From noxious sludge to clean water

Those of us lucky enough to have water piped into our homes may not give much thought to the complex systems that ensure sewage is flushed out of sight and clean drinking water is always on tap.

Yet across the globe, 1.8 billion people rely on drinking water sources that are polluted with feces. Shockingly, this kills approximately 842,000 people every year.

World Water Day, on March 22, with its campaign "Why waste water?" aims to make us all think a bit more about this vital resource - and galvanize action to ensure everyone has a clean water supply.  

Worldwide, only 20 percent of wastewater is treated before reentering the hydrological cycle. That means water polluted with industrial and agricultural runoff, human pathogens and other harmful substances, is finding its way back into people's homes.

But wastewater need not have such a foul image. With the right management it can actually become a resource, bringing economic, ecological and social, as well as health benefits.

Bangladesh's fight against sludge

One of the places this is urgently needed is Bangladesh.

"Currently, there is no organized sludge management system" in Bangladesh, explains Soumya Balasubramanya, an environmental economist with international agricultural research partnership CGIAR.

In Bangladesh, as elsewhere in the world, many people use pit latrines. "So when the pit becomes full, households either empty the pit themselves and dump the sludge in their own backyards - or they may hire somebody to do this for them," Balasubramanya told DW.

These haphazard disposal arrangements have disastrous consequences that cost the country an estimated 4.2 billion U.S. dollars (3.89 billion euros) each year.

"These losses are in terms of health, primarily," Balasubramanya says. "The raw, untreated fecal sludge increases the burden of diseases, which could range from diarrhea and dysentery, to complex influenzas." 

Balasubramanya was the lead researcher on a new CGIAR study that offers a possible solution. Wastewater and feces would be dealt with through a new disposal system, offered to households for a monthly fee.

Subscription to poo removal, anyone?

Instead of paying around 13 U.S. dollars (12 euros) every three to four years for waste to be taken away and turned into an environmental hazard, 0.31 U.S. dollars a month - the average cost of a local mobile phone contract - sees waste safely collected and put to good use.

The sludge would be transported to a centrally located treatment plant and processed into biogas, or compost.

The study recommends composting waste for use in commercial agriculture - for example on plantations for jute, rubber, and other non-edible agricultural products - or even landscaping.

The advantages of such a system are numerous. Fecal sludge would no longer be a major health risk to people living close to dump sites or rivers. Ecological damage would also be reduced.

Turning waste into cash

And there are economic benefits too. Halting the spread of disease would lower the financial burden on the healthcare system.

Meanwhile, revenue from the monthly subscriptions and bulk sales of compost would give wastewater management providers access to better equipment, so they can offer improved services.

It would also create jobs in new disposal businesses and treatment plants.

Bangladesh has taken action to improve sanitation over recent years. The use of pit latrines is already an improvement for millions of people who previously lacked even these basic facilities.

And last year, the country set up a National Committee for Sludge Management. Balasubramanya hopes that with the committee working to improve public health, systems like this could be launched within the next few years.