A small-scale sewerage system called Dojo-Joka system piloted in Hejo will not only manage wastewater but can also be used for recreational purposes.
The sewerage system that would cater to 86 households and more than 700 people in lower Hejo would also prevent secondary pollution such as foul smell, is cheaper and does not take up much space. It does not need major maintenance, would last longer, resist extreme weather conditions, use simple and fewer technologies and can be combined with green spaces.
The treatment plant was constructed last year after the Department of Engineering Services signed a Memorandum of Understanding with Mokan-Joka System (MJS) of Japan and Japan International Cooperation Agency (JICA) in December 2016.
The project has three packages of which two, the detailed survey and constructions of the civil structure are completed. The third package containing laying of pipe network is expected to complete by April or June this year.
JICA is funding the project of about Nu 18 million (M). The plant, with a capacity of 100 cubic meters a day, would have six segregation tanks above which a green space would be created.
Works and human settlement secretary, Phuntsho Wangdi, said the project would directly benefit the efforts of Thimphu thromde in disposing liquid waste in an efficient manner.
He said that with rapid urbanisation and increasing population, urbanisation has become synonymous with increasing waste production. “If the disposal of solid and liquid waste is not taken care of in time, it would create a hazard to health and safety of residents living in crowded cities like Thimphu and Phuentsholing.”
Japan’s minister of economic and development at the embassy in New Delhi, Kenko Sone, said that in the Dojo-Joka system, all wastewater treatment tanks are installed under the topsoil, enabling the land use of the same sewage facility for other purposes such as the development of public spaces as green parks or athletic fields.
During a seminar on small-scale sewage system yesterday in Thimphu, it was emphasised that the Dojo-Joka system provides an alternative wastewater treatment technology using the natural capacity of the soil organism.
President of a non-profit organisation, National Municipal Soil Remediation Liaison Council of Japan, Bunei Saito, said that as the treatment plant does not emit foul smell, it could also be built in the middle of a town. “Sewerage system is necessary infrastructure for better living, to protect the environment and to beautify the place that we live in.”
Technical advisor to the Hejo project, Phub Tenzin, said that the only disadvantage the Dojo-Joka system has is that people cannot use the area frequently as the soil has to be kept porous. “If people are walking frequently on the plants, it will harden the soil. The soil will then stop blocking the smell from beneath.”