MANAGEMENT OF NOISE

Given the location of the proposal in a rural setting, with several nearby neighbours, there exists the potential for noise from mining to affect amenity over a long distance over the flats. The closest dwelling is within 500 m of the proposal’s disturbance area, although the occupier is the owner of the private land on which a portion of the HVN deposit is located. A further five dwellings are located within 2 km of the disturbance boundary  (Sensitive premises (map)). 

Potential Impacts

Highest noise generating activities from mining are usually associated with heavy machinery movements, such as scrapers, bulldozers or front end loaders. Night time activities at the minesites are usually significantly less noise-intensive than daylight activities. For example, heavy earthmoving equipment such as scrapers and excavators, are very rarely used outside daylight hours. Noise levels can be significantly influenced by weather conditions such as wind speed and direction and temperature inversions 

Additional studies and consultation are underway to produce a definitive assessment of noise impacts from the project.  For transport noise, i.e. that associated with heavy haulage from the site, the main route is already subject to transport noise as trucks move from the Gwindinup plant sites to the main transport corridor: the South West Highway.  This route has been previously assessed for likely transport noise impacts and recommendations on managing transport speed and movements have been incorporated into the environmental management plan for the Gwindinup site.  The Happy Valley assessment area for traffic noise will be in two parts: those residences alongside the haulage route linking the proposed HVN plant site to the existing haulage network and have not had significant or regular exposure to heavy road transport in the past; and those residences that are alongside the existing haulage network and would have been exposed to heavy transport noise for some time. 

Management Strategies

The management of noise impacts in the past by the proponent has proven effective on many occasions. Many of these strategies will be implemented at Happy Valley, with the scope for implementation of additional contingency plans if noise levels require additional control.

Because of the potential for noise impacts from mining activities each of the proponents' sites including the proposed happy Valley project, will have its own noise management plan.  Such plans are frequently audited and reviewed.The noise management plan will be outlined in the ERMP, and will include measures such as:

• Regular sound power checks on key plant and equipment, in accordance with AS/NZS 2012.1:1990.
• The installation of noise reduction measures on mobile equipment.
• Construction of bund walls and other noise barriers/screens.
• Regular noise monitoring at boundaries and at noise sensitive premises (as part of consultation and operations).
• A transport plan, describing optimal truck speeds, the maximum number of journeys and the time of day for truck movements that will best meet the draft EPA guidelines.
• Monitoring traffic noise and routine consultation with affected residences.
• Complaint response procedures.
• Reporting and revision requirements.

MANAGEMENT OF DUST

Mining and other major land development activities are often associated with the emission of windborne particulates, or dust. While usually quickly dispersed, dust impacts tend to be cumulative in that dust may build up over time on surfaces in or around residences and other sensitive areas (including vegetation) and can result in nuisance or health impacts.

Potential Impacts

There is the potential for vegetation to be covered by dust emitted from the mining operations. This particulate layer may hinder plant functions by reducing light penetration or the exchange of gases by the leaves (ICMM 2006). The emission of smoke from the burning of woody debris may also impact on the health or amenity of nearby residences.

The location of residences within 2 km of the HVN and HVS deposits are shown in Sensitive premises (map). While the 2 km assessment area is based on an arbitrary number, it is considered to be very conservative as previous mining experience indicates that significant nuisance impacts are rarely experienced beyond 500 m from operations. Experience shows that the easterly wind which prevails in the drier summer and autumn months can be strong and gusty and therefore increases the risk of dust generation. This increases the potential for dust generation at residences to the west and north-west of the HVN deposit. Further studies are underway as part of the development of the ERMP to fully determine the potential dust impacts on nearby residences.

Management Strategies

The effectiveness of the management of dust and smoke at existing and previous minesites has been proven on many occasions despite the close proximity of some previous operations to dwellings and townsites. Many previous management strategies will be applied at Happy Valley, along with new strategies being applied at the existing Gwindinup minesite. This will enable management actions and contingencies based on Gwindinup experiences to be incorporated into the Happy Valley Environmental Management and Monitoring Program.

Dust and smoke are managed as procedures and work instructions through the EMS, which will be presented in the ERMP for review.  Dust and smoke management measures include:

1. Minimising and stabilising cleared areas and stockpiles.
2. Minimising burning of clearing residues.
3. Regular application of dust suppressants, including water and specialist suppressants, on roads and other high risk areas.
4. Stabilising high-traffic areas, such as main access points.
5. Maintaining buffers, where available.
6. Consultation and complaint resolution procedures.