Conducted in accordance with federal regulations for the All Appropriate Inquiry Standard (AAI, 40 CFR312) and standards developed by the American Society for Testing and Materials (ASTM, E1527-05), the purpose of conducting a Phase I Environmental Site Assessment (ESA) is to ascertain if vicinity and/or site Recognized Environmental Conditions (RECs) exist that could potentially impact the subject property. RECs include a variety of potential contaminant concerns including Comprehensive Environmental Response, Compensation, and Liability (CERCLA) hazardous substances and/or petroleum products.
In the event that RECs are identified during a Phase I ESA, Phase II ESA activities are conducted in order to ascertain if the subject property has been impacted with contaminants. If site impacts are deemed likely, a Phase II is often included as part of the Phase I in order to help suppress costs.
In order to delineate the vertical and horizontal extent and the source of a contaminant release (e.g. petroleum), a variety of field techniques similar to those used for hydrogeologic characterization investigations are used. However, in order to expedite soil and groundwater remediation activities, soil excavation and disposal activities are used. The extent of soil removal is based upon field instrumentation results of soil screening conducted during excavation. In the event that “free product” is observed on groundwater that enters the excavation, a vac truck can be used to remove and transports the product to a disposal facility.
Following initial soil removal activities and based upon water quality, additional groundwater remediation may be required. Based upon site conditions, a variety of techniques may be used including pump and treat (air stripping, granular activated carbon treatment) to provide hydraulic control, air sparging and extraction, biodegradation, and natural attenuation.