An 'intelligent' toilet with an automated flushing system is set to improve urban sanitation in developing countries. Designed by India's Eram Scientific Solutions Private Limited, the 'Delight' public toilet combines advanced GPRS technology for remote surveillance and maintenance, with minimal drain on resources.

The design was awarded a grant of over $450,000 by the Bill and Melinda Gates Foundation earlier this year, as part of the Foundation's second 'Reinvent the Toilet Challenge' – a scheme which aims to encourage the development of next-generation toilets to bring sanitation to the estimated 2.5 billion people who are without. Units are already operational in Delhi, Kerala and Uttar Pradesh, and Eram Scientific plan to roll out a further 10,000 over the coming year.

The unit includes an in-built bio-membrane water recycling facility, and minimises water use by altering the touch-free flush according to the amount of time the user spends in the closet. If they are in there for under three minutes, it uses just 1.5 litres – and no more than 4 litres thereafter. Mud and dust can also be flushed from the closet floor twice a day or daily – according to the amount of 'user traffic' in the area. The toilet is connected to local power and water facilities, but is designed to close automatically if resources are too low. Solar panels can be fitted to reduce its draw on local 230V AC power.

Ria John of Eram Scientific hopes that "a well-connected network of intelligent toilets will bring a paradigm shift in public sanitation".

The 'Delight' toilet also comes with a business plan – based on a combination of customer fees and external advertising space – with an anticipated return on investment of three to five years. There are wider economic benefits, too. Every $1 spent on improved sanitation delivers a $9 return through increased productivity and reduced spend on healthcare, according to the UNDP.

"If we apply creative thinking to everyday challenges, such as dealing with human waste, we can fix some of the world's toughest problems," says Gates Foundation co-chair Bill Gates.

"[This is an] interesting and innovative idea, especially the use of advertising for an extra revenue stream", says Kumi Abeysuriya, a sanitation expert from the Institute for Sustainable Futures at the University of Technology, Sydney. However, Abeysuriya is critical of the design's dependence on existing water supply and sewerage systems. Where these are not already in place, further solutions would be needed to manage sludge and provide clean water for hand washing, which is absolutely crucial for health protection, she says.

This article originally appeared in Green Futures, the magazine of independent sustainability experts Forum for the Future.