As illustrated by the recent actions taken by the DEP, there is increasing concern related to public health around the issue of Vapor Intrusion (VI) at Sites impacted by VOCs and in particular trichloroethylene (TCE).
Disposal Sites contaminated with TCE are challenging to assess and fully remediate, particularly in the heavily developed Northeast Region of Massachusetts. The release of TCE to groundwater can cause contaminants to migrate away from the source, which may result in impacts to multiple properties and buildings. With the revised standards promulgated by the Mass DEP, it is even more important to implement robust Response Actions to adequately assess the extent of potential impacts and then design a remedial plan to mitigate those impacts. Commonly used mitigation methods include the installation of vapor barriers in conjunction with a sub-slab depressurization system to divert vapors away from occupied buildings and spaces.
However, in light of the lower standards and potential human health effects, the implementation of contaminant source reduction, in the form of soil removal or groundwater treatment for example, may become a more commonly used measure to reduce exposure at TCE Disposal Sites. Regardless of the approach to remediate a Disposal Site, when the bar for cleanup is lowered, the result will very likely increase the time, effort and thereby costs needed to achieve site closure.
What does the Foley Hoag LLP - Environmental Law posting mean for your due diligence projects?
The rules for chlorinated solvents have changed. This means that your next Phase I ESA may have different findings than those in previous assessments. The most recent updates to the ASTM standard (ASTM E 1527-13) included vapor intrusion guidance. This was an industry response to increasing regulatory concerns about vapor intrusion, like the example presented in the Foley Hoag LLP posting. Chlorinated solvents are common environmental contaminants and they have significant potential to cause vapor intrusion issues. As a result, both on-site and off-site releases of chlorinated solvents are under greater scrutiny and even release sites that were previously considered "closed" may now be considered a significant environmental risk.
What are chlorinated solvents?
Common chlorinated solvents are effective degreasing agents that were commonly used in dry cleaning, auto repair, and manufacturing facilities. Some industries have begun to phase out chlorinated solvents, but they are still commonly used throughout the country. Common environmental contaminants include Tetrachloroethene (PCE) and tricholoroethene (TCE), as well as breakdown products dichloroethene (DCE) and vinyl chloride (VC). Exposure to these contaminants can result in toxic health effects, which is why MA DEP lowered the acceptable level of these compounds in the environment.
What can you do about a chlorinated solvent release?
The good news is that there are many avenues to resolve a chlorinated solvent release depending on the magnitude, type of property, and type of environmental impacts (i.e. soil, groundwater, soil vapor). A chlorinated solvent release should not be considered a deal breaker. It is just one more step in the due diligence process. EBI Consulting is an industry leader in recognizing environmental issues and finding cost effective solutions to minimize risk.
Thanks to EBI Consulting's Sean Dunn and Matt Wilson for their insight on The Massachusetts Department of Environmental Protection's Waste Site Cleanup Advisory Committee's recent announcement!