Aggressive carbon dioxide causes corrosion on concrete, pipe systems, and hot water storages in black steel. The corrosion products make the water indistinct and colours it red with corrosion and ochre.
The carbon dioxide is often present in raw water in areas with decalcified stratums of earth. The lack of calcium means that there is no neutralization of the carbon dioxide.
Aggressive carbon dioxide can be neutralized in a pressure filter plant by means of a calcium based filter material called Magno-Dol. In special cases, aggressive carbon dioxide can be degassed by heavy aeration.