Appendix 4.2  Construction Noise Impact Assessment
(A2)  Proposed Powered Mechanical Equipment for Various Construction Tasks for NSR BOS (during examination period)
- Unmitigated Scenario
(I)  Raw Water Mains Construction
Activity A - Excavation of Trench / Breaking up Pavement
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Excavator (mini)	BS C.3, item 108	1	97	100%	0	97
Breaker, mini-robot mounted	CNP 031	-	115	100%	-	-
Air Compressor	CNP 002	1	102	100%	0	102
Lorry	CNP 141	1	112	50%	0	109
					Total	110
Activity B - Installation of Pipes and Bedding
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Mobile crane (mini)	BS C.7, item 118	1	99	100%	0	99
Lorry (mini)	CNP 141	1	112	50%	0	109
					Total	109
Activity C - Backfilling
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Compactor	CNP 050	2	105.0	100%	0	108
					Total	108
Activity D - Reinstating Road Surface
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Lorry (mini)	CNP 141	1	112	50%	0	109
Concrete mixer (electric)	CNP 045	1	96	100%	0	96
Air Compressor	CNP 002	1	102	100%	0	102
Generator	CNP 101	1	108	100%	0	108
Vibratory poker hand-held	CNP 170	1	113	100%	0	113
					Total	116
(II)  Demolition of Pui O Raw Water Pumping Station
Activity A - General Site Clearance / Demolition Works
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Air compressor	CNP 003	1	104	100%	0	104
Hand-held pneumatic breaker	CNP 026	1	114	100%	0	114
Backhoe with hydraulic breaker	CNP 028	1	122	100%	0	122
Mobile Crane	CNP 048	1	112	100%	0	112
Dump truck	CNP 067	1	117	100%	0	117
Excavator	CNP 081	1	112	100%	0	112
Lorry mounted Crane	CNP 048	1	112	100%	0	112
Generator	CNP 101	1	108	100%	0	108
					Total	125
(III)  Construction of Pui O Raw Water Pumping Station
Activity A - Foundation
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Air compressor	CNP 003	1	104	100%	0	104
Piling Rig	CNP 164/165	1	115	100%	0	115
Backhoe with hydraulic breaker	CNP 028	1	122	100%	0	122
Mobile Crane	CNP 048	1	112	100%	0	112
Dump truck	CNP 067	1	117	100%	0	117
Excavator	CNP 081	1	112	100%	0	112
Water Pump	CNP  281	1	88	100%	0	88
Generator	CNP 101	1	108	100%	0	108
					Total	124
Activity B - Superstructural Works
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Air compressor	CNP 003	1	104	100%	0	104
Bar Bender and Cutter	CNP  021	1	90	100%	0	90
Concrete Mixer Truck	CNP 028	1	122	100%	0	122
Concrete Poker Vibrator	CNP 170	1	113	100%	0	113
Concrete Pump	CNP  047	1	109	100%	0	109
Mobile Crane	CNP 048	1	112	100%	0	112
Dump truck	CNP 067	1	117	100%	0	117
Excavator	CNP 081	1	112	100%	0	112
Generator	CNP 101	1	108	100%	0	108
					Total	124
Activity C - Installation of E&M Equipment and Commissioning & Testing
Powered Mechanical Equipment	TM Ref./	No. of Items	SWL/Item	On-time	Barrier	Total SWL
(PME)	other Ref.		dB(A)	%	dB(A)	dB(A)
Mobile Crane	CNP  048	1	112	100%	0	112
Lorry	CNP  141	1	112	50%	0	109
					Total	114
Note:
BS  BS5228 (1997) Part 1 Noise and Vibration Control on Construction and open sites