5.0 Noise Impact

Introduction

5.1 During the construction and operation of the proposed on-site concrete batching plant, other construction works such as road works (construction of Northern Access Road, Southern Access Road, D1 and D2 roads) and main construction works will be carried out concurrently. Noise arising from these construction and operation activities are likely to create noise impacts on the surrounding NSRs. The extent of the impacts affecting the identified NSRs will vary from phase to phase depending upon the types of powered mechanical equipment (PME) used and locations of works to be carried out.

5.2 This section presents an assessment for the possible cumulative noise impacts arising from the road works, main construction work, together with the construction/operation of the proposed concrete batching plant at Telegraph Bay between December 2000 and December 2001.

Government Legislation and Standards

5.3 The Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM) provides guidance on construction noise levels at the openable windows of various types of noise sensitive buildings. The recommended noise standards are presented in Table 5.1.

Table 5.1 EIAO-TM Daytime Construction Noise Guidelines (Leq, 30min dB(A))

Land Use	Noise Standards dB(A)
Domestic Premises	75
Educational Institutions (normal periods)	70
Educational Institutions (during examination periods)	65

5.4 The target construction noise impact upon school adopted in this assessment is 65 dB(A). However, it is recongized that this target is only applicable during examinations periods, and EIAO-TM provides guidance on construction noise levels at the openable windows of various types of noise sensitive buildings.

5.5 The Noise Control Ordinance (NCO) provides statutory controls on general construction works during the restricted hours (i.e. 1900 to 0700 hours Monday to Saturday and at any time on Sundays and public holidays). The use of powered mechanical equipment (PME) for the carrying out of construction works during the restricted hours would require a Construction Noise Permit (CNP). Despite any description or assessment made in this EIA Report on construction noise aspects, there is no guarantee that a CNP will be issued for the project construction. The Noise Control Authority will consider a well-justified CNP application, once filed, for construction works within restricted hours as guided by the relevant Technical Memoranda issued under the NCO. The Noise Control Authority (NCA)will take into account of contemporary conditions / situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP. Nothing in this EIA Report shall bind the NCA in making his decision. If a CNP is to be issued, the NCA shall included in it any condition he thinks fit. Failure to comply with any such conditions will lead to cancellation of the CNP and prosecution action under the NCO.

Assessment Methodology

5.6 Noise predictions were undertaken for the Cyberport Development and its Associated Engineering Infrastructure works in accordance with the methodology outlined in the GW-TM. Additional information was obtained from “A Practical Guide to the Reduction of Noise from Construction Works’, EPD 1989 and British Standard 5228 Part 1: 1997, ‘Noise Control on Construction and Open Sites’.

5.7 A positive correction of 3 dB(A) was made to the calculated result to allow for façade effect. Also, the distance between the batching plant and noise sensitive receivers (NSRs) would be determined [D]. For distance attenuation equals to or below 300m, reference to Table 5 of the GW-TM has been made. For distance attenuation above 300m, it has been estimated using the following formula:

Distance Attenuation in dB(A) = 20 log D +8 [where D is the distance in metre]

5.8 The distance attenuation calculated from the above formula would be subtracted from the total sound power level to give the Predicted Noise Level (PNL) at the existing NSR.

5.9 This assessment presents only the impacts during normal daytime hours (07:00 – 19:00) excluding Sundays and Public Holidays work. The relevant noise criteria as stipulated in the EIAO-TM are 75 dB(A) for residential dwellings, and 70dB(A) for education institutions during normal periods and 65dB(A) during examination periods.

5.10 The construction and operation of the concrete batching plant, and the construction of the road works and main works for cyberport will be carried out concurrently and therefore assessment for the possible cumulative noise impacts from these activities are required. Since the assessment of the Northern Access Road and other main works are performed by two separate consultants. For the purpose of the cumulative assessment, the noise impacts arising from the construction of Northern Access Road and other main works have been made reference to the following two documents:

· R1: Main Work for Cyber Port Development Environmental Permit Variation Application – Construction Noise Impact Assessment (February 2000); and

· R2: Northern Access Road for Cyberport Development Environmental Permit Application – Supplementary Environmental Assessment Report (July 2000);

5.11 The mitigated noise levels at the existing NSRs during the construction of both Northern Access Road and other roads have been calculated in the above documents. The highest mitigated noise level at each of the NSR as given in Appendix 5.1 has been used for the cumulative noise predictions.

Identification of Sensitive Receivers

5.12 Twenty-two representative NSRs similar to those identified in the two documents have been selected for the cumulative noise assessment and are listed in Table 5.2.

