Key Revisions to the Phase I Environmental Site Assessment ASTM E1527 Standard

It is no secret that a revision to the American Society of Testing and Materials (ASTM) Phase I Environmental Site Assessment (ESA) E1527 standard (Standard) is on the horizon.  In fact, ASTM anticipates release of the revised Standard within late spring 2013, and once released the revised Standard will be effective immediately.  The revised Standard will still be compliant with the United States Environmental Protection Agency (USEPA) All Appropriate Inquiry (AAI) Final Rule.

With this revision, several key changes to the Standard can be expected including further defining recognized environmental conditions (RECs), considerations for vapor migration and the need to complete regulatory file reviews.  Further details of these key changes are described below.


The need for further definition of a REC is driven primarily by an increasing trend in risk-based corrective action at contaminated properties.  The concept of risk-based corrective action is to reduce risks to human health and the environment.  Reducing risk does not necessarily need to include traditional remedial approaches such as a removal action or “dig and haul”, which can be costly, but rather, may involve utilizing engineering controls like constructing a cap over the impacted media (e.g. building slab, paved parking lots, etc.) which tend to be more cost effective and as protective as the traditional approaches.

Under the revised Standard, we can expect further definition of the Historical RECs (HRECs) and creation of a Controlled REC (CREC).  Under the 2005 Standard, HRECs are generally defined as environmental conditions that would be considered a REC in the past, but may or may not be currently considered a REC.  Often times Environmental Professionals (EPs) do not recommend further investigations or actions with HRECs.

An example of an HREC under the earlier 2005 Standard would be a situation where contaminated soil was identified at a given property that was mitigated by a soil removal action and completed to the satisfaction of the associated regulating agency.  Under the new Standard, this scenario may still be considered an HREC; however, further investigation to evaluate the conditions in which regulatory compliance was granted may be warranted due to an expected expanded definition of an HREC.  Under the new definition, an environmental condition could be considered an HREC only if the property can be utilized for unrestricted residential land.  This proposed new definition could warrant additional investigation with the aforementioned removal action scenario as there is no mention of an unrestricted residential land use.  Therefore, this former HREC would now be considered a REC under the new definition.

A CREC definition is expected to be included in the revised Standard.  Generally, the CREC would be defined as a REC resulting from a past release that has been addressed to the satisfaction of the associated regulating agency, but is controlled in place by acceptable mitigating measures such as engineering controls, land use restrictions, etc.  The CREC definition is a direct result of the trend observed in risk-based corrective action described above.  While still considered a REC, in most cases the EP would not recommend further investigations or actions associated with a CREC provided the control measures in place are properly maintained.

Vapor Migration

The potential for vapor migration at a property is expected to be evaluated in ESAs as part of the revised Standard based on the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) understanding of a release being either in solid, liquid or vapor form.

The methods by which the potential for vapor intrusion will be evaluated can be determined by the EP; however, the method must be documented in the report submittal.  The ASTM E2600‑10 standard for Vapor Encroachment Screening on Property Involved in Real Estate Transactions is generally utilized by EPs to evaluate the potential for vapor migration at a property for a Phase I ESA.

Regulatory File Reviews

A new section describing instances that may warrant conducting regulatory file reviews is expected to be included in the revised Standard.  Conducting a regulatory file review will be recommended for subject properties and adjacent properties that are identified in a regulatory database such as a leaking underground storage tank (LUST) database, CERCLA database, etc.  The need to complete a file review for either the subject property or an adjoining property will be determined by the EP.  However, should the EP elect to not conduct a regulatory file review in these instances, justification will need to be discussed in the report submittal.  Instances where a review of regulatory information might not be necessary or feasible would include report deadlines, increased costs and current regulatory status.

While changes to the Standard are imminent, Arc Environmental has been following the progress of the Standard revision, and already routinely considers the vapor intrusion pathways and need to review file information, where necessary, when completing a Phase I ESA.  Arc Environmental is fully prepared to address these expected key changes to the Standard and can provide assurances that there will be no learning curve or delays in our report submittals.

 If you are considering an ESA, or would like additional information about these changes, please contact David Leety at 410-659-9973,