Taryn McKnight – Client Relations Manager Vapor Intrusion: Improving Data Quality Using Today’s Guidance and Best Practices Taryn McKnight – Client Relations Manager

Volatile chemicals from the subsurface intrude into overlying buildings. http://www.epa.gov/oswer/vaporintrusion/

Vapor Intrusion Timeline EPA Adds Subsurface Intrusion to the Superfund Hazard Ranking System 2016 EPA OSWER finalizes Vapor Intrusion Guidance 2015 EPA OUST and ITRC work to publish Petroleum Vapor Intrusion Guidance 2014 OSWER works to finalize 2002 Draft Vapor Intrusion Guidance 2013 ASTM D7663-11 Standard Practice Active Soil Gas 2011 ASTM E2600-10 Standard Guide Vapor Encroachment 2010 ITRC Publishes Vapor Intrusion Guidance 2007 NY Re-opens 1400 NFR Sites 2006 OSWER replaces RCRA 2002 Redfield Rifle/CDOT 1998 J&E model 1991 1990 1995 2000 2005 2008 2012 2014 2015 2016 2001 - 2008 Many States Publish VI Guidance 2008 EPA Publishes Attenuation Factor Database 1995 - 2000 States begin addressing Vapor Intrusion: MA, CT, CA 2010 - 2014 Many organizations are hard at work, updating and finalizing guidance and standards 2015 Final Guidance is published 2016 Addition of VI to HRS and current debate over short term TCE risk Modified from: M. Traister, O’Brien & Gere

Final VI Guidance FINALLY! http://www.epa.gov/oswer/vaporintrusion/

Note important updates to Indoor Air Testing Page 15, Table 1-2 Note important updates to Indoor Air Testing http://www.epa.gov/oswer/vaporintrusion/

Key Recommendation Highlights Limit analyses to chemicals of concern Section 6.4 Assess the VI pathway using multiple lines of evidence Sections 6.3, 7.1 & 7.2 Generally support the decision to collect indoor air data Document objectives and methods in a VI workplan Consider collecting multiple rounds of indoor air samples Section 6.3.4 & 6.4.1 Section 7.4 Section 6.2

Conceptual Site Model (CSM) & Data Quality Objectives (DQOs) Considerations: Site conditions & historical data Compounds of concern & anticipated concentrations Screening levels Sampling protocols Involve the lab early on “A CSM integrates all lines of site-specific evidence into a three dimensional conceptualization of site conditions…” Section 2.0 Section 2.0 The CSM will help guide the DQOs CONFIDENTIAL-For distribution by TestAmerica only

Sources of Variability http://www.itrcweb.org/gd_VI.asp Potential Sources of Variability in Measured Data Barometric pressure Surface cover Preferential pathways Soil moisture & permeability Building depressurization Seasonal effects: Advection Biodegradation Background air ITRC 2007

Vapor Intrusion: Impacts to Data Stack Effect Barometric Pressure Changes Wind Effect Vapor Transport: Concentration Pressure & Temperature gradient Indoor sources: carpet, dry cleaning, air fresheners, glues, paint, solvents, smoke, cleaning supplies, heating oil Other sources: Vapor Intrusion, Ambient Air Intrusion Vapors In/Out Ambient Background Breathing Zone HVAC Lithology Preferential Pathways Vapors in Soil moisture content Vapors out Water Table Vadose Zone Contaminated Groundwater CONFIDENTIAL-For distribution by TestAmerica only 9

Multiple Lines of Evidence http://www.epa.gov/oswer/vaporintrusion/ CONFIDENTIAL-For distribution by TestAmerica only

“A potential shortcoming of indoor air is background” Indoor Air Sampling Pros Actual concentration, no modeling, no attenuation Relatively quick, no drilling Less spatial variability than subsurface Cons Working with the “Homeowner” Access agreements, factsheets, meetings Requires removal of interior or lifestyle sources Contribution from unknown indoor sources Per EPA: Collect indoor samples and compare with controls: sub slab, ambient, lines of sight evidence Section 6.4.1 “A potential shortcoming of indoor air is background” CONFIDENTIAL-For distribution by TestAmerica only

“A potential shortcoming of indoor air is background” Indoor Air: Active or Passive Active Sampling Considerations CoCs Screening Levels Litigious site? Passive Sampling Considerations Desire for long term monitoring Environmental conditions Target analyte list and RLs Per EPA - Collect indoor samples and compare with controls: Sub slab, ambient, lines of sight and building evidence Passive samplers “their use may grow…” Section 6.4.1 “A potential shortcoming of indoor air is background” CONFIDENTIAL-For distribution by TestAmerica only

Background Contamination Common Household Contaminants Acetone Formaldehyde Benzene n-Heptane Bromomethane n- Hexane 2-Butanone (MEK) Methylene chloride Chlorobenzene Methyl isobutyl ketone Chloroethane Methyl tert butyl ether Chloroform Styrene Cyclohexane 1,1,2,2-Tetrachloroethane 1,4-Dichlorobenzene Tetrachloroethene (PCE) Dichlorodifluoromethane Toluene 1,1-Dichloroethane 1,1,1-Trichloroethane 1,3-Dichloropropene Trichloroethene (TCE) Ethylbenzene Xylenes, total Source: NJDEP Consumer Activities Household Products Building Materials Outdoor Air Section 6.3.5 Identify & Evaluate Contributions from Indoor & Ambient Sources http://www.state.nj.us/dep/srp/guidance/vaporintrusion/ CONFIDENTIAL-For distribution by TestAmerica only 13

