India is one of the most water stressed countries in the world. Irresponsible water behaviour and the collective mismanagement of our finite water resources is responsible for our nation’s water crisis. If you use a Reverse Osmosis (RO) water filter in your home or institution or office or you are planning to buy one; this blog is a must read.
HIGH WASTAGE OF WATER FROM RO FILTERS
Reverse Osmosis (RO) is a water treatment process that wastes 3 times water for every one unit of water it purifies. So for every 1 litre of water purified, 3 litres of water goes waste. This high water wastage is the reason the National Green Tribunal (NGT) in May 2019 banned the use of RO filters where the Total Dissolved Solids (essential minerals like Calcium, Magnesium, Fluoride etc) in the water are less than 500 milligram/litre (mg/l). In these water stressed times where most Indian cities are racing towards day zero scenario when water will stop coming from our taps, this kind of insane water wastage from RO filters is criminal when many other smarter water purifying technologies are available.
MISINFORMATION SPREAD BY RO MANUFACTURERS
The National Green Tribunal (NGT) order is based on the reasoning that Reverse Osmosis (RO) as a technology is only meant to treat very high levels of Total Dissolved Solids (TDS) in drinking water. According to the Bureau of Indian Standards (BIS) specification, drinking water is considered below par only if the TDS level of the water is above 500 milligram/litre (mg/l). National Environmental Engineering Research Institute (NEERI), Central Pollution Control Board (CPCB) and IIT-Delhi submitted a joint report to the NGT. This report has come down heavily on the ‘misinformation campaign’ run by RO manufacturers in India. The report trashes claims by leading RO manufacturers in India about RO technology being able to treat water having high arsenic and fluoride contamination. It states that in areas where water source has heavy metal contamination, appropriate contaminant specific technologies should be used so to bring down concentration of these contaminants. “Application of RO in developed countries is limited to desalination i.e. producing drinking water from sea water which is very saline and has an extremely high level of Total Dissolved Solids (TDS). RO companies in India have created a lot of fear and myths among the masses because of which the growing use of RO technology in treating low TDS water has been the new normal when the application of RO should only be ‘limited’ to removal of high TDS water,” the report says.
HEALTH RISK OF DRINKING LOW MINERALISED WATER
TDS i.e the minerals dissolved in water are extremely important for human health. Drinking water with TDS level of less than 150 mg/l is not considered healthy. “Where the TDS level of your tap water is less than 500 mg/l and you put a RO purifier, it reduces the TDS level of the purified water to an extremely low level which is very detrimental for the health of your family. It is like drinking distilled water without any minerals and health benefits,” says Dr. K. Vijaya Lakshmi, Water Quality Scientist and Vice President, Development Alternatives Group in Delhi.
DECIDING WHICH WATER FILTER TO BUY
Dr. K. Vijaya Lakshmi, Water Quality Scientist and Vice President, Development Alternatives Group recommends:
- Before deciding on which filter to buy for your home or institution, always get the TDS level of the tap water and other essential parameters such as bacterial contamination, iron, arsenic, fluoride, heavy metals etc tested from a reliable lab in your town.
- If the test done on your tap water shows presence of any pathogenic bacteria or traces of one or more heavy metals, there are water purifying technologies available in the market to deal with this depending on what pollutants are present in the water.
- RO as a water purifying technology should not be considered as a first option by anyone as it wastes too much fresh water and drinking low mineralised RO water is not good for anybody’s health.
- There is no need of using RO unless your source water is highly saline and the TDS exceeds 500 mg/l.
- As a consumer, do not be gullible and keep in mind that sales folks from the water purifying companies try their best to convince you to buy RO purifiers as these cost a lot more than the non RO filters both in terms of capital and recurring costs (of changing RO filter membranes from time to time).
After researching on different water treatment technologies available in the urban market, I personally think that for dealing with biological contamination in water where the TDS level of your tap water is less than 500 mg/l, a water filter with Ultra Filtration (UF) or Ultra Violet Rays (UV) and a carbon block pre filter (that removes chlorine, volatile organic compounds, odours and unpleasant tastes from water) is an effective option. Unlike RO filters, UF or UV filters do not waste water, retain essential minerals in the water (as they do not reduce the TDS level of the water) but filter out bacteria, viruses and parasites efficiently.
