Appendix A          Implementation Schedule of Mitigation Measures

 

EIA Ref.

EM&A Ref.

Recommended Mitigation Measures

Objectives of the Recommended Measure & Main Concern to Address

Who to implement the measure?

Location of the measure

When to implement the measure?

What requirements or standards for the measure to achieve?

A

 

Noise Impact

 

 

 

 

 

S 3.30

2.18

Good Site Practice:

§  Only well-maintained plant shall be operated on-site and plant shall be serviced regularly during the construction program

§  Silencers or mufflers on construction equipment shall be utilized and shall be properly maintained during the construction program

§  Mobile plant, if any, shall be sited as far from NSRs as possible

§  Machines and plant (such as trucks) that may be in intermittent use shall be shut down between work periods or shall be throttled down to a minimum

§  Plant known to emit noise strongly in one direction shall, wherever possible, be orientated so that the noise is directed away from the nearby NSRs

§  Material stockpiles and other structures shall be effectively utilized, wherever practicable, in screening noise from on-site construction activities.

 

To minimize construction noise impacts

Contractor

Works areas

Construction phase

EIAO-TM

NCO

S 3.31 - 3.32

2.19

Use of quieter PME

 

To minimize construction noise impacts

Contractor

Works areas

Construction phase

EIAO-TM

NCO

S 3.33 – 3.34

3.36-3.38

2.20-2.21

2.23-2.24

Use of temporary noise barrier

 

To minimize construction noise impacts

Contractor

Works areas as shown in Figure 3.5

Construction phase

EIAO-TM

NCO

S 3.35 and Table 3.6

2.22

Use of alternative quieter construction method (the Low Impact Method)

To minimize construction noise impacts

Contractor

Part of the works area for pipe laying in Wai Ha (refer to Figure 3.5)

Construction phase

EIAO-TM

NCO

3.36 -3.38

2.23-2.24

Use of  noise enclosure

To minimize construction noise impacts

Contractor

Part of the works area for pipe laying in Wai Ha (refer to Figure 3.5)

Construction phase

EIAO-TM

NCO

B

 

Air Quality Impact

 

 

 

 

 

S4.16

3.5

Implementation of mitigation measures stipulated in the Air Pollution Control (Construction Dust) Regulation and good site practices including but not limited to the following:

§   Use of regular watering to reduce dust emissions from exposed site surfaces and unpaved road, with complete coverage, particularly during dry weather;

§   Use of frequent watering for particularly dusty static construction areas and areas close to ASRs;

§   Tarpaulin covering of all dusty vehicle loads transported to, from and between site location;

§   Establishment and use of vehicle wheel and body washing facilities at the exit points of the site;

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

§   Stockpiled excavated materials should be covered with tarpaulin, and should be removed off-site within 24 hours to avoid any odour nuisance arising.

 

To minimize construction dust impacts

Contractor

Construction Sites

Construction Phase

EIAO-TM

C

 

Water Quality Impact

 

 

 

 

 

S5.29

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

4.5

Construction Site Run-off and Drainage:

§   Before commencing any site formation work, all sewer and drainage connections shall be sealed to prevent debris, soil, sand etc. from entering public sewers/drains.

§   Temporary ditches shall be provided to facilitate run-off discharge into appropriate watercourses, via a silt retention pond.  No site run-off shall enter the fishponds at Shuen Wan.

§   Sand/silt removal facilities such as sand traps, silt traps and sediment basins shall be provided to remove sand/silt particles from runoff to meet the requirements of the Technical Memorandum standard under the Water Pollution Control Ordinance.  The design of silt removal facilities shall be based on the guidelines provided in ProPECC PN 1/94.  All drainage facilities and erosion and sediment control structures shall be inspected monthly and maintained to ensure proper and efficient operation at all times and particularly during rainstorms. 

§   Water pumped out from excavated pits shall be discharged into silt removal facilities.

