Remediation: Techniques and Cost - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 377

11
Remediati on:TechniquesandCost
11.1 Introduction
Contaminants released into the environment often require cleanup to reduce or eliminate
the risks posed by their presence. This cleanup, termed remediation , meaning remedy,
varies widely and depends on many different factors.
More than $100 billion dollars is spent annually investigating and remediating contami-
nated sites in the United States (USEPA 2004). In 2008, the USEPA estimated that there
were well over 350,000 sites of environmental contamination in the United States requiring
remediation. Excluded from this count were 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 also excluded from USEPA's list, because a cost esti-
mate to investigate and remediate brownfield sites has not been conducted. Most of these
abandoned industrial sites are located in urban areas of the United States and concen-
trated within the 29 urban areas listed in Table 2.4. Since these sites possess some degree
of contamination and will likely require some form of remediation (Rogers et al. 2006), it
is likely that the environmental costs to investigate and remediate sites of environmental
contamination in United States will exceed the latest available USEPA estimate of (U.S.)
$250 billion.
The following sections describe some of the more common remedial technologies for
soil, groundwater, surface water, sediment, and air. As with any remedial strategy, control-
ling the source of contamination is critical for success, because failure to control the source
of contamination will result in recontamination. The chapter concludes with a cost analy-
sis of remediating common contaminants in the environment, including many described
in Chapter 7.
11.2 Remediation Overview
The objective of any remediation project is to prevent, remove, treat, change, destroy, or
transform the potentially harmful contaminants from the medium or media of concern so
that any risks posed by the contaminants have been effectively eliminated or reduced to
an acceptable level (USEPA 2005a). As noted in Chapter 4, there are several different stud-
ies conducted at a site of environmental contamination that enable investigators to acquire
relevant information and navigate through the required field procedures for achieving the
desired goal or objective. Even with a given set of checks and balances, however, many
remedial projects are unsuccessful and must be revised or abandoned in favor of a differ-
ent technological approach.