C3 10 Flower Street SSCNVMP

C3

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10 Flower Street SSCNVMP

C3.1 Introduction

This Site Specific Construction Noise and Vibration Management Plan (SSCNVMP) is for the residential building located at 10 Flower Street. It is reproduced from the Mt Eden Enabling Works CNV DWP, where construction was predicted to exceed the standards in CRL designation conditions 31 and 32. A SSCNVMP is not required for the Mt Eden Station Main Works. It is included for information to ensure consistency across project stages. This SSCNVMP has been prepared in accordance with CRL designation conditions 37 and 38 and is Appendix C3 of the CRL Mt Eden Main Works Construction Noise and Vibration Delivery Work Plan (CNV DWP). It is a supplementary document that builds on the CNV DWP, and therefore directly references relevant sections of the CNV DWP to avoid repetition. The objective of this SSCNVMP is to detail the best practicable option(s) (BPO) to avoid, remedy or mitigate the identified adverse effects from noise and/or vibration exceedances at 10 Flower Street.

This SSCNVMP has been prepared for the Link Alliance and forms part of the Construction Environmental Management Plan (CEMP) for the Mt Eden Station Main Works.

C3.2 Engagement

Mt Eden Enabling Works (for information)

Link Alliance representatives Sonya Leahy, Thibaut L'Hopital, Aidan Kirkby-McLeod, Duncan Whyte and Craig Fitzgerald met with building representative Wayne Brown (building manger) on 5 September 2019. The matters discussed included:

An overview of the project General programme, demolition, piling, rock breaking/blasting and tunnelling activities

Overview of the CNV DWP and this SSCNVMP, communications triggers and protocol The modern multi-level terraced apartment building features basement car parking beneath three levels of apartments with balconies on all sides. The car parking basement is block and concrete tilt slab construction. The apartments above are a built with a timber structure. There are 42 apartments in total. Figures B.1 –B.7 in Appendix B of the Mt Eden Enabling Works CNV DWP shows that the south and west façades are predicted to be exposed to noise levels between 75 –80 dB L Aeq during the closest demolition, bored piling, rock breaking and vibro piling activities, exceeding the 75 dB L Aeq noise limit. Activity specific mitigation and management measures are included in Section 9 of the CNV DWP and not repeated here (e.g. Section 9.7 concrete and rock breaking and 9.8 piling). The top floor apartments (most exposed to site noise) are primarily occupied by university students. Mr Brown commented that the scheduling of blasting activities, indicatively timetabled for February –March 2020, would avoid normal exam study periods. There are 5 families, but only one is located on the most exposed western façade at first level. The perimeter site hoardings will effectively mitigate noise for this family. The building façade features fibre cement cladding, well-sealed operable glazing and a flat steel roof. The estimated sound level difference across the façade with the windows and doors closed is 25 –30 decibels. The predicted construction noise effects from Table 12-1 in

Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs

Section 12.1 are predicted to be typically acceptable, but with the potential for some disturbance in the apartments on the south and west façades during the demolition, portal construction and rock removal works. Physical receiver mitigation, such as temporary relocation of affected receivers, alternative ventilation and façade sound insulation improvements, have been considered, but are not required as part of the BPO for the C3 enabling works. Preliminary vibratory roller and blasting vibration level predictions (Sections 6.2 and 6.3 of the Enabling Works CNV DWP) identify that there is potential to exceed the residential cosmetic building damage thresholds. Cosmetic building damage effects are deemed ‘minor damage’ in the DIN Standard (Section 5.2), such as cracking in paint or plasterwork, and can generally be easily repaired. A pre-construction building condition survey in accordance with CRL designation condition 46 has been undertaken ensure any damage is identified for remediation.

Mr Brown agreed that prior communication of timeframes for works with the potential to exceed the relevant noise limits was an acceptable means of managing effects. No further activity specific consultation is necessary over and above regular communication (Section 10).

Mt Eden Main Works

None required for the Mt Eden Station Main Works. However, noting Mr Brown previously agreed that prior communication of timeframes for works with the potential to exceed the relevant noise limits was an acceptable means of managing effects. No further activity specific consultation is necessary over and above regular communication (Section 10).

C3.3 Review Process

If Mr Brown or affected site representatives request consultation in the future, this SSCNVMP will be updated in accordance with CRL designation conditions 37.5 and 38.5, with consideration given to the following:

The extent to which noise may exceed the designation standards

The timing and duration of any exceedance

The type of activity causing any exceedance

A summary of the communication and consultation with the receiver

The methods and measures to mitigate effects

A statement of why they reflect best practicable option Communications records are contained in the communication and consultation plan (CCP). This SSCNVMP will be updated to summarise engagement and any agreed site-specific measures.

Page 20 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs