Study by GSI Staff Documents NSZD at Hawaii Site with Basalt Geology

Thomas McHugh, Charles Newell, Brian Strasert, and Curt Stanley are authors on “Direct Aerobic NSZD of a Basalt Vadose Zone LNAPL Source in Hawaii” recently published in the Journal of Contaminant Hydrogeology. This ground-breaking study utilized two different measurement methods to document on-going Natural Source Zone Depletion (NSZD) at a site in Hawaii with Basalt geology. Both methods documented the occurrence of NSZD at the facility and the two methods yield estimates of the NSZD rate that agreed within a factor of 2. Soil gas samples indicated aerobic conditions throughout the vadose zone (oxygen >13%) and no detectable methane. These results indicate that NSZD occurs at this site through the direct aerobic biodegradation of LNAPL rather than the two-step process of anaerobic methanogenesis followed by methane oxidation at a shallow depth interval documented at other sites. This study serves to broaden the range of environmental settings where NSZD has been documented as an effective LNAPL remediation technology.

This journal article has been published open access. https://doi.org/10.1016/j.jconhyd.2020.103729

For more information intrusion please contact Tom McHugh at This email address is being protected from spambots. You need JavaScript enabled to view it..

For more information intrusion please contact Tom McHugh at This email address is being protected from spambots. You need JavaScript enabled to view it..