New technology to ensure access to improved sanitation

Bangladesh has made great strides in ensuring improved sanitation in recent years, but nearly half the population still do not practise hygiene.

The Biofil technology of Ghana can help Bangladesh in this regard.

The experience of a pilot project involving the Biofil technology in setting up toilets was shared at a workshop at The Daily Star Centre yesterday.

The technology was tested in slums in Dhaka city for a period of about two years under the project -- SanMark City.

Biofil technology relies on earthworms for decomposition of faecal matter. The toilets will have a lifespan of 25 years.

A digester is set in a chamber or tank made of Ferro-cement or brick, which could be laid above or below the ground level, depending on flood or ground water level of the location.

In the digester of a Biofil toilet, the faecal solids are converted into vermicompost—the product or process of composting using various worms—that builds up slowly and is safe to handle.

In the digester, the faecal matter is retained on the top of the filter and is digested by tiger worms, while the liquid drains through the filter media.

The liquid effluent from the digester then flows into a soakage pit for infiltration of liquid into the subsurface. The toilets are designed to utilise the subsurface infiltration capacity of soil.

The toilet needs to be flushed with about two litres of water after every use and only water and brush can be used to clean the toilet. Use of chemical cleaning agents is strictly prohibited.

Policymakers, practitioners, non-development organisations, engineers and users preferred the Biofil technology, saying it might be suitable for Bangladesh as they are cheaper, eco-friendly and easy to maintain.

“This can be important from a health and hygiene point of view. But if it is costly, it will not be affordable,” said Fazle Rabbi Miah, deputy speaker of parliament.

Setting up toilets using the Biofil technology will cost Tk 8,000 to Tk 10,000, said Mumtaz Arthur, a director of Biofilcom, Ghana.

This is compared to about Tk 2,000 for a basic toilet promoted by the government and non-governmental organisations, Tk 7,000 for a double pit latrine, and Tk 70,000 for a septic tank.

Heleen van der Beek, country representative of ICCO Cooperation, said the cost of the Biofil technology is higher at the initial stage.

"But they require less maintenance, chemicals and cleaning materials. It takes care of the faecal sludge, meaning it will not harm the environment. So, there will be long-term benefits over the life time of the toilet."

Along with International Development Enterprises (IDE) and Dushtha Shasthya Kendra, ICCO Cooperation has been implementing the pilot project since January 2014 with financial support from the Bill & Melinda Gates Foundation.

The International Training Network Centre of Bangladesh University of Engineering and Technology has evaluated the technology since the inception of the project.

Experts said, except for a small part of Dhaka city, the entire country is served by on-site sanitation facilities such as pit latrines and septic tanks, but these have been developed without much attention to the management of faecal sludge.

In the absence of faecal sludge management, pit or septic tank contents are often drained to low-lying areas, posing significant risks to environment and public health.

“Biofil could be a promising sanitation option in areas currently served by pit latrines in both urban low income communities and rural areas,” said Azizur Rahman, research officer of the ITN Centre.

“It could solve the problems associated with faecal sludge management of these traditional toilets.”

Two users said Biofil toilets are easy to maintain and do not require much water.

Besides, mosquitoes are not born in the toilet.

Conor Riggs, technical director of IDE, said the prices of the Biofil technology can be brought down if the company of Ghana ties up with local firms to produce the toilets.

FM Sarwar Hossain, project leader of SanMark City, moderated the workshop.