How many soil sub-samples should be collected for one composite soil sample?

Collecting a composite soil sample involves taking multiple individual soil cores, which are then combined to provide a representative analysis of a larger area. The correct number of sub-samples for one composite soil sample typically ranges from 3 to 10 cores. This range strikes a balance between obtaining enough data to accurately reflect the lead levels and ensuring that the process remains manageable and efficient.

Using 3 to 10 soil cores allows assessors to capture variability within the sampling area, which is crucial for an accurate representation of lead contamination in the soil. Collecting fewer than three cores might not provide a sufficient assessment of the area, potentially overlooking areas of higher contamination. Conversely, exceeding 10 cores may lead to redundancy without significant additional benefit, making it less practical for risk assessment purposes.

This best practice aligns with established methodologies in environmental assessments, ensuring that the collected sample can provide valid and reliable data for evaluating lead contamination risks.