6.1.1
This Chapter identifies
potential environmental impact resulting from the handling, collection and
disposal of the construction waste associated with the Project. It also
presents an assessment of the potential for the occurrence of land
contamination along the route of the Flyover.
6.1.2
The potential environmental
impacts concerning their handling, collection and disposal will be assessed in
accordance with the criteria and guidelines given in Annexes 7 and 15 of
EIAO-TM, while the potential environmental impacts of land contamination will
be assessed in accordance with the criteria and guidelines given in Sections
3.1 and 3.2 of Annex 19 of EIAO-TM.
6.1.3
Options for waste minimisation,
recycling, storage, collection, and disposal of waste arising from the Project
have been examined and procedures for minimising environmental impacts due to handling
and disposal of waste are recommended.
General
Waste Management
6.2.1
The following legislations are
related to the handling, treatment and disposal of waste in Hong Kong, and will
be considered in the assessment of potential impacts and waste management:
· Waste Disposal Ordinance (Cap
354);
· Land (Miscellaneous Provisions)
Ordinance (Cap 28); and
· Public Health and Municipal
Service Ordinance (Cap 132) – Public Cleansing and Prevention of Nuisances
By-laws.
6.2.2
The following subsidiary
regulations of the Waste Disposal Ordinance are also related:
· Waste Disposal (Chemical Waste)
(General) Regulation (Cap 354C); and
· Waste Disposal (Charges for
Disposal of Construction Waste) Regulation (Cap 354N).
Waste
Disposal Ordinance (Cap 354)
6.2.3
The Waste Disposal Ordinance
(WDO) prohibits any unauthorised disposal of wastes. Construction waste,
defined under Cap. 354N of the WDO means any substance, matter or thing that is
generated from construction works and abandoned, whether or not it has been
processed or stockpiled before being abandoned, but does not include any
sludge, screenings or matter removed in or generated from any desludging,
desilting or dredging works. Under WDO,
waste can be disposed of only at designated waste disposal facilities licensed
by the EPD.
6.2.4
Chemical wastes include
unwanted substances or chemicals causing pollution or impose a danger to health
or risk of pollution to the environment.
A person should not produce, or cause to be produced, any chemical
wastes unless he/she is registered with the EPD. Chemical wastes must be treated using on-site
plant as licensed by the EPD or with engaging a licensed collector to transport
the wastes to a licensed facility. For each consignment of wastes, the waste
producer, collector and disposer must sign all relevant parts of a computerised
trip ticket so as to trace wastes from production to disposal.
6.2.5
This regulation also prescribes
the storage facilities to be provided on-site including the labelling and
warning signs. To minimise the risks of
pollution and danger to human health and life, waste producers are required to
prepare and make available written emergency procedures for any spillage, leakage
or accidents arising from storage of chemical wastes. The waste producers must also provide
employees with training for such procedures.
Waste Disposal (Charges for
Disposal of Construction Waste) Regulation (Cap 354N)
6.2.6
Under the WDO and the Charging
Regulation, wastes can only be disposed of at designated waste disposal
facilities licensed by EPD. Schedule 5
of Regulation defines that inert construction waste includes rock, rubble,
boulder, earth, soil, sand, concrete, brick, tile, masonry or used bentonite. According to Schedule 6 of the Regulation,
construction waste delivered to a landfill for disposal must not contain more
than 50% by weight of inert material while those to a sorting facility for
disposal must contain more than 50% by weight of inert material. Whereas
construction waste delivered to a public fill reception facility for disposal
must consist entirely of inert material.
6.2.7
For construction work with a
value of more than HK$1 million, the main contractor is required to establish a
billing account at the EPD before transporting the construction waste to the
designated waste disposal facilities (for example, landfill and public fill).
The vessels for delivering construction waste to the public fill reception
facilities require prior approval from the Public Fill Committee (PFC). Any breach of these regulations may lead to a
fine and/or imprisonment.
Land (Miscellaneous
Provisions) Ordinance (Cap 28)
6.2.8
The inert portion of
Construction and Demolition (C&D) materials (including rocks, soil, broken
concrete, building debris, etc.) may be taken to public fill reception
facilities (PFRFs). PFRFs usually form
part of land reclamation schemes and are operated by the Civil Engineering and
Development Department (CEDD) and others.
The Land (Miscellaneous Provisions) Ordinance requires individuals or
companies who deliver public fill to PFRFs to obtain Dumping Licences. The licences are issued by CEDD under
delegated authority from the Director of Lands.
6.2.9
Individual licences and
windscreen stickers are issued for each vehicle involved. Under the licence conditions, PFRFs will only
accept inert construction waste. In addition, in accordance with paragraph 12
of the Development Bureau (DevB) Technical Circular (Works) TC(W) No.6/2010,
PFC will advise on the acceptance criteria.
The material will, however, be free from marine mud, household refuse,
plastic, metal, industrial and chemical wastes, animal and vegetable matter and
any other materials considered unsuitable by the PFRF supervisor.
