A process using a regenerable inorganic media capable of removing contaminants by catalytic oxidation or reduction, as well as heavy metal adsorption, from well and surface water sources. The specific material is specially-treated gamma-type electrolytic manganese dioxide, the treatment involving comminuting to a 20-60 mesh size, complete neutralization and washing to remove fines, residual acidity and neutralization products. Certain taste, odor and staining water contaminants such as hydrogen sulfide, iron and manganese can be oxidized and filtered by the media with subsequent removal from the system by simply backwashing with water or water in combination with simple chemicals. Heavy metals are removed by a different adsorption mechanism on the same media followed by regeneration with a dilute acid. Pretreatment of the media with sodium hydrosulfite further allows the removal of residual chlorine. This product demonstrates a high degree of selectivity and a high capacity for all three types of contaminants. The results of the treatment of water solutions containing a wide variety of contaminants are given showing that most of the contaminants are readily removed to levels established by the U.S. Environmental Protection Agency for drinking water. The inorganic catalytic oxidizing/reducing and adsorbent material can be placed in larger canisters for point of entry use or in smaller cartridges for point of use applications, depending upon the particular requirement.