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| Outflow | Share of total
discharge |
|
|---|---|---|
| ML/d | % | |
| Pastoral bores
Flowing bores a |
130 | 29 |
| Springs
Dalhousie Others |
54
12 |
12
3 |
| Olympic Dam/Roxby Downs | 15 | 3 |
| Gas/Petroleum | 22 | 5 |
| Vertical leakages b | 217 | 48 |
| Total | 450 | 100 |
a Includes towns and homesteads, except Roxby Downs and Moomba.
b Difference between discharge and estimated recharge for the
South Australian portion of the Great Artesian Basin.
Source: Mines and Energy South Australia (personal communication, December 1995).
Reprinted from: Lake Eyre Basin - an economic and resource profile of the South Australian portion, ABARE Research Report 96.1, 1996, 48
The South Australian Government has informed the Committee that observed drawdowns in water pressure and decline in spring flows are generally less than originally predicted and within the accepted level of impact. "As was predicted in the EIS [environmental impact statement] (1982), two springs have ceased to flow. However, in some areas the rate of drawdown was greater than expected and approached the limits imposed by the Special Water Licence. In addition the reduction in flows at some springs (notably Bopeechee) was greater than anticipated. These effects were found to be due in part to geological structures not identified at the time the initial modelling took place." (S 109, 9)

Great Artesian Basin, South Asutralian Section - Mound Springs
The South Australian Government report:
The water abstraction regime has been modified to minimise these effects. In addition reinjection of water is being undertaken to raise the piezometric head in order to reverse the decline in Bopeechee Springs, and the development of Borefield B was accelerated in order to reduce the overall abstraction rate from Borefield A. (S 109, 9)
The South Australian Government has stressed that these impacts were detected by the monitoring program and that appropriate remedial action was initiated to prevent any long term effects on the Great Artesian Basin and particularly the local mound springs beyond those predicted in the environmental impact statement. In addition, WMC have implemented an extensive water conservation policy which is aimed at minimising the amount of water extracted from the Great Artesian Basin (S 109, 9-10).
According to the Australian Conservation Foundation, " [t]he excessive quantities of water required by the mine and the positioning of borefields is resulting in long-term degradation of mound springs as well as serious depletion of groundwater tables" (S 81, 1.1.2, 5).
The Conservation Council of South Australia/Friends of the Earth Nouveau submission expressed a similar fear that because the springs are shallow and often small in area they will without an adequate flow of ground water rapidly dry up and be irreparably damaged (S 92, 12).
The Committee's conclusion is that concerns about the water being drawn from the Great Artesian Basin are insufficiently focussed to lead to any firm recommendation other than that the monitoring program referred to by the South Australian Government should be maintained.
The Conservation Council of South Australia/Friends of the Earth Nouveau stated that because pastoralists in the area are now being charged for water drawn from the Great Artesian Basin, there should also be a charge for water drawn for use in the Olympic Dam Operation. (S 92, 19). Enquiries disclosed that no such charges are being levied.
A second justification for a charge on water from the Great Artesian Basin lies in cost recovery user pay principles under the National Competition Policy. A purpose of this policy is to build in an economic incentive to minimise water usage and consequent environmental impact (S 92, 19).
The Committee does not agree. The water does not come to WMC without cost. The plant needed to collect the water and pipe it to the mine site costs in excess of $100 million. Although the water is also used in Roxby Downs, no other body makes any contribution to the costs. On the basis of evidence presented to it on this occasion the case for departing from the policy of non-discrimination in charging for water from the Great Artesian Basin has not been made.
For areas where charges are levied for water, for example for reticulated water in metropolitan and more closely settled rural areas, the principal purpose of those charges is to meet the capital and recurrent costs of the reticulation system.
As already recorded, WMC has invested $100 million in infrastructure to draw water from the Great Artesian Basin. In other words, it is meeting the full cost of drawing its water supply and of monitoring the impact of its water usage to preserve the viability of the Basin and its environmentally sensitive aspects.
