During data analysis the user has the option to ignore the presence of NAPL when fitting the spatiotemporal model, or substitute detections of NAPL with site maximum solute concentrations. NAPL substitution should only be used if it is known that the solutes entered into GWSDAT are derived from dissolution of the NAPL. This functionality was introduced to avoid the situation whereby an area of wells containing NAPL appears as a minimum on concentration contour plots because groundwater solute concentration data is not available.
Note: Any solutes that are not derived from the NAPL can be excluded from the NAPL substitution process by flagging them as “NotInNAPL” or “E-acc” in the historical monitoring data table of the input worksheet. Note also that only one solute data point needs to be flagged to remove that solute from the substitution algorithm.