A noise management plan (NMP) must be prepared for the WEF in accordance with regulation 131E. Broadly, the function of the NMP is to demonstrate an understanding of the risks of noise-related harm associated with the operation of the WEF, and to document procedures to control those risks and rectify any noncompliance. The documented approach to WEF noise management should be practical, cost effective and proportionate to the risk of harm, and supported by verifiable evidence.

Regulation 131 E(2) requires the NMP to include procedures for:

1. the identification, assessment and control of risks of harm to human health and the environment from wind turbine noise
2. determining any alternative monitoring points and associated alternative monitoring point criteria
3. assessing compliance with: 
   • the noise limit for that facility, or
   • the applicable alternative monitoring point criterion if the assessment of the wind turbine noise is conducted at an alternative monitoring point
4. reducing wind turbine noise in the event of noncompliance with the noise limit for the facility or alternative monitoring point criterion determined for an alternative monitoring point
5. addressing any complaints about wind turbine noise received by the operator, including who will investigate the complaint and respond to the complainant.

WEF operators are required to:

• engage an environmental auditor to review the NMP 
• provide a copy of the NMP and environmental auditor’s report to the Authority (EPA) on request
• amend the NMP if requested by EPA.

Developing a noise management plan

This guideline includes elements of current good industry practice, identified through consultation with the wind energy sector, that may be useful to include when developing an NMP, as well as expanding on compliance with the regulatory provisions:

Organisational environmental strategy (regulation 131 E(2)(a))  

• Definition of organisational and other responsibilities for the measurement, assessment and management of noise emissions from the WEF.
• Requirements for reporting and recordkeeping, including document control systems, incident reporting and tracking, and records to be retained. 

Regulatory standards (regulation 131 E(2)(a))

• Summary of legislative framework requirements.
• Outline of site environmental noise objectives, including the relevant consent conditions. 

Noise sensitive areas and alternative monitoring points (regulation 131 E(2) (b), (c)(i) and (ii))

• Identification and justification of noise sensitive areas, alternative monitoring points, and applicable alternative monitoring point criteria, land use category and operational noise limits that apply at each of the locations.
• Map of noise sensitive areas in relation to the WEF, and alternative monitoring points. 

Risk assessment and controls (regulation 131 E(2)(a)) 

• Operational noise modelling, including method, input data and results.
• Risk analysis and assessment, including identifying major noise sources and evaluating and assessing risks of harm to human health and the environment from wind turbine noise.
• Evaluation of likelihood and consequence of risks, development of a risk matrix and risk management approach.
• Consideration of control measures to address noise-related hazards and determination of residual risks.

EPA Publication 1695 Assessing and Controlling Risk (publication 1695) provides a framework for risk assessment.

Operational performance (regulation 131 E(2)(c))

• Details of noise measurement procedures, including equipment requirements, timing and duration.
• Wind-speed measurement locations and analysis approach for wind speed data.
• Noise level and wind-speed measurement data analysis approach, including for subjective and objective evaluation of Special Audible Characteristics (SACs), and procedures for data exclusion, where necessary.
• Approach for attended subjective observations.
• Summary of results of operational noise monitoring and compliance assessment, including at alternative monitoring points.
• Summary of baseline meteorological conditions (consistent with the compliance documentation required under section 8.3 of the 2010 Standard including atmospheric conditions (wind speed and direction, rainfall)). 

Site inspection and maintenance (regulation 131 E(2)(a)) 

• Details of the maintenance plan and routine maintenance activities.
• Requirements of ongoing condition monitoring and inspections that may influence noise emissions.
• Procedures for unexpected (non-routine) maintenance activities.
• Procedures for scheduled inspections and monitoring.  

Noise complaint management procedures (regulation 131 E(2)(e))

Reflecting good practices set out in AS/NZS 10002:2014 Guidelines for complaint management in organizations, complaint management procedures should include:

• details of how the community can lodge a complaint, including contact details
• a complaint register to record information for each complaint received, which may include:
  • the name and address of the person making the complaint
  • procedures on how complainants’ details will be maintained, including any relevant privacy policy
  • a receipt number for each complaint, which is to be communicated to the person making the complaint
  • any applicable property reference number (for example when connected to a background sound measurement location)
  • the time, prevailing conditions and a description of the concerns reported
• investigation and response procedures, which may include:
  • a proforma noise investigation report
  • procedures for the analysis of complaint data against environmental conditions and WEF operational data
  • procedures for taking measurements to assess wind turbine noise levels in response to complaints 
  • procedures for communication, consultation, and engagement with any relevant stakeholders.

