10                IMPLEMENTATION SCHEDULE OF THE PROPOSED MITIGATION MEASURES

S3.7.1

Dust mitigation measures stipulated in the Air Pollution Control (Construction Dust) Regulation shall be incorporated to control dust emission.  Notice shall be given to authority prior to commencing of work

Work sites / during construction period

Contractor

Ö

Air Pollution Control (Construction Dust) Regulation

S3.7.5 & 3.7.8

Exposed area at Stage I/II & IV of inlet pumping stations, sludge digestion tank outlet chambers should be covered, with the foul air drawn through deodorization units and discharged after treatment. The grit removal & flume channel at Stage I/II inlet works and the grit removal at Stage IV inlet works should be covered. 

TPSTW / during design and operation stage

DSD / Contractor

Ö

Ö

S3.7.6

Weir launders of the Stage I/II and Stage IV primary sedimentation tanks should be covered to control odour emission from the Stage I/II and Stage IV. Chemical should also be added to the sewage at Tai Yuen Sewage Pumping Station No.4 for the control of odour at Stage IV inlet pumping station, screen house and primary sedimentation tanks.

TPSTW / during design and operation stage

DSD / Contractor

Ö

Ö

S3.7.7

The sludge gravity thickeners, sludge consolidation tanks, screening unit (next to dewatering house), exposed area of wet well of Stage I/II returned activated sludge pumping station and wet well of Stage I/II sludge pumping station should be enclosed to ensure no leakage of odorous gas whereas foul air from the sludge gravity thickeners and sludge consolidation tanks would be discharged via deodorizers.

TPSTW / during design and operation stage

DSD

Ö

Ö

S3.7.17

A field test should be conducted to determine the quantity of chemicals to achieve the recommended odour removal efficiency at Stage IV inlet pumping station, Stage IV screening house and Stage IV Primary Sedimentation Tanks

TPSTW / before commissioning of the Stage V of TPSTW

DSD

Ö

S7.7.2

Use of quiet PME

Work sites / During the construction period

Contractor

Ö

EIAO-TM and Noise Control Ordinance

S 7.7.3

Good Site Practice

·        Only well-maintained plant should be operated on-site and plant should be serviced regularly during the construction program;

·        Silencers or mufflers on construction equipment should be utilized and should be properly maintained during the construction program;

·        Mobile plant, if any, should be sited as far from NSRs as possible;

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

·        Plant known to emit noise strongly in one direction should, wherever possible, be orientated so that the noise is directed away from the nearby NSRs; and

·        Material stockpiles and other structures should be effectively utilised, wherever practicable, in screening noise from on-site construction activities.

Work sites / During the construction period

Contractor

Ö

EIAO-TM and Noise Control Ordinance

S4.8.1

The practices outlined in ProPECC PN 1/94 Construction Site Drainage should be adopted to minimize the potential water quality impacts from construction site runoff and various construction activities. The recommendation to install perimeter drains to collect site runoff and to properly treat the runoff by settlement tank/treatment system shall apply to all sites including those for mainlaying works. Minimum distances of 100 m should be maintained between the discharge points of construction site runoff and the existing WSD saltwater intake at Tai Po.

TPSTW / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.2

A discharge licence needs to be applied from EPD for discharging effluent from the construction site. The discharge quality is required to meet the requirements specified in the discharge licence. All the runoff and wastewater generated from the works areas should be treated so that it satisfies with all the standards listed in the TM.  Reuse and recycling of the treated effluent can minimize water consumption and reduce the effluent discharge volume. The beneficial uses of the treated effluent may include dust suppression, wheel washing and general cleaning. Monitoring of the discharge quality of treated effluent should be part of the Environmental Monitoring and Audit (EM&A) programme. Detailed effluent sampling programme for water quality control during construction phase should be submitted to EPD, AFCD and WSD for approval prior to commencement of the construction works.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.3

The construction programme should be properly planned to minimize soil excavation, if any, in rainy seasons. This prevents soil erosion from exposed soil surfaces. Any exposed soil surfaces should also be properly protected to minimize dust emission. In areas where a large amount of exposed soils exist, earth bunds or sand bags should be provided. Exposed stockpiles should be covered with tarpaulin or impervious sheets at all time. The stockpiles of materials should be placed in the locations away from any stream courses so as to avoid releasing materials into the water bodies. Final surfaces of earthworks should be compacted and protected by permanent work. It is suggested that haul roads should be paved with concrete and the temporary access roads are protected using crushed stone or gravel, wherever practicable. Wheel washing facilities should be provided at all site exits to ensure that earth, mud and debris would not be carried out of the works areas by vehicles.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.4

Good site practices should be adopted to clean the rubbish and litter on the construction sites so as to prevent the rubbish and litter from dropping into the nearby environment. It is recommended to clean the construction sites on a regular basis.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.5

It is recommended to provide sufficient chemical toilets in the works areas. The toilet facilities should not be less than 30 m from any watercourse. A licensed waste collector should be deployed to clean the chemical toilets on a regular basis. The construction workers can also make use of the existing toilet facilities within the TPSTW as necessary.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.6

Notices should be posted at conspicuous locations to remind the workers not to discharge any sewage or wastewater into the nearby environment during the construction phase of the project. Implementation of environmental audit on the construction site can provide an effective control of any malpractices and can achieve continual improvement of environmental performance on site.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.7

It is required to register as a chemical waste producer if chemical wastes would be produced from the construction activities. The Waste Disposal Ordinance (Cap 354) and its subsidiary regulations in particular the Waste Disposal (Chemical Waste) (General) Regulation should be observed and complied with for control of chemical wastes.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.8

Any service shop and minor maintenance facilities should be located on hard standings within a bunded area, and sumps and oil interceptors should be provided. Maintenance of vehicles and equipment involving activities with potential for leakage and spillage should only be undertaken within the areas appropriately equipped to control these discharges.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.9

Disposal of chemical wastes should be carried out in compliance with the Waste Disposal Ordinance. The Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes published under the Waste Disposal Ordinance details the requirements to deal with chemical wastes. General requirements are given as follows:

·   Suitable containers should be used to hold the chemical wastes to avoid leakage or spillage during storage, handling and transport.

·   Chemical waste containers should be suitably labelled to notify and warn the personnel who are handling the wastes to avoid accidents.

·  Storage area should be selected at a safe location on site and adequate space should be allocated to the storage area.

Work site / During the construction period

Contractor

Ö

ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S4.8.10

Silt curtains should be installed at the Shatin and Tai Po Seawater Intakes. Relevant government departments including EPD and WSD should be informed of the maintenance

TPSTW/During the  maintenance of THEES tunnel

DSD

Ö

S4.8.11

Dual power supply or ring main supply from CLP should be provided for the Project to avoid any loss of electrical supply. In addition, standby facilities for the main treatment units, standby parts / accessories to the equipment should also be provided in order to minimize the chance of emergency discharge.

TPSTW/ Before commencement of the Project

DSD

Ö

Ö

WPCO

S4.8.10

S4.8.12

Shutdown of the THEES, if unavoidable, should be shortened as far as possible.  The relevant procedures established in the contingency plan as attached in Appendix 4.5 of the EIA report should be properly followed.

TPSTW/ During operation period

DSD

Ö

WPCO

S4.8.13

Dye test is recommended for detection of pipe leakage

Submarine pipeline at Tolo Harbour/ During operation period

DSD

Ö

WPCO

S4.10.1

Effluent monitoring is recommended to ensure the effectiveness of the proposed treatment process. Details of the monitoring requirements are specified in the EM&A Manual.

Exit of disinfection facilities/ During operation period

DSD

Ö

WPCO

S4.10.2

A post project monitoring (PPM) programme for Victoria Harbour should be implemented to confirm the predictions of the water quality made in the EIA report. The PPM would consist of one-year baseline monitoring before commissioning and one-year impact monitoring after commissioning of the Project. The extent of PPM programme is subject to the prevailing environmental conditions at the time before commissioning of the Project. A more detailed description of the PPM requirements is given in the standalone EM&A Manual.

Victoria Harbour/During operation period

DSD

Ö

WPCO

S4.10.3

A PPM programme will be also implemented in the Tolo Harbour during the operational phase.  The PPM would involve water quality monitoring at the Tai Po and Sha Tin seawater intake during the first wet season (June to August) after full commissioning of the Project.  Marine water quality parameters including SS and NH₃-N should be monitored. The water quality monitoring frequency shall be twice per month and should
cover the effects of different tidal status (at least one for high tide and one
for low tide) for each seawater intakewould follow the future PPM for Victoria Harbour.

Tolo Harbour/During operation period

DSD

Ö

WPCO

S4.8.10S4.10.4

Marine water quality monitoring should be carried out under emergency condition or during maintenance of the THEES tunnel to verify the findings of the water quality modelling. It is recommended that the maintenance of the THEES tunnel, if unavoidable, should be conducted during winter season or low flow periods and to avoid the “blooming” season of algae (normally from April to June) if practicable. Details of the monitoring requirements are specified in the EM&A Manual.

Tolo Harbour / During emergency or THEES maintenance discharges

DSD

Ö

Ö

WPCO

S5.5.2

S5.5.3

Good Site Practices and Waste Reduction Measures

Good site practices during the construction activities include:

·         Nomination of an approved personnel, 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.

·         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 shall be prepared and this WMP shall be submitted to the Engineer for approval. One may make reference to ETWB TCW No. 15/2003 for details.

·         In order to monitor the disposal of C&D materials at landfills and public filling areas, and to control fly tipping, a trip-ticket system shall be included as one of the contractual requirements and implemented by an Environmental Team undertaking the Environmental Monitoring and Audit work.  One may make reference to WBTC No. 21/2002 for details.

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

Work sites / During the construction period

Contractor

Ö

Waste Disposal Ordinance (Cap.54);

WBTC No.21/2002; ETWB TCW No. 15/2003; ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S5.5.4

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:

·         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.

·         Maximise the use of reusable steel formwork to reduce the amount of C&D material.

·         Prior to disposal of C&D waste, it is recommended that wood, steel and other metals shall be separated for re-use and / or recycling to minimise the quantity of waste to be disposed of to landfill.

·         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.

·         Minimise over ordering of concrete, mortars and cement grout by doing careful check before ordering

Work sites / During planning & design stage, and construction stage

Contractor

Ö

Ö

Waste Disposal Ordinance (Cap.54);

WBTC No.21/2002; ETWB TCW No. 15/2003; ProPECC PN 1/94; WPCO, Waste Disposal Ordinance

S5.5.6

General Refuse

General refuse shall be stored in enclosed bins or compaction units separate from C&D material.  A reputable waste collector shall 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.

Work sites / During the construction period

Contractor

Ö

Public Health and Municipal Services Ordinance (Cap. 132

S5.5.7

Construction & Demolition (C&D) Material

C&D material generated from the site formation and demolition works shall be sorted on-site into inert C&D material (i.e. public fill) and C&D waste.   

In order to minimise the impact resulting from collection and transportation of C&D material for off-site disposal, the excavated material comprising fill material shall be reused on-site as backfilling material as far as practicable.  C&D waste, such as wood, 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 within the site for temporary stockpiling of C&D material and to facilitate the sorting process.

Work sites / During the construction period

Contractor

Ö

WBTC No. 4/98, 21/2002, 25/99, 12/2000

ETWB TCW No. 15/2003

S5.5.8

Bentonite Slurry

Bentonite slurries used in construction works should be reconditioned and reused wherever practicable.  Residual used bentonite slurry should be disposed of from the site as soon as possible.  The Contractor should explore alternative disposal outlets for the residual used bentonite slurry and disposal at landfill should be the last resort.

Work sites / During the construction period

Contractor

Ö

Clause 8.56 of the General Specification for Civil Engineering Works

S5.5.9

Chemical Waste

For the disposal of spent UV lamps, the STW operator would be required to register with the EPD as a Chemical Waste Producer and to follow the requirements stated in the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes.  A chemical waste producer must engage a licensed waste collector to transport and dispose of the chemical wastes in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

TPSTW / During operation period

Contractor

Ö

Waste Disposal (Chemical Waste) (General) Regulation; Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes

S6.6.3

All personnel who work on the site and all visitors to the site should be aware of the possibility of ignition of gas in the vicinity of excavations. Safety notices should be displayed at prominent position around the site. Adequate fire extinguisher equipment and fire resistant clothing should be made available on site

Work sites within 250m consultation zone/ During the construction period

Contractor

Ö

EIAO-TM, Code of Practice on Safety and Health at Work in Confined Space, ProPECC PN3/96 & EPD/TR8/97

S6.6.4

Service runs within the consultation zone should be designated as “special routes” and utilities companies should be informed of this and should implement precautionary measures

Work sites within 250m consultation zone/ During the construction period

Contractor, Utilities company

Ö

Code of Practice on Safety and Health at Work in Confined Space

S6.6.5

Precautionary measures to minimize landfill gas hazard during excavation:

·         No smoking or burning shall be allowed

·         No worker shall work alone at any time in the confined space or any excavation trenches

·         Construction equipment shall be equipped with a vertical exhaust at least 0.6 m above ground level and /or with a park arrestors

·         Electrical motors and electrical extension cords shall be explosive-proof or intrinsically safe

·         Permit to Work procedures to be adopted for welding, flame cutting or other hot works in trenches or confined spaces

·         Forced ventilation if working in a trench deeper than 1 m

·         Close all valves immediately after piping assembly or conduiting construction. For the large diameter pipes, pipe end shall be capped on one side. Forced ventilation shall also be provided before commissioning of the pipeline and staff entering and working in it.