Public
Cleansing and Prevention of Nuisances Regulation (Cap 132)
6.2.10
This regulation provides
further control on the illegal dumping of litter or waste in streets and public
places (including water courses, streams, channels etc). Offence to this regulation would result in a
fine and/or to imprisonment.
Other
Relevant Guidelines
6.2.11
The
following guidelines are also relevant to waste management in Hong
Kong:
· Code of Practice on the Packaging,
Labelling and Storage of Chemical Wastes (1992), EPD ;
· Works Branch Technical Circular
(WBTC) No. 32/92, The Use of Tropical Hard Wood on Construction Site;
· WBTC No. 2/93, Public Dumps;
· WBTC No. 2/93B, Public Filling
Facilities;
· WBTC Nos. 25/99, 25/99A and
25/99C, Incorporation of Information on Construction and Demolition Material
Management in Public Works Subcommittee Papers;
· WBTC No. 12/2000, Fill Management;
· WBTC Nos. 6/2002 and 6/2002A,
Enhanced Specification for Site Cleanliness and Tidiness;
· WBTC No. 11/2002, Control of Site
Crusher;
· WBTC No. 12/2002, Specification
Facilitating the Use of Recycled Aggregates;
· Environment Transport and Works
Bureau Technical Circular (Works) (ETWB TC(W)) No. 33/2002 Management of
Construction and Demolition Material
Including Rock;
· ETWB TC(W) No. 19/2005
Environmental Management on Construction Sites; and
· DevB TC(W) No. 6/2010, Trip Ticket
System for Disposal of Construction & Demolition Materials, Development
Bureau.
6.2.12
The
ETWB TC(W) No. 19/2005 sets out the policy and procedures requiring contractors
to prepare and implement an Environmental Management Plan (EMP) to abate
environmental nuisances on construction site and reduce C&D material to be
disposed of during construction.
Contaminated
Land
6.2.13
The
following legislations are related to the land contamination issues concerning
handling, treatment and disposal of contaminated materials:
· Waste Disposal Ordinance (Cap
354);
· Waste Disposal (Chemical Waste)
(General) Regulation (Cap 354C); and
· Dangerous Goods Ordinance (Cap
295).
6.2.14
The
following EPD publications provide guidance on the land contamination
assessment in this Assignment:
· Practice Guide for Investigation
and Remediation of Contaminated Land (August 2011);
· Guidance Note for Contaminated
Land Assessment and Remediation (December 2007); and
· Guidance Manual for Use of Risk-Based
Remediation Goals (RBRGs) for Contaminated Land Management (August 2007).
6.3.1
The assessment of waste
management implications has been conducted in accordance with Annexes 7 and 15
of the EIAO-TM. This includes:
· Estimation of types and quantities
of wastes generated;
· Assessment of potential impact
caused by handling (including labelling, packaging and storage), collection,
and disposal of wastes with respect to potential hazard, air and odour emission,
noise, wastewater discharge and public transport; and
· Determination of practical
mitigation measures for the environmental impacts.
6.4.1
Construction activities will
result in the generation of a variety of wastes which can be divided into
distinct categories based on their constituents, as follows:
· Inert C&D material (inert
portion of C&D material);
· C&D Waste (non-inert portion
of C&D material);
· Marine Sediment;
· Chemical waste; and
· General refuse.
6.4.2
The operational phase of the
proposed project is not expected to generate any waste.
Construction
Phase
6.5.1
The nature and preliminary
quantities of each of these waste types arising from the construction phase of
the proposed works are identified below. The detailed calculations of materials
and waste arising are required to be submitted to Government under the
requirements of WBTC 25/99 during the detailed design. Table 6-1 summarises the estimated quantities of different types of
waste arising from the Project.
Table 6-1 Summary of Estimated Quantities of Waste
Arising from Construction Phase
|
Waste Type
|
Source
|
Total
Quantity
|
Handling
|
Quantity
to be Reused On-site
|
Quantity to
be Disposed of Off-site
|
|
Inert C&D material
|
Excavation for foundation
|
4,730 m3
|
Reuse on-site or disposed off-site to public
fill reception facilities in Tuen Mun Area 38 Fill Bank
|
4,810 m3 of inert C&D
material as fill material
|
1,140 m3 inert C&D material [1]
|
|
Excavation for at grade road construction
|
100m3
|
|
Excavation for other works (e.g. demolition
works, utility diversion)
|
930 m3
|
|
C&D Waste
|
Cleared vegetation; wood from formwork; unusable
cement mixes; and damaged or contaminated construction materials
|
655 m3
|
Sent to WENT landfill
|
--
|
790 m3
|
|
Marine Sediment
|
Excavation for piling and foundation works
|
400m3
|
Treatment for decontamination, if necessary followed
by cement stabilisation for treated and uncontaminated marine sediment
|
480m3 [2] as fill
material for abutment after treatment
|
--
|
|
Chemical Waste
|
Scrap batteries, spent acid/alkali, spent
mineral oil/ cleaning fluid, spent solvent, engine oil and fuel from
construction plants or equipment
|
Few hundred litres per month
|
Stored on-site within suitably designed
containers and collected by licensed company
|
--
|
Few hundred litres per month
|
|
General Refuse
|
Food waste, waste paper, aluminium cans etc
generated from workforce
|
Few hundred kilogrammes per day in the peak period
|
Sorted recyclables sent to recycling
company, other non-recyclable refuse collected by on-site refuse collection
point and transferred to landfill
|
--
|
Few hundred kilogrammes per day in the peak period
|
Note:
[1] A
factor of 1.2 is applied in the estimate of inert C&D material and C&D
waste quantity to be disposed of off-site.
