What the difference is, and why lawyers, bankers, regulators, and the regulated community should care

Steve CriderMay 7, 2014

Vapor Encroachment Screening (VES) and Vapor Intrusion (VI) Assessment

News articles

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

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)

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

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

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

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)

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

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

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

ASTM E2600-10: additional terminology

• Vapor encroachment condition (VEC)

• Area of concern (AOC)

• Critical distance

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

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

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

ASTM E2600-10: methodology

• Getting down to business

ASTM E2600-10: Tier 1 initial screening for VECs

• Designed as screening step to supplement Phase 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

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

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

− 30 ft. for dissolved petroleum hydrocarbon sources

• Cross-gradient− 100 ft. for COC sources/petroleum hydrocarbon LNAPL sources +

plume-width consideration

− 30 ft. for dissolved petroleum hydrocarbon sources + plume-width consideration

ASTM E2600-10: net reduction in AOC for Tier 1 screening of known or suspected petroleum sources

Source location E2600-10 E2600-10 w/ Buonicore methodology*

Upgradient 528 ft. 528 ft.

Downgradient 528 ft. 100 ft. (LNAPL)30 ft. (dissolved)

Cross-gradient 528 ft. 165 ft. (LNAPL)95 ft. (dissolved)

* Buonicore, A.J., Screening for Potential Vapor Intrusion Problems, Paper #129, Proc. AWMA 102nd Annual Conference , Detroit, MI, June 16–19, 2009, and Buonicore, A.J., Methodology for Identifying the Area of Concern Around a Property Potentially Impacted by Vapor Mitigation from Nearby Contaminated Sources, Paper No. 2011-A-301, Proceedings, AWMA 104th Annual Meeting in Orlando, FL, June 20–24, 2011

ASTM E2600-10: net reduction in AOC for Tier 1 screening of known or suspected COC sources

Source location E2600-10 E2600-10 w/ Buonicore methodology*

Upgradient 1,760 ft. 1,760 ft.

Downgradient 1,760 ft. 100 ft.

Cross-gradient 1,760 ft. 365 ft.

* Buonicore, A.J., Screening for Potential Vapor Intrusion Problems, Paper #129, Proc. AWMA 102nd Annual Conference , Detroit, MI, June 16–19, 2009, and Buonicore, A.J., Methodology for Identifying the Area of Concern Around a Property Potentially Impacted by Vapor Mitigation from Nearby Contaminated Sources, Paper No. 2011-A-301, Proceedings, AWMA 104th Annual Meeting in Orlando, FL, June 20–24, 2011.

EDR VEC app

EDR VEC app (cont.)

EDR VEC app (cont.)

ASTM E2600-10: EP judgment

• 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

ASTM E2600-10: Tier 1 conclusions

1. A VEC exists (physical evidence)

2. A VEC likely exists (within close proximity, e.g., two properties?)

3. A VEC cannot be ruled out (further away, beyond two properties?)

4. VEC can be ruled out because it does not or is not likely to exist (you are done!!)

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

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

ASTM E2600-10: Tier 2 more refined screening

Critical Distance100 ft for NAPL COCs30 ft for Dissolved Petro

Critical Distance• TP Property Boundary• Existing or proposed building• Vapor Conduits

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

ASTM E2600-10: Tier 2 conclusions

1. VEC exists (physical evidence)

2. VEC likely exists (within close proximity, e.g., two properties?)

3. VEC cannot be ruled out (further away, beyond two properties?)

4. VEC can be ruled out because it does not or is not likely to exist (you are done!!)

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

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

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…

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

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

Final thoughts

• Not required for ASTM E 1527-13, but a useful guide!