Vapor Intrusion Update: Separating the

Environmental exposure from Indoor Air

Quality Issues Guidance

Will Elcoate

Alpha Analytical

December 5th. 2014

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Vapor Intrusion is the migration of volatile chemicals from the subsurface

into overlying or adjacent buildings.

www.epa.gov/correctiveaction/eis/vapor.html

EPA updates VI Guidance: 2015?

Draft Final Vapor Intrusion Guidance Documents

• OSWER Final Guidance For Assessing And Mitigating The Vapor

Intrusion Pathway From Subsurface Sources To Indoor Air —

External Review Draft (PDF) (196 pp, 4.1MB, About PDF)

• Guidance For Addressing Petroleum Vapor Intrusion At Leaking

Underground Storage Tank Sites—External Review Draft.

• Public comment period ended in July 2013

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http://www.epa.gov/oswer/vaporintrusion/

Vapor Intrusion Guidance

VI Pathway Investigative Strategy

Stage 1: VI Receptor Evaluation

• Assess potential for VI

• Identify receptors

• Triggers

Stage 2: VI Investigation

• Develop and implement VI Investigation

• Evaluate data using applicable screening levels

Stage 3: Mitigation

Stage 4: Operations, Maintenance and Monitoring

Stage 5: Termination

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Conceptual

Site Model Multiple

Lines of Evidence

Decision Point

Assessment Phase

http://www.epa.gov/oswer/vaporintrusion/basic.html

Conceptual Site Model

• Potential release sources

• Nature and extent impacts

• Potential migration pathways

• Potential sources of vapor

intrusion

• Concentrations and extent of

VOCs in soil and groundwater

• Potential indoor air receptors

Multiple Lines of Evidence

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Site specific conditions that can make

each site unique, can include:

• Sub- Surface lithology/ stratigraphy

• Building construction and condition

• Presence of preferential pathways

• Sub slab & Soil Gas data

• Groundwater spatial data

• Seasonal & temporal effects

• Indoor Air Data

• Constituent Ratios

• Modeling data ITRC 2007 Vapor Intrusion

Vapor Intrusion Guidance

CT

Draft or Final Guidance, numerical standards or program requires addressing vapor intrusion. No formal guidance.

State VI Guidance

NE States

• NY 2006 Final Guidance

• VT VI Incorporated into Site Cleanup Program April 2012

• NH Guidance July 2011, Update to Screening levels FEB2013

• ME Guidance 2010 Update in the works

• MassDEP VI Interim Final DEC2011: MCP Update 2013

• RI EPA/ITRC - RI Schools Sept 2012

• CT defer to EPA/ITRC. Volatility Guidance 2003

• NJ Update VITG Jan/MAR2013 with new Vapor Intrusion SLs

(VISLs)

EPA Region 3 Generic risk Tables http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/

NJDEP SRP Program

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NJDEP Vapor Intrusion Screening Levels

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VI Screening/risk levels Verses OSHA

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https://www.osha.gov/dsg/annotated-pels/tablez-1.html

Compound

EPA Indoor

Air VISL

EPA Non-

Cancer

NJDEP

Residential

NJDEP non-

residential CA DTSC

EPA

Short

term

OSHA PEL

ug/m3 ug/m3 ug/m3 ug/m3 ug/m3 ug/m3 ug/m3

Benzene 0.36 31 2 2 0.084 NA 32000

Ethyl benzene 1.1 100 2 5 Postponed NA 435000

Methylene Chloride 100 630 96 1200 0.41 NA 87000

tetrachloroethene (PCE) 11 42 9 47 0.47 NA 680000

trichloroethene (TCE) 0.48 11 3 3 1.31 2 540000

EPA Region 3 Generic risk Tables

http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/

http://www.nj.gov/dep/srp/guidance/vaporintrusion/vig_tables.pdf

OSHA Applicability

PCE – 7,500 μg/m3

PCE – 25,000 μg/m3

OSHA Applicable VISL

Applicable

PCE - 450 μg/m3

Office • Occupants not covered

by OSHA

• VISLs are applicable

• 47 ug/m3

IA PCE > RAL

Warehouse

• PCE utilized in building OSHA PELs are applicable

• 680,000 ug/m3

Office Warehouse

(uses PCE)

2 buildings on same site

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Adapted from a Slide: J Boyer NJDEP

ITRC PVI Work group

http://www.itrcweb.org/PetroleumVI-Guidance/ 12

Petroleum Vapor Intrusion

Petroleum hydrocarbons (PHCs) such as gasoline, diesel, and jet fuel

verses

Chlorinated solvents; dry cleaning chemical and the degreasers

Typical petroleum hydrocarbon

transport conceptual scenario

Typical chlorinated solvent transport

conceptual scenario

Example of Biologically Active Vadose Zone

14 Figure 6 Typical vertical concentration profile in the unsaturated

zone for PHCs, O2, CO2. (modified from Roggemans et al, 2001).

Inclusion Zone

• Vapor Intrusion may not be a

concern if free product

(LNAPL) is > 30 feet

• or > 5 feet from dissolved

phase provided there is clean

(Biologically active) soil

between source and receptor

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ITRC

Initial determination:

Source strength and separation distance

between contamination and receptors

Air Methods for Vapor Intrusion EPA TO-15 VOC’s

EPA TO-15 Carbon Ranges & TPH, PIANO

EPA TO-15 TO-15 MassDEP-APH: Air Phase Hydrocarbon Analysis

Full Scan /SIM RL’s

Soil Gas Full Scan SIM

2.0 ppbv 0.2 ppbv 0.02ppbv

Natural Attenuation Parameters

Oxygen Carbon Dioxide & Methane

EPA Method 3C: Method ASTM 1946

Other Potential methods NIOSH 6009 Mercury

TO10A - PCBS TO13Mod – PAH’s

TO17 – VOC’s

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Air Phase Analytical Methods

AMBIENT AIR

UPSTAIRS

BASEMENT

ATTACHED

GARAGE

Foundation Crack

DOWNSTAIRS

AMBIENT AIR

CRAWLSPACE /

BASEMENT AIR

Indoor Air Sampling

INDOOR AIR

SUBSLAB AIR

Courtesy of Thomas McHugh GSI Environmental Inc.

Battelle Bioremediation Symposium 2011 Reno, Nevada

Some sampling considerations

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Challenge of indoor Air Sampling:

• Identify building use and operation parameters

• Identify & remove Indoor air VOC sources

Pre-Planning Indoor Air Sampling

• Tobacco Smoking

• Stored solvents

• Attached garage

• Dry cleaning

• Scented candles

• Christmas tree ornaments

• Remodeling materials

• Cleaning with bleach

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Background Volatile Compounds

Background Volatile Compounds

EPA 2002 ug/M3

400

7000

0.31

7000

2.2

5.2

0.11

0.81

3000

1.6

0.15

0.022

30000

70

200

0.28

35

500

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Median concentration

Background Volatile Compounds

http://householdproducts.nlm.nih.gov/

Background Volatile Compounds

Summary

• Much anticipated EPA VI Guidance may be released in

2015

• ITRC has released its PVI guidance that with the 2007

VI Guidance is becoming the basis for most recently

published/updated guidance

• There will continue to be significant differences in State

Guidance, although the gap is closing.

• Because of the site specific variability; the challenge of

VI is taking representative and relevant samples

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Contact:

Will Elcoate

National Air Product Manager

Tel: 508.330.3753

welcoate@alphalab.com

Questions