Environmental Protection Agency (EPA) Model Lead Based Paint Risk Assessor Practice Test

When conducting soil sampling, what is the primary purpose of obtaining multiple subsamples?

1. To increase the overall weight of the samples

2. To average out variations in contamination levels

3. To ensure compliance with local laws

4. To speed up the sampling process

The correct answer is: To average out variations in contamination levels

The primary purpose of obtaining multiple subsamples during soil sampling is to average out variations in contamination levels. Soil contamination can be quite heterogeneous, meaning that levels of contaminants can fluctuate significantly over small areas due to various factors such as proximity to contamination sources, soil composition, and historical land use. By collecting multiple subsamples from different locations within the sampling area, a more accurate representation of the overall contamination level can be achieved. This averaging helps identify potential health risks more reliably and allows for better risk assessment and decision-making based on the overall conditions of the site. The other options do not accurately reflect the main objective of taking multiple subsamples. Increasing the weight of the samples does not add value to the assessment of contamination levels. Compliance with local laws is important but is not the direct reason for taking multiple samples, and speeding up the process is not a priority when ensuring the accuracy and reliability of the sampling results.