Updated: March 23, 2016 12:02:18 am
Safe drinking water is critical for the safety of our health and that of our children. Even food security does not translate into nutrition security in the absence of safe water. While it is extremely important to build awareness about what needs to be done at the household level to ensure water safety, it is equally legitimate for us to demand safe drinking water from our public systems of delivery. When governments fail to provide this basic requirement, should we be surprised that our children are malnourished and water-borne diseases are on the rise? The challenges of providing safe drinking water are greater in urban settings. India is no exception. But in addressing the challenges, we seem to be focusing mostly on augmentation and much less on quality and safety of water.
It is high time we recognised that safe drinking water in our cities requires that the basic source for supplying water to the city is not only adequate but also clean, and that the city treats its used water (municipal sewage and industrial effluents) before releasing it back to the basic source. Only then can we, backed by efficient systems of delivery, reasonably expect that water availability in households will be clean and safe.
Starting close to home, the river Yamuna ought to be not only the lifeline of Delhi as a basic source of water but also its pride and beauty. Instead, it is badly polluted mainly due to the discharge of much of the sewage generated in Delhi without any treatment. We have built spectacular buildings across the Yamuna with the hope of beautifying the landscape but, sadly, successive governments have looked away from the polluted waters of the river.
Surveys of groundwater in Delhi reveal an increasing degree of microbiological contamination, which is a clear sign of contamination from sewage. Since groundwater is also used by many for drinking, mostly without any treatment, this has grave implications for the health of those dependent on groundwater.
Delhi’s growth has fast outpaced its ability and willingness to extend the sewerage network and treat its sewage or wastewater. While 55 per cent of Delhi is technically connected to sewerage systems of pipes, and this is much larger than the average of 32.7 per cent for all Indian cities, this does not include thousands of unauthorised colonies or illegal slums which are not taken into account when service delivery is planned and implemented.
The sewerage networks are supposed to ensure that sewage from flushed toilets travels through underground sewer pipes until it reaches a sewage treatment plant. After primary treatment, the sewage is supposed to be preferably reused for consumption in gardening, toilet flushing, etc, or discharged into natural stormwater drains which should ultimately drain into the Yamuna.
In the absence of complete coverage of the city with a sewerage network, natural stormwater drains are being used as sewers. The result is that Delhi’s very extensive natural drainage system is being eroded fast, as documented in the excellent recent reports and studies by Professor Ashvin Gosain of IIT Delhi. There are 22 natural drainage systems that outfall into the Yamuna in the Delhi stretch of the river, which is 22-km long. Besides providing a safe exit to stormwater, including floodwaters, natural drains recharge groundwater and also support biodiversity. Many of these are getting encroached on and are disappearing. Others have been converted into nallahs that carry untreated sewage throughout the year. Sewer pipes punctured during repairs also send sewage to stormwater drains. In Gosain’s words, “If Yamuna is to be made pollution free, then these stormwater drains need to be freed of pollution first.” This has the added benefit of restoring the catchment area in the city.
As regards sewage treatment, only 30 per cent of the sewage generated in Delhi is treated before discharge. Even though this again is higher than the national average of 19 per cent for all Indian cities, the installed capacity of the sewage treatment system is insufficient to take care of even the area that is covered by the sewerage network. Moreover, the capacity is underutilised for a number of reasons, including the fact that even when there is a sewage treatment plant, it is not always possible for sewage to be conveyed to the plant. As for the 45 per cent of Delhi which is unconnected, in any case, sewage travels through the natural stormwater drains to the Yamuna. The challenge is even greater in the walled city of Old Delhi, which has combined sewers, designed to carry sewage as well as storm water, a legacy that is not in line with current good engineering practice.
The Delhi Jal Board has been trying for some years to find an intermediate solution through interceptor sewers along the Najafgarh Drain, the principal hub of untreated sewage in Delhi, and also supplementary and Shahdara Drains. The idea in the case of the Najafgarh Drain, for example, is to divert untreated sewage coming from the surrounding unauthorised colonies which would otherwise flow into the Najafgarh Drain. But progress is slower than expected and an additional challenge is posed by the backflows from Gurgaon in Haryana into this drain. Most recently, the government of Delhi has committed to extending coverage of the sewerage network to around half of the unauthorised colonies. This again would need time, money and political will.
With multiple agencies present, it is not clear who is responsible for making the whole system work to respond to the enormous challenge of delivering safe water to the residents of Delhi. While drinking water and the sewerage network are the responsibility of the Delhi Jal Board, stormwater drains are under the different municipalities, the Public Works Department or the Irrigation and Flood Control Department of Delhi, depending on their size, and encroachments are to be taken care of by the Delhi Development Authority. One good development is the rise of a single regulator, the National Green Tribunal (NGT). What we need in addition is a single public authority suitably empowered and responsible for the delivery of safe water with whatever it takes. Such an entity should be accountable to the people and able to respond to the NGT in one voice.
📣 The Indian Express is now on Telegram. Click here to join our channel (@indianexpress) and stay updated with the latest headlines