Environmental implications guidelines
These guidelines will assist you to complete the Environmental Implications Form (Form 080). The information is provided as a guide only and is by no means exhaustive. Further information on environmental issues is available from the Department of the Environment, Water, Heritage and the Arts or by contacting the OAR.
1. Aircraft noise
Is the proposed change likely to change the level of aircraft noise exposure at ground level, or the pattern of noise exposure, particularly over built-up areas?
If yes, will this change be caused by a change in aircraft type, the number of aircraft, aircraft configuration, operating heights, flight tracks or other factors? (State which.)
Describe the nature of the change(s). Quantify the change(s) and provide maps where relevant.
Considerations
The level of sound is an important indicator of environmental quality. Noise has been defined as unwanted sound in the environment. It is important to note that 'noise' is considered a significant environmental effect in the EPBC Act Policy Statement 1.2 – Significant Impact Guidelines.
Locations distant from an operating aircraft are exposed to a level of sound that is a function of the level of sound emitted by the aircraft, the distance of the receiving location from the aircraft, the characteristics of the sound, ambient atmospheric conditions and any physical barriers between the source of the sound and the receiver.
Aircraft Noise
The principal sources of noise from an aircraft are engine noise, propeller noise, rotor noise in the case of helicopters, airframe noise and burner noise from balloons.
Aircraft operations that could cause a noise disturbance are arrivals, departures, changed flight tracks, frequent low-level operations over residential areas, unusual operations, prolonged hovering by helicopters, repeated operations such as training flights, low level operations over national parks, nature reserves and passive recreation areas and the activities of defence aircraft.
The noise generated by a jet or propeller-driven aircraft operating at normal cruising levels (usually about 35,000 ft for a commercial jet airliner), does not normally cause concern at the closest point on the ground to the aircraft as the distance between the aircraft and the receiver is normally sufficient for the noise of the aircraft to be low or even non-existent when it reaches the receiving site. The main exceptions would be helicopters and balloons, which normally fly at relatively low altitudes, and those types of military aircraft that are inherently noisy. Aircraft flying at speeds greater than Mach 1 (the speed of sound) would cause an unacceptable disturbance or impact because of the characteristics of the sonic boom.
Hot Air Balloons
Hot air balloons, although usually associated with quiet mornings, are actually inherently noisy. In fact, one study states that 'the hot air balloon burner generates a level of noise between that of a freight train (88 decibels) and a circular saw (107 decibels).' Remember, a 70 decibel sound level will sound twice as loud as a 60 decibel sound level.
Low Level Flying
Aircraft flying at levels below their normal cruising altitudes may cause levels of noise exposure greater than generally acceptable limits. They may also cause impacts within communities regardless of whether acceptable levels are exceeded or not because of either an awareness of a change having occurred or the heightened sensitivities of some people.
Noise Impacts on Wildlife
Any proposal for airspace change that may cause a 'noise' effect on wildlife must be further examined in order to determine the likelihood of long-term effects which may be detrimental to the survival of the wildlife.
Noise in the National Parks System and Heritage Listed Areas
Noise within the National Parks system often interferes with the very reason visitors go to the National Park – for peace and quiet. Aircraft noise tends to interfere with the 'natural quiet' that visitors seek within a National Park. Another consideration for aircraft overflying National Parks is the reduction in enjoyment and appreciation of cultural and historical resources within the Parks and the perceived reduction of the sounds of nature.
Any airspace change proposal which may interfere with the natural quiet of a National Park and/or Heritage listed area must be further investigated in order to determine any long-term effects which may reduce the visitor's enjoyment.
Conclusion
Any change to the pattern or level of aircraft noise at ground level always has the potential to attract community criticism, media interest and political comment. Thus, any changes pose a potential environmental business risk.
2. Vibration
Is the proposed change likely to vary the level or pattern of aircraft-induced vibration at a sensitive receiver site or over a residential area?
If yes, describe the nature of the change(s). Quantify the change(s) and provide maps where relevant.
Considerations
Harmonic vibrations can be caused in buildings and in items within buildings by the low-frequency component of aircraft noise. Vibrations caused by aircraft noise can create vibrations in archaeological resources, structures and museum objects. Although rarely harmful or destructive, some people and animals are sensitive to vibrations caused by aircraft and find them a cause of concern.
For the purpose of vibration and its effects on structures, the noise from aircraft has been divided into three distinct types; sonic booms, fixed-wing noise and helicopter noise.
Supersonic aircraft flight and overflights by very large aircraft or helicopters can produce vibration levels that may cause structural vibrations.
Any proposal for airspace change that may lead to a change in the pattern or intensity of vibrations in areas under a flight path (especially sensitive areas such as archaeological sites, historical sites and cultural sites) must be further investigated in order to avoid long-term damage.
3. Privacy
Will the proposed change allow low-level operations in the vicinity of residential facilities, recreational areas or other sensitive sites that might be perceived as invading the privacy of people in those areas?
