BOTANY BAY CABLE PROJECT

Transcription

1 BOTANY BAY CABLE PROJECT CONSTRUCTION & OPERATIONAL NOISE ASSESSMENT REPORT NO VERSION A

2 BOTANY BAY CABLE PROJECT CONSTRUCTION & OPERATIONAL NOISE ASSESSMENT REPORT NO VERSION A SEPTEMBER 2006 PREPARED FOR MOLINO STEWART PTY LTD 38 COWPER STREET PARRAMATTA NSW 2150

3 Report No Version A TABLE OF CONTENTS Page EXECUTIVE SUMMARY 1 1 INTRODUCTION The Project Area Description Acoustic Terminology 4 2 AMBIENT NOISE LEVELS Long-Term Noise Logging Operator Attended Noise Monitoring 7 3 ACOUSTIC PERFORMANCE CRITERIA Construction Noise Criteria Industrial Noise Criteria Intrusiveness Criterion Amenity Criterion Determination of Site Specific Industrial Noise Criteria 10 4 NOISE SOURCE LEVELS Construction Noise Sources Operational Noise Sources 13 5 CONSTRUCTION NOISE ASSESSMENT Trenching and Cable Laying Horizontal Directional Drilling (HDD) Marine Trenching and Cable Laying Sub Station Building Works Kurnell STS Works Bunnerong STS Works 17 6 OPERATIONAL NOISE ASSESSMENT 18 7 CONSTRUCTION NOISE MANAGEMENT MEASURES Construction Noise Mitigation Measures Community Liaison & General Approaches to Mitigation Noise Management Plan 22 8 SUMMARY OF RECOMMENDATIONS Noise Criteria Construction Noise 23

4 Report No Version A 8.3 Operational Noise 24 9 CONCLUSION REFERENCES 25 APPENDIX A Glossary of Terms APPENDIX B Noise Measurement Results

5 Report No Version A Page 1 EXECUTIVE SUMMARY The following acoustic report has been prepared in relation to the proposed Botany Bay Cable Project that is to extend cabling between the Bunnerong and Kurnell Sub-Stations. The route is bounded by residential and industrial properties. The report sets out the design criteria and control concepts in relation to: Construction noise Sub-Transmission Station (STS) operational noise Noise criteria have been established for the construction and operational stages of the development, based on recommendations by the NSW Department of Environment and Conservation. During the trenching phase, initial calculations indicate the construction noise criteria are likely to be exceeded at residences in close proximity to the route. Exceedances of construction noise criteria are quite common for construction projects and given the relatively short duration of construction work compared to the life of the development, some tolerance is usually expected. Nevertheless, best practice noise management techniques should be adopted to ensure that all construction plant are in good working order. At the Drilling (HDD) site, exceedance of relevant criteria is also predicted. As the plant at this location will be stationary, there is much more scope for noise control than in the case of moving construction equipment. Noise control measures that can be adopted include a noise barrier around the compound and the provision of enclosures around the individual items of plant. It is important that any future contractor identifies specific noise control measures that will reduce noise at residences to acceptable levels. Predicted noise associated with marine cable lying indicates that noise from marine operations will be well below criteria at residences in La Perouse at all times. In the case of the residences at the northern end Prince Charles Drive a 4 dba exceedance of is predicted when the barge is at the nearest point. This exceedance is considered marginal given that much of the time the barge will be working at a greater distance from the shore. Building works are to be conducted at both STSs at Kurnell and Bunnerong. At Kurnell an exceedance of 6 dba is predicted at the nearest residences due to this activity. Mitigation of this noise can be achieved by the installation of a plywood barrier on the northern end of the STS construction site. At Bunnerong STS, construction noise is likely to be inaudible at the nearest residences. Noise from the operation for new facilities at Kurnell STS (i.e. transformers) has been determined to meet acceptable noise levels at nearby residences. The noise levels from final selected plant should be checked against the noise levels used in this report to ensure the envisaged acoustic outcome is realised..

