Interview With : Jeff Carnahan, LPG, Vice President, Director of Technical Services at EnviroForensic
Updated on: 13 Sep 2013
This is the transcript of our recent interview with Jeff Carnahan, LPG, Vice President, Director of Technical Services of EnviroForensics, Expert on Perchloroethylene Investigation and Remediation.
Jeff Carnahan is a Professional Geologist with over 15 Years of Technical Environmental Consulting Experience. He develops detailed conceptual site models for subsurface releases of industrial chemicals where complex geologic conditions and multiple human exposure pathways exist. His areas of technical practice include Subsurface Investigation & Remediation, Vapor Intrusion Assessments and Mitigation, Environmental Litigation Technical Support, Chlorinated Solvent Investigation and Remediation, Voluntary Cleanup Programs and Leaking Underground Storage Tanks. A part of his business experience covers Direct Sales & Marketing, Client and Emerging Market Development and Budget Forecasting & Management.
Jeff Carnahan is a graduate of Indiana University-Purdue University at Indianapolis.
JRCC : With what kind of risks is EnviroForensic dealing with ?
Jeff Carnahan: EnviroForensics is an environmental consulting firm with specialty in dealing with historical, subsurface releases of chlorinated solvents. Given the chemical nature of these contaminants (i.e. TCE and PCE), often times contamination migrates away from my client's controlled property and onto privately owned properties. The contaminated media are typically soil, groundwater and soil gas (vapor). Both PCE and TCE are toxic chemicals so there may be human exposure concerns (ingestion, direct-contact or inhalation) for off-site property owners, for which my clients may be held responsible. The risks in these scenarios are either actual human health risks to potentially exposed populations, or liability risks from the perspective of the responsible party.
Since chlorinated compounds are considered recalcitrant (i.e. they don't readily break down in the environment) and they are volatile, contaminated soil gas often leads to vapor intrusion (VI) problems at occupied structures near our sites. The occurrence of VI at an occupied structure immediately results in the inhalation of impacted air by those occupants. As such, every one of EnviroForensic's sites contains a potential VI and Risk Communication component.
JRCC: What is the operational part and what can be described as the communication part of your work?
Jeff Carnahan: The primary objective for the operational component is to investigate the nature and extent of contamination in all impacted subsurface media, and to devise and implement a remedial approach to reduce impacts to below health-based levels. This process is undertaken within the applicable environmental guidance and regulations for the State or Federal Region in which the site resides. Although communication with regulators is an important component of this process, it is mostly technical in nature.
The communication portion most typically includes:
? Approaching off-site property owners and occupants to inform them of the process we are undertaking and request access to their property or structure for additional sampling;
? Informing off-site parties of the results of sampling
? Explaining any existing exposure concerns
? Proposing any necessary exposure mitigation or elimination measures
JRCC: Can you describe in more detail the Vapor Intrusion mitigation system ?
Vapor Intrusion Mitigation systems commonly take the form of a sub-lab depressurization system, or SSDS, in practicality, they are very similar to those systems that you may have seen installed to address radon gas concerns at buildings. Radon gas is very analogous to impacted subsurface vapors in the way they move, just that radon is naturally occuring and the impacted vapors are from contamination.
Please have a look at a video clip of me explaining how SSDS works for a site in Wisconsin:
JRCC: Do you feel that the public at large and the public most concerned is aware of the risks?
In my experience, most of the general public is not fully, or correctly informed of the true risks associated with exposure to environmental contaminants. In fact, most environmental consultants don't truly grasp the intricacies of risk assessment and toxicological studies.
JRCC: What is the best way to inform them about the risks, what are the best methods to convince them to act?
Prompt initial communications and providing opportunities for individual discussions with our technical experts and/or regulators. We have utilized letters, flyers, door-to-door meetings, public meetings and Open-house format meetings. The open-house format has worked well when dealing with a large group of affected property owners since it allows for formal presentation of information, through the use of posters and flyers, to be coupled with opportunities for one-on-one meetings with technical, regulatory or health officials.
JRCC: Do you have any practical example to tell us going through all stages, from the detection of a risk, to make it public, to convince to do something about it, to fix it ?
I have attached a project description for a recent project we performed, where a Vapor Intrusion issue was encountered at a public school located adjacent to my client's site.
JRCC: Any experience of a crisis?
So far, I wouldn't categorize any of our experiences as crises, although the provided case study was intense. For our typical situations, I would define a crisis as a lawsuit for my client. The contaminants we commonly deal with (TCE and PCE) are usually found at long-term, chronic exposure levels. As such, exposure crisis is not common. I would state that a recent addendum to the toxicological profile for TCE, from the Agency for Toxic Substance and Disease Registry (ASTDR), has prompted some concern related to the inhalation exposure of low levels of TCE for pregnant women. I have worked on a site where State environmental and Health officials reacted to this information and recommended to a pregnant woman that she relocate until the exposure risk could be mitigated. While not truly a crisis, it comes close for the affected individual and my client.
JRCC: What is your risk and crisis philosophy?
It is my experience that the best overall results for the exposed parties and the responsible party are obtained by remaining proactive and transparent during the entire process. This approach minimizes risk to potentially exposed parties by providing accurate and timely information as soon as it is available. This approach also minimizes liability risk for my clients, the responsible party, who are reacting to potential health concerns as soon as they are aware, and are not perceived by individuals or the media as being calculating, evasive or strategic in their response.
JRCC: What is the added value of your company's approach?
There are many effective environmental consultants in the industry who may be capable of providing the necessary subsurface investigation and remediation services. EnviroForensics pairs the technical expertise of our geologists, engineers and scientists with our experience and specialization in VI assessments and risk communication. Since Vapor Intrusion is only recently such a large concern in much of the States, many responsible parties with sites contaminated by chlorinated compounds may be missing these vital components.
JRCC: Where is your company going to be in 3, 5 or 10 years from now?
Jeff Carnahan: EnviroForensics has experienced sustained growth over the past 3-5 years. As we have assisted many clients with complicated VI and risk communication issues in recent years, the number of responsible parties who recognize that they need our services continues to increase. We continue to strategically hire the best technical personnel and are laying the corporate infrastructure to maintain this growth through the next decade.
JRCC: Thank you, Jeff Carnahan, for this interview.