Consultancy Agreement No. NEX/2301 South Island Line (East) Environmental Impact Assessment 3. Noise Impact 3.1 Introduction This section has evaluated and assessed the potential noise impact likely to arise from the proposed Project during both the construction and operation phases. The noise impact from the proposed Project can be divided into airborne and ground-borne during the construction and operation phases. The assessment has been based on the criteria and guidelines for evaluation and assessing noise impact as stated in Annexes 5 and 13 of the EIAO-TM and NCO and covered the scope outlined in Clause 3.4.1 of the EIA Study Brief. 3.2 Environmental Legislation, Standards and Guidelines 3.2.1 Construction Phase 3.2.1.1 General Construction Activities during Non-Restricted Hours Noise impacts arising from general construction activities other than percussive piling during the daytime period (07:00-19:00 hours of any day not being a Sunday or general holiday) shall be assessed against the noise standards tabulated in Table 3.1 below. Table 3.1: Noise Standards for Daytime Construction Activities 0700 to 1900 hours on any day not being a Sunday or general Noise Sensitive Uses holiday, Leq (30 min), dB(A) All domestic premises including temporary housing accommodation 75 Hotels and hostel Educational institutions including kindergarten, 70 nurseries and all others where unaided voice communication is required 65 during examination Source: EIAO-TM, Annex 5, Table 1B - Noise Standards for Daytime construction Activities Note: The above noise standards apply to uses, which rely on opened windows for ventilation. The noise levels shall be assessed at 1m from the external façade. The above standards are for assessment purposes only and shall be met as far as practicable. All practicable mitigation measures shall be exhausted and the residual impacts are minimised. 3.2.1.2 General Construction Activities during Restricted Hours Noise impacts arising from general construction activities (excluding percussive piling) conducted during the restricted hours (19:00-07:00 hours on any day and anytime on Sunday or general holiday) and percussive piling during anytime are governed by the Noise Control Ordinance (NCO). For carrying out of any general construction activities involving the use of any Powered Mechanical Equipment (PME) within restricted hours, a Construction Noise Permit (CNP) is required from the Authority under the NCO. The noise criteria and the assessment procedures for issuing a CNP are specified in Technical Memorandum on Noise from Construction Work Other Than Percussive Piling (GW-TM) under the NCO. The use of Specified PME (SPME) and/or the carrying out of Prescribed Construction Work (PCW) within a 248137/ENL/ENL/51/F P:\Hong Kong\INF\Projects2\248137 SIL(E) EIA\Deliverables\Final EIA Vol I\3rd\Rev F_Sec 3.doc 3-1 Consultancy Agreement No. NEX/2301 South Island Line (East) Environmental Impact Assessment Designated Area (DA) under the NCO during the restricted hours are also prohibited without a CNP. The relevant technical details in Technical Memorandum on Noise from Construction Work in Designated Areas (DA-TM) under NCO can be referred. Designated areas, in which the control of SPME and PCW shall apply, are established through the Noise Control (Construction Work Designated Areas) Notice made under Section 8A(1) of the NCO. According to the Designated Area defined under the NCO (effective from 1 January 2009), all the works area of this project will fall within these areas. As such, the application for CNP for any general construction activities involving the use of any PME shall refer to the GW-TM only. However, the Contractor has the responsibility to check the latest status and coverage of the Designated Areas at time of construction of the project. According to the construction programme, most of the proposed construction works will be carried out during non-restricted hours. It is also considered necessary to maintain twenty-four hour working inside the tunnel to achieve the required rate of progress due to uncertain geological conditions and fault zones and, the planned construction method necessitates twenty-four hour working to ensure an efficient work cycle. However, those works would be carried out only inside tunnels and at locations away from NSRs, especially at LET and SOH, thus, the potential noise impact to NSRs would be minimal. In case the proponent needs to evaluate whether these construction works during restricted hours are feasible in the context of programming construction works, reference should be made to the relevant technical memoranda issued under the NCO. Regardless of the results of construction noise impact assessment for restricted hours, the Noise Control Authority will process Construction Noise Permit (CNP) application, if necessary, based on the NCO, the relevant technical memoranda issued under the NCO, and the contemporary condition/situations of adjoining