Category: Vapor Intrusion

Often times, environmental consultants encounter manmade structures during environmental investigations which can serve as preferential pathways for the migration of vapor phase contaminants.  Sewer lines are common preferential pathways and are usually investigated during vapor intrusion assessments to determine whether offsite properties are at risk of exposure.  Sewers are present at various depths and constructed of different materials, including clay tile, reinforced concrete, and PVC, depending on the timeframe during which they were installed.  Great care must be taken when accessing the sewer lines to make sure that they, along with any other utilities in the area, are not damaged.  Hand augers are typically used to access utilities because the use of heavy drilling equipment results in a higher potential for damage.

Recently, EnviroForensics completed a preferential pathway investigation near an active dry cleaning facility to determine the extent to which the sewer line serving the property may be acting as a preferential pathway.  This Site presented a unique challenge since the sewers are buried 15 feet below ground under a hard clay material, making them difficult to access with a hand auger.  In order to overcome the challenge, EnviroForensics elected to make use of hydro excavating equipment during the installation of soil gas sampling implants.  Hydro excavation makes use of high-pressure water to break away soil and a vacuum is then used to remove the soil and water from the cavity.  Since the water pressure is not great enough to damage the sewer materials themselves, it is possible to safely expose the utilities for inspection and investigation.

Steel soil gas sampling implants were installed within the fill material surrounding the sewer, allowing EnviroForensics staff to collect samples of the subsurface vapor that may be migrating to offsite properties.  The use of hydro excavating equipment proved to be both efficient and effective, allowing for the installation of three soil gas points in a timely fashion while causing minimal disturbance to the surrounding properties, and ongoing business operations at the dry cleaners.

EnviroForensics is committed to utilizing the most effective techniques and technology to ensure each investigation is conducted as thoroughly as possible. Our team of experts are experienced in locating the source of contamination and creating remediation plans that accurately address and clean up any contamination on our clients’ properties. Additionally, we are equipped with a team of Vapor Intrusion (VI) experts who are known within the VI assessment community and are being sought out specifically to evaluate the VI exposure pathway.

At EnviroForensics, we know that dealing with contamination at your site of business can be overwhelming, burdensome and expensive. We work to eliminate these concerns by accurately addressing contamination while searching for alternative means of funding—such as historical insurance policies—that will significantly reduce your out-of-pockets costs. Our clients are our priority, and we are committed to turning your environmental liabilities into assets.

---

About the Authors

Matthew Bono
Project Manager
866.888.7911
mbono@enviroforensics.com

Mr. Bono has over 3 years of professional experience in environmental consulting. He has been involved in subsurface investigations and remediation activities at facilities and properties impacted with chlorinated solvents, petroleum products, and other hydrocarbons throughout the state of Indiana. Matt has assisted with data evaluation and reporting on all phases of projects from investigations through closure and has provided project management services including work scope development, budget management, and personnel management. He has provided oversight during remedial plan implementation, incorporating multiple technological approaches including pump and treat systems, soil vapor extraction (SVE), enhanced anaerobic bioremediation, thermal desorption, and soil excavation. Matt also has experience in contaminant transport and groundwater flow modeling. He has worked closely with clients and subcontractors, as well as state and federal regulators.

William Garnes
Field Geologist
wgarnes@enviroforensics.com

Correctly assessing the Vapor Intrusion (VI) exposure pathway is a complex process, which is rarely straight forward. When VI does occur at or near hazardous material cleanup sites, it rarely results in a constant stream of contaminants into the breathing zone.  Rather, there are many variables that affect the way vapors move from the subsurface into a structure.  Daily and seasonal temperature fluctuations result in variable pressures within and beneath buildings that change VI conditions. The amount of precipitation that falls also affects vapor intrusion rates, and can at times temporarily stop it altogether.  Building foundation and construction details can affect the pathway that intruding vapors may take once beneath or inside a structure, thereby resulting in a distribution of indoor air contaminants that aren’t intuitively consistent with predictive VI rules of thumb. Complicating things even more is the fact that numerous household products contain the same chemicals that we are trying to assess from below ground contamination.  Taking into account all of these variables to determine if a human inhalation exposure is in existence, or may be in existence at some time during the year, is a highly detailed and specialized process.

