CIVL 395 Environmental Impact Assessment [4] Housing Development in Tuen Mun Area 1 Proposed Bridge at Tuen Mun Area 18 HS Kan March 2007

Air Impact Assessment – CALINE4

Noise Impact Assessment

Noise measurement – A-weighting for human perception

Facade Noise Levels from Road Traffic (Extracted from The Hong Kong Planning Standards & Guidelines, Planning Department) Peak hour traffic flow (veh/h) Facade noise levels L10(1h), dB(A) - Vehicular speed (30 kph) Facade noise levels L10(1h), dB(A) - Vehicular speed (50 kph) Facade noise levels L10(1h), dB(A) - Vehicular speed (70 kph) Facade noise levels L10(1h), dB(A) - Vehicular speed (85 kph) Facade noise levels L10(1h), dB(A) - Vehicular speed (100kph)

Noise Impact Assessment Legislation, standards and criteria Noise Control Ordinance Technical Memorandum on Noise from Places other than Domestic Premises, Public Places or Construction Sites Technical Memorandum on Noise from Construction Work other than Percussive Piling Technical Memorandum on Noise from Percussive Piling Noise sensitive receivers All domestic premises, hotel, hospital, educational institution, place of public worship, library, court, arts performance facilities, etc Area Sensitivity Ratings ASR Urban / rural / low-density residential Table 1 in the Technical Memorandum Influencing factors IF (on the ASR) Presence of industrial areas, major roads, etc Basic noise levels BNL Table 2 in the Technical Memorandum Sound levels for Powered Mechanical Equipment PME Table 3 in the Technical Memorandum For summation of different sources, Table 4 in the Technical Memorandum Acceptable noise levels ANL For this exercise, you may take the ANL as being directly equal to the BNL Distance attenuation Distance attenuation in dB(A) = 20 log D + 8, where D = distance in m Table 5 in the Technical Memorandum

Outline Zoning Plan of the Bridge Site Source: The Planning Department website Government / Institution / Community Green Belt Open Space Residential (Group A)

Proposed Bridge at Tuen Mun Area 18 (1)During foundation works: bored piling machine, air compressor, excavator, steel bender, etc; (2)During pile construction: concrete truck mixer, concrete pump, vibratory poker, etc. (3)etc. Consider mainly the noise impact from powered mechanical equipment at the southern abutment at various stages, e.g.

Table 1 - Area Sensitivity Ratings (ASRs) Type of Area Containing NSRDegree to which NSR is affected by IF Not Affected Indirectly Affected Directly Affected Rural area, including country parks or village type developments ABB Low density residential area consisting of low- rise or isolated high-rise developments ABC Urban areaBCC Area other than those above BBC

Basic Noise Levels (BNLs) Time PeriodASR ABC All days during the evening (1900 to 2300 hours), and general holidays (including Sundays) during the day-time and evening (0700 to 2300 hours) All days during the night-time (2300 to 0700 hours) Table 2 of the Technical Memorandum

Table 4 - Summation of Noise Levels Difference in dB(A) between two noise levels being summed Amount in dB(A) to add to the higher noise level 0 to to to to to to more than

Control of Noise Impact  The Source  Elimination, Reduction, Shielding, Absorption  The Transmission  Breaking, Weakening  The Receiver  Shielding, Protection, Removal Source Receiver Transmission

Noise Impact Assessment Control and mitigation Construction Choice of construction method Use of silenced powered mechanical equipment Proper equipment maintenance Proper location and orientation of equipment Noise screens Good site practices Operation Reduction Containment Shielding Protecting the receiver

Cantilever Barrier at West Kowloon Expressway

Enclosure barrier at Wong Chu Road, Tuen Mun