CDPH Lead Inspector/Assessor California State Practice Exam

Which type of water is more likely to leach lead into the water supply?

1. Cold water

2. Hot water

3. Mineral water

4. Distilled water

The correct answer is: Hot water

Hot water is more likely to leach lead into the water supply due to the increased solubility of lead at elevated temperatures. When water is heated, the molecular activity increases, allowing for greater interaction between the water and any lead-containing plumbing materials, such as pipes and fixtures. This interaction can cause lead to dissolve more readily into the water, particularly if those materials are aged or corroded. In contrast, cold water typically has a lower capacity to leach metals compared to hot water, as the cooler temperatures tend to reduce the solubility of lead. Mineral water and distilled water have distinct characteristics; mineral water is generally sourced from natural springs and contains varying mineral content that doesn't typically contribute to lead leaching. Distilled water, being purified and virtually free from contaminants, is also less likely to leach lead. Thus, hot water stands out as the primary concern for potential lead contamination in drinking water supplies.