4. Noise Impact Assessment. 37

4.1 Introduction. 37

4.2 Relevant Legislations, Standards & Guidelines. 37

4.3 Baseline Environmental Conditions. 38

4.4 Assessment Area and Noise Sensitive Receivers. 39

4.5 Assessment Methodology. 41

4.6 Noise Impact Assessment 43

4.7 Good Site Practices. 50

4.8 Residual Construction Noise Impacts. 50

4.9 Cumulative Noise Impact 51

4.10 Summary. 51

List of Figures

Figure 4.1	Noise Impact Assessment – Key Plan
Figure 4.2	Location of Representative Noise Sensitive Receivers at Sung Shan New Village
Figure 4.3	Location of Representative Noise Sensitive Receivers at Tai Wo
Figure 4.4	Location of Representative Noise Sensitive Receivers at Lin Fa Tei
Figure 4.5	Location of Representative Noise Sensitive Receivers at Ha Che
Figure 4.6	Photographs of Representative Noise Sensitive Receivers at Sung Shan New Village
Figure 4.7	Photographs of Representative Noise Sensitive Receivers at Tai Wo
Figure 4.8a	Photographs of Representative Noise Sensitive Receivers at Lin Fa Tei (Sheet 1 of 2)
Figure 4.8b	Photographs of Representative Noise Sensitive Receivers at Lin Fa Tei (Sheet 2 of 2)
Figure 4.9	Photographs of Representative Noise Sensitive Receivers at Ha Che

List of Appendices

Appendix 4-1a-1d Locations of Works Areas

Appendix 4-2a Plant Inventory (Unmitigated Scenario)

Appendix 4-2b Predicted Construction Noise Levels (Unmitigated Scenario)

Appendix 4-3a Plant Inventory (Mitigated Scenario)

Appendix 4-3b Predicted Construction Noise Levels (Mitigated Scenario)

Appendix 4-4 Potential Overlapping Works Areas with Other Projectsv

Appendix 4-5 Typical Section Drawing of Temporary/Movable Noise Barrier

4. Noise Impact Assessment

4.1 Introduction

4.1.1. This section presents the assessment on the potential noise impacts that are likely to be generated during the construction phase of the Project. Appropriate mitigation measures have been identified to mitigate the potential noise impacts arising from construction phase of the Project.

4.1.2. The Project will not involve any fixed noisy plant and will not generate noise during the operational phase. It also will only involve channel widening and new drainage conduits and no pumping station will be constructed. As such, operational noise impact has not been considered further.

4.1.3. This assessment has been carried out based on the criteria and guidelines for evaluation and assessment of noise impacts as stated in Annex 5 and 13 of EIAO-TM and has covered the scope outlined in Section 3.4.2 of the EIA Study Brief.

4.2 Relevant Legislations, Standards & Guidelines

4.2.1. The relevant legislation and associated guidance applicable to the present study for the assessment of noise impacts include:

Noise Control Ordinance (NCO) (Cap.400);

Environmental Impact Assessment Ordinance (EIAO) (Cap.499);

Technical Memorandum on Noise from Construction Work other than Percussive Piling (GW-TM).

Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM); and

EIAO Guidance Note – Preparation of Construction Noise Impact Assessment under the Environmental Impact Assessment Ordinance (GN9/2010).

4.2.2. The NCO provides the statutory framework for noise control in Hong Kong. Assessment procedures and standards are set out in the respective TM promulgated under the NCO.

4.2.3. To ensure a better environment, the EIAO-TM promulgated under the EIAO has imposed more stringent criteria. There is no statutory limit on the noise from general construction works during the non-restricted hours (i.e. the hours between 0700 and 1900 any day not being a Sunday or general holiday) under the NCO and the related TMs. Noise impact arising from general construction activities other than percussive piling during the non-restricted hours are assessed against the noise criteria as stipulated in Table 1B of Annex 5 of the EIAO-TM as shown in Table 4‑1.

Table 4‑1 Noise Standards for Daytime Construction Activities

Noise Sensitive Uses	Noise Standards, Leq (30min), dB(A) ^(1), (2)
	0700 to 1900 hours on any day not being a Sunday or general holiday
All domestic premises including temporary housing accommodation	75
Hotels and hostels	75
Educational institutions including kindergartens, nurseries and all others where unaided voice communication is required	70 65 (During examinations)

Notes:

(1) The above noise standards apply to uses which rely on openable windows for ventilations.

(2) The above standards should be viewed as the maximum permissible noise levels assessed at 1m from the external facade.

4.2.4. No percussive piling is anticipated for the Project. Notwithstanding, should percussive piling be required, the requirements in Technical Memorandum on Noise from Percussive Piling (PP-TM) shall be followed.