6 Report No Version A Page 2 1 INTRODUCTION Wilkinson Murray Pty Limited has been engaged by Molino Stewart Pty Ltd to provide a construction and operational noise assessment in relation to the new 132 KV cable project. This report describes the assessment and management of noise in relation to: construction noise emissions; and noise emissions from the operation of upgraded sub-transmission stations. The issue of vibration being a significant issue for this project has been reviewed but it has been concluded it would not be for the following reasons: During construction, the major possible source of vibration is a rock breaker. This would be used only intermittently, if at all. Our measurements on previous projects indicate that vibration from a typical rockbreaker will be within recommended criteria for a residence during the daytime if the residence is 10m from the rockbreaker. Given that the nearest residence to any construction work is a distance of 15m, vibration impacts from construction can be considered insignificant. The only potential vibration impact from operational sources would from the proposed additional transformers. These are at least 150m from the nearest residences, at which distance vibration will be imperceptible. Accordingly it has been determined that vibration is not an issue for this Project and has not been dealt with further in this report. 1.1 The Project During the next decade Energy Australia must replace ageing infrastructure in the Sydney CBD and the inner metropolitan area. It has been identified that replacement of two existing high voltage feeders which currently connect Energy Australia s Bunnerong subtransmission substation ( STS ) at Matraville with its Canterbury STS at Earlwood, must be achieved by late The preferred replacement for the feeders, known as Feeders 908 and 909, however, is a new connection between Bunnerong and Kurnell across Botany Bay. It is proposed that the new feeders would take the following route: from Bunnerong STS, following the road alignments to La Perouse (3.2km); under the National Park at La Perouse by way of horizontal directional drilling (0.5km); across Botany Bay by way of submarine cable to a section of Silver Beach situated outside (but next to) the National Park at Kurnell (2.2km); and from Silver Beach to Kurnell STS, following the road alignments (1.5km). At Bunnerong STS, little work is proposed other than the laying of the cables within the site and connecting them to new terminations and existing equipment/apparatus. The new connections would provide an opportunity to upgrade Kurnell STS so that supplies to the Kurnell Peninsula are more secure, as well as facilitating the additional power into the CBD and inner metropolitan area. The proposed works at the Kurnell STS comprise:

7 Report No Version A Page 3 Replacement of the ageing outdoor high voltage switch gear with a building to house the Gas Insulated Switchgear and Control and Protection equipment to which the new cables would be connected. Three new transformers in new transformer bays. An underground retention system which would capture any oil spilled in the unlikely event of rupture of a transformer. The Project will be known as the Botany Bay Cable Project and the location of the proposed works is shown in the following figure. The total construction time is anticipated to be 12 months. In terms of the various route sections, the time breakdown is as follows. Land trenching of feeders on land 5 months Directional Drilling 4 6 months Submarine cables 2 months 1.2 Area Description The route for the cable occurs within two distinct areas separated by the entrance to Botany Bay. Northern Section This area consists of predominately residential areas of La Perouse, Phillip Bay and Chifley that are to the East of Bunnerong Road. In addition an industrial bulky goods type area is located around Bunnerong STS. Whilst this area is industrial in nature, it does not exhibit the noise generating characteristics of nearby heavy industry and port operations at Port Botany. Major contributors to noise levels in the Northern section include traffic on Bunnerong Road, ocean noise and flights to and from Sydney airport. Southern Section - This area is relatively flat in nature and residential areas are located adjacent to the heavy industry associated with the oil refinery. As such noise in this area results from industrial noise and traffic on Captain Cook drive.

8 Report No Version A Page 4 Figure 1-1 Proposed Route Showing Surrounding Residences & Noise Measurement Locations Noise Logger 1 Noise Logger 2 Noise Logger Acoustic Terminology The following report uses specialist acoustic terminology. An explanation of common terms is provided in Appendix B.

9 Report No Version A Page 5 2 AMBIENT NOISE LEVELS Long-term noise logging along with operator attended noise logging was conducted along the route. The results are detailed in the following sections. 2.1 Long-Term Noise Logging Long-term ambient noise levels were monitored at three locations around the site, selected to cover the range of environments in the potentially-affected areas. The locations are presented in Table 2-1. The logger locations are shown in Figures 2-1 to Figure 2-3 Table 2-1 Long-Term Noise Monitoring Locations Site Address Relevant Noises Noted on Site Visits Anzac Parade, La Perouse Ocean and Local Traffic 2 10 Prince Charles Parade, Kurnell Occasional local traffic, Distant Port Activity 3 26 Tasman St Kurnell Captain Cook Drive traffic; Industrial Noise from Refinery Figure 2-1 Noise Logger Site 1 adjacent to the Anzac Parade near the Northern Drilling Site Drilling Site

10 Report No Version A Page 6 Figure 2-2 Noise Logger Site 2 north of Kurnell Sub-Station Kurnell Sub -Station Figure 2-3 Noise Logger Site 3 at the top of the Kurnell end of the Site