[2]
The volume of the marine sediment after cement stabilisation
will be increased by around 20%.
Inert Construction
and Demolition (C&D) Material
6.5.2
Inert C&D material would be
generated during the construction of proposed bridges including the foundation,
substructure and superstructure works, and the reprovisioning work of the
footbridge. Types of inert C&D material include soil, rock, concrete,
bituminous material etc. The total quantity of the inert C&D material
generated in the Project is estimated to be approximately 5,760 m3.
Among this, about 4,810 m3 of inert C&D material would be reused
on-site as fill material. Approximately 1,140 m3 of inert C&D
material would be disposed to public fill reception facilities in Tuen Mun Area
38 Fill Bank for other beneficial uses with accounting a factor of 1.2 in the
estimate of inert C&D material quantity to be disposed of off-site.
6.5.3
The site for the Public Works
Regional Laboratory of Tsuen Wan (Laboratory Site), which is currently
allocated to CGE/Standards & Testing of CEDD, is proposed to be the site
office and stockpiling area for those inert C&D material not immediately
disposed during construction phase.
C&D Waste
6.5.4
In addition to the inert
C&D material that would be generated, as noted above, which are suitable
for reuse on site or as public fill, some C&D waste would, also, be
generated during the construction phase. These materials include:
· Any cleared vegetation;
· Wood from formwork;
· Unusable cement mixes; and
· Damaged or contaminated
construction materials.
6.5.5
About 655 m3 of
C&D waste would be generated during construction phase. They will be
disposed to WENT Landfill. A factor of 1.2 is applied in the estimate of
C&D waste quantity to be disposed of off-site and therefore the quantity of
C&D waste to be disposed off-site is 790 m3.
Marine Sediment
6.5.6
According to the existing
information from Geotechnical Investigation (GI) records, marine sediment has
been identified in the reclamation area within the Project Site. It is
estimated that approximately 400m3 of marine sediment will be
excavated from the reclaimed land due to the piling works for the proposed
bridges in the Project. The assessed volume will be verified during detailed
design stage of the Project in future.
6.5.7
A common way of handling marine
sediment in local construction industry is disposing of it to marine dumping
sites in accordance with ETWB TC No 34/2002 and Dumping at Sea Ordinance, Cap.
466 (DASO). However, recent public concerns are growing on the high levels of
heavy metal contents found in some common seafood species due to serious sea
water pollution.
6.5.8
One method to address this
environmental issue is by treatment and reuse of the dredged marine sediment
rather than disposing it to the sea.
6.5.9
With reference from overseas’ and
Hong Kong’s cases, reuse of the dredged sediment on-site with treatment, if
necessary, is proposed to this Project, a preliminary contamination assessment
for the site of marine sediment was conducted in accordance with the following
Technical Memorandum and Guidance Notes published by the EPD:
· Practice Guide for Investigation
and Remediation of Contaminated Land, August 2011 (Practice Guide);
· Guidance Note for Contamination
Land Assessment and Remediation, August 2007 (Guidance Note); and
· Guidance Manual for Use of
Risk-Based Remediation Goals (RBRGs) for Contaminated Land Management, December
2007 (Guidance Manual).
6.5.10
Possible ex-situ treatment and
beneficial reuse options are identified to demonstrate that no environmentally
unacceptable impact would be resulted from the excavation, treatment and reuse
of marine sediment.
6.5.11
The preliminary contamination
assessment and possible ex-situ treatment and beneficial reuse options for the
marine sediment to be excavated in this Project is presented as follows:
Initial Contamination Evaluation of the Site for Marine Sediment
6.5.12
The history information of the
site with possible excavation of marine sediment (Site with Marine Sediment)
was obtained by reviewing the relevant aerial photographs. The aerial
photographs are shown in Appendix 6-2.
Table 6-2 summarises the findings of
the aerial photographs reviewed.
