eriss research summary 2011-2012

Supervising Scientist Report 204
RA van Dam, A Webb & SM Parker (eds)
Department of Sustainability, Environment, Water, Population and Communities, 2013
ISSN 1325-1554
ISBN-13: 978-1-921069-21-5

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Preface

The Environmental Research Institute of the Supervising Scientist (eriss) is part of the Supervising Scientist Division (SSD) of the Australian Government’s Department of Sustainability, Environment, Water, Population and Communities (SEWPaC). eriss provides specialist technical advice to the Supervising Scientist on the protection of the environment and people of the Alligator Rivers Region (ARR) from the impact of uranium mining. Its major function is to conduct research into developing leading practice methodologies for monitoring and assessing the impact of uranium (U) mining on water and air (transport pathways) and soil, and on the bushfoods that are consumed by the local Indigenous people. This research spans the operational, decommissioning and post rehabilitation phases of mining.

eriss also applies its expertise to conducting research into the sustainable use and environmental protection of tropical rivers and their associated wetlands, and to undertaking a limited program of contract research on the impacts of mining elsewhere in the north Australian tropics.

The balance and strategic prioritisation of work within the uranium component of eriss’s project portfolio are defined by Key Knowledge Needs (KKNs) developed by consultation between the Alligator Rivers Region Technical Committee (see ARRTC membership and function in Appendix 2), the Supervising Scientist, Energy Resources of Australia Ltd (ERA) and other stakeholders. The KKNs are subject to ongoing review by ARRTC to ensure their currency in the context of any significant changes that may have occurred in U mining related activities and issues in the ARR.

Not all of the KKN research areas (Appendix 3) are able to be covered by eriss, since not all of the required disciplines are available within the Institute. To address these particular gaps, collaborative projects are conducted between eriss and researchers from other organisations, and consultants are commissioned by eriss and others to undertake specific pieces of work. For example, KKN projects related to detailed hydrogeology or tailings management on the Ranger lease are conducted and reported separately by consultants engaged by ERA. A more complete picture of the scope of research work that is conducted by all parties can be obtained by referring to the minutes that are produced for the meetings of ARRTC.

This report documents the monitoring and research projects undertaken by eriss over the 2011–12 financial year (1.7.11 to 30.6.12). The report is structured according to the five major topic areas in the KKN framework, noting that this year there are no papers for Jabiluka or Nabarlek.

  1. Ranger – current operations
  2. Ranger – rehabilitation
  3. Jabiluka
  4. Nabarlek
  5. General Alligators Rivers Region

eriss continued its chemical and biological off-site monitoring programs for assessing impacts from the current operations at Ranger. Research associated with current operations continued its focus on water quality issues. The discrepancies in snail egg production between the downstream site relative to the upstream site for the Magela and Gulungul creek in situ toxicity monitoring programs was further studied. Snail egg production was found to be related to water temperature and electrical conductivity (EC) in a complex, interacting relationship. However, the physiological mechanism underpinning these observations is not yet understood. Other research of note included the derivation of annual solute load budgets for Gulungul Creek upstream and downstream of Ranger using the continuous monitoring data obtained over the past seven wet seasons (2005–06 and 2011–12), and the commencement of an assessment of the toxicity of manganese to local freshwater species.

Research related to rehabilitation at Ranger is a key focus at eriss. The trial landform studies continued in 2011–12, with a focus on the monitoring of erosion products and water chemistry in runoff from two of the four erosion plots. The bedload being exported from these plots continues to decline linearly with time, with the 2011–12 wet season data showing, for the first time, the effects of the developing vegetation on reducing the rate of erosion. Radon exhalation flux densities from the trial landform are also being assessed. Research into the development of closure criteria continues to be a focus area, particularly in relation to billabong water quality and terrestrial vegetation.

Jabiluka is in long-term care and maintenance and the current work of the Supervising Scientist is focused on maintaining a routine continuous monitoring program for flow and electrical conductivity downstream of the formerly disturbed area. Uranium Equities Ltd continues to pursue exploration activities on the Nabarlek lease. Environmental monitoring and assessment for this site is being conducted via Mining Management Plans submitted by the company to the Northern Territory Government.

Significant 2012–13 work planning activities were undertaken during 2011–12, as a result of ERA announcing an increased focus on determining closure timelines and associated knowledge needs. The outcomes of this process will be reflected in the program of research and monitoring presented in the 2012–13 Annual Research Summary.

Key non-uranium mining related external activities for 2011–12 centred around two large government-funded programs: (i) the National Environmental Research Program (NERP) Northern Australia Hub, and (ii) the current revision of the Australian and New Zealand Guidelines for Fresh and Marine Water Quality. Involvement in the NERP Hub focused on the acquisition and analysis of LiDAR data for the Alligator Rivers Region floodplains, for which the details are provided in a related core research project on the use of LiDAR data (see ‘LiDAR capture for the Alligator Rivers Region, KKN 2.2.1 Land design, p116). Details of the involvement in the Water Quality Guidelines revision are provided in the Supervising Scientist 2011–12 Annual Report.

Three maps (following this Preface) provide the regional context for the locations that are referenced in the research papers. Map 1 shows Kakadu National Park and the locations of the Ranger mine, Jabiluka project area, the decommissioned Nabarlek mine, and the South Alligator River valley. A schematic of the Ranger minesite is provided for reference in Map 2. Map 3 shows the locations of billabongs and other waterbodies used for the aquatic ecosystem monitoring and atmospheric and research programs for assessing impacts from Ranger mine.

For additional information, readers are referred to the annual publications list (Appendix 1) that details all of the material published, and conference and workshop papers presented, by eriss staff in 2011–12.

Finally, I would like to take the opportunity to acknowledge the former Director of eriss, Dr David Jones, for his tireless and highly committed efforts at guiding the Institute’s research program and improving its business systems during his tenure.

Dr RA van Dam
Acting Director, Environmental Research Institute of the Supervising Scientist