Table 12.1    Summary Table for Site Activities, Potential Environmental Impacts and Recommended Mitigation Measures in the Coming Months

Contract No.

Major Site Activities (October to
December 2022)

Location/ Working Period

Potential Environmental Impact

Recommended Mitigation Measures

ND/2019/01

(a)       Site clearance / tree felling

Portions 1a, 1c, 2

- Construction Dust impact

- Noise Impact (Construction Phase)

- Water Quality Impact (Construction Phase)

- Waste Management (Construction Waste)

 

Air

-              Watering on exposed earth and haul road.

-              Cover the stockpiles or dusty materials.

-              Deploy water bowsers to water the haul road.

-              Deploy mist-cannon on site

-              Provide shelter with top and 3-sides for cement production activities.

-              Cover the Arsenic-containing soil.

-              Store the bulk cement in enclosed silo tank for soil treatment.

-              Close the mechanical cover of the vehicles used for transporting dusty materials.

-              Establish vehicle wheel washing facilities at vehicle exit points.

-              Speed control of site vehicles.

Noise

-              Regular inspect of construction plants in good condition.

-              Provide temporary noise screens if necessary.

-              Use of Quiet plants (QPME) and working methods if possible.

-              Sequencing operation of construction plants where practicable.

-              Shut down the machines and plant if not in use.

-              Only well-maintained plant to be operated on-site

-              Mobile plant to be sited as far away from NSRs as possible practicable.

-              Conduct noise monitoring regularly.

-              Erect silent-up noise barrier at portion 6b.

Water

-              Set up wastewater treatment system (AquaSed) on site

-              Erect soil bund / temporary drain to divert /collect surface runoff.

-              Maintain the drainage and wastewater treatment facilities.

Waste / Chemical Management

-              Sort out demolition debris and excavated materials from demolition works to recover reusable / recyclable portions

-              Provide recycling bins on site, encourage reuse and recycle as much as possible.

-              Provide drip trays for chemical containers.

-              Chemical spill kit available on site.

-              Chemical waste cabinet available on site.

-              Chemical wastes to be stored in appropriate containers and collected by a licensed chemical waste collector.

-              Delivery of yard waste to tree shredding facility for upcycling.

(b)        GI works

Portions 1a

(c)        Excavation

Portions 1b, 3, 5, 7, 9b, 10a, 10b

(d)       Construction of retaining wall

Portions 8a, 9b

(e)        Site Formation

Portions 1a, 1c, 1e, 2, 7

(f)         Removal of existing structure

Portions 1a, 1c

(g)        Construction of subway

Portions 2

(h)        Operation of HAC treatment facility

Portions 6b

(i)        Drainage works

Portions 1b, 3, 5, 6a, 7, 8a, 9b, 10a, 10b

(j)         Road Construction

Portion 1b, 5, 10a

(k)        Trenchless

Portion 8b

(l)         Construction of reservoir

Portions 8a

(m)     Sheet piling/ELS

Portion 7, 8b, 9b, 10a, 10b

ND/2019/02

(a)         Pipe Jacking

Portions 1 & 3

Air, Noise, Waste

-              Dusty works should be spray water. Idle stockpile or slop should be covered by Tarpaulin sheet properly.

-              Wheel washing should be carried out at every exit.

-              Plants should be well maintained to prevent dark smoke and oil leakage. Idle plant should be turned off.

-              Drip tray should be provided for all chemical and stationary plants.

-              No construction works shall be carried out in restricted hours (7:00 pm to 7:00 am) unless CNP is obtained.

-              Erect noise screen along site boundary.

-              Waste should be sorted and dispose according to the Waste Management Plan

-              No direct discharge of wastewater into storm drains is allowed. Wastewater must be de-silted before discharged in accordance with the water discharge license.

-              Dull green barrier and ecological measures should be implemented according to the Ecological protection plan.

