Tuesday, September 26, 2017 | ePaper
Why water quality matters as much as quantity
We know the world has water problems. The recent drought in the Horn of Africa left at least 20 million people without access to secure drinking water. Globally over 800 million people still lack access to even a basic drinking water service. Too much water can also be catastrophic. In Sierra Leone, heavy rain caused a mudslide that swept away homes, killing nearly 500 people. In India, Nepal and Bangladesh, intense monsoonal floods have left over 1000 people dead. And in Texas, USA, record rains associated with storm Harvey have displaced tens of thousands of people.
But while the global conversation on water tends fixate on water quantity - too little or too much - another, more insidious problem can lie hidden from view: water quality. Lakes and rivers covered with luridly coloured algae are the exception. More often, problems are invisible.
Sometimes the problems are 'natural' and caused by chemicals such as fluoride and arsenic that are already present in rocks and sediments. Last week, for example, the BBC highlighted the widespread contamination with arsenic of groundwater in Pakistan. Tasteless and odourless, arsenic is a poison; it can accumulate in the body causing a variety of chronic health problems, including cancer. The authors of the original research estimated that 60 million people were living in 'high risk' areas.
Issues around water quality and health also figure prominently in ODI's 10 things to know about the future of water and sanitation, launched last week to coincide with World Water Week in Stockholm. We highlight our work with the British Geological Survey (BGS) and others, published recently in Nature Geoscience, indicating that over half of the groundwater potentially available in the Indo-Gangetic basin, spanning Pakistan, India, Nepal and Bangladesh and home to more than 750 million people, is contaminated with salt or arsenic. Across the basin, declining water quality rather than falling water tables is the main concern for farmers and domestic users.
Where people drink water laced with arsenic or other natural contaminants, there are no easy solutions. In the case of arsenic, the best option is to identify and use only safe sources, if necessary piping good quality water to households or communities. The alternative is to help people treat the water before drinking. Both present major challenges in places where millions of poor people self-supply water from their own sources, and where treatment options are costly or complex.
Where contaminants are introduced into water bodies from wastewater and excreta, agricultural chemicals or industrial spills, prevention is key. In other words, ensuring that polluting activities are stopped before problems arise and become costly to deal with. In practice, monitoring is often absent, or policy-makers turn a blind eye to problems and make access to information difficult. China's environmental woes provide a salutary reminder of the costs - in economic and health terms - of inaction. Official data indicate that over 30% of monitored rivers are now unfit for drinking, or even human contact. In the densely populated North China Plain, fewer than 30% of shallow and deep groundwater sources are classified as drinkable. Environmental degradation costs the country perhaps 5% of GDP. Faced with growing public concern over the state of the environment, in 2014 Premier Li Keqiang declared a 'war on pollution', elevating the issue to one of national security.
So what can be done? Policy-makers could go a long way to addressing at least part of the problem by 'talking shit'; making sure everyone has access to a toilet, and to a sanitation service that safely captures and manages waste. Better still, policy-makers should aim for the waste to be separated, treated and reused - turning it into useful by-products for use in a 'circular economy' of energy and nutrient recovery.
This is another of the key issues for the future we highlight, although there's clearly a very long way to go. Latest estimates suggest over 60% of the world - that's 4.5 billion people - currently lack a safely managed sanitation service. The burden of ill-health, indignity and time-poverty this creates falls overwhelmingly on women and girls, sometimes in unappreciated ways. For example, when children get sick with water borne diseases, the care-giving burden on the mother increases. Women are more likely to be responsible for water purification at the household level, and more likely to handle contaminated water. And pregnant and lactating women are more susceptible to some diseases.
Whatever the policy response, a critical first step is to recognise that freshwater quality is intimately bound up with health, poverty and broader economic outcomes. Floods and droughts provide some of the most visible reminders of the water risks people face, but it is the hidden, slow-burning crisis of water quality that we must open our eyes to.
(Roger is Head of the Water Policy Programme and an Honorary Research Associate at the British Geological Survey).