4.0 Environmental Assessment

4.1 Water Management

Additional information was requested from Ashton Mining Limited in regard to   their proposed water management plan and this was provided and assessed within   the PER assessment period.

Key issues associated with the surface water runoff are erosion and sediment   control, particularly during the initial pre-stripping and clearing for the   dumps and pits and during dewatering of the mine pits. Sediment dams and erosion   control structures will be constructed downslope of all waste dumps and mining   pits to manage these issues.

Concerns relating to the mine water management system focus on containment of   water from the mining and waste dump runoff and the potential effects on surface   water.

Designs, schedules and monitoring proposals for the proposed water management   systems will be required prior to the commencement of the project.

Recommendation 2

Ashton Mining Limited should prepare a water management plan which   includes:

This water management plan should be incorporated into the   Environmental Management Plan and reviewed on a routine basis by the Department   of Mines and Energy.

4.2 Weed and Feral Animal Management

The noxious weed Xanthium occidentale (Noogoora burr) occurs in the   vicinity if the access road, particularly along watercourses. Appropriate   management will be required to ensure that weed seeds are not transported during   road construction and maintenance.

The project area itself has been relatively isolated due to its location and   lack of access and as such safeguards need to be implemented to prevent the   incursion of introduced and problem floral species into the area.

One of the prime ways of weeds entering a relatively weed-free area is on   earth moving equipment, or in soil, fill, sand, gravel or other building   materials. The disturbance occasioned by these activities also enable weed   establishment and spread.

The cane toad, Chaunus marinus is found in numbers in the   McArthur/Glyde Rivers region. Although the cane toad has become abundant in a   range of habitats in the region appropriate management will be required to   prevent the transportation of the toad to areas currently free from infestation.

Recommendation 3

In line with the Northern Territory Weed Management Strategy, 1996 -   2005, Ashton Mining Limited should design a weed management plan covering the   mine site and access corridor to prevent the introduction and spread of weeds.

Ashton Mining Limited should implement a strict inspection program to   prevent the transportation of cane toads from the area.

This information should be incorporated into the Environmental   Management Plan and reviewed on a routine basis by the Department of Mines and   Energy.

4.3 Rehabilitation

The PER identifies the construction and utilisation of two tailings dams for   coarse and fine tailings respectively. There is the possibility that if the fine   tailings are very fine, as is likely, these may be difficult to rehabilitate,   and Ashton should investigate the possible need for discharge of thickened   tailings. Additional information will be required prior to approvals being given   for construction.

Recommendation 4

Ashton Mining Limited should prepare detailed tailings dam designs   and tailings characterisation.

This information should be incorporated into the Environmental   Management Plan and reviewed on a routine basis by the Department of Mines and   Energy.

The rehabilitation strategy proposed in the PER is considered adequate at   this time. During the development and operation of the mine, a detailed   rehabilitation plan will be developed through rehabilitation trials and on-site   experience.

Recommendation 5

Rehabilitation trials should be undertaken to develop a final   rehabilitation strategy.

This information should be incorporated into the Environmental   Management Plan and reviewed on a routine basis by the Department of Mines and   Energy.

4.4 Heritage

A number of archaeological sites were identified near the proposed mine site   and along the access road. The proposed development has the potential to impact   on at least two of these, Catfish Hole 1 and Catfish Hole 2.

With respect to Catfish Hole 1 the preferred option is to realign the track   and to construct a temporary fence to avoid damage by machinery operating in the   area.

In regard to Catfish Hole 2 the PER identifies two protective strategies,   these recommendations are supported and the proponent is strongly urged to adopt   these measures.

Heavy machinery should be strictly prohibited from operating within the   vicinity of archaeological sites.

Some form of fencing may be required to ensure that these sites are not   inadvertently disturbed.

Recommendation 6

Ashton Mining Limited should, with respect to Catfish Hole 1, realign   the access road and construct a temporary fence.

With respect to Catfish Hole 2, Ashton Mining Limited should fence   the northern margin of the site and erect warning signs to prevent disturbance   and damage.

This information should be incorporated into the Environmental   Management Plan.

4.5 Environmental Monitoring

Ashton Mining Limited has outlined in the PER a proposed sampling and   monitoring program. All components of the monitoring program will be implemented   at the commencement of operations, including access road construction. Baseline   surface water quality and groundwater level monitoring will be completed before   the commencement of mining operations.

Recommendation 7

Ashton Mining Limited should complete and submit a baseline and   operational monitoring programme, including identified parameters and   thresholds, in an Environmental Management Plan.

Ashton Mining Limited should operate in accordance with the approved   plans, with these plans being reviewed by the Department on a regular basis.

4.6 Other Issues


The possibility of social impact on the township of Borroloola and   surrounding area, by the construction and operational workforce, will be   minimal. Given the isolation of the site, 130km by road, the fly in fly out   staffing strategy and the accommodation of all construction and operational   staff on-site (all employees and contractors will remain on site during their 14   day roster period).

Flora and Fauna

Several species of conservation significance were identified in both the   project area and proposed access road corridor. The areal extent of the project,   however, is small compared with the surrounding habitat, and if the proposed   conservation measures are adhered to, there should not be a significant lasting   effect on the local flora and fauna.

The Environmental Management Plan needs to consider measurers to manage flora   and fauna of conservation significance. Additional surveys may be required to   determine the relevant management strategies.

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