Just in time for the New Year, ASTM E1527-13 has been officially approved by the Environmental Protection Agency (EPA). The updated standard practice for the Phase I Environmental Site Assessment process will be effective from Monday December 30. The EPA previously announced ASTM E1527-13’s compliance with all industry regulations, but the new standard was not officially recognized as meeting All Appropriate Inquiry (AAI) requirements until the final ruling on December 30th. The ASTM E1527-13 standard that was adopted is unchanged from the document published in November, but now includes a preliminary statement that addresses public comments, and emphasizes EPA’s position on implementing the new standard. Although the previous version of the standard (ASTM E1527-05) will technically continue to meet AAI, ASTM E1527-13 replaces its predecessor as the industry best practice for Phase I ESAs, and the EPA advises parties seeking to claim protection from liability under CERCLA to follow the updated ASTM E1527-13 format. The new standard introduced a number of key changes including revised definitions for Recognized Environmental Conditions (RECs) and Historic Recognized Environmental Conditions (HREC), a new definition (Controlled Recognized Environmental Condition) as well as stronger recommendations for conducting file reviews and assessing vapor migration risk. Many environmental professionals agree that the updates in ASTM E1527-13 clarify existing language, strengthen the deliverable and reflect good commercial and customary practice, and will thereby improve the quality of Phase I ESAs across the board.