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Various techniques might be adopted to lessen the concentration of Se in drinking water. The commonly applied techniques are ion exchange, activated alumina (AA), reverse osmosis (RO), and distillation. Ion (anion) exchange can decrease selenium by 90–95%, as selenate ion is highly favoured. Though oxidation of Se (IV) is more problematic, it can be done easily with the help of free chlorine. Se (IV) can be transformed to Se (VI) within five minutes by maintaining the concentration of free chlorine to 2 mg/L. The pH between 6.5 and 8 is observed to be an ideal rate of oxidation. Removal rates for other methods used for selenium elimination are distillation (>98% removal), activated alumina (85–95% removal), and reverse osmosis (RO) (>90% removal) (CGWB 2014).