You can check out the following blogs, sites for more information on different kinds of water filtration technologies available for urban and rural areas:
http://www.taraenviro.com/water-segment.aspx (Jal Tara Water Filters)
TAP WATER TESTING KITS
TARA, the social enterprise wing of the Development Alternatives Group has a highly reliable, economical and simple to use product called TARA Aquacheck that can be used by any home owner or institution to test the presence of pathogenic bacteria in water which cause common water borne diseases like diarrhoea, dysentery, gastroenteritis etc. This product has been prepared as per the quality control guidelines of UNICEF, New Delhi. You can visit the following website for more details on this product and other kinds of water testing kits sold by TARA (to test Dissolved Oxygen, Alkalinity, Hardness, Sulphates, Iron, Fluoride, Arsenic & other water related parameters): http://www.taraenviro.com/products.aspx
CHANGING EXISTING RO FILTER TO A NON RO UNIT
If the TDS level of your tap water is less than 500 and you have a RO water filter installed in your home or institution, you can get your RO water purifying servicing engineer to help convert your existing RO filter into a normal filter unit.
- You should first get the water quality of your tap water checked for bacteria and traces of heavy metal from any reputed lab in your city.
- If your tap water has any bacteria present in it, you should get your RO water purifying servicing engineer to check if your existing RO system has UV and UF filters (which help to remove bacterial contamination) installed in the unit. If not, these filters can be easily added to your existing unit.
- The water purifying servicing engineer will take out the RO membrane from your existing RO filter and then your RO can work as a normal water filter which purifies your water without reducing the TDS level of the water and without wasting huge quantities of water in the purification process.
“In October 2019, I had the RO mechanic come to my house for a regular servicing visit and I was talking to him about buying a new non RO filter as the TDS of my tap water was under 250 milligram/litre (mg/l) and I was feeling guilty about wasting so much water in my household as a result of using the RO and giving nearly dead water devoid of essential minerals to my family. He suggested to me that he could just take out the RO membrane from my existing RO system that made it function as a RO unit such that it would then just function as a normal non-RO type of water filter. He told me that my filter unit had a pre existing UV filter so I did not have to worry about bacterial contamination. I agreed. It took my family members 2-3 days to adjust to the new taste of the water which now had more total dissolved solids in it as the RO membrane which was reducing the TDS level to a ridiculously low level (below 100 mg/l) was not present in the water purifier anymore. I am so glad I did this. Every family who has a RO filter should get this done immediately if the TDS of your tap water is less than 500 mg/l,” says Supriya Mohan, a resident of Gurgaon city in India’s water starved National Capital Region.
Dr. K. Vijaya Lakshmi, Water Quality Scientist and Vice President, Development Alternatives Group cautions, “It is extremely critical to keep getting your water filter serviced regularly to ensure efficacy of the filtration process. If you ever see muddy water coming from your kitchen tap, you must immediately switch to boiling of water till you get a technician to come and sort the problem. Boiling water is one of the easiest ways to deal with bacterial contamination in drinking water at home. Ensure that you keep the flame on for 15 minutes after the water starts boiling.”
REUSING RO REJECT WATER
If you do need to use the RO filter in case the TDS of your tap water is above 500 mg/l, please ensure that you collect the RO waste water in a drum and reuse it for any or all of the following purposes:
- Mopping the floors
- Washing clothes
- Cleaning utensils
- Flushing toilets instead of using fresh water
- Diluting with normal tap water and using for watering plants
This film talks about how home makers reuse the reject water from their RO water purifiers and other ways in which families can save water.
Reducing water wastage and respecting every drop of water is the key to solving India’s water crisis and avoid day zero scenarios when our taps will run dry.
For any comments, feedback or clarifications on this blog, please write to the author Neelam Ahluwalia at this email: firstname.lastname@example.org
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