Fortunately, the VI team at EnviroForensics maintains a line of highly specialized, field-based, analytical instrumentation that can be used to tease out the necessary details during VI assessments. One of the most highly developed instruments in our arsenal is a portable Gas Chromatograph/Mass Spectrometer, named HAPSITE. The HAPSITE was originally designed by its manufacturer for the U.S. Military and is designed to deliver real time qualitative and quantitative, laboratory-quality results for air samples in the field. The HAPSITE has the capability of identifying and measuring specific volatile organic compounds as low as the parts per trillion (ppt) range. The HAPSITE instrument can be calibrated to measure the ions specific to the contaminants of concern (COCs) at the Site.

The Enviroforensics VI team consists of a certified HAPSITE operator. When operated in ‘survey’ mode, the HAPSITE instrument provides real-time data, depicted as an on-going line graph on the front panel display of the instrument.  We use this survey mode during VI assessments to find specific points in a structure where vapors may be entering the indoor air. We have found that cracks in floors and walls, floor drains, pipe chases, interior wall spaces and attics are all important features to explore. Background sources, such as those common household products mentioned earlier, can also be found hiding in closets, drawers, basement corners, etc. When an area of concern is located, the HAPSITE is switched to ‘run’ mode. This sampling mode collects an air sample that is analyzed by the instrument with laboratory quality, in a short period of time.  This type of real-time analysis allows for adjustments to be made in the field and provides comprehensive conclusions with fewer mobilizations and sampling events.

During any VI assessment, the main line of regulatory thought is that if VI is occurring at any time during the day or year, that worst case exposure condition is used to calculate the occupant’s potential risk. By using highly-specialized instrumentation, such as the HAPSITE, the EnviroForensics VI team greatly improves the odds that we can interpret all of the variables that are part of VI assessments and properly report true exposure conditions.

---

About the Authors:

Megan Hamilton
Risk Assessor and Vapor Intrusion Specialist

866-888-7911
mhamilton@enviroforensics.com

Ms. Hamilton has over fifteen years of experience in environmental regulatory oversight and consulting, with a focus on risk assessment and vapor intrusion expertise. Her diversified professional experience includes research, policy development, technical writing, public outreach, vapor intrusion investigation and remediation, data analysis and interpretation, human health risk assessment, and conceptual site model analysis. Ms. Hamilton served as a technical, scientific, and risk assessment policy resource for the Indiana Department of Environmental Management’s (IDEM) Office of Land Quality for nine years. She also served as the coordinator and team leader for the IDEM Vapor Intrusion Workgroup for six years and is the main author of the current Indiana Vapor Intrusion Guidance. She has helped design and implement numerous vapor intrusion investigations for chlorinated and petroleum contaminated sites throughout Indiana.  Ms. Hamilton is experienced in evaluating human health risk assessments, as well as vapor intrusion risk assessments for sites regulated by all of IDEM’s remediation programs, including:

• Brownfields Program
• Leaking Underground Storage Tank Program
• RCRA Program
• State Cleanup Program
• Voluntary Remediation Program

Ms. Hamilton develops, helps implement, and oversees the VI investigations and mitigation for all of EnviroForensic’s projects. She is also the main contact for risk communication issues and community outreach development. Ms. Hamilton has presented at several National Conferences, is a member of the National EPA VI Science Advisory Committee, and currently serves on the Board of Directors for the Midwestern States Environmental Consultants Association (MSECA).