Included in the infrastructure are facilities for continuous long-term modelling providing the capacity to reforecast the impact of pumping and adjust it as required to avoid any detrimental impact.
From the first phase of uranium mining in Australia there are several abandoned mines: Radium Hill; Rum Jungle; various mines in the South Alligator Valley; and Mary Kathleen. Rehabilitation of these mines was never properly planned during the life of the mine, nor was finance organised as part of the business.
Nabarlek, the first mine of the second phase, is now in the process of rehabilitation. Rehabilitation was planned even before mining commenced. It represents a very different approach to mining.
The purpose of this part of the chapter is to review rehabilitation practices and activity.
The South Australian Government has stated that "only minimal rehabilitation of the wastes was undertaken" when the mine at Radium Hill was closed. Tailings from the upgrading process undertaken at the site remained as a "pile". "Although this material consisted mainly of mineralised sands and mica, with a low radionuclide content, it was unprotected from wind and water erosion." (S 109, 14)
In the last decade, Radium Hill wastes have been covered with approximately 3 metres of soil and revegetated. Other wastes such as drill cores were collected and buried in the tailings pile.
When the mine was in operation, uranium concentrate was taken by railway to a treatment plant at Port Pirie where the uranium was extracted. The tailings containing the bulk of the residual radioactivity in the ore remained in clay lined dams at Port Pirie. These dams are on a tidal swamp and were threatened with inundation during extreme tides. The tailings were uncovered with no control over dust raising or radon emission.
These tailings have been covered with about 2 metres of slag (from the adjacent smelter) and topsoil, and have been revegetated. The site generally has been protected from high tides by extensive mounds of slag.
An independent consultant recently inspected both sites and considered them, subject to minor repairs, to be in good condition. (The above account is based on the South Australian Government submission, 109, 14-5; see also S 92, 10).
The Committee is not convinced, on the evidence before it, that rehabilitation and remedial work has been satisfactorily completed. It recommends a full public evaluation of the work as soon as possible and that the sites be reappraised at intervals of not more than two years.
Between 1954 and 1964 there were 13 uranium mines in the upper reaches of the South Alligator River. These mines are spread in a belt about 2 km wide and 20 km long from Coronation Hill in the southeast to near UDP Falls ("Gunlom") in the northwest. (Another mine at Sleisbeck in the headwaters of the Katherine River was worked in 1957. Ore from this mine was processed at Rum Jungle.)
Most of the ore from these mines was processed at Moline, although some was processed in a small mill built on the El Sherana-Gunlom road.
There was little clean-up when operations ceased.
The tailings dumps at Rockhole and Moline were poorly constructed and over time radioactive tailings escaped into the drainage system.
At Moline, tailings had travelled more than 10 km downstream of the breached containment structure. The containment was poorly confined and failed after only one wet season following abandonment of the mine in 1972.
At Rockhole, water carrying radioactive tailings had flowed into the adjacent South Alligator River.
In 1992 the Supervising Scientist, in consultation with the Australian Nature Conservation Authority and the Department of Primary Industries and Energy, supervised a program of hazard reduction works in the valley. These works consisted of collapsing or barring entrances to adits; fencing around pits; and burying contaminated wastes of all types at newly constructed containment sites.
Tailings from the Rockhole area were removed and reprocessed at Moline to extract gold and then placed in the tailings containment structure at Moline.
After scraping, the Rockhole tailings area was ripped and revegetated. No new soil was imported into the area.
Gamma dose rate surveys were carried out when work was completed to ensure that radiation levels had been brought below the required levels.
The public dose rate from radiation was reduced to below the public limit, thus enabling the area to be managed as a national park without the need for serious restrictions on visitor access.
(Paraphrase from Supervising Scientist submission, 85, 6-7).
Moline was the location for tailings derived by processing ore from a series of base metal operations nearby and uranium/gold ore from the South Alligator area.
The tailings were inadequately deposited and about 25 per cent were carried away, eventually to the Mary River flood plain.
