How safe is the water that is supplied in our homes?

11 Sep 2018

Understanding groundwater contamination in India - Conversation with Anshuman, Associate Director, Water Resources, TERI

Understanding groundwater contamination

Q. Is the water that we use affected in anyway?

A. The water that reaches our homes is supplied through various channels. Now, when you ask if the contamination is a recent phenomenon, the answer is of course, not. This has been for years now. India is a country in which we have had persistent problems with groundwater. Many regions in India do have prominence of a few contaminants like fluoride, arsenic, and nitrate to some extent, and in some places we have salinity, which means high salt content in water. And, in some cases you have high industrial discharges and activities, which are basically discharged just over ground or the surface and leech down to the groundwater, sometimes adding to the heavy metals, pesticides and those kinds of things. This is probably because of the mismanagement of waste water.

Q. How risky is it?

A. Well, it's not true always and everywhere. There are a few recent news reports that talk about the surface run-offs of nutrients such as nitrogen, phosphorus, and also the pesticides from agricultural fields. Again, that is a phenomenon in existence for long. The fact remains that there are various places across the country which face this kind of situation. Here in cities, we get pipe water supply which comes through a treatment system. So let's say when a water supply body such as Delhi Jal Board or a municipal corporation would source water from the ground, they treat it before sending it across.

Now, how much that treatment is effective or if there is a problem in the supply is on case by case basis. It is not that it is very uncommon. You will come across reports of contaminated water over a period of time in various parts of the country. But usually in cities the water is treated, whereas in rural areas the reliability is more on groundwater being used directly for consumption, and thus the risk is very high in case of contamination.

Q. So despite the treatment, the water quality falls below mark. What do you have to say about that?

A. See, the commitment is to have completely safe water supplied to households, but there are times when it does not happen. Now, there are reasons for it. If you look into our supply system, the dilapidated infrastructure which we have, the water mixing happening due to co-existence of sewer and supply water lines in many areas and probably poor maintenance of the reservoirs, it is a combination of various factors. So it's not just the groundwater, by the way.

Q. So are there logistical/administrative reasons to it?

A. The reasons for the bad quality of water in urban water supply systems would be many. Like I said, if the reservoirs, overhead tanks are not clean, then you would have a different kind of issue cropping up; if the treatment is not done effectively from the source by the plant, then of course you'll see elevated concentrations of the contaminants, and so on and so forth. So it is a matter of overall infrastructure and its effective maintenance. Groundwater is just one of the sources of water supply.

Q. What are the steps that urban local bodies take in case of contamination to ensure our safety of health?

A. If something fails somewhere, then there are stopgap measures that authorities implement, such as restricting the supply for some time till the contamination levels reduce in a certain supply channel. The measures could be of any kind. But ultimately it is a failure in the system of treatment and supply both, so one has to look into that; also into the source of water. So it is a complete measure. And then of course, the distribution system has to be taken care.

Q. Is there anything at the household level that we can do to improve the quality of water we use, in the short term or the long term?

A. There are many things that can be done. For example, now there are efficient systems available in market which can give you at least some parameters to monitor the quality of water on the ground. So that can happen at the RWA level. If something comes up, it can be reported to the local authority. The second thing is one can possibly have an effective second tier of treatment systems in there RWA, depending upon their need. But primarily the responsibility of good drinking water lies with the government because they are the ones who are supplying it, especially in the urban areas.

Ground water
Water management
Water pollution