Table 6-2 Findings of Aerial Photographs Reviewed for
the Site with Possible Excavation of Marine Sediment
|
Year
|
Notes
|
|
1963
|
The Site
with Marine Sediment
comprises natural hillside and sea where there were a lot of fishing boats
around the site.
|
|
1973
|
Extensive reclamation has taken
place at the Site with Marine Sediment.
|
6.5.13
As observed from the aerial photograph
of 1963 in Appendix 6-2 the Site
with Marine Sediment, is located on the sea in 1963. From the aerial photograph
of 1973, the site was reclaimed.
6.5.14
As the Site with Marine
Sediment is located in the urban area where there was industrial development
nearby from 1950s, local discharge of polluted effluent from industrial uses
might impose a potential cause to contaminate the marine sediment in the sea
before reclamation of the site.
6.5.15
From a conservative point of view,
it is proposed to conduct a site investigation with environmental sampling and
analysis during detailed design stage of this Project on the Site with Marine
Sediment to identify the contamination extent of the marine sediment.
6.5.16
As the marine sediment was
potentially contaminated by local discharge of polluted effluent from many
unknown uses, the potential contaminants may include semi-volatile organic
compounds (SVOCs), metals, polychlorinated biphenyl, petroleum carbon ranges
(PCRs) and organometallics.
6.5.17
It is proposed that the samples
could be collected at where the excavation of marine sediment to be conducted
which are the locations for piles. Exact sampling locations and numbers shall
be identified with the updated information during detailed design stage. The
proposed locations of works with possible marine sediment excavation with the
past geotechnical investigation records showing the locations of samples for
marine sediment are shown in Figure 6-1
6.5.18
Among the four different
post-restoration land use categories, namely “Urban Residential”, “Rural
Residential”, “Industrial” and “Public Parks”, “Public Park” is the most
relevant use to the proposed development as flyover from Kwai Tsing Interchange
Upramp to Kwai Chung Road as they are both open space of good ventilation and
with transient receivers. Therefore, it is suggested that the contamination
extent of the marine sediment excavated should be checked against the RBRGs for
soil for “Public Park” as the marine sediment is proposed to be re-used
on-site.
6.5.19
Samples of marine sediment
should be collected and analysed against the RBRGs for soil for Public Park.
The RBRGs for soil is presented in Appendix
6-1.
6.5.20
A more detailed assessment and
environmental investigation for marine sampling and analysis shall be carried
out during the detailed design stage of this Project.
6.5.21
A Sediment Assessment Plan
shall be submitted with the updated information during the detailed design
stage and obtain EPD’s approval before the environmental investigation. A
Sediment Assessment Report / Sediment Remediation Plan should be prepared
pending the result of environmental investigation for EPD’s approval before
treatment and reuse of marine sediment.
Possible Remediation Options
6.5.22
With reference from the
consultancy study – FM01/2007 by CEDD on various management options for marine
sediment in Hong Kong [1], the following presents possible remediation options for treatment
of marine sediment exceeding the proposed RBRGs for this Project.
(a)
Mechanical Dewatering
This
technique separates water from the sediments by mechanical means such as belt
filter presses and centrifuge. The advantages are high capacity, and it can be easily
increased by using additional presses. Also, it requires small area for
installation. Moreover, dewatering is effective and efficient. However, it
requires relatively high investment and operation costs. Besides, treated
sediments after dewatering may be still considered contaminated which requires
further treatment.
This
is applied in St. Lawrence River in Canada (EC. 1995). Shallow areas that posed a navigational hazard in the St.
Lawrence River at the Port of Sorel were dredged and found to contain elevated
levels of metals (EC, 1995). The project utilised a rotatory press and
additives to remove water and decontaminate approximately 5,000m3 of
sediment along the river. The rotary
press reduced the volume of sediments 5 to 10 times and the dryness level went
from 15% to 72% of total particulate matter during dewatering.[2]
(b)
Biological Remediation
This
option makes use of bio-oxidation of organic matter by micro-organisms to break
down Polychlorinated Biphenyls (PCBs), pesticides, and other organic
constituents into less toxic compounds. It has high removal efficiency for PCRs
and polycyclic aromatic hydrocarbon (PAHs) but the treatment time is relatively
long. The presence of heavy metals can inhibit microbial metabolism and thus
affects the removal efficiency.
The
Stauffer Management Company Superfund Site is an inactive pesticide
manufacturing/distribution facility in Tampa, Florida. From 1951 to 1986, the
site was used to formulate organochlorine and organophosphate pesticides. From
1953 to 1973, waste materials from the facility were disposed on site, leading
to pesticide contamination in soil, surface water, sediment, and groundwater.
Bioremediation was adopted from 1997 to 1998 for treatment of
pesticide-contaminated surface soils and sediments at the site.
Concentrations of toxaphene were reduced by
more than 90% and chlordane by nearly 90%. [3]
(c)
Chemical Treatment
Oxidation, reduction, hydrolysis or
neutralisation are the available technologies for chemical treatment. The
benefits are low energy consumption and relatively rapid process. However, as
treatment methods are specific to particular contaminants or classes of
compounds, selection of method and reagent is important to the success of the
process.
