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, last edited January 19, 2012As an instructor for the ASTM E 2600-10 VEC training course, I noticed some confusion over where professional judgment is applied. Should professional judgment be applied when conducting a Tier 1 screen in E 2600-10 so that there are the least number of properties contributing to a vapor encroachment condition and requiring further investigation? Or should professional judgment not be applied in E 2600-10 when deciding whether or not a contaminated property is creating a VEC, but rather be applied in the E 1527-05 Phase I when determining whether this VEC is a REC? My response is that professional judgment can be applied in either place. For example, assume the soil between the target property and a chlorinated solvent-contaminated property located 90 feet down-gradient from a target property is a relatively impermeable silty clay. Under the E 2600-10 Tier 1 screen, this contaminated property would represent a condition that could cause a VEC since the contaminated property is within 100 feet of the target property, and vapors, according to the critical distance definition in E 2600-10, could potentially reach the target property assuming the path of least resistance is in that direction. One approach is to identify the contaminated property in the example as creating a VEC under E 2600-10 since it is within 100 feet of the target property and then, when evaluating if this VEC is also creating a REC in the E 1527-05 Phase I, use the soil characteristics rationale to support your professional opinion that the VEC would not represent a REC. On the other hand, professional judgment can be applied just as well in the E 2600-10 Tier 1 screen to conclude that the down-gradient contaminated property in this example does not represent a VEC because of soil characteristics. In this latter case, the property then need not even be addressed as a potential REC in the Phase I.
The choice as to where professional judgment is better applied remains an open issue, or at least an issue to be dealt with on a case-by-case basis. With respect to my example, an advantage to applying it in the E 2600-10 Tier 1 screen is that it can eliminate a nearby contaminated property that potentially may create a VEC from any further consideration in the Phase I. An advantage to applying it in the Phase I (as part of the REC determination) is that it can simplify E 2600-10 Tier 1 screening.
It would be interesting to hear your rationales for where you would prefer to apply professional judgment with respect to VEC determination in Tier 1 screening under E 2600-10. Would your preference be to eliminate the contaminated property potentially creating a VEC in E 2600-10 Tier 1 screening, or would you prefer to keep it as a VEC and then use professional judgment to eliminate it from further consideration in the REC evaluation in E 1527-05?
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seems to be that the search distances are just presumptive distances and not a "check the box" exercise. An EP cannot ignore conduits or other preferred pathways that might facilitate a VEC. Urban properties can be especially problematic. An EP who does not exercise its professional standard will probably be found to have failed to exercise the minimum standard of care (e.g., committed malpractice).
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Larry - a couple of things:
(1) If a preferential vapor pathway exists from a nearby contaminated property to the target property, Tier 1 screening is not an option. E 2600-10 makes it clear that invasive sampling under Tier 2 (e.g., soil gas sampling) would be necessary to evaluate if vapors have reached the target property. As such, this would not be ignored.
(2) The question is not whether or not professional judgment is applied. It is always applied. The question is where, i.e., in E 2600-10 to eliminate a VEC or in E 1527-05 when the VEC is being evaluated to see if it is a REC. Remember, E 2600-10 is a methodology the EP would use to assess the possible impact of vapor migration in E 1527-05.
(3) As a leading environmental lawyer routinely working with EPs, I would be interested in your opinion regarding the example I posed. Would you prefer the nearby contaminated property not be identified by your EPs as contributing to a VEC (where your EP used professional judgment to conclude this)? Or would you rather have your EP identify it as a VEC and then have the EP use professional judgment later to eliminate it as creating a REC. Note that either way, professional judgment is being applied.
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I usually require VI to be included in a phase 1 and not have a separate E2600 VEC analysis. RECs are still the key outcome for deals. The two-step analysis of VEC to REC generally does not fit into timing for my deals. The only instance when I would see using E2600 for VEC analysis would be if for some reason a phase 1 is not being done--such as when a phase 1 is more than six months but less than 12 months, or a transaction screen. In such case, I would still want to have EP on if there was a REC to the site.
