9 SUMMARY OF ENVIRONMENTAL OUTCOMES

9.1 Introduction

9.1.1.1 This EIA study predicted that, with the implementation of the recommended mitigation measures, the EMSD Hong Kong Workshop Project would be environmentally acceptable with no adverse residual impacts on the population and environmentally sensitive resources. Table 9.1 summarises the environmental outcomes and benefits that accrued from the environmental considerations and analysis during the EIA process and the implementation of environmental control measures of the Project. The requirements for the EM&A programme have been recommended, where necessary, to check for the compliance with environmental legislation and standards.

Table 9.1 Summary of Key Environmental Outcomes

Area/Issue	Environmental Outcomes and Mitigation Measures
The EMSD Hong Kong Workshop Project	Based on the preferred option of this workshop, the proposed vehicle workshop will be constructed in the form of a low-rise canopy structure with minimum clear headroom of 5.2m covering approximately 1,200m² of the site. The canopy will provide covered space for carrying out general vehicle repair and maintenance activities for small and light vehicles (i.e. motorcycle, saloon cars and light vans) in the government fleet. Major vehicle body repair, and traffic accident repair and vehicle body painting will not be carried out in this workshop. The preliminary schedule of facilities at the proposed workshop is as follows: · 17 no. of vehicle hoists for vehicle and motorcycle repair or maintenance; · 3 no. of store rooms; · 1 no. of dangerous goods (DGs) store; · 1 no. of roller brake tester; · 1 no. of motorcycle brake tester; · 1 no. of motorcycle speedometer; · 1 no. of tyre changer; · 1 no. of wheel balancer; · A 2-storey office and store; · An F.S. pump room; · A main switch room; · A compressor room with 2 compressors and 2 air dryers; · A security room; and · Toilets.
Environmentally Friendly Design Recommended	The size of this proposed single-storey workshop is small (only about 2,080 m²) and the flexibility to distribute individual repairing and maintenance processes within the workshop is comparatively low. The following design options were considered and reviewed, however, in order to optimise the operational and environmental benefits of the facility: · Servicing Capacity Design: The optimisation of the design to service a smaller number and types of vehicles (small and light vehicles, i.e. motorcycle, saloon cars and light vans) in the workshop in order to reduce any potential environmental issues during the operation phase, e.g. vehicular emissions, noise, wastewater, chemical waste, etc; · Building Design: The use of a simple open steel shed design instead of a typical building design of the workshop so as to reduce the duration of construction works and hence potential environmental impacts during the construction phase, e.g. construction dust, noise, site effluent, C&D waste, etc; · Local Exhaust Design: The enhancement of utilising natural ventilation by providing a 5.2m high clearance instead of using mechanical ventilation systems for local exhaust of emissions from the workshop so as to minimise any potential noise impacts to the nearby sensitive receivers during the operation phase. As a result of the environmental benefits of the alternatives considered with respect to revising the design to service a smaller number and types of vehicles, using an open steel shed design and using natural ventilation, these design alternatives have been adopted in the preferred scheme. Construction of the workshop would be comparatively uncomplicated as it mainly involves the erection of a shed, underneath which the vehicle repairing and maintenance activities would be carried out. As such, consideration of alternatives was focused on the design of the foundation works and two typical construction methods being studied and compared, namely Steel-H Driven Piling and Raft Foundations. As the benefits and dis-benefits concerning dust, run-off and the amount of waste are not significantly different between the two techniques and can be adequately controlled in both cases, it is considered that the ability to generate noise is the most notable environmental factor. Percussive piling can generate significant noise and vibration disturbance to the surrounding sensitive receivers and as a result of this, and the constraints imposed by this technique on the programme, the raft foundation technique is considered to be overall environmentally preferable and has been selected for the preferred option.
Population and Environmentally Sensitive Areas Protected	With the adoption of the environmentally friendly design in the preferred option, the major environmental sensitive receivers will be protected. This preferred option is determined based on the comparison of the environmental benefits and dis-benefits of the various options and alternatives and has been selected on the basis that it minimises environmental impacts and presents overall environmental benefits over the other options and is considered the optimum scheme from an environmental perspective.
Noise	With the use of quieter construction plant including concrete lorry mixer, concrete pump, dump truck, tracked excavator, tracked mobile crane (132kW, 55t), etc, and implementation of noise barriers at Drill rig, rotary type (diesel), Concrete pump and Tracked excavator, adverse impact to the NSRs would not be anticipated during the construction phase. Good site practices have been recommended to ensure adverse impact would not be anticipated. In the operation phase, after implementation of noise barrier at the motorcycle speedometer calibrator and noise curtain at the western site boundary, adverse impact would not be anticipated, even though the operation would be extended beyond July 2017 as planned.