11 Report No Version A Page 7 In all cases, noise monitoring was conducted between Friday, 21 July and Friday, 28 July The noise monitoring equipment used for these measurements consisted of environmental noise loggers set to A-weighted, fast response, continuously monitoring over 15-minute sampling periods. This equipment is capable of remotely monitoring and storing noise level descriptors for later detailed analysis. The equipment calibration was checked before and after the survey and no significant drift was noted. The logger determines L A1, L A10, L A90 and L Aeq levels of the ambient noise. L A1, L A10 and L A90 are the levels exceeded for 1%, 10% and 90% of the sample time respectively (see Appendix A for definitions). The L A1 is indicative of maximum noise levels due to individual noise events such as the occasional pass-by of a heavy vehicle. The L A90 level is normally taken as the background noise level during the relevant period. Detailed results for each monitoring location are shown in graphical form in Appendix B. The graphs show measured values of L Aeq, L A90, L A10 and L A1 for each 15-minute monitoring period. Table 2-2 summarises the results, for daytime, evening and night time periods as defined in the NSW Department of Environment & Conservation s (DEC) NSW Industrial Noise Policy (INP). The summary values are: L Aeq,Period the overall L Aeq noise level measured over the assessment period; and RBL Rating Background Level is a measure of typical background noise levels which are used in determining noise criteria. Table 2-2 Summary of Measured Noise Levels Noise RBL (dba) L Aeq, Period (dba) Logging Site Daytime 7am-6pm Evening 6-10pm Night Time 10pm-7am Daytime 7am-6pm Evening 6-10pm Night Time 10pm-7am The values shown in Table 2-2 are considered typical for the relevant areas. 2.2 Operator Attended Noise Monitoring In addition to long-term noise monitoring, a number of operator attended noise measurements were conducted along the route in nearby residential areas. These measurements consisted on 15-minute noise sample during normal daytime hours. The purpose of the measurements was to ensure that there are no areas along the route that are subject to a significant variance from the results determined from noise logging. Table 2-3 presents the results of these measurements on the southern side of the route.

12 Report No Version A Page 8 Table 2-3 Noise Measurement on Southern Kurnell Side of Route Location Time L Aeq L90 9 Bridges Street 12: Silver Beach Road 12: Prince Charles Parade 13: In summary, the results revealed that background noise levels along the southern route during measurements were: 48 52dBA These levels compare to established RBL s of 41 and 42dBA at Locations 2 and 3 respectively. It is considered that the higher operator attended measurements are likely to be the result of daily variations indicating that adoption of criteria based on the noise logging results is acceptable and appropriate. Table 2-4 presents the results of these measurements on the northern side of the route. Table 2-4 Noise Measurements on Northern La Perouse Side of Route Location Time L Aeq L90 2 Grose Street 8: Cnr Bunnerong and Yarra 9: Hastings Avenue 9: Wassell Street 14: In summary the results revealed that background noise levels along the route during measurements were: dba These levels compare to establish RBL of 43dBA at Location 1. It is considered that the adoption of the Location 1 result is generally consistent with operator attended measurements and this noise level should be used in establishing criteria along the northern route.

13 Report No Version A Page 9 3 ACOUSTIC PERFORMANCE CRITERIA The following sections detail the applicable site specific noise criteria based on the guidelines of the DEC. 3.1 Construction Noise Criteria The assessment of construction noise is dependent on the duration of construction in the vicinity of the potentially affected residential receiver. The Department of Environment and Conservation in Chapter 171 of the Environmental Noise Control Manual (ENCM) suggests the following noise control guidelines. Level Restrictions (i) (ii) Construction period of 4 weeks and under. The L 10 level measured over a period of not less than 15 minutes when the construction site is in operation must not exceed the background level by more than 20 db(a). Construction period greater than 4 weeks and not exceeding 26 weeks. The L 10 level measured over a period of not less than 15 minutes when the construction site is in operation must not exceed the background level by more than 10 db(a). Time Restrictions Monday to Friday Saturday 7am 6pm 7am 1pm (if inaudible at residential premises) 8am 1pm (if audible at residential premises) No construction work to take place on Sundays or Public Holidays Silencing All possible steps should be taken to silence construction site equipment. It is particularly important that silenced equipment should be used on road or rail works where 24 hour operation is necessary. Where the construction period is likely to be over 26 weeks, a construction noise goal based on a background + 5dBA approach is usually adopted. Table 3-1 presents the applicable construction noise criteria. Table 3-1 Construction Noise Criteria - dba Receiver Area Construction Duration (Daytime) Up to 4 weeks 4 to 26 weeks > 26 weeks

