A good Phase I Environmental Site Assessment(ESA) combines raw data andobservations with appropriate analysis and interpretation.Therefore, in order for the ESA report to meet its goals, theenvironmental professional (EP) conducting thePhase I ESA must not only conduct accurate historical andregulatory research, but should also use critical thinking skillsto make sense of the data and draw appropriateconclusions.

EPs, put your thinking caps on!

How an EP interprets data determines the results and validity ofa Phase I ESA report. An EP should assessall aspects of a site – including but not limited to the sitehistory, regulatory documentation, interviews and the site'sgeology and hydrogeology – to be able to properly assess the siteas a whole. When one or more of these areas is not thoroughlyresearched, the analysis of the data can be skewed by the EPspersonal knowledge or experience. This can result in wrongconclusions, or unnecessary additional work.

An Interesting Case Study

At a conference I recently attended, an interesting case studywas presented which nicely illustrates my point. A Phase II Subsurface Investigation wasconducted at a site that resulted in its inclusion on the EPA'sNationalPriorities List (NPL) because of extensive pesticide andherbicide contamination. A nearby former pesticidemanufacturing facility was quickly identified as the obviousresponsible party to be held liable for the clean-up.