Environmental Site Assessments (ESAs) are an important tool to assess liability for commercial property buyers, lenders, and lessors. They are designed to identify potential or existing environmental contamination that may present liability to the seller, buyer, lessor, and/or lender. In a series of decisions, the courts determined that the Comprehensive Environmental Response, Compensation and Liability Act of 1980 (CERCLA) can be used to hold owners, lenders, and lessors responsible for remediation of hazardous environmental conditions, even if they did not cause the condition. The same determination, however, provides a “safe harbor” provision called the “Innocent Landowner Defense.” This clause provides protection if the owner, lender, or lessor can show that they performed adequate due diligence prior to the purchase. Environmental Site Assessments (ESAs) are designed to provide the protection of “safe harbor,” as well as to alert owners, lenders, and lessors to potential problems.