Air Quality	There would be no major earthwork carried out for the site formation works for the Project site. With the implementation of sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation, adverse construction dust impact would not be anticipated, e.g. · Use of regular watering, to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather. · Use of frequent watering for particularly dusty construction areas and areas close to ASRs. · Side enclosure and covering of any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to frequent usage, watering should be applied to aggregate fines. · Open temporary stockpiles should be avoided or covered. Prevent placing dusty material storage piles near ASRs. · Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations. · Establishment and use of vehicle wheel and body washing facilities at the exit points of the site. · Imposition of speed controls for vehicles on unpaved site roads. 8km per hour is the recommended limit. · Routing of vehicles and positioning of construction plant should be at the maximum possible distance from ASRs. · Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides. · Loading, unloading, transfer, handling or storage of large amount of cement or dry PFA should be carried out in a totally enclosed system or facility, and any vent or exhaust should be fitted with an effective fabric filter or equivalent air pollution control system. For the operation of the workshop, adverse air quality impacts would not be anticipated as there would only be minor number of vehicles involved in the operation of the workshop, even though the operation would be extended beyond July 2017 as planned.
Water Quality	Water quality impacts from land-based construction activities would be controlled by implementing the recommended mitigation measures, such as control measures on site run-off and drainage from the works sites and barging points to minimise construction run-off, tunnelling wastewater, and particularly on-site treatment of any contaminated wastewater prior to discharge. During the operational phase, the sewerage and sewage treatment implications were assessed and adverse water quality impact would not be anticipated, provided that the recommended mitigation measures are incorporated in the design and implemented, even though the operation would be extended beyond July 2017 as planned.
Waste Management Implication and Land Contamination	Construction waste arisings were identified based on the proposed construction activities comprising C&D materials, chemical waste from maintenance of construction plant and equipment, and general refuse from on-site staff and workers. Provided that the identified waste arisings are to be handled, transported and disposed of using approved methods and the recommended good site practices are to be followed, adverse environmental impacts would not be expected during the construction phase. The types of waste generated during the operation of the EMSD Hong Kong Workshop Project would be general refuse from the staff, and chemical wastes from the repairing and maintenance activities. With the implementation of the recommended waste handling procedures, impacts arising from the operation of the workshop would not be anticipated. Based on the recorded nature of past and present land use activities of the Project site, it is anticipated that there were no potentially contaminating activities occurred and no potential land contamination sources and issues were identified. During the operation phase, potential contamination sources were identified, e.g. repairing and maintenance areas inside the workshop, dangerous goods and chemical storage areas, and chemical waste storage areas. With the development and implementation of the Preventive and Precautionary Plan recommended in this EIA study, including aspects on the storage of chemicals and chemical wastes, emergency procedures, spillage/leakage of liquid chemical/waste at storage and maintenance areas, record of incidents, procedures for disposal of wastes, etc, significant land contamination impact would not be anticipated, even though the operation would be extended beyond July 2017 as planned..
Landscape and Visual	During the construction phase, the Project site will be screened by the site hoarding to minimize any visual impacts to viewers at ground level. Given the site can be resumed for its originally planned land uses in the OZP after the termination of the Temporary Government Land Allocation, no significant landscape and visual impacts and corresponding cumulative impacts of the Project are anticipated in the long term. The Project will result in the felling of 10 common native trees and removal of 11 weedy (i.e. Leucaena leucocephala)/dead trees within the Project site. Due to the limited size of the Project site and the proposed land use (a workshop), no space would be allowed for the on-site tree compensation. However, after tree felling and site clearance, the proposed workshop can still be well screened at the southern boundary by the retained trees and the existing footbridge at Wing Tai Road. The resulting landscape and/or visual impacts from proposed tree felling without mitigation measures (e.g. on-site tree compensation) are therefore considered low. Off-site tree compensation would be implemented at the EMSD Tuen Mun Vehicle Servicing Station, 202 Lung Mun Road, Siu Lang Shui, Tuen Mun. The compensatory planting regime would include planting of thirty-one (31) heavy standard trees (assuming of trunk diameter at least 75mm) of aggregated trunk diameters of 2,325mm to compensate for the 10 trees lost (of aggregated trunk diameters 2,321mm) due to the proposed Project. The Project will comprise only low-rise temporary structures (including the steel cover and the facilities) with dull green or light green finishes to blend in with the surrounding environment. Rolling plastic curtains would be installed along the western boundary of the Project site to screen off the maintenance works activities during the operation phase such that visual nuisance to adjacent VSRs can be avoided. Due to the limited footprint of the Project site and the existing development setting, the workshop can only be occasionally/rarely viewed by most of the identified visually sensitive receivers in the EIA study area. Except for the travellers at Sheung On Street (VSR-T1) who are considered to have low to medium sensitivity to visual change to the Project site, other identified VSRs are considered to have low sensitivity to visual change to the Project site.