A research on separating the Tributyltin
(TBT) contaminated seawater from the dredged marine sediment was undertaken by
the Kyushu University in Japan. It is reported that TBT was successfully separated
from the contaminated seawater by applying coagulant called PSl-100 as well as
filtering the water through fibre sheet, sand and activated carbon. Following
the treatment, the concentration of TBT was reduced from 1,200-1,450ng/L to
3ng/L.
(d)
Thermal Destruction /
Incineration
It is the most widely operation used for
destroying organic contaminants in which the organic contaminants are
volatilised at temperatures greater than 1000°F in the presence of oxygen
resulting in combustion and destruction of the contaminants. It is effective
that incineration typically achieve greater than 99% destruction for organics.
However this option is relatively expensive and not effective on heavy metals.
Additional handling / treatment of by-products such as residue contaminants in
ash, gaseous emissions and wastewater is required.
The Drake Chemical Superfund (DCS) Site
included a chemical manufacturing facility that operated from 1951 to 1982,
producing chemical intermediates used in dye, cosmetic, textile, pharmaceutical,
pesticide and herbicide manufacturing. Drums of chemical waste, chemical
sludge, and demolition debris were disposed on the ground surface and in the
shallow subsurface at the site. Site soil and chemical sludge were contaminated
with volatile organic compounds (VOCs), SVOCs and metals.
The incinerator was in full-scale
operation from 1998 to 1999 as the remedial technology for addressing soil
contamination at the site. All site soil was excavated down to the water table and
treated. Treated soil and fly ash that met treatment standards were used as
fill material at the site. [3]
(e)
Sediment Washing
Sediment washing is a water-based process
for mechanically scrubbing excavated sediment to remove contaminant and
contaminants from sediment either by dissolving or suspending them in a wash
solution. A wide variety of sediment contaminated with soluble metals,
halogenated solvents, aromatics, gasoline, fuel oils, PCBs, chlorinated phenols
and pesticides can be treated with this method with high removal efficiency.
The treatment cost is relatively high and this process cannot efficiently treat
fine particles, low-permeability packed materials, or sediment with high humic
content.
Advanced Sediment Washing Technology is
marketed jointly by WESTON and BioGenesis, West Chester, PA. This technology is
a multistaged sediment washing and organic oxidation process for
decontaminating dredged sediments and producing a marketable fine-grained
soil-like product for reuse after the addition of bulking materials. During the
process, organic material is stripped from the solid particles and chemically
oxidised. [4]
(f)
Immobilisation / Solidification / Stabilisation
Reactive materials are mixed with the
marine sediment to immobilise contaminants. Available technology in market
includes microencapsulation, cement-based solidification and silicate-based
solidification. It operates most
successfully in wastes with inorganics and metals and is a relatively less
expensive technique. The treated sediment can be reused as fill material for
construction works. Nevertheless, it is not effective on volatile organics and
the effectiveness on organics or other leachables is inconclusive.
Sediments at the New York/New Jersey
Harbour were contaminated with organochlorine pesticide, PAHs, PCBs, dioxins
and furans and metals. Immobilisation was adopted in the treatment of the
contaminated sediment. The treatment of the material was done in a barge.
Stabilised materials have been used as structure fill at a parking lot and
capping brownfield site in New Jersey.[5]
Sediments excavated for South Island Line
(East) were sampled and tested in accordance with ETWB TC(W) No. 34/2002 and
were found contaminated with copper and zinc. Cement stabilisation was adopted
to treat the metal contaminated sediment. The cement stabilised materials were
used as fill on-site in 2014.[6]
Treatment and Outlet of Decontaminated or Uncontaminated Marine Sediment
6.5.23
The applicant shall propose in
the Sediment Assessment Report / Sediment Remediation Plan the remedial
measures for decontaminating marine sediment based on the results from
environmental investigation and the clean-up criteria for the contaminated
marine sediment for agreement with EPD.
6.5.24
It is proposed to locate the
treatment facilities at the Laboratory Site or the area just near to the piling
works where marine sediment is excavated, depending on where it is excavated
and the area required for the treatment.
6.5.25
It is proposed to reuse the
marine sediment as fill material for abutment of the proposed Bridge H. Unless
solidification or stabilisation process is chosen as the remediation option for
the contaminated marine sediment, to reuse the marine sediment as fill
material, the decontaminated or uncontaminated marine sediment should undergo
cement stabilisation process for improvement of the structural stability. After
cement stabilisation process, it is expected the volume of the treated marine
sediment will expand by 10-20%.
6.5.26
The cement stabilised marine
sediment shall comply the criteria agreed upon with EPD, for example Universal
Treatment Standards (UTS) and Unconfined Compressive Strength (UCS) standard,
in accordance with the Practice Guide.
6.5.27
With identification of proper
treatment methods for the excavated marine sediment pending the results of site
investigation, no environmental impact is anticipated from the excavation,
treatment and reuse of the marine sediment.