4.3 Baseline Environmental Conditions

Sung Shan New Village

4.3.1. The proposed works area is located within Sung Shan New Village and Tong Tau Po Tsuen as shown in Figure 2.2. The surrounding land uses comprise village houses, temporary structures, open storage areas, vehicle repairing areas, offices and workshops. A soy sauce factory is located on the northern side of the proposed works area. During the site visit in January 2019, the background noise environment was dominated by the traffic noise from the village access road and Tai Shu Ha Road East and noise from industrial activities.

Tai Wo

4.3.2. The proposed works area is located within Cheung Po and Tai Wo as shown in Figure 2.3. The surrounding land uses comprise village houses, open car parking areas, playground and agricultural lands. MTR Corporation Pat Heung Depot and Kam Ho Road (classified as a “rural road” according to the Annual Average Daily Traffic (AADT) Census 2019) are in close proximity to the proposed drainage improvement works alignment at Cheung Po. During the site visit in January 2019, the major noise sources are contributed by traffic noise from Kam Ho Road and railway noise from MTR Corporation Pat Heung Depot.

Lin Fa Tei

4.3.3. The proposed works area is located at Lin Fa Tei as shown in Figures 2.4A and 2.4B. The land uses in the vicinity of the proposed works area at this village are low rise residential buildings, car parking area, open storage areas and car scrapyard. Kam Sheung Road (classified as a “rural road” according to the AADT Census 2019) runs to the northern portion of the proposed works area. The noise climate of the proposed works area surroundings is contributed by the traffic noise from Kam Sheung Road and Kam Shui South Road and village access roads and noise from industrial activities. During the site visits in April 2019, there were two or more clusters of low rise buildings being constructed next to the proposed drainage improvement works area near the junction of Kam Sheung Road and Kam Shui South Road.

Ha Che

4.3.4. The proposed works area is located within Sheung Che Tsuen, Chuk Hang and A Kung Tin as shown in Figures 2.5A and 2.5B. The major land uses in the vicinity of the proposed works area are low rise residential buildings, temporary structures, open storage areas and workshops. Fan Kam Road (classified as a “rural road” according to the AADT Census 2019) runs crossing the proposed works area. A Fire Services Department Training School is located close to the proposed drainage improvement works area at A Kung Tin. During the site visits in April 2019, the major noise sources are traffic noise from Fan Kam Road and noise from industrial activities.

4.4 Assessment Area and Noise Sensitive Receivers

4.4.1. The assessment area for noise impact assessment covers all areas within 300 m from the proposed drainage improvement works site boundary and is shown in Figure 4.1. Representative noise sensitive receivers (NSRs) within 300m assessment area have been identified according to the criteria set out in Annex 13 of the EIAO-TM. These NSRs are identified based on the review of the latest information from Planning Department (PlanD) and Lands Department (LandsD) as well as the statutory Outline Zoning Plans (OZPs) including OZP No. S/YL-TT/17 (Tai Tong), S/YL-KTS/15 (Kam Tin South), S/YL-SK/9 (Skek Kong) and S/YL-PH/11 (Pat Heung) and information available in the Statutory Planning Portal of Town Planning Board. Site visits were conducted in January and April 2019 to verify the identification of NSRs and update the status of the NSRs following the desktop review. No planned nor committed representative NSRs were identified.

4.4.2. Only the first layer of NSRs located closest to the noise sources have been identified as the representative noise assessment points for assessment as they would be worst affected and would also provide acoustic shielding to the generally low rise village house type receivers at further distance behind. Other NSRs further away from these representative NSRs are expected to be less affected. The representative NSRs selected for the noise assessment are presented in Table 4‑2. The locations of these representative NSRs are shown in Figures 4.2 to 4.5 and the relevant photographs are provided in Figures 4.6 to 4.9.

