Quantitative Passive Vapor Sampling with the Waterloo Membrane Sampler

Isaac B. Roll, Ph.D., P.E.Senior Staff EngineerGeosyntec Consultants

Friday, February 24, 2017

Abstract: Vapor sampling is a useful tool for evaluating a variety of environmental concerns, including indoor air quality, fugitive emissions, equipment and process integrity, and vapor intrusion, as well as for remedial investigations to locate volatile organic compound (VOC) sources in the subsurface. A variety of vapor sampling methods are available; these may take whole-air samples or sorbed samples of the constituents of interest. Results may be qualitative or quantitative, and time-discrete or time-integrated. As a class, passive samplers have been the subject of much contemporary research because they offer benefits in sensitivity, economy, and simplified field work. In many applications (e.g., personal dosimeters), passive samplers have been used to provide quantitative results for decades. In others (e.g., soil vapor or sub-slab sampling) only qualitative results were available until recently, due to effects such as analyte starvation. The Waterloo Membrane Sampler, a passive vapor sampler, is an example of a recently developed device that is capable of quantitative soil vapor sampling. A brief review of vapor sampling theory and methods is presented, as well as a discussion of example applications.

Bio: Dr. Roll has experience planning and executing environmental engineering field activities in Arizona and California, including permitting, communication with public and private stakeholders, development of health and safety plans, selecting and managing subcontractors, and performance of a variety of investigative sampling techniques for water and vapors. He has published and presented on characterization topics including data quality effects of passive sampler designs, tidal effects on contaminant concentrations, and novel sampling methods for air and water contaminants. In addition to coordinating site characterization activity, Dr. Roll provides engineering support for a number of remediation projects, including a 1,000 gpm capacity fluidized bed bioreactor system and liquid- and gas-phase granular activated carbon systems of a variety of sizes and configurations.