·         Routine monitoring shall be conducted in all excavations to ensure the works area to be free of landfill gas before any man enters the area.

·         Landfill gas precautionary measures involved with excavation and piping works shall be included in the Safety Plan

Work sites within 250m consultation zone/ During the construction period

Contractor

Ö

Landfill Gas Hazard Assessment Guidance Note (EPD/TR8/97)

S6.6.6

Monitoring shall be conducted at the cracks on the ground floor during ground-works construction

Work sites within 250m consultation zone/ During the construction period

Contractor

Ö

Landfill Gas Hazard Assessment Guidance Note (EPD/TR8/97)

S6.6.7

Where there are any temporary site offices, or any other buildings which have enclosed spaces with the capacity to accumulate landfill gas, then they should either:

·         be located on an area which has been proven t be free of landfill gas (by survey with portable gas detectors) and monitored manually by the Safety Officer or an approved wand appropriately qualified person to ensure that hazardous concentration of landfill gas does not occur; or

·         be raised clear of the ground. If buildings are raised clear of the ground, a minimum, clear separation (as measured from the highest point on the ground surface to the underside of lowest floor joist) should be 500mm

Work sites within 250m consultation zone/ During the construction period

Contractor

Ö

Landfill Gas Hazard Assessment Guidance Note (EPD/TR8/97)

S6.6.8

Such offices or buildings should be provided with some kinds of control of gas by mechanical means e.g. forced ventilation using fans or blowers

Work sites within 250m consultation zone/ During the construction period

Contractor

Ö

Landfill Gas Hazard Assessment Guidance Note (EPD/TR8/97)

S6.6.9

When service voids, manholes or inspection chambers within the proposed site are entered for maintenance, monitoring and a checklist system of safety requirements should be performed before entry in accordance with Code of Practice on Safety and Health at Work in Confined Spaces.

Area of TPSTW within 250m consultation zone/ During the operational period

DSD, Contractor

Ö

Code of Practice on Safety and Health at Work in Confined Spaces

S6.6.10

For newly built permanent structures, gas-resistant polymeric membranes shall be incorporated into floor or wall construction to act as a continuous sealed layer for the structure. In addition, forced ventilation shall be installed in such rooms or buildings. Gas detection systems should also be proposed where there is an organisation involved in the long-term or frequently use of the development in order to monitor internal spaces inside buildings.

Area of TPSTW within 250m consultation zone/ During the operational period

DSD

Ö

Ö

Code of Practice on Safety and Health at Work in Confined Spaces

S6.6.11

Forced ventilation should be used if methane of more than 0.5 % (by volume) in the internal atmosphere (e.g. in service voids, manholes, inspection chambers or rooms as mentioned above) is detected.

Area of TPSTW within 250m consultation zone/ During the operational period

DSD

Ö

Code of Practice on Safety and Health at Work in Confined Spaces

S6.6.12

No person should enter or remain in any confined spaces or trenches where the carbon dioxide concentration exceeds 1.5 % (by volume).

Area of TPSTW within 250m consultation zone/ During the operational period

DSD

Ö

Code of Practice on Safety and Health at Work in Confined Spaces

S6.6.13

Oxygen concentration should be monitored and no person shall enter or remain in any confined spaces or trenches where the oxygen content of air has fallen below 18 % by volume.

Area of TPSTW within 250m consultation zone/ During the operational period

DSD

Ö

Code of Practice on Safety and Health at Work in Confined Spaces

S6.6.14

All the access to these confined spaces should be restricted only to authorised personnel who should be aware of the LFG hazard.  No member of general public should be permitted or allowed to access these confined spaces, manholes or inspection chambers.

Area of TPSTW within 250m consultation zone/ During the operational period

DSD

Ö

Code of Practice on Safety and Health at Work in Confined Spaces