How Do I Calculate Contaminant Mass or Volume with Only 2D Data?

In many cases, there is only one measurement at each location. Therefore, estimates of contaminant mass or the volume with concentrations exceeding some value will need to be made using a presumed contaminant thickness. EnviroInsite provides a means of estimating the area in each 2D contour interval.

Click Plot> 2D Data from the main menu and select Contours. On the Options tab, place a check in the Estimate Area box. The results (contour interval, average value, area) are written out to the Data tab in the Work Log window. Copy and paste the final result from the Data tab to Excel and setup the calculations in Excel for some assumed finite contaminated thickness. The mass associated with each interval is the product of the average value, the area, and the thickness. If this is a dissolved constituent, then you also need to multiply by the porosity. You may also want to account for an adsorbed phase by multiplying by the retardation factor. If there are multiple concentration measurements at different elevations, then you may want to select Check for Points at Same Location and select the Maximum value.