Thousands of lives have been saved in Africa thanks to an ancient Chinese water pump design and the innovation of a former Birstall teacher.

When he was 18, Ian Thorpe took a gap year and taught science and maths at a rural school in Zimbabwe. Two of his young pupils died through drinking contaminated water after a snake fell into a well, decomposed and contaminated the supply. The nearest water supply, which was also open to animals, was two miles away.

Mr Thorpe felt this tragedy could have been prevented and, on returning home, undertook a degree course in ecology and land and water resource development.

"There was a fundamental need for clean water and I looked at ways that a system could be maintainable," he said. "I went back to Zimbabwe and supervised an organisation called Project Trust, run by British volunteers who set up useful projects in rural areas, one of which was trying to find a simple way of lifting water from the ground."

Many water pumps had been introduced into Africa but required skilled mechanics or expensive parts to repair them. Along with two Zimbabwean teachers, 36-year-old Mr Thorpe discovered a 2,000 year-old principle used in ancient China using bamboo pipes and rope, called an elephant pump.

The pump is fully enclosed, pulls up a litre of water each second and is made using local materials - costing £200 in total. A pilot scheme of 100 pumps was launched and the National Lottery gave the now-formed charity Pump Aid a £75,000 matched-grant to build 400 pumps over a two-year period. It built 514 pumps and has now built more than 900. The quality of water from the pump exceeds World Health Organisation guidelines and one pump can provide clean water for 600 people in a village.

At a world summit for sustainable development last year, Pump Aid was chosen as the best new project and the charity received inquiries from 21 African countries. Work has now begun in Mozambique and Malawi.

"When we provide people with access to clean water, we also give them an income," said Mr Thorpe, of Bradford Road in Birstall. "I went back recently and saw schools growing their own vegetables. Each child grows vegetables to take home.

"It also gets families off the poverty line. If there is a break in the rainy season and the crops do not get the water they need, water from the pump can be used to sustain the crops during that time and can mean a good harvest is not ruined. Helping build and maintain the pump themselves gives the local people a sense of ownership."

Next month the charity is launching a campaign called 'Water's Cool in Schools,' which will link up with schools in Zimbabwe, Mozambique and Malawi. A British school that raises £200 will get a photo of their pump in Africa and letters from the children and staff.

A new resource pack is also being developed to show schools how to take National Curriculum lessons around the water issues in Africa.

As part of the campaign, watercooler supplier AquAid has pledged to send £20 to Pump Aid for each school which has its watercoolers who contact them.

Mr Thorpe, the executive director of Pump Aid, can be contacted on (01924) 470326 or at www.pumpaid.org