Contaminant Fate and Reactive Transport in Groundwater - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 852

including a simplified reactive transport scenario modeling and a field study are
illustrated. These applications are focused on the investigation of the fate and
transport of two kinds of contaminants frequently found at contaminated sites:
monoaromatic petroleum hydrocarbons (BTEX) and ammonium (NH 4 + ).
19.2 Basic Theory on Contaminant Transport
The first step when dealing with contaminated groundwater is the definition of
a conceptual model on flow and contaminant transport at a specific site. Many
pieces of information need to be integrated in the conceptual model including the
knowledge of the physical configuration of the aquifer (i.e. geometry, areal extent,
depth of groundwater table, thickness and geological characteristics of the dif-
ferent formations, hydraulic boundary conditions), hydraulic properties (i.e.flow
direction, hydraulic gradient, permeabilities, storage coefficients, recharge rates),
transport properties (i.e. dispersion coefficients, effective porosity), geochemistry of
the background groundwater and interaction with the solid matrix, physico-chemical
properties of the contaminants (i.e. density, solubility, partition coefficients, vapor
pressure), information about the contaminant release scenario (i.e. suspected source
location, mass and duration of the leakage) and about potential targets (i.e. human
and/or ecological receptors). The development of the conceptual model should lead
to a hypothesis on the interaction of sources, migration pathways and receptors.
Figure 19.1 shows a sketch of a conceptual representation of contaminant release
and migration in a shallow unconfined aquifer underlying an industrial site.
Fig. 19.1 Schematic representation of groundwater contamination and impact on sensitive
receptors