VERTEX has Experts that Talk the Talk and Walk the Walk.

Unlike others, VERTEX provides forensic consulting alongside traditional AEC services which allows for a 360 degree view of your project.

VERTEX Services


Need an expert for your case?

Our forensics experts work alongside AEC specialists which enhances our skills and bolsters the credibility of our expert consultants.

Find an Expert


VERTEX delivers innovative solutions on complex projects globally.

Since 1995, VERTEX has completed over 90,000 projects.

View Portfolio


VERTEX believes in a Lifetime of Learning philosophy.

Stay current with our industry experts as they share their insights and knowledge on the built environment.

View Insights

Grow Your Career

Join Our Team

VERTEX is looking for talented individuals to join a highly technical team of forensic consultants, design engineers, construction managers, and environmental scientists.

Learn More

Contact Us

Have a question or want to speak with a technical professional?

VERTEX is a multi-discipline firm with global coverage. Our international network of resources enables us to provide multi-national clients with the most qualified local professionals who understand the culture, language, and regulatory framework.

Call Us: 888.298.5162

Call Us

Call us at 888.298.5162.

Environmental Consulting

Changes to ESA Phase I Standards – ASTM E1527-21

January 5, 2022

In November 2021, the American Society for Testing and Materials (ASTM) released a new standard practice, E1527-21, for Environmental Site Assessments (ESAs). The standard has been submitted to the U.S. Environmental Protection Agency (USEPA), who are expected to adopt the standard as part of the All Appropriate Inquiries (AAI) rule.

The new ASTM E1527-21 standard was intended to reflect current industry standards, and clarify the practice to provide greater consistency for both consultants and end-users. While the majority of the items in the new standard were already part of VERTEX’s standard environmental due diligence practice, the new standard provides helpful clarifications that reflect the current state of the industry.

For example, the definitions for Recognized Environmental Conditions (RECs), Controlled RECs (CRECs) and Historical RECs (HRECs) have been updated in the new standard to provide greater clarity and consistent interpretations (though the original meaning remains unchanged). A new appendix was added to provide guidance on determining what is a REC vs. CREC vs. HREC, including a flow chart and numerous hypothetical examples to help Environmental Professionals (EPs) and Users understand how to apply the various terms.

Other significant changes to the new standard include:

New ESA Standard Definitions

The terms Likely, Property Use Limitation, and Significant Data Gap are now defined in the terminology section, providing additional clarity for sites with complicated remedial histories, where the difference between a REC, HREC, and CREC may have previously been unclear.  The meaning of the term “likely” (as in, “the likely presence of contamination”) can be found within the REC definition’s discussion and was created to offer guidance and improve the consistency of determining a REC. The new definition states that likely is something that is neither certain nor proven, but can be reasonably believed based on the logic, experience, and/or evidence found by the EP.

ESA Phase I Report Shelf Life

The new E 1527-21 Standard provides important clarifications on the shelf life of Phase I reports. The standard indicates that the Phase I Report will remain viable if it was completed no more than 180 days prior to the date of acquisition (or, for transactions not involving an acquisition such as a lease or refinance, the date of the intended transaction), or up to one year, if five specific components of the Report have been updated. The five components include:

  • Interviews
  • Searches for recorded environmental cleanup liens
  • Review of government records
  • Site reconnaissance of the subject property and adjoining properties
  • The EP Declaration

In addition, the new E1527-21 Standard requires that the dates on which each of the components were completed be identified in the Phase I Report, and that the 180 day or 1-year time period begins with the date upon which the earliest of these components was completed.

User Responsibilities Clarification

In addition to completion of the Phase I ESA, users who want to qualify for CERCLA defenses to liability must satisfy certain user obligations, such as research of title records to identify environmental liens and Activity and Use Limitations (AULs). Under ASTM 1527-21, as was already the case under the previous standard, environmental consultants are not responsible for doing this unless specifically requested by the user to engage the title search on their behalf. Revisions to the ASTM standard provide more robust guidance about the extent of research needed. Previously, searches were sometimes limited to research of the last change in title, which may not be sufficient for identifying environmental liens or AULs. In the new standard, ASTM sought to improve this by clarifying that title records must be researched back to 1980. The EP only needs to identify whether they received land title records from the user and whether the user identified AULs or environmental liens.

Historical review for adjoining properties

Under the 2013 standard, the history of adjoining properties was evaluated based on information collected for the subject property; no additional research or resources were required to fill in gaps in the history for adjoining properties. The 2021 revision now requires an expanded scope of historical research of adjoining properties. The EP will need to review the four main historical resources (aerial photographs, topographic maps, city directories, and Sanborn Fire Insurance maps) that have been reviewed for the subject property for all the adjoining properties, or explain why the review was not completed. The research of additional resources (building department records, property tax files, interviews, and zoning/land use records, etc.) may also be needed when the EP is unable to adequately identify the historical use of adjoining properties based on the review of the four main historical research sources.

Significant Data Gap

The previous E1527-13 Standard required that significant informational or observational-related data gaps be identified in the Phase I ESA Report. However, there often has been confusion among environmental consultants as to what is considered a data gap that is significant enough to impact meeting the objectives of an ASTM Phase I ESA. The new E1527-21 Standard now includes a definition of what constitutes a “significant data gap,” defining it as, “a data gap that affects the ability of the environmental professional to identify a recognized environmental condition.” An example of a significant data gap could include a building that is located on a subject property which is inaccessible during the site reconnaissance, and based upon the EP’s experience, such a building is one that involves activities that can lead to RECs. In addition, the new E1527-21 Standard requires a discussion of how significant data gaps affected the EP’s ability to make conclusions regarding RECs.

Inclusion of Maps/Photographs

While the inclusion of photographs of the subject property and a map that illustrates the boundaries of the subject property was already included in Phase I ESA Reports by most firms, the prior ASTM E1527-13 Standard did not explicitly state that such items should be included in the Report. The new E1527-21 Standard makes it clear that photographs and a subject property map illustrating the boundaries of the subject property shall be included in all Phase I ESA Reports.

Emerging Contaminants

New contaminants of concern, such as per- and polyfluoroalkyl substances (PFAS), have been under scrutiny for possible regulation as hazardous substances by the USEPA and some state agencies for the past several years. While some states have adopted regulatory standards for PFAS, the USEPA has not yet listed PFAS as a federally regulated hazardous substance under CERCLA. The new E1527-21 Standard provides guidance regarding whether environmental consultants are to include emerging contaminants, such as PFAS, in their scope of work when conducting Phase I ESAs, by providing that until an emerging contaminant is regulated as a federal CERCLA hazardous substance, such substances are not required to be included in the scope of an ASTM E1527-21 Phase I ESA. However, the new E1527-21 Standard also indicates that inclusion of such substances can be added to the Phase I ESA as a “Non-Scope Consideration” and be addressed if the user of the Phase I wishes the environmental consultant to do so. This can be particularly important for those Phase I ESAs that are conducted in states that already have adopted regulatory standards for such substances, or in states where the adoption of regulatory standards is anticipated in the near future.

As a leader in the Due Diligence industry, VERTEX is excited by the increased clarity of the new ASTM E 1527-21 standard, which has been designed to improve ESA reports, clarify industry practices, and provide a clearer end product for users. 

The above article happens to be an abridged version of a whitepaper VERTEX distributed to clients. If you are interested in a copy of the full report, please fill out the form below.

Download Whitepaper on Changes to ASTM E1527-21: ESA Phase I Standard Practice (PDF)

Back to Insights