Which factor contributes to water's corrosiveness?

The presence of free chlorine in water can significantly contribute to its corrosiveness. Chlorine is commonly used in water treatment to control pathogens, but it can also react with metal surfaces in pipes and fixtures, leading to corrosion. When chlorine is present in its free form, it can oxidize metals, particularly those that are more reactive, such as iron and copper. This oxidation process can create conditions that lead to increased metal ion release into the water, ultimately causing degradation of plumbing systems and fixtures over time.

In contrast, while high pH, low dissolved oxygen, and high mineral content can influence the overall chemistry of water, they are not primary factors in the corrosive nature of water in the same way that free chlorine is. For instance, high pH can sometimes lead to scaling rather than corrosion, and low dissolved oxygen levels usually equate to less aggressive water chemistry. High mineral content can change the water's hardness but does not inherently lead to increased corrosiveness as seen with free chlorine. This distinction is key in water quality assessments and managing the integrity of water distribution systems.