1.4 times higher than the tenth plan. Funding might take care of capital costs. But recovering operation and maintenance costs will be an enormous challenge. The Delhi government, for instance, charges Rs 2 for a kilolitre of water as against the Rs 9-10 spent on supplying it to households.
But providing water to the poor becomes a convenient alibi for subsidizing the rich. The supplies don't reach the poor who have to pay more for arranging supplies, while the rich waste water.
It is high time we thought of those who are not serviced by municipalities and also cannot afford purifiers. Safe drinking water has to become the legal right.
bis must set a legally enforceable standard for drinking water.
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