If yes, describe the nature of the change(s). Quantify the change(s) and provide maps where relevant.
Considerations
Helicopter, balloon and powered parachute operations and, to a lesser extent, light aircraft and ultra-light operations, have significant potential to invade the privacy of individuals, groups and communities by allowing the occupants of the aircraft to observe properties and activities at close range and from positions of visual advantage. Numerous instances of the perceived invasion of privacy by aircraft have been cited in correspondence to aviation administrators and must therefore be considered in assessing any ACP.
Any ACP that would allow a low-level flying operation in the vicinity of residential facilities, recreational areas and other sensitive sites, especially by aircraft that can operate at low speeds, must be further investigated in order to avoid privacy issues.
An exception to privacy issues would be the operation of fixed-wing aircraft on standard approach and departure paths to registered airports and aerodromes.
4. Interactions with birds and animals
Is the proposed change likely to result in interactions (including exposure to noise and vibration) with bird or animal species in their natural states?
If yes, describe the nature of the interactions (i.e. low flying operations).
Considerations
Interactions with birds and animals may be direct, as is the case with bird strike, or indirect, through the effect of noise, vibration or presence of an aircraft.
Impacts on bird populations may occur, for example, when aircraft operations interfere with their habitats, breeding cycles, migratory patterns or feeding patterns. These impacts are most likely to occur in the vicinity of an active airport or where low-level operations disturb nesting or roosting birds. Sightseeing and training operations in the vicinity of nature reserves and in coastal areas are of concern to conservation authorities.
There is also concern that increased noise levels could interfere with echolocation of bats and marine mammals, impacting their ability to navigate, communicate, breed and locate food.
Although it is often difficult to confirm the nature and extent of animal response to aircraft noise, areas of native bird or animal concentration and, in particular, habitats of known threatened species should, as far as practicable, be protected.
If an airspace change is likely to have an effect on native or domestic bird or animal populations, further environmental investigations are recommended to avoid long-term population impacts, particularly on rare, threatened or endangered animals.
5. Emissions from low-level operations
Is the change likely to cause a change to fuel burn or the nature, volume or composition of combustion products, or cause changes in the atmosphere?
If yes, describe the change(s) in emissions, identify the combustion products involved and describe possible atmospheric changes.
Considerations
Any proposal for airspace change that reduces the amount of fuel burn by reducing the time spent in the air would reduce the amount of emissions emitted by aircraft and would therefore have to be seen as advantageous.
The environmental significance of emissions from low-level operations will depend on the quantitative, qualitative and, in particular, the cumulative changes in fuel consumption.
6. Emissions from high-level operations
Is the change likely to cause a change to fuel burn or the nature, volume or composition of combustion products, or cause changes in the atmosphere?
If yes, describe the change(s) in emissions, identify the combustion products involved and describe possible atmospheric changes.
Considerations
Once an aircraft has reached an altitude of over 1,000 ft, its contribution to air pollution at ground level is negligible. However, high-level aircraft operations produce nitrogen oxides (NOx), primarily from the oxidation of air at high temperatures within internal combustion and gas turbine engines.
NOx are produced by the reaction of atmospheric nitrogen and oxygen within the high temperatures of aircraft engines. At high altitudes, NOx produced by jet aircraft reacts with atmospheric oxygen to increase the concentration of ozone; which the Intergovernmental Panel on Climate Change (IPCC) claims to be a greater contributor of aviation greenhouse effect than CO2.
The impact of aircraft emissions on the atmosphere is a function of the volume and nature of the emissions and the accumulation of emissions over time. Expert advice should be engaged if an ACP is likely to cause a significant change in fuel burn, increase cumulative emissions or change the composition of emissions.
7. Matters of national environmental significance
To the best of your knowledge, are there any matters of National Environmental Significance that could be affected by this airspace change? Matters of National Environmental Significance include, but are not limited to: threatened and migratory species, Ramsar wetlands, the marine environment, World Heritage properties, National Heritage places and nuclear actions. If unsure about whether matters of National Environmental Significance are located within the area affected by the change, refer to the Protected Matters search tool on the Department of the Environment, Water, Heritage and the Arts website. (State which matters are affected and how they are affected.)
Considerations
The matters of National Environmental Significance that must be considered in all ACPs are listed in the EPBC Act as:
- listed threatened species and communities,
- migratory species,
- declared Ramsar wetlands,
- Commonwealth marine areas,
- World Heritage properties,
- National Heritage places, and
- nuclear actions.
Some questions that should be considered with regard to the matters of national environmental significance are:
- Are there any matters of national environmental significance located in the area affected by the ACP?
- Considering the ACP at its broadest scope, is there potential for impacts on matters of national environmental significance?
- Are there any proposed measures to avoid or reduce impacts on matters of national environmental significance?
- Are any impacts of the ACP on matters of national environmental significance likely to be significant impacts?
If unsure about whether matters of National Environmental Significance are located within the area affected by the ACP, refer to the Protected Matters search tool on the Department of the Environment, Water, Heritage and the Arts website.