13                IMPLEMENTATION SCHEDULE OF THE PROPOSED MITIGATION MEASURES

 

Table 13.1       Implementation Schedule for Air Quality Control

EIA Ref 

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction Phase

S3.6.1

No adverse air quality impacts at the ASRs are expected during the construction of this DP.  However, the operated dredgers and equipments should be regularly maintained to minimise emissions during construction phase.

Work site / during construction

Contractor

 

Ö

 

 

EIAO-TM

* Des - Design, C - Construction, O – Operation, and Dec - Decommissioning
Table 13.2       Implementation Schedule for Noise Control

EIA Ref 

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction Phase

 

 

 

 

 

 

 

S4.9.2

Good Site Practice:

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

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

Ÿ          Mobile plant, if any, shall be sited as far away from NSRs as possible.

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

Ÿ          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.

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

 

Work Sites / During Construction

Contractor

 

Ö

 

 

EIAO-TM, NCO

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

S4.8.3 – S4.8.5

Use of quiet powered mechanical equipment for the following tasks:

·          Submarine pipelines (marine section)

 

Use of quiet powered mechanical equipment and movable noise barrier for the following tasks:

·          Installation of a new pipeline (land section)

 

 

Work Sites / During Construction

Contractor

 

Ö

 

 

EIAO-TM, NCO

* Des - Design, C - Construction, O – Operation, and Dec - Decommissioning


Table 13.3       Implementation Schedule for Water Quality Control

EIA Ref

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction Phase

 

 

 

 

 

 

 

S5.8

Dredging for construction of the proposed sewage outfall shall be carried out by closed grab dredger.  The corresponding dredging rates shall not be more than 1,500 m3 per day.

Work site / During the construction period

Contractor

 

Ö

 

 

EIAO-TM, WPCO

S5.8, Figure 5.3

Silt screens shall be applied to seawater intakes at interim WDII construction stages as stated below:

Interim Construction Stage

Location of Applications

Scenario 2B in late 2009/2010 with concurrent dredging activities at Sewage Pipelines Zone and TCBR.

WSD saltwater intakes at Sheung Wan, Wan Chai

Cooling water intakes for Queensway Government Offices, Excelsior Hotel, World Trade Centre and Windsor House.

Work site / During the construction period

Contractor

 

Ö

 

 

EIAO-TM, WPCO

 

 

 

 

 

 

 

 

 

S5.8

Other mitigation measures include:

·       mechanical grabs, if used, shall be designed and maintained to avoid spillage and sealed tightly while being lifted.  For dredging of any contaminated mud, closed watertight grabs must be used;

·       all vessels shall be sized so that adequate clearance is maintained between vessels and the seabed in all tide conditions, to ensure that undue turbidity is not generated by turbulence from vessel movement or propeller wash;

·       all hopper barges and dredgers shall be fitted with tight fitting seals to their bottom openings to prevent leakage of material;

Work site / During the construction period

Contractor

 

Ö

 

 

ProPECC PN 1/94;

WPCO (TM-DSS)

 

·       construction activities shall not cause foam, oil, grease, scum, litter or other objectionable matter to be present on the water within the site or dumping grounds;

 

 

 

 

 

 

 

 

·       loading of barges and hoppers shall be controlled to prevent splashing of dredged material into the surrounding water.  Barges or hoppers shall not be filled to a level that will cause the overflow of materials or polluted water during loading or transportation; and

 

 

 

 

 

 

 

S5.8

Silt screens are recommended to be deployed at the seawater intakes during the marine works period. Installation of silt screens at the seawater intake points may cause a potential for accumulation and trapping of pollutants, floating debris and refuse behind the silt screens and may lead to potential water quality deterioration at the seawater intake points. Major sources of pollutants and floating refuse include the runoff and storm water discharges from the nearby coastal areas.  As a mitigation measure to avoid the pollutant and refuse entrapment problems and to ensure that the impact monitoring results are representative, regular maintenance of the silt screens and refuse collection shall be performed at the monitoring stations at regular intervals on a daily basis.  The Contractor shall be responsible for keeping the water behind the silt screen free from floating rubbish and debris during the impact monitoring period.

Work site / During the construction period

Contractor

 

Ö

 

 

EIAO-TM, WPCO

S5.8

The mitigation measures for construction runoff and drainage as listed below should be implemented where applicable.