§   During rainstorms, exposed slope/soil surfaces shall be covered by a tarpaulin or other means, as far as practicable.  Other measures that need to be implemented before, during, and after rainstorms as summarized in ProPECC PN 1/94 shall be followed.

§   Exposed soil areas shall be minimized to reduce potential for increased siltation and contamination of runoff. 

§   Earthwork final surfaces shall be well compacted and subsequent permanent work or surface protection shall be immediately performed to reduce the potential of soil erosion.

§   Open stockpiles of construction materials or construction wastes on-site of more than 50 m3 shall be covered with tarpaulin or similar fabric during rainstorms.

 

 

To minimize water quality impacts

Contractor

Works sites

Construction phase

ProPECC PN 1/94 Construction Site Drainage

S5.30

4.7

Further precautionary measures during rainy season:

n   For the construction of the box culvert next to the existing channel of the Wai Ha River, sand bags should be deployed around the boundary of the works trench to prevent muddy water ingress into the adjacent CA or Wai Ha River. Sand bags should also be used to surround the excavated trench.  Generally, the sand bags will be placed up to a height of 300mm to provide adequate allowance for the built-up water level during rainstorm event. With sand bags in place, surface runoff will be intercepted and flow to Wai Ha River or collected by the existing drainage system as usual.

n   Sheet-piles, which would be installed around the works trench near the Conservation Area, would be extended above ground level for about 2m to serve as hoardings to isolate the works site.

n   Tarpulin sheets would be used to cover the excavation areas during heavy rainstorms.  This would prevent the ingress of rainwater into the trench minimising the risk of muddy water getting into Wai Ha River and the adjacent Conservation Area.

n   Any concrete washing water would be contained inside the works site surrounded by the extended sheet piles.  A pump sump at the bottom of the trench would be provided to pump any excess water during concrete washing.

n   Stockpiling the excavated materials adjacent to the Conservation Area would not be allowed.  The excavated materials would be either removed off site immediately after excavation, or stockpile at location(s) away from the Conservation Area.  The stockpile locations shall be approved by the site engineer.

 

To minimize water quality impacts to the designated Conservation Area

Contractor

Works areas near the Conservation Area

Rainy seasons during construction phase

EIAO-TM

Water Pollution Control Ordinance (WPCO)

S5.31-S5.32

4.8-4.9

General Construction Activities:

n   Debris and refuse generated on-site should be collected, handled and disposed of properly to avoid entering the Wa Ha River and fish ponds at Shuen Wan.  Stockpiles of cement and other construction materials should be kept covered when not being used. 

n   Oils and fuels should only be used and stored in designated areas which have pollution prevention facilities.  To prevent spillage of fuels and solvents to nearby water bodies, all fuel tanks and storage areas should be provided with locks and be sited on sealed areas, within bunds of a capacity equal to 110% of the storage capacity of the largest tank.  The bund should be drained of rainwater after a rain event.

 

To minimize water quality impacts

Contractor

Works sites

Construction phase

EIAO-TM

WPCO

S5.33

4.10

Sewage from Construction Workforce:

n   Temporary sanitary facilities, such as portable chemical toilets, should be employed on-site.  A licensed contractor would be responsible for appropriate disposal and maintenance of these facilities. 

 

To minimize water quality impacts

Contractor

Works sites

Construction phase

EIAO-TM

WPCO

S5.34

4.11

River Channel Excavation Works:

§  The excavation works within the upstream end of the existing river channel of the Wai Ha River for the construction of the proposed box culvert shall be carried out in dry condition.   Containment measures such as bunds and barriers shall be used within the affected length of the river channel and the excavation works restricted to within an enclosed dry section of the channel. The excavation works within Wai Ha River shall be restricted to the period from October to April.

 

To minimize water quality impacts

Contractor

Works sites

Construction phase

EIAO-TM

WPCO

D

 

Waste Management Implications

 

 

 

 

 

S6.20 – 6.22

5.5

Good site practices:

§  Nomination of approved personnel, such as a site manager, to be responsible for good site practices and making arrangements for collection of all wastes generated at the site and effective disposal to an appropriate facility.

