Reverse osmosis units in groundwater based public water supply system in rural eastern Karnataka, India: an analysis

Adequacy, eco-friendliness and desirability of continuation of reverse osmosis (RO) purification of groundwater for providing safe drinking water to villages in the groundwater resource-deficient eastern Karnataka, India, have been studied in 15 villages in 4 districts of the state, where high fluoride and uranium contamination has been observed. The results indicate that: (i) except in Chitradurga district, there are an inadequate number of RO facilities; (ii) RO water consumption is far less than the minimum amount recommended for drinking by WHO; (iii) while the benchmark of the best performance for RO membranes is >99%, the RO units in use show an ave­rage fluoride and uranium rejection percentage of 92.6 and 95.1 respectively; and (iv) similar to almost all RO units, the installed ones are also wasting water in the water-deficient eastern Karnataka and discharging concentrate with a higher percentage of contaminants into the environment. Better management of RO units and RO concentrate is required.