(b)         Backfilling

Portion 3 & 9

Air, Noise, Waste

(c)         Concreting

Portions 3, 9 & 10

Air, Noise, Water, Waste, Ecology

(d)        Bedding & Pipe Laying

Portion 3

Air, Noise, Water, Waste, Ecology

(e)         ELS

Portions 3 & 7

Air, Noise, Water, Waste, Ecology

(f)          Sheet Pile Installation

Portions 3, 4, 5 & 7

Air, Noise, Water, Waste

(g)         Cut and Fill of Slope

Portion 7

Air, Noise, Water, Waste

ND/2019/03

(a)         Excavation & ELS

Portion 1, 1a, 2, 3, 4, 4a, 4b, 5, 5a

-     Waste

-     Air pollution

-     Noise pollution

-              Dusty works should be sprayed with water or stockpile should be covered by Tarpaulin properly.

-              Plants should have maintenance to prevent dark smoke and oil leakage. Idle plant should be turned off.

-              Drip tray should be provided for all chemical and stationary plants.

-              No construction works shall be carried out in restricted hours (7:00 pm to 7:00 am) unless CNP is granted.

-              Waste should be sorted and disposed according to Waste Management Plan.

-              No direct discharge of wastewater into storm water drains is allowed. Wastewater must be desilted before discharging according to water discharge license.

(b)         Site Clearance

Sections 7, 8 and 9

-     Waste

-     Air pollution

-     Noise pollution

(c)         Tree Felling

Sections 6, 7, 8 and 9

-     Waste

-     Air pollution

-     Noise pollution

ND/2019/04

(a)         Sheet piling

Bridge A2, A3,

Portion K

-     Air, Noise, Waste

-              Dusty works should be sprayed with water or stockpile should be covered by tarpaulin properly.

-              Plants should have maintenance to prevent dark smoke and oil leakage. Idle plant should be turned off.

-              Drip tray should be provided for all chemical and stationary plants.

-              No construction works shall be carried out in restricted hours (7:00 pm to 7:00 am) unless CNP is granted.

-              Waste should be sorted and disposed according to Waste Management Plan.

-              No direct discharge of wastewater into storm water drains is allowed. Wastewater must be desilted before discharging according to water discharge license.

(b)         Bored piling

Bridge A1, A2, A3

-     Air, Noise, Water, Waste

(c)         Predrill

Bridge A1

-     Air, Noise, Water, Waste

(d)        Excavation & ELS

Portion H, K

Bridge A2, A3, F

-     Air, Noise, Waste

(e)         Site clearance

Portion K

-     Air, Noise, Waste

(f)          Tree felling and transplant

Felling:

Portion D, F, C

-     Air, Noise, Waste

ND/2019/05

(a)         Pre-drilling

B2-03-P3, P5, P6, E3-04b, E3-05M

and E4-01

-     Construction Dust Impact

-     Noise Impact

-     Water Quality Impact (Construction Phase)

-     Waste Management  (Construction Waste)

-     Landscape and Visual

-     Cultural Heritage

-              Regular watering on exposed worksites and haul road.

-              Stockpiling area should be provided with covers and water spraying system.

-              Only well maintained plant to be operated on site.

-              plant known to emit noise strongly in one direction, where possible, be orientated so that the noise is directed away from nearby NSRs.

-              mobile plant to be sited as far away from NSRs as possible practicable.

-              All open stockpiles of construction materials of more than 50m3 to be cove red with tarpaulin.

-              Manholes to be adequately covered and temporarily sealed so as to prevent silt, construction materials or debris being washed into the drainage system.

-              All vehicles and plant to be cleaned before leaving a construction site to ensure no earth, mud, debris and the like is deposited by them on roads.

-              Segregate and store different types of waste in different containers, skip or stockpiles to enhance reuse or recycling of materials and their proper disposal.

-              Sort out demolition debris and ex cavated materials from demolition works to recover reusable/recyclable portions.

-              Provide training to workers on appropriate waste management procedures, including waste reduction, reuse and recycling.

-              To adopt other good site practice, such as arrangements for collection and effective disposal to an appropriate facility, of all wastes generated at the site and regular cleaning and maintenance programme for drainage.

-              Chemical wastes to be stored in appropriate containers and collected by a licensed chemical waste Contractor. Chemical wastes (e.g. spent lubricant oil) should be recycled at an appropriate facility as far as possible, while the chemical waste that ca nnot be recycled should be disposed of at either the Chemical Waste Treatment Centre, or another licensed facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

-              Conducting Construction Vibration Monitoring

-              Tree Protection & Preservation Exiting trees to be retained within the Project Site should be carefully protected during construction. In particular OVTs will be preserved according to ETWB Technical Circular (Works) No. 29/2004.

