February 03

Vapor Intrusion Exposure Concerns Could Cause Sites to Be Reopened

Vapor Intrusion (VI) has become a routinely addressed environmental exposure issue within the past few years.  Especially at sites where a spill of Tetrachloroethene (PERC) or Trichloroethylene (TCE) has occurred. Many state environmental agencies have provided guidance on dealing with VI issues, and now the US EPA has recently finalized their guidance for use at federal sites.  In prior years, however, assessment of the VI exposure pathway was often excluded from a site’s investigation and remediation process. Since VI was not really on the regulator’s radar, many sites achieved closure without VI having   been evaluated.  As VI has become a routine part of environmental investigations, regulatory agencies are now beginning to reassess closed sites to see if VI exposure issues have been inadvertently missed.  Very recently, it has been reported that the Indiana Department of Environmental Management (IDEM) has joined other states in reopening closed sites that warrant further assessment for VI risk.

EnviroForensics stresses to our clients and regulatory agencies the importance of a well-planned environmental investigation and remediation process — which includes a thorough VI assessment. Since many of our clients are dealing with, or have previously dealt with releases of PCE or TCE, the concern that VI exposure could be present is very real. Whether responsible parties are just embarking upon the investigation process, in the midst of the cleanup process, or approaching regulatory closure, an awareness of the importance of VI assessment and mitigation is paramount to managing risk and liability.

If you are near the point of site closure, you and your consultant should determine which continuing obligations will be required by IDEM. Once remediation is complete, all VI pathways and ongoing mitigation should be clearly outlined and understood by all parties involved. However, it is possible to eliminate the need for continuing obligations for the VI pathway if it has been thoroughly evaluated and remediated. This point is especially compelling when dealing with releases of PCE and TCE since these compounds are very resistant to degradation under naturally occurring conditions in the subsurface environment. In other words, if PCE or TCE were present at levels high enough to be of concern for VI exposure back when a site may have been closed without VI assessment, the risk is likely still present.

Not only is it extremely important to follow the contemporary guidance for VI assessments in support of investigation, remediation and closure for PCE and TCE sites, it is also prudent to have an expert look at your closed site files to perform a preemptive assessment of potential VI issues.  That way, if the regulatory agency has a look at your closed site and considers reopening it, you can be a step ahead.  EnviroForensics is among the nation’s leaders in vapor intrusion and sites contaminated with PCE and TCE. Our VI team is highly skilled in handling VI assessment and mitigation. We utilize our expertise as well as a line of specialized, field-based, analytical tools to obtain the necessary details during VI assessments. We are successful in handling all VI concerns for our clients’ sites and ensure that our work is approved by state and local regulatory agencies. If you are concerned that your closed site may be subject to reopening, we can help put your mind at ease.

About the Author

Jeff Carnahan, L.P.G.

Vice President, Chief Technical Officer

Jeff Carnahan is a Licensed Professional Geologist (LPG) with over 18 years of environmental consulting and remediation experience.  In his role as Chief Technical Officer, Jeff encourages and upholds the superior level of technical expertise found at EnviroForensics.  His expertise has focused on the investigation and interpretation of subsurface releases of hazardous substances for the purpose of evaluating and controlling the risk and cost implications to his clients.  He has amassed extensive experience working with releases of chlorinated solvents within voluntary and enforcement cleanup programs for various State agencies and the U.S. EPA. Throughout his career Jeff has provided technical support to the legal community regarding the cause, origin, timing, and cost of environmental releases.  His litigation and expert opinion experience has focused primarily on chlorinated solvents and cost-recovery claims on behalf of insurance policyholders.  Additionally, Jeff has over 14 years of experience in the investigation and mitigation of vapor intrusion issues and oversees the VI Assessment Team at EnviroForensics.