If soil conditions prevent receiving soil samples, what estimate may be used?

In situations where soil conditions inhibit the ability to collect physical samples, utilizing a mathematical rate of contamination reduction can be an effective alternative. This methodology involves analyzing historical data and trends related to contamination levels, allowing for an estimation of the degree to which contaminants may have been reduced over time due to natural attenuation processes.

By applying factors such as degradation rates, environmental conditions, and previous contamination assessments, one can estimate the current state of contamination without the need for direct soil sampling. This approach relies on established scientific principles and known behaviors of contaminants in soil, which can yield useful information for decision-making and remediation strategies.

The other options do not provide a systematic or quantifiable method for assessing contamination under such conditions. Visual assessments might overlook underlying issues or provide subjective interpretations, while site-wide contamination measures do not offer localized insights. Contamination source assessments may identify potential sources, but without specific data on current soil conditions or contamination levels, they cannot provide a reliable estimate.