NATURAL INSTINCTS

Without any electricity or harmful chemicals, ECOSTP Technologies has processed billions of litres of sewage since 2017 

- AJAY SUKUMARAN

A decade ago, when his gated villa community in Bengaluru's Whitefield locality was grappling with a clogged drain, Tharun Kumar, 54, an IT security specialist, began looking for ways to set up a zero-maintenance sewage treatment method that could provide good-quality recycled water. The main concern, he says, was to prevent wastewater from draining into the nearby, much-polluted Varthur lake.

Inspiration came from nature itself-specifically, the stomach of the cow, which breaks down digestive matter through powerful anaerobic bacteria. The stomachs of ruminants comprise four chambers. Replicating this, Kumar and his team designed a septic tank with four stages.