An 18-year-old girl from Delhi has built a low-cost greywater recycling system that helps save up to 6,000 litres of water monthly. The woman, Mannat Kaur, created a model that uses a Scupper Valve to collect water from drains and a three-bucket filter that purifies it using charcoal, orange peel and pebbles. "No plumbing changes are needed," Mannat said.