Presentation Transcript

1. Vapor Encroachment Screening (VES) and Vapor Intrusion (VI) Assessment What the difference is, and why lawyers, bankers, regulators, and the regulated community should care Steve CriderMay 7, 2014
2. News articles
3. Acronym list AOC: area of concern VES: vapor encroachment screen VEC: vapor encroachment condition VI: vapor intrusion TP: target property COC: chemical of concern LNAPL: light nonaqueous-phase liquids DNAPL: dense nonaqueous-phase liquids EP: environmental professional
4. Vapor encroachment and the vapor intrusion assessment process Are there actual or potential volatile vapors encroaching on the target property (TP)? (addressed by ASTM E 2600-10) If so, can these vapors migrate into structures on the property? (addressed by federal/state VI guidance) If so, can they represent an indoor air-quality problem? (addressed by federal/state VI guidance)
5. Informal survey: consultants and the vapor pathway MDEQ has focused on VI, May 2013 published a guidance document; ASTM updated Phase I ESA standard practice which now specifically mentions vapor, so are we, consultants, doing any better? Not yet BEAs still targeting soil and groundwater Vapor typically an afterthought during due-care planning process, resulting in: Insufficient or no vapor data Presumptive remedies Of the five BEAs on desks of district staff, only one mentions vapor assessment in Phase I ESA
6. Root cause(s)??? Cost and time to conduct soil-gas sampling Soil gas not its own criteria;SVIIC and GVIIC not typically facility status drivers Vapors not thoroughly assessed or considered in Phase I ESA process
7. Using ASTM E2600-10 or an alternative If a company develops its own methodology, it must be well enough documented in the Phase I ESA to allow a third party to reconstruct the analysis Advantages of using Tier 1 in ASTM E2600-10 Methodology standardized through ASTM consensus process Developed by industry VI experts Ability to use (without further documentation) critical distances in E2600-10 Reduced liability
8. ASTM E2600-10: overview NOT A REQUIREMENT FOR ASTM 1527-13 Standard guide not standard practice Focused solely on likelihood of migrating vapors to encroach on TP (creating a vapor encroachment condition, or VEC)
9. ASTM E2600-10: purpose Provide practical guidance and useful process for conducting a vapor encroachment screen (VES) on a property parcel involved in a real estate transaction in the U.S. with respect to chemicals of concern (COCs) that may migrate as vapors onto a property as a result of contaminated soil and groundwater on or near the property
10. ASTM E2600-10: objective Whether or not encroaching vapors result in intrusion requires investigation beyond scope of standard Objective: identify VECs, analogous to identifying Recognized Environmental Conditions in ASTM E1527
11. ASTM E2600-10: summary Two levels of screening for VECs: Tier 1: focuses on known or suspected contaminated sites in AOC as identified in ASTM E1527 investigations (government records investigation, historical research, etc.) Tier 2:focuses on plumes from any contaminated sites in AOC and their proximity (critical distance) to TP, or actual sampling to identify if vapors have encroached on TP
12. ASTM E2600-10: additionalterminology Vapor encroachment condition (VEC) Area of concern (AOC) Critical distance
13. ASTM E2600-10: vapor encroachment condition Actual or likely presence of COC vapors in subsurface of TP, caused by release of vapors from contaminated soil or groundwater on or near TP
14. ASTM E2600-10: area of concern Measured from TP boundary to known or suspected contaminated property 1/3 mile for known or suspected contaminated sites with COCs (volatile or semivolatile hazardous substances) 1/10 mile for known or suspected contaminated sites with petroleum hydrocarbon COCs May be reduced in cross-gradient and side-gradient direction if groundwater flow direction is known
15. ASTM E2600-10: critical distance Defined as distance from nearest edge of contaminated plume to nearest TP boundary Measured linearly in any direction: horizontal, vertical, etc. 100 ft. for COCs 30 ft. for dissolved volatile petroleum hydrocarbons 100 ft. for petroleum LNAPL accumulating above water table What about DNAPL?: treat as COC
16. ASTM E2600-10: methodology Getting down to business
17. ASTM E2600-10: Tier 1 initial screening for VECs Designed as screening step to supplementPhase I ESA;relies on information already collected in investigation Review of governmental and historical records at specific search distances to identify COC-contaminated properties within AOC 1/3 mile for known or suspected contaminated sites with COCs (volatile or semivolatile hazardous substances) 1/10 mile for known or suspected contaminated sites with petroleum hydrocarbon COCs
18. ASTM E2600-10: most prevalent sources of concern Present and former: Gas stations and auto repair sites Scrap-metal sites Manufactured gas plant sites Dry-cleaning sites Industrial sites, particularly those using chlorinated solvents for degreasing and parts cleaning Municipal solid waste landfills and open dumps Hazardous-waste disposal sites
19. ASTM E2600-10: Tier 1 AOC when groundwater flow direction can be estimated Upgradient 1/3 mile for COC sources 1/10 mile for petroleum hydrocarbon sources Downgradient 100 ft. for COC sources/petroleum hydrocarbon LNAPL sources 30ft. for dissolved petroleum hydrocarbon sources Cross-gradient 100 ft. for COC sources/petroleum hydrocarbon LNAPL sources + plume-width consideration 30ft. for dissolved petroleum hydrocarbon sources + plume-width consideration