Table 5.2 Proposed Noise Sensitive Receivers (NSRs) during Construction of Telegraph Bay Development

NSR No.	Description	Land Use*	No. of Storeys
SR2	Tam Villa	R	22
SR3	HKU Staff Quarters	R	12
SR4-8	42,45,47,50 & 60 Sasson Road	R	3
SR9	Magnolia Villas	R	3
SR10	Point Breeze	R	3
SR11	Carriana Sasson	R	3
SR12	Stone Manor	R	3
SR13	Provident Villas	R	3
SR19	16-18 Baguio Villas	R	10
SR19 a, b	45-48 Baguio Villas	R	29
SR21	Pok Fu Lam Training Centre	S	7
SR22	Pok Fu Lam Garden	R	28
SR23	Wah Fu Estate	R	21
SR24	Lui Ming Choi Secondary School	S	7
SR25	Precious Blood Primary School	S	5
SR26	Tsui Ching Tong School For the Handicap	S	6
SR27	Kong Sin Wan Tsuen	R	2-3
SR40	Pui Ying Secondary School	S	7

* Residential Uses – R, School Uses - S

Noise Impact Assessment

Potential Construction Noise Impacts

5.13 The construction and operation of the proposed concrete batching plant is scheduled to be carried out from December 2000 to December 2001, including three phases as shown in the following table.

12/2000	01/2001 – 03/2001	04/2001 – 12/2001
Phase 1	Phase 2	Phase 3
Construction of Stage 1 batching plant	Construction of Stage 2 batching plant and operation of Stage 1 batching plant	Operation of Stage 2 batching plant

5.14 A list of powered mechanical equipment (PME) items to be used during the construction and operation of the concrete batching plant, as well as the associated sound power levels (SWLs) are given in the Appendix 5.2. As the conveyor belt will be fully enclosed on all four sides and therefore its contribution to the total sound power level of the concrete batching plant is excluded.

5.15 The unmitigated noise levels for the construction and operation of the concrete batching plant in the three phases at the representative NSRs have been predicted and are presented in Table 5.3. The notional noise source due to the construction of the concrete batching plant and the location of the concrete batching plant are approximately the same. Therefore, same distances are assumed in the assessment of the construction and operation phases noise impact.

Table 5.3 Predicted Noise level due to the operation and construction of Concrete Batching Plant only (Unmitigated)

NSR No.	Approximately Distance to the notional Noise Source of the concrete batching plant(m)	Predicted Noise Level, dB(A)			EIAO-TM Noise Criteria, dB(A)
		Phase 1	Phase 2	Phase 3
SR2	930	60	61	59	75
SR3	813	61	62	60	75
SR4	663	62	64	62	75
SR5	585	64	65	63	75
SR6	565	64	66	63	75
SR7	562	64	66	63	75
SR8	500	65	67	64	75
SR9	613	63	65	62	75
SR10	570	64	66	63	75
SR11	650	63	64	62	75
SR12	763	61	63	61	75
SR13	813	61	62	60	75
SR19	325	69	70	68	75
SR19 a	380	67	69	67	75
SR19 b	398	67	69	66	75
SR21*	600	63	65	63	70 (65)
SR22	695	62	64	61	75
SR23	825	61	62	60	75
SR24*	763	61	63	61	70 (65)
SR25*	850	60	62	60	70 (65)
SR26*	863	60	62	59	70 (65)
SR27	633	63	65	62	75
SR40*	830	60	62	60	70 (65)

Note: * denotes education institution

Sound Pressure Level inside ( ) indicates the noise limit for education institutions during the examination period.

5.16 As indicated in Table 5.3, the noise levels at the NSRs are predicted to be in the range of 59-70dB(A). The predicted noise levels at all the residential and educational NSRs would be below the noise criterion of 75dB(A) for residential dwellings and 70dB(A) for schools during normal periods and 65dB(A) during examination periods.

5.17 In order to assess the possible cumulative effect of the noise from the construction of Northern Access Road and other roads, and the construction/operation of the concrete batching plant, the cumulative noise levels at the representative NSRs have been calculated and are presented in Table 5.4. The cumulative noise levels at the NSRs are predicted to vary between 59 and 76dB(A). The result indicates that though the cumulative noise levels at all the educational NSRs would comply with the noise criterion of 70dB(A), the cumulative noise levels at some of schools still exceed the noise criterion of 65 dB(A) during examination. On the other hand, due to the cumulative effect, the noise levels at a residential NSR (SR19) are predicted to exceed 75dB(A) criterion by 1dB(A) during the duration between January and March of 2001. Hence, appropriate mitigation measures for the construction and operation of batching plant are required to alleviate the noise impacts. The appropriate mitigation measures are recommended in the following sections.

