Rehabilitation Trust Fund
Abandoned mining lands refers to areas or sites of former mining activity for which no individual, company, or organisation can be held responsible. Such sites have also been called 'derelict' or 'orphan' mines. In recent years, the mining industry agreed to an increase in royalties, a portion of which was to be allocated to a Trust Fund, for the sole purpose of the repair of abandoned mining lands. A summary of recent works can be found in the MRT Annual Review. All current reports on works using funds from the Rehabilitation of Mining Lands Trust Fund can be accessed on the Rehabilitation Map.
Abandoned mine sites may contain hazards to human and animal life in the form of accessible adits, shafts and workings, and there may be associated pollution (such as acid drainage) from old workings and stockpiles. Visual degradation is an issue in some areas, even if the site is now not actively eroding. In some places, ongoing erosion can affect land stability, revegetation efforts and water quality.
These problems have arisen due to government requirements and operational standards being of a lower standard than are in use today. Modern mines are operated in accordance with 'best practices' techniques and government regulation of both exploration and mining is very strict. Bonds are held against both exploration and mining titles and these funds can be used for any rehabilitation, which is left outstanding by the operator.
A Trust Fund was established to fund rehabilitation of land affected by former mining or exploration activities and is defined in the Mineral Resources Development Act 1995 as:
(a) any money appropriated by Parliament for the purposes of this Part; and
(b) any money received from the sale of any building, machinery or property vested in the Crown under section 105(4); and
(c) any security deposit or part of a security forfeited by the Minister under section 198; and
(d) any other money received for the purpose of this Part; and
(e) any money the Treasurer directs to be paid into the Rehabilitation Trust Fund.
The Minister for Mines may: (Mineral Resources Development Act 1995, Section 180.)
(a) cause any abandoned mining land or land affected by former exploration activities to be rehabilitated; and
(b) enter into any contract relating to the environmental rehabilitation of any abandoned mining land or land affected by former exploration activities.
The fund was established after agreement with the Mining Industry to an increase in royalties, the proceeds of which would be used to repair abandoned mining lands.
A Committee has been established to provide advice to the Minister on the management of the Trust Fund. The committee is comprised of representatives from:
- Mineral Resources Tasmania (MRT),
- Department of Primary Industries, Parks, Water and Environment (DPIPWE),
- Environmental Protection Authority (EPA)
- Resource Management and Conservation (RMC)
- Parks and Wildlife Service (PWS)
- Sustainable Timber Tasmania,
- Concrete, Cement and Aggregates Australia (CCAA)
- Tasmanian Minerals and Energy Council (TMEC).
Abandoned mine sites present a number of challenges which are not common with other land restoration programs, such as:
- The absence of any planning for rehabilitation during the original operation.
- The degraded state of the sites - early miners did not conserve topsoil and sites are often completely bare with denuded expanses of regolith, bedrock and tailings emplacements, which present hostile environments for vegetation.
- Remaining soils are often contaminated and may be acidic after long term exposure to site pollution.
- Inadequate documentation of the operations may which present hazards, including unmarked workings, unstable embankments, and unexpected chemical contamination.
- Acidic water coupled with the uncertain extent of workings, make sealing workings to prevent further water entry or escape, difficult and sometimes, impossible.
- Mining and processing methods which have often spread the impact of activities beyond the precincts of the original site.
- The sites often have heritage and scientific significance.
- Sites may have become the habitat for native fauna and relict populations of native flora, sometimes as a direct result of mine disturbance.
- Most sites are isolated from major settlements so that in many cases cost recovery through subsequent sale of remediated land is not generally feasible.
- The presence of exotic noxious plants is also common.
These features complicate rehabilitation projects necessitating extensive and detailed planning prior to undertaking works.
The aims of rehabilitation are to:
- Remove risks to health and safety.
- Stabilise the site and reduce or remove the impact of erosion and mass movement.
- Where feasible maintain or increase the biological diversity of species in the vicinity.
- Remove or ameliorate sources of site contamination.
- Remove features limiting the beneficial use of the site and its surroundings.
- Improve the visual amenity of the site and its surroundings.
In many instances, work on the site may also require complementary off-site works to protect rehabilitation. It may also be necessary to limit the types of activities permitted on sites either for the short or long term to safeguard the integrity of rehabilitation.
Sites which are to be considered for rehabilitation must fit the following selection criteria:
1. The site is to be on Crown Land. Sites on private property will not be considered;
2. The site is to have been worked by private enterprise and not by Government or by Government instrumentality. Gravel pits previously worked by the Hydro Electric Commission, Sustainable Timber Australia, the Department of Main Roads etc. will not be considered;
3. The site must be abandoned, with the responsibility for rehabilitation resting with the Crown. Current liabilities of existing tenement holders will not be considered. However, work may be done on tenements where the tenement holder has been absolved of responsibility for pre-existing degradation.
Other factors to be considered include:
4. Threats to the safety or health of the public, stock or native flora/fauna;
5. Pollution impacts on adjoining properties or catchments;
6. Erosion or land degradation on/off site;
7. Loss of visual amenity;
8. Public concerns/complaints.
Sites which meet the first three points and most of the points 4-8 can be considered for rehabilitation. However, there are many abandoned mine sites and limited funds. Priorities are set for the sites which are suitable.
To set priorities for rehabilitation, a means for determining the degree of risk presented by a given site (environmental and safety) is required. Where practicable, this should be quantitative or semi-quantitative while still allowing for other factors to be used in final consideration of a site's eligibility for remediation. Such a method may entail an assessment of the likelihood of risks and the consequences utilising a risk assessment matrix to determine priority sites.
For the purposes of ranking abandoned mines, appropriate category definitions can be assigned. These can be applied to a number of selection criteria, including:
- Area affected
- Water pollution
- Erosion and sediment movement
- Cumulative Impacts - assessed on a catchment management basis.
- Risks to human health
- Public Safety
- Risk, depth of shafts;
- Extent of stoping and excavations;
- Ease of access;
- Population exposed.
- natural areas/National Park;
- orested land; productive forest;
- agricultural land;
- derelict farmland;
- acid drainage;
- siltation; and
- potential for weed infestation to spread.
- area of degradation;
- erosion, stable or actively degrading;
- loss of soil and vegetation;
- weed infestation.
- Stakeholder Consultation
- Proposed Works
- Current and proposed land use
- Staging of the proposed works
- Hours/days of operation
- Heavy traffic movements
- Potentially hazardous operations and/or movements
- Disposal of wastes
- Control of emissions
- Scientific and cultural information
Crown Land Managed by the Parks and Wildlife Service (PWS)
Crown Land Managed by Sustainable Timber Tasmania (SST)
The Trust Committee will meet quarterly. Progress reports on each individual project will be made quarterly and an annual report of Trust Fund activities will be produced.