WEF operators should also consider a proactive program for contacting community in nearby noise sensitive areas to determine if there are unreported complaints.  

Noise remediation procedures (regulation 131 E(2)(d))

• For situations where noncompliance has been detected (either as a result of investigating a complaint or through other routine monitoring procedures) the NMP must set out noise remediation procedures to address noncompliance and to reduce noise emissions. 

Training (regulation 131 E(2)(a))

• Develop and implement a training program for employees engaged in the operation of the WEF, including the provision of information, instruction, supervision and training, particularly about their duties under the EP Act.

Review (regulation 131 E(2)(a)) 

• Program for review, including the development of the annual statement, five-yearly wind turbine noise monitoring and NMP review cycle. 

Alternative monitoring points

Alternative monitoring points, as determined in accordance with r.131BB, may be adopted in NMPs for complaint response purposes or during five-yearly monitoring assessments monitoring activities under r.131G.  

An alternative monitoring point may be used if a monitoring point for the WEF is not readily accessible, or where an alternative monitoring point is closer to the wind turbines being assessed and has less extraneous noise than the monitoring point at the noise sensitive area.

This approach is commonly adopted in environmental noise assessment of industrial facilities, particularly where it is impracticable or impossible to undertake compliance measurements at a noise sensitive receiver itself.

When alternative monitoring points are used, a well-established theoretical or empirical relationship between the noise levels at the alternative monitoring point and the noise sensitive area should be used and appropriately justified in the NMP or five-yearly wind turbine noise monitoring report. For example, concurrent noise level monitoring at the monitoring points determined in accordance with the relevant noise standard, and any alternative monitoring points, or the use of computer noise modelling, can help determine alternative monitoring point criteria.

Alternative monitoring point criteria

When an alternative monitoring point is used, an alternative monitoring point criterion must be set for that alternative monitoring point.

An alternative monitoring point criterion is the maximum noise level that cannot be exceeded at the alternative monitoring point, expressed in dB(A). This noise level must be determined by a suitably qualified and experienced acoustician so that an assessment of wind turbine noise against the alternative monitoring point criterion accurately represents an assessment of wind turbine noise against the noise limit at the monitoring point.

This means that the compliance of wind turbine noise with an alternative monitoring point criterion at the alternative monitoring point should be representative of compliance with the noise limit at the monitoring point. The acoustician must explain how the alternative monitoring point criterion has been determined and why the alternative monitoring point criterion represents the noise limit, having regard to the environmental or other relevant factors that differ, between the monitoring point and the alternative monitoring point.

These may include, but are not limited to:

• the difference in distance relevant to the wind turbine(s)
• the difference in the level of extraneous noise
• the difference in background noise levels and why there is an increase in background noise (if that is the case)
• the difference in topography
• the difference in acoustic attenuation caused by structures and vegetation
• the difference in exposure to the wind turbines
• the operational status of wind turbines at the time the alternative monitoring point criterion was determined

More than one alternative monitoring criterion may be required if:

• there is more than one alternative monitoring point, or
• multiple noise limits apply to a noise sensitive area (for example, a high amenity noise limit at night).

Auditor review/verification requirements (regulation 131E (3) and (4))

The NMP must be reviewed by an EPA-appointed environmental auditor. 

Current EPA auditor guidelines are available in EPA publication 1692 Wind energy facility noise auditor guidelines. 

This review should present concise conclusions about the extent to which the NMP: 

• demonstrates an understanding of the risks of noise-related harm associated with the operation of the WEF
• includes procedures:
  • that would be effective in controlling those risks and ensuring compliance with the noise limits
  • for noise remediation if noncompliance is identified
  • for complaint investigation and resolution
• justifies the suitability of any alternative monitoring points and alternative monitoring point criteria.