Whether we agreed with it or not, it seemed like there was a process in Michigan to evaluate the vapor intrusion pathway under Part 201 of the Natural Resources and Environmental Protection Act (NREPA) at sites with releases of volatile chemicals. However, just when we thought that the vapor intrusion screening levels (VISLs) presented in the Michigan Department of Environmental Quality (MDEQ) Guidance Document for the Vapor Intrusion Pathway, dated May 2013, were relatively set, the MDEQ announced their decision to rescind them.
Michigan’s Cleanup Criteria Later This Year?
As if this is not problematic enough, the MDEQ is in the “middle” (or nearing the “end,” depending upon with whom you speak) of trying to promulgate updated Part 201 regulations and associated screening levels and cleanup criteria. The proposed criteria/screening levels for a number of “common contaminants” (e.g., TCE, PCE) will be lower (in some instances significantly lower) than current or currently-rescinded levels. We may see these come to fruition in the fall of 2017…or not.
The current lack of “vapor intrusion certainty” in Michigan is resulting in some regulatory conflicts (Photo Credit: Dragun Corporation).
One more (at least) complicating factor is the “information sharing” between the MDEQ and the Department of Health and Human Services (DHHS). The MDEQ has provided site information regarding volatile chemicals in soil, groundwater, and vapor to DHHS, and they have gone into properties and mandated building evacuations and vapor mitigations (see “Poison vapor evacuations increase as old chemical threats resurface”). However, DHHS plays by a different set of rules and screening levels than the MDEQ. So what’s “good” for the MDEQ under Part 201 (especially now) is not necessarily “good” for DHHS. Inasmuch as businesses cannot sit by and wait for final regulatory decisions to be negotiated, the question is, what should you do in the meantime?
What Should You Do?
This is a good question and a somewhat complicated one. It should be discussed with both legal and technical advisors. It will, ultimately, depend upon your goal (e.g., Baseline Environmental Assessments [BEAs], Due Care, No Further Action, etc.). In this time of flux, there are a few options.
- Wait it out. If time is on your side, sit back and see where the chips fall and there is more regulatory certainty. During this time, stay active in your trade organizations, and provide input on your position about this topic.
- Use the current Part 201 criteria (i.e., soil and groundwater volatilization to indoor air inhalation criteria [SVIIC and GVIIC]). For example, based on our discussions with MDEQ personnel, the MDEQ is currently accepting submittals (i.e., BEAs) that rely upon the current criteria. However, the MDEQ states that there will be a caveat to the “approval” that this may not meet the new criteria coming down the road and, as such, may require additional evaluation when the new Part 201 rules become effective.
- Develop site-specific criteria. Note that this will require additional site data than what is often collected during typical investigations.
- Use the US Environmental Protection Agency (EPA) screening levels.
- Apply the screening levels used by DHHS.
Each of these options has pros and cons and there is no “one size fits all.” Every site is different and requires thorough discussion prior to selection. One thing about vapor intrusion in Michigan is certain, and that is uncertainty (Note: for a primer on VI, see our Vapor Intrusion Video).
If you have questions or comments, please feel free to contact me at 248-932-0228, ext. 125.