8.1.1.1 The construction of the Ngong Ping Drainage Improvement Works project will involve a number of activities generating waste which can broadly be classified into distinct categories based on their nature and the options for their disposal. These include:
· Excavated construction and demolition (C&D) materials suitable for public fill (no excavation of sediment would occur in this project);
· C&D waste, including cleared vegetation, which is not suitable for public fill;
· Chemical waste;
· General refuse; and
· Sewage.
8.1.1.2 The Contractor will be responsible to the appropriate handling and disposal of any waste generated and will be required to implement the recommended mitigation measures in order to minimise waste or resolve issues associated with the management of waste. The Contractor should also ensure that all wastes produced during the construction phase are handled, stored and disposed of in accordance with good waste management practices, relevant legislation and waste management guidelines. Wastes generated from the construction activities, such as the construction and demolition (C&D) materials, should be audited at regular intervals to ensure that proper storage, transportation and disposal practices are undertaken. Such audit would ensure the wastes generated to be properly disposed.
8.1.1.3 Large quantities of wastes are not expected to be generated from the operational phase of the drainage improvement works and no adverse environmental impacts would arise with the implementation of good waste management practices. Therefore, an audit programme for the operational phase will not be required.
8.2.1.1 With the proper handling, storage and disposal of wastes arising from the construction works as recommended in the Environmental Mitigation Implementation Schedule in Appendix A of this EM&A Manual, the potential for adverse environmental impacts would be minimised. During site inspections, the Engineer and ET should pay special attention to the issues relating to the waste management and check whether the Contractor has implemented the recommended good site practices and other mitigation measures.
8.2.1.2 The following waste management measures should be implemented by the Contractor during the Construction Phase:
(i)
The
requirements as stipulated in the ETWB TC(W)
No.19/2005 Environmental Management on Construction Sites and the other
relevant guidelines should be included in the Particular Specification for the
Contractor as appropriate.
(ii)
The
future Contractor should be requested to submit a
Waste Management Plan (WMP), which
becomes part of the Environmental Management Plan (EMP), prior to the commencement of
construction work, in accordance with the ETWB TC(W)
No.19/2005 so as to provide an overall framework of waste management and
reduction. The WMP should include:
·
Waste management policy;
·
Record of generated waste;
·
Waste reduction target;
·
Waste reduction programme;
·
Role and responsibility of waste management team;
·
Benefit of waste management;
·
Analysis of waste materials;
·
Reuse, recycling and disposal plans;
·
Transportation process of waste products; and
·
Monitoring and action plan.
(iii)
The
waste management hierarchy below should be strictly followed. This hierarchy should be adopted to evaluate
the waste management options in order to maximise the extent of waste reduction
and cost reduction. The records of
quantities of waste generated, recycled and disposed (locations) should be
properly documented.
(iv)
A
trip-ticket system should be established in accordance with DevB TC(W) No. 6/2010 and Waste Disposal (Charges for Disposal of
Construction Waste) Regulation to monitor the disposal of public fill and solid
wastes at public filling facilities and landfills, and to control
fly-tipping. A trip-ticket system would
be included as one of the contractual requirements for the Contractor to
strictly implement. The Engineer would
also regularly audit the effectiveness of the system.
(v)
A
recording system for the amount of waste generated, recycled and disposed
(locations) should be established. The
future Contractor should also provide proper training to workers regarding the
appropriate concepts of site cleanliness and waste management procedures, e.g.
waste reduction, reuse and recycling all the time.
(vi)
The
CEDD should be timely notified of the estimated volumes of excavated materials
to be generated and the Public Fill Committee should be notified and agreement
sort on the disposal of surplus inert C&D materials. Wherever practicable, C&D materials should
be segregated from other wastes to avoid contamination and to ensure
acceptability at public filling areas or reclamation sites.
(vii)
The
site and surroundings shall be kept tidy and litter free.
(viii)
No
waste shall be burnt on-site.
(ix)
Make
provisions in contract documents to allow and promote the use of recycled
aggregates where appropriate.
(x)
Prohibit
the Contractor to dispose of C&D materials within the proposed site and at
any sensitive locations including
(xi)
Stockpiled
material shall be covered by tarpaulin and /or watered as appropriate to
prevent windblown dust and surface run off.
(xii) Major stockpiled areas shall be sited outside of the country parks area (Works Section 6) and away from stream courses as far as practicable. For the stockpiling area SA4 within the country park area, stockpiling of earthed material shall be minimised and excavated soil from Works Section 6 shall be delivered to the Site Office as soon as possible. Similarly, overnight stockpiling of earthed material along the exposed trench shall be minimised as far as possible and the excavated soil shall be transferred to the designated stockpiling area as soon as possible.
