Community-scale drinking water treatment systems have
also been implemented. These may include communityscale
filtration or disinfection plants that provide safe
drinking water from existing sources. One example is the
Water Health International model, where water is filtered and
disinfected using ultraviolet technology. This water is then
sold to residents or businesses for use in drinking and use
commercial operations. In some cases, communities make
a down payment to get a Water Health Center installed, and
then pay ongoing service charges for the water used. Their
average Center is designed to provide a community of 3,000
residents with up to 20 liters of drinking water per person per
day. Water Health International is expanding the system of
decentralized water purification to 600 communities in India
through a US$ 15 million IFC-financed project. Other projects
are underway in Mexico, the Philippines, and Sri Lanka.
Community-scale interventions for pure drinking water
are also used in emergency situations and in transition
scenarios. In Iraq, UNEP-IETC provided drinking water from
saline marsh water through packed low-pressure reverse
osmosis units that were provided to six communities in
pilot projects. Other approaches were tested including PVaugmented
power for water distribution at a community level
and the pilot testing of solar stills (UNEP 2009).