As the Mystic River winds its way into Boston, raw sewage is frequently visible. This New England river may have been blessed with a poetic name, but it no longer has water quality to match thanks to a high rate of “sanitary sewer overflows” (SSOs) – incidents where heavy rain, poor maintenance or vandalism cause untreated sewage to be discharged into surrounding waters.
On a single day last December, over 3.9 million gallons of contaminated rainwater poured into the Mystic River, according to the local water authority. Streets flooded with toilet paper and sewage are all too common a sight during these overflow events.
America’s environmental watchdog estimates the country sees between 23,000 and 75,000 SSOs each year – and it’s not alone. Across the world, both developing and developed countries struggle with public health and environmental problems caused by inadequate sanitation systems.
Poor access to clean toilets is high on the list of problems, and it’s an issue the world has long recognised. Nearly 15 years ago, the international community launched the United Nations Millennium Development Goals (MDGs) in a bid to improve economic and social conditions worldwide. Among the goals was a target to transform the world’s toilets, halving the proportion of the global population without access to “improved sanitation” – a category that ranges from protected pit latrines to flush toilets – by 2015.
It was hoped this would see the pool of people without access to clean toilets drop from 53% in 1990 to 26% of the population. A glance at the official figures would suggest the world is making progress on this goal. As of 2010, 4.3 billion people (62%) were using an improved sanitation facility and 2.6 billion (38%) were not, according to UN estimates. Projecting this trend out to 2015 would result in 33% of the global population lacking an improved sanitation facility, and a shortfall of seven percentage points from the goal – not too bad.
But there’s a problem. According to the current definition, “improved sanitation facilities” include those that discharge untreated sewage into the environment. Any facility that safely separates human excreta from human contact is considered improved.
These facilities include toilets that discharge untreated waste away from the user, but perhaps back into the environment, contaminating someone else’s backyard or other waterways. If your neighbor’s toilet is discharging waste, it may be carried away from their home, but it may also end up harming the community down the road, re-entering drinking water supplies or waters where people swim, affecting irrigated crops or coming into direct contact with people in other ways.
For these reasons, toilets that discharge untreated sewage into the environment must be considered unimproved. When they are, progress on the 2015 target becomes more a cause for concern than celebration.
Most of the world lacks access to clean toilets
Using this more stringent definition, the figures look very different: as documented in our recent study in the journal Environmental Science and Technology, 2.8 billion people (40%) were using an improved sanitation facility as of 2010 and 4.1 billion (60%) were not. That’s an extra 1.5 billion people in the pool of people with inadequate facilities.
The redefinition also increases the baseline population using unimproved sanitation in 1990 to 64% (up from 53% under the current definition). The corresponding target increases as well to 32%. Projecting out the redefined trends, the 2015 goal year would result in 59% of the global population using an unimproved sanitation facility, a significant shortfall on the target.
It’s shortfall that should raise alarm bells.
While slight changes in definitions may seem trivial, the hazards of not having access to toilets are not at all. Sanitation is a cornerstone of health, environment, wealth, and dignity. Without toilets, poor sanitation leads to diarrheal disease, killing 760,000 children every year – the second leading cause of death in children under five.
The environment suffers as untreated sewage leads to contaminated environments, destroying ecosystems, polluting clean water sources, dwindling available drinking water supplies and further spreading disease.
Wealth also gets stunted: the World Bank estimates that economic losses from inadequate sanitation worldwide total US$260 billion annually. And the dignity of individuals is stripped away when they have no choice but to defecate in public.
However, there are signs the international community is beginning to recognise the importance of improving sanitation for both protective public health and environmental benefits beyond just the user.
An interim report from the Millennium Project’s task force on water and sanitation highlighted the need to extend the definition of improved sanitation, “ensuring a clean and healthful living environment, both at home and in the immediate neighbourhood of users.” As Malcolm Langford, a research fellow focusing on the human right to water and sanitation at the Norwegian Center for Human Rights, has said, sanitation facilities should “protect the user, the locality (e.g., households, school, workplace, hospital or community) and wider population from the adverse consequences of contamination.”
Coping with China’s megacities
Growing populations, urbanisation and ageing infrastructure will demand an even greater effort to improve sanitation in the future – and China is on the frontlines. With its population of more than 1.3 billion and rising, the country will have to ensure that its sanitation technology is able to meet the needs of larger populations and that its sewage treatment systems will not be overworked, and therefore less effective at removing pathogens.
As of 2010, 64% of China’s population had access to an improved sanitation facility, according to the current definition. But the country’s leaders face an uphill struggle to ensure clean toilets for all.
Government targets suggest they recognise this, though paper goals don’t always become reality. China has been busy building new sewage treatment plants to cope with the rise in domestic sewage of about 1.52 billion tonnes each year since 2001, and had more than 1,600 facilities under construction as of 2010. But it fell far short of its aim to install 160,000 kilometres of wastewater pipelines during the 11th Five-Year Plan (2006-2010), with only 70,000 kilometres completed by the deadline.
A lack of pipeline capacity poses a continued threat to China’s water quality as any untreated sewage the system cannot handle may end up polluting the country’s already significantly stressed water sources. China’s urban sewage treatment rates were estimated at 75% in 2010 and are expected to rise to 85% in coming years. Higher rates will only be effective, however, if complementary piping is developed to handle larger sewage loads.
Moreover, as people continue to pile into China’s cities, overcrowded areas must be sure they can handle the rising numbers. Since 1990, the number of urban residents has doubled and more than half the population now lives in cities, placing new and inevitable stresses on sanitation systems.