14 Report No Version A Page Industrial Noise Criteria The only site where additional noise producing equipment is proposed is at the Kurnell Substation where new transformers are to be brought on line. Therefore operational noise criteria have been established only for this site, based on noise measurements at that location. The NSW Industrial Noise Policy (INP) recommends two criteria, Intrusiveness and Amenity, both of which are relevant for the assessment of noise. In most situations, one of these is more stringent than the other and dominates the noise assessment. The criteria are based on the L Aeq descriptor, which is explained in Appendix B Intrusiveness Criterion An intrusiveness criterion applies for residential receivers only. The intrusiveness criterion requires that the L Aeq noise level from the source being assessed, when measured over 15-minutes, should not exceed the Rating Background Noise Level (RBL) by more than 5dBA. The RBL represents the background noise in the area, and is determined from measurement of L A90 noise levels, in the absence of noise from the source. The definition of L A90 and RBL is given in Appendix A. Where the noise level from the source varies over time due to changes in operating conditions, meteorological conditions or other factors, the upper 10 th percentile of 15-minute L Aeq noise levels can be used for comparison with the criterion Amenity Criterion The amenity criterion sets a limit on the total noise level from all industrial noise sources affecting a receiver. Different criteria apply for different types of receiver (e.g. residence, school classroom); different areas (e.g. rural, suburban); and different time periods, namely daytime (7.00am-6.00pm), evening (6.00pm-10.00pm) and night time (10.00pm-7.00am). The noise level to be compared with this criterion is the L Aeq noise level, measured over the time period in question, due to all industrial noise sources, but excluding non-industrial sources such as transportation. Where a new noise source is proposed in an area with negligible existing industrial noise, the amenity criterion for that source may be taken as being equal to the overall amenity criterion. However, if there is significant existing industrial noise, the criterion for any new source must be set at a lower value. If existing industrial noise already exceeds the relevant amenity criterion, noise from any new source must be set well below the overall criterion to ensure that any increase in noise levels is negligible. Methods for determining a source-specific amenity criterion where there is existing industrial noise are set out in the INP Determination of Site Specific Industrial Noise Criteria Table 3-2 presents the relevant industrial noise criteria for this project based on an urban area classification.

15 Report No Version A Page 11 Table 3-2 Industrial Intrusiveness & Amenity Criteria Receiv er Area Time Period RBL (dba) Intrusiveness Criterion L Aeq,15min (dba) Level of Existing Industrial Noise, L Aeq,period Project- Specific Amenity Criterion 3 Daytime (7.00am 6.00pm) Evening ( pm) Night time (10.00pm 7.00am) In this case, there is industrial noise existing in the area associated with the Caltex refinery and other surrounding facilities. Operational noise from the site would be present on a 24-hour basis, and as a result the night-time amenity criterion of 43dBA will in effect be the controlling noise criterion on site.

16 Report No Version A Page 12 4 NOISE SOURCE LEVELS Noise sources that are likely to be associated with the construction and operation of the development are identified in the following sections. 4.1 Construction Noise Sources Typical Sound Power Levels (SWL) of the plant likely to be used during earthworks, construction and cable laying are identified in Table 4-1. These SWLs have recently been measured at other similar construction sites. Table 4-1 Typical Construction Plant Sound Power Levels (SWL) Plant SWL, dba Excavator 107 Dump Trucks 112 Rock Breaker 122 Concrete Trucks 112 Saws 116 Saw Cutter 115 Small Excavators 90 Water Truck 110 Vibratory Rollers 110 Concrete Trucks 109 Dozer 119 Graders 109 Smooth Drum Roller 107 Small Generators 95 Front End - Low Loader 112 Compressor 100 Large Diesel Water Pump 112 Tug Boat 108 Table 4-2 Typical HDD Construction Plant Sound Power Levels (SWL) Plant SWL, dba Excavator 107 Power Pac (Treated) 100 Mud Pumps 110 Generators 110 Vertical Sump Pumps 83

17 Report No Version A Page Operational Noise Sources Typical noise sources associated with the transformer proposed for the Kurnell Sub-Station are shown in Table 4-3. This data has been supplied by the transformer manufacturer Wilson. Table 4-3 Transformer Sound Power Levels (SWL) Transformer Type SWL (dba) 132KV-33KV KV-11KV 71

18 Report No Version A Page 14 5 CONSTRUCTION NOISE ASSESSMENT Assessment of likely construction noise has been based on the four main construction operations that are proposed. These construction activities will be spread out over a large distance. As such each area can be assessed separately, as noise from each operation will not be cumulative at a particular residence. Operations are: Trenching and Cable Laying Horizontal Directional Drilling (HDD) at the La Perouse Site Marine Trenching and Cable Laying across the heads to Botany Bay Sub Station Building Works at Kurnell and Bunnerong STSs All operations are to be conducted during normal construction hours, as detailed in Section 3.1, thereby affording residences respite from any construction noise during night periods and on Sundays. The operations are assessed in the following sections: 5.1 Trenching and Cable Laying This construction process consists of cutting and excavation a trench in the roadway to lay cable along the specified route. With the exception of the sandstone section between the HDD site and Elaroo Road all excavation will be in sand. As such the excavation, laying and filling process with be relatively short - it is anticipated that residences along the cable route will be exposed to construction noise for less than 4 weeks. The trenching is likely to be conducted in 500 m lengths on the southern section and 1000 m lengths on the northern side of the site. In the section between the La Perouse HDD site and Elaroo Avenue a rock saw will be required to cut the trench. Predicted noise levels at residences are based on the equipment considered likely to be operating during any 15-minute period, which are: Excavator for 10-minutes Dump Truck for 5-minutes Rock Saw for 5-minutes (for the La Perouse to Elaroo Avenue rock section only) This results in overall plant sound power levels of 109dBA and 113dBA for the sand and rock trenching lengths respectively, and noise levels at residences along the route have been predicted on this basis. The noise predictions are based on distance attenuation and noise shielding provided by any topographical features. The following Table 5-1 presents the predicted likely construction noise levels due to trenching at nearby residences along the route.

