CDPH Lead Inspector/Assessor California State Practice Exam 2025 - Free Lead Inspector Practice Questions and Study Guide

To collect a second draw water sample accurately, it's essential to represent the water's quality after a certain amount of time has passed since the last sample was taken. Allowing the water to run for 15 minutes is a standard procedure designed to ensure that the water being tested isn't stagnant and has had sufficient time to clear any sediments or contaminants in the plumbing system.

The extended run time allows for the sample to better reflect the lead concentration from the source rather than from any deposits in the pipes. This helps ensure that the result is more indicative of regular water usage conditions in a household or building, making it a reliable measure for assessing potential lead contamination levels.

In this context, other options suggest varying run times that are either shorter or longer than the recommended duration, which could result in collecting a sample that does not accurately reflect the conditions typically encountered during daily use.