What is the required sampling frequency for soil when less than 1,000 square feet?

In the context of soil sampling for heating oil tank investigations, guidelines typically recommend a sampling frequency that is proportionate to the area being assessed. When the site in question covers less than 1,000 square feet, the requirement to take two samples is based on the need to adequately represent the variability within the soil.

Taking only one sample may not capture this variability, leading to a skewed assessment of contamination levels. The rationale for two samples is to provide a more robust understanding of the site conditions and to account for any potential differences in soil characteristics or contamination levels that may exist within the sampled area. This ensures that monitoring and remediation efforts, if needed, are based on a clearer and more comprehensive analysis of the site.

This approach is rooted in best practices for environmental assessments and regulatory compliance, helping to ensure that decisions regarding remediation and health risk evaluations are informed by sound scientific data.