How WestConnex Noise and Vibration will impact on Alexandria

noise_table_111_treatmentContributed by one of our co-ord group members.

On my reading of the EIS chapters, there are impacts on Alexandria both on the noise and vibration front, but the main impact on us is noise. The EIS generally dismisses vibration as an issue that won’t cause us problems. ( EG See, Vol 2D, App J Page 149 5.5.2 ).

There are a couple of points worth making and they fall into Broad and Specific, as follows:

Broad impacts:

  • the plan is to create the tunnels by blasting rather than by mechanical excavation. The justification appears to be speed and shorter burst impacts on any given area. There are many assurances about control and precedent, but you have to think it is inherently more risky and uncontrolled.
  • the Interchange and surrounding roads program is a 2.75 year construction project.
  • Hours of operation: Normal is 7am-6pm; evening is 6pm-10pm; night is 10pm-7am. However, pretty much anything they like can be done during the evening and night shifts if they deem it safe and/or appropriate to do so! And noise mitigation measures would be the same, whether day or night. ( see Vol 1B, Ch 12, Page 62)
  • each designated Noise Catchment Area ( Alexandria is NCA1) only has one data logger. In our case it was at the edge of Sydney Park between Mitchell and Euston.
  • re Project Impact, everywhere where the project impact is more than 2db to noise levels, those areas are consistently characterised as ‘Highly Urban’, allowing a justifiable higher level of ambient noise. The boundaries between ‘Highly Urban’ and other are very inconsistent and not generally good for us. Example at Vol2D, Appendix J, Appendix F – St Peters Interchange Study Area

Specific impacts:

  • while the ventilation stacks at Kingsgrove and Arncliffe are to be approx 30 m above ground, the St Peters ventilation stacks will be about 20m above ground ‘in line with the Australian Government’s Civil Aviation Safety Authority requirements’. ( Vol2D, Appendix J, pg15, Table 3)
  • Traffic figures: Euston Road goes from 11.4k vehicles in 2021 if WC is not built, to 71k vehicles if it is built. (Vol 2D, App J, Appendix E, page 1)
  • Noise levels 2021 and 2031, if the project is built, all along Sydney Park Road and both sides of Euston Road all properties will register the highest noise level band, i.e. >65db at both day and night ( Vol2D, App J, Appendix L – Operational noise results).
  • 4 properties in Euston and Lawrence Streets are identified as eligible for sound mitigation. Many more in St Peters and elsewhere.( Vol2D, App J, Appendix M – Operational noise results – road traffic tables). The curious thing is that where noise levels are identified as ‘exceeding Cumulative Limit’, in some cases the property in question is eligible for assistance and in others they are not.
  • There is no measurement of the impact of construction traffic coming from the north to the St Peter’s Interchange site. So, no modelling of the impact on Euston or Mitchell et al. ( Vol 1B, Ch 12 Table 12-42 and following)
  • out of hours construction work for road tie-in works is predicted to cause excessive noise for 974 receivers in our broader area and sleep disturbance levels for 425 receivers. Kerbing and drainage is predicted to cause excessive noise for 1262 receivers in our broader area and sleep disturbance for 804. The figures for Alexandria specifically are 163/67 and 180/151 respectively. ( Vol 1B, Ch 12, Page 69 Table 12-34
  • there is a lot of excessive noise to be endured by the residents of St Peters in particular, but also Sydney Park and Alexandria. E.G. In St Peters, rock hammering will result in an excess of 50db above benchmark, 248 receivers will exceed the norm and of those 100 will be highly noise affected. Even earthworks with no rock hammering will result in an excess over norm of 40db, 161 receivers will exceed the norm and of those 86 will be highly noise affected. ( Vol 1B, Ch 12, Page 54, Table 12-22)
  • meanwhile, everyone will suffer excess noise from kerning and drainage. In Alexandria, the excess above norm will be 43db, 45 receivers will be affected and 13 will be highly noise affected ( Vol 1B, Ch12, Page 55, Table 12-22)

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