Construction Runoff and Drainage

Exposed soil areas should be minimised to reduce the potential for increased siltation, contamination of runoff, and erosion.  Construction runoff related impacts associated with the above ground construction activities can be readily controlled through the use of sediment traps and adequate maintenance of drainage systems to prevent flooding and overflow.

Construction site should be provided with adequately designed perimeter channel and pre-treatment facilities and proper maintenance.  The boundaries of critical areas of earthworks should be marked and surrounded by dykes or embankments for flood protection.  Temporary ditches should be provided to facilitate runoff discharge into the appropriate watercourses, via a silt retention pond.  Permanent drainage channels should incorporate sediment basins or traps and baffles to enhance deposition rates.  The design of efficient silt removal facilities should be based on the guidelines in Appendix A1 of ProPECC PN 1/94.

Work site / During the construction period

Contractor

 

Ö

 

 

ProPECC PN 1/94;

WPCO (TM-DSS)

 

Ideally, construction works should be programmed to minimise surface excavation works during the rainy season (April to September).  All exposed earth areas should be completed as soon as possible after earthworks have been completed, or alternatively, within 14 days of the cessation of earthworks where practicable.  If excavation of soil cannot be avoided during the rainy season, or at any time of year when rainstorms are likely, exposed slope surfaces should be covered by tarpaulin or other means.

 

 

 

 

 

 

 

 

A sediment tank constructed from pre-formed individual cells of approximately 6 ‑ 8 m3 capacity can be used for settling ground water prior to disposal;

 

 

 

 

 

 

 

 

Open stockpiles of construction materials (for examples, aggregates, sand and fill material) of more than 50 m3 should be covered with tarpaulin or similar fabric during rainstorms.  Measures should be taken to prevent the washing away of construction materials, soil, silt or debris into any drainage system.

 

 

 

 

 

 

 

S5.8

Construction Runoff and Drainage (continued)

Manholes (including newly constructed ones) should always be adequately covered and temporarily sealed so as to prevent silt, construction materials or debris being washed into the drainage system and storm runoff being directed into foul sewers;

Precautions to be taken at any time of year when rainstorms are likely, actions to be taken when a rainstorm is imminent or forecast, and actions to be taken during or after rainstorms are summarised in Appendix A2 of ProPECC PN 1/94.  Particular attention should be paid to the control of silty surface runoff during storm events;

Oil interceptors should be provided in the drainage system and regularly cleaned to prevent the release of oils and grease into the storm water drainage system after accidental spillages.  The interceptor should have a bypass to prevent flushing during periods of heavy rain.

 

Work site / During the construction period

Contractor

 

Ö

 

 

ProPECC PN 1/94;

WPCO (TM-DSS)

 

All vehicles and plant should be cleaned before leaving a construction site to ensure no earth, mud, debris and the like is deposited by them on roads.  An adequately designed and located wheel washing bay should be provided at every site exit, and wash-water should have sand and silt settled out and removed at least on a weekly basis to ensure the continued efficiency of the process.  The section of access road leading to, and exiting from, the wheel-wash bay to the public road should be paved with sufficient backfall toward the wheel-wash bay to prevent vehicle tracking of soil and silty water to public roads and drains.

 

 

 

 

 

 

 

 

S5.8

Construction Runoff and Drainage (Continued)

It is recommended that on-site drainage system should be installed prior to the commencement of other construction activities.  Sediment traps should be installed in order to minimise the sediment loading of the effluent prior to discharge into foul sewers.  There shall be no direct discharge of effluent from the site into the sea.

All temporary and permanent drainage pipes and culverts provided to facilitate runoff discharge shall be adequately designed for the controlled release of storm flows.  All sediment control measures shall be regularly inspected and maintained to ensure proper and efficient operation at all times and particularly following rain storms.  The temporarily diverted drainage shall be reinstated to its original condition when the construction work is finished or the temporary diversion is no longer required.

All fuel tanks and store areas shall be provided with locks and be sited on sealed areas, within bunds of a capacity equal to 110% of the storage capacity.

 

Work site / During the construction period

Contractor

 

Ö

 

 

ProPECC PN 1/94;

WPCO (TM-DSS)

S5.8

Sewage from Construction Work Force

 

Construction work force sewage discharges on site shall be connected to the existing trunk sewer or sewage treatment facilities.  The construction sewage shall be handled by portable chemical toilets prior to the commission of the on-site sewer system.  Appropriate numbers of portable toilets shall be provided by a licensed contractor to serve the large number of construction workers over the construction site.  The Contractor shall also be responsible for waste disposal and maintenance practices.

Work site / During the construction period

Contractor

 

Ö

 

 

ProPECC PN 1/94; WPCO (TM-DSS)

S5.8

Floating Debris and Refuse

 

Collection and removal of floating refuse shall be performed at regular intervals on a daily basis.  The contractor shall be responsible for keeping the water within the site boundary and the neighbouring water free from rubbish.

 

Work site and adjacent water / During the construction period.

Contractor

 

Ö

 

 

WPCO

S5.8

Storm Water Discharges

 

Minimum distances of 100 m shall be maintained between the existing or planned stormwater discharges and the existing or planned WSD flushing water intakes.

 

Work site and adjacent water / During the design and construction period.

Contractor

Ö

Ö

 

 

WPCO

* Des - Design, C - Construction, O – Operation, and Dec - Decommissioning


Table 13.4       Implementation Schedule for Waste Management

EIA Ref  

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction Phase

 

 

 

 

 

 

 

 

 

S6.7.2 

 

 

 

 

 

 

Marine Sediments

 

The dredged marine sediments would be loaded onto barges, transported to and disposed of at the designated disposal sites at South of Cheung Chau, East of Ninepin, East of Tung Lung Chau, South of Tsing Yi and East of Sha Chau to be allocated by the MFC depending on their level of contamination or at other disposal sites after consultation with the MFC and EPD. In accordance with the ETWB TCW No. 34/2002, the contaminated material must be dredged and transported with great care.  The mitigation measures recommended in Section 5 of the EIA Report shall be incorporated. The dredged contaminated sediment must be effectively isolated from the environment upon final disposal and shall be disposed of at the Type 2 confined marine disposal contaminated mud pit.

 

 

 

Work site / During the construction period

 

 

 

Contractor

 

 

 

Ö

 

 

 

 

ETWB TCW No. 34/2002

S6.7.3 

 

It will be the responsibility of the Contractor to satisfy the appropriate authorities that the contamination levels of the marine sediment to be dredged have been analysed and recorded.  According to the ETWB TCW No. 34/2002, this will involve the submission of a formal Sediment Quality Report to the DEP, at least 3 months prior to the dredging contract being tendered

 

 

 

 

 

 

 

 

 

S6.7.4

 

During transportation and disposal of the dredged marine sediments requiring Type 1 and Type 2 disposal, the following measures shall be taken to minimise potential impacts on water quality:

 

 

 

 

 

 

 

 

 

·         Bottom opening of barges shall be fitted with tight fitting seals to prevent leakage of material.  Excess material shall be cleaned from the decks and exposed fittings of barges and hopper dredgers before the vessel is moved.

 

 

 

 

 

 

 

 

 

·          Monitoring of the barge loading shall be conducted to ensure that loss of material does not take place during transportation.  Transport barges or vessels shall be equipped with automatic self-monitoring devices as specified by the DEP.

·          Barges or hopper barges shall not be filled to a level that would cause the overflow of materials or sediment laden water during loading or transportation.

 

 

 

 

 

 

 

 

S6.7.5

Good Site Practices

Recommendations for good site practices during the construction activities include:

·         nomination of an approved person, such as a site manager, to be responsible for good site practices, arrangements for collection and effective disposal to an appropriate facility, of all wastes generated at the site;

 

Work site / During the construction period

Contractor

 

Ö

 

 

Waste Disposal Ordinance (Cap.354)

 

·         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;

·         regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors; and

·         a recording system for the amount of wastes generated, recycled and disposed of (including the disposal sites).

 

 

 

 

 

 

 

 

S6.7.6

Waste Reduction Measures

 

Waste reduction is best achieved at the planning and design stage, as well as by ensuring the implementation of good site practices.  Recommendations to achieve waste reduction include:

·                     Sort C&D waste from demolition of the existing structures to recover recyclable portions such as metals.

·                     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.

 

Work site / During planning and design stage, and construction stage

Contractor

Ö

Ö

 

 

 

 

·                     Encourage collection of aluminium cans, PET bottles and paper by providing separate labelled bins to enable these wastes to be segregated from other general refuse generated by the work force.

 

 

 

 

 

 

 

 

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

 

 

 

 

 

 

 

 

·                     Use of reusable non-timber 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.

 

 

 

 

 

 

 

 

S6.7.8

 

 

 

 

 

 

 

 

General Refuse

 

General refuse shall be stored in enclosed bins or compaction units separate from C&D material.  A licensed waste collector shall be employed by the contractor to remove general refuse from the site, separately from C&D material. 

 

A collection area shall be provided where wastes can be stored and loaded prior to removal from site.  An enclosed and covered area is recommended to reduce the occurrence of 'wind blow' light material. 

 

Work site / During the construction period

Contractor

 

Ö

 

 

Public Health and Municipal Services Ordinance (Cap. 132)

 

 

 

 

S6.7.9

Chemical Wastes

 

After use, chemical wastes (for example, cleaning fluids, solvents, lubrication oil and fuel) shall be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes.  Spent chemicals shall be collected by a licensed collector for disposal at the CWTF or other licensed facility in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

 

Work site / During the construction period

Contractor

 

Ö

 

 

Waste Disposal (Chemical Waste) (General) Regulation

 

Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes

S6.7.10

 

Construction and Demolition Material

 

C&D material shall be sorted on-site into inert C&D material (that is, public fill) and C&D waste. All the suitable inert C&D material shall be broken down to 250 mm in size for reuse as public fill in the WDII reclamation.  C&D waste, such as wood, glass, plastic, steel and other metals shall be reused or recycled and, as a last resort, disposed of to landfill.  A suitable area shall be designated to facilitate the sorting process and a temporary stockpiling area will be required for the separated materials.

 

Work site / During the construction period

Contractor

 

Ö

 

 

ETWB TCW No. 33/2002, 31/2004, 19/2005

S6.7.11

In order to monitor the disposal of public fill and C&D waste at public filling facilities and landfills, respectively, and to control fly tipping, a trip-ticket system shall be included as one of the contractual requirements and implemented by the Environmental Team undertaking the environmental monitoring and audit work.  An Independent Environment Checker shall be responsible for auditing the results of the system.

 

Work site / During the construction period

Contractor and Independent Environmental Checker

 

Ö

 

 

ETWB TCW No. 31/2004

* Des - Design, C - Construction, O – Operation, and Dec - Decommissioning

 


Table 13.5       Implementation Schedule for Land Contamination

EIA Ref  

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction and Operation Phase

S.7.1.1

·       As no potential contaminative land uses were identified within the Study Area, adverse land contamination impacts associated with the construction and operation of the Project is not expected.  As such, environmental protection and mitigation measures are considered not necessary.

-

-

 

 

 

 

-

* Des - Design, C - Construction, O – Operation, and Dec - Decommissioning

 


Table 13.6       Implementation Schedule for Marine Ecology

EIA Ref

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction & Operation Phases

 

 

 

 

 

 

 

S.9.7.1

As no adverse ecological impact on marine habitats and associated wildlife is predicted, no necessary mitigation measure specific for marine ecology is considered as required in this assessment.  The mitigation measures recommended in the water quality impact assessment to control water quality would also serve to protect marine ecological resources from indirect impacts and ensure no adverse impact on marine life would be resulted from this designated project.

-

-

 

 

 

 

-

*Des - Design, C - Construction, O – Operation, and Dec - Decommissioning

 


Table 13.7       Implementation Schedule for Landscape and Visual

EIA Ref  

Environmental Protection Measures / Mitigation Measures

Location / Timing

Implementation Agent

Implementation Stages*

Relevant Legislation and Guidelines

Des

C

O

Dec

Construction Phase

 

 

 

 

 

 

 

Refer to EIA-058/2001

Table 10.13

CM2    Minimisation of works areas.

Work site / During Construction Phase

Contractor

 

Ö

 

 

EIAO TM

Refer to EIA-058/2001

Table 10.13

CM3    Erection of decorative hoardings.

Work site / During Construction Phase

Contractor

 

Ö

 

 

EIAO TM

Refer to EIA-058/2001

Table 10.13

CM4    Control night-time lighting.

Work site / During Construction Phase

Contractor

 

Ö

 

 

EIAO TM

Refer to EIA-058/2001

Table 10.13

CM5    Minimisation of disruption to public by effective programming of the works.

Work site / During Construction Phase

Contractor

 

Ö

 

 

EIAO TM

*Des - Design, C - Construction, O – Operation, and Dec - Decommissioning