CDPH Lead Inspector/Assessor California State Practice Exam

Which type of water is more likely to corrode lead: soft or hard water?

1. Soft water

2. Hard water

3. Both equally

4. None

The correct answer is: Soft water

Soft water is more likely to corrode lead because it generally has a lower mineral content and a higher acidity level. These characteristics make soft water more aggressive in nature, meaning it can dissolve certain metals, including lead, more readily than hard water. Hard water, on the other hand, contains higher concentrations of minerals such as calcium and magnesium, which can act as a protective barrier on plumbing surfaces. This layer can help inhibit lead leaching into the water. Therefore, when assessing the risks associated with lead contamination in drinking water, it's important to consider the type of water. Soft water, due to its corrosive properties, poses a greater risk for lead exposure. Understanding the relationship between water chemistry and lead corrosion is essential for lead inspectors and assessors in evaluating potential sources of lead contamination in buildings and infrastructure.