Shallow burial has been utilized in numerous countries worldwide for disposal of low-level radioactive wastes (1). At the Little Forest Legacy Site (LFLS) site near Sydney, Australia, low-level radioactive wastes were buried in closely-spaced unlined trenches between 1960 and 1968 (2). Similar to many overseas sites, there has been evidence of release of radioactive contaminants (including Pu) from the LFLS trenches (3). Several years of scientific work has been undertaken at the site to characterize radionuclide mobilization processes and assist in the selection of the preferred management option (3,4). Cutting edge techniques, such as synchrotron EXAFS (5), accelerator mass spectrometry (AMS) (6), and trace-level isotopic and REE analysis (7), have been applied in this research. The AMS technique has been applied to the measurement of anthropogenic radionuclides at LFLS, which are not usually present in Australian natural environments (e.g. 233U (6)). Also, a test trench facility has been constructed to support the in-field evaluation of remediation options, facilitate detailed studies of radionuclide mobilization processes and enable model parameterization (8). A multi-layer engineered cover was installed at the LFLS in late 2024, and the research has subsequently entered a new phase aimed at evaluating the effectiveness of this intervention. Such an assessment is now considered to be an essential component of post-remediation site management (1). The research during the current phase is specifically aimed at evaluating whether the installation of the cap has led to lower water levels in the legacy trenches, dampened the response to rainfall, or resulted in any impacts on radioactivity levels or the chemistry of groundwater. The research will involve extensive ongoing radionuclide measurements and further work with the experimental trench facility at the site. It is intended that the research will lay the groundwork for future monitoring and management of the site.