Table 4‑2 Representative Noise Sensitive Receivers

NSR ID	Description of NSRs	Nature of Use	Approximate Horizontal Distance from the NSR to Proposed Works Area (m)	Approximate ground level of NSRs (mPD)	No. of Storeys
Sung Shan New Village
SSNV1	#88A, Yau Cha Po	Residential	12	12.7	3
SSNV2	Village house next to a nullah in Tong Tai Po Tsuen (near DD118 1720 S.A)	Residential	2	13.3	2
SSNV3	Village house near a soy sauce factory in Sung Shan New Village (near DD118 1712)	Residential	2	12.7	1
SSNV4	#107, Yau Cha Po	Residential	15	19.5	2
SSNV5	#25, Sung Shan New Village	Residential	30	14.4	1
SSNV6	#43, Sung Shan New Village	Residential	19	14.4	1
SSNV7	Temporary structure next to a track in Sung Shan New Village (DD118 Lot. 1767)	Residential	36	15.8	1
Tai Wo
TW1	Temporary structure near footbridge in Cheung Po (DD112 Lot.837 S.A.RP)	Residential	15	15.4	1
TW2	#200, Cheung Po	Residential	36	17.3	3
TW3	Kai Yip Garden, #3H, Tai Wo	Residential	50	20.6	3
TW4	#40B, Tai Wo	Residential	37	21.8	3
Lin Fa Tei
LFT1	#2G, Lin Fa Tei	Residential	6	23.1	3
LFT2	Temporary building next to a nullah in Lin Fa Tei (DD112 Lot. 964)	Residential	3	25.4	1
LFT3	#125, Lin Fa Tei	Residential	<1	19.4	2
LFT4	#156A, Lin Fa Tei	Residential	4	19.2	3
LFT5	#156B, Lin Fa Tei	Residential	4	19.2	3
LFT6	#47, Shui Tsan Tin	Residential	6	17.5	2
LFT7	Village house near the nullah (DD112 699 S.E)	Residential	2	17.5	3
LFT8	Village house near the nullah (DD112 680 S.C)	Residential	1	17.6	3
LFT9	Village house near the nullah (DD112 679 S.C)	Residential	1	18.6	3
LFT10	Moon Wo Grand Houses, #510, Lin Fa Tei	Residential	14	19.5	4
LFT11	#210 Ngau Keng	Residential	4	20.1	3
LFT12	#297, Lin Fa Tei	Residential	3	19.8	3
LFT13	#290, Lin Fa Tei	Residential	2	19.3	3
LFT14	#231C, Lin Fa Tei	Residential	2	20.1	3
Ha Che
HC1	#149, Chuk Hang	Residential	10	20.2	4
HC2	Block 29, Fu Hing Garden, #88 Sheung Che	Residential	6	20.2	3
HC3	Block P, Fu Hing Garden, #88 Sheung Che	Residential	4	21.5	3
HC4	Block N, Fu Hing Garden, #88 Sheung Che	Residential	1	21.8	4
HC5	Block F, Fu Hing Garden, #88 Sheung Che	Residential	1	22.3	4
HC6	#1C, Chuk Hang	Residential	1	23.2	3
HC7	#300, Sheung Che	Residential	3	22.5	3
HC8	The Arbutus House 12, #52, Shui Kan Shek	Residential	4	27.1	3

4.5 Assessment Methodology

4.5.1. The construction noise impact has been assessed based on the following methodology:

· Determine extent of the 300 m assessment area from the proposed Project Site Boundary;

· Identify representative NSRs which would most likely be affected by noise from the proposed construction works;

· Obtain the construction method and works sequence for the construction period from the Engineer;

· Obtain the items of Powered Mechanical Equipment (PME) for each construction activity (including number of each type of plant and utilization rate) from Engineer;

· Determine the Sound Power Levels (SWLs) of plant items according to the information stated in the GW-TM or other recognized sources of reference. Where appropriate;

· Calculate the distance attenuation from notional noise source. Under the GW-TM, the distance attenuation will be determined by the following formula:

· Distance attenuation in dB(A) = 20 Log D + 8 [where D is distance in metre];

· Apply corrections in the calculations such as potential screening effect and acoustic reflection, if any;

· A +3 dB(A) façade correction has been applied to account for the facades effect at each NSR;

· Calculate the unmitigated Predicted Noise Levels at the identified NSRs;

· Consider accumulative noise impact from concurrent projects within 300m of the NSRs, if any;

· If necessary, selection of project-specific quiet PME and other types of mitigation measures (e.g. temporary/ movable noise barrier, enclosure, etc.) to address the predicted noise exceedance; and calculate the mitigated noise impact; and

· Calculate the mitigated predicted noise levels at the identified NSRs and compare with the noise standards to determine acceptability and the need for further mitigation/ environmental monitoring and audit.

4.5.2. As a conservative approach for assessing the worst-case construction noise impacts, it was assumed that all the proposed PMEs for each work stage are operating concurrently. Various combination of works located close to the NSRs have been considered and the maximum SWLs generated from the Project works was calculated and applied in the calculation of cumulative worst-case construction noise level at the NSRs.

4.5.3. For each proposed work areas (Sung Shan New Village, Tai Wo, Lin Fa Tei and Ha Che), the drainage improvement works will be conducted by sections. The length of each section will be approximately 30 m in Sung Shan New Village and Ha Che, 15m in Tai Wo and 25m in Lin Fa Tei, respectively.

