Groundwater-Related Risk Assessment - Dealing with Contaminated Sites: From Theory Towards Practical Application - page 748

Chapter 17
Groundwater-Related Risk Assessment

Frank A. Swartjes and Juan Grima

Abstract Groundwater includes the pore water in the water-unsaturated upper soil
layer as well as water usually referred to as groundwater, that is, the water in the
water-saturated zone. Groundwater contains contaminants of natural and anthro-
pogenic origin. It is generally recognised by all segments of society that fresh
water is an immensely important resource. From a Risk Assessment point of view,
groundwater needs to be approached from two different perspectives, namely, as
an important protection target and as a means of transport (a pathway) for con-
taminants. For human beings the primary use for groundwater is as a source of
drinking water. Although often underestimated, the water-saturated deeper soil layer
is also a habitat for many organisms. For decades, there has been an on-going
and interesting discussion concerning the intrinsic value of groundwater, some-
times including spiritual and even supernatural or religious arguments. Generally
speaking, the transport of water and contaminants is much faster in the groundwa-
ter zone than in the water-unsaturated upper soil layer. Specific attention will be
given in this chapter to the impact that a revised quantitative groundwater regime,
the presence of heterogeneous soils or aquifers, surface water bodies, anthropogenic
subsurface processes and structures, and heterogeneous soils and aquifers all have
on groundwater quality. Additional attention will be paid to sustainable protection
of groundwater resources, Conceptual Models, mathematical (numerical) models,
Risk Management (including Natural Attenuation and regional approaches), sam-
pling and monitoring, lysimeters and column experiments, the impact of climate
change, mingling groundwater plumes, risk perception and communication, and the
European Water Framework Directive.