Table 5.4 Cumulative Construction Noise Levels (Unmitigated)

NSR	Dec-00	Jan-01	Feb-01	Mar-01	Apr-01	May-01	Jun-01	Jul-01	Aug-01	Sep-01	Oct-01	Nov-01	Dec-01
SR2	65	63	63	62	61	65	61	59	61	61	61	61	61
SR3	75	74	74	75	72	74	75	68	75	75	74	73	73
SR4	74	73	74	69	72	74	69	66	69	69	69	72	72
SR5	66	68	68	68	66	66	66	66	65	65	65	65	65
SR6	64	66	67	66	66	66	66	66	66	66	66	63	63
SR7	69	71	72	72	72	72	72	72	70	70	70	65	67
SR8	72	74	74	74	74	74	74	75	72	71	71	66	70
SR9	75	75	75	74	74	75	73	70	72	72	72	75	75
SR10	69	71	70	71	70	70	69	69	66	65	66	65	67
SR11	65	66	66	66	65	65	65	65	64	64	64	64	64
SR12	64	65	65	65	64	64	64	64	63	63	63	63	63
SR13	63	64	64	64	63	63	63	63	62	62	62	62	62
SR19	75	76	76	76	75	75	75	75	74	74	74	74	74
SR19A	74	75	75	75	74	74	74	74	73	73	73	73	73
SR19B	74	75	75	75	74	74	74	74	73	73	73	73	73
SR21*	66	67	67	67	66	66	66	66	65	65	65	65	65
SR22	66	67	67	67	65	65	65	65	64	64	64	64	64
SR23	66	66	66	66	65	65	62	62	62	62	62	62	62
SR24*	67	66	66	66	65	65	64	64	64	64	64	64	64
SR25*	62	63	63	63	61	61	63	63	63	63	63	63	63
SR26*	64	64	64	64	63	63	62	62	62	62	62	62	62
SR27	64	66	66	66	64	64	64	64	63	63	63	63	63
SR40*	64	64	64	64	63	63	62	62	61	61	61	61	61

Noted: * denotes educated institutes

Bold means exceedance of the EIAO-TM criteria (75 dB(A) for residential dwellings, 70dB(A) for education institutions during normal periods and 65dB(A) for education institutions during examination period)

Mitigation Measures

5.18 In order to alleviate the noise impacts from the construction and operation of the concrete batching plant, appropriate and practicable mitigation measures have been recommended and are presented in the following sections.

Selecting Quiet Plant and Working Methods

5.19 The most effective way to mitigate noise impact is to reduce noise at source. This involves using quieter equipment plants. With reference to the two documents (R1 and R2), GW-TM and the BS5228: Part 1: 1997 “Noise Control on Construction and open Sites”, some quieter equipment has been selected, including generator, excavator, mobile crane, truck and vibration poker.

5.20 In addition to the above recommended mitigation measures, percentage ‘on-time’ of each PME (the time when the PME is in operation within a 30 minutes time slot) has been taken into account to give a more realistic calculation.

5.21 With the adoption of the recommended mitigation measures and the percentages ‘on –time, the total SWLs for the construction and operation activities of the batching plant are presented in Appendix 5.3. The mitigated noise levels for the Concrete Batching Plant and the cumulative noise levels at the representative NSRs have been calculated and are given in Table 5.5 and 5.6, respectively.

5.22 As indicated in Table 5.6, with the implementation of the recommended mitigation measures, the cumulative construction noise levels at almost all the NSRs (except 24) could be mitigated to be within the EIAO-TM criteria of 75dB(A) for residential dwellings, and 70dB(A) for education institutions during normal periods and 65dB(A) for examination. Therefore, no further mitigation measures are required.

5.23 However, it is noted that 1dB(A) exceedances of the 65dB(A) (noise criterion for schools during examination periods) at SR24 (Lui Ming Choi Secondary School) are predicted in December 2000. On checking with the examination schedule in Lui Ming Choi Secondary School, there is no examination in December. Therefore, the cumulative predicted noise level at SR24 still complies with the 70dB(A) for education institutions during normal periods.