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Larry, as you know being a prominent member of the VI Task Group, a separate E 2600 VEC analysis only takes place if the VEC analysis is NOT being performed in conjunction with a Phase I. If a Phase I is being performed, the Tier 1 screening methodology in E 2600-10 provides an industry-consensus methodology for the EP to evaluate vapor migration within the context of the Phase I. Since you usually "require VI to be included in a Phase I," I would be interested in the methodology used by your EPs to accomplish this, particularly if it is not the Tier 1 screening methodology in E 2600-10. Attorneys have told me time and time again, they prefer that their EPs use the E 2600-10 screening methodology as a starting point and then add their professional judgment. This represents the least liability for an EP in their view. This is important because as you know, E 1527-05 needs sufficient documentation to be able to be "reconstructed by a third party." Relying on the methodology in E 2600-10 facilitates this documentation. Would you not agree?
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I always require EPs to consider all pathways (including vapor) during phase 1. If a site is flagged because a former on-site use or current/former use at a property within the E1527 database search was involved with COCs, I would ask the EP if further investigation is required because of potential VI.
I expect this conclusion to be based on the totality of circumstances including proximity, geology, conduits, publicly available records, etc. While the EP can use the E2600 tier 1 screening process to advise me if they think vapors may have reached the target property, the EP must use site-specific information and not simply rely on the default search radius. In some cases, an adjacent site might be beyond the E2600 screening distance but there may be specific factors that suggest it could still pose a risk to the subject property. I also rely state VI program protocols.
I dont tend to get mired down with VEC vs REC distinctions. If there is a potential that molecules of a release have reached the property, I consider that a REC that requires further investigation. I dont get much comfort if an EP tells me the vapors likely have fallen ten feet short of the property line because the source is 110 feet away. The primary concern I have encountered and that has been at the center of most VI lawsuits is bodily injury and property damage claims. In most cases, I will want to have some sampling done to verify there are no impacts near the structure though in some cases where is sufficient off-site data, we might use modeling or where permitted by a state or an insurance policy to address the toxic tort claims depending on the risk tolerance of the client.
If we determine that there is a potential for vapors to be migrating onto the property or based on a particular client risk threshold, then the next step would be to determine if the vapors have reached the structures on the target property. At this point, I will turn to my short list of qualified vendors that I call on if we need to proceed to further sampling or mitigation. If the further investigation suggests the pathway if completed, we can then proceed to either risk assessment or mitigation depending on the client risk toleranceonI
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I am sure you are aware that the search radius defining the area of concern was established by experts after significant research on dry cleaner plumes (from trust fund data), petroleum contamination plumes (from almsot 1,000 plumes across the country), chlorinated solvent plumes, volatile organic contaminant plumes, and vapor intrusion sites. The area of concern was based upon 90th percentile plume lengths and knowledge on the distance volatile vapors might migrate in a relatively permeable vadose zone following a path of least resistance. With respect to nearby sites, Tier 1 screening focuses on how far a known or suspect contaminated property with volatiles is from the target property. It is not common in Phase Is to have detailed information on the contaminated plume associated with a nearby contaminated property. As such, using the distances in E 2600-10 screening is not unreasonable. If plume data is available, then it is reasonable for EPs to use the "critical distance" numbers specified in Tier 2 screening. If a client wants confirmation, then it makes sense to do soil gas sampling (as identified in Tier 2 screening), You have indicated that "if there is a potential that molecules of a release have reached the property," you view that as a REC requiring further investigation. This conservative position clearly reflects your concern about potential litigation. Moreover, it is similar to HUD's position with respect to VECs always being RECs, but remember that HUD is dealing with multifamily residential housing where many of the VI class action lawsuits exist. Such a conservative position may be viewed by some as unreasonable for office, retail, and industrial properties involved in commercial real estate transactions.