(xiii)
Excavated
material in trucks shall be covered by tarpaulins to reduce the potential for
spillage and dust generation.
(xiv)
Wheel
washing facilities shall be used by all trucks leaving the site to prevent
transfer of mud onto public roads.
(xv)
Standard
formwork or pre-fabrication should be used as far as practicable so as to minimise
the C&D materials arising. The use
of more durable formwork or plastic facing for construction works should also
be considered. The use of wooden
hoardings should be avoided and metal hoarding should be used to facilitate
recycling. Purchasing of construction
materials should be carefully planned in order to avoid over-ordering and
wastage.
(xvi)
The
Contractor should recycle as many C&D materials as possible on-site. The public fill and C&D waste should be
segregated and stored in separate containers or skips to facilitate the reuse
or recycling of materials and proper disposal.
Where practicable, the concrete and masonry should be crushed and used
as fill materials. Steel reinforcement
bar should be collected for use by scrap steel mills. Different areas of the sites should be
considered for segregation and storage activities.
(xvii)
Chemical
waste producers should register with the EPD.
Chemical waste should be handled in accordance with the Code of Practice
on the Packaging, Handling and Storage of Chemical Wastes as follows:
·
suitable for
the substance to be held, resistant to corrosion, maintained in good conditions
and securely closed;
·
Having a capacity of <450L unless the
specifications have been approved by the EPD; and
·
Displaying a label in English and Chinese according
to the instructions prescribed in Schedule 2 of the Regulations.
·
Clearly labelled and used solely for the storage of
chemical wastes;
·
Enclosed with at least 3 sides;
·
Impermeable floor and bund with capacity to
accommodate 110% of the volume of the largest container or 20% by volume of the
chemical waste stored in the area, whichever is greatest;
·
Adequate ventilation;
·
Sufficiently covered to prevent rainfall entering
(water collected within the bund must be tested and disposed of as chemical
waste, if necessary); and
·
Incompatible materials are adequately
separated.
(xviii)
All chemical waste, fuels
and oils shall be stored at the Site Office area, to minimise impacts to the
(xix) All maintenance activities which may generate chemical waste shall be undertaken in Site Office area, as far as possible.
(xx) The Contractor shall comply with WSD’s General Conditions for Working within Water Gathering Grounds;
(xxi)
Waste
oils, chemicals or solvents shall not be disposed of to drain.
(xxii)
Subject
to agreement with Water Service Department, adequate numbers of portable
toilets should be provided for on-site workers.
Portable toilets should be maintained in reasonable states, which will
not deter the workers from utilising them.
Night soil should be regularly collected by licensed collectors.
(xxiii)
General
refuse arising on-site should be stored in enclosed bins or compaction units
separately from C&D and chemical wastes.
General refuse shall be removed from Works Section 6 within the country
park on the daily basis. Sufficient dustbins shall be provided for storage of
waste as required under the Public Cleansing and Prevention of Nuisances
By-laws. In addition, general refuse
shall be cleared daily and shall be disposed of to the nearest licensed
landfill or refuse transfer station.
Burning of refuse on construction sites is prohibited.
(xxiv)
All
waste containers shall be in a secure area on hardstanding.
(xxv)
Aluminium
cans are usually collected and recovered from the waste stream by individual
collectors if they are segregated and easily accessible. Separately labelled bins for their deposition
should be provided as far as practicable.
(xxvi)
Office
wastes can be reduced by recycling of paper if such volume is sufficiently
large to warrant collection.
Participation in a local collection scheme by the Contractor should be
advocated. Waste separation facilities
for paper, aluminium cans, plastic bottles, etc should be provided on-site.
(xxvii)
Training
shall be provided to workers about the concepts of site cleanliness and
appropriate waste management procedure, including waste reduction, reuse and
recycling.
8.2.1.3 The following waste management measures should be implemented by the Contractor during the Operational Phase:
(i)
Non-inert
materials such as garbage and possibly vegetation will be disposed to WENT Landfill
via the Outlying Islands Transfer Facilities in Mui Wo;
(ii)
Inert
material, such as excess soil, sand and boulders, should be delivered from the
project site to the Tseung Kwan O Area 137 Fill Bank via the Public Fill
Reception Facility in Mui Wo or to WENT Landfill if the amount is negligible;
and
(iii)
No marine disposal of dredged/excavated
sediment would be involved in this project.