-              Tree Transplantation Trees unavoidably affected by the Project works should be transplanted where practical. Trees should be transplanted straight to their final receptor site and not held in a temporary nursery as far as possible.

-              Erect 2m high dull green site boundary fence.

(b)         Bored piling (Rotary type / RCD)

B1, B2 & C1(Portion II) and D2-01.

(c)         Piling

E3-04b, E3-05M and E4-01

(d)        Erection of steel bridge

HKY FB (East)

(e)         ELS & Pile Cap Construction

B1-01m, B1-02ab, C1-01b, C1-02b, C1-03ab, C2-01, C2-02, C2-03a, C2-04a, C3-01a, C3-02, D1-02 and E2-01, E2-03

(f)          Base slab Construction

NB109

(g)         Duct Works and backfilling

Portion 13, Portion 17 and 18, TWSR (West),TWSR(East)

(h)         Pier/Pier head Construction

B1-02ab, C1-01ab, C1-02ab, C1-03ab, C1-04ab, C2-01, C2-02, D1-02, E1-04 & E2-01, E3-02, E2-03, D2-02, D2-03

(i)          Road Construction

Venton Area

(j)          Segment Fabrication

bridge C2 & C3 & D1 & E1

(k)         Segments Erection

bridges D1 and E1

(l)          SOP & Segment construction (precast & in-situ cast in sype)

C4-04, E3-03, E2-02

ND/2019/06

Site Clearnace

Portions 4

N/A

N/A

ND/2019/07

(a)         Erection of site hoarding

Portions 3, 4

-     Construction Dust Impact

-     Noise Impact

-     Water Quality Impact (Construction Phase)

-     Waste Management (Construction Waste)

-     Landscape and Visual

-              Regular watering on exposed worksites and haul road.

-              Stockpiling area should be provided with covers and water spraying system.

-              Only well-maintained plant to be operated on-site.

-              plant known to emit noise strongly in one direction, where possible, be orientated so that the noise is directed away from nearby NSRs.

-              mobile plant to be sited as far away from NSRs as possible practicable.

-              All open stockpiles of construction materials of more than 50m3 to be covered with tarpaulin.

-              Manholes to be adequately covered and temporarily sealed so as to prevent silt, construction materials or debris being washed into the drainage system.

-              All vehicles and plant to be cleaned before leaving a construction site to ensure no earth, mud, debris and the like is deposited by them on roads.

-              Segregate and store different types of waste in different containers, skip or stockpiles to enhance reuse or recycling of materials and their proper disposal.

-              Sort out demolition debris and excavated materials from demolition works to recover reusable/recyclable portions.

-              Provide training to workers on appropriate waste management procedures, including waste reduction, reuse and recycling.

-              To adopt other good site practice, such as arrangements for collection and effective disposal to an appropriate facility, of all wastes generated at the site and regular cleaning and maintenance programme for drainage.

-              Chemical wastes to be stored in appropriate containers and collected by a licensed chemical waste Contractor. Chemical wastes (e.g. spent lubricant oil) should be recycled at an appropriate facility as far as possible, while the chemical waste that cannot be recycled should be disposed of at either the Chemical Waste Treatment Centre, or another licensed facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

-              Tree Protection & Preservation – Exiting trees to be retained within the Project Site should be carefully protected during construction. In particular OVTs will be preserved according to ETWB Technical Circular (Works) No. 29/2004.

-              Tree Transplantation – Trees unavoidably affected by the Project works should be transplanted where practical. Trees should be transplanted straight to their final receptor site and not held in a temporary nursery as far as possible.

-              Erect 2m high dull green site boundary fence.

-              Light Control – Construction day and night time lighting should be controlled to minimize glare impact to adjacent VSRs during the Construction phase.

(b)         C&D waste disposal

Portion 1, 2, 4, 5

(c)         Construction of box culvert

Portions 2

(d)        Filling works

Portions 1, 2, 4

(e)         Construction of site haul road

Portions 4

(f)          Drainage Works

Portion 1, 3, 4, 5

(g)         Sewerage works

Portion 1, 3, 4, 5

(h)         Construction of Noise Barrier

Portion 5

(i)          Waterworks

Portion 1