Area/Issue

Environmental Outcomes and Mitigation Measures

The EMSD Hong Kong Workshop Project

Based on the preferred option of this workshop, the proposed vehicle workshop will be constructed in the form of a low-rise canopy structure with minimum clear headroom of 5.2m covering approximately 1,200m² of the site. The canopy will provide covered space for carrying out general vehicle repair and maintenance activities for small and light vehicles (i.e. motorcycle, saloon cars and light vans) in the government fleet. Major vehicle body repair, and traffic accident repair and vehicle body painting will not be carried out in this workshop.

The preliminary schedule of facilities at the proposed workshop is as follows:

· 17 no. of vehicle hoists for vehicle and motorcycle repair or maintenance;

· 3 no. of store rooms;

· 1 no. of dangerous goods (DGs) store;

· 1 no. of roller brake tester;

· 1 no. of motorcycle brake tester;

· 1 no. of motorcycle speedometer;

· 1 no. of tyre changer;

· 1 no. of wheel balancer;

· A 2-storey office and store;

· An F.S. pump room;

· A main switch room;

· A compressor room with 2 compressors and 2 air dryers;

· A security room; and

· Toilets.

Environmentally Friendly Design Recommended

The size of this proposed single-storey workshop is small (only about 2,080 m²) and the flexibility to distribute individual repairing and maintenance processes within the workshop is comparatively low. The following design options were considered and reviewed, however, in order to optimise the operational and environmental benefits of the facility:

· Servicing Capacity Design: The optimisation of the design to service a smaller number and types of vehicles (small and light vehicles, i.e. motorcycle, saloon cars and light vans) in the workshop in order to reduce any potential environmental issues during the operation phase, e.g. vehicular emissions, noise, wastewater, chemical waste, etc;

· Building Design: The use of a simple open steel shed design instead of a typical building design of the workshop so as to reduce the duration of construction works and hence potential environmental impacts during the construction phase, e.g. construction dust, noise, site effluent, C&D waste, etc;

· Local Exhaust Design: The enhancement of utilising natural ventilation by providing a 5.2m high clearance instead of using mechanical ventilation systems for local exhaust of emissions from the workshop so as to minimise any potential noise impacts to the nearby sensitive receivers during the operation phase.

As a result of the environmental benefits of the alternatives considered with respect to revising the design to service a smaller number and types of vehicles, using an open steel shed design and using natural ventilation, these design alternatives have been adopted in the preferred scheme.

Construction of the workshop would be comparatively uncomplicated as it mainly involves the erection of a shed, underneath which the vehicle repairing and maintenance activities would be carried out. As such, consideration of alternatives was focused on the design of the foundation works and two typical construction methods being studied and compared, namely Steel-H Driven Piling and Raft Foundations. As the benefits and dis-benefits concerning dust, run-off and the amount of waste are not significantly different between the two techniques and can be adequately controlled in both cases, it is considered that the ability to generate noise is the most notable environmental factor. Percussive piling can generate significant noise and vibration disturbance to the surrounding sensitive receivers and as a result of this, and the constraints imposed by this technique on the programme, the raft foundation technique is considered to be overall environmentally preferable and has been selected for the preferred option.

Population and Environmentally Sensitive Areas Protected

With the adoption of the environmentally friendly design in the preferred option, the major environmental sensitive receivers will be protected. This preferred option is determined based on the comparison of the environmental benefits and dis-benefits of the various options and alternatives and has been selected on the basis that it minimises environmental impacts and presents overall environmental benefits over the other options and is considered the optimum scheme from an environmental perspective.

Noise

With the use of quieter construction plant including concrete lorry mixer, concrete pump, dump truck, tracked excavator, tracked mobile crane (132kW, 55t), etc, and implementation of noise barriers at Drill rig, rotary type (diesel), Concrete pump and Tracked excavator, adverse impact to the NSRs would not be anticipated during the construction phase. Good site practices have been recommended to ensure adverse impact would not be anticipated.

In the operation phase, after implementation of noise barrier at the motorcycle speedometer calibrator and noise curtain at the western site boundary, adverse impact would not be anticipated, even though the operation would be extended beyond July 2017 as planned.

Air Quality

There would be no major earthwork carried out for the site formation works for the Project site. With the implementation of sufficient dust suppression measures as stipulated under the Air Pollution Control (Construction Dust) Regulation, adverse construction dust impact would not be anticipated, e.g.

· Use of regular watering, to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather.

