[[Image:defluoridation unit.jpg|thumb|right|250px|Household defluoridation unit (HDU). <br>Photo: ADDIS ABABA UNIVERSITY.]]
[[Image:defluoridator.jpg|thumb|right|250px|The EnDeCo Institutional Defluoridator. It can be made at any desired capacity, normally in the range >20 m3 for a raw water fluroide of 5 mg/L. Photo: [http://www.de-fluoride.net/defluoridation.html De-fluoride.net.]]]
[[Image:contact precipitation unit.jpg|thumb|right|250px| A Contact Precipitation Unit set up as a demonstration plant and run for a couple of years. Since, it has been operating as a simple Bone Char community plant. <br>Photo: [http://www.de-fluoride.net/defluoridation.html De-fluoride.net.]]]
High levels of fluoride in groundwater has been reported parts of in Ethiopia, Malawi, Kenya and Tanzania and can lead to health problems including dental fluorosis, osteosclerosis, thyroid problems, growth retardation and even kidney failure. WHO report shows excessive fluoride intake (3-6 mg/L) can lead to severe and permanent bone and joint deformations of skeletal fluorosis and the consumption of drinking water with even higher fluoride concentrations (10 mg/L) can lead to crippling fluorosis, which causes the hardening and calcifying of the bones.
==Construction, operations and maintenance==
[[Image: Nalgonda technique.jpg|thumb|right|250px|The Nalgonda Technique diagram. <br> Photo: [http://www.de-fluoride.net/defluoridation.html De-fluoride.net.]]]
There are several methods which have been developed to reduce fluoride from contaminated water, such as adsorption, ion exchange, precipitation, electrodialysis and reverse osmosis. These methods have rarely been implemented in developing countries, except in some areas, due to insufficient removal efficiency, unaffordable costs, complicated operation and maintenance, particularly for rural populations.