20. ASTM E2600-10: net reduction in AOC for Tier 1 screening of known or suspected petroleum sources
21. ASTM E2600-10: net reduction in AOC for Tier 1 screening of known or suspected COC sources
22. EDR VEC app
23. EDR VEC app (cont.)
24. EDR VEC app (cont.)
25. ASTM E2600-10: EPjudgment Type of TP Location of contamination source Cleanup status of contaminated site Depth to groundwater Soil characteristics Presence of “vapor conduits” (MDEQ favorite) Presence of hydraulic or physical barriers
26. ASTM E2600-10: Tier 1 conclusions A VEC exists (physical evidence) A VEC likely exists (within close proximity, e.g., two properties?) A VEC cannot be ruled out (further away, beyond two properties?) VEC can be ruled out because it does not or is not likely to exist (you are done!!)
27. ASTM E2600-10: Tier 1 conclusions (cont.) If 1, 2, or 3, determine if VEC is a REC if done in conjunction with Phase I ESA “De minimis” (?) Apply state VI guidance criteria (?) Other (?) If 1, 2, or 3, EP and user decide whether further investigation (such as proceeding to Tier 2 or state program) is warranted
28. ASTM E2600-10: Tier 2 more refined screening Non-invasive If Phase II data on contaminated source exist, proximity of contaminated plume to TP is evaluated Plume test / critical-distance evaluation
29. ASTM E2600-10: Tier 2 more refined screening Critical Distance 100 ft for NAPL COCs 30 ft for Dissolved Petro Critical Distance TP Property Boundary Existing or proposed building Vapor Conduits
30. ASTM E2600-10: Tier 2 invasive Invasive (soil, groundwater or soil gas sampling) If Phase II data on contaminated source does NOT exist, or If preferential pathway exists (natural or constructed), or If VEC is identified in Tier 1 and you want to do confirmatory sampling (follow state program), or If client or lender is more comfortable with sampling (follow state program). Sampling can be done at the TP boundary to identify whether vapors are encroaching on TP Plume test / critical-distance evaluation
31. ASTM E2600-10: Tier 2 conclusions VEC exists (physical evidence) VEC likely exists (within close proximity, e.g., two properties?) VEC cannot be ruled out (further away, beyond two properties?) VEC can be ruled out because it does not or is not likely to exist (you are done!!)
32. ASTM E2600-10: Tier 2 conclusions (cont.) If 1, 2, or 3 then determine if VEC is a REC if done in conjunction with a Phase I ESA “De minimis” (?) Apply state VI guidance criteria (?) Other (?) If 1, 3, or 3, EP and user decide whether further investigation (such as state program) is warranted
33. Why do we care about E2600-10 if it’s not part of a Phase I ESA? ASTM E1527-13 Section 3.2.56 lists term VAPOR—so EP must consider it during Phase I ESA ASTM E2600 and Buonicore method provide hard numbers to rely on for determining REC or no REC Gut feelings are great, but having data to support your position helps lawyers sleep at night
34. Why do I care about E2600-10 if it’s not part of a Phase I ESA? (cont.) Both ASTM E1527-13 and E2600-10 rely on EP’s professional judgment, so ultimately it’s still up to you Using guidance in E2600-10 does not mean you have to write a full report…
35. Scope of work: Tier I Add-on to Phase I ESA Modified questionnaire (see Appendix 3) Report format follows 1527 so you need to add only subsections that discuss vapor in “records review, findings, opinions, and conclusions” section of report
36. Scope of work: Tier 2 Non-intrusive More extensive file review of State/Local records Letter-style report documenting reports reviewed and plume distances measured to nearest TP boundary (the critical-distance assessment) Intrusive sampling Follow state guidelines
37. Final thoughts Not required for ASTM E 1527-13, but a useful guide!