Vapor Intrusion Update: Separating the Environmental exposure from Indoor Air Quality Issues Guidance

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1 Vapor Intrusion Update: Separating the Environmental exposure from Indoor Air Quality Issues Guidance Will Elcoate Alpha Analytical December 5 th. 2014

2 1 Vapor Intrusion is the migration of volatile chemicals from the subsurface into overlying or adjacent buildings.

3 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

4 Vapor Intrusion Guidance VI Pathway Investigative Strategy Stage 1: VI Receptor Evaluation Assess potential for VI Identify receptors Triggers Conceptual Site Model Multiple Lines of Evidence 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 Decision Point 3

5 Assessment Phase 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

6 Multiple Lines of Evidence 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 5

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

8 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

9 NJDEP SRP Program 8

10 NJDEP Vapor Intrusion Screening Levels 9

11 VI Screening/risk levels Verses OSHA Compound EPA Indoor Air VISL EPA Non- Cancer NJDEP Residential NJDEP nonresidential CA DTSC EPA Short term OSHA PEL ug/m3 ug/m3 ug/m3 ug/m3 ug/m3 ug/m3 ug/m3 Benzene NA Ethyl benzene Postponed NA Methylene Chloride NA tetrachloroethene (PCE) NA trichloroethene (TCE) EPA Region 3 Generic risk Tables

12 OSHA Applicability 2 buildings on same site VISL Applicable Office PCE μg/m 3 OSHA Applicable Warehouse (uses PCE) PCE 7,500 μg/m 3 Office Occupants not covered by OSHA VISLs are applicable 47 ug/m3 IA PCE > RAL PCE 25,000 μg/m 3 Warehouse PCE utilized in building OSHA PELs are applicable 680,000 ug/m3 Adapted from a Slide: J Boyer NJDEP 11

13 ITRC PVI Work group 12

14 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

15 Example of Biologically Active Vadose Zone Figure 6 Typical vertical concentration profile in the unsaturated zone for PHCs, O2, CO2. (modified from Roggemans et al, 2001). 14

16 Inclusion Zone Initial determination: Source strength and separation distance between contamination and receptors 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 ITRC 15

17 Air Phase Analytical Methods 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 20

18 Indoor Air Sampling AMBIENT AIR UPSTAIRS DOWNSTAIRS ATTACHED GARAGE BASEMENT INDOOR AIR AMBIENT AIR Foundation Crack SUBSLAB AIR CRAWLSPACE / BASEMENT AIR Courtesy of Thomas McHugh GSI Environmental Inc. Battelle Bioremediation Symposium 2011 Reno, Nevada

19 Some sampling considerations 18

20 Pre-Planning Indoor Air Sampling Challenge of indoor Air Sampling: Identify building use and operation parameters Identify & remove Indoor air VOC sources

21 Background Volatile Compounds Tobacco Smoking Stored solvents Attached garage Dry cleaning Scented candles Christmas tree ornaments Remodeling materials Cleaning with bleach 20

22 Background Volatile Compounds EPA 2002 ug/m

23 Background Volatile Compounds Median concentration

24 Background Volatile Compounds

25 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 24

26 Questions Contact: Will Elcoate National Air Product Manager Tel: