NATURAL SOURCE ZONE DEPLETION: WHAT IS IT AND WHERE DOES IT FIT INTO PETROLEUM NAPL SITE MANAGEMENT
Wednesday, May 13, 2020
Webinar was held on May 8th, 2020 - Hosted by GHD
Available on YouTube - https://youtu.be/RUdxFGSqDYI
Recent years have brought a new understanding of the potential magnitude and importance of natural LNAPL biodegradation (referred to as Natural Source Zone Depletion or NSZD) in the remediation and management of petroleum-contaminated sites as evidenced by contemporary guidance from the American Petroleum Institute (API) and the Interstate Technology & Regulatory Council (ITRC) in the U.S., and CRC-CARE in Australia. It is now understood that most of the petroleum degradation happening at LNAPL sites will be manifested through observable changes in LNAPL composition over time, soil gas content, and/or vadose zone temperature profiles. The assessment of NSZD is becoming a more standard consideration in LNAPL conceptual site model development and remedial decision-making, particularly since NSZD will represent the dominant LNAPL removal mechanism at many sites. This presentation will discuss the fundamentals of NSZD, provide an overview of the most commonly used methods to quantify it, and consider the different ways it may factor into the management of petroleum-contaminated sites. Case studies will be included from the U.S., Canada and Australia illustrating different ways NSZD rates were quantified, how NSZD rates compared to conventional LNAPL recovery system performance, and how NSZD fit into the overall LNAPL site management strategies.
Matt Rousseau is a Senior Associate Engineer and NAPL technical lead with GHD based in Windsor, Ontario, Canada. Since 2003, his work has focused on petroleum NAPL sites and the preparation of LNAPL Conceptual Site Models (LCSMs), the design of LNAPL site investigation programs, LNAPL mobility/recoverability/ stability assessments, NSZD evaluations, as well as the development of LNAPL remediation and management strategies with a focus on sustainable risk-based solutions. He co-founded GHD’s petroleum NAPL technical group and currently advises on NAPL projects globally. In this capacity, Matt regularly provides training related to LNAPL behavior, site characterization and remediation both internally to GHD staff and externally to clients, regulators, and other practitioners. He has also been involved in the development of LNAPL technical guidance documents in the U.S., Canada, and Australia, most recently as a member of the ITRC LNAPL Update Team (U.S.) and principal author of CRC CARE Technical Report 46 (2020) The role of natural source zone depletion in the management of LNAPL contaminated sites (Australia). Matt has both B.A.Sc. (1997) and M.A.Sc. (2000) degrees in Environmental Engineering from the University of Windsor in Windsor, Ontario, Canada, and is a licensed Professional Engineer (P.Eng.) in the Province of Ontario.