Statistics is the science of learning from data and using the results in many industries for various purposes. As environmental consultants, we use statistics primarily to help clients meet regulatory requirements because statistical analyses can provide valuable insights and guidance, potentially saving our clients’ money and time.
Various statistical methods can help streamline assessment and remediation concerning contaminated site cleanup, ultimately facilitating site closure. Statistical analysis can help to answer some important questions that arise throughout the life cycle of a project. The table below summarizes some common statistical questions, statistical methods, and data visualizations (statistical questions modified from ITRC, 2013*).
Statistics is one tool for solving client problems in combination with other methods. However, it is important to note that the output of a statistical analysis is only as good as the input, meaning that the collection of quality field samples and adherence to relevant standard operating procedures are crucial to the quality of statistical analysis.
In conclusion, while statistical analysis is a powerful tool for addressing client environmental issues, its effectiveness depends heavily on the accuracy of data collection and strict adherence to established protocols, ensuring reliable and meaningful results for our clients.
SCS has successfully implemented each of these methods on project sites. Future blogs will describe specific methodologies and processes with actual case studies useful for addressing the following,
Background Studies: after calculating the appropriate background level or establishing a background data set, that level or data set could support the removal of a particular contaminant from further consideration or serve as the remediation objective.
Groundwater trend analysis: to evaluate whether groundwater concentrations are increasing, decreasing, or stable/no trend, which could support the completion of long-term groundwater monitoring. This approach can also help estimate the time to attain cleanup goals.
Spatial Statistics: use several methods to evaluate spatial hot spots and outliers, groundwater plume stability, and groundwater concentration or elevation gradients, which can aid in evaluating areas of high concentrations requiring further evaluation.
*Interstate Technology & Regulatory Council (ITRC) Framework for Developing Quality ITRC Technical and Regulatory Guidance Documents, Revised December 2013
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