land uses and any previous complaints against construction activities at the site before making his decision in granting a CNP. 3.2.1.3 Ground-borne Noise Noise arising from general construction works during normal working hours is governed by the EIAO-TM under the EIAO as shown in Table 3.1. The Technical Memorandum for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites (IND-TM) under the NCO stipulates that noise transmitted primarily through the structural elements of building, or buildings, shall be 10 dB(A) less than the relevant Acceptable Noise Level (ANLs). Based on the same principle for the ground-borne noise criteria (i.e. ANL-10 dB(A) under the IND-TM), the ground-borne construction noise levels inside domestic premises and schools shall be limited to 65 dB(A) and 60 dB(A) respectively when compared to the EIAO-TM. For construction works conducted on general holidays, Sundays and weekdays during evening (1900-2300 hrs) and night time (2300-0700 hrs) the following day, the ground-borne construction noise level shall be limited to 10 dB(A) below the respective ANLs for the Area Sensitivity Rating appropriate to those NSRs affected by the Project. A summary of these criteria is given in Table 3.2 below: 248137/ENL/ENL/51/F P:\Hong Kong\INF\Projects2\248137 SIL(E) EIA\Deliverables\Final EIA Vol I\3rd\Rev F_Sec 3.doc 3-2 Consultancy Agreement No. NEX/2301 South Island Line (East) Environmental Impact Assessment Table 3.2: Ground-borne Noise Criteria (L eq 30min , dB(A)) Ground-borne Noise Criteria (1) , dB(A) Daytime (0700-1900) Daytime (0700-1900) (2) during general holidays NSR type Night-time (2300 – except general holidays and Sundays and all 0700 hrs) and Sunday days during Evening (1900-2300 hrs) All domestic premises including temporary housing accommodation 65 50/55/60 (3,4) 35/40/45 (3,4) Hotels and hostel Educational institutions including kindergarten, nurseries and all 60 N/A (5) N/A (5) others where unaided voice 55 (for during examination) communication is required Notes: (1) Noise descriptor for daytime noise except general holidays and Sunday and other periods are Leq (30min) and Leq (5min) respectively. Measurement shall be carried out at an internal location representative of normal occupancy of the building. For residential building, measurement shall be conducted in the bedroom of the apartment. (2) The standards are for assessment purposes only and shall be met as far as practicable. All practicable mitigation measures shall be exhausted and the residual impacts are minimised. (3) Based on the Basic Noise Level for NSRs with Area Sensitivity Ratings of A, B, and C detailed in the Technical Memorandum on Noise From Construction Work Other Than Percussive Piling. (4) Construction Noise Permit is required for works during this period. (5) No sensitive use in Education institutions during evening and night-time period is assumed except those specified. 3.2.1.4 Blasting There are no statutory procedures and criteria under the NCO and EIAO for assessing the airborne noise impacts of blasting, hence the airborne noise impact generated by this activity is beyond the scope of the EIA. However, the administrative and procedural control of all blasting operations in Hong Kong is vested in the Mines Division of the Civil Engineering and Development Department (CEDD). The Dangerous Goods (General) Regulations, Chapter 295 also stipulates that no person shall carry out blasting unless he/she possesses a valid mine blasting certificate to be issued by the Mines Division of CEDD. The Superintendent of Mines will review the application on a case-by case basis before issuing the Mine Blasting Certificate. 3.2.2 Operation Phase 3.2.2.1 Area Sensitivity Rating (ASR) For the operational railway noise (airborne, structure re-radiated, and ground-borne) and fixed plant noise assessments, the ANLs for the NSRs are determined based on the ASR. ASR is defined in the IND-TM. The ASR depends on the type of area and the degree of impact that Influencing Factors (IFs) have on the NSRs and is determined from Table 3.3 below. Industrial area, major road or the area within the boundary of Hong Kong International Airport shall be considered to be an IF. 248137/ENL/ENL/51/F P:\Hong Kong\INF\Projects2\248137 SIL(E) EIA\Deliverables\Final EIA Vol I\3rd\Rev F_Sec 3.doc 3-3 Consultancy Agreement No. NEX/2301 South Island Line (East) Environmental Impact Assessment Table 3.3: Area Sensitivity Rating Degree to which NSR is affected by IF Type of Area Containing NSR Not Affected Indirectly Affected Directly Affected (i) Rural area, including country parks or village A B B type developments (ii) Low density residential area consisting of low- A B C rise or isolated high-rise developments (iii) Urban area B C C (iv) Area other than those above B B C 3.2.2.2 Airborne Railway Noise In accordance with Annex 5 of the EIAO-TM, noise from rail operation shall be assessed in accordance with the requirements of stipulated in NCO.