4.5.4. For conducting the early stage drainage improvement work i.e. excavation, it is expected that there will only be one group of workers working beginning at the downstream. After this early stage work, a maximum of two groups of workers will carry out concurrent activities at two adjoining sections at any one time due to a limited number of Powered Mechanical equipment (PMEs) and narrow working space. Therefore, the assessment has adopted the maximum total SWLs of two works section areas (i.e. the nearest two adjoining construction works areas to the representative NSRs and/or two adjoining construction works areas with conducting specific works to affect the nearest representative NSRs) under construction concurrently. The construction works that are expected to affect works areas to the representative NSRs are shown in Table 4‑3 and the locations of the respective works areas are shown in Appendix 4-1a to 4-1d.

Table 4‑3 Works Sites Affecting the Representative NSRs

NSR ID	Description of NSRs	Nature of Use	Works Sites (Sections) That would affect the NSR during Construction Phase	Locations of Works Sites (Sections)
Sung Shan New Village
SSNV1	#88A, Yau Cha Po	Residential	S102 & S103	Refer to Appendix 4-1a
SSNV2	Village house next to a nullah in Tong Tai Po Tsuen (near DD118 1720 S.A)	Residential	S104 & S105
SSNV3	Village house near a soy sauce factory in Sung Shan New Village (near DD118 1712)	Residential	S112 & S113
SSNV4	#107, Yau Cha Po	Residential	S113 & S114
SSNV5	#25, Sung Shan New Village	Residential	S115 & S116 S116 & S117
SSNV6	#43, Sung Shan New Village	Residential	S118 & S119 S119 & S120
SSNV7	Temporary structure next to a track in Sung Shan New Village (DD118 Lot. 1767)	Residential	S119 & S120
Tai Wo
TW1	Temporary structure near footbridge in Cheung Po (DD113 Lot.1542)	Residential	S201 & S202	Refer to Appendix 4-1b
TW2	#200, Cheung Po	Residential	S205 & S206 S206 & S207
TW3	Kai Yip Garden, #3H, Tai Wo	Residential	S217 & S218
TW4	#40B, Tai Wo	Residential	S217 & S218
Lin Fa Tei
LFT1	#2G, Lin Fa Tei	Residential	S332 & S333	Refer to Appendix 4-1c
LFT2	Temporary building next to a nullah in Lin Fa Tei (DD112 Lot. 964)	Residential	S327 & S328
LFT3	#125, Lin Fa Tei	Residential	S316 & S317
LFT4	#156A, Lin Fa Tei	Residential	S311 & S312 S312 & S313
LFT5	#156B, Lin Fa Tei	Residential	S311 & S312
LFT6	#47, Shui Tsan Tin	Residential	S308 & S309 S309 & S310
LFT7	Village house near the nullah (DD112 699 S.E)	Residential	S304 & S305
LFT8	Village house near the nullah (DD112 680 S.C)	Residential	S301 & S302
LFT9	Village house near the nullah (DD112 679 S.C)	Residential	S301 & S302
LFT10	Moon Wo Grand Houses, #510, Lin Fa Tei	Residential	S341 & S342 S342 & S343
LFT11	#210 Ngau Keng	Residential	S346 & S347 S347 & S348
LFT12	#297, Lin Fa Tei	Residential	S350 & S351 S351 & S352
LFT13	#290, Lin Fa Tei	Residential	S352 & S353 S353 & S354
LFT14	#231C, Lin Fa Tei	Residential	S353 & S354
Ha Che
HC1	#149, Chuk Hang	Residential	S401 & S402	Refer to Appendix 4-1d
HC2	Block 29, Fu Hing Garden, #88 Sheung Che	Residential	S401 & S402
HC3	Block P, Fu Hing Garden, #88 Sheung Che	Residential	S402 & S403
HC4	Block N, Fu Hing Garden, #88 Sheung Che	Residential	S404 & S405
HC5	Block F, Fu Hing Garden, #88 Sheung Che	Residential	S405 & S406
HC6	#1C, Chuk Hang	Residential	S409 & S410
HC7	#300, Sheung Che	Residential	S409 & S410 S410 & S411
HC8	The Arbutus House 12, #52, Shui Kan Shek	Residential	S423 & S424

4.6 Noise Impact Assessment

Identification of Potential Noise Impacts

4.6.1. The potential source of noise impact during construction phase of the Project would be the use of PMEs for various construction activities. There are four major construction works types to be carried out which are relevant to the construction noise assessment as follows:

Works Type 1 – Widening of the existing drainage channel at Sung Shan New Village;

Works Type 2 – Construction of drainage channel at Tai Wo;

Works Type 3 – Widening of the existing drainage channel and construction of a new drainage pipe at Lin Fa Tei; and

Works Type 4 – Widening of the existing drainage channel and construction of a new drainage pipe at Ha Che.

