Want to know more about our exploration processes and environmental protections?
Our Exploration Licences are granted by the Victorian state government, usually for a period of five years. Mineral exploration is strictly regulated under the Mineral Resources (Sustainable Development) Act 1990 and enforced by Earth Resources Regulation (ERR), Victoria’s mineral regulatory authority.
Where possible, Currawong always elects to conduct low impact exploration activities such as mapping, soil sampling and geophysical surveys to understand the mineralisation of an area. This restricts the removal of trees or clearing of any tracks or land, protecting our native flora and fauna. We always consult with all landowners and managers prior to any exploration activity, including Crown land managers such as Parks Victoria or the Department of Environment, land, Water and Planning.
Our low impact exploration includes the following activities:
Review of historical data and mapping
Victoria has a rich history of exploration. We are able to use historical maps and data of from previous exploration activities in our licence areas to understand the nature of their geology and mineralisation before even stepping foot on the ground. If there are areas where we do not have maps available, our geologists can use handheld GPS navigators to survey any areas and produce further maps needed.
Geophysical surveys use electronic devices that measure the variation in the near surface rock formations such as gravity, magnetics or resistivity and electrical conductivity, and give us a deeper understanding of the topography of the area. These surveys can be conducted on foot, by vehicle or by aircraft and are non-invasive.
Geochemical soil and rock sampling
Once we understand the geophysical makeup of an area, our next step is to discover the chemistry of the ground below. Our geologists collect small soil samples and rock chips from an area to send to laboratories for analyses, to determine whether there is gold or other metal content present. Soil samples are generally 300-500g and taken from 15-30cm depth. Rock chips are about the same size as the palm of your hand or smaller and taken from the surface of an area. We record the locations of each sample with a handheld GPS and backfill any shallow soil coverings to their previous state.
Soil sampling technique and equipment
Exploration is Not a Licence to Mine
We do not conduct any mining or dredging as part of our exploration activities. An Exploration Licence does not allow an operator to conduct any mining activities. Mining falls under a different licencing and approval process within the ERR and approval must be granted for any mining activities to occur. The application process for a mining licence can take 10-15 years and involves extensive community consultation prior to approval.
More information: Code of Practice for Mineral Exploration, Appendix 2. www.earthresources.vic.gov.au
Once our teams have completed low-impact exploration, certain areas of interest may be identified for a drilling program, to help us understand more about the mineral content in the ground below. Any drilling we undertake requires us to submit a Work Plan to Earth Resources Regulation. This must be reviewed and approved by a variety of government departments prior to the start of any drilling. All Work Plans must include information on the following:
- heritage and environmental reviews, possible impacts, and relevant mitigations
- details on proposed works and methodology
- any landowner compensation agreements
- further administrative plans
Landowners and managers are always consulted before we access any areas for drilling, including Crown Land, with written permission and any compensation agreements required prior to the commencement of any drilling. Once we commence drilling, our crews will only operate during daytime to minimise risk to our people as well as reduce any noise or light exposure to nearby communities.
There are two main types of drilling we use in exploration: reverse circulation (RC) and diamond drilling.
RC Drilling (also knowns as percussion drilling)
This technique uses air from a compressor to drive the drilling equipment into a drill hole and helps push samples of crushed or ground rock up a pipe for sample collection. The machinery for RC drilling utilises a truck or track mounted drill rig and a compressor unit to supply air, usually mounted on second truck. A 4WD support vehicle will also accompany the trucks and is used by employees and contractors to access the drilling site. Drill depths usually range between 30m to 150m with a diameter of 10- 15cm. Samples are bagged and taken at one-metre intervals. A sub-sample of this larger sample is then extracted and sent to the laboratory for analysis.
RC drill rig with a support truck carrying a compressor in the background.
Diamond Drilling is used to extract a continuous cylindrical core of rock rather than rock chips (as in RC drilling) and the machinery used has a smaller footprint. The diamond drill rig is usually truck or track mounted, but smaller rigs may be skid-mounted for use in difficult terrain. They generally require a support truck to move supplies and at least one support light vehicle to move personnel. Diamond drilling can deliver rock sample from over 1km below surface with a similar diameter of 10-15cm but is one of the most expensive and time-consuming drilling techniques available. Water is injected into the hole to lubricate and cool the diamond-tipped drill equipment in the hole. Sometimes the water is mixed with other ingredients, such as bentonite clay, to help stabilise the drill hole when in broken and fractured rock. We ensure any drilling additives are totally biodegradable.
A track mounted drill rig capable of drilling 1000m deep.
Monitoring is conducted on all drilling sites to ensure we are achieving best practice, with regular auditing of our processes and environmental mitigations. At the completion of drilling, any samples are removed from site, drill holes are surveyed for their location and the site is then rehabilitated and monitored for environmental purposes for a further twelve months. Each drill site is photographed before, during and after the work and rehabilitation is completed so that we have a clear record of any impacts created and can assure the quality of our rehabilitation. We continue to monitor our previous drill sites to ensure that any areas do not deteriorate after we have completed rehabilitation.
More information: Code of Practice for Mineral Exploration, Appendix 2. www.earthresources.vic.gov.au
We work closely with local Country Fire Authority (CFA) brigades when planning and conducting our exploration programs to reduce any chances of a fire occurring. This is particularly important over the summer period when we ensure the following measures are taken:
- Pre-exploration season consultation with CFA to coordinate activities and update procedures from feedback of previous season.
- Maintaining regular contact with CFA so they are aware of when and where we are operating, to reduce response times, should they be needed.