Jeff Carnahan, L.P.G.
Vice President, Chief Technical Officer

866-888-7911
jcarnahan@enviroforensics.com

Jeff Carnahan is a Licensed Professional Geologist (LPG) with over 17 years of environmental consulting and remediation experience.  Mr. Carnahan’s 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.  While managing sites ranging in size from retail gas stations and dry cleaners to large manufacturing facilities, Mr. Carnahan 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 Mr. Carnahan has provided technical support to the legal community regarding the cause, origin, transport and potential cost of environmental releases. Additionally, Mr. Carnahan has over 13 years of experience in the investigation and mitigation of vapor intrusion issues and leads the VI Assessment Team at EnviroForensics. His experience and insight make Mr. Carnahan uniquely qualified to advise his clients on potential environmental liability issues and cost implications.

 

 

 

 

Most people who reside in industrialized countries are well aware that our collective, historical pursuit of a higher standard of living has created an environmental pollution problem that threatens the very lives we originally intended to enrich.  Ironically, our successes in these endeavors have also allowed for advances in science and medicine, which have revealed the harms of the pollution.  I’ve worked in the environmental investigation and remediation industry for nearly two decades now; this business has been wrought by such irony.

In many cases, those legally responsible for environmental contamination were innocent of malicious intent when the release occurred.  They were only guilty of not knowing that the chemicals or processes they employed during their daily pursuit of making a living were causing environmental damage, and even direct risks to human health.  If I’ve heard the story once, I’ve heard it a hundred times; “We were just doing things as everyone else did them back then…we had no idea that our business operations were harming the environment, and for goodness sake, we would never have done anything to hurt anyone on purpose.”  Small business operators and large manufacturing facility employees alike have often expressed this sentiment when alerted to the resulting harm, and at times, their realization has led to real tears of shame and remorse.  Yesterday these folks were going about their businesses and their lives without the knowledge that they may be facing huge, potentially insurmountable legal and financial burdens.  Today they are responsible for setting things right.  It’s tempting to demonize “polluters” in our current society, especially given the intentional bad environmental decisions made by some.  I choose to believe; however, that the merit of actions taken by those responsible after they learn of causing contamination is truly the article to be judged.

With the advent of environmental regulations in the late 20th Century, the United States established by law a system for controlling hazardous waste from the time it is generated until its ultimate disposal, known as the “cradle to grave” scenario.  A chain of legal responsibility resulted, which linked the person or entity that caused pollution to the current owner of the pollution, or the real estate within which the hazardous waste (i.e. pollution) resides.  These regulatory activities were performed in the pursuit of assigning financial responsibility for conducting cleanup to stop unacceptable human and ecological exposure to toxic materials.  Those persons or entities who are presently at the front of the succession of liability line are referred to as the responsible parties, or RPs.

Responsible Parties can be billion dollar corporations, small businesses, retirees, or even national governments (i.e. military bases, energy research facilities).  In some cases, the entity that created the hazardous waste is still operating and able to take control of their duty to manage or dispose of it properly.  In other scenarios, the generator of the waste is no longer in business or has moved on to different locations without the knowledge that hazardous waste they created had been released into the subsurface.  In the latter scenario, the liability to manage the contamination may have been accidently inherited by the unwitting purchaser of the property that was polluted by someone else’s hazardous waste.

Once environmental contamination and a RP has been identified by a governmental environmental agency, or an affected third-party, they will most likely enforce the existing laws, or file a lawsuit, and require that the RP investigate and clean up the mess.  This is typically regardless of whether the legally responsible entity caused the contamination or not.  Assuming that the RP has the financial means to take care of the problem, they will set forth their efforts at removing the pollution to the extent possible.  Even with our great advances in science and engineering, the full extraction or destruction of every molecule of hazardous waste that may be in contaminated soils, rock and groundwater is simply not practical.  Environmental regulators, attorneys and scientists understand that this limitation exists; and therefore, the success of cleanup projects is most often measured by the ability to eliminate adverse human health effects of exposure to the remaining residual hazardous waste.  Contaminated properties are many times closed with a commitment by the RP to monitor future land usage at the contaminated property and ensure that no one becomes exposed.  The regulating agencies have termed this process, “Long-Term Stewardship,” or LTS.

