Governments must ensure that waste water is treated prior to discharge
There is a famous saying in Hindi: “vaani aur paani har 100 km mein badalta hai” which when literally translated into English, means that in India, there is a difference in language and quality of water every 100 kms. India also has the stark distinction of having 16 per cent of the world’s population, but only 4 per cent of the planet’s freshwater resources. In terms of quality of water supplied to its citizens, India ranked 120th among 122 countries (2010). End result? 38 million Indians suffer from water borne diseases annually. Deaths? A staggering 454,367 as per a WHO report of 2010. Ramesh Kumar Raja had a conversation with Rajul Parikh, President, Water Quality India Association (WQIA) to discuss issues relating to contamination of potable water. Parikh also happens to be Director of Alfaa UV, a market leader in UV technology and India’s first ISO 9001 certified water purification company.
What is your view on impact of falling water tables in India?
Essentially, water used for consumption comes from two sources: groundwater and surface water. Groundwater is water extracted from the earth using bore wells and tube wells. Groundwater is the result of seepage of water from the earth’s surface into the ground. Groundwater is essentially rich in mineral content, mixed with hues of mineral & chemical deposits found in that particular region. Groundwater emanating from natural springs in the Himalayan region is rich in natural minerals (nutrients) which are said to be beneficial for the human body and devoid of impurities. Calcium, magnesium and iron, in well balanced quantities constitute ideal mineral water. However, such pristine sources of groundwater are relatively elusive in areas with high population, agricultural and industrial activity.
It is estimated that about 70 per cent of India’s groundwater is contaminated. Dumping of untreated sewage into water bodies which ultimately seep into surrounding areas, discharge of industrial effluents directly into the ground, and overuse of pesticides in agriculture, have been responsible for groundwater contamination. Over-exploitation of groundwater to meet the demands of agriculture, industry and consumption outside city limits have lowered the water tables to critically low levels. With falling water tables, contaminants and salts dissolved in water (TDS) reach high levels. Punjab, Haryana, Andhra Pradesh and Gujarat have low groundwater tables and face severe pollution of ground water. Contaminants in groundwater are not restricted to chemicals but also include naturally occurring organic chemicals, salts, metals, pesticides etc. Excessive fluoride and arsenic levels in groundwater can spell disaster on the human body with long term usage.
How big a problem is contamination of water in India?
Surface water is found in reservoirs, lakes, ponds and rivers and is essentially rain water. Surface water is naturally soft and contains very few dissolved impurities. Here again, the problem begins with sources of contamination. Discharge of sewage and industrial effluents into water bodies causes serious contamination. (It is estimated that 90 per cent of wastewater in developing countries is discharged into rivers and water bodies without treatment.) Surface waters become the feed for treatment plants operated by civic authorities (municipalities). Post treatment, water is distributed via pipelines to residents within defined urban areas. Ageing pipelines run parallel to sewage lines, the intermittent supply of water, which is the case in most Indian cities, creates a vacuum in unpressurized water pipes, allowing contaminants from the sewage lines to be sucked into the drinking water lines, many of them riddled with leaks. These impurities are pathogenic in nature, mostly bacteria and viruses which cause serious water borne diseases like typhoid, cholera, gastroenteritis and diarrhoea, especially during periods of heavy contamination (eg. floods) leading to outbreaks of epidemics.
So does that mean that the ground and surface water in India are contaminated beyond permissible limits?
Both groundwater and surface water are often contaminated beyond permissible limits. Groundwater may contain more than the permissible TDS and municipal supplies may get re-contaminated during distribution and storage. The level of microorganisms may again exceed permissible levels. Most educated citizens will be able to identify their primary source of water, and this is the beginning. The treatment options available today are based on this fundamental recognition. (While municipalities distribute treated surface water, water supplied by commercial tankers is groundwater and may contain higher levels of TDS)
What are the technologies available to purify the contaminated water?
Filtration, ion exchange, separation and disinfection are four broad categories of technologies available to purify water. Within these, there are further sub technologies, e.g. microfiltration, ultrafiltration, reverse osmosis, and disinfection. Depending on the water quality, separation (membrane) and disinfection technologies are used to create safe drinking water free from excessive TDS and / or microorganisms to adhere to WHO standards of drinking water. Reverse Osmosis (RO) is an effective way to treat water with higher than permissible levels of TDS, which may also contain substances such as fluorides and arsenic. A high TDS level is normally associated with hardness and an undesirable taste. In many cases, the main driver of RO usage is the noticeable change in taste post treatment by RO. RO treated water has a pleasant taste, akin to bottled water. It is important to remember that most RO membranes reduce TDS by 90 per cent. So if the TDS is 600 mg/ml to begin with, the treated water will have a TDS of 60. Ideal TDS levels should be in the range of 60-80 mg/ml. Ground water often contains microorganisms as well, so disinfection post RO is often good protection. (The primary job of an RO membrane is to separate the dissolved impurities, not disinfect.)
When the source of water is surface, filtration and disinfection technologies normally suffice to make the water safe… A chemical based gravity purifier or a chemical free UV purifier does a good job of disinfection. Adding an RO to treat surface water which has low TDS to start with, is normally unnecessary and akin to antibiotic treatment being administered for a common cold.
What can government do to prevent water contamination?
Governments must ensure that waste water is treated prior to discharge. While there are norms in place, implementation is weak. Excessive use of pesticides and chemical fertilizers should be discouraged through education. Incentives to promote organic farming can encourage the use of natural manures as against chemical fertilizers. Under the Swachh Bharat Abhiyaan, monitoring stations have been set up on the Ganga basin to monitor untreated waste in real time. This is a step in the right direction.
What can we learn from other countries in management of water quality?
Contamination at source must be stopped. It’s interesting to see how countries as developed as Australia, to countries such as Thailand and Sri Lanka are proud of their water bodies and make every effort to protect them. Laws and regulations are in place and penalties are high. In the last 10 years, China has made great progress in this area. Another area where we can learn from is recharge of ground water for every extraction that takes place.
Is there something that individuals can do to avoid getting sick because of water contamination?
Microorganisms in water are the number one reason for people getting water borne infections such as Typhoid, Hepatitis and Gastroenteritis. More than 4 lakh people, mostly children, die of water borne diseases every year. India’s tropical climate supports rapid microbiological activity, especially in water and food. Disinfection of drinking water is very important. At the municipal levels, chlorine is traditionally used. However, as water travels across miles of pipelines, some of them very old and rusted, and often running parallel to sewage lines, chances of contamination before water is delivered at your home is possible.
Further, water stored in underground and overhead tanks may elevate the problem. So it’s important to disinfect water at the point of use. Traditionally boiling has been the way of disinfecting water using heat as the disinfectant. But high fuel costs, safety and handling issues, has reduced the popularity of boiling. Chemicals such as chlorine, iodine and bromine are found in many household purifiers today, and are relatively inexpensive. UV is a natural, chemical free disinfectant with no residual properties and provides effective protection against dangerous microorganisms. UV disinfection is a time tested and cost effective solution to provide protection against water borne diseases. In the case of ground water supplies from wells and tankers, where dissolved impurities are found along with microorganisms, a RO+UV purifier can provide the necessary protection.