In the rapidly growing landscape of small and medium towns around India, where space, energy, and maintenance capacities are often constrained, innovation must address simplicity in conceiving solutions at decentralized scales.

It is within this context that Hashtag PerCapita was commissioned to provide technical support (between December 2024 and March 2025) for engineering design and provide implementation support to build a 20 KLD Humus Bioreactor system for a cluster of 58 households in Kandavara Colony, Chikkaballapur, Karnataka.

This is the same breakthrough solution that won the 4th SanTech Hackthon held in 2024 (and organized by FINISH Mondial ). This assignment was contracted to Hashtag PerCapita by Technology Informatics Design Endeavour (TIDE) , which is the program implementing agency supported by BORDA South Asia and the Federal Ministry for Economic Cooperation and Development (BMZ) . The overall team ensured a technically sound, ecologically sensitive, and socially inclusive process through the course of the implementation.

At the heart of this intervention lies the Humus Bioreactor, a fixed media based hybrid Nature-based Solution (NbS) that integrates self-regulating biofilm attached growth process, and 🔗IoT-enabled remote monitoring to achieve near-zero energy use and no secondary sludge generation.

Designed as a plug-and-play, rapidly deployable module, the Humus Bioreactor bridges the gap between sophisticated engineering and low-cost adaptability. It operates entirely on natural draft aeration, eliminating mechanical blowers, and integrates IoT-enabled remote monitoring and UV disinfection, ensuring compliance with environmental and regulatory standards♻️.

The system consumes less than 0.2 kWh per kilo-liter per day, and requires minimal maintenance, making it one of the most energy-efficient and community-manageable treatment systems in its class.

The project showcases innovation in design, digital integration, and engineering to conceptualize nature based solutions which are not just a proof of concept, but serves as a replication-ready model for India’s emerging urban peripheries due to its affordability and adaptable scale for diverse settlement clusters.

Note: The case story is summarised as a video which is attached with this post.