Recently the Ministry of Environment, Forests and Climate Change (MoEFCC) (Government of India), issued a draft notification to regulate the use of membrane-based water purification systems, especially in those areas, where the water quality of the source, meets the drinking water potability criteria as specified by the Bureau of Indian Standards (BIS). The draft notification which is yet to get a public approval, was published by the ministry in response to a directive issued by the National Green Tribunal (NGT), last year to ban Reverse Osmosis (RO) based water purifiers in areas where the count of Total Dissolved Solids (TDS), which includes trace chemicals, salts, viruses, bacteria etc., at the source level of the supply is less than 500 milligrams per litre. This directive of the NGT was challenged in the Supreme Court by the Water Quality Association of India, which is an organization representing all the companies that manufacture RO based water purification systems but the Supreme Court upheld the NGT order.
Reverse osmosis water purifiers waste almost 70-80% water during the purification process. RO are hugely popular, and this has led to massive wastage of water. Most people are unaware of the fact that demineralization of water is not required if the TDS in the input water is less than 500mg/litre. Because of this reason NGT has asked the centre to ban RO water purifiers in places where water supply has TDS lower than 500mg/litre.
RO based water purifiers uses a multi-staged process of purification of water involving technologies like activated carbon components, arrays of membrane etc. in the filtration process. Thus, they can effectively filter out a large number of inorganic (like arsenic, fluoride etc.) as well as organic components (like bacteria etc.). In principle it uses the phenomenon of osmosis, to separate the harmful solutes from water, so that the water can be made fit for drinking.
Main Highlights of the Draft Notification of The Centre
The draft notification prohibits the use of Membrane Based Water Purification Systems (MWPS), in those areas, where the water meets the potability criteria as specified by the current BIS regulations (10500:2012). As RO systems are based on MWPS, so this order, if implemented will basically apply to them.
The current BIS regulations accept a TDS count of around 500-1200 mg/litre in water, to be considered safe for drinking.
The draft notification also directs the use of the filtered water, obtained from the RO purifiers, only for the purpose of drinking. The wastewater, i.e. the water rejected by the purification process, should not be discarded but should be collected and used for purposes other than drinking (which will in turn be prescribed by Central Pollution Control Board (CPCB)). The guidelines issued by the NGT however sets a deadline of recovering 75% of water in the RO based purification process, by 2022.
The draft notification by the Environment Ministry directs that the Commercial and Industrial installations of the RO based systems must operate according to the provisions of The Water (Prevention and Control of Pollution) Act, 1974.
The draft notification puts the onus of laying down a system for monitoring, assessment and certification of the RO based water filters on BIS. It also lays down the rules that the manufacturers and importers of RO based systems, must keep in mind.
The CPCB will be the nodal agency for enforcement of these rules. Monitoring of the compliance of these rules will be done by CPCB in association with the pollution control boards of the respective states.
The draft also specifies that the waste elements of these RO filters shall be disposed according to the provisions of the Plastic Waste Management Rules 2016.
Possible Impacts of the Implementation of the Draft Notification
The rules of the draft notification when implemented will affect all the stake holders, which includes: domestic consumers, commercial units which supplies bottled drinking water, the manufactures of the RO purifiers and the authorities in charge of managing the water supplies to the domestic households.
Firstly, the domestic consumers, are effectively prohibited from installing RO based water purifiers in areas where the CPCB certifies the water supply to be compliant with BIS standards. While there are no provisions for legal prosecution against the consumers in case of non-compliance, but the authorities may take other actions like confiscation of the water systems, levy fines etc.
Secondly, the commercial units, which supplies bottled water must create infrastructures, to store water that is lost in the purification process in an environment which is “safe” and “hygienic”. Also, these units are required to maintain a record of the quantity of water that is wasted in the purification process.
Thirdly, the authorities in charge of managing the water supplies to domestic households are required to upgrade their infrastructure and supply only BIS compliant water to the households.
Lastly, the manufacturers are required to modify the designs of their water purifiers so that not more than the prescribed 25% of the water is wasted in the purification process. Also, these water purifiers should have the provisions of displaying the TDS levels at both the entry and outlet levels of the purifiers. The technology up gradation will therefore make the water purifiers costlier for the consumers than what it is today.
Arguments in Favor of the Ban
1.The RO based home filters are found to waste nearly 80% of water in the purification process. This is mainly because the water is purified by using a multi-staged process.
- Research shows that these purification systems also reduce the levels of vital nutrients like calcium, magnesium etc. in the purification process.
- Research also shows that these purifiers are also ineffective to completely remove some of the harmful microorganisms like Hepatitis E virus etc.
Arguments Against the Ban
- Some manufactures have argued that the TDS limit of 500 gm/l that is allowed by the current BIS standard is not sufficient to treat the water to be qualified as potable as the water may still contain harmful substances including some toxic heavy metals, pesticides, micro plastics etc.
- Some home water-purifiers already have inbuilt mechanisms to recover 50-60% of the water and some commercial water purifiers have built mechanisms to recover an even higher percentage of water. So, imposing a blanket ban on all RO based water purifiers will not be a fair and just measure on the part of the government.
- Ban on RO purifiers will have an adverse impact on industries like pharmaceuticals, which rely largely on purified water. And therefore, this initiative may prove disastrous to all stakeholders including the citizens of India, especially at a time like this, when the country is in the midst of the COVID pandemic.
- Our present infrastructure of our country is not adequately equipped to supply safe and potable water to all consumers, as has been shown by recent studies on piped drinking water in the different major cities of India by BIS. The huge population of India makes it logistically very difficult for the authorities to even monitor the quality of piped drinking water at all levels, let alone take measures to supply high quality potable water.
Conclusion and the Way Forward
Water purifiers are very important tools for all the stakeholders and especially the domestic consumers, to get potable water to meet their daily needs. But the present purification technology that is in the market, i.e. the RO based water purifiers also have some research backed serious drawbacks, some of which have already been highlighted in the article. Therefore it imperative to seek for solutions to address the issue in a balanced way which will include not only reducing the water wastage, maintaining TDS levels such that all the essential nutrients are preserved and all harmful microorganisms eliminated, but also the water purifiers within affordable range of the consumers especially the domestic households.
Manufacturers are already looking at alternative technologies like: Biotron, G tech, Ionized alkaline water etc., which have research backed evidence of reducing water wastage and preserving the requisite TDS levels, and have started research and development to bring these technologies within the affordability range of the consumers.
Initiatives like rainwater harvesting can also be useful at the domestic level for getting potable drinking water.
The water supply authorities, on their end must also ensure regular maintenance of the distribution pipelines both at the source and consumer levels and for this to happen there should be an effective support from both the state and central government.
The central government should also commission more and more BIS certified labs for the effective monitoring of the quality of water distributed to the consumers by the distribution authorities.