Null-Space Monte Carlo Particle Backtracking to Identify Groundwater Tetrachloroethylene Sources

Stochastic Particle Tracking Application in Different Urban Areas in Central Europe: The Milano (IT) and Jaworzno (PL) Case Study to Secure the Drinking Water Resources

“…The case study discussed in this paper focuses only on the aquifers A and B, which are separated by a clay layer in the south part of the domain (the aquitard is represented by a brown line in (Figure 3), that becomes discontinuous and then disappears northward. Based on the previous studies [18,26], the hydrogeological conceptual model has been updated with the most recent stratigraphic data retrieved from local authorities (Environmental Protection Agency (ARPA) and Lombardy Region).…”

“…The groundwater flow model used in this paper comes from previous works [18,26], however some essential details are reported in the Supplemental Material (Table S3). Although the NSMC method was already presented, the main aim herein is to identify the main receptors (i.e., public wells) starting from several sources formerly identified by the use of cluster analyses [7,39].…”

“…The model was previously implemented by reconstructing the layer characteristics (thicknesses and hydraulic properties) and the low-permeability lens extensions using many stratigraphic logs available for the area [18,26]. The first model layer has an average thickness of 30 m and represents the shallow aquifer (Aquifer A), the most impacted by contamination nearby the suspected sources.…”

“…Once the model was built and calibrated, the NSMC analysis has been applied following the procedure widely presented and discussed in the literature [17,18,31]. A Flow diagram is presented as Supplementary Material (Figure S1).…”

“…In the first case, a Null-Space Monte Carlo (NSMC) coupled with forward particle tracking (PT) method was chosen. Differently from previous works that were focused on a backward particle tracking analysis to search the potential sources [4,[16][17][18], here the forward tracking is used to find the sensible receptors that are probably impacted by the contamination (i.e., water supply wells). In the second case, a classical Monte Carlo (MC) coupled with PT was preferred, due to the most complex hydrogeological conditions and the lack of data availability.…”