Long-term Stewardship of Contaminated Sites, Vapor Intrusion Mitigation and Monitoring Fit the Requirements

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

As seen in the December 2014 issue of Cleaner & Launderer

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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”

Vapor Intrusion or Process Emissions – Help Me, Help You

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

As seen in the August 2014 issue of Cleaner & Launderer

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I’ve talked a lot about vapor intrusion over the past few years. Vapor intrusion occurs when volatile organic compounds (VOCs) in soil and groundwater off-gas and migrate into occupied buildings and store fronts. The need to conduct vapor intrusion sampling is often times the result of VOCs in the soil and groundwater. Typically a vapor intrusion assessment will include collecting sub-slab soil gas samples along with the collection of indoor air samples. This paired sampling, as it is often times referred to, is designed to show two things: 1) whether or not there is contamination in the subsurface soil gas sample that could create a vapor intrusion issue; and 2) whether or not there are concentrations of VOCs in the breathing air that could be attributable to the subsurface contamination.

I want to tell you this because if it is determined that vapor intrusion exists and VOCs are migrating from the subsurface into occupied building structures, you as the responsible party for the subsurface impacts, would also be responsible for mitigating those vapors. Additionally, the identification of a vapor intrusion issue in buildings not owned by you could lead to the potential for third party litigation should it be determined that people have been breathing contaminated air. Continue reading “Vapor Intrusion or Process Emissions – Help Me, Help You”

Practical Approaches for Remediation of VOCs in Clayey Soils

Written by Stephen R. Henshaw, P.G., President & CEO, EnviroForensics
As seen in the April 2013 issue of Cleaner & Launderer

The question is often posed, “How much will it cost to clean up contamination at a drycleaner?”  Invariably the answer is, it depends.  Factors that come into play include, but are not limited to, the concentration of VOCs present in the subsurface, whether or not the groundwater is impacted, the depth to groundwater, how far the contamination has spread, whether the cleanup will be focused on residential or commercial land use, and the type of geology and stratigraphy underlying the site.  This article focuses on how clayey soils affect cleanup considerations.

Clay is a naturally occurring material composed of very fine-grained particles.  Clayey soil is a term used for soils containing at least 30% clay.  When clay comes in contact with liquids, it swells and becomes plastic.  When it dries out it shrinks and cracks. Clay is very porous and can hold liquids (e.g. water) between the fine-grained particles, but it is not very permeable, meaning liquids won’t move through the material rapidly.  Clayey soils can hold water and moisture, but water does not move through it very fast.  Likewise, air doesn’t move through clayey soils very well.

Continue reading “Practical Approaches for Remediation of VOCs in Clayey Soils”

Vapor Intrusion – What is it and How Can it Effect Me?

Written by Steve Henshaw, P.G., President and CEO of EnviroForensics

As seen in the November 2008 issue of Western Cleaner & Launderer

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What is It?

Vapor intrusion is the migration of volatile chemicals, primarily volatile organic chemicals (VOCs) from the subsurface into overlying buildings. Vapor intrusion requires three components: a source, an inhabited building, and a pathway from the source to the inhabitants.

Over the past few years, vapor intrusion has become a significant environmental issue, one that may have a direct impact on your dry cleaning operation.  In fact, just last spring,  the American Society for Testing and Materials (ASTM), the association responsible for creating the procedures and standards for conducting due diligence for banks lending and financing on real property, has suggested that vapor intrusion issues be considered when loaning on real property.   That is to say, is it likely that vapors are coming off of contaminated soil and groundwater that may migrate underneath buildings and enter basements, crawl spaces and confined spaces and rooms.    Figure 1 is an example of a situation where vapors could enter a commercial or residential building. Continue reading “Vapor Intrusion – What is it and How Can it Effect Me?”

Environmental Corner

Written by Steve Henshaw, P.G., President and CEO, EnviroForensics
As seen in the October 2008 issue of Western Cleaner & Launderer

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Over the past few years, Randy Wendt, the editor of Western Cleaners and Launderers, and I have talked about various environmental issues that threaten the financial viability of operating a dry cleaning business.  Last month Randy asked if I would be willing to prepare periodic articles for this publication focusing on educating dry cleaners about these various issues.  As a staunch supporter of the dry cleaner industry, I am pleased to share my experiences and thoughts with readers, in an effort to demystify the topic of environmental contamination, the process of site investigations, describe different remedial alternatives, and provide insight on ways to protect you from this long tail liability.  I welcome your feedback and topic requests. Continue reading “Environmental Corner”