Light Non-Aqueous Phase Liquid Transmissivity Acceptance and Use by the Regulatory Community
Kimball, C.G., Hawthorne, J.M., Menatti, J.A., Rousseau, M.

The remediation of a petroleum hydrocarbon release often involves the removal of light non-aqueous phase liquids (LNAPL) from the subsurface. Historically, apparent NAPL thickness (ANT) has commonly been utilized as the metric for determining when LNAPL recovery was needed, and to signify the end-point to LNAPL recovery.

LNAPL transmissivity (Tn) provides a reliable metric for gauging LNAPL remediation. Tn is increasingly being used to quantify the feasibility of recovering LNAPL via hydraulic recovery methods, to optimize LNAPL recovery efforts, and to determine if LNAPL has been removed to the “Maximum Extent Practicable”. However, adoption of Tn to date by state environmental regulatory agencies has not been universal.

This paper presents the results of a “snapshot in time” (2016) survey indicating how Tn is being used by state regulatory agencies to make decisions regarding the feasibility of hydraulic LNAPL recovery. Regulatory agencies in the United States, Canada, Australia, and New Zealand were surveyed.

Primary Author/Presenter:
Greg Kimball
Senior Technical Manager
Minneapolis, Minnesota

J. Michael Hawthorne –GEI Consultants, Keller, TX, USA
John A. Menatti – Utah Department of Environmental Quality, Salt Lake City, UT, USA
Matthew Rousseau – GHD, Windsor, Ontario, Canada