Chemical Waste
6.5.28
Chemical Waste, as defined
under the Waste Disposal (Chemical Waste) (General) Regulation, includes any
substance being scrap material, or unwanted substances specified under Schedule
1 of the Regulation. A complete list of such substances is provided under the
Regulation, however, substances likely to be generated by construction
activities will, for the most part, arise from the maintenance of equipment.
These may include, but not limited to, the followings:
· Scrap batteries or spent
acid/alkali from their maintenance;
· Used engine oils, hydraulic fluids
and waste fuel;
· Spent mineral oils/cleaning fluids
from mechanical machinery; and
· Spent solvents/solutions, some of
which may be halogenated, from equipment cleaning activities.
6.5.29
It is difficult to quantify the
amount of chemical waste which will arise from the construction activities as
it will be highly dependent on the Contractor's on-site maintenance intention
and the number of plants and vehicles utilised. However, it is anticipated that
the quantity of chemical waste, such as lubricating oil and solvent produced
from plant maintenance will be small, (in the order of a couple of hundred
litres per month) and will be readily accepted at the Chemical Waste Treatment
Centre (CWTC) or other licensed waste oil recycling facilities. The actual
amount of chemical wastes generated should be quantified and recorded in the
Site Waste Management Plan to be prepared by the Contractor.
General Refuse
6.5.30
Construction site workers, site
offices and canteens will result in the generation of a variety of general
refuse requiring disposal. General refuse generated on site will mainly consist
of food wastes, aluminium cans and waste paper.
6.5.31
The maximum number of workers
and peak activities on-site are expected around the mid of Year 2019 to mid of
Year 2020, hence the site will produce the highest volume of general refuse.
Operation
Phase
6.5.32
The operational phase of the
proposed Project is not expected to generate any waste and thus no significant
waste implications during the operational phase are predicted.
Timing
of Waste Generation
6.5.33
Based on the preliminary
construction programme, the construction will be carried out from 2018 to
2021. A tentative estimated timing of
waste arising is shown in Table 6-3.
Table 6-3 Tentative Estimated Timing of Waste
Arising
|
Type
of Waste
|
Months
|
|
Construction Phase
|
|
Inert C&D Material
|
M1 to M37
|
|
C&D Waste
|
M1 to M37
|
|
Marine Sediment
|
M3 to M7 and M20 to M23
|
|
Chemical Waste
|
Entire construction phase
|
|
General Refuse
|
Transportation
Frequency and Route
6.5.34
The peak generation of the
inert C&D material and C&D waste is expected during the foundation
works of Bridge H including excavated soil and construction debris such as the used
formworks at the months M22-M23 of the tentative
construction programme. Among this period, all the inert C&D material and
C&D waste will be transported to the stockpiling area at the Laboratory
Site via Kwai Chung Road and Tsuen Wan Road, pending for sorting and
backfilling or disposal. Assuming 24 working days monthly, the daily generation rate of the inert C&D material and C&D waste estimated from the tentative construction
programme is 33.5m3. Assuming a density of 2 tonnes/m3, approximately 7
trucks (10 tonnes loading capacity per truck) per day will be used to transport
this amount of the inert C&D material and C&D
waste to the stockpiling area.
6.5.35
Backfilling of the inert
C&D material will be carried out from M24 to M27, after which the remaining
inert C&D material and the C&D waste stockpiled before this period will
be disposed off site within M28 which is considered as the peak period for
disposal. Based on the tentative construction programme, the estimated quantity
of inert C&D material and the C&D waste for disposal within M28 is expected to be 1116m3 and 216m3
after applying a factor of 1.2. The inert C&D material and C&D waste
for disposal would be delivered to the public fill reception facilities and the landfill respectively. Assuming 24 working days monthly, the daily disposal rate of the inert C&D material and C&D waste is 46.5m3 and 9m3 respectively. Assuming a density of 2 tonnes/m3,
approximately 10 trucks (10 tonnes loading capacity per truck) per day would deliver the inert C&D material to Tuen Mun Area 38 Fill Bank
and approximately 2 trucks (10 tonnes loading capacity per truck) per day would deliver
the C&D waste to WENT Landfill for disposal in a month. No
barging point and conveyor will be used.
Other inert C&D material and C&D waste will be generated and
disposed at later time during off-peak period.
6.5.36
The inert C&D material for
disposal will be transported to Tuen Mun Area 38 Fill Bank via Tsuen Wan Road,
Tuen Mun Road, Lung Mun Road while the C&D waste will be further
transported to WENT
Landfill via Lung Kwa Tan Road and Nim Wan Road.
6.5.37
The marine sediment excavated
will be transported to the treatment facilities at the Laboratory Site or the
area just near to the piling works where marine sediment is excavated during
the period for excavation from M3 to M7 and M20 to 23. As the choice of
location depends on where the marine sediment is excavated and the area
required for the treatment, the transportation frequency and route cannot be
provided at this stage.