19 Report No Version A Page 15 Table 5-1 Predicted Noise Levels at Residences along Trench Route - dba Section Distance to Residences Distance Atten Barrier Resultant Criteria Exceedance Kurnell STS to Capt Cook Drive 35m Silver Beach Road 15m Prince Charles Parade 16m HDD Site to Elaroo Avenue 20m Canara Avenue 21m Little Bay Road 200m Willis Street 130m Wassell Street 90m These initial calculations indicate the construction noise criteria are likely to be exceeded during the trenching phase at residences in close proximity to the route. Exceedances of construction noise criteria are quite common for construction projects, and given the relatively short duration of construction work compared to the life of the development, some tolerance is usually expected. It is recommended that the use of rock breakers be avoided, with rock saws being preferred. This is particularly significant in the section from Goorawahl Avenue to Elaroo Avenue where the trench is to be cut into rock. Further, best practice noise management techniques should be adopted to ensure that all plant is in good working order. Noise management is address later in this report. 5.2 Horizontal Directional Drilling (HDD) The horizontal direction drilling will be performed by a number of items of plant located in a site compound. This compound will be of a significant size to accommodate the following likely plant: 2 x Power Packs (in acoustic containers) 2 x Generators 1 x HDD Drilling Unit 3 x mud pumps 5 x vertical sump pumps In addition, occasional equipment delivery and dumps trucks will visit the site. It is envisaged that the HDD site will operate for a period up to six months.

20 Report No Version A Page 16 Based on the equipment noise levels presented in Table 4-2, the total sound power level of equipment on site will be in the order of 118dBA. Accordingly, a resultant construction noise level of 78dBA is predicted at nearby residences to the north and west of the site, assuming the HDD site is located on the old tram roundabout site. A reduction in construction noise of 25dBA is required to comply with the established 4 26 week noise criterion of 53dBA. Noise control measures that can be adopted to reduce noise levels at residences are: install a noise barrier around the compound on the side facing residences practically reductions in the order of 10 15dBA can be achieved; provide enclosures around the individual items of plant. It is likely that a combination of the above measures will be required to ensure the acoustic amenity of nearby residence is protected during this stage of the project. Being stationary plant, there is much more scope for noise controls than for moving construction equipment. As a result of this assessment it is important that any future contractor identifies specific noise control measures that will achieve the required noise levels at residences. 5.3 Marine Trenching and Cable Laying Noise associated with marine cable lying will result from equipment mounted on a barge that will be manoeuvred by a tug boat. Items of plant likely to be associated with this construction process are: Tug boat 2 x Power Packs (in acoustic containers) 750 Hp water pump (Diesel) Compressor. A sound power level of 111dBA has been established for the barge equipment and tug. Maximum construction noise levels associated with marine cable laying operations are predicted to be: La Perouse residences - 36dBA (Assumes a closest distance of 380m at nearest point and shielding provided the by headland) Prince Charles Drive residences 65dBA (Assumes a distance of 80m at nearest point) The noise predictions indicate that noise from marine operations will be well below the noise criteria at residences in La Perouse at all times. In the case of the residences on Prince Charles Drive nearest to the marine section of cable, a 4dBA exceedance of noise goals is predicted at the nearest point. This exceedance is considered marginal given that much of the time the barge will be working at a greater distance from the shore. Accordingly, the noise associated with the barge is considered manageable. It is recommended that noise from plant associated with the barge operations is reviewed at assembly to ensure

