<p><em>The <a href="https://indianexpress-com.cdn.ampproject.org/c/s/indianexpress.com/article/india/national-drinking-water-survey-cities-samples-9188767/lite/">recent Pey Jal Survekshan reveals that only 10 percent of cities provide safe drinking</a> water to their citizens. Against this background, this article explains the challenges of providing safe drinking water through a centralised piped water supply model. It suggests the need to explore the alternative model of decentralised treatment and non-pipe mode of supply to overcome the issues of water quality in cities in India.</em></p>
With just under 10 percent of cities in India capable of providing safe drinking water to their citizens, the quality of tap water supply is a pressing concern nationwide. This exposes the vulnerability of the piped water supply system and the acute public health risk we are dealing with. Addressing this water quality issue demands a major shift in how we design and operate piped water in cities in India.
<p><em>A safe water source and upgraded treatment facility are not enough for better quality. The main challenge is maintaining water quality at the household-level tap after passing through the distribution network. The water quality deteriorates in the distribution network by multiple processes, such as pipe material release, biofilm formation, sediment buildup, and accumulation of human pathogenic viruses, and this is a global concern even in developed countries [1]. In Indian cities, old and leaky pipes and their exposure to sewer lines further aggravate the contamination problem</em>. </p>
The overburdened city administration grapples with the challenges of ageing water supply infrastructure and lagged repair and maintenance and struggles to balance the funding priorities between restoring existing decaying systems and constructing new ones to meet the growing demand. At the same time, for various reasons, including emerging contaminants, societal expectations have increased from piped water supply, as citizens are more sensitive to water quality. In this context, cities increasingly contend with providing safe drinking water through a centrally managed piped water supply.
<p><em>Meanwhile, over the last few decades, this gap in water quality provisioning has been exploited by two types of market players: companies manufacturing water purifiers and those selling packaged drinking water (PDW). According to estimates, the water purifier market is currently valued at around USD 1 billion, with an anticipated compound annual growth rate of 17 percent over the next few years [2]. This places a significant direct financial burden on citizens. </em></p>
The household dependence on PDW sold in refilled 20-litre jars has also increased tremendously across cities in India. This PDW service model with decentralised treatment and non-pipe mode of delivery has evolved and sophisticated in the last one and half decades, involving a range of market players, including multi-national food and beverage companies (such as Coca-Cola, PepsiCo, Parle Agro, and Bisleri International) and hundreds of local operators.
With an independent water source, mainly groundwater, and an established chain of manufacturers, distributors, and retailers, the PDW service model provides doorstep delivery of safe water to citizens with prompt, reliable, and flexible service.
As per CPHEEO [3] standards, the water requirement in cities in India is 135 litres per capita per day. Under the existing approach of piped water supply, this entire 135 litres of water is treated to meet drinking water quality standards. However, for drinking and cooking purposes, an individual typically needs only 3-5 litres of water per day [4].
<p><em>Hence, the practice of treating such enormous quantities of water with drinking water quality standards and distributing it through a network that cannot guarantee the delivery of safe water at the premise of the citizens needs critical examination. Considering the capital-intensive nature of the distribution network and constraints regarding repair and maintenance, we need to segregate water for drinking purposes and other domestic uses.</em></p>
In this background, the model of decentralised treatment and non-pipe mode of drinking water delivery, followed by the PDW industry, is promising. This model has demonstrated its efficacy, having evolved and stabilised, and now serves a significant population across cities in India. Many municipalities have partially adopted this model by installing water ATMs in their jurisdiction, where providing safe drinking water via a traditional piped network proves challenging (e.g. Delhi and Bengaluru).
The present PDW model raises concerns about affordability and the use of reverse osmosis technology. However, once we acknowledge and embrace this model, exploring alternative, more effective technologies becomes feasible. Indeed, we need more pilots and experiments to evolve appropriate and context-specific institutional arrangements, including choice of technology.
After all, the piped water supply, the only and obvious choice of urban water supply today, has evolved over centuries with a series of technological and institutional improvements. It is time to look for an alternative model of water supply to overcome the water quality issues, and decentralised treatment and non-pipe mode of service delivery is worth experimenting with.
1. America’s Failing Drinking Water System: First, Flint, Michigan; then, Jackson, Mississippi. Communities around the country wonder if their water quality problems will lead to the next national crisis. 5 October 2023. https://www.nrdc.org/stories/americas-failing-drinking-water-system#lead-pipes
2. India Water Purifier Market. https://www.blueweaveconsulting.com/report/india-water-purifier-market-1857
3. The Central Public Health and Environmental Engineering Organisation (CPHEEO) is the technical wing of the Ministry of Housing and Urban Affairs, Government of India, that sets norms, standards and technical guidelines and prepares manuals for urban water supply and sanitation in India.
4. WHO (2005) Domestic water quantity, service level and health. https://www.who.int/publications/i/item/9789240015241
(A version of this article was published earlier in Indian Express dated 28 March, 2024)
Dr Sachin Tiwale is a Fellow at the Water and Society Programme, Ashoka Trust for Research in Ecology and the Environment (ATREE), Bangalore. He can be contacted at sachin.tiwale@gmail.com.