Johkasou Tank is a decentralized wastewater treatment system that treats human waste from flush toilets and domestic wastewater from kitchens, baths, and others.

In an attempt to instil a sense of ownership in handling one’s own sewage wastewater, Bhutan Toilet Organisation (BTO), started the pilot project to install the first Johkasou Tanks in Thimphu yesterday. 

The tanks sponsored by JOYLET Japan, are expected to be an alternative to a central sewer system that is difficult to develop in Bhutan, due to the geographical landscape and rugged terrain. 

BTO’s Executive Director, Passang Tshering, said that currently, many households in Bhutan do not have access to proper sewer systems, causing overflow, mostly observed in towns during monsoon. 

The overflowing sewer systems are directly connected to local streams, which, he said, pollutes the water bodies. Most of the streams in Thimphu, he said, are highly contaminated with faecal coliforms. “But the residents also have no choice than to pipe their wastewater into the streams.”

Johkasou tanks, he thinks, will resolve these issues. 

The wastewater that comes into the tank will go through a filtration process and be cleaned using chemicals like chlorine. Once the water is cleansed, it can be released into the streams without polluting the water bodies.

According to Passang Tshering, the technology provides a decentralised approach to wastewater management, permitting households and communities to independently manage their wastewater. They do not have to rely on expensive and extensive central systems. 

“I hope the tanks can play a key role in encouraging people to be more responsible for their own waste,” he said, adding that BTO has to now gear towards advocating about the new technology, availability of the technology in the market, and the affordability of the tanks.

To achieve that, BTO has to collaborate with the government. The government, he says, can ensure that the tanks can be provided to people at a  subsidised rate. 

The Johkasou Tanks can be used in other dzongkhags where a central sewer system is not available. 

With technical support from JOYLET Japan, the tanks have been installed in Thimphu Thromde’s worker camp in upper Mothithang.