Meeting noise limits while increasing production

Mines close to dwellings are usually subject to strict noise limits. Managing noise from the mine is complicated by dynamic operations, changing weather conditions and the confounding effect of non-mining noise sources. 

The most common response to these challenges is conservative operational planning whereby mine operations are restricted. The method miners use to address the ambiguity and uncertainty noise creates is to operate with a sufficient safety margin – resulting in lost production opportunity. 

To eliminate the need for a safety margin, miners need to manage noise in sync with changing conditions. Due to the speed of change and the many interactions that need to be considered, noise management without a safety margin must be done by operations personnel directly. To enable this, miners need a tool that is intuitive to use and fast enough to keep up with the dynamic environment.  

Using a new application of technology, miners can now unshackle production at noise-constrained operations.

Existing approaches

The most common approach to managing mine noise involves recording noise levels for relatively short periods. However, it may not be practical to determine whether the mine is in compliance because the monitoring periods are not long enough to capture noise over a representative range of conditions.

Permanent monitoring systems can be used to alert miners when noise limits are exceeded and to capture supporting data. Such systems enable miners to respond more effectively when complaints are received. However, the system alone cannot accurately determine which mine noise sources contribute to exceedances, obscuring potential solutions. 

Some Australian mines also use noise modelling to predict whether planned activities will meet noise limits and adjust the plan until compliance is attained. This allows production losses to be contained because noise management becomes less reactive. However, it is limited by the slow execution of the model and the need for modelling to be done by trained personnel. As a result, miners still need a safety margin because they can’t manage noise in concert with operations.

Unshackling production

To manage noise effectively, miners need a solution that gives them the information they need to make decisions in the context of current operations and weather conditions. 

SVT offers a proprietary solution, called MaestroMine, that helps miners solve operational noise problems. The user interface enables miners to identify and solve potential noise problems by manipulating equipment types, quantities and locations.  

The predictive noise model calculates the impact of changes in operations or weather within seconds, enabling miners to stay ahead of dynamic conditions.  

The model is continuously validated against data from permanent noise monitoring stations, providing miners with the confidence to act on the output.

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A quality noise survey reduces cost for operators by recommending practical, targeted controls for dominant sources of hazardous exposure. 

Many surveys fail to do this, committing facility operators to wasteful expenditure on ineffective noise controls. 

Wasteful spending includes noise controls on equipment not in a work area and therefore not exposing people to hazards. Controls that impact on the operation of equipment or introduce safety risks are also impractical. We have also seen controls recommended in noise reports that simply do not produce any attenuation in noise. 

Poorly conceived controls can arise when noise officers aren’t able to attribute the levels they measure with the actual sources of exposure.

A noise survey is a regulatory requirement and is a key step in reducing exposure for workers. It identifies sources of hazardous noise by measuring and ranking noisy equipment that contribute to exposure.

Production facilities often have significant numbers of employees whose exposure exceeds the allowed limit, 85 dB(A) averaged over an eight-hour shift. When a noise survey finds excessive exposure, employers must commit to reducing it through a noise control plan.

A targeted noise survey facilitates the efficient preparation of a noise control plan, avoiding waste by:

• Using the noise officer’s time effectively: Hazardous exposure is often caused by a small portion of the equipment on a site. Focusing on equipment that exposes workers to hazardous noise minimises the time required to collect and process data. This approach reduces cost while ensuring that the important data are captured.
• Recommending effective controls: Effective noise controls reduce exposure without compromising safety or operations. The best return on investment, measured as a ratio of risk reduction to cost of control, can be achieved by treating the noise sources that contribute most to exposure.

An effective noise control plan also aligns with the organisation’s goals and strategies, business drivers and values. Willingness to accept trade-offs between risk and benefit or operational and capital spending vary between companies and industries. These factors determine the best way to manage noise for each company.

Managers armed with a targeted noise survey can commit to controls that are practical to implement at their facility and are effective in reducing exposure.

