Environmental Site Assessments (ESA)

Working Cooperatively to Investigate, Assess, and Screen Property

Environmental site assessments (ESAs) have become an important component of real estate transactions, especially for commercial and industrial property. Through its program of new highway construction and improvements to existing roadways, the Illinois Department of Transportation (IDOT) must acquire properties that have the potential for environmental problems. Sites of interest can include various natural and man-made hazards that may be present on existing IDOT right-of-way or on sites proposed for acquisition.

The Illinois State Geological Survey (ISGS) has developed and tested for IDOT a site assessment program that provides information on environmental conditions associated with highway projects. Site assessments conducted by ISGS for IDOT are referred to as Preliminary Environmental Site Assessments (PESAs), as they differ from industry standard ESAs. IDOT uses the information provided in the PESA reports to help determine the costs of various design alternatives (and thereby reduce project costs), to help determine the needs to ensure worker safety, to better determinescheduling, and to help prioritize their projects relative to available funding.