4.6.2. All the works types will be conducted in stages and implemented concurrently. With consideration that the separation distance between drainage improvement works at each village are more than 300m, cumulative noise impact is not expected between each work type. Estimated durations of the construction work are provided in Table 4-4. The proposed works will be conducted during non-restricted hours only, i.e. between 07:00 and 19:00 hours on any day except Sunday and general holiday.

Table 4‑4 Tentative Construction Activities Schedule

Works Stage	Construction Activities	Estimated Duration per Section
Works Type 1 – Widening of the existing drainage channel at Sung Shan New Village ^(1) (2)
Stage 1	Excavation	5 weeks
Stage 2	Formwork and Reinforcement
Works Type 2- Construction of drainage channel at Tai Wo ^(1) (2)
Stage 1	Excavation	4 weeks
Stage 2	Formwork and Reinforcement
Works Type 3 – Widening of the existing drainage channel and construction of new drainage pipes at Lin Fa Tei ^(1) (2)
Stage 1	Excavation	4 weeks
Stage 2	Formwork and Reinforcement
Works Type 4 – Widening of the existing drainage channel and construction of new drainage pipes at Ha Che ^(1) (2)
Stage 1	Excavation	3 weeks
Stage 2	Formwork and Reinforcement

Notes:
(1) Only one set of PME of stage 1 and stage 2 will be undertaken concurrently for each works type; and

(2) Note that works programme is subject to variables such as weather, conflict with utilities etc. and is variable upon these conditions

4.6.3. An inventory of project specific PMEs required for the proposed drainage improvement works is detailed in Appendix 4-2a. A summary of the predicted maximum SWLs of the different works types are provided in Table 4‑5. Whilst it is possible that the future appointed Contractor may adopt a different plant inventory, this assessment has been undertaken based on the plant inventory detailed in Appendix 4-2a to allow early identification of any potential noise issues and to ensure there are practicable and sufficient noise mitigation measures that can be implemented to alleviate adverse noise impacts. The Contractor will be required to provide and implement sufficient direct noise mitigation measures based on the recommendation in this assessment to achieve acceptable noise levels on the nearby NSRs. The Contractor would also use the plant with SWL equivalent to or lower than that in the plant inventory for carrying out the proposed construction activities.

Table 4‑5 Summary of Maximum SWLs of the Different Works Types

Works Stage	Construction Activities	SWL, dB(A)
Works Type 1 – Widening of the existing drainage channel at Sung Shan New Village
Stage 1	Excavation	115
Stage 2	Formwork and Reinforcement	110
Works Type 2- Construction of drainage channel at Tai Wo
Stage 1	Excavation	115
Stage 2	Formwork and Reinforcement	110
Works Type 3 – Widening of the existing drainage channel and construction of new drainage pipes at Lin Fa Tei
Stage 1	Excavation	115
Stage 2	Formwork and Reinforcement	110
Works Type 4 – Widening of the existing drainage channel and construction of new drainage pipes at Ha Che
Stage 1	Excavation	115
Stage 2	Formwork and Reinforcement	110

Note:

Only one set of PME of stage 1 and stage 2 will be undertaken concurrently for each works type;

Detailed construction plant inventory is shown in Appendix 4-2a.

Prediction of Construction Noise Impacts – Unmitigated Scenario

4.6.4. The predicted noise levels at the representative NSRs due to the proposed drainage improvement works at Sung Shan New Village, Tai Wo, Lin Fa Tei and Ha Che are summarized in Table 4‑6. Detailed calculations are provided in Appendix 4-2b.

Table 4‑6 Predicted Noise Levels at the Representative NSRs Affected by the Proposed Project Works – Unmitigated Scenario

