Environmental Assessment 

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. The EPA's 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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