Implementation of a Strategic V l C f AhA pproach for

37 Pages·2010·3.46 MB·English

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Implementation of a Strategic
AApproachh ffor CCompllex VVapor
Intrusion Assessment at a
Large Military Facility
David W. Himmelheber
Emily H. Majcher, Paul Nicholson, Aron Krasnopoler,
TToodddd MMccAAllaarryy, RRoobbeerrtt EEttttiinnggeerr ((GGeeoossyynntteecc CCoonnssuullttaannttss))
Jennifer Harris (General Physics Corporation)
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JJoohhnn WWrroobbeell ((UUSS AArrmmyy,, UUSSAAGG AAbbeerrddeeeenn PPrroovviinngg GGrroouunndd))
Introduction to Vapor Intrusion
What is Vapor Intrusion?
•
Vapor intrusion (VI) is the transport of gas-phase
contaminants from the subsurface to indoor air
•
Typically originates from groundwater and/or soil
contamination --- volatile organic compounds (VOCs)
•
Exposures of contaminants to building
occupants are a major concern
••
RReellaattiivveellyy nneeww rreegguullaattoorryy eemmpphhaassiiss oonn
assessing VI risk
ITRC Vapor Intrusion Team logo; http://www.itrcweb.org/teampublic_Vapor.asp
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Site Background
Aberdeen Proving Ground (APG)
•
Established in 1917 in northwestern region of
Chesappeake Bayy
•
R&D, manufacture of military chemical agents
•
Portion of APG pplaced on NPL site in 1990
•
Canal Creek Study Area (CCSA)
• 700-acre pparcel
• Chemical manufacturing 1918 – end of WWII
• Current use is lab and pilot scale facilities
• Over 20 years of soil and groundwater investigations
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Site Background
CCSA Groundwater Impacts
(Courtesy of WESTON Solutions)
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Site Background
Key Project Challenges
•
Large number of buildings on Site (317)
••
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•
Co-mingled contaminant plumes
•
Complex hydrogeology below large site
•
WWoorrkkiinngg ccoonnssttrruuccttiivveellyy ttoo mmeeeett nneeeeddss ooff UUSS AArrmmyy
Federal, and State regulators
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P2
Site Background
Proposed VI Assessment Strategies
•
Initially Proposed Strategy
• Collect indoor air sampples from all buildinggs
•
Geosyntec
• PPrrooppoosseedd pphhaasseedd aapppprrooaacchh ffoorr VVII eevvaalluuaattiioonn
• Conceptual Site Model (CSM) development
• DDaattaa ccoolllleeccttiioonn ttoo rreeffiinnee CCSSMM
• Follow-up sampling for sub-set of buildings
• Evaluate mitiggation needs and opptions
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Slide 6
P2 Just a comment. I think we need to highlight that we took advantage of the amount of historical knowledge gained from previous
investigations and used this information to develop a phased approach. There was a lot of good data, it just needed to be complied
together and understood from a VI perspective.
PNicholson, 9/22/2010
COPC Identification
•
Develop list of COPCs based on:
• Calculated screening levels were developed based on risk
to building occupants
• DDettecttiion ffrequency anallysiis
•
COPC screeningg results
• 15 of 90 contaminants retained for groundwater
• 46 of 160 contaminants retained for soil
• COPCs include VOCs, SVOCs, PCBs, chemical warfare
material (CWM) degradation products, and mercury
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Conceptual Site Model Development
•• SSoouurrcceess ooff CCoonnttaammiinnaattiioonn
• Primary – Locations of Former Activities
•• SSeeccoonnddaarryy –– DDoowwnnggrraaddiieenntt CCoommiinngglleedd PPlluummeess
• Pathways
• Geology
• Hydrogeology
• Receptors (Building) Characteristics
• Buildings (Use, Occupancy, Foundation, HVAC)
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Conceptual Site Model Development
Historical 
analytical 
Sample Locations
data 
BBuuiillddiinngg RRDDMMPSS3 CCSSMM GGIISS SSttrraattiiggrraapphhyy
Inspections
Interviews
Building Locations Historical Activities
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