Water Engineering and Development Centre
Author(s): HPCIDBCPublisher: High Powered Committee for Integrated Development of the Bagmati Civilization
In the Kathmandu Valley, around 70% of the households dispose their excreta directly into the sewer line while remaining 30% of the households still depend on onsite systems such as pit latrines and septic tanks.
The practice of using onsite system is found to be more environmentally friendly in the present context of Kathmandu compared to direct discharge of wastewater into the sewer lines. Currently, due to lack of adequate wastewater treatment facilities, more than 95% of the sewerage ends up into the rivers without any form of treatment. Disposal of untreated sewerage and haphazard dumping of solid waste are seen as the two major contributors of river pollution in the Valley, evident from the deteriorating water quality of River Bagmati and its tributaries.
Onsite sanitation systems are prevalent mostly in the outskirts or peri-urban areas of the Valley. The study shows that 30% of households in urban areas of Lalitpur, 8% in Bhaktapur and 18% in Kathmandu District still use septic tanks for disposal of excreta while in the peri-urban areas more than 50% of the households use suchonsite systems. There are around 68,000 septic tanks in the Valley. These onsite systems need regular emptying due to accumulation of faecal sludge (FS). Sludge emptying is done either mechanically or manually. Currently, a group of entrepreneurs provide mechanical FS cleaning services while many individuals are associated with manual pit emptying. On average a household empties a septic tank at an interval of 3 to 3.5 years. However, due to the absence of a proper faecal sludge management (FSM) system almost all the collected sludge is directly discharged into rivers. Thus, there is an urgent need for a proper FSM system in the Valley.
Establishing a FS treatment system under a responsible institution/authority is seen as the foremost and integral component as other essential amenities for FSM i.e. sludge collection and transportation are already in place. The entire FSM system could be operated through a public private partnership approach as there is an enormous potential of benefiting multiple stakeholders in this process. Establishment of a FSM system in Kathmandu will bea good demonstration for other urban or peri-urban areas in the country which faces similar sanitation problems.
Faecal sludge | Nepal | Septic tank systems | sewage | www