21 Report No Version A Page 17 that noise emissions are in accordance with these findings. 5.4 Sub Station Building Works Building works are to be conducted at both STSs at Kurnell and Bunnerong. The following sections detail the likely construction works and the associated noise emissions: Kurnell STS Works Work will consist of: construction of two new buildings, one each for the 32 and 11 KV switch gear; and construction of footings, slab and blast walls for new KV transformers. Predicted noise levels at residences are based on the following equipment operating during any likely 15 minute period: Excavator for 10-minutes Concrete Truck for 10-minutes Dump Truck for 5-minutes. Small Compressor on site for 15-minutes Based on a total sound power level of 110 dba, the resultant construction noise levels at residences on Tasman Road are predicted to be in the order of 58dBA. This noise level represents an exceedance of the 4 26 week noise goal of 52dBA by 6dBA. Mitigation of noise from these activities can be achieved by the installation of a plywood barrier or hoarding on the northern end of the STS construction site. A barrier in the order of 2 2.5m should provide sufficient noise reduction to result in general compliance with the established noise criteria Bunnerong STS Works Proposed construction works at Bunnerong STS consist of the construction of footings for new circuit breakers and isolators. The construction equipment used in these operations will be similar to the Kurnell STS works; however the period of these works will be in the order of 2 3 months. Resultant noise levels at the nearest residences to this site, being residences in Moorina Avenue at a distance of 350m, are predicted to be in the order of 36dBA. This level is likely to be inaudible at these residences.

22 Report No Version A Page 18 6 OPERATIONAL NOISE ASSESSMENT The Kurnell Sub-Station will be upgraded to accommodate the new cables. The upgrade will include the following transformers: An existing Wilson KV transformer This transformer is located adjacent to the two existing transformers already operating on site. The transformer shown in Figure 6-1 is to be connected to the grid. This unit will service as a backup to the two existing units. Three new Wilson KV transformers are to be installed in an extension of the existing substation. These transformers illustrated in Figure 6-2 will be located on the northern side of the site. Figure 6-1 Existing KV Transformer to be brought on line

23 Report No Version A Page 19 Figure 6-2 A KV Transformer A worst case prediction of operational noise levels at the nearest residential receivers to the north on Tasman Street has been conducted based on ALL additional transformers operating simultaneously. Predictions are based on: Equipment Noise Levels As supplied by Wilson. Distance attenuation over m. Based on the above, the overall contributed noise level associated with the new transformers will be in the order of 26dBA. In addition, application of a penalty of 5dB, to allow for a 100 Hz tonal component that is typically exhibited by transformers, can be applied to the predicted noise levels. When comparing the total adjusted operational noise with the night time criterion of 43dBA compliance is indicated.

24 Report No Version A Page 20 Figure 6-3 New Transformer Locations at Kurnell STS Tasman Road Residences 3 x KV Transformers KV Transformer

25 Report No Version A Page 21 7 CONSTRUCTION NOISE MANAGEMENT MEASURES 7.1 Construction Noise Mitigation Measures Without mitigation, noise levels from some construction activities have been predicted to exceed the nominated design goals at some residential receivers. Therefore, noise control measures have been recommended to ensure that acceptable levels are achieved at affected residences. A range of possible approaches to reducing the impact of construction noise is described below. It is proposed that these strategies be applied to areas of exceedance identified in the preceding section. Noise Monitoring Programme A well-planned noise monitoring programme will assist in identifying the site-specific potential for disturbance at particularly sensitive localities as the works progress. Mitigation measures such as changes in work sequences or selection of smaller items of equipment can then be put in place before significant disturbance occurs. The programme would include the ongoing monitoring of emissions from work sites and would assist in planning of ongoing works. Noise Sensitive Sites The quietest available plant and equipment that can economically undertake the work required should be selected. Mobile plant such as excavators, front-end loaders and other diesel-engined equipment should be fitted with residential class mufflers and other silencing equipment, as applicable. Plant Noise Audit Noise emission levels of all critical items of mobile plant and equipment should be checked for compliance with noise limits appropriate to those items prior to the equipment going into regular service. Periodic noise monitoring should be conducted to ensure that items of plant continue to be well maintained in compliance with the noise emission limits for that class of equipment. To this end, a regular testing programme should be established with the contractor. Operator Instruction Operators should be trained in order to raise their awareness of potential noise problems and to increase their use of techniques to minimise noise emission. Equipment Selection - All fixed plant at the work sites should be appropriately selected, and where necessary, fitted with silencers, acoustical enclosures and other noise attenuation measures in order to ensure that the total noise emission from each work site complies with EPA guidelines. It is likely that the HDD site will need to be significantly treated. Site Noise Planning - Where practical, the layout and positioning of noise-producing plant and activities on each work site should be optimised to minimise noise emission levels. Permissible Times of Work - The hours of use of noisy equipment may be limited at the work sites where residential areas could otherwise be adversely affected. However, the implications of this in terms of possible extension of the period of noise exposure should be considered.