Table 5.5 Predicted Noise level due to the operation and construction of Concrete Batching Plant only (Mitigated)

NSR	Dec-00	Jan-01	Feb-01	Mar-01	Apr-01	May-01	Jun-01	Jul-01	Aug-01	Sep-01	Oct-01	Nov-01	Dec-01
SR2	52	57	57	57	56	56	56	56	56	56	56	56	56
SR3	53	58	58	58	58	58	58	58	58	58	58	58	58
SR4	55	60	60	60	59	59	59	59	59	59	59	59	59
SR5	56	61	61	61	60	60	60	60	60	60	60	60	60
SR6	56	61	61	61	61	61	61	61	61	61	61	61	61
SR7	57	61	61	61	61	61	61	61	61	61	61	61	61
SR8	58	62	62	62	62	62	62	62	62	62	62	62	62
SR9	56	61	61	61	60	60	60	60	60	60	60	60	60
SR10	56	61	61	61	61	61	61	61	61	61	61	61	61
SR11	55	60	60	60	60	60	60	60	60	60	60	60	60
SR12	54	59	59	59	58	58	58	58	58	58	58	58	58
SR13	53	58	58	58	58	58	58	58	58	58	58	58	58
SR19	61	66	66	66	66	66	66	66	66	66	66	66	66
SR19A	60	65	65	65	64	64	64	64	64	64	64	64	64
SR19B	60	64	64	64	64	64	64	64	64	64	64	64	64
SR21*	56	61	61	61	60	60	60	60	60	60	60	60	60
SR22	55	60	60	60	59	59	59	59	59	59	59	59	59
SR23	53	58	58	58	57	57	57	57	57	57	57	57	57
SR24*	54	59	59	59	58	58	58	58	58	58	58	58	58
SR25*	53	58	58	58	57	57	57	57	57	57	57	57	57
SR26*	53	58	58	58	57	57	57	57	57	57	57	57	57
SR27	55	60	60	60	60	60	60	60	60	60	60	60	60
SR40*	53	58	58	58	57	57	57	57	57	57	57	57	57

Noted: * denotes educated institutes

Table 5.6 Cumulative Noise Levels (Mitigated)

NSR	Dec-00		Jan-01	Feb-01	Mar-01	Apr-01	May-01	Jun-01	Jul-01	Aug-01	Sep-01	Oct-01	Nov-01	Dec-01
SR2	64	61		60	59	60	64	59	56	60	60	60	60	60
SR3	74	74		73	75	72	74	75	67	75	75	74	73	73
SR4	73	72		73	68	72	74	68	65	68	68	68	72	72
SR5	64	65		65	65	65	65	65	65	64	64	64	64	64
SR6	57	61		65	62	65	65	65	65	65	65	65	61	61
SR7	68	70		71	71	72	72	72	72	70	70	70	63	66
SR8	72	73		73	74	74	74	74	74	71	71	71	65	69
SR9	74	74		75	74	74	75	72	70	72	72	72	75	73
SR10	67		70	69	70	70	70	69	69	64	63	64	63	66
SR11	62		64	64	64	64	64	64	64	62	62	62	62	62
SR12	61		63	63	63	63	63	63	63	61	61	61	61	61
SR13	60		62	62	62	62	62	62	62	61	61	61	61	61
SR19	74		75	75	75	75	75	75	75	73	73	73	73	73
SR19A	73		74	74	74	74	74	74	74	73	73	72	73	73
SR19B	73		74	74	74	74	74	74	74	73	73	73	73	73
SR21*	64		65	65	65	65	65	65	65	64	64	64	64	64
SR22	64		65	65	65	65	65	64	64	63	63	63	63	63
SR23	65		65	65	65	65	65	61	61	61	61	61	61	61
SR24*	66		65	65	65	65	65	63	63	63	63	63	63	63
SR25*	59		60	60	60	59	59	62	62	62	62	62	62	62
SR26*	63		62	62	62	62	62	61	61	61	61	61	61	61
SR27	60		62	62	62	62	62	62	62	61	61	61	61	61
SR40*	62		62	62	62	62	62	60	60	60	60	60	60	60

Noted: * denotes educated institutes

Monitoring Audit

5.24 The Independent Environmental Consultant should conduct regular monitoring and audit during the construction works.

Conclusions

5.25 The construction of Roads and other Main works, and the construction /operation of the concrete batching plant will be carried out concurrently. An assessment for cumulative construction noise impacts arising from these activities has been conducted. The assessment result shows that the cumulative noise levels at some NSRs (SR19, 21 and 24) would likely exceed the EIAO-TM noise criteria without mitigation measures for the construction/operation of the concrete batching plant.

5.26 In order to alleviate the cumulative noise impacts, appropriate mitigation measures including the use of quiet equipment in both construction and operation stages of the concrete batching plant. With the adoption of the recommended mitigation measures, the predicted noise levels at all the representative NSRs would comply with the EIAO-TM criteria for residential dwellings and for schools during normal and examination periods.