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Im sure that property owners find E2600 useful to screen out their properties from potential VI concerns but my experience is that it is not particularly suitable for lenders in this current lending environment. It is true that the critical distances were developed a few years ago by a group of experts but the vapor intrusion pathway is incredibly complex-far more so than we even thought a few years ago. We are only now learning how variable VI can be at a single site much less predict its behavior over a distance of hundreds of feet .I have personally encountered petroleum plumes far longer than the 100 foot distance as well as chlorinated plumes over a half-mile long. Sites that we expected to be "hot" turned out to have no VI while others thought to be acceptable turned out to need mitigation.
Because of the unique opportunity I have had working on thousands of securitized loans over the past decade, I have extensive experience evaluating sites with potential or actual vapor intrusion. Indeed, I probably have more experience with this issue than many consulting firms.
The approach I have discussed has been informed by that experience and designed for lenders with certain risk thresholds and reputational risk concerns. It is admittedly not for every client but it provides far more certainty for clients at a fairly reasonable cost.
The plaintiff's bar has discovered vapor intrusion. In many cases, vapor intrusion is the only pathway in these lawsuits. Most of the common law and RCRA actions involving vapor intrusion involve migration of vapors onto residential property from commercial or industrial properties. Often times, the phase 1 performed at a retail or office building that is the source of solvent contamination has discounted or underestimated the potential off-site migration risk. Frequently, consultants discount this potential because the groundwater is not being used or a site is lowly ranked in a state dry cleaner program without realizing that the ranking only factors impacts to drinking water and not potential VI.
Given the uncertainty and the risk thresholds of lenders today, I have found it is far better to generate objective data than rely on assumptions that are likely to be misused or misunderstood by the vast number of consultants doing work for the many phase 1 mills.
The\\\
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Larry, if Tier 1 screening in E 2600-10 is useful to prospective purchasers as you suggest, it clearly will be useful for lenders since they will essentially be partners with prospective purchasers. Moreover, since they are a key stakeholder in due diligence for commercial real estate transactions, I am sure you will agree that they would want to know if a property represents a potential vapor intrusion problem. This clearly is the reason why HUD and Federal Housing Financing Agencies, for example, require Tier 1 VEC screeining using E 2600-10 methodology in Phase Is performed by their EPs. It is also the reason why more and more banks are making sure that Phase Is consider vapor migration on the target property. I believe that you will be hearing more from lenders on this topic at the EBA meeting in Fort Meyers next month.
The second issue you raise relates to uncertainty in the "vapor intrusion assessment" process. The source of this uncertainty is for the most part related to the difficulty in being able to predict with any degree of certainty indoor air contaminant concentrations from sub-slab contaminant concentrations measured by soil gas sampling. Personally, I believe the real problem here is being unable to isolate confounding factors in the indoor air quality measurements. Lack of understanding of air movement in buildings also contributes to confusion in analyzing results. For example, some consultants do not realize that indoor air can actually "contaminate" sub-slab soil gas, particularly when the building is operating under positive pressure as it often is. Movement from sub-slab to indoor air is NOT a one way street, but rather a two way street depending upon the building pressurization cycle.
Finally, it is important to understand that "vapor intrusion assessment" is really a three step process: (1) Can the vapors encroach upon the target property? (This is where E 2600-10 comes in to play); if so, (2) Can the vapors reach a structure on the target property and migrate inside? (This is where federal and state guidance comes into play); and if so, (3) Can vapors migrating into the structure from the sub-surface cause a health problem to human receptors inside the structure? (federal and state guidance also comes into play here). E 2600-10 is focused on vapors migrating onto the target property. Federal and state guidance is focused on vapors migrating into structures on the target property. These are two very distinct assessments. When discussing issues, it is essential that reference be made to the specific step in the vapor intrusion assessment process that is being impacted.
