Environmental Engineering Reference
In-Depth Information
and partitioning of inorganic and organic contaminants was given in Chapter 2 together
with a brief mention of the widely used transport relationship. A detailed treatment of
these subjects can be found in Yong (2001) and Yong et al. (2010).
9.4 Contaminant Transport and Fate
Potential sources of contamination of subsurface water or groundwater (porewater and aqui-
fers) other than inadvertent spills and deliberate dumping of hazardous materials, include
landills, underground storage tanks, waste piles and waste sites, underground injection
wells, unplugged oil and gas wells, various kinds of surface impoundments and settling
ponds, lands treated with pesticides, insecticides, fertilizers, and pipelines transporting car-
bon resources. Figure 9.8 shows many of these potential sources. The types of contaminants,
their concentrations and proportions, and the transport of these in the subsoil and their fate
are critical to the structuring of protective measures necessary for the protection of public
health and the health of the land environment. The need for predictive tools is obvious.
Questions posed by regulators, investigators, containment facility designers, site reme-
diation technologists, and all others working with containment and remediation of site
contamination are summarized as follows:
• Source of contaminants? Nature of contaminant plume?
• Size of contaminant plume? Concentrations and distribution of the various con-
taminants in contaminant plume? Dominant toxic elements and contaminants in
the contaminant plume?
• Where are the receptors? Paths to receptors? Source-pathways-receptors linkage?
• Rate of transport of contaminants? Can we predict its rate and extent of advance?
• Fate and/or persistence of the contaminants in the plume? Can we predict?
• Will contaminant plume threaten or contaminate water resources? Will contami-
nants pose threats to environment and health of biotic receptors?
• Measures for risk management? Risk tolerance?
9.4.1 Analytical and Predictive Tools
Analytical and predictive tools dealing with the fate and transport of contaminants must
account for the following:
• Concentrations of the various target contaminant species
• Hydraulic conductivity of the subsurface material (soil)
• Diffusive capabilities of the target contaminants
• Hydrogeologic setting
• Partitioning potential of the target contaminants
• Solubility of the target contaminants
• Speciation, complexation, and products formed
• Abiotic and biotic reactions and transformations
Search WWH ::
Custom Search