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EPA Takes Final Action to Amend 'All Appropriate Inquiries Standard' for Phase I ESAs

In the December 15, 2022, Federal Register ( FR 76578), EPA took final action to amend the All Appropriate Inquiries Rule (AAI Rule), 40 CFR part 312, to recognize the updated ASTM International standard for conducting Phase I environmental site assessments (ESAs), ASTM E1527-21, “Standard Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process.” This action allows the updated ASTM standard to satisfy the requirements for conducting all appropriate inquiries under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). The new standard takes effect on February 13, 2023.

To eliminate confusion that could result from having two acceptable standards, EPA's final action also removes the current standard ASTM E1527-13 one year following the adoption of the new rule (i.e., on February 13, 2024).

Background on the All Appropriate Inquiries Rule

The AAI Rule sets federal standards for the conduct of ‘‘all appropriate inquiries’’ at 40 CFR part 312 and specifies standards and practices necessary for fulfilling the requirements of CERCLA Section 101(35)(B) to obtain CERCLA liability protection and for conducting site characterizations and assessments.

Conducting an ESA Between Now and February 2023?

Until the E1527-21 is codified in EPA’s rules, it is recommended to use and cite E1527-13 as the standard followed in report, but also note that the assessment satisfies the requirements of the E1527-21 standard. If the Phase I ESA does not follow the E1527-21 standard, note the “Significant Data Gaps” in the conclusions. A data gap is not in itself significant; however, if it hinders the ability to form an opinion on a recognized environmental condition, then it may be considered significant. Examples include the inability to access buildings on the Subject Property or interview key personnel. 

An Item to Watch

The new standard includes clarification on how Phase I ESAs can address per- and polyfluoroalkyl substances (PFAS) and other emerging contaminants as “non-scope” items since EPA has not yet listed PFAS as a CERCLA hazardous substance. Thus, a prospective purchaser may, but is not federally required to, address PFAS in a Phase I ESA to conduct AAI.  Different states may have different requirements depending on any state-specific PFAS standards in place.

Interested in Learning More?

Watch for a follow-up article in the New Year with additional details on the use of the 2021 standard. If you have questions in the interim, please get in touch with us using the form linked below!

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Kelly Birkenhauer, PG, CP
Project Manager/Geologist, Cincinnati, OH

Kelly is a geologist and OEPA VAP CP with 14 years of experience in environmental consulting. She has conducted and managed multiple client projects focused on sustainability initiatives including CDP reporting, DoD Qualified Recycling Programs, and waste management minimization projects.
Rajib Sinha, PE
Senior Engineer, Cincinnati, OH

Rajib is a chemical engineer with 30 years of experience in environmental engineering. He provides technical expertise and compliance support for the investigation and remediation of sites contaminated with hazardous materials and petroleum contaminants.
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