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In this webinar we were pleased to have special guest speaker Sigrida Reinis, PhD, PE, Senior Associate at Langan Engineering and Environmental Services Inc. Her presentation discussed a case study in air quality data control. She was joined by Hieu Nguyen, Principal Engineer at Land Science, who discussed innovative vapor intrusion mitigation system technologies.

Learn the following in this free webinar:

  • Issues surrounding detectable levels of contamination that can adversely affect data quality due to SUMMA canisters
  • A vapor intrusion mitigation system (VIMS) case study where inexplicable anomalies were observed in the monitoring data set
  • A numerical approach presented identifying anomalous data developed by Langan to address this problem

  • In recent years, both anecdotal evidence and rigorous research have indicated that even individually certified SUMMA canisters may arrive at a project site with detectable levels of contamination that can adversely affect data quality. Research (by others) indicates that while approximately three percent of duplicate groundwater samples have laboratory analytical results that differ significantly from those of the primary sample, with whole air samples this inconsistency increases ten-fold. This presentation will focus on one site in the San Francisco Bay Area at which a passive sub-slab vapor intrusion mitigation system (VIMS) was installed during construction and whole air sampling, for the purposes of VIMS performance monitoring, began in the fall of 2016. After several years of regular monitoring, inexplicable anomalies were observed in the data set, and the frequency of anomalies increased over subsequent monitoring events. In response, Langan developed a numerical approach to identify anomalous data that was subsequently applied to the data sets. This presentation will provide a brief project background, describe the QC approach, discuss the ramifications to the project of the data anomalies and their identification, and describe the changes to the sampling program that will be implemented in the immediate future.

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    About the Presenters:

    REGENESIS Remediation Solutions Sigrida Reinis, PhD, PE
    Senior Associate, Langan
    Dr. Reinis is a Senior Associate with Langan Engineering and Environmental Services and lives and works in Oakland, California. She holds Bachelor of Science, Master of Engineering, and doctoral degrees in Civil Engineering from the University of California at Berkeley. Sigrida is a Professional Engineer in the State of California and a licensed General Engineering Contractor in California. With over 25 years of design and construction oversight experience, Sigrida is the technical leader of the gas and vapor intrusion mitigation and monitoring practice for Langan in California, supporting projects ranging from ¼-acre brownfield redevelopments for affordable housing to landfill redevelopments for multi-tower life science campuses. In addition, Sigrida leads the probabilistic cost estimating and decision analysis practice for Langan nationwide. She also has prepared and provided peer reviews of the full spectrum of technical documents related to the remediation of redevelopment of brownfield sites and municipal solid waste landfills, and has provided litigation support and expert witness services for both construction and environmental engineering projects.

    REGENESIS Remediation Solutions Hieu Nguyen
    Principal Engineer, Land Science
    Hieu Nguyen is the Principal Engineer of the Land Science division of REGENESIS, Inc. In his role, Hieu oversees product implementation at construction sites and provides technical support to regional and district managers as well as Land Science clients. Hieu offers over fifteen years of experience supporting vapor intrusion mitigation system designs, specifications and installations across United States, Canada and Australia. He is also an active member of the ITRC Petroleum Vapor Intrusion task group, AICHE and ASTM D04 Asphalt Emulsions Tests and Specifications. Prior to joining Land Science, Hieu worked as a product manager and technical engineer for a leading spray-applied asphalt latex gas barrier manufacturer. Hieu earned a Bachelor of Science degree in Chemical Engineering from University of Idaho in Moscow, Idaho.