Could cows help solve the world’s sewage problem?

Untreated sewage leads to poor sanitation and disease around the world. Its effects are felt strongly in India, and Bangalore resident Tharun Kumar turned to cows for a solution.

With help from the Biomimicry Institute, he has designed and built 50 sustainable sewage plants that work in a similar way to a cow’s stomach. The system has no moving parts, so doesn't require any power or people to operate it.

Voice: Patrick Aryee
Digital producer: Jennifer Green
Animator: Jules Bartl
With thanks to Tharun Kumar, ECOSTP and Dr Dai Grove-White, University of Liverpool

(Image: Cow, Credit: BBC/Jules Bartl)