Sub Slab Sampling Pros Can resolve indoor sources Can assess if the VI pathway is complete Can be used to assess the potential for VI risk Cons Method is intrusive Requires access agreements Substantial spatial variability under the slab Per EPA: Collect multiple samples to address spatial variability and multiple rounds to address temporal variability Section 6.4.3 “There may be substantial spatial variability in sub-slab soil gas” CONFIDENTIAL-For distribution by TestAmerica only

Soil Gas Sampling Pros Provides an estimate of vapor concentrations Can be performed without entering the structure Cons Significant spatial variability May not be representative of vapor concentrations under buildings Per EPA: “Several rounds of sampling are generally recommended, particularly…” Section 6.4.4 “individual exterior soil gas samples cannot generally be expected to accurately estimate sub-slab or indoor air concentrations” Modified from: Rick Ehrhart, RCRA Corrective Action, EPA Region 6 CONFIDENTIAL-For distribution by TestAmerica only

Soil Gas/Sub Slab Sampling Guidance http://www.dtsc.ca.gov/SiteCleanup/upload/VI_ActiveSoilGasAdvisory_FINAL_043012.pdf https://www.health.ny.gov/environmental/investigations/soil_gas/svi_guidance/docs/svi_main.pdf CONFIDENTIAL-For distribution by TestAmerica only 16

Soil Gas Sampling Protocols Purge tubing Using a syringe, bag or canister Flow rate for purging/collecting <200mls/min Using a flow controller Apply a tracer gas (e.g. helium, Freon or IPA) Measure for biodegradation at petroleum sites Test for CH4, O2 and CO2 Using a shroud, a field detector and a tracer gas CONFIDENTIAL-For distribution by TestAmerica only

Leak Check Considerations Liquid (qualitative) or Vapor (quantitative) Shroud Field or Laboratory analysis Reporting limit requirements Estimated values exceed the calibration range Section 6.4.4 “a reliable seal of the annulus between the probe and the probe housing and leak testing for the seal are generally recommended” https://www.health.ny.gov/environmental/investigations/soil_gas/

Real World Shrouds http://www.deq.mt.gov/statesuperfund/viguide.mcpx/Appendix_E_SubslabSoilGasSamplingPictureGuidance.pdf https://www.nj.gov/dep/srp/guidance/vaporintrusion/vig_main.pdf

Shut-in Leak Test Remove brass plug Loosen FC fitting Attached FC to Can Finger tighten ¼ turn with wrench Attach brass plug to FC Tighten with wrench Open and close valve Observe gauge reading http://www.epa.ohio.gov/portals/30/rules/vapor%20intrusion%20to%20indoor%20air.pdf

“T-fitting” or “Co-locator” Field Quality Control Samples Field Duplicates Requires the use of a “T-fitting” or “Co-locator”

Media Certification and Management Segregated for cleaning Low level (ambient & indoor) Source level (soil gas) Cleaning Evacuated, heated, flushed Certification Batch or individual Overnight leak check test

Gauges, Impact to Data? Field Sampling Media Initial Vacuum – sufficient vacuum Range will be 25-30”Hg Final Vacuum – sufficient sample Range should generally be 10-0”Hg CONFIDENTIAL-For distribution by TestAmerica only

Shipping, Preservation and Holding Times Section 6.4.1 “Fourteen days is the most commonly cited hold time for air samples in canisters” Canisters No preservation required Can be shipped by air with few caveats Hold time specified in TO-15 is 30 days

EPA Indoor Air Screening Levels http://www.epa.gov/reg3hwmd/risk/human/rb-concentration_table/Generic_Tables/docs/resair_sl_table_01run_November2014.pdf CONFIDENTIAL-For distribution by TestAmerica only

Target Analyte Lists - Volatile? The primary focus of Vapor Intrusion = Volatiles Not everyone agrees what constitutes a VOC SVOCs Metals Pesticides/PCBs Require sorbent/filter methods TO-13A, TO-10A, 6010

U.S. EPA VISL Calculator From the new guidance: 6.5.2 EPA developed VISLs for human health protection that are generally recommended, medium-specific, risk-based screening-level concentrations… These VISLs calculated are based on: • Current toxicity values (OSWER’s EPA 2003). • Physical-chemical parameters for vapor-forming chemicals • EPA-recommended approaches for HHRA (EPA 2009c, 2014a)

Screening Levels – What Questions to Ask State or Federal? Soil gas or Indoor air? Residential/Commercial attenuation factor? Units? Target analyte list? EPA RSLs or State Limits Do limits exist for your matrix If not, how will you calculate for them? Be careful of units! Will you limit the list and does it include non-volatiles?

Commonly Requested Methods VOCs: TO-15, TO-17 Hydrocarbons: TO-15, TO-3 Fixed Gases: ASTM D-1946 SVOCs: TO-13A Diesel Range: TO-17 Carbon Range Speciation: MA APH

EPA Method TO-15 FAQs: EPA Method TO-15 was written for the determination of VOCs in ambient air collected in specially-prepared canisters and analyzed by GC/MS at concentrations above 0.5 ppbv. Method TO-15 is appropriately applied to only a subset of the 97 Title III VOCs, therefore a standard TO-15 list was not established. CONFIDENTIAL-For distribution by TestAmerica only

SIM vs. Full Scan “SIM” Selected Ion Monitoring – the process by which the instrument method is limited to detecting selected ions Full Scan Spectra SIM Spectra

Summary Do not take samples unless you have some idea of what the data is going to tell you - Conceptual Site Model Define your data quality objectives up front, this will determine the appropriate containers, collection procedures and analyses Teamwork with your laboratory up front will ensure less questions when you receive the data Data quality is a function of the whole process: the project set up, the field sampling protocols, and the analytical protocols

Taryn McKnight taryn.mcknight@testamericainc.com Questions? Taryn McKnight taryn.mcknight@testamericainc.com