Author: Jennifer A. Ewing, P.G.

PADEP’s New (and Improved) Vapor Intrusion Guidance

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Are you buying a property in the city? Have you been informed that the property is being sold at a reduced rate, but were not given a reason why? Is it possible that there was a release from a facility near your property? Depending on the concentrations and site conditions, volatile substances in the subsurface could potentially result in vapor-phase intrusion of these substances into inhabited buildings at a level that poses a threat to human health.

PADEP’s updated Vapor Intrusion (VI) Guidance, entitled “Land Recycling Program Technical Guidance Manual (TGM) for Vapor Intrusion into Buildings from Groundwater and Soil under Act 2,” became effective January 18, 2017. The TGM provides guidance for implementing the Pennsylvania Code Chapter 250 regulations (Pennsylvania’s Voluntary Cleanup Program, commonly known as Act 2). As a property owner (referred to as “remediator” in the TGM), you will be expected to implement the new VI Guidance in order to satisfy the requirements of Act 2 for any Act 2 reports submitted after January 18,2017.

The VI Guidance outlines significant changes to the process for addressing VI that include new/clarified key terms and more options to comply with the Act 2 Statewide Health and Site-Specific Standards. Some benefits of the new VI Guidance include separate approaches for petroleum versus non-petroleum constituents, additional alternative assessment options (near-source and sub-slab soil gas screenings), and details regarding addressing VI under the Act 2 Site-Specific Standard.

In general, the VI assessment process under the new VI Guidance initially includes development of a Conceptual Site Model (CSM) and delineation of concentrations of soil and groundwater constituents, followed by screening of potential VI sources via identification of preferential pathways and application of proximity distances as described in the TGM.

Mitigation (elimination of the complete pathway between the contamination source and the receptor) may be used at any time during the process, and it can be used in lieu of a complete evaluation of the VI pathway.

The remediator chooses from the following options if potential VI sources are identified: (1) alternative VI assessment options (near-source soil gas screening, sub-slab soil gas screening, indoor air screening, or VI modeling); (2) mitigation with an Environmental Covenant; (3) remediation and re-evaluation of the VI pathway; or (4) selection of the Act 2 Site-Specific Standard.

Some of the new/clarified terminology in the VI Guidance that may be important to consider during your building design phase and/or when evaluating existing on-site buildings include Potential VI Source, Preferential Pathway, External Preferential Pathway, Significant Foundation Opening (SFO), Point of Application (POA), and Proximity Distance.

Preferential pathways considered in consort with POA and proximity distance as it relates to the horizontal and vertical location of the potential VI source could be utilized to address potential VI when siting and designing future buildings at the site. When identified, SFOs in existing buildings at the site could be sealed to inhibit vapor entry. Depending on your proposed plans, mitigation may be a more favorable option for your particular scenario with regards to schedule.


PADEP’s new VI Guidance provides a more-detailed process for satisfying Act 2 requirements and additional options for addressing VI to those who wish to obtain a release of environmental liability from the PADEP. Understanding how to apply the process and evaluate options could possibly save you time and/or money.

Please contact Jennifer A. Ewing, P.G., ( or Mary A. King, P.G., ( at 800-365-2324 if you have any questions about the new VI Guidance and how it may influence an upcoming project, or about Act 2 in general.

Modifications to the Phase I ESA Process – Part 2

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A December 30, 2013, EPA final rule (78 FR 31112) amended 40 CFR Part 312 (All Appropriate Inquiries [AAI]) to reference ASTM International’s E1527-13 Standard Practice for Environmental Site Assessments:  Phase I Environmental Site Assessment (ESA) Process.  The AAI amendment was effective December 30, 2013.

Per the final rule, EPA recognizes the newly issued ASTM E1527-13 as compliant with AAI.  Therefore, “persons conducting all appropriate inquiries may use the procedures included in the standard to comply with the All Appropriate Inquiries Rule.”

ASTM published the revised E1527 standard on November 1, 2013. ASTM E1527-13 reflects the consensus of its technical committee, and as such is the industry-accepted standard of care for conducting Phase I ESAs.

