Case Study: Vapor Intrusion in the Fruit Valley Neighborhood, C d tM Cadet Manufacturing f t i g and dS Swan M Manufacturing f t i g Washington State Department of Ecology, Toxics Cleanup Program Craig Rankine, RG, LHG Utility Line: Preferential Pathway

Stack Effects Advective vapor Flow Cracks/Openings

Effects of Atmospheric Pressure (Barometric Pumping)

Vapor Source from Indoor

Oxygen Vapor Migration Wind Effects

Affected Groundwater G ou d ate

Typical Example of Vapor Intrusion Pathway

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Presentation Overview Presentation Overview • Project background • Vapor intrusion (VI) case study • How the VI guidance works in this  H th VI id k i thi investigation • Beyond the VI guidance y g

Regulatory Status g y Two sites:  Cadet Manufacturing   g Swan Manufacturing   Located at and near the Port of  Vancouver, Vancouver USA. Vancouver, Vancouver USA. o Swan ‐ groundwater contamination  investigated in 1997, first agreed order  1998, remedial investigation approved 1998, remedial investigation approved  in 2009 o Cadet ‐ groundwater contamination  investigated in 1998, first agreed order investigated in 1998, first agreed order   2000, remedial investigation approved  in 2010 o Trichloroethylene (TCE) in use between  Trichloroethylene (TCE) in use between the sites from 1956 to 1976 o 9 9 o

Fruit Valley Neighborhood, Vancouver:  Vapor Intrusion Case Study Vapor Intrusion Case Study Fruit Valley  Neighborhood North Fruit Valley

South Fruit Valley

Site History and VI Prelim Assessment y Are VOCs present, toxic and near buildings? • Both Swan and Cadet used Trichloroethylene (TCE)   Both Swan and Cadet used Trichloroethylene (TCE) to vapor degrease/clean metal parts before  painting. • Both sites are close to residential areas. • Early on TCE and other VOCs were found in  groundwater and soil gas beneath residential groundwater and soil gas beneath residential  areas and buildings • Further VI assessment is needed  • Move to next tier: Tier I. 

Tier I Assessment Determine from sampling if VOCs concentrations  are high enough to pose a VI threat? are high enough to pose a VI threat? • Shallow GW contains TCE and PCE above VI  screening levels of 0.42 and 1.0 ug/L ,  respectively • TCE and PCE is found in soil gas (  living space • VOC levels highest of  g houses sampled • Highest VOC  Highest VOC detections in pairs • Same compounds seen  Same compounds seen at high levels

North Fruit Valley

Cadet

Swan

South Fruit Valley

Indoor Air Investigation  • Samples collected  l ll d during 15 separate  events between events between  2002 and 2008 • 702 samples collected  f from 121 homes in the  121 h i th NFVN • 82 samples collected  82 samples collected from 20 homes in the  SFVN • Multi‐media sampling  done

North Fruit Valley

Cadet

Swan

South Fruit Valley

Interim Actions Interim Actions • Source Areas – Excavation & treatment of 13,800 yd f d3 soill – Injection of oxidizing compounds into GW source and  neighborhood plume areas neighborhood plume areas – Source area air sparging /soil vapor extraction – Groundwater pump and treat (2,500 gpm)

• House by House – Seal basements and foundations – early on – Remove products that cause indoor air sources – early  on – Install soil vapor vacuum systems in six homes Install soil vapor vacuum systems in six homes

TCE Isoconcentrations in Shallow Groundwater September 2007

LEGEND

Determining VI Source Determining VI Source • Outdoor air VOCs influence indoor air levels – Expect indoor air VOCs levels to be same as  ambient air levels  – Collect upwind outdoor air samples next to  buildings – Guidance allows subtraction of ambient air level,  what is left is VI or indoor air sourced – VOCs in indoor air not in groundwater, soil gas or  outdoor air, are indoor air sourced

Determining Background Determining Background • Outdoor air influences indoor air levels – Collect upwind outdoor air samples in areas close  to but not in areas of groundwater contamination – Used MTCAStat to calculate background air levels  – Subtract background level, what is left is VI or  indoor air sourced – Use information to select remediation and  cleanup levels

Conclusions • Empirical data/direct measurement works best • Soil gas at 10’ depth provides best soil data to  S il t 10’ d th id b t il d t t indoor air correlations • Attenuation  Attenuation – too variable to apply site wide too variable to apply site wide • Lithology and foundation type and condition play  large role in VI occurrence • Need early outdoor air sampling to establish  ambient air contribution and background levels • Concurrent multi‐media sampling helps define VI  Conc rrent m lti media sampling helps define VI behavior/sources Decrease source VOC levels/decrease VOC levels • Decrease source VOC levels/decrease VOC levels  in indoor air 

Contact and Document Information Contact and Document Information My contact information: Craig Rankine, Dept. of Ecology Vancouver Field Office, (360) 690‐4795 Vancouver Field Office, (360) 690 4795 [email protected] WA VI Guidance at: http//:ecy.wa.gov/programs/tcp/policies/VaporI ntrusion/vig.html