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View from one consultant is this: the vapor-intrusion evaluation I use in doing a Phase I where the client is not paying for a VES (using Standard 2600-10) will be more conservative than the 2600-10 standard calls for. Basically I will use 2600-10 to "eliminate" (actually, to render as non-REC) possible concerns that I would otherwise flag in a Phase I.
I agree with Larry: for commercial-property-transaction Phase I ESAs, the VI pathway is the one most likely to lead to concerns. Very seldom does contaminated groundwater really pose a problem in an urban setting if the contamination is not from volatile chemicals. (That doesn't mean the contaminated GW is not a REC, of course.)
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The reason the legal sub-committee was unable to reach consensus on then proposed change from vapor intrusion to vapor encroachment was because the encroachment finding is really of little value to potentially impacted property owners. The principal liability associated with vapor intrusion is personal injury or property damage claims as opposed to cleanup costs since the owners of properties impacted by off-site releases of COC usually are not liable for remediating such releases.
A VEC does not tell a property owner if it faces potential toxic tort claims since it is essentially only a statement that vapors may have reached the property line. What is valuable for the property owner is to know if the occupants of its property are being exposed. The E2600-10 approach sets up an awkward two-step dance. The old approach of E2600-08 where properties were presumptively screened in unless there were specific facts to overcome the presumption was a more conservative approach that led to the generation of objective data (sampling at the target property to determine exposures).
Many on the legal subcommittee continue to the revisions to E2600 eviscerated its usefulness. It is viewed by many as a tool to be used to commodize the VI process and that can be used by property owners to avoid further VI investigation. It would also appear to be counter to the approach used in California where the screening levels are deliberately set very low so that the risk is assessed. More sites are investigated under the California approach but this lead to more informed judgments.
As I have said, E2600-10 is fine for some clients depending on their greater risk tolerances but it is not a suitable tool for clients with low risk thresholds. And I have a number of case studies from this year alone where had we used the current version of E2600, we would not have discovered actual exposures to occupants from off-site sources. I suspect as we learn more about vapor intrusion, less lenders will be satisfied with using presumptive critical distances but instead go right to sampling like they do with radon gas, LBP, ACM and LIW. There is no substitute for objective data especially when it can be obtained relatively inexpensively.
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(1) The legal subcommittee did reach consensus (per the balloting process) and it was that consideration of vapor migration (encroachment onto a target property) must be considered in an E 1527-05 Phase I REC determination, analogous to groundwater migration.
(2) E 2600-10 has in its title: "vapor encroachment screening on property involved in real estate transactions." There can be no argument that it makes sense for a prospective property owner in conducting due diligence on a property to evaluate the likelihood of vapors to encroach upon the property. If a VEC does not exist, there is little need to be concerned about vapor intrusion problems. If a VEC does exist, then it may be appropriate to investigate further (or even possibly terminate the deal). If a prospective purchaser really wants the property but is concerned about toxic tort claims, then clearly further investigation is in order. Or it may make more sense to just go to pre-emptive mitigation and eliminate the concern.
(3) It is correct that the owner of a property is not liable for cleaning up a nearby VOC-contaminated source impacting his or her property. However, what you can not forget is the fact that there still is an impact on the property and potential costs. For example, suppose the owner of the contaminated site next to the target property (e.g., a former dry cleaner) is no longer around or can't be found? Do you wait for the state to clean it up (which can take years, if ever) and in the meantime, all your tenants leave because they do not want to be exposed to "toxic vapors" and you are unable to attract new tenants because of the stigma on your property? By the way, your tenants may decide to sue you, and even if you are not responsible, you will still have defense costs. And I can go on and on. It should be obvious that getting entangled in a vapor intrusion problem can be costly even if it comes from an off-site source.
(3) There is no one on the legal subcommittee, except for you, as far as I am aware that believes E 2600-10 is "a tool to be used to commodicize the VI process." In fact, this is the first time I have even heard this! E 2600-10 is a technically supportable and conservative methodology that an EP doing a Phase I can use to evaluate vapor migration. An EP does not have to use it if they have an alternative methodology. But the fact is, the legal committee made us all very aware that vapor migration has to be considered in an E 1527-05 Phase I.
(4) In California and other states with risk screening levels, the distances where an assessment must be conducted are related to the distance from the contaminated source (groundwater or soil) to the structure. The distance ("critical distance") in E 2600-10 is from the contaminated source to the property boundary. If E 2600-10 identifies a VEC, then the state risk screening levels would be used IF the nearest potentially impacted structure is within the distance identified in the state VI guidance document. For example, in the VI guidance of many states the assessment process is only initiated if the distance from the contaminated source to the nearest structure is within 100 feet. If it is, the first thing typically required is comparison with the risk screening level appropriate for the contaminated media. If below this level, VI is not a concern (and the VEC would certainly not be a REC under the de minimis provision). If above this level, then the VI investigation must continue. However, a prospective purchaser has many alternatives besides doing further investigation, e.g., for example, he or she can require pre-emptive mitigation to be installed. If rather than a prospective purchaser, you are already the owner of the property (as I believe you are considering in your comment), then the owner of the property has no choice but to do further investigation as he or she can not simply walk away from the deal.
(5) E 2600-10 and the numbers used for screening are very conservative (the opposite of what you imply in your last paragraph). For example, they are based on 90% plume lengths (not average plume lengths). Vapor migration is assumed in vadose zones with relatively permeable soil characteristics. Paths of least resistance for vapor migration are assumed to be directly at the target property.
(6) Finally, if you really believe the distances in E 2600-10 are "not suitable for clients with low risk thresholds," what distances would you advise your EPs to use? I have spoken with hundreds of EPs about the search distances in E 2600-10 and if anything, they believe they are too conservative. To go beyond these distances would clearly involve considerably more work and investigation by the Phase I EP, most of which would be a waste of time. If your clients really have a very low risk threshold, I would suggest that it would be more cost effective to simply do some soil gas sampling on the target property. Remember, E 1527-05 is not an "exhaustive investigation" nor does it "eliminate uncertainty." What it tries to do is balance cost with the value of the information derived. It is really risk management. If you want to eliminate risk, then spend a lot more money investigating the site or buy insurance. By the way, I'll bet you know Superfund site plumes longer than a mile (the search radius in E 1527-05)!
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The legal subcommittee was in fact unable to reach consensus. A handful of lawyers who fought for the change later adopted in E2600-10 continued to push the issue because of concerns about AAI and CERCLA defense implications. The changes were negotiated without input from the legal subcommittee but just those few vocal opponetns of the E2600-08 standard. When the draft work product of those "secret" negotiations was released, most of the those on the legal subcommittee threw up their hands in frustration. Since it was obvious the direction the standard was going and that the train was not going to be derailed, they decided they had expended too much time on this effort and agreed en masse to not cast a ballot. As the chief headcounter, I can state unequivocally that the current standard did not reflect the views of a majority on the legal subcomittee.
I continue to believe that VEC determination is essentially meaningless because it doesnt indicate if there are potential exposures (which is the reason vapor intrusion has become a concern) and may give property owners false sense of security while exposures are continuing. Many of the lawsuits we have seen the past two years involve situations that would have been screened out using E2600-10.
The distances are way too short-especially petroleum. There may be lots of studies funded by the petroleum industry that have been used to support the short distance adopted by E2600 but the idea that a gas station will not likely pose a VI risk beyond the length of home plate to first base is premised on a bunch of assumptions that rarely exist in urban areas. Indeed, we are now learning how the ethanol in blended fuels consumes oxygen as it degrades to methane, thereby retarding the degradation of benzene.
I continue to believe that the changes made to E2600 have rendered the standard essentially worthless to my clients and I do not recommend its use by my clients. I dont see any reason why to use E2600-10 instead of incorporating the vapor pathway in the E1527 process. If a site within the E1527 search radius is flagged as having used COCs currently or in the past, then do a soil gas sample at the target property.