The legal and financial practicality of conducting and regulating the seemingly endless process of LTS is being fiercely debated in Washington D.C. at present; as the White House Office of Management and Budget (OMB) evaluates the final draft of EPA’s Vapor Intrusion Guidance, which contains the latest rendition of LTS requirements.  Federally led environmental cleanup programs under CERCLA (Superfund) and RCRA have had LTS requirements for decades.  These programs have been used as the basis for the new LTS requirements that are also likely to be applied through state led programs.

It is logical to presume that those responsible for environmental releases should also be those upon whom we all rely on to make pollution problems right.  Individuals whose health has been harmed, or whose property has been impacted by environmental releases from others certainly have a right to seek answers and restitution from the responsible parties.  Society as a whole has benefitted from the production of goods that resulted in contamination as a consequence.  It may be appropriate; therefore, to keep sight of intent when considering the punitive component of damages sought.  We all expect, and need responsible parties to use their financial assets to pay for the investigation and cleanup of the mess that they or their corporate predecessors created.  With new LTS requirements, they will also be our environmental stewards, keeping an eye on residual contamination and exposure into the future for generations to come.

 

---

About the author:
Environmental Expert

Jeff Carnahan, L.P.G.
866-888-7911
jcarnahan@enviroforensics.com

Jeffrey Carnahan is a Vice President and the Director of Technical Services at EnviroForensics, Mr. Carnahan holds a M.S. in Geology and is a Licensed Professional Geologist (LPG) with 17 years of environmental consulting and remediation experience.  Mr. Carnahan’s 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.  While managing sites ranging in size from retail gas stations and dry cleaners to large manufacturing facilities, Mr. Carnahan 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.  In his role as Director of Technical Services, Mr. Carnahan leads, supports and encourages the entire EnviroForensics team of experts as they guide their clients through the process of turning environmental liabilities to assets.

---

EnviroForensics is an environmental engineering firm specializing in soil and groundwater investigation and remediation and vapor intrusion assessment and mitigation. EnviroForensics has all have the tools available to us to perform the highest caliber science in the market today, which allows designing and implementing clever, innovative and effective solutions to PCE and TCE contamination. EnviroForensics® has pioneered and perfected the utilization of Comprehensive General Liability insurance policies as a resource to pay for the high costs associated with soil and groundwater investigations, remediations, and legal defense. 

Written by Stephen R. Henshaw, President & CEO, EnviroForensics

As seen in the December 2014 issue of Cleaner & Launderer

PDF Version

The latest wrinkle in the cleanup process of sites contaminated with chlorinated solvents (PCE and TCE) is in understanding how long the site, and those sites downgradient, will need to be monitored when complete contaminant removal is not possible and potential human exposure remains. Generally speaking, the more contamination left in place, the longer the site will need to be monitored. I want to tell you this because the cleanup costs that will be generated for your site, will be greatly affected by two things; 1) the removal of contaminated soil and groundwater in the source area and 2) the long-term monitoring requirements (how many locations need to be monitored and for how long). If you are not aware of these two big issues, you are not looking at the full picture and you could be unwittingly reviewing cleanup cost estimates that may have been prepared using the old “bait and switch”.

Let me make no bones about it, the environmental consulting industry is highly competitive and like many purchases consumers make, price is a large factor when you select a consultant to clean up environmental contamination. Nowhere is this price more susceptible to variation than in asking for the consultant to give a true site closure cost estimate. The most important thing to understand about what I am telling you is that you know to ask the hard questions about the provided cost to closure and don’t get caught up in hearing what you want to hear. Consultants don’t enjoy being the bearer of bad news and they realize that they might be competitively shopped, especially if the provided costs are higher than the party paying for the contamination expects. Consequently, the consultant may try to soft pedal the remediation costs. I refer to this as, “telling people what they want to hear”. I see this all the time, particularly when insurance companies are responsible for paying for the cleanup. Continue reading “Long-term Stewardship of Contaminated Sites, Vapor Intrusion Mitigation and Monitoring Fit the Requirements”