On October 6, 2014, EPA finalized amendments to the All Appropriate Inquires (AAI) rule to remove references to ASTM International’s E1527-05 “Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process.” As a result, only ASTM’s updated Phase I standard, known as ASTM E1527-13, is referenced in the AAI rule as sufficient to satisfy the AAI requirements for establishing a defense to CERCLA liability. EPA deleted references to the ASTM E1527-05 standard in the AAI rule “to reduce any confusion associated with the regulatory reference to a historical standard that is no longerrecognized by its originating organization as meeting its standards for good customary business practice.” EPA also intends to encourage use of the ASTM E1527-13 standard by making it the only Phase I standard referenced in the AAI rule.

EPA is delaying for one year the effective date of the amendments, until October 6, 2015, to provide parties who are using the ASTM E1527-05 standard to comply with the AAI rule an adequate opportunity to complete ongoing AAI investigations and become familiar with the updated ASTM E1527-13 standard. EPA clarified that removing references to the ASTM E1527-05 standard “does not impact parties who acquired properties between November 1, 2005 and [October 6, 2015] and used the [ASTM E1527-05 standard] to comply with the AAI Rule, as it was in effect at the time the property was acquired.”

For an analysis of the key difference between the E1527-05 and E1527-13 standards, please see our prior client briefing on the subject.