Cleaning Up Dry Cleaners
Managing Environmental Liability from Dry Cleaner Releases
The management of environmental liability from dry cleaner impacts is a challenging effort for retail properties. The chemical historically used for dry cleaning – tetrachloroethene (often referred to as PCE or “perc”) – is a chlorinated volatile organic compound that has also been used in various industrial operations. Once released, PCE can present long-lasting environmental and human health risks. Replacing dry cleaners that utilize PCE with those using alternative “green” chemicals can prevent future PCE releases, however in many cases the release has already occurred due to years of operations.
To determine a solution for PCE-related challenges, environmental managers must first understand the path it takes once released. Denser than water, PCE released in pure form may sink deep into groundwater. It is soluble enough to dissolve and spread, and volatile enough to represent a vapor intrusion risk to indoor spaces above the plume. PCE may biodegrade into three daughter compounds – including the carcinogen vinyl chloride – before eventually reaching a non-toxic end compound. However, this can only occur if a microbe named Dehalococcoides mccartyi is present, which is not the case for every site. Site characterization can also be complicated, with dry cleaner impacts sometimes traveling along utility laterals or downstream sewer lines rather than remaining beneath the dry cleaner unit itself.
Fortunately there are a number of environmental risk management tools that experienced professionals can deploy to manage risk from dry cleaner impacts, providing solutions to address these often complicated challenges. One option is soil and groundwater remediation, which can limit PCE from migrating off-site and becoming a larger environmental liability. Additionally, indoor air health can be protected through HVAC adjustments, increased ventilation, sealing of preferential pathways, slab fortification, and installation of a vapor mitigation system. Institutional measures can also be implemented to allow PCE to safely remain in the subsurface until it attenuates naturally or can be more easily remediated during a future site redevelopment effort. Langan’s experience with dry cleaner sites includes implementing these solutions, as well as supporting due diligence for property transactions, defining impacts through environmental investigations, managing impacts from previous projects, parsing risks from neighboring properties, and guiding sites to environmental closure of regulatory cases. Langan has deep experience with a range of PCE remediation technologies, as well as the capability to perform treatability studies, pilot tests, and full-scale implementation of those technologies.
Arriving at the ideal management solution requires careful consideration of environmental science, protection of human health, short- and long-term expenses, future plans for the property, and local regulatory environment. Regardless of the solution, understanding a site’s PCE impacts and carefully defining the environmental liability is essential when considering the purchase and/or redevelopment of an affected property. Engaging a team that is knowledgeable and experienced in addressing dry cleaner impacts is a critical step toward developing successful and innovative approaches that combine a careful blend of science and business considerations.