An environmental site assessment (Phase I) is a review of current and historical site use to flag potential environmental contamination.
A Phase I ESA reviews records, past uses, and a site visit to identify recognized environmental conditions, such as a former gas station or dry cleaner on or near the site. It does not involve soil or groundwater sampling. If it raises concerns, a Phase II with sampling may follow. Lenders often require one, and completing a proper assessment may help support certain liability protections under federal law. For NNN properties with fuel, automotive, or dry-cleaning uses, it is especially important.