On December 15, 2022 U.S. EPA published its long-awaited final rulemaking updating its regulations on the All Appropriate Inquiries standard to incorporate by reference ASTM 1527-21. The final rule goes into effect February 13, 2023.   

As covered previously, ASTM 1527 sets standards for environmental site assessments, typically required as part of real estate transactions. The ASTM 1527 standard is particularly relevant to environmental due diligence because federal regulations state that compliance with the ASTM 1527 standard is one way to satisfy All Appropriate Inquiries, a required element of certain CERCLA statutory defenses to liability.

The previous version of the standard, ASTM 1527-13, was replaced with ASTM 1527-21 in late 2021. U.S. EPA originally proposed a rule that would allow compliance with both versions to satisfy All Appropriate Inquiries, however, commentators raised concerns that unnecessary cost comparisons between bidders under the two standards would be required and the standard would not be consistent because of the differences in -13 and -21, among other issues. As a result, U.S. EPA withdrew that rulemaking to prepare a final rule and address the comments.

As published, the final rule adopts ASTM 1527-21 as compliant with All Appropriate Inquiries under the regulations. Critical, however, is U.S. EPA’s recognition that a transition period is needed for due diligence and Phase I site assessments already underway at the time of publication. Therefore, the final rule provides that ASTM 1527-13 may be used as compliant with All Appropriate Inquiry until February 13, 2024, one year after the effective date of the final rule.