## Estimating Quantities

The general topics of Estimating Average Concentrations, and Plume Change/Attenuation Over Time are related to Estimating Quantities (see General Topics, Table 2). Interpolated grids of contaminant concentrations created using simple geospatial methods can be used to quantify metrics such as average concentration, total mass, or volume of media above cleanup goals. Performing interpolations and calculating these metrics for sequential sampling events can be used to evaluate plume change over time (for example, shrinkage) visually or statistically by performing trend analysis on the metric in question.

**Understanding the Results** ▼*Read more*