Presentation Transcript

1. What you don’t know WILL hurt you.
2. Today’s presenters: James D. Okun, Principal Kevin J. O’Reilly, Principal
3. What we will cover today Why learning about Vapor Intrusion (VI) is important; Back ground – What is Vapor Intrusion; What MassDEP is doing with VI; and A case study illustrating some of the problems at VI sites.
4. If you own, operate or accept property as collateral, vapor intrusion may be your most important environmental risk. Why Should you be Concerned? An ASTM environmental site assessment offers protection from federal CERCLA liability, but in practice CERCLA liability is relatively uncommon. VI risk is far more common, but a standard Phase I ESA will not necessarily identify potential VI problems.
5. What Happens when VI is Discovered? The response from state regulators can vary from requiring more testing to insisting that occupancy of the building be suddenly discontinued. The regulators have broad latitude in these situations.
6. Vapor intrusion is what happens when volatile chemicals in the ground migrate up and into overlying buildings. Once in the buildings, these chemicals get into the air that people breath. It is one of the most serious ways that people can be exposed to hazardous chemicals. So what is Vapor Intrusion?
7. Was Vapor Intrusion Just Recently Discovered? No, MassDEP was among the first environmental agencies in the nation concerned about VI back in 1993 when the current cleanup law was first enacted. At that time scientific thinking was that VI was uncommon, occurring only rarely. Newer studies prove that this view was mistaken. VI is now understood to be more common and potentially serious.
8. Why Haven’t I Heard about VI? It is only in the past few years that environmental scientists realized the models they were using significantly under-predicted the VI problems. Information about the new analysis of VI is just getting through to the real estate community now.
9. Yes, radon acts by the same mechanisms as does VI. VI and radon are invisible, have no odor and require technical tests to be detected. Is VI Similar to Radon Gas?
10. Radon and VI occur when there is a source in the ground; A preferential pathway that channels to radon or VOCs from the source location to beneath a building; and A driving force that draws the radon or VOCs into the indoor air of a building. Radon and Vapor Intrusion
11. Is VI just a Theory or is it Real? Hard to believe the first time you hear about it, but it’s definitely real. Soil particles only take up 60-70% of a volume of soil, the rest is gas. These void spaces permit the movement of chemical vapors.
12. Do Radon and VOCs go Through Concrete? When we look at concrete, we see an impermeable material. But at the molecular level, where gasses operate, it looks like a bunch of connected caverns that let gasses pass through easily.
13. What is Vapor Intrusion?
14. Gasoline Petroleum Naphtha Mineral Spirits Dry Cleaning Solvent. Among these the most notorious is dry cleaning solvents, usually perchloroethylene. What Contaminants cause VI?
15. If I know My Property is Clean, do I Still Need to Worry about VI? Unfortunately, you do. Some chemicals move underground as much as a half mile from the disposal area to cause a VI problem. While a half mile movement of a VI issue is unusual, migration of a few hundred feet is not. In an urban environment, VI problems can be common.
16. Why is indoor air testing an unreliable approach to VI testing? People intuitively think indoor air testing is a good way to assess VI problems. Indoor air testing is actually an unreliable approach because it is prone to false readings. For instance alcohol, fingernail polish, smoke, cleaners and paints That’s because there are other sources of VOCs in buildings and daily conditions can affect results positively or negatively.
17. Best Testing Approach Ideally, a sample of soil gas is collected from beneath the floor slab of the building. To do this a small hole is drilled through the floor and sample equipment is installed. The sample is carefully withdrawn from beneath the floor, collected in a special canister and delivered to a laboratory for chemical analysis. The lab is able to detect very low concentrations in the air sample.
18. What Happens to a VI Property? In Massachusetts, VI is what I call the roach motel of environmental regulation; you can check in, but you can never check out. Under the current regulations, once a property is tagged as having a VI problem, achieving a “permanent solution” status can be impossible.
19. For the past few years, vapor intrusion has been the number one issue being addressed by MassDEP. Recent Regulatory Response Starting in 2007, MassDEP initiated an unprecedented re-evaluation of over 600 site closures and required new response actions at over 100 of them due to concerns about the possibility of vapor intrusion.
20. Even in cases where there is no evidence that VI is taking place – that is there are no VOCs in indoor air – MassDEP will still require a Notice of Activity and Use Limitation (a deed notice) if groundwater VOC concentrations exceed the GW-2 standards. This requirement is to address the possibility that a future building may not be as effective as the current building at minimizing potential VI impacts. This is a controversial requirement because it is based on the occurrence of a possible future problem. AULs are expensive to prepare, and in the past have been audit magnets. Groundwater and AULs
21. DEP has been struggling to come up with a regulatory approach to VI for over 3 years. There were two major draft guidance documents issued before they realized new regulations would be needed in addition to thick guidance documents. As of now, it looks as if any property with a theoretical risk of VI occurring, whether it is actually occurring or not, will be required to have an AUL as a matter of regulation, not just guidance. What is MassDEP up to Now?
22. DEP has a very full plate of regulation changes slated for the waste site cleanup program. Over the next few months they will be floating draft versions of many proposed regulation changes. Their ambitious goal is to have the changes in-place by July 1, 2012. At which time we may need to have another breakfast seminar! Look for More Regulatory Changes FIN
23. Quick Case Study Dry Cleaner
24. Interim Final Vapor Intrusion Guidance Document (MassDEP)
25. December 2011 MassDEP Guidance Summary Fig 2-1 Basic elements of the vapor intrusion pathway
26. December 2011 MassDEP Guidance Summary Figure 1-1: Evaluation of vapor intrusion potential at sites where VOCs have been released to the environment.
27. December 2011 MassDEP Guidance Summary Multiple Lines of Evidence Multiple Phases (soil, groundwater, air, product) Multiple Sampling Locations Multiple Rounds
28. PCE aka – perchloroethylene, tetrachloroethylene Dry Cleaning Solvent
29. Water: ug/liter ~ ppb Air/Soil Gas: ug/cubic meter ≠ ppb Units
30. OSHA Ceiling Concentrations 200,000 ug/cubic meter PCE
31. MassDEP “No Significant Risk” Estimate Residential: 2.3 ug/cubic meter Commercial: 13 ug/cubic meter PCE
32. PCE MassDEP “Imminent Hazard” Estimate Residential: 14 ug/cubic meter Commercial: 50 ug/cubic meter
33. Q & A