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

When soil conditions inhibit the collection of soil samples, using a mathematical rate of contamination reduction provides a scientifically sound approach to estimating the potential contamination levels. This method relies on established mathematical models and historical data, enabling practitioners to make informed predictions about the extent of contamination based on previous observations of how contaminants behave in similar environments.

Mathematical models often incorporate factors such as degradation rates, the spread of contaminants over time, and remediation efforts already in place. As a result, this approach can yield estimates that are reliable and can guide decision-making in the absence of physical samples.

While the other methods have their merits, they may not provide the same rigor and reliability. For example, a visual assessment can offer preliminary insights but lacks the quantitative basis needed for accurate estimation. Similarly, assessing site-wide contamination measures or contamination sources may inform the situation but does not directly substitute for a numeric estimate of the rate at which contamination decreases over time. Thus, using the mathematical rate of contamination reduction stands out as the most effective approach under these specific conditions.