The characteristics of drinking water that affect the occurrence and rate of corrosion can be classified as (1) physical, (2) chemical, and (3) biological. In most cases, corrosion is caused or increased by a complex interaction among several factors. Some of the more common characteristics in each group are discussed in this section to familiarize the reader with their potential effects. Controlling corrosion may require changing more than one of these because of their interrelationships.

Essentially no statement regarding corrosion or the general use of a material can be made that does not have an exception (NACE, 1984). The corrosion of metals and alloys in potable water systems depends both upon the environmental factors (solution composition) and the composition of plumbing or fitting material. Concern about the consequences of corrosion varies with the material. Sometimes, it is toxicity from trace metal dissolution and contamination of the drinking water, but for materials such as iron, steel, and mortar linings, the concern is more aesthetic concerns and material degradation. Therefore, this section will address some of the major factors that contribute to corrosion in potable waters, but the reader must refer to literature that comprehensively describes the relationship for the materials of interest.