- Every drill site must have a dedicated firefighting hose, nozzle, pump and 1000L of water stored.
- In accordance with Occupational Health and Safety legislation, all relevant equipment and vehicles carry a fire extinguisher. Our crews are trained to ensure they can use the equipment correctly.
- In cases of extreme weather (high temperatures or excessive wind), vehicle movement is minimised, weather forecasts are monitored, and CFA warnings factored into all planned activities.
- Exploration activities do not occur on Code Red Days. Exploration activities are modified or cancelled on days of Total Fire Ban (TFB). Drilling does not occur on TFB days.
Fire protection and preparedness is regulated by Worksafe and Earth Resources Regulation under the Occupational Health and Safety Act (2004) and Forests (Fire Protection) Regulations 2014.
More information: Code of Practice for Mineral Exploration, Part C – 14. www.earthresources.vic.gov.au
We want the communities we operate within to benefit from having us there. Currawong Resources undertakes several measures to reduce any impact from our activities on community amenity, as outlined in the Code of Conduct for Mineral Exploration. We are committed to complying with all Environmental Protection Policies outlined by the Environmental Protection Authority Victoria.
All of our activities are planned and executed with the priority of minimising any impact on community amenity. By continually assessing our activities and having open conversations with community members, we can work together to ensure we achieve best practice.
We apply the following controls to manage any impact on our local communities:
- Use of acoustic screens to reduce noise while drilling.
- Modifying operating hours to reduce noise and minimise any dust emissions.
- Careful selection of low noise machinery and reliable contractors.
- Training of all personnel to manage amenity related behaviours.
- High level of equipment maintenance.
- Use of dust controlling methods or equipment.
- Minimising vehicle movements where possible.
- Use of water to reduce dust from exposed surfaces and roads.
- Careful positioning of lighting to prevent lights outside of work area.
- Continual monitoring of noise, dust and light levels.
- Regular site inspections and audits.
We are always searching for ways to continually improve our measures and we encourage our community stakeholders to contact us with any concerns or queries in relation to community amenity. We will always respond promptly, ensuring a practical and fair solution can be found. Our community relations contact details can be found below:
Phone: 0429 822 364
More information: Code of Practice for Mineral Exploration www.earthresources.vic.gov.au
Rehabilitation is an integral part of exploration and ensures that our environment can continue to thrive after our exploration work is complete. Currawong Resources works in accordance with the guidelines by the Victorian Government and will facilitate effective rehabilitation of all disturbed areas. No wetlands, waterways or lakes will be impacted by our activities.
We will enter into rehabilitation agreements with landholders or managers to ensure sites are rehabilitated to all mutually agreed conditions. We will ensure a photographic record is taken of our sites prior to any exploration work to be used as reference in our rehabilitation processes. Any significant vegetation is identified and fenced off before any work can commence.
Some of the following rehabilitation activities are undertaken immediately after the completion of drilling:
- Backfill any drill holes with surplus drill material, i.e. soil or rock chips.
- Remove any poly pipe or cut below ground level and insert a hole plug. Backfill hole and mound with surplus material to allow for settling to the original surface level.
- Mark hole with peg/ wooden stake if required for later survey pick-up.
- Restore original land contours of drill site.
- Remove all foreign material and dispose of in an approved waste facility.
- Rake surrounding leaf litter / grass over disturbed site. Consider random placement of sticks and small logs to resemble pre-drill condition.
- Consider shallow ripping of the site and associated access tracks (with light machinery if required) as per agreement with landholder or land manager.
- If required, plant seeds (e.g. pasture, crop, native seed) to achieved desired rehabilitation outcome as per agreement with landholder or land manager.
- Take photographic record of site and access tracks immediately before and after rehabilitation (from same position as pre-drilling photos if possible).
- Completion of an Environmental Activities Report
- Audit, including photographic record, in 6 and 12 months for any subsidence and review environmental recovery.
More information: Code of Practice for Mineral Exploration Part C – 26. www.earthresources.vic.gov.au
Water can be a helpful tool in the exploration drilling process to lubricate drill holes and help supress any excess dust.
During diamond drilling, water is used to lubricate and stabilise the drill hole as well as keep the drill bit from heating too much due to friction. In some drill holes, groundwater may also be intersected in the drilling process, which can aid the diamond drilling and supplement the any water requirement.
For reverse circulation drilling, groundwater can also be encountered, just as water borers aim to do, in which case the water can aid the return of the drill cuttings to surface as it drills through rock.
If any extra water is required, it will be sourced from available water supplies located nearby. This requires permission from the local authorities, such as local catchment authorities and local governments or shires. Currawong Resources will always seek permission from the relevant authorities prior to any water use.
A diamond drilling rig on average uses approximately 2000 to 4000 litres of water per day depending upon ground conditions. Most of this added water disperses into the groundwater table through cracks and fractures in the rock. In some cases, the groundwater present is sufficient to keep the drill turning. Excess water that returns to surface is captured and recycled back down the drill hole to minimise any water consumption. Tanks are used to capture the water that is returned to surface and these act as a buffer in the water supply cycle, thus the process is fully self-contained.
Water used in the exploration drilling process is returned to its source – the groundwater table. All drilling additives are fully biodegradable and environmentally friendly to prevent any contamination of aquifers as per Currawong’s Exploration Licence requirements and the DEDJTR Code of Practice for Mineral Exploration.
More information: Code of Practice for Mineral Exploration, Part C – 10 & 11. www.earthresources.vic.gov.au