6.5.38
As the quantity of chemical
waste and general refuse is small, the chemical waste will be collected by licensed company in a truck
monthly while general refuse will be collected by licensed collector and sent
to WENT Landfill daily via the same route as C&D waste.
6.6
Mitigation of Adverse
Environmental Impacts
6.6.1
The Contractor is responsible
for the management of materials and wastes during construction. This includes
control of wastes on site, removal of the waste materials from the site and the
implementation of any mitigation measures to minimise waste or redress any
problems that arise from waste associated with the works.
6.6.2
This section sets out the
measures to be adopted to avoid or minimise potential adverse impacts
associated with waste arising from the works under the headings of each waste
type. The Contractor should incorporate these recommendations into a
comprehensive on-site Waste Management Plan, (WMP). If, for any reason, the
recommendations cannot be implemented, full justification should be given in
the WMP.
6.6.3
In accordance with ETWB TC(W)
No. 19/2005 – Environmental Management
on Construction Sites, the WMP should be prepared and submitted for approval by
the Architect/ Engineer/ Supervising Officer prior to any construction
activities. During the construction period the WMP should be used as a working
document to detail the on-going management procedures and to record waste
arising from construction works and import of fill throughout the Contract. The
WMP shall be subject to audit under the requirements of the Environmental
Monitoring and Audit (EM&A) Procedures set out in the EM&A Manual
accompanying this EIA Report.
Waste
Management Hierarchy
6.6.4
The WMP shall be developed and
implemented according to a best-practice philosophy of waste management. There
are various waste management options, which can be categorised in terms of
preference from an environmental viewpoint. The options considered to be more
preferable have the least impacts and are more sustainable in a long-term
context. The hierarchy shall be as follows:
· Avoidance and minimisation, i.e.
avoiding or not generating waste through changing or improving practices and
design;
· Reuse of materials, thus avoiding
disposal (generally with only limited reprocessing);
· Recovery and recycling, thus
avoiding disposal (although reprocessing may be required); and
· Treatment and disposal, according
to relevant laws, guidelines and good practice.
6.6.5
The suitability (or otherwise)
of material for reuse on site shall be detailed in the WMP. If, for any reason,
the recommendations cannot be implemented, full justification should be given
in the WMP for approval by Architect/Engineer/Supervising Officer according to ETWB TC(W) No. 19/2005.
Training
6.6.6
To facilitate adoption of the
best-practice philosophy, training shall be provided to all personnel working
on site. The training shall promote the concept of general site cleanliness and
clearly explain the appropriate waste management procedures defined in the WMP.
Overall, the training should encourage all workers to reduce, reuse and recycle
wastes.
Records
of Waste and Management
6.6.7
During construction, the WMP
should be kept up-to-date on a monthly basis with records of the actual
quantities of wastes generated, recycled and disposed of off-site. Quantities
shall be determined by weighing each load or other methods agreed to by the
Engineer’s Representative. Waste shall only be disposed of at licensed sites
and the WMP should include procedures to ensure that illegal disposal of wastes
does not occur. Only waste haulers authorised to collect the specific category
of waste concerned should be employed and a trip ticket system shall be
implemented for offsite disposal of inert C&D material and C&D waste at
public fill reception facilities and landfills. Appropriate measures should be
employed to minimise windblown litter and dust during transportation by either
covering trucks or transporting wastes in enclosed containers.
Site
Planning
6.6.8
Work site(s) shall be arranged
and managed to facilitate the proper management of wastes and materials. The
WMP shall include plans indicating specific areas designated for the storage of
particular types of waste, reusable and recyclable materials as well as areas
and management proposals for any stockpiling areas. Waste storage areas should
be well maintained and cleaned regularly. Specific provisions for different
types of material are outlined below. In general, these areas should be
designed to avoid cross contamination of materials as well as pollution of the
surrounding environment.
Inert
Construction and Demolition (C&D) Material / C&D Waste
6.6.9
In order to minimise the impact
resulting from collection and transportation of inert C&D material for
off-site disposal, it is recommended that the excavated fill material should be
reused on site as backfill material as far as possible. Also, careful design,
planning and good site management should be maintained in order to minimise over
ordering and generation of surplus materials such as concrete, mortars and
cement grouts. The design of formwork should maximise the use of standard
wooden panels so that high reuse levels can be achieved. Alternatives such as
steel formwork or plastic facing should be considered to increase the potential
for reuse.
6.6.10
Inert C&D material should
be segregated on site into different waste and material types. This will
increase the feasibility of certain components of the waste stream being
recycled by specialised contractors. The Contractor should clearly demonstrate
in the WMP how he intends to maximise the reuse of inert C&D material
on-site. Where reuse of materials on site is not feasible, the Contractor
should explore opportunities for recycling materials off-site. Inert C&D
material shall be reused on site as much as possible or recycled.