· Use of frequent watering for particularly dusty construction areas and areas close to ASRs.

· Side enclosure and covering of any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to frequent usage, watering should be applied to aggregate fines.

· Open temporary stockpiles should be avoided or covered. Prevent placing dusty material storage piles near ASRs.

· Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations.

· Establishment and use of vehicle wheel and body washing facilities at the exit points of the site.

· Imposition of speed controls for vehicles on unpaved site roads. 8km per hour is the recommended limit.

· Routing of vehicles and positioning of construction plant should be at the maximum possible distance from ASRs.

· Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides.

· Loading, unloading, transfer, handling or storage of large amount of cement or dry PFA should be carried out in a totally enclosed system or facility, and any vent or exhaust should be fitted with an effective fabric filter or equivalent air pollution control system.

For the operation of the workshop, adverse air quality impacts would not be anticipated as there would only be minor number of vehicles involved in the operation of the workshop, even though the operation would be extended beyond July 2017 as planned.

Water Quality

Water quality impacts from land-based construction activities would be controlled by implementing the recommended mitigation measures, such as control measures on site run-off and drainage from the works sites and barging points to minimise construction run-off, tunnelling wastewater, and particularly on-site treatment of any contaminated wastewater prior to discharge.

During the operational phase, the sewerage and sewage treatment implications were assessed and adverse water quality impact would not be anticipated, provided that the recommended mitigation measures are incorporated in the design and implemented, even though the operation would be extended beyond July 2017 as planned.

Waste Management Implication and Land Contamination

Construction waste arisings were identified based on the proposed construction activities comprising C&D materials, chemical waste from maintenance of construction plant and equipment, and general refuse from on-site staff and workers. Provided that the identified waste arisings are to be handled, transported and disposed of using approved methods and the recommended good site practices are to be followed, adverse environmental impacts would not be expected during the construction phase. The types of waste generated during the operation of the EMSD Hong Kong Workshop Project would be general refuse from the staff, and chemical wastes from the repairing and maintenance activities. With the implementation of the recommended waste handling procedures, impacts arising from the operation of the workshop would not be anticipated.

Based on the recorded nature of past and present land use activities of the Project site, it is anticipated that there were no potentially contaminating activities occurred and no potential land contamination sources and issues were identified. During the operation phase, potential contamination sources were identified, e.g. repairing and maintenance areas inside the workshop, dangerous goods and chemical storage areas, and chemical waste storage areas. With the development and implementation of the Preventive and Precautionary Plan recommended in this EIA study, including aspects on the storage of chemicals and chemical wastes, emergency procedures, spillage/leakage of liquid chemical/waste at storage and maintenance areas, record of incidents, procedures for disposal of wastes, etc, significant land contamination impact would not be anticipated, even though the operation would be extended beyond July 2017 as planned..

Landscape and Visual

During the construction phase, the Project site will be screened by the site hoarding to minimize any visual impacts to viewers at ground level. Given the site can be resumed for its originally planned land uses in the OZP after the termination of the Temporary Government Land Allocation, no significant landscape and visual impacts and corresponding cumulative impacts of the Project are anticipated in the long term.

The Project will result in the felling of 10 common native trees and removal of 11 weedy (i.e. Leucaena leucocephala)/dead trees within the Project site. Due to the limited size of the Project site and the proposed land use (a workshop), no space would be allowed for the on-site tree compensation. However, after tree felling and site clearance, the proposed workshop can still be well screened at the southern boundary by the retained trees and the existing footbridge at Wing Tai Road. The resulting landscape and/or visual impacts from proposed tree felling without mitigation measures (e.g. on-site tree compensation) are therefore considered low.

Off-site tree compensation would be implemented at the EMSD Tuen Mun Vehicle Servicing Station, 202 Lung Mun Road, Siu Lang Shui, Tuen Mun. The compensatory planting regime would include planting of thirty-one (31) heavy standard trees (assuming of trunk diameter at least 75mm) of aggregated trunk diameters of 2,325mm to compensate for the 10 trees lost (of aggregated trunk diameters 2,321mm) due to the proposed Project.

The Project will comprise only low-rise temporary structures (including the steel cover and the facilities) with dull green or light green finishes to blend in with the surrounding environment. Rolling plastic curtains would be installed along the western boundary of the Project site to screen off the maintenance works activities during the operation phase such that visual nuisance to adjacent VSRs can be avoided.

Due to the limited footprint of the Project site and the existing development setting, the workshop can only be occasionally/rarely viewed by most of the identified visually sensitive receivers in the EIA study area. Except for the travellers at Sheung On Street (VSR-T1) who are considered to have low to medium sensitivity to visual change to the Project site, other identified VSRs are considered to have low sensitivity to visual change to the Project site.