CDPH Lead Inspector/Assessor California State Practice Exam

Which component is primarily responsible for the lead hazard in drinking water?

1. Pipes built before 1975

2. Plastic water bottles

3. Corrosion of household plumbing materials

4. Contaminated municipal water sources

The correct answer is: Corrosion of household plumbing materials

The primary component responsible for lead hazards in drinking water is the corrosion of household plumbing materials. Over time, pipes and fixtures made of lead or with lead solder can corrode, especially when the water has low mineral content or is acidic. This corrosion releases lead particles into the drinking water supply. While pipes built before 1975 are often associated with lead hazards due to historical plumbing practices, it is the corrosion processes that facilitate the actual leaching of lead into the water. This means that even newer plumbing can potentially cause lead contamination if lead-containing materials are present and susceptible to corrosion. Plastic water bottles do not typically contain lead and are not a source of lead hazards in drinking water. Additionally, contaminated municipal water sources may pose a risk, but lead specifically arises mainly from the internal plumbing rather than the source water itself. Thus, focusing on the corrosion of household plumbing materials gives a clearer understanding of how lead enters drinking water systems.