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MDEQ rescinds vapor intrusion guidance – uncertainty reigns – what is clean enough?

21 Jun 2017

Back in the 1990’s, there was uncertainty about when a cleanup was truly completed – “how clean is clean?” was the question and it seems that those days may be returning – at least for a while.

The MDEQ announced Tuesday that it was rescinding major parts of its May 2013 Vapor Intrusion Guidance which we blogged about when it was published.  This 2013 guidance addressed part of the question of how clean is “clean enough” when a brownfield redevelopment or cleanup does not reduce the residual contamination to zero.  Vapor intrusion is explained in this link but, basically, it is the threat that some contaminants may migrate upward from soils and groundwater into buildings at unsafe levels.  For the last four years, people in Michigan have relied on and been guided by the 2013 Guidance.

MDEQ has been trying for years to update its clean up rules and standards which have been in place for some 15 years.  The thought was that new data and studies were available and the cleanup standards which were largely driven by conservative assumptions should be brought up to date.  Due to somewhat arcane legal reasons, MDEQ set October 27, 2017, as its date for promulgating these new rules and have been working hard (and continues to work  hard) to meet this deadline (the most current version available at the moment can be found here but updates are expected soon).

Review your BEA or due care plan (if you have one); if your site doesn’t have volatile compounds – rest easier. If it does, your BEA might be subject to an EPA evaluation if there is a concern about vapors migrating into occupied spaces – even off-site spaces. 

Until MDEQ adopts its new rules, MDEQ will include a standard caveat in approval letters issued moving forward that screening levels used “may not reflect the best available science.” That level of uncertainty may chill many deals and plans under consideration or drive them to more expensive cleanups.    

Logically,  MDEQ argues that they should similarly update the vapor intrusion standards and include them in the rules package.  Vapor intrusion has been in the press a lot recently including this article that discusses 4,000 sites which the State might be looking to address an issue which was thought put to bed or wasn’t simply an issue when the site was granted closed status.

This is where the uncertainty kicks in.  MDEQ doesn’t typically address direct human health threats – that would be the State Health Department.  The same State Health Department that allegedly missed the Flint Water Crisis and whose director and chief medical officer have been indicted. The State Health Department takes a fairly conservative approach to vapor intrusion and has told MDEQ that its standards are too lenient.  MDEQ has developed new hyper-conservative standards that could cause sites which previously passed to now fail.

What is a property owner/developer to do?  First, review your BEA and due care plan (if you have one); if your site doesn’t have volatile compounds – rest easier.  If it does, it is possible your property might be subject to EPA action if there is a concern about vapors migrating into occupied spaces – particularly off-site spaces.  The owner of the site profiled in the MiLive article above found their BEA protection weaker than they had thought and are now dealing with an EPA demand for payment.

For future deals, buyers and lenders may want more aggressive due diligence and cleanup programs to ensure that vapor intrusion is not a risk. This may sideline properties which, until recently would’ve been accepted using the MDEQ’s 2013 Guidance.

Until MDEQ adopts its new rules (which may not take effect until next Spring), the MDEQ will be reviewing and approving requests to approve “no further action” based on current standards but MDEQ will include a standard caveat in approval letters issued moving forward that screening levels used “may not reflect the best available science.”   That level of uncertainty may chill many deals and plans under consideration or drive them to more expensive cleanups or site-specific cleanups which require far more and expensive justification.