Treatment of un-wetted or low moisture activated carbon with a suitable quantity of carbon dioxide provides a material which, on contact with water, controls pH in treatment water. Use of this treated activated carbon in a water treatment system provides water having an essentially neutral pH which is immediately potable thereby eliminating the necessity to drain and dispose of any soak water. The contact pH of the treated carbon remains within the potable pH range for treatment of more than 100 bed volumes. Additionally, the modified carbon may minimize metal leaching from contaminants in the water.