EPA stated that “the ASTM E1527-13 standard is similar to the ASTM E1527-05 standard in format, process, and areas of coverage.” In general, the revisions included:

  •  New and revised terminology related to Recognized Environmental Conditions (RECs)
  • Clarification related to the applicability of the vapor pathway to ASTM E1527
  • Language regarding file reviews including agency file reviews and judicial records

EPA’s amendment offers the option of using ASTM E1527-13 to conduct all appropriate inquiries; however, the December 30, 2013 rule does not require use of ASTM E1527-13. Although not required, EPA’s final rule included the following:

  •  “ASTM E1527-13 provides an improved process for parties who wish to undertake AAI.”
  • The “changes enhance the usefulness of the standard” in identifying potential and threatened releases
  • “ASTM E1527-13 improves upon the previous standard and reflects the evolving best practices and level of rigor that will afford prospective property owners necessary and essential information when making property transaction decisions”
  • “EPA views these enhancements and clarifications to the ASTM standard as valuable improvements and strongly encourages prospective purchasers of real property to use the updated ASTM E1527-13 standard”
  • “EPA recommends that environmental professionals and prospective purchasers use the ASTM E1527-13 standard.”

Additionally, EPA also announced its intent to publish a proposed rule, in the near future, that will propose removing the previous reference to the 2005 standard from AAI; thus supplanting the 2005 standard with the 2013 standard.

If you have any questions about ASTM E1527-13 and how it may impact an upcoming project or Phase I ESAs in general, please contact Jennifer A. Ewing, P.G., ( at 800-365-2324.

Upcoming Modifications to the Phase I ESA Process

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A recent EPA ruling (78 FR 19764) indicates that 40 CFR Part 312 (All Appropriate Inquiries [AAI]) will be amended to reference ASTM International’s E1527-13 Standard Practice for Environmental Site Assessments:  Phase I Environmental Site Assessment (ESA) Process.  The AAI amendment is tentatively set to take effect on November 13, 2013.

Although not published by ASTM yet, the proposed 2013 revisions to ASTM E1527 are expected to be as follows:


The definition of a Recognized Environmental Condition (REC) will be streamlined.  The pending revision of the term states a REC means the presence or likely presence of any hazardous substances or petroleum products in, on, or at a property:  (1) due to any release to the environment, (2) under conditions indicative of a release to the environment, or (3) under conditions that pose a material threat of a future release to the environment.

In addition, the “Historical Recognized Environmental Condition (HREC)” will be clarified to specifically apply to sites where a past release of hazardous substances or petroleum products has been addressed to the satisfaction of the applicable regulatory authority or meeting unrestricted residential use criteria established by a regulatory authority, without subjecting the property to any required controls such as property use restrictions, activity and use limitations (AULs), or  engineering or institutional controls.

A new term you will be seeing in Phase I ESAs is “Controlled Recognized Environmental Condition (CREC).”  A CREC is a REC resulting from a past release of hazardous substances or petroleum products that has been addressed to the satisfaction of the applicable regulatory authority with hazardous substances or petroleum products allowed to remain in place subject to the implementation of required controls.  The required controls (i.e., property use restrictions, AULs, engineering or institutional controls, etc.) likely pose ongoing and/or future obligations for the property owner.  This terminology will be especially important to Users who intend to redevelop a property because contamination remains in place.

The Vapor Pathway

ASTM E1527-13 will also clarify that the definition of “migration” includes contamination in the vapor phase.  Although a tool for assessing vapor migration risk, ASTM E1527-13 does not require that an ASTM E2600 Vapor Encroachment Screening be performed in conjunction with a Phase I ESA.

File Reviews

The 2013 revision of ASTM E1527 will also include language regarding regulatory file reviews for the subject property and adjoining properties.  Although the Environmental Professional (EP) is not required to conduct such file reviews, ASTM E1527-13 will state that pertinent regulatory files and/or records associated with the subject property or any adjoining properties identified in the government database search should be reviewed.  Therefore, the EP must cite rationale why such file reviews are not necessary if not performed in conjunction with the Phase I ESA.  Agency file reviews can be an inconvenience when it comes to the cost and timing to obtain the files.  Acceptable alternatives will include review of onsite records, User-provided records, local government records, and/or interviews with regulatory officials or individuals knowledgeable about the environmental condition that resulted in the database listing.

Although the environmental lien/AUL search will still be identified as the responsibility of the User in ASTM E1527-13, wording related to the search for environmental liens and AULs that are filed or recorded against the subject property will be revised to include the need to search judicial records in jurisdictions where environmental liens and AULs are only recorded or filed in judicial records.


Once ASTM E1527-13 is published, you can expect to see the use of some new and revised terminology, a new emphasis on vapor migration, and the EP’s judgment regarding the applicability of file reviews to specific projects.

If you have any questions about E 1527-13 and how it may impact an upcoming project or Phase I ESAs in general, please contact Jennifer A. Ewing, P.G., ( at 800-365-2324.

