In the field of environmental consulting conducting Phase I environmental site assessments (or ESA) is very common. This is often the 1st phase in environmental due diligence. The EPA sets the standards in which this process is carried out. The report basically outlines if there is any potential environmental contamination at a site because those who own the property are responsible for it under federal Superfund law. In response to Love Canal, in which was a massive environmental disaster in Upstate New York, the government passed the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) in 1980.  This act forced the clean up of industrial waste sites and made the owners responsible for waste on their property. COnducting an ESA ensures that property owners are protected from this liability. These reports are typically done when a commercial or industrial property purchased to ensure that the buyer is not receiving an environmental disaster that will be very costly to fix. A Phase I ESA may be required from lenders, local banks, or municipalities. They may also be required when applying for a building permit, there is a change in ownership or zoning laws are changing. Sampling of air, groundwater, and soil is not conducted during a phase I ESA. This type of sampling is included in a Phase II ESA which is done if it is evidence of environmental contamination.

The past and current activities are analyzed to conduct a phase I ESA but this is limited to only a visual inspection of the property. An investigation is done to determine what the current and previous activities of the property and surrounding area were. For example, properties may have been used as an auto garage, dry cleaners, or gas station in the past which means that they could have underground storage tanks. Interviews are done with people who are familiar with the property and can provide information about its use. Historical records and aerial photographs are also looked at in addition to private and government documents related to the property. During a Phase I ESA there will be a site visit to look at current activities of the property and nearby areas. The interior and exterior of any buildings are examined as well as nearby properties. Construction materials that have been used will be assessed. Manufacturing processes that use chemicals, underground or above ground storage tanks and auto repair activities put a site at greater risk for contamination. Asbestos, radon gas, lead, and mold are not analyzed as part of a Phase I ESA but the report may note concerns about these substances. This is typically based on the type and age of structures on the property. A Phase I ESA must be conducted by or under the direction of an environmental professional, or EP. To become an EP you need certain levels of education and experience.