Editorial Perspectives: innovation needs for the water sector in India to achieve sustainable development goals

Introduction

The average annual per capita availability of water in India is estimated to be 1117 m³ in 2014, making India water stressed. Almost 70% of India's surface water resources are contaminated by various toxic, biological and other pollutants because of the lack of adequate infrastructure for wastewater management. Sixty percent of groundwater sources have problems either with availability or quality or both. These water quantity and quality issues are having a significant bearing on the environment, ecology and health of India's population. It is pertinent to note that about 1.3 billion Indian people live in 2.4% of the world's geographical area. Added to these, climate change is expected to significantly impact India in terms of increases in sickness and death, and increases in the vulnerability of densely populated areas in coastal regions. It cannot be over emphasized that India will be facing sustainability challenges on a scale which is orders of magnitude more than that of most other parts of the world, as it pushes its development agenda. Thus there is urgency for addressing a variety of research issues in the area of water and the environment, which are unique to India because of its hydro-climatic, social and economic conditions, and population. These research needs are of importance from a global perspective too because India is the world's seventh-largest economy, and it is among the world's fastest growing economies. Several of India's environmental problems will have global implications. Also, instead of reinventing the wheel, many of the solutions for water environment problems found elsewhere in the world can be translated to India, if innovative research is carried out for adapting them to the challenging Indian conditions. Simply put, if India achieves its target of sustainable development goals, especially SDG-3 (good health and well-being) and SDG-6 (clean water and sanitation), more than 20% of humanity will have also achieved them. Herein, we discuss three key areas of water research, which are important from the Indian perspective and also require global effort.

Development of affordable technologies for clean water

It is estimated that 76 million people in India do not have access to safe drinking water and about 80% of the Indian population depends on groundwater. 17.8 million people in India are affected by arsenic-contaminated groundwater while 9.8 million are affected by fluoride-contaminated groundwater. Other groundwater contaminants of significance are iron and perchlorate. Although several technologies are presently available for treating surface and groundwater contaminated with different pollutants, more research is needed to develop technologies which are cost effective and amenable to large scale deployment in situations where fine control is not possible. Research should be carried out to answer the following questions. (a) What modifications are needed to apply to existing technologies on a massive scale where fine controls are unavailable? (b) How can the existing technologies be adapted using locally available materials and traditional knowledge? (c) How can drinking water quality be assessed in a completely decentralized or onsite system in a large country like India? (d) How can one increase the availability of clean water from the existing resources? (e) How can the source water quality be protected to minimize risks and need for treatment of existing supplies? (f) What are the ways to make industries (textile, distillery, paper and pulp, tannery, chlor-alkali) sustainable with respect to water management?

Monitoring and assessment of the impact of emerging contaminants (ECs)

About 50% of the generic drugs used in the world are manufactured in India. Also, out of the total drugs consumed in India, only 50% of this consumption is based on a doctor's prescription. The pesticide usage in India during 2016–17 was on the order of 63 340 metric tons. Large amounts of pharmaceuticals and pesticides are finding their way to water bodies and will have a significant effect on the environment. Compared to other countries, the effect of these contaminants will be more severe in India as the majority of the wastewater does not get treated and the hygiene and sanitation conditions are still not satisfactory. Concentrations of emerging contaminants (in the order of μg L⁻¹) in India are several orders of magnitude higher compared to other countries. The presence of antibiotic resistance genes and super bugs are reported in many parts of the country, and this is a major global threat. In this context, finding answers to the following India-centric research questions is important. (a) What are the fate and impact of ECs in decentralized and onsite sanitation systems, (b) what is the fate of ECs in water sources and sediments, which are also contaminated by easily degradable organic matter, (c) what concentrations of emerging contaminants can trigger antibiotic resistant strains and how can one control these, (d) how can the existing conventional treatment systems be retrofitted to address the issue of ECs, (e) what is the implication for large scale recycling of treated wastewater (to address water scarcity problem) from the perspective of ECs and (f) what are the ecosystem and population-scale human health implications for the proliferation of ECs in India's water resources?

Maintenance of river health

Major rivers in Northern India are fed by glacier melt waters, and those in Southern India are fed by monsoons. It is well established that climate change will have a significant impact on the frequency of extreme events, and cause temporal and spatial variations in the availability of water. This will make water resources vulnerable and will have bearing on India's climate change adaptation strategies. While much research is being carried out on the impact of climate change on water resources from a quantitative perspective, research on the impact of climate change on water quality in India is in its nascent stage. Significantly more research needs to be carried out to estimate the impact of (a) climate change on ecological flows in rivers and on in-stream biota and (b) different climate change adaptation measures on river health, in the context of hydro-climatological factors unique to India.

Closure

To achieve the sustainable development goals with respect to water and health in India, a lot needs to be done. The water and environmental problems faced by India are different from those of other nations in scale, because of hydro-climatic, social and economic factors, and because of the large population of India. These problems will have global impact if left unresolved. A concentrated effort by researchers across the world can come up with affordable and sustainable solutions, which will have positive global implications as well.

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