What is typically required after the first sample when conducting lead water testing?

When conducting lead water testing, sampling hot water after the initial cold water sample is crucial for a comprehensive assessment of lead levels. Hot water can leach lead from plumbing materials, especially from older pipes, fittings, and solder that might contain lead. This means that the lead concentration can be significantly different between cold and hot water samples, providing a more complete picture of lead contamination risk in a household's water supply.

Collecting a hot water sample allows inspectors to gauge the impact of temperature on lead leaching and to understand the potential exposure risks that may arise from using hot water for cooking, drinking, or bathing. Given that various plumbing systems may interact differently with hot water, it is essential to include this step in the testing protocol for accurate risk assessment.