The Supervising Scientist states: "No evidence of permanent environmental impact arising from the tailings has been noted. This may partly be due to the total drying of the creek system each dry season, and the difficulty in determining impacts in such a naturally variable ecosystem." (S 85, 7)
According to the Supervising Scientist: "The tailings repository radiation protection was capped by contractors [Pacific Territory Department of Mines and Energy in 1991-92 and covered with a rock mulch as erosion protection. A radiation survey was undertaken at the under the supervision of the end of rehabilitation work to ensure Gold Mines] Northern that targets had been met." (S 85, 7)
The cost of rehabilitation was recovered by the company through retreatment of tailings for gold.
(Based on Supervising Scientist submission, 85, 7; and Northern Territory Government submission, 100, 7).
This mine was rehabilitated by the company, in which Rio Tinto Mining Co of Australia Ltd had a majority of shares, according to the code of practice on the mining and milling of radioactive waste.
According to Canning Resources, a subsidiary of Conzinc Riotinto, rehabilitation was provided for in a full environmental impact study undertaken before the mine reopened in 1976. Canning Resources state: "Mary Kathleen then became the site of Australia's first major rehabilitation project of a uranium mine, which was completed at the end of 1985 at a cost of some $19.5 million. In 1986 this work won an award from the Institution of Engineers Australia for environmental excellence." (S 65, 12)
The Australian Conservation Foundation commented: "There is a view that at the time of the mine's closure the rehabilitation would not have met with the standards of the OSS. The tailings dam was clearly leaking and it would be a matter of good luck rather than good management that there would not be adverse environmental impacts arising from the leakage" (S 81, 1.3, 7).
Ore from five small mines in this area near the Queensland border was trucked more than 1800 km to Rum Jungle for processing.
According to the Supervising Scientist, "[e]nvironmental impacts were small as the workings were mainly small shafts and shallow open cuts . . . radiation from old stockpiles was potentially hazardous." (S 85, 9)
Remedial and hazard reduction works have been undertaken according to a plan drawn up by DPIE in 1988, work being completed as funds have become available. The Supervising Scientist has commented: "Completed sites have achieved levels of gamma radiation low enough to permit public access for lengthy periods, but not permanent occupancy."
(S 85, 9)
In two decades of mining and milling, of copper as well as uranium, some 600,000 tonnes of tailings were produced and spread over about 31 ha. Supernatant liquid, which also contained some suspended tailings, drained over a spillway and thence flowed into the Finniss River. Research on the Finniss River has shown that the main agent causing the damage was copper. There was also some wind dispersal of tailings.
Containment of pollutants was not part of an initial clean-up organised in 1977.
In a joint Commonwealth/Northern Territory Government hazard remediation program completed in 1986, tailings and contaminated soil were placed in the Dyson's Open Cut. The Supervising Scientist has observed, citing Verhoeven:
No special preparation of the pit was undertaken prior to placement of the tailings. The pit was then sealed with waste rock and a final soil cover and vegetated. The tailings dam site was covered with topsoil, surface drainage was installed and the whole area revegetated. (S 85, 7-8)
Owing to the sulphides in the ore bodies, these measures were unsuccessful and were the main cause of the severe environmental impact to the aquatic ecosystem of the Finniss River for 10 or more kilometres downstream. It is considered that environmental problems derived from the copper rather than uranium.
Another rehabilitation program was considered "generally successful, and life has returned to the Finniss River." (S 85, 8)
The "sustainability of the site is still not certain" (S 85, 9).
The copper mine at Rum Jungle Creek South has also been the subject of a remedial action program, as have other small mines in the district.

Rum Jungle - Abandoned and neglected until recently
Nabarlek is the first mine to be opened in which rehabilitation was part of the original planning. A benefit of addressing rehabilitation as part of the planning and operation of the mine is a substantial reduction in cost. According to Queensland Mines, the owner, "the cost of the work has been less than one quarter of rehabilitation projects costs (per unit uranium produced) at other uranium mines in recent times." (S 78, 3)
According to Queensland Mines, techniques in rehabilitation included in-pit tailings disposal, tailings preconsolidation, holistic rehabilitation planning, revegetation, use of Caro's Acid, induction and training, environmental monitoring programmes, water management and radiation safety. (S 78, 8)
The total cost of decommissioning was about $8 million.