§  Training of site personnel in proper waste management and chemical waste handling procedures.

§  Provision of sufficient waste disposal points and regular collection for disposal.

§  Appropriate measures to minimise windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers.

§  Separation of chemical wastes for special handling and appropriate treatment at the Chemical Waste Treatment Facility. 

§  Regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors.

§  A Waste Management Plan should be prepared and submitted to the Engineer for approval.  One may make reference to ETWB TCW No. 15/2003 for details.

§  A recording system for the amount of wastes generated, recycled and disposed (including the disposal sites) should be proposed.

 

To reduce waste management impacts

Contractor

Works sites

Construction phase

ETWB TCW No.19/2005

ETWB TCW No.31/2004

 

S6.23- 6.24

5.7

Waste reduction measures:

§  Segregation and storage of different types of waste in different containers, skips or stockpiles to enhance reuse or recycling of materials and their proper disposal.

§  To encourage collection of aluminium cans by individual collectors, separate labelled bins shall be provided to segregate this waste from other general refuse generated by the work force.

§  Any unused chemicals or those with remaining functional capacity shall be recycled.

§  Maximising the use of reusable steel formwork to reduce the amount of C&D material.

§  Proper storage and site practices to minimise the potential for damage or contamination of construction materials.

§  Plan and stock construction materials carefully to minimise amount of waste generated and avoid unnecessary generation of waste.

 

To achieve waste reduction

Contractor

Works sites

Construction phase

EIAO-TM

S6.25- 6.26

5.9

Construction & Demolition (C&D) Material:

§ Excavated material with suitable characteristics/size should be reused on-site as fill material as far as practicable, such as for backfilling of the box culvert and drainage pipe works. 

§ Suitable areas should be designated within the works site boundaries for temporary stockpiling of C&D material.

§ Within stockpile areas, the following measures should be taken to control potential environmental impacts or nuisance:

-      covering material during heavy rainfall;

-      locating stockpiles to minimise potential visual impacts; and

-      minimizing land intake of stockpile areas as far as possible.

§  When disposing C&D material at a public filling area, the material shall only consist of soil, rock, concrete, brick, cement plaster/mortar, inert building debris, aggregates and asphalt.  The material shall be free from marine mud, household refuse, plastic, metals, industrial and chemical waste, animal and vegetable matter, and other material considered to be unsuitable by the Filling Supervisor. 

 

To minimize off-site disposal of C&D material

To minimize environmental impacts during the handling of C&D material

Contractor

Works sites

Construction phase

EIAO-TM

S6.27

5.10

Chemical waste:

§ Contractor should register with the EPD as a Chemical Waste Producer and to follow the guidelines stated in the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes.

§ Good quality containers compatible with the chemical wastes should be used, and incompatible chemicals should be stored separately.

§ Appropriate labels should be securely attached on each chemical waste container indicating the corresponding chemical characteristics of the chemical waste, such as explosives, flammable, oxidizing, irritant, toxic, harmful, corrosive, etc. 

§ The Contractor should use a licensed collector to transport and dispose of the chemical wastes generated at the Chemical Waste Treatment Centre at Tsing Yi, or other licenced facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

 

To minimize environmental impacts during the handling, transportation and disposal of chemical waste

Contractor

Works sites

Construction phase

EIAO-TM

Waste Disposal (Chemical Waste) (General) Regulation

S6.28

5.11

General refuse:

§ It should be stored in enclosed bins or compaction units separate from C&D material.

§ A reputable waste collector should be employed by the contractor to remove general refuse from the site, separately from C&D material.

§ An enclosed and covered area is preferred to reduce the occurrence of 'wind blown' light material. 

