The environmental assessment process consists of a preliminary
investigation and sampling
and analysis in order
to determine the potential and actual contamination or pollution
present. The purpose of a preliminary investigation is to collect
and review existing information to determine the possibility of
contamination or pollution. The sampling and analysis focus on confirming
whether any contamination exists, locating the contamination, and
characterizing the nature and extent of contamination.
Once a preliminary investigation is completed and the past uses
of the property (e.g. types of industry) have been defined, it is
possible to develop a short list of possible contaminants. For example,
the dry cleaning industry uses solvents in the cleaning process.
The four main types of solvents are perchloroethylene (PCE), petroleum
solvents, chlorofluorocarbons (CFCs) and trichloroethane (TCA).
Although CFCs and TCA have been banned since 1995, any one of these
four contaminants are likely to be found on-site. The EPA's Office
of Enforcement and Compliance Assurance (OECA) has developed the
EPA Sector Notebooks
to provide chemical profiles of selected industries. Each profile
includes information about the processes conducted in the industry,
chemical releases and transfers of chemicals, opportunities for
pollution prevention, pertinent federal statutes and regulations,
and compliance initiatives associated with the sector. Please refer
to Pollutants for more information.
If contamination is suspected, a sampling
and analysis should
be conducted. Sampling may include soil, groundwater, surface water,
sediment, building materials, waste products and debris.
The purpose of this step is to develop a reasonably comprehensive
understanding of what contaminants are present, where they are located,
and at what levels they are found. This is accomplished using field
analytical technologies, which measure chemical concentrations
on-site, and by collecting samples from the site, and analyzing
them at an environmental laboratory. In addition, a variety of other
techniques are normally used to evaluate physical characteristics
of the site that may be relevant, such as the direction of groundwater
flow, surface slope, and the presence of buried materials.
Once data is collected, the site can be evaluated based on the
State and/or Federal cleanup requirements. Refer to Regulations
for more information.
An environmental assessment may be performed for a variety of reasons
such as the implementation of public environmental health legislation,
the redevelopment of land, a property transfer, financing or legal
liabilities. In order to assure that the ESA process is completed
in compliance with accepted commercial and professional standards,
several companies and organizations have developed protocols for
various phases of the ESA process. Among the professional organizations
which have developed or are developing standards for conducting
ESA are: American Society for Testing Materials (ASTM); The Association
of Engineering Firms Practicing in the Geosciences (ASFE), National
Groundwater Association, and the Hazardous Waste Action Coalition.
For many of these steps, an environmental contractor is required.
Brownfield Technology Support Center provides assistance in
evaluating the capabilities of environmental consultants. This resource
also identifies potential activities that contractors can perform
to enhance the site investigation process through innovative approaches.
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