ASTM Standard E1527-13 died quietly on February 13, 2024, after a year of peaceful co-existence with its successor - ASTM Standard E1527-21. Both of the standards, which describe the methodology for conducting a Phase I Environmental Site Assessment, have been accepted under EPA’s “All Appropriate Inquiries” (or “AAI”) Regulation since the new rule went into effect, recognizing the 2021 version of the Standard as meeting the AAI requirement for CERCLA liability defenses. But the revised AAI Regulation established a February 13, 2024 expiration date for the 2013 Standard, thus all Phase I’s conducted after that date must meet the requirements of E1527-21 to satisfy the regulatory safe harbor.

A Phase I Environmental Site Assessment is a critical component of any commercial real estate transaction, since a properly conducted and timely Phase I can effectively shield a new owner from substantial remediation liability for existing environmental issues by providing an affirmative defense to claims. The Maynard Nexsen environmental team has previously covered some of the key differences between the 2013 and 2021 Standard. See our highlight video here. In relevant part, the new Standard broadens the scope of environmental considerations that an environmental professional must include in a Phase I Report, for both the property directly at issue and for adjacent properties that have a potential to contribute contamination onto the subject property.