Six Australian case studies of LNAPL NSZD rates using multiple methods, and comparing findings with conventional active recovery efforts

CRC Care, an independent organization dedicated to the remediation of contaminated soil, water, and air; published on March 2020 its technical report no. 47 about a comparison of NSZD to active remedies on six LNAPL contaminated sites.

The objectives for the research program were: i) to measure NSZD rates in Australia, and compare them to LNAPL removal rates, ii) develop a guidance document for methods to measure NSZD rates, iii) document the role of NSZD in the management of LNAPL-contaminated sites, and iv) involve stakeholders in this process to manage expectations of remedial goals.

One of the main conclusions of this study was that it is challenging to find appropriate reference unimpacted locations (i.e., background), required by all methods, except E-Flux passive soil gas flux traps.