26 Report No Version A Page Community Liaison & General Approaches to Mitigation An effective community relations programme should be put in place to keep the community that has been identified as being potentially affected appraised of progress of the works, and to forewarn potentially affected groups (e.g. by letterbox drop, meetings with community groups, etc) of any anticipated changes in noise emissions prior to critical stages of the works, and to explain complaint procedures and response mechanisms. Close liaison should be maintained between the communities overlooking work sites and the parties associated with the construction works to provide effective feedback in regard to perceived emissions. In this manner, equipment selections and work activities can be coordinated where necessary to minimise disturbance to neighbouring communities, and to ensure prompt response to complaints, should they occur. 7.3 Noise Management Plan A Noise Management Plan should be included in the Environmental Management Plan for the project. The plan should be prepared during the project planning process, including components relating to noise. This plan should detail the mitigation, monitoring and community liaison measures. The plan will be updated to incorporate any additional measures that emerge as the project design evolves and work methodologies become better defined. Areas that should be addressed in plan include: Noise Monitoring Response to Complaints Responsibilities Monitoring of Noise Emissions from Plant Items Supplementary Noise Monitoring and Long Term Noise Monitoring Reporting and Record Keeping Non Compliance and Corrective Action Community Consultation and Complaint Handling

27 Report No Version A Page 23 8 SUMMARY OF RECOMMENDATIONS Based on our investigations of the project the following recommendations have been established. 8.1 Noise Criteria Noise criteria for construction and operation have been established based on noise measurements processed in accordance with DEC procedures. These noise criteria should be adopted as objectives to work towards in minimising noise impact at surrounding residences. 8.2 Construction Noise Noise from construction activities will potentially exceed established noise goals. Therefore, the planning and management of construction activities should take into account the sensitivities of surrounding residents to minimise the impact of construction noise at these receivers. The following Table 8-1 summarises the findings of the construction noise assessment. Table 8-1 Summary of Construction Noise Findings Activity Findings Comments / Recommendation Trenching and Cable Laying Exceedances up to 16dBA are Noise impact is greatest at residences in close proximity to the route. Noise impact is mitigated by short time period of construction. predicted whilst equipped is adjacent Best practice noise management of to residences along route plant should be adopted. Avoid the use of rock breakers in preference to rock saws. Horizontal Directional Drilling Exceedances up to 25dBA are predicted at adjacent to residences Site and equipment will require significant noise controls to be adopted by successful contractor. Barriers / Hoarding are required. Treatment to plant likely to be required. Marine Trenching and Cable Laying General compliance except when barge is adjacent to Prince Charles Parade Small exceedance predicted. Much of the time the barge will be working at a greater distance from the shore. Noise of plant associated with the barge operations should be reviewed at assembly.

28 Report No Version A Page 24 Activity Findings Comments / Recommendation Kurnell STS Works Bunnerong STS Works Exceedances up to 6dBA are predicted at Tasman Street Residences No exceedance of criteria is indicated Install a 2 2.5m high plywood barrier / hoarding on the northern end of the STS construction site. Construction noise likely to be inaudible at residences. The control of construction noise should form a part of the site Environmental Management Plan where best practice procedures and community consultation is employed. 8.3 Operational Noise Noise from the operation for new facilities at Kurnell STS (i.e. transformers) has been determined to meet acceptable noise levels at nearby residences. The noise levels of final plant should be checked against the noise levels used in this report ensures the envisaged acoustic outcome is achieved.

29 Report No Version A Page 25 9 CONCLUSION This assessment of the Botany Cable Project has established noise criteria appropriate for construction and operational noise based on ambient noise monitoring. A combination of engineering and management measures is required to minimise noise emissions. Engineering measures recommended include noise barriers and enclosures. Construction activities are likely to exceed established goals along the trenching route and adjacent to the HDD site. Accordingly management of this issue will require attention in minimising the acoustic impact at residences. The required measures have been discussed in sufficient detail in this report to allow detailed design of engineering modifications and inclusion of noise management measures in the site operating procedures. It should be noted that other noise mitigation measures are usually available although this report recommends strategies considered to be the most practical and cost effective for this application. Noise from the operation of additional plant at the Kurnell STS has been assessed and it has been determined that compliance with DEC noise criteria will be achieved. 10 REFERENCES NSW Department of Environment & Conservation (DEC), 2001 NSW Industrial Noise Policy Note All materials specified by Wilkinson Murray Pty Limited have been selected solely on the basis of acoustic performance. Any other properties of these materials, such as fire rating, chemical properties etc. should be checked with the suppliers or other specialised bodies for fitness for a given purpose. Quality Assurance We are committed to and have implemented AS/NZS ISO 9001:2000 Quality Management Systems Requirements. This management system has been externally certified and Licence No. QEC has been issued. AAAC This firm is a member firm of the Association of Australian Acoustical Consultants and the work here reported has been carried out in accordance with the terms of that membership. Version Status Date Prepared by Checked by B Draft 6 September 2006 Brian Clarke Rob Bullen