NSR ID	Description of NSRs	No. of Storeys	Predicted Maximum Noise Level, dB(A)	EIAO-TM Noise Standard, dB(A).	Noise Exceedance, dB(A)
Sung Shan New Village
SSNV1	#88A, Yau Cha Po	3	87	75	12
SSNV2	Village house next to a nullah in Tong Tai Po Tsuen (near DD118 1720 S.A)	2	91	75	16
SSNV3	Village house near a soy sauce factory in Sung Shan New Village (near DD118 1712)	1	91	75	16
SSNV4	#107, Yau Cha Po	1	85	75	10
SSNV5	#25, Sung Shan New Village	1	81	75	6
SSNV6	#43, Sung Shan New Village	1	84	75	9
SSNV7	Temporary structure next to a track in Sung Shan New Village (DD118 Lot. 1767)	1	77	75	2
Tai Wo
TW1	Temporary structure near footbridge in Cheung Po (DD112 Lot.837 S.A.RP)	1	84	75	9
TW2	#200, Cheung Po	3	81	75	6
TW3	Kai Yip Garden, #3H, Tai Wo	3	78	75	3
TW4	#40B, Tai Wo	3	79	75	4
Lin Fa Tei
LFT1	#2G, Lin Fa Tei	3	91	75	16
LFT2	Temporary building next to a nullah in Lin Fa Tei (DD112 Lot. 964)	1	93	75	18
LFT3	#125, Lin Fa Tei	2	96	75	21
LFT4	#156A, Lin Fa Tei	3	95	75	20
LFT5	#156B, Lin Fa Tei	3	92	75	17
LFT6	#47, Shui Tsan Tin	2	92	75	17
LFT7	Village house near the nullah (DD112 699 S.E)	3	92	75	17
LFT8	Village house near the nullah (DD112 680 S.C)	3	93	75	18
LFT9	Village house near the nullah (DD112 679 S.C)	3	95	75	20
LFT10	Moon Wo Grand Houses, #510, Lin Fa Tei	4	87	75	12
LFT11	#210 Ngau Keng	3	94	75	19
LFT12	#297, Lin Fa Tei	3	93	75	18
LFT13	#290, Lin Fa Tei	3	94	75	19
LFT14	#231C, Lin Fa Tei	3	91	75	16
Ha Che
HC1	#149, Chuk Hang	4	88	75	13
HC2	Block 29, Fu Hing Garden, #88 Sheung Che	3	92	75	17
HC3	Block P, Fu Hing Garden, #88 Sheung Che	3	91	75	16
HC4	Block N, Fu Hing Garden, #88 Sheung Che	4	93	75	18
HC5	Block F, Fu Hing Garden, #88 Sheung Che	4	94	75	19
HC6	#1C, Chuk Hang	4	92	75	17
HC7	#300, Sheung Che	3	91	75	16
HC8	The Arbutus House 12, #52, Shui Kan Shek	3	92	75	17

Notes:

Underlined bold value indicates an exceedance of the 75dB(A) noise criteria.

4.6.5. The predicted noise levels at the representative NSRs range from 77 dB(A) to 96 dB(A). As shown in Table 4‑6, the maximum level of exceedance predicted would be about 21 dB(A). Mitigation measures would be considered necessary in order to reduce the construction noise impact.

Prediction of Construction Noise Impacts – Mitigated Scenario

4.6.6. To mitigate the construction noise impacts on the affected NSRs during the construction phase, quiet PMEs and smaller sized of PMEs have been proposed as practicable.

4.6.7. The use of quiet PMEs associated with the construction works is made reference to the PME listed in the Quality Powered Mechanical Equipment (QPME), “Sound Power Levels of Other Commonly Used PME” listed in EPD website. It is generally known that particular models of construction equipment are quieter than standard types given in GW-TM. It also should be noted that various type of quiet plant can be available in the market. The SWLs for quiet PMEs adopted for assessment are detailed in Table 4‑7.

Table 4‑7 Recommended PMEs and the SWLs

Description of PME	QPME ID Code	Model No.	SWL, dB(A)
Excavator, wheeled/tracked	EPD-07033 [1]	YANMAR Model: VIO17 Serial No. 0K864	91
Generator	EPD-06600 [1]	DENYO Model: DCA-60LSIE Serial No. 3924606	90
Crane, mobile	EPD-06243 [1]	Kobelco Model: CK90UR-3 Serial No. YA04-01076	92

Notes:

[1] Quality Powered Mechanical Equipment (QPME) ID Code by EPD (https://www.epd.gov.hk/cgi-bin/npg/qpme/search_gen.pl)

4.6.8. Asides from QPMEs, additional noise mitigation measures in terms of temporary noise barriers are proposed to shield construction plants from NSRs. According to EIAO Guidance Note No. 9/2010, with provision of noise barriers, a 5dB(A) noise reduction for movable plant, 10dB(A) for stationary plant and 15dB(a) for enclosed ones are assumed. With reference to ”A Practical Guide for the Reduction of Noise from Construction Works”, temporary noise barrier and enclosure material’s surface mass in excess of 7 kg/m2 and have no openings or gaps is recommended. The Contractor should be responsible for the design of temporary/ movable noise barriers with consideration of the size of PME and the requirements of intercepting the line of sight between the noise sensitive receivers and PME. Typical section drawing of the temporary/movable noise barrier is provided in Appendix 4-5. Table 4‑8 summarizes the assumed noise reduction achieved by the temporary noise barrier/enclosure for certain PMEs.

