What’s the Stink about Vapor Intrusion?

The new vapor intrusion regulations in Illinois officially became effective on July 15, 2013.  These regulations now require the assessment of the “indoor inhalation pathway” (aka vapor intrusion) in addition to the existing pathways that have always been a part of the State’s risk-based approach to closure known as TACO (Tiered Approach to Corrective Action Objectives-35 IAC Part 742).  Over the last year, the new IEPA regulations have shed some light on the vapor intrusion issue, however, as with any new set of regulatory requirements, the State regulators and the marketplace are still feeling their way around the subject.  Based on our experience to date, one thing that is clear is the need to better educate the real estate community on how best to handle potential vapor intrusion risks.

Vapor intrusion occurs when volatile chemicals migrating from contaminated soil and/or groundwater (through processes called advection and/or diffusion) make their way into the indoor air spaces of overlying buildings.  Prior to July 2013, it was common practice to use building slabs as engineered barriers to prevent exposure to underlying contamination, including impacts from volatile chemicals, as a means of complying with the State’s TACO regulations in effect at that time.  The IEPA issued more than 3,500 No Further Remediation (NFR) letters pursuant to the TACO regulations since the program’s inception.

Due to the human health risks and liability related to indoor air quality issues, vapor intrusion has become a significant concern for both owners and potential purchasers of commercial properties, and for lenders and other financial partners involved in commercial real estate  transactions.  With the recent implementation of the new State regulations and publication of new industry standards (ASTM) specific to this issue, Pioneer has seen firsthand how vapor intrusion has permeated the real estate transactional market.

One of the most common situations that arises involves the buying, selling or refinancing of debt on properties with previously-existing NFR letters where volatile contamination was allowed to remain on site.  Whereas before the NFR letter was seen as the final solution to a site’s environmental issues, now owners or prospective purchasers of those sites are forced to consider potential vapor intrusion concerns as part of their due diligence or overall risk evaluation.  We see this situation on sites as commonplace as strip malls with current or former dry cleaning tenants to auto repair and small manufacturing businesses that utilized chlorinated (or petroleum-based) solvents in their daily operations.  And it has added a new layer to the traditional soil/groundwater testing usually conducted as part of Phase II Environmental Site Assessments – the testing of soil gas to evaluate the vapor intrusion pathway. Whether the Phase II is conducted during due diligence or for purposes of regulatory closure, soil gas testing has become an integral part of the overall process of site characterization.

So what if volatile chemicals are found below an existing building or in the area of a future structure to be built as part of a planned redevelopment?  Vapor mitigation, or the removal of contaminated vapors from beneath the floor slabs of buildings, is one solution implemented by Pioneer in response to volatile contamination below structures.  The new State regulations specifically identify four vapor mitigation systems that are considered acceptable by default.  The use of sub-slab depressurization systems (SSD) has long been an effective remedy in the radon industry and is well-suited to existing structures. Membrane barrier systems are also very effective and a relatively low cost fix when integrated into the new construction of buildings.  These are two of the default systems allowed by the IEPA that Pioneer has successfully installed at various sites, however, we believe innovation and technology advancements will produce many more viable options as the industry evolves.

Pioneer is extremely knowledgeable of the assessment techniques and mitigation strategies utilized to address the vapor intrusion issue, and although they may be subject to revision, Pioneer is constantly adapting to the updated requirements in order to best serve our clients.  Pioneer educates our clients on this evolving issue which has now become a standard part of the due diligence process.  We provide thorough vapor intrusion evaluations in order to better assess the environmental condition of a property and allow our clients to make an informed decision on how best to solve the problem at their facility and enable them to proceed with a sale, purchase, or loan on commercial real estate even when vapor intrusion is a concern.

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