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Larry, you and I will just have to agree to disagree on the views of the legal subcommittee. However, there can be no argument on the outcome of the ballot. There were no negatives, including none from lawyers on your legal subcommittee. If any of them disagreed, they had ample opportunity to vote negative on the ballot.
We will also have to agree to disagree on the value of doing VEC screening. The technical experts on our Task Group believe the VEC screening in E 2600-10 is more than adequate to evaluate vapor migration that may encroach upon a target property. If it does not encroach upon a target property, the likelihood of there being a vapor intrusion problem is nil. If you are aware of specific lawsuits involving contaminated sites that would have been screened out as contributing to a VEC on a target property using E 2600-10 criteria, I would be interested in knowing the specifics, i.e., where the contaminated property was in relation to the target property boundary or where the edge of the contaminated plume was relative to the target property boundary. To my knowledge, no lawsuits exist where E 2600-10 screening would not have worked. Moreover, most involve contamination that is actually on or has reached the target property (which of course would be a VEC under E 2600-10).
You state that you require your EPs to use the E 1527-05 search radii to flag contaminated sites with volatiles used in the past or currently, and if any are within the E 1527-05 search radii, you require soil gas sampling on the target property. You have every right to do this, but I can't see how you do not view this as ultra-conservative. Your consultants must love you as they clearly are doing a heck of a lot of soil gas sampling! In my opinion, if consultants follow this approach on all commercial real estate transactions where Phase Is are done, the commercial real estate industry would be up in arms and these consultants would quickly be out of the Phase I business. One other point I might make is that you are putting heavy reliance on soil gas sampling, which in and of itself has considerable variability. Following your logic and low risk threshold, then, you would likely require a sizeable soil gas sampling investigation, including perhaps even sub-slab sampling. Then again, since soil gas sampling levels as a predictor of indoor air quality levels is tenuous at best, why not go directly to indoor air sampling, and since indoor air sampling has considerable variability as well (time and spatial dependent), I am sure you would want a fairly extensive indoor air investigation! You have to agree that the vast majority of prospective purchasers (other than perhaps your clients) would have a very difficult time accepting this approach if recommended by consultants. I do not mean to go overboard, Larry, but the point I want to make is that the methodology in E 2600-10 is already conservative and if used properly is an excellent methodology (and risk management tool) for screening in commercial real estate transactions.
I think we have discussed the subject ad nauseum. How about we listen to what others think?
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I would like to know how Larry expects consultants to deal with buildings in dense urban environments with high concentrations of contaminated sites. Given in Manhattan we can assuredly expect multiple listings within a 1/8 mile radius and 50 or more within a 1/4 mile radius, coupled with a complex web of utilities providing untold preferential pathways, a VEC could virtually never be ruled out.
So are we going to be sampling indoor air/ soil vapor in every office building in every major city in the next few years? Or will we be recommending subslab depressurization as a routine O&M solution?
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Urban vapor intrusion is particularly problematic and EPA is considering a special initiative for this situation. The VI pathway is incredibly complex and there are just too many variables and possible preferential pathways to "guess away" sites. I have seen sites that one would not have expected to be "hot" and others that were unexpectedly cold.
The only way to know for sure and to eliminate the many "rogue" plumes that exist in our dense urban areas is to do some sampling...it really isnt that expensive or time-consuming and it provides certainty that an educated guess can never provide.
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In an urban setting such as you describe, subslab depressurization is a cheap and reliable solution to the VI problem. So I would probably recommend that an owner implement this solution when buying a property where potential VI issues exist. It's probably less expensive in many cases to implement this presumptive remedy that it is to collect samples in attempting to show the problem doesn't exist.
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Might be time to buy stock in PVC manufacturers. I think we will see many subslab systems installed in the next few years. As Larry notes, vapor migration is tricky to predict and even in less densely developed areas there still are plenty of utility lines to act as a prefered pathway.
Larry, do you reccomend subslab vapor sampling or indoor air?
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