Table 4‑8 Noise Mitigation Measures for Certain PME

Description of PME	Proposed Mitigation Measures	Assumed Noise Reduction, dB(A)	References
Excavator, wheeled/tracked	Movable noise barrier	-5	[1]
Dump Truck (5.5 tonne < Gross vehicle weight <= 38 tonne)	Fixed Temporary noise barrier	-5	[1]
Lorry (5.5 tonne < Gross vehicle weight <= 38 tonne)	Fixed Temporary noise barrier	-5	[1]
Bar bender and cutter (electric)	Movable noise barrier	-10	[1]
Jig-saw, hand-held, wood (electric)	Movable noise barrier	-10	[1], [2]
Generator	Movable noise barrier	-10	[1]
Crane, mobile	Movable noise barrier and Fixed temporary boundary noise barrier	-5	[1]

Notes:

[1] With reference to the approved EIA report (Residential cum Passive Recreational Development within REC Zone and R (C) Zone at Various Lots in DD 104, Yuen Long. N.T.(AEIAR-182/2014)), the proposed mitigation measures have been recommended to reduce the noise impacts from specific PMEs.

[2] Jig-saw, hand-held, wood (electric) has been proposed to replace the use of Saw, circular, wood.

4.6.9. With adoption of quiet PMEs and temporary/movable barrier, the maximum predicted noise levels at the representative NSRs due to the proposed drainage improvement works are summarized in Table 4‑9. Detailed calculations are provided in Appendix 4-3a and Appendix 4-3b.

Table 4‑9 Predicted Noise Levels at the Representative NSRs Affected by the Proposed Project Works – Mitigated Scenario

NSR ID	Description of NSRs	No. of Storeys	Predicted Maximum Noise Level, dB(A)	EIAO-TM Noise Standard, dB(A).	Noise Exceedance, dB(A)
Sung Shan New Village
SSNV1	#88A, Yau Cha Po	3	66	75	-
SSNV2	Village house next to a nullah in Tong Tai Po Tsuen (near DD118 1720 S.A)	2	70	75	-
SSNV3	Village house near a soybean sauce factory in Sung Shan New Village (near DD118 1712)	1	70	75	-
SSNV4	#107, Yau Cha Po	1	65	75	-
SSNV5	#25, Sung Shan New Village	1	60	75	-
SSNV6	#43, Sung Shan New Village	1	63	75	-
SSNV7	Temporary structure next to a track in Sung Shan New Village (DD118 Lot. 1767)	1	56	75	-
Tai Wo
TW1	Temporary structure near footbridge in Cheung Po (DD112 Lot.837 S.A.RP)	1	63	75	-
TW2	#200, Cheung Po	3	60	75	-
TW3	Kai Yip Garden, #3H, Tai Wo	3	57	75	-
TW4	#40B, Tai Wo	3	58	75	-
Lin Fa Tei
LFT1	#2G, Lin Fa Tei	3	70	75	-
LFT2	Temporary building next to a nullah in Lin Fa Tei (DD112 Lot. 964)	1	72	75	-
LFT3	#125, Lin Fa Tei	2	75	75	-
LFT4	#156A, Lin Fa Tei	3	74	75	-
LFT5	#156B, Lin Fa Tei	3	71	75	-
LFT6	#47, Shui Tsan Tin	2	71	75	-
LFT7	Village house near the nullah (DD112 699 S.E)	3	71	75	-
LFT8	Village house near the nullah (DD112 680 S.C)	3	72	75	-
LFT9	Village house near the nullah (DD112 679 S.C)	3	74	75	-
LFT10	Moon Wo Grand Houses, #510, Lin Fa Tei	4	66	75	-
LFT11	#210 Ngau Keng	3	73	75	-
LFT12	#297, Lin Fa Tei	3	72	75	-
LFT13	#290, Lin Fa Tei	3	73	75	-
LFT14	#231C, Lin Fa Tei	3	70	75	-
Ha Che
HC1	#149, Chuk Hang	4	67	75	-
HC2	Block 29, Fu Hing Garden, #88 Sheung Che	3	71	75	-
HC3	Block P, Fu Hing Garden, #88 Sheung Che	3	70	75	-
HC4	Block N, Fu Hing Garden, #88 Sheung Che	4	72	75	-
HC5	Block F, Fu Hing Garden, #88 Sheung Che	4	73	75	-
HC6	#1C, Chuk Hang	4	71	75	-
HC7	#300, Sheung Che	3	70	75	-
HC8	The Arbutus House 12, #52, Shui Kan Shek	3	71	75	-

4.6.10. With adoption of quiet PMEs and temporary / movable barrier stated above, the predicted construction noise levels at the representative NSRs range 56 dB(A) to 75 dB(A). No construction noise exceedance has been predicted. All predicted construction noise levels at the representative NSRs will fully comply with the relevant noise standard.

