The present invention is a method for treating contaminated water streams resulting from the production of coal-bed-methane. The method of treating contaminated water streams typically includes the steps of: providing a reaction vessel that contains a bed of weak acid cation ion exchange resin beads; introducing the contaminated water stream to the reaction vessel; allowing for the exchange of hydrogen ions for sodium ions; removing the ion exchanged treated water from the reaction vessel; stopping the stream of contaminated water; and regenerating the weak cation exchange resin.