CDPH Lead Inspector/Assessor California State Practice Exam

Soil Composite sampling should consist of at least how many sub-samples?

1. 3

2. 5

3. 7

4. 10

The correct answer is: 5

Soil composite sampling is a crucial method used to assess lead concentrations in soils, particularly in areas where lead contamination is suspected. The recommended standard for composite sampling typically requires a minimum of five sub-samples to ensure that the sample is representative of the entire area being tested. Using a minimum of five sub-samples helps to account for variability in soil composition and contamination across a given site. By combining multiple samples, the analysis becomes more representative and reduces the likelihood of skewed results that could arise from taking a single sample from a potentially non-representative location. The goal is to create a composite that reflects the average lead concentration over the area, allowing for a more accurate risk assessment. In comparison to other options, fewer sub-samples may not provide a sufficient representation of contamination levels, potentially leading to incomplete or inaccurate assessments. Therefore, the choice of five sub-samples is aligned with standard practices in environmental assessments and helps ensure that the data collected is reliable and valid.