8.3 Waste Disposal Recommendations
8.3.1.1 The recommended disposal sites for the different types of waste are detailed in Table 8.1 below:
Table 8.1 Recommended Waste Disposal Sites
|
Type
of Waste |
Disposal
Site |
Quantity to be Disposed |
|
C&D materials |
TKO Area 137 Fill Bank via Public Fill
Reception Facility in Mui Wo |
Excavated soil: ~4,500 m3 Concrete debris and
aggregate: 300
m3 Excavated
rocks: ~2,300 m3 |
|
C&D waste (plastics, glass, wood, including
cleared vegetation etc.) |
WENT Landfill |
~100
tonnes |
|
Chemical waste (as defined under Schedule 1 of the
Waste Disposal (Chemical Waste) Regulation) |
Chemical Waste Treatment Centre in Tsing Yi or other
licensed facilities via licensed collectors |
< 3,000 L |
|
|
|
|
|
General refuse |
WENT Landfill via Outlying |
~16
tonnes |
Note: The small amount of ~15m3
of dewatered bentonite slurry would be disposed to a public filling area, and
liquid bentonite slurry, if mixed with inert fill material, would be disposed
to a public filling area.
8.4.1.1
EM&A is
recommended during the construction phase only and the effective management of
waste arisings during the construction phase will be monitored through the site
audit programme. Regular
audits and site inspections should be carried out by the Engineer, ET and
Contractor to ensure that the recommended good site practices and other
mitigation measures are implemented by the Contractor.
8.4.1.2
The audits should look at all aspects of on-site
waste management practices including the waste generation, storage, recycling,
transport and disposal. The aims of the
waste audit are:
·
to ensure the waste arising from the works are handled,
stored, collected, transferred and disposed of in an environmentally
acceptable manner;
·
verify
the implementation status and evaluate the effectiveness of the mitigation
measures; and
·
to
encourage the reuse and recycling of material.
8.4.1.3
Apart from
site inspections, documents including licenses, permits, disposal and recycling
records should be reviewed and audited for the compliance with the legislation
and contract requirements to ensure proper records are being maintained and
procedures undertaken in accordance with the Waste Management Plan
8.4.1.4
The
Contractor shall will required to pay attention to all relevant environmental legislation, standards and guidelines and carry out
appropriate waste management and obtain the relevant licence/permits for waste
disposal. The ET shall ensure that the
Contractor has obtained from the appropriate authorities the necessary waste
disposal permits or licences.
8.4.1.5
The
Contractor’s waste management practices should be audited with reference to the
checklist detailed in Table 8.2
below:
Table 8.2 Waste Management Checklist
|
Activities |
Timing |
Monitoring Frequency |
If non-compliance, Action Required |
|
All necessary waste disposal
permits or licences have been obtained |
Before the commencement of construction
works |
Once |
Apply for the necessary
permits/ licences prior to disposal of the waste. The ET shall ensure that corrective action
has been taken. |
|
Only licensed waste hauliers
are used for waste collection. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall instruct the Contractor to use a licensed waste haulier. The Contractor shall temporarily suspend
waste collection of that particular waste until a licensed waste haulier is
used. Corrective action shall be
undertaken within 48 hours. |
|
Records of quantities of wastes
generated, recycled and disposed are properly kept. For demolition material/waste, the number
of loads for each day shall be recorded (quantity of waste can then be
estimated based on average truck load.
Should landfill charging be implemented, the receipts of the charge
could be used for estimating the quantity). |
Throughout the works |
Weekly |
The Contractor shall estimate
the missing data based on previous records and the activities carried
out. The ET shall audit the results
and forward to the ER and IEC for approval. |
|
Wastes are removed from site
in a timely manner. General refuse is
collected on a daily basis. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall instruct the Contractor to remove waste accordingly. |
|
Waste storage areas are
properly cleaned and do not cause windblown litter and dust nuisance. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall instruct the Contractor to clean the storage area and/or cover the
waste. |
|
Different types of waste are
segregated in different containers or skip to enhance recycling of material
and proper disposal of waste. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall instruct the Contractor to provide separate skips/ containers. The Contractor shall ensure the workers
place the waste in the appropriate containers. |
|
Chemical wastes are stored,
handled and disposed of in accordance with the Code of Practice on the Packaging, Handling and Storage of Chemical
Wastes, published by the EPD. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall instruct the Contractor to rectify the problems immediately. Warning shall be given to the Contractor if
corrective actions are not taken within 24 hrs and the Waste Control Group of
the EPD shall be identified. |
|
Demolition material/waste in
dump trucks is properly covered before leaving the site. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall instruct the Contractor to comply.
The Contractor shall prevent trucks shall leaving the site until the
waste are properly covered. |
|
Wastes are disposal of at
licensed sites. |
Throughout the works |
Weekly |
The ET shall inform the ER
and IEC of the non-compliance. The ER
shall warn the Contractor and instruct the Contractor to ensure the wastes
are disposed of at the licensed sites.
Should it involve chemical waste, the Waste Control Group of EPD shall
be notified. |
Note: ET – Environmental Team, IEC– Independent Environmental
Checker, ER – Engineer’s Representative