The system has been tried, tested and evaluated
in the field since February 1993. The evaluation period extended over five
years and involved scientific, health and environmental impact studies, as
well as community feedback. Over 9 000 units have been installed
on a widespread basis throughout South Africa, neighbouring countries, namely
Botswana, Namibia, Mozambique, Zambia, Zimbabwe and in countries further afield,
such as Ghana, Uganda, India, Israel, Greece, Cyprus, Brazil, New Mexico-USA
and Australia.