Kouli_etal_2008_Groundwater modelling_BOOK.pdf - Pantelis ...

In: Groundwater: Modelling, Management… ISBN: 978-1-60456-832-5
Editors: L.F. Konig and J.L. Weiss, pp. 167-186 © 2008 Nova Science Publishers, Inc.
Chapter 6
CONTAMINANTS IN GROUNDWATER
AND THE SUBSURFACE
Z. Yu 1,* , Y. Huang 1 , A. Baron 1 , X. Chen 1 , C. Yang 1 ,
D. Kreamer 1 and M. Johnson 2
1 Department of Geoscience, University of Nevada Las Vegas
Las Vegas, NV 89154
2 Virgin Valley Water District, 500 Riverside Road, Mesquite, NV 89027
Abstract
Remediation of groundwater contamination is becoming increasingly important as
groundwater resources are more extensively relied upon for industrial and drinking water
supplies. Subsurface contaminants can be divided into three general categories: 1) microbial
pathogens, which can be filtered out by some subsurface media and therefore pose the greatest
risk in aquifers with large cracks or conduits, 2) inorganic compounds such as major anions
and cations, metals, and radioactive compounds, whose mobility in groundwater depends on
their interaction with the geologic material, and 3) organic chemicals, including many
pesticides and nonaqueous phase liquids such as petroleum products and solvents. The
movement of contaminants through the subsurface is governed by hydrological, physical,
chemical, biological and transport processes, all of which are explained in detail. Investigation
of groundwater contamination should begin with noninvasive techniques, including review of
historical records, maps and photographs, and some geophysical methods. Contaminant
plumes can then be delineated using soil samples and monitoring wells. Numerical models, as
long as they are developed via a rigorous procedure based on specific questions and available
data, can integrate spatial and temporal variables to more accurately describe the complexity
of subsurface contaminant fate and transport. Various unsaturated and saturated zone models
are described. Remediation in its most basic forms consists of source containment, excavation
of soil in the unsaturated zone, and pump-and-treat methods for water in the saturated zone.
These methods are often impractical, which has led to the ongoing development of
supplemental and alternative methods, described briefly herein.
* E-mail address: zhongbo.yu@unlv.edu. Phone: 702-895-2447.Fax: 702-895-4064. Contact author: Zhongbo Yu,
Department of Geoscience, University of Nevada Las Vegas, 4505 Maryland Parkway, Las Vegas, NV 89154-4010