The Assessment of Groundwater Vulnerability Due to Leaching of Chemicals: The Review of Attenuation Factor

Abstract

To assess the groundwater vulnerability due to leaching of chemicals, the groundwater system in the unsaturated zone is characterized by conceptual models that are further extended and refined with more detailed mathematical models to understand the governing physical processes in detail. However, due to lack of data and uncertainty level, an intermediate transition through index based models is researched. The attenuation factor (AF) approach, which works under the assumption that the chemicals degrade following a first-order kinetics and determines the fraction of the chemicals that goes to groundwater table, is one of the index based models that has been widely used due to its simplicity. Therefore, the objective of this paper is to review the research works done using the AF approach, to outline the future research needs. Furthermore, the mathematical implementation of the AF approach and the associated uncertainty levels is explained through an example and MATLAB source code.

Mobility in the context of exposure‐based assessment of chemicals for drinking water resource protection

“…These interactions become increasingly significant as the OC content of a soil decreases (Delle Site, 2001; Koskinen & Harper, 1990; Li et al, 2018). Due to degradation and dispersion/diffusion, environmentally relevant concentrations in subsurface soils and aquifers are mostly below the concentrations used in laboratory adsorption studies (Mylevaganam & Ray, 2016; Schulze‐Makuch, 2011). Consequently, the environmentally relevant sorption is often underestimated by these laboratory tests, which are conducted at artificially high chemical concentrations.…”