4.6.11. The proposed temporary noise barrier will only be in place when the associated PME is in use on the construction work area and this is anticipated to only be for short duration of time. Therefore, there are no side effect predicted associated with the use of the proposed mitigation measure.

4.7 Good Site Practices

4.7.1. Apart from the proposed mitigation measures, good site practices as listed below are recommended to alleviate the noise impacts on the identified NSRs.

· The Contractor shall adopt the Code of Practice on Good Management Practice to Prevent Violation of the NCO (Cap. 400) (for Construction Industry) published by the EPD;

· The Contractor shall observe and comply with the statutory and non-statutory requirements and guidelines;

· Before commencing any work, the Contractor shall submit to the Environmental Review for approval the method of working, equipment and noise mitigation measures intended to be used at the site;

· The Contractor shall devise and execute working methods to minimise the noise impact on the identified surrounding sensitive uses, and provide experienced personnel with suitable training to ensure that those methods are implemented;

· Noisy equipment and noisy activities should be located as far away from the NSRs as is practical;

· Machines and plant (such as dump truck, vibratory compactor, lorry, cranes) that may be intermitted use should be shut down between work periods or should be throttled down to a minimum. Additionally, the combined use of noisy equipment/machines should be avoided, when possible;

· Only well-maintained plant should be operated on-site and plants should be serviced regularly during the construction programme;

· Silencers, mufflers or acoustic treatment mats on construction equipment should be utilised and properly maintained during the construction duration;

· Plants known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from the nearby NSRs; and

· Material stockpiles and other structures should be effectively utilised as noise barriers, where practicable.

4.7.2. The Contractor shall, from time to time, be aware of the noise impacts on the surrounding NSRs through adequate noise monitoring during the works so that adjustments can be made to the number of plants used for any construction activity and the corresponding plant positioning. These requirements shall be incorporated into the Project works contract.

4.8 Residual Construction Noise Impacts

4.8.1. No exceedance of the construction noise criteria has been predicted at the NSRs with implementation of noise mitigation measures as described in Sections 4.6 and 4.7.

4.8.2. With adopting quiet PMEs, temporary noise barriers and implementing good site practices, adverse residual noise impacts are not anticipated.

4.9 Cumulative Noise Impact

4.9.1. As mentioned in Section 2, the construction of drainage improvement works is scheduled from Year 2022 to Year 2025. One project has been identified within proximity of the subject works site. The potential cumulative construction noise impacts are discussed below.

Table 4‑10 Identified Potential Interface Projects within Proximity of the Project

Project	Name of Project	Remarks
No.1	Agreement No. CE 61/2012 (HY) - Improvement to Fan Kam Road – Investigation (2021 to 2025)	The project is still at investigation stage, the exact schedule of works is uncertain and subject to the findings on detail design stage. The project may overlap with the construction of this Project. The potential overlapping area identified in Ha Che Section was shown in Appendix 4-4.

Project 1: Agreement No. CE 61/2012(HY) – Improvement to Fan Kam Road – Investigation

4.9.2. Under Agreement No. CE 61/2012 (HY), a road improvement work is proposed to be constructed along Fan Kam Road and the certain sections will be within the 300m assessment area of the Project. Based on information from the project consultant, the project is still undergoing the investigation stage. The tentative schedule of construction works will be from 2021 to 2025. Since the project is still at investigation stage, the exact schedule of works is uncertain and subject to the findings on detail design stage. With reference to Agreement No. CE 61/2012 (HY), the alignment of the road improvement has potentially interfaced with the proposed drainage improvement works (nearest works under Ha Che section) in the same section for 1 months. The Contractor is recommended to coordinate and liaise with the detail design consultant and/or contractor of the Fan Kam Road improvement project. Construction works schedule should be arranged in order to minimize concurrent works at interface. With this arrangement in place and implementation of mitigation measure, adverse cumulative noise impact due to the improvement works on Fan Kam Road and the drainage improvement works can be avoided.

4.10 Summary

4.10.1. The potential noise impacts due to the proposed drainage improvement works at Sung Shan New Village, Tai Wo, Lin Fa Tei and Ha Che have been evaluated. Whilst the Contractor may prefer to use different construction methods, types and numbers of PMEs, the assumed tentative construction schedule and plant inventory are representative and provide a conservative noise assessment of reference value.

4.10.2. With adopting the quiet PMEs, temporary noise barrier and good site practices as stipulated in the Code of Practice on Good Management Practice to Prevent Violation of the NCO (Cap. 400) (for Construction Industry) to minimize the construction noise impacts, construction noise levels at the representative NSRs will fully comply with the relevant noise criteria.