Environmental Impact Assessment Ordinance

Technical Memorandum

Annex 13

ANNEX 13 : GUIDELINES FOR NOISE ASSESSMENT

1. General

1.1 The Annex describes the commonly adopted approaches and methodologies for assessment of noise impacts arising from designated projects. The methodologies may vary from case to case, depending on the nature of noise issues and the latest development in methods and techniques.

2. Potential Noise Sources

2.1 The potential noise sources could be, but not limited to, the following:

  1. aircraft noise
  2. helicopter noise
  3. road traffic noise
  4. rail noise
  5. fixed noise sources (including, but not limited to, general industrial noise sources, concrete batching plants, pump houses, gas pressure reduction plants, rock crushing plants, quarries, railway depots/marshalling yards, airport facilities, wholesale markets, bus depots/termini, open car/lorry parks, vehicle pounding areas, refuse handling areas, abattoirs, container terminals, sand depots, public cargo working areas, multi-purpose terminals, fire stations, ambulance depots, tram depots)
  6. construction noise

3. Noise Sensitive Receivers

3.1 The potential noise sensitive receivers, including existing, committed and planned, could be, but not limited to, the following:

  • all domestic premises
  • temporary housing accommodation
  • hostels
  • convalescent homes
  • homes for the aged
  • educational institutions (including kindergarten and nurseries) .
  • places of public worship
  • courts of law
  • hospitals
  • medical clinics, and
  • any other premises or places that are considered by the Director to have similar sensitivity to noise as the above

4. Noise Tolerant Uses

4.1 The potential noise tolerant uses could be, but not limited to, the following:

  1. multi-storey carparks
  2. multi-storey markets
  3. warehouses
  4. community uses (e.g. sports complexes, community centres)
  5. commercial centres/premises, or
  6. other premises (which do not rely on opened windows for ventilation)

5. Assessment Methodology

Road Traffic Noise

5.1 The assessment methodology shall be agreed with the Director prior to the commencement of assessment. Predictions shall normally be based on the design traffic conditions or the maximum traffic projections within 15 years upon operation of the roadworks or occupation of the noise sensitive receivers or uses, whichever appropriate, and shall take into consideration future (both committed and planned) as well as existing roadworks and land uses.

Fixed Noise Sources

5.2 The EIA study shall identify the potential sources and implications for mitigation measures at operation phase. The applicant shall, unless otherwise agreed by the Director, qualitatively demonstrate no adverse fixed noise impact in association with the project in the EIA study. During the pre-tender stage, if any, and before commencement of the project, the applicant shall submit the quantitative fixed noise sources impact assessment for approval, unless otherwise agreed by the Director. The assessment methodology shall be agreed with the Director prior to the commencement of assessment. For assessment point and correction of tonality, impulsiveness and intermittency, reference shall be made to the Technical Memorandum for the Assessment of Noise from places other than Domestic Premises, Public Places or Construction Sites, issued under the Noise Control Ordinance.

Construction Noise

5.3 The applicant shall, unless otherwise agreed by the Director, qualitatively demonstrate no adverse construction noise impact would be associated with the project in the EIA study by adopting quieter construction method and equipment. During the pre-tender stage, if any, and before commencement of the project, the applicant shall submit the quantitative construction noise impact assessment with the project implementation details and proposed noise mitigation measures for approval, unless otherwise agreed by the Director. The assessment methodology shall be agreed with the Director prior to the commencement of assessment.

5.4 In case the proponent or consultant would like to assess whether a Construction Noise Permit could be issued or not in the context of programming construction works, reference should be made to the relevant technical memoranda issued under the Noise Control Ordinance. Where no sound power levels can be found in the technical memoranda under the Noise Control Ordinance, reference shall be made to sound power levels adopted in previous projects in Hong Kong or agreed with the Director. However, whether the Noise Control Authority would issue a Construction Noise Permit would depend on the application submitted according to the procedures laid down in the relevant technical memoranda issued under the Noise Control Ordinance rather than under the EIA process.

Rail Noise

5.5 The assessment methodology shall be agreed with the Director prior to the commencement of the assessment.

Aircraft/Helicopter Noise (Civil Aviation)

5.6 The assessment methodology shall be agreed with the Director, in consultation with the Director-General of Civil Aviation, prior to the commencement of the assessment.

5.7 For designated projects specified in Items B.1 and B.2 in Part I of the Schedule 2 to the Ordinance, noise sensitive receivers, located under or close to the aircraft flight paths of the Hong Kong International Airport (including those outside NEF 25 contour of the Hong Kong International Airport) and/or any helicopter routes, shall be assessed by making reference to the relevant information, including but not limited to aircraft flight paths and helicopter routes published in the Hong Kong Aeronautical Information Publication.

6. Consideration of Mitigation Measures

6.1 Where the predicted noise impacts exceed the applicable noise criteria, direct mitigation measures as shown below shall be considered and evaluated in an appropriate manner :

  1. treatment of source
  2. low noise road surfacing
  3. quieter construction method and quieter construction equipment
  4. alternative land use arrangement
  5. setback of buildings
  6. screening by noise tolerant buildings
  7. noise barrier/enclosure
  8. decking over
  9. extended podium
  10. building orientation
  11. architectural features
  12. acoustic windows/balconies [Note 1]
  13. special building design
Note 1: When adopting direct mitigation measures on the fa├žade of noise sensitive receivers, the mitigated noise levels shall take into account the noise reduction performance of the measures.

6.2 If mitigation measures are required on the planned land uses even after adoption of all practicable direct measures on the noise sources not controlled under the Noise Control Ordinance, the practicality of these mitigation measures shall be evaluated and confirmed with relevant authorities.

6.3 Upon exhaust of direct mitigation measures, indirect mitigation measures in the form of window insulation and air-conditioning is often the "last resort" in an attempt to abate the residual impact from noise sources not controlled under the Noise Control Ordinance, such as aircraft, road traffic and helicopter, because it will practically deprive the receivers of outdoor activities and an "open window" life style. If a compromise is necessary when there are overriding constraints on the location and design of a development, which prevent full compliance with the appropriate noise standards laid down in Annex 5, an attempt shall be made to maximize the proportion of receivers protected, using effective noise mitigation measures at sources, at path or building layout designs of the development. The remaining unprotected receivers shall be insulated using the suitable single frame double pane window types described in Table 2 of Annex 5. The acoustic insulation shall also require the provision of air conditioning systems because of the warm and humid climate in Hong Kong.

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