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Precious waste

December 7, 2011

Climate change, growing populations and energy-intensive agriculture are all increasing the pressure on the planet's water resources. Making better use of waste water could help ease the problem.

https://p.dw.com/p/13NWb
A river full of garbage
Waste water too can be a precious resourceImage: DW/Anne Herrberg

Here in the West, what's the first thing we do whenever we want to make tea, clean the kitchen or water the plants? We turn the tap on. We take clean water for granted.

But populations in many parts of the world have no such luxury. According to the United Nations, over a billion people lack access to clean drinking water and over two billion – one third of the world population - lack access to basic sanitary facilities.

The problem is worsening. Water is becoming increasingly scarce as the world population continues to grow, industries continue to devour the world's natural resources and climate change continues unchecked.

The Intergovernmental Panel on Climate Change (IPCC) estimates that by 2025, freshwater reserves will have dropped by 50 percent in developing countries and by 25 percent in industrialized nations.

Poor water quality

There's much at stake. Water, after all, is essential for humans' survival. As Erik Harvey from British NGO WaterAid says, access to running water is a prerequisite for development.

"A lack of drinking water can lead to children missing school and adults failing to get paid work because they are too busy collecting water from the nearest river or well, " he says. 

A young girl drinks water from a tap
Clean drinking water remains a luxury in many parts of the worldImage: CC/waterdotorg

But it's not just a scarcity of water that's the problem, but also the quality of water.

Most of the water used by populations in poor countries is contaminated and a major cause of illness and disease. Creaky, substandard sewage disposal systems are often to blame with slurry polluting the surface water that people use as drinking water.

The consequences of contaminated water

The World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) blame 80 percent of diseases in developing countries on contaminated water, and stress that the hardest hit are children.

"Approximately 17 percent of worldwide child mortality rates are caused by diarrheal diseases – more than deaths caused by malaria and HIV taken together, " says Therese Dooley, a hygiene expert with UNICEF.

The international community has recognized the urgency of the problem and made access to clean water and efficient sewage disposal systems a Millennium Development Goal (MDG).

Ethiopians on donkeys search for water
Many people have to trudge for miles to get waterImage: CC/waterdotorg

"But this is probably the most unrealistic of all the MDGs," Dooley says.

Water pays

Investment in water treatment systems and infrastructure makes perfect sense. According to the World Heath Organization,  every dollar invested in water supplies and wastewater treatment will yield a return of seven dollars.

But even though the situation is still dire, it‘s not for lack of trying, says Ned Breslin, CEO of US non-government organization Water for People.

"There is enough money and there are plenty of projects, but efforts tend to be concentrated on the technical side of things," he points out. "They see that people have no clean water and say: Oh, let's build a pump.  But it's not that simple."

People near a sewage system in Bukasa
Contamined water is a big killer in developing nationsImage: CC/Paul Evans-GR&B

In his opinion, these projects need to be supervised and local populations need to be more involved. They need to accept the project and be willing to assume responsibility for it.

"Then at some stage they will no longer need the help of an NGO again," Breslin says.

Not wasting waste

It's important to build good sewage systems but what's just as crucial, experts say, is to make better use of waste water.

Separating water according to its contamination levels is a crucial part of the process. Rainwater, for example, requires less purification than water contaminated with feces. 

The purification process if a complex one but one made significantly easier were these different types of wastewater separated from the outset. That way, rainwater could be filtered and reused as drinking water with relative ease. 

Many new water treatment systems are affordable because they do not depend on outside energy. The required energy is generated by heat exchange between water flows or fermentation with the help of bacteria.

Untreated water contaminated with feces can also be reused, for example as fertilizer or in biogas and biomass plants. The think-tank Water, Sanitation & Supply Collaborative Council estimates that China is now home to some five million mini biogas plants that recycle household and human waste to generate energy. It's a promising beginning albeit a modest one, given that the country has1.3 billion inhabitants.

A water treatment plant in India
Local populations need to be involved when water treatment plants are builtImage: KfW-Bildarchiv/Fotograf:Joachim E. Roettgers

But such systems are also an opportunity for people to actually make a profit by selling the fertilizer they have made and the energy they have generated at local markets. Many NGOs in countries such as Bangladesh and Ethiopia therefore offer support in the form of microcredit.

That way, waste water becomes a resource that helps them improve their living standards.

Michaela Führer (jp)
Editor: Sonia Phalnikar