Global Director Technical Services, CETCO
Jim Olsta is Global Director of Technical Services for CETCO. Mr. Olsta is a professional engineer with 40 years of experience in the environmental field. He has a Master of Science degree in environmental engineering from the University of Illinois. Mr. Olsta has launched several environmental products for waste containment, remediation and vapor intrusion mitigation. He has authored numerous papers in professional journals. Mr. Olsta is task group leader for ASTM D18.21.07 Groundwater and Vadose Zone Remediation Technologies.
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Passive Vapor Intrusion Mitigation at Brownfield Sites
Vapor intrusion into buildings on brownfield sites is a major concern for developers. A passive vapor intrusion mitigation composite barrier has been developed. The composite barrier includes both a geomembrane and a spray-applied layer. The geomembrane has multi-layers consisting of outer polyethylene layers and an inner layer of co-polymer ethylene and vinyl alcohol (EVOH). EVOH is known for its low gas diffusion properties. The spray- applied asphalt-latex layer is critical at pipe penetrations and vertical attachments to prevent short circuiting through these details. Laboratory bench-scale experiments were conducted on samples of the composite barrier. The samples were suspended in borosilicate chambers. Below the barrier was a layer of solvent (PCE or TCE). Solvent vapors diffusing through the barrier were captured by exit tubing filled with granular activated carbon (GAC). Solvent vapors adsorbed onto the GAC was measured. The barrier was exposed to the solvent vapors until steady state was reached (over two years). The diffusion coefficient for the composite barrier was then calculated using Fick’s Law. The laboratory setup and test data will be presented.