Saturday 13 September 2014

Aviation noise from Badgerys Creek in Western Sydney

Previously I wrote a post showing the potential flight paths of Badgerys Creek airport; today's post is to try to get an understanding of what that means in terms of noise for local residents. What noise will you experience if you live under one of these flight paths?

Unfortunately if you read the newspaper and look at their maps you will probably walk away with a false impression of whether you will be affected by noise. This is because most articles show the ANEF map; this has already be proven to be misleading as found by a senate committee (see http://www.infrastructure.gov.au/aviation/environmental/transparent_noise/expanding/index.aspx). People want to know how noise will be like on a bad day or night rather than just an average. The real issue is that the purpose of the ANEF map was never meant to show the community the possible noise impact to them but rather how noise will impact city planning and zoning. The community however has a much stricter criteria; they aren't interested if they can get away with developing a house - they rather know that if they lived there what the noise would be like for them.

Firstly just so you may have an understanding of the information I've attached further down in this post I've grabbed the below examples of sound and their "loudness" in decibels (db) from Sydney Airport's noise management plan. Note that the decibel scale is not linear - an increase in 10db represents a doubling of the sound volume.

Threshold of pain 140db+
Pneumatic drill (unsilenced at 7m distance) 95db
Heavy diesel lorry (40km/h at 7m distance) 83db
Modern twin-engine jet (taking off at 152m distance) 81db
B737-800 jet: arriving at Sydney Airport (flying over Leichhardt) 75.4db
B737-800 jet: departing from Sydney Airport (flying over Croydon) 2 70.9db
Passenger car (60km/h at 7m distance) 70db
Office environment 60db
Ordinary conversation 50db
Library reading room 40db
Quiet bedroom 35db
Threshold of hearing 0db

Nowdays airports in their noise management plans show three maps in their plans. These include:

  • The ANEF map
  • The N70 map which shows areas that are likely to be affected by aircraft noise above 70db and how often in a 24 hour period.
  • The N60 map which shows areas that are likely to be affected by aircraft noise above 60db. This is normally provided for nighttime exposure only since this is the sound level that when inside will cause you to wake up from sleep.
The rationale for choosing 70db as the sound level for these maps comes from the fact that any sound above 60db will disrupt indoor conversation and general household activities. Assuming your inside your house a 70db sound outdoors will be reduced to 60db by the time it makes it inside. In other words it's really 60db of sound that will be disruptive; its just lucky your always inside right?

I've put the N70 maps below of Badgerys Creek and Sydney Airport for you to compare.

N70 Map for Badgerys Creek Option A Operation 1 - Takeoffs to North East (Source: Supplement to Draft EIS Second Sydney Airport Proposal Volume 3 Supplement Part E Chpt 8)

N70 Map for Badgerys Creek Option A Operation 2 - Takeoffs to South West (Source: Supplement to Draft EIS Second Sydney Airport Proposal Volume 3 Supplement Part E Chpt 8)

N70 Map for Badgerys Creek Option C Operation 1 - Takeoffs to North (Source: Supplement to Draft EIS Second Sydney Airport Proposal Volume 3 Supplement Part E Chpt 8)

N70 Map for Badgerys Creek Option C Operation 2  - Takeoffs to South (Source: Supplement to Draft EIS Second Sydney Airport Proposal Volume 3 Supplement Part E Chpt 8)

N70 map for Sydney Airport (Source: Sydney Airport Master Plan 2033)


N60 maps are also shown as well by established airports (see Bankstown Airport Noise Plan and Sydney airport night time curfew maps) which has more of a bearing on outdoor activities. Unfortunately for us Western Sydney locals we only have a predicted night time N60 map that in my opinion isn't much use. This is because it has been compiled with the assumption that there is a lot less aircraft traffic during the night and therefore less noise to measure. I don't believe this assumption to be correct since one of the main appeals of this airport is that it probably won't have a curfew and Mascot will continue to do so. It could just very well be night time passengers and freight are the main markets for this airport who would otherwise have to wait for a slot outside curfew hours at Sydney Airport - at this stage we don't know.

To illustrate my point even with a curfew the N60 maps over the sea provided by Sydney Airport look like below - there are still 20+ events per night 12.5km's away near Bundeena even with curfew restrictions. Contrasting this the Badgerys EIS only tells you that you will get more than 5 events each night at this distance. Sydney Airport also has the advantage of being able to send planes out to sea of course:


N60 Map for Badgerys Creek Option A (Source: Supplement to Draft EIS Second Sydney Airport Proposal Volume 3 Supplement Part E Chpt 8)

N60 Map for Badgerys Creek Option C (Source: Supplement to Draft EIS Second Sydney Airport Proposal Volume 3 Supplement Part E Chpt 8)

N60 Night Time Curfew Map for Sydney Airport (Source: Sydney Airport Master Plan 2033)

Despite my previous doubts on the N60 map shown above for both Option A and Option C runway configurations it still shows that unfortunately there will be many sleepless nights for the people in the areas nearby (e.g Leppington, Mulgoa Rise and more). It has to be noted that these N60 maps were made in 1997; a lot of housing development has happened since then. There is the reason why in 2009 the Aviation White Paper released by the Labor Government ruled out the use of Badgerys Creek - "Badgerys Creek is no longer an option. It has been overtaken by years of urban growth in the area and is inconsistent with future NSW spatial planning and land use development for the south-west region of Sydney."

What I would like to see in any updated EIS (Environmental Impact Statement) is an N60 worst day (in the daytime) map for each runway configuration that is proposed similar to the one Sydney Airport prepared for its night time hours. That's what likely to be disruptive to your day to day activities when your for example enjoying a family picnic or playing an outdoor sport. This should then be shown to the community so they fully understand what noise they will experience and where it will be located.

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