C27 5 Water Street SSCNMP

C27 5 Water Street SSCNMP

C27.1 Introduction

This Site-Specific Construction Noise Management Plan (SSCNMP) is for the commercial building located at 5 Water Street. A SSCNMP is required because construction is predicted to exceed the Project Noise Standards in CRL designation condition 31. This SSCNMP has been prepared in accordance with CRL designation condition 37 and is Appendix C27 of the Mt Eden Main Works Construction Noise and Vibration Delivery Work Plan (CNV DWP). It is a supplementary document that builds on the Project CNV DWP, and therefore directly references relevant sections of the DWP to avoid repetition. The objective of this SSCNMP is to detail the best practicable option(s) (BPO) to avoid, remedy or mitigate the identified adverse effects from noise exceedances at 5 Water Street.

This draft SSCNMP has been prepared by Marshall Day Acoustics and forms part of the Construction Environmental Management Plan (CEMP) for the Project. It builds on the SSCNMP previously prepared and implemented for the Normanby Rd Early Works.

C27.2 Engagement

Normanby Rd Early Works (for information)

Link Alliance representatives Sonya Leahy, Hilary Konigkramer and Craig Fitzgerald (Marshall Day Acoustics) met with Rhys Williams (I Measure U) on 10 October 2019. The matters discussed included:

An overview of the Normanby Road early works.

General work programme.

Overview of the CNV DWP and this SSCNMP, communications triggers and protocol. The site is used for commercial purposes, with the large open plan office space for I Measure U in a converted warehouse above basement car parking. Mr Williams key concern was vibration due to camera equipment used on-site. It was explained that the adjacent low-rise buildings would be dismantled to minimise vibration, but the concrete foundations may need to be broken up which may be perceptible. The CNV DWP has specific measures to minimise vibration. Of interest to Mr Williams was that this activity would be short in duration and advanced communication would be provided with timing of breaking works. The south and east façades are predicted to be exposed noise levels exceeding the 75 dB L Aeq noise limit from the demolition of 11 Water Street in February 2020, and the sewer trenching works adjacent to 5 Water Street in May 2020. Activity specific mitigation and management measures are included in Section 9 of the CNV DWP and not repeated here (e.g. Section 9.4 general mitigation measures). The building at 5 Water Street is a double level industrial building with blockwork façade, small sealed windows, but steel pitched roof with no internal ceiling. The estimated sound level difference across the façade with the windows and doors closed is 20 –25 decibels. The predicted construction noise effects from Table 12-1 in Section 12.1 are predicted to be typically acceptable, but with the potential for some isolated disturbance during adjacent sewer connection 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 C5 enabling works.

Page 81 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs

Page 82 Mr Williams 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 (refer Section 10). Subsequently, Craig Fitzgerald (Marshall Day Acoustics) met with Kat Kinghorn and Rakesh Vallabh (I Measure U) on 7 July 2020. Noise and vibration from adjacent demolition and rock breaking works had affected data capture quality due to induced camera shake. It was explained that previous concerns about camera vibration sensitivity were interpreted to relate to the storage of camera equipment, rather vibration effects on video capture due to camera shake. The discussion focused on addressing this residual matter. ‘Data capture’ typically involves a series of cameras setup in a circle to take 360 degree video. The setup is located on first floor level, on a suspended concrete floor. To provide context of sensitivity, walking within the room can affect data capture quality. It is understood that transient bumps (e.g. activity within the tenancy or single events on the construction site) are post edited out as a matter of course, but continuous vibration (e.g. vibro roller) can render the data set unusable. While it is the latter continuous vibration activities of primary concern, it was noted that transient events can be minimised with good site management and training (refer Section 7). The data capture is undertaken for approximately 30min –1hr every 7 –10 days. There is flexibility to arrange compatible timing to avoid close proximity works that generate continuous vibration. This would include vibro rolling/compaction, sheet piling and potentially concrete/rock breaking. It was noted that a similar arrangement was in place for Float Culture, and they preferred such works to be undertaken before midday when they had less customers. This timing would be acceptable to I Measure U. Ms Kinghorn and Mr Vallabh agreed that prior communication of timeframes for close proximity works with the potential to generate continuous vibration was an acceptable means of managing effects. No further activity specific consultation is necessary over and above regular communication (refer Section Error! Reference source not found.).

Mt Eden Main Works

Link Alliance representatives XXX met with building representative XXX on XXX date. The matters discussed included:

An overview of the next project phases

General programme, rock removal, excavation, piling, and utilities relocation activities

General review of CNV DWP and this SSCNMP, communications triggers and monitoring CNV DWP Section 7 identifies summarise the potential scale of noise and/or vibration exceedances using the modelling outputs in insert hyperlink to the GIS maps here. The relevant stages are summarised below. Activity specific mitigation and management measures are included in Section 9 of the CNV DWP, and referenced in brackets, rather than repeated.

Retaining walls (refer piling in Section 9.8) The predicted construction noise effects from Table 12.1 in Section 12.1 are predicted to result in XXX noise effects. 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 Mt Eden Station Main Works.

Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs

XXX 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).

C27.3 Review Process

If I Measure U representatives request consultation in the future, this SSCNMP will be updated in accordance with CRL designation condition 37.5, with consideration given to the following:

The extent to which noise may exceed the Project Noise 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 noise effects

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

Page 83 Mt Eden Main Works CNV DWP –Appendix C SSCNVMPs