The tendency of a water to corrode pipes and fittings is health related as well as being of economic importance, since the materials released into water by corrosion may include lead, cadmium, and other toxic metals. The Corrosivity of water is not easily measured. However, equations have been developed that reasonably predict the tendency of water to corrode on the basis of temperature, total dissolved solids, calcium content, hardness, pH, and alkalinity. These equations indicate the calcium carbonate stability of water  the tendency to either deposit or dissolve calcium carbonate (CaCO3), the most common scale forming compound. In most cases, a water that is neutral or slightly scale forming is preferred.

Water that is excessively corrosive can be stabilized  made noncorrosive  by the addition of lime and soda ash to increase the pH and alkalinity, or by the addition of polyphosphates or silicates to form protective coatings on the pipe walls. These treatment processes are relatively complex, requiring trailed operators and regular monitoring.