Jim McLoughlin is the head of the Noise business unit at SVT Engineering Consultants.

The Queensland Department of Natural Resources and Mining has released a new guidance note on noise management that aims to provide greater clarity on what mine operators must do to comply with safety acts.

QGN 22: “Guidance Note for Management of Noise in Mines” sets out a risk management framework with the goal of reducing noise exposure to as low as reasonably achievable. 

The document, published at the end of August 2014, outlines how a risk based approach can be employed by mine operators in Queensland to manage occupational noise.

The guidance note, the first of its kind in Queensland, was developed and agreed jointly by government, industry and trade union representatives.

The note builds on existing regulations, explaining how to approach, determine, analyse and monitor noise exposure risk. It emphasises the need to manage risk using a noise management plan as part of the mine’s health and safety management system.  

“For a risk to a person to be at an acceptable level, operations at a mine must be carried out so that the level of risk from the operation is not only within acceptable limits but also as low as reasonably achievable,” the document says.

SVT is experienced in helping production facilities work towards compliance and to demonstrate to regulators that the noise exposure of their employees is as low as reasonably achievable.

Richard Pamley is a principal noise consultant with SVT Engineering Consultants.

Operations in marine settings can be impeded by unnecessarily conservative noise boundaries that are defined by assumptions instead of actual data. 

Noisy underwater activities such as seismic surveys and piling can damage the hearing of marine fauna, which they rely heavily upon. Dolphins, for example, use echo location to navigate and find food.

The current way of managing noise exposure for marine fauna works on a series of hard boundaries. For example when fauna enter a predefined exclusion zone around operations, work must cease and can’t resume until they have left the area. This method of limiting noise exposure is not necessarily effective in protecting fauna as actual exposures are unknown. It is also not practical for operators performing seismic surveys or piling to comply with this approach because of the prohibitive cost of suspending work — a seismic survey cost as much as AU$700,000 per day.

The best way to maximise the operating envelope of noise constrained activities without compromising fauna hearing is to use an adaptive approach. 

The benefits are that fauna hearing is not compromised and the operational noise envelopes companies work within are maximised. 

SVT uses a real-time adaptive noise management tool that combines marine fauna observer data, operations data, measured noise data and real time modelling to determine actual marine fauna exposures. 

The tool provides operators with an evidence based system that enables them to make the right decisions for their business. 

Contact us to find out more about SVT’s adaptive underwater noise management tool.

Demonstrating regulatory compliance for noise exposure in offshore environments is difficult when there is no process or documented evidence of due diligence. 

With noise it is not always clear how you comply: regulations can be vague and the burden of proof for compliance is on the proponent.

Using a clear process to decide on noise controls makes achieving compliance simple.

The ability to demonstrate that noise control has been implemented at an ALARP (As Low As Reasonably Practicable) position gives regulators surety that operators have gone through a process that produces the best and most balanced noise control scenario.

The legal definition of ALARP in Australia states that a calculation must be made to show that the noise controls chosen are effective and that a disproportionate amount of effort would be required to produce additional benefit. 

ALARP decisions get reviewed by regulators, such as NOPSEMA in the case of offshore oil and gas facilities, and must be rigorously defined.

SVT’s ALARP tool Podium makes the act of achieving compliance simple, by using a tried and tested process developed with multinational resources companies. The tool has a 100 percent pass rate for all regulator audits.

Podium brings noise control expertise into the room to guide the process while combining corporate values and relevant stakeholders (safety, maintenance, operators), allowing them to have input to ensure the controls are effective and practical.

In 2014, SVT is bringing Podium to market through the internet in a format that can be used by clients in remote locations as well as in the meeting room.

By using Podium, your compliance issues around noise emissions will become simpler to deal with and you can focus on solving other issues.

Try our ALARP demonstrator to see how you come to an ALARP decision based on real world inputs.