 

To minimize environmental impacts during the handling and transportation of general refuse

Contractor

Works sites

Construction phase

EIAO-TM

E

 

Ecological Impact

 

 

 

 

 

S. 7.95

6.6

n   Sheet-pilings, which will be installed around the trench of excavation, should be extended above ground level for ~2m to act as hoarding to isolate the works site.

 

n   The trenching works for the construction of the proposed box culvert should be carried out in phases, with a trench length of not more than 120m in each phase.  The trench should be backfilled and compacted with suitable materials upon completion of each phase of the construction works.

To minimize the impacts on the stream and natural river bank

Contractor

Whole site

Construction Phase

EIAO-TM

S7.117

6.6

n   The construction of intercept point of twin cell box culvert at the upstream of Wai Ha River should be confined to only one side of the river bank.

 

n   To restore and enhance the ecological value of the stream, the affected river bank should be reinstated to its original condition or lined with rock-filled gabion.

 

n   Planting pits should be provided in the gabion bank to allow the re-establishment of riparian vegetation.

 

n   The existing natural riverbed and substrates should be retained and the natural pool-riffle sequence should be re-created in the new channel bed.

To minimize the impacts on the stream and natural river bank

Contractor

Whole site

Construction Phase

EIAO-TM

S 7.118

6.7

n  All works carried out within the river channel of Wai Ha River should be carried out from October to April, with construction carried out by land-based plant.

 

n  Works within river/stream channels should be restricted to an enclosed dry section of the river, with containment measures such as bunds and barriers used within the river to minimize the impacts upon the downstream water body.

 

n  Site runoff should be directed towards regularly cleaned and maintained silt traps and oil/grease separators to minimize the risk of sedimentation and pollution of river water.

 

n  The silt and oil/grease separators should be appropriately designed for the local drainage and ground conditions.

 

n  To minimize leakage and loss of sediments during excavation in narrow channels, tightly sealed closed grab excavators should be deployed where material to be handled is wet.

To minimise sedimentation/ water quality impacts

 

Contractor

 

 

 

 

 

 

 

 

 

 

Whole Site

Construction Phase

EIAO-TM

S 7.119

6.8

n   The construction of the proposed box-culvert would have the potential to directly impact a few individual of a plant species of conservation interest (Hong Kong Pavetta, Pavetta hongkongensis). The affected individuals should be transplanted to a suitable nearby habitats prior to the construction phase.

 

n   A detailed vegetation survey of the affected species of conservation interest should be conducted by a suitably qualified botanist/ecologist to identify the affected individuals in order to provide details for transplantation scheme.

 

n   Transplantation should be supervised by a suitably qualified botanist/horticulturalist. A detailed transplantation methodology should be formulated during the detailed design stage of this Project.

To protect plant species of conservation interest

 

Contractor/ qualified botanist/horticulturalist

Whole site

Construction Phase

EIAO-TM

S 7.120

6.9

n   Noise mitigation measures such as the use of quieter construction plant and temporary noise barriers should be implemented to minimize disturbance to habitats adjacent to the works areas.

 

n   Temporary noise barriers should be used during the construction of the box-culvert along Tung Tsz Road, the floodwater pumping station, the mechanical gate, and drainage pipe to minimize potential construction phase disturbance to ardeids and avifauna foraging in marsh habitat.

 

n   Noise generating construction works near the Shuen Wan Egretry SSSI should be avoided as far as practicable during the breeding season (March to June) of the ardeids.

 

n   Works near the SSSI (i.e. installation of mechanical gate) should be restricted to be executed outside the breeding season by provision of special conditions in the contract document.

 

n   Hoardings with minimum height of 2m should be set up along the south side of the proposed box culvert works area adjacent to the marsh, extending at least 20m at both ends, throughout the construction period.

 

To minimise disturbance impacts.

 

Contractor

Whole site

Construction Phase

EIAO-TM

S 7.121

6.10

n  Placement of equipment or stockpile in designated works areas and access routes selected on existing disturbed land to minimise disturbance to natural or moderate-high ecological value habitats.