ASTM Vapor Encroachment Standard May Affect the Phase I ESA Process

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Vapor intrusion is becoming a more prominent factor in the Phase I Environmental Site Assessment (ESA) process that is typically used during real estate transactions.  Vapor intrusion is defined by the U.S. EPA as the migration of volatile chemicals from the subsurface into overlying buildings.  The focus on vapor intrusion has increased because of the issuance of a revised vapor intrusion standard in 2010 by ASTM, the adoption of an earlier version of that standard by one government agency in 2009, and a general increased focus on vapor intrusion by environmental agencies.

Previously, vapor intrusion risks may or may not have been considered by environmental consultants when identifying recognized environmental conditions (RECs) during the Phase I ESA process because the evaluation of vapor intrusion risks was not specifically required.  ASTM has now formalized a vapor encroachment screening process which is intended to be considered during real estate transactions.  That standard, ASTM Standard Practice E 2600, was first issued as Standard Practice for Assessment of Vapor Intrusion into Structures on Property Involved in Real Estate Transactions in 2008, then extensively revised and renamed Standard Guide for Vapor Encroachment Screening on Property Involved in Real Estate Transactions on June 1, 2010.

E 2600 states “the purpose of the guide is to provide practical guidance and a useful process for conducting a vapor encroachment screen (VES) on a property parcel involved in a real estate transaction in the United States of America….”  The goal of the vapor encroachment screening (VES) “is to identify a vapor encroachment condition (VEC), which is the presence or likely presence of COC vapors in the subsurface of the target property caused by the release of vapors from contaminated soil or groundwater either on or near the target property as identified by Tier 1 or Tier 2 procedures.”  The two-tiered VES process utilizes information similar to that obtained during a Phase I ESA.  Information collected during a Tier 1 VES includes:

  • Federal, state, local, and tribal government records;
  • Chemical use and historical records of prior uses on the property and within the area of concern;
  • Soil, geological, and contaminant characteristics;
  • Contaminant plume migration and conduits possibly providing preferential pathways;
  • Groundwater depth and flow direction data; and
  • Property information data.

A Tier 2 VES is a more refined screening that uses numeric data obtained through file/existing document reviews or collected via invasive sampling of soil, soil gas, and/or groundwater.  The findings of the VES are used to develop opinions on whether a VEC exists, likely exists, or cannot be ruled out.  The results of the VES can be presented in the Phase I ESA report if the VES is performed in conjunction with a Phase I ESA.

As stated in the guide, the use of E 2600 is voluntary and does not alter U.S. EPA’s All Appropriate Inquiry requirements, nor does it necessarily address requirements of federal, state, or local laws with respect to vapor intrusion.  ASTM states that E 2600 is not to be a replacement for Practice E 1527 and that the VES can be performed independently of or in conjunction with Practice E 1527.  It is not known whether or not the ASTM task group reviewing the Standard Practice for Environmental Site Assessments (E 1527) will incorporate by reference the E 2600 Guide into the Phase I ESA process when E 1527 is re-issued.

The U.S. Department of Housing and Urban Development (HUD) decided in 2009 to require a Tier 1 screening in accordance with E 2600 for Phase I ESAs of multifamily properties prepared per the specifications outlined in their MAP (Multifamily Accelerated Processing) Guide.  Time will tell if other Phase I ESA users such as lenders, insurers, or other agencies will follow suit especially in light of HUD being the first federal agency to require the screening to be completed as part of a Phase I ESA.

So you may ask, “Do I now need to add a VES to my Phase I ESA?”  ASTM encourages discussions between the environmental consultant and the Phase I user to decide whether a VES is appropriate and/or recommended for the project.   Heavy emphasis is placed on the opinion of the Environmental Professional (EP) on the need for the VES and at what phase of the project it should be implemented.  This suggests that it is very important for the EP to understand the objectives of the Phase I user and their scope and schedule limitations for the assessment activities.

The impacts to the Phase I ESA process by E 2600 and its adoption as standard practice by HUD, as well as the possibility of its incorporation into the update to E 1527, will need to be followed closely in the coming months.  There are also unknowns associated with the use of E 2600 that can only be evaluated through it implementation and legal precedence.

CEC will follow this issue as it continues to develop and will provide periodic updates as needed.  In the meantime, should you have any questions about E 2600 and how it may impact an upcoming project or ESAs in general, please contact Jennifer A. Ewing, P.G. ( or Mary J. Guinee ( in the Pittsburgh office at 800-365-2324 or Jim Zentmeyer ( in the Cincinnati Office at 800-759-5614.