Environmental Engineering Reference
In-Depth Information
• Successful remediation is possible using a simple and established method (exca-
vation) for soil, accompanied by capping, deed restrictions, institutional controls,
and pumping of free product.
• After effective remediation and scientifically informed planning, heavily contam-
inated sites can eventually turn into productive land uses.
14.8 Summary and Conclusion
This chapter presented several case studies designed to illustrate some of the principles
that can form the scientific and scientifically informed planning foundations to attain sus-
tainable urban watersheds. These principles include
• A detailed urban geological map is required to comprehensively assess a dam-
aged site and facilitate efforts for its remediation and redevelopment.
• Geology in urban settings is dominated by unconsolidated sedimentary deposits,
and these deposits are complex.
• Major urban areas are located near large surface water bodies, and the hydrologic
and hydraulic connections between them often dictates the extent and severity of
the contamination.
• Common contaminants exist at many large urban industrial sites, and they have
similar storage methods outdoors, and common indoor or near-building release
points (e.g., sumps, tanks, trenches, floor drains, and pits). This knowledge can
assist source control efforts.
• Contaminant migration is closely related to the risk factors for soil and groundwa-
ter. Immobile contaminants released into vulnerable geologic environments may
not create a synergistic effect because they have high soil risk factors and therefore
do not reach groundwater. Mobile contaminants with low soil risk factors tend to
exhibit high groundwater risk factors; they will migrate in vulnerable geologic
environments and create a synergistic effect.
• Anthropogenic influences, e.g., sewer systems, can change the migration path-
ways for contaminants. A rigorous site investigation is required to determine if
the anthropogenic affects will impede contamination or enhance it.
• Urban investigation and geologic forensic techniques are useful and necessary
components of most, if not all, site investigations. Three-dimensional maps com-
municate information clearly and effectively.
• Remedial technologies vary and must be matched to the remediation effort based
on the specific characteristics of the site. One size does not fit all here.
• The cost of environmental cleanup varies proportionately with synergistic effects
and is often increased by the presence of shallow groundwater.
• Redevelopment alternatives must rely on the science used for remediation to guide
the proper selection of land uses.
Many of these concepts are dramatically apparent when comparing and contrasting the
case studies. The following are just a few important examples:
 
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