Public Comment Period Open on PADEP's Proposed New Vapor Intrusion Guidance Document

August 18, 2015
Darryl D. Borrelli

The Pennsylvania Department of Environmental Protection (PADEP) has issued its long awaited proposed revision to its guidance document on assessing and addressing issues caused by the migration of volatile organic compounds (VOCs) in soil and groundwater into building interior spaces. The new guidance proposes changes to the original guidance on this topic issued by PADEP in 2004. 

Many of the changes relate to the information needed to properly assess a potential vapor intrusion (VI) situation and the burden that collecting that information will place on the remediating party, especially as it relates to obtaining access to off-site properties.  PADEP has set minimum data needs for assessing VI, and has indicated that these may not be sufficient in all situations and may vary by the type of contaminant present.  There is also a new section allowing for the statistical evaluation of VI data provided that sufficient numbers of data points are acquired. 

The new guidance identifies the process for determining the potential receptors that must be evaluated, which is linked to screening values in soil and groundwater and proximity distances.  Other new sections provide a much more detailed process for evaluating whether preferential pathways for VOCs to travel into buildings are present and how they should be evaluated.

Comments on the revised guidance are due to PADEP by Wednesday, September 23, 2015.  If you would like more information or are interested in submitting comments to PADEP, please contact MGKF partner Michael Meloy; 484-430-2303 or Senior Technical Consultant Darryl Borrelli; 484-430-2302.