30 APPENDIX A GLOSSARY OF TERMS

31 Report No Version A Appendix A-1 GLOSSARY Most environments are affected by environmental noise which continuously varies, largely as a result of road traffic. To describe the overall noise environment, a number of noise descriptors have been developed and these involve statistical and other analysis of the varying noise over sampling periods, typically taken as 15 minutes. These descriptors, which are demonstrated in the graph overleaf, are here defined. Maximum Noise Level (L Amax ) The maximum noise level over a sample period is the maximum level, measured on fast response, during the sample period. L A1 The L A1 level is the noise level which is exceeded for 1% of the sample period. During the sample period, the noise level is below the L A1 level for 99% of the time. L A10 The L A10 level is the noise level which is exceeded for 10% of the sample period. During the sample period, the noise level is below the L A10 level for 90% of the time. The L A10 is a common noise descriptor for environmental noise and road traffic noise. L Aeq The equivalent continuous sound level (L Aeq ) is the energy average of the varying noise over the sample period and is equivalent to the level of a constant noise which contains the same energy as the varying noise environment. This measure is also a common measure of environmental noise and road traffic noise. L A50 The L A50 level is the noise level which is exceeded for 50% of the sample period. During the sample period, the noise level is below the L A50 level for 50% of the time. L A90 The L A90 level is the noise level which is exceeded for 90% of the sample period. During the sample period, the noise level is below the L A90 level for 10% of the time. This measure is commonly referred to as the background noise level. ABL The Assessment Background Level is the single figure background level representing each assessment period (daytime, evening and night time) for each day. It is determined by calculating the 10 th percentile (lowest 10 th percent) background level (L A90 ) for each period. RBL The Rating Background Level for each period is the median value of the ABL values for the period over all of the days measured. There is therefore an RBL value for each period daytime, evening and night time. DEC NSW Department of Environment & Conservation INP NSW Industrial Noise Policy ECRTN Environmental Criteria for Road Traffic Noise

32 Report No Version A Appendix A Sound Pressure Level (dba) L Amax L A1 L A10 L Aeq L A50 L A :00 3:00 6:00 9:00 12:00 15:00 Monitoring or Survey Period (5 sec samples)

33 APPENDIX B NOISE MEASUREMENT RESULTS

34 Report No Version A Appendix B-1 Location: Anzac Parade Fri 21 Jul 06 Sat 22 Jul 06

35 Report No Version A Appendix B-2 Location: Anzac Parade Sun 23 Jul 06 Mon 24 Jul 06

36 Report No Version A Appendix B-3 Location: Anzac Parade Tue 25 Jul 06 Wed 26 Jul 06

37 Report No Version A Appendix B-4 Location: Anzac Parade Thu 27 Jul 06 Fri 28 Jul 06

38 Report No Version A Appendix B-5 Location: Anzac Parade Sat 29 Jul 06 Sun 30 Jul 06

39 Report No Version A Appendix B-6 Location: Anzac Parade Mon 31 Jul 06

40 Report No Version A Appendix B-7 Location: 2-10 Prince Charles Parade, Kurnell Fri 21 Jul 06 Sat 22 Jul 06

41 Report No Version A Appendix B-8 Location: 2-10 Prince Charles Parade, Kurnell Sun 23 Jul 06 Mon 24 Jul 06

42 Report No Version A Appendix B-9 Location: 2-10 Prince Charles Parade, Kurnell Tue 25 Jul 06 Wed 26 Jul 06

43 Report No Version A Appendix B-10 Location: 2-10 Prince Charles Parade, Kurnell Thu 27 Jul 06 Fri 28 Jul 06

44 Report No Version A Appendix B-11 Location: 2-10 Prince Charles Parade, Kurnell Sat 29 Jul 06 Sun 30 Jul 06

45 Report No Version A Appendix B-12 Location: 2-10 Prince Charles Parade, Kurnell Mon 31 Jul 06

46 Report No Version A Appendix B-13 Location: 3-26 Tasman St Kurnell Fri 21 Jul 06 Sat 22 Jul 06

47 Report No Version A Appendix B-14 Location: 3-26 Tasman St Kurnell Sun 23 Jul 06 Mon 24 Jul 06

48 Report No Version A Appendix B-15 Location: 3-26 Tasman St Kurnell Tue 25 Jul 06 Wed 26 Jul 06

49 Report No Version A Appendix B-16 Location: 3-26 Tasman St Kurnell Thu 27 Jul 06 Fri 28 Jul 06

50 Report No Version A Appendix B-17 Location: 3-26 Tasman St Kurnell Sat 29 Jul 06 Sun 30 Jul 06

51 Report No Version A Appendix B-18 Location: 3-26 Tasman St Kurnell Mon 31 Jul 06