To minimise disturbance to habitats.

Contractor

Whole site

Construction Phase

 EIAO-TM

S 7.121

6.10

n  Construction activities should be restricted to work areas that would be clearly demarcated. The work areas should be reinstated after completion of the works.

To minimise disturbance to natural habitats outside works area.

Contractor

Whole site

Construction Phase

 EIAO-TM

S 7.121

6.10

n   Waste skips should be provided to collect general refuse and construction wastes. The wastes would be disposed of timely and properly off-site.

To minimise disturbance to habitats.

Contractor

Whole site

Construction Phase

 EIAO-TM

S 7.121

6.10

n   General drainage arrangements should include sediment and oil traps to collect and control construction site run-off.

To minimise sedimentation/ water quality impacts

 

Contractor

Whole site

Construction Phase

 EIAO-TM

S 7.121

6.10

n  Open burning on works sites is illegal, and should be strictly prohibited.

To prevent accidental hill-fires.

Contractor

Whole site

Construction Phase

 EIAO-TM

S 7.122

6.11

n  De-silting should be limited to the dry season.

To minimise sedimentation/ water quality impacts

 

Maintenance parties of the channel

Whole site

Operation Phase

EIAO-TM

S 7.122

6.11

n   Waste material produced during de-silting should be disposed of in a timely and appropriate manner.

To minimise sedimentation/ water quality impacts

 

Maintenance parties of the channel

Whole site

Operation Phase

EIAO-TM

S 7.123

6.12

n   Planting of trees should be provided within the project area to compensate for the unavoidable loss of approximately 0.08ha secondary woodland habitat due to the Project.

n   Planting of trees and other vegetation within project area along the banks of Wai Ha River and Tung Tsz Road should be carried out to provide compensation for unavoidable tree-felling and loss of riparian vegetation resulting from the Project.

n   The compensatory planting should make use of native plant species with flowers/fruits attractive to wildlife.

To compensate the loss of vegetation

 

Contractor

Whole site

Construction Phase

EIAO-TM

S 7.124

6.13

n   Compensation would be required for the loss of a small area of marsh habitat (about 0.30ha) within the CA resulting from the construction of the box-culvert.

 

n   An existing low ecological value recreational fishpond on government land adjacent to the marsh would be used as a proposed area (about 0.8ha) for the compensation for the marsh as well as secondary woodland habitats loss (0.08ha).

 

n   The pond should be enhanced by removing boardwalks around the existing pond, and restoring vegetation along the pond bunds, and it would be re-profiled to provide areas of shallow water (approximately 15-50cm deep), creating a suitable foraging habitat for avifauna, particularly ardeids and other waders.

 

n   Screen planting of shrubs and trees along the south-eastern bund of the pond should be implemented to minimise disturbance to avifauna and other wildlife from the adjacent recreational fishpond. The enhanced pond is expected to provide a moderate-high ecological value wetland habitat.

 

To compensate the loss of marsh habitat and enhance the quality  compensatory  habitat

 

Contractor / qualified ecologist

The recreational fish pond located to the southwest of the existing Tung Tsz Nursery

Construction Phase

EIAO-TM

F

 

Landscape and Visual

 

 

 

 

 

Table 8.4

7.6

Visual screen, contaminant/ sediment control, pollution control, liaison with nursery, protection of existing trees with works area and construction light are used or practiced to mitigate the impacts during construction phase.

To mitigate the landscape and visual impacts during construction phase.

Contractor

Whole site

Construction Phase

EIAO-TM

Table 8.4

7.7

Viewing area formation, architectural design for pump house, landscape design for pump house, enhancement planting along Tung Tsz Road, sufficient soil depth for enhancement planting, transplanting of trees to adjacent locations, preparation for transplanting and reinstatement of affected area are practiced to mitigate the impacts during operational phase.

To mitigate the landscape and visual impacts during the operational phase.

Contractor

Whole site

Detail Design / Operational Phase

EIAO-TM