GSI Mann Kendall Toolkit

GSI Mann-Kendall Toolkit

Simple tool for performing concentration trend analysis

The GSI Mann-Kendall Toolkit is a free, simple, easy-to-use software tool to help environmental professionals efficiently conduct concentration trend analyses for any groundwater constituent.  Programmed in the Microsoft Excel spreadsheet environment, the software employs the same Mann-Kendall plume stability methodology that was previously developed for the MAROS software (Aziz et al., 2003; AFCEE, 2004).  This software tool can be used to demonstrate the plume stability condition (expanding, stable, or decreasing) and track the progress of remediation efforts, in a quantitative and consistent manner for consideration by both site managers and regulatory personnel.

Analysis of the trend of constituent concentrations in affected groundwater plumes has many applications in groundwater plume management and remediation.  Regulatory programs typically require demonstrating that groundwater plumes are stable or controlled to confirm protective conditions.  Monitored Natural Attenuation (MNA) is increasingly being used as a remedy for cleanup actions at sites with affected soils and/or groundwater.  A primary line of evidence supporting MNA as a remedy is demonstration of a stable or shrinking plume condition, based upon historical monitoring data (ASTM 2004; USEPA 1999).  Evidence for the discontinuation of extraction-based remedies often includes demonstration of stable or shrinking plumes after shut-down of extraction systems.  Formal evaluation of plume stability can be accomplished using a variety of statistical methods, of which the Mann-Kendall protocol is one of the most commonly used and widely applicable tools.