Environmental Engineering Reference
In-Depth Information
decline and property dormancy is not just confined to Detroit—it has occurred in many
urban areas around the country.
The sites where industrial or commercial facilities once operated but are now inactive
were named “brownfields” (USEPA 2007). At these locations, expansion or redevelopment
is complicated by real or perceived environmental contamination. There are perhaps over
1,000,000 brownfield sites in the United States alone, with an estimated remediation cost of
several hundred billion dollars. Although the concern over brownfields has traditionally
been the toxicity level of the contamination present, a second factor—the geologic environ-
ment—is perhaps more important and is generally not taken into account. This science
angle exists because the contamination at a brownfield site results from the substances
released on and just below the surface by human activity and their interactions with the
near surface soils and shallow aquifer (Foster 1987; Daly and Warren 1994).
The type of substance released, specifically its toxicity, mobility, and persistence all work
together to determine the potential risks involved with the contamination at a given site. An
area's geology plays an important role in determining the risk posed by any contaminant
released into the environment, since risks also vary depending on the final destination of
certain contaminants. While certain metals such as lead are typically immobile because soils
with clay tend to adsorb it so it does not reach groundwater, lead still poses a significant risk
to children who might put a bit of soil in their mouths. Other contaminants such as hexava-
lent chromium if released into a larger-grained soil type like sand are highly mobile and will
often migrate into groundwater. When this type of event occurs, there are significant poten-
tial risks to the public health and ecology at a larger geographical scale (Murray et al. 2006).
1.4.4 Theme #4: Remediation of Contaminated Sites
Environmental management at industrial facilities has traditionally focused on maintain-
ing compliance with environmental regulations, especially those regulations affecting
production. The emphasis on production-specific regulations has resulted in a higher pro-
portion of inspections targeted at the by-products of the production process (Owen 1995;
Daugherty 1996).
This pattern of industrial compliance and regulatory enforcement has not provided
an effective mechanism for reducing environmental spending. Overall, environmental
spending in the United States continues to increase and represents approximately 2% of
the gross national product or about 150 billion dollars per year (Morgenstern et al. 1998;
USEPA 2004a, 2004b). Of this total, only 25% is associated with compliance-related expen-
ditures, while the remaining 75% is related to other expenses such as investigation and
remediation of existing or historical contamination (Owen 1995; USEPA 2004a, 2004b). In
2004, USEPA estimated there were 350,000 sites of environmental contamination in the
United States requiring remediation within the next 30 years. Furthermore, USEPA esti-
mates that the cost to remediate those sites will exceed $250 billion. Excluded from this
list of 350,000 sites are those sites where remediation is in progress or has been completed.
In addition, there are an estimated 500,000-1 million abandoned industrial facilities or
brownfield sites that are also excluded from the list because a cost estimate to investi-
gate and remediate these sites has not been conducted. Most of these abandoned sites are
located in urban regions in the United States, possess some degree of contamination, and
will require investigation and remediation (USEPA 2004a, 2004b). Thus, it is likely that the
environmental costs to investigate and remediate sites of environmental contamination in
the future will exceed the $250 billion dollar estimate.
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