Territory Stories

Assessment of the Jabiluka Project : report of the Supervising Scientist to the World Heritage Committee

Details:

Title

Assessment of the Jabiluka Project : report of the Supervising Scientist to the World Heritage Committee

Creator

Johnston, A.; Prendergast, J. B.; Bridgewater, Peter

Collection

E-Publications; E-Books; PublicationNT; Supervising Scientist Report; 138

Date

1999

Location

Alligator Rivers Region

Table of contents

Main report--Appendix 2 of the Main Report. Submission to the Mission of the World Heritage Committee by some Australian Scientists ... --Attachment A. Johnston A. and Needham S. 1999. Protection of the environment near the Ranger uranium mine--Attachment B. Bureau of Meteorology 1999. Hydrometeorological analysis relevant to Jabiluka--Attachment C. Jones, R.N., Hennessy, K.J. and Abbs, D.J. 1999. Climate change analysis relevant to Jabiluka--Attachment D. Chiew, F and Wang, Q.J. 1999. Hydrological anaysis relevant to surface water storage at Jabiluka--Attachment E. Kalf, F. and Dudgeon, C. 1999. Analysis of long term groundwater dispersal of contaminants from proposed Jabiluka mine tailings repositories--Appendix 2 of Attachment E. Simulation of leaching on non-reactive and radionuclide contaminants from proposed Jabiluka silo banks.

Language

English

Subject

Uranium mill tailings - Environmental aspects - Northern Territory - Alligator Rivers Region; Environmental impact analysis - Northern Territory - Jabiluka; Uranium mines and mining - Environmental aspects - Northern Territory - Jabiluka; Jabiluka - Environmental aspects

Publisher name

Environment Australia

Place of publication

Canberra (A.C.T.)

Series

Supervising Scientist Report; 138

Format

1 volume (various pagings) : illustrations, maps

File type

application/pdf

ISBN

642243417

Use

Copyright

Copyright owner

Environment Australia

License

https://www.legislation.gov.au/Details/C2019C00042

Parent handle

https://hdl.handle.net/10070/264982

Citation address

https://hdl.handle.net/10070/462402

Related items

https://hdl.handle.net/10070/462403; https://hdl.handle.net/10070/462400; https://hdl.handle.net/10070/462405; https://hdl.handle.net/10070/462406; https://hdl.handle.net/10070/462408; https://hdl.handle.net/10070/462409; https://hdl.handle.net/10070/462411

Page content

74 6 Long-term storage of mine tailings 6.1 Introduction In this chapter, issues related to the storage of tailings at the Jabiluka mine will be addressed. Since there have been a number of proposals for the storage of tailings, it is appropriate to clarify at the outset what the current proposal is. When ERA submitted the EIS on Jabiluka, the main thrust of the proposal was the Ranger Mill Alternative under which, as stated earlier in this report, all tailings produced from the milling of the Jabiluka ore would be deposited in the mined-out pits at Ranger. In the EIS, ERA also identified its original concept for the Jabiluka Mill Alternative. The intention at that stage was that, if milling at Jabiluka was the only option available to the company, about 75% of the tailings would be returned as a cemented paste to the undergound mine void and the remaining 25% of the tailings would be stored in a large tailings dam (total area about 55 ha) constructed on the land surface at Jabiluka. The intention was to rehabilitate the tailings dam in situ at the end of mining. The original JMA concept did not receive Government approval during the EIS process. By the time ERA submitted the Public Environment Report on the Jabiluka Mill Alternative, it had developed a different approach to tailings management. Under the revised plan, special pits would be excavated in the Kombolgie sandstone near the mill at Jabiluka and these would enable all tailings to be placed below ground from the outset and the site rehabilitation plan would include capping of the tailings pits with waste rock and final revegetation of the landform. This revised proposal was not accepted by the Commonwealth Government when it granted approval for the Jabiluka Mill Alternative to proceed. Rather, the Government required ERA to place all tailings in the mine void and in specially excavated stopes or silos in the vicinity of the orebody. ERA was required to prepare an amended proposal to the satisfaction of the Supervising Scientist and the Supervising Authorities prior to the granting of a licence for the export of uranium from the Jabiluka site. This amended proposal has not yet been received from ERA but detailed planning is underway. ERA has cooperated with the Supervising Scientist in the preparation of this review by providing information on its current plans, thus enabling the Supervising Scientist to assess the environmental impact that might arise. The proposal that is assessed in this chapter refers to the placement of 100% of the tailings from the processing of Jabiluka ore in the mine void and specially excavated silos in the vicinity of the mine void. The environmental issues that require assessment are twofold: (i) containment of the solid tailings so that they do not represent a long-term threat to the wetlands of Kakadu, and (ii) leaching of contaminants from the tailings, dispersion of the solutes in groundwater and the consequent potential impact on the wetlands of Kakadu. These issues are considered in the next two sub-sections. 6.2 Erosion of tailings in the long-term The location of the mine void and the approximate location of the tailings silos as currently planned by ERA are shown in figure 6.3.3 The highest part of the mine void is about 80 m