Nabarlek was the subject of examination by the Supervising Scientist throughout the life of the mine. There was one "major" incident during a cyclonic storm in March 1981. "Because of the origin of the runoff water and the dilution from the storm, it was considered that no environmental degradation resulted." (S 85, Attachment C)
The Supervising Scientist has described other incidents as "all minor and of little consequence." In all, fifteen incidents or unusual occurrences are recorded in the annual reports of the Supervising Scientist" (see Appendix 2.10 for a list) (S 85, Attachment C).
The Supervising Scientist has also noted:
Other matters causing effects on the environment include the tree death in the Forest Irrigation Area. Leaching from this area has left a chemical signature in a small creek downstream. Investigations by ERISS are continuing so as to determine if there was any effect on the fish in this creek.
The introduction of some weeds can also be ascribed to the establishment of the mine. Weed species include Mission grass Penisetum polystachion; Grader grass, Themeda quadrivalvis and Hyptis, Hyptis suavalens. The company has pursued an active weed monitoring and control program which is continuing into the post rehabilitation period. (S 85, Attachment C)
The Supervising Scientist's appraisal is as follows:
The standard of the rehabilitation works is world class and a good example of what modern mine environmental engineering can achieve. The tailings were deposited in the pit during operations. All radioactively contaminated material was placed above the tailings in the pit and then covered with waste rock. All structures have been removed or demolished (other than those transferred to the traditional owners, which are in the process of being dismantled and/or relocated). The disturbed ground was been prepared, seeded with local tree species and fertilised in late 1995 and significant grass and tree growth is already evident. Assessment of the adequacy of rehabilitation and revegetation is to be made by an independent expert chosen jointly by the mining company, the Northern Land Council, and government authorities. (S 85, Attachment C, Summary)
The Northern Land Council have appraised Nabarlek rehabilitation in the following terms:
The goals of rehabilitation were formulated in consultation with the Aboriginal landowners, and the rehabilitation design was scrutinised by the NLC. Aboriginal landowners of the minesite made several inspections of developments during the decommissioning process, and continue to do so.
The physical structure of the Nabarlek Uranium Mine has largely disappeared. Replacing the pit, plant, stockpiles and evaporation ponds is a low relief area with a surface of waste rock and soil. Grasses, young shrubs and tree seedlings are already covering much of this surface, however the success of the rehabilitation has yet to be determined. QMPL will be released of their responsibility for maintenance of the site when the NLC and Aboriginal landowners are satisfied that they will be left with a landscape that blends into the surrounding environment, and will not be a liability to them or their descendants.
Nabarlek has continually been subject to less scrutiny than the Ranger Uranium Mine by government, environmental groups and the general public because it lies within Arnhem Land and is less accessible. The fact that environmental management of the mine has been to such a high standard is due in part to the corporate policy of QMPL, but largely due to the fact that high standards of environmental management and adherence to environmental requirements were contractually enforced by the NLC. (S 42, 7)
The Committee had to reply on evaluations by the Supervising Scientist.
Unfortunately the Australian Conservation Foundation, for example, commented only briefly on rehabilitation at Nabarlek, merely noting that the Northern Territory Government has yet to cancel the financial arrangement to cover the costs of rehabilitation because "a benchmark for successful rehabilitation has never been set" (S 81, 7, citing Dennis Schulz, The Bulletin, February 1996).
Subsequently, in evidence, Mr Michael Krockenberger, Campaigns Director, ACF, told the Committee: "I do not think . . . you can draw any conclusions from Nabarlek yet; Nabarlek has not even been completed in terms of its rehabilitation (23 August 1996, 318).

Narbarlek - Planned and monitored