The fluoride concentration in ground water is increasing at an alarming rate. Poor ground water recharge, excessive consumption of water and other geological factors contribute to this effect. Conventional reverse osmosis (RO) membrane system has failed because fluoride concentration in permeate is not consistently below 1 mg/L. Moreover, the reject stream of the RO process containing higher fluoride concentration is left untreated. A treatment method has been devised with an objective to reduce fluoride concentration to less than 1 mg/L from fluoride contaminated water using calcium carbonate pretreatment and reverse osmosis. Also a passive adsorption system to treat the reject stream of membrane process has been developed wherein the fluoride concentration in the final effluent is below ambient concentration. This combined system can be used to treat fluoride contaminated water without generating secondary wastes.