Pilot Faecal Sludge Treatment Plant – Devanahalli
The town of Devanahalli, situated at a distance of 39 km from the city of Bangalore, located ~10 kms from Bangalore International Airport,
Devanahalli comprises of 6,400 households, which are spread across its 23 wards. Thanks to its proximity to the airport, Devanahalli is
witnessing a burgeoning of commercial and residential establishments. Like most developing towns, its sanitation infrastructure is
unable to keep pace with its growth. This has led to environmental pollution, which has implications on human health. It is expected
that this small town will be growing significantly considering the existing and planned developments programmes around the town.
Presently Devanahalli TMC does not have underground drainage (UGD) system, therefore most of the households dependent on pits or septic tanks for disposal of sewage from toilets. The TMC owned desludging truck, with the storage capacity of 4,000 litres, transported the sludge collected from households to nearby farms, where it was directly applied directly onto soil or dumped at remote locations.
A number of treatment methodologies ranging from mechanical treatment systems like LaDePa (a fecal sludge pelletisation process) to non-mechanical treatment systems like sludge drying bed (planted and unplanted) were explored for their suitability for Devanahalli. Though mechanical treatment systems are known to be efficient in treating faecal sludge, they turned out to be economically unsuitable for Devanahalli owing to the high energy requirement to operate them. Non-mechanical plants, on the other hand, such as drying beds require low energy;though they require a larger space and may encounter frequent clogging issues. Based on these learnings, a combined approach of DEWATS principle, solid-liquid separation, anaerobic digestion, dewatering and pathogen removal was adopted. . In order to ensure the optimum usage of the treatment facility and also to inform the residents about the FSTP, various awareness programmes like street play, pamphlets distributions, meeting with different stakeholders are carried out.