6.6.11
Potential opportunities for
recycling and reuse of inert C&D material from the Project include:
· Milling wastes arising from
regrading of the existing pavement could be recycled on site and reused as
either road-base in the new carriageways or fill for new embankments;
· Existing marginal roadside
barriers comprise pre-cast units, which may be possible to be reused in the
following widening works; and
· Existing bridge parapets comprise
aluminium post and railings, which have a recyclable value and could be sold
for reconditioning or reused for scrap metal.
6.6.12
Any stockpile should be sited
away from existing watercourses and suitably covered to prevent wind erosion
and impacts on air and water quality. Measures for impacts on air and water
quality are described in Sections 3
and 5 in this report, respectively.
6.6.13
C&D waste which cannot be
reused or recycled should be segregated and stored in different containers or
skips from the inert C&D material and should be disposed of to landfill.
Marine
Sediment
6.6.14
In order to minimise the
exposure to contaminated materials, workers should, when necessary, wear
appropriate personal protective equipment (PPE) when handling contaminated
sediments. Adequate washing and cleaning facilities should also be provided on
site.
6.6.15
In order to minimise any
potential adverse impacts arising from the handling, treatment and reuse of the
marine sediment, it should be excavated, transported and processed properly. Stockpiling
of contaminated sediments should be avoided as far as possible. If temporary
stockpiling of contaminated sediments is necessary, the excavated sediment
should be covered by tarpaulin and the area should be placed within earth bunds
or sand bags to prevent leachate from entering the ground, nearby drains and
surrounding water bodies. The stockpiling areas should be completely paved or
covered by linings in order to avoid contamination to underlying soil or
groundwater. Separate and clearly defined areas should be provided for
stockpiling of contaminated and uncontaminated materials. Leachate, if any,
should be collected and discharged according to the WPCO.
6.6.16
The approved Sediment
Assessment Plan and Sediment Assessment Report with Remediation Plan shall be
incorporated to the WMP.
Chemical
Waste
6.6.17
Chemical waste should be
handled in accordance with the Code of
Practice on the Packaging, Labelling and Storage of Chemical Wastes as
follows. Containers used for the storage of chemical wastes should:
· Be suitable for the substance they
are holding, resistant to corrosion, maintained in a good condition, and
securely closed;
· Have a capacity of less than 450L
unless the specifications have been approved by the EPD; and
· Display a label in English and
Chinese in accordance with instructions prescribed in Schedule 2 of the Waste
Disposal (Chemical Waste) (General) Regulation (Cap. 354C).
6.6.18
The storage area for chemical
wastes should:
· Be clearly labelled and used
solely for the storage of chemical waste;
· Be enclosed on at least 3 sides;
· Have an impermeable floor and
bunding, of capacity to accommodate 110% of the volume of the largest container
or 20% by volume of the chemical waste stored in that area, whichever is the
greatest;
· Have adequate ventilation;
· Be covered to prevent rainfall
entering (water collected within the bund must be tested and disposed as
chemical waste if necessary); and
· Be arranged so that incompatible
materials are adequately separated.
6.6.19
The Contractor shall register
with EPD as a Chemical Waste Producer. Waste oils and other chemical wastes as
defined in the CAP 354C will require disposal by appropriate means and
could require pre-notification to EPD prior to disposal. Appropriate means
include disposal:
· Via a licensed waste collector;
and
· To a facility licensed to receive
chemical waste, such as the CWTC which also offers a chemical waste collection
service and can supply the necessary storage containers; or
General
Refuse
6.6.20
General refuse generated
on-site should be stored in enclosed bins or compaction units separate from
construction and chemical wastes. A reputable waste collector should be
employed by the Contractor to remove general refuse from the site, separately
from construction and chemical wastes, on a daily or every second day basis to
minimise odour, pest and litter impacts. The burning of refuse on construction
sites is prohibited by law.
6.6.21
General refuse is generated
largely by food service activities on site, so reusable rather than disposable
dishware should be used if feasible. Aluminium cans are often recovered from
the waste stream by individual collectors if they are segregated or easily
accessible. Therefore separate, labelled bins for their deposit should be
provided if feasible.
6.6.22
Office waste can be reduced
through recycling of paper if volume is large enough to warrant collection.
Participation in a local collection scheme should be considered if one is
available.
6.7.1
The Project is likely to result
in the generation of a variety of wastes and require management and disposal of
inert C&D material and C&D waste, marine sediment, chemical waste and
general refuse. Provided that the wastes are managed by implementing all the
recommended measures, no unacceptable adverse environmental impacts arising from
the handling, storage, transportation or disposal of the wastes generated by
the Project would be envisaged.
6.8.1
It is the Contractor’s
responsibility to ensure that all wastes produced during the construction of
the Project are handled, stored, and disposed of in accordance with good waste
management practices and relevant regulations and requirements. The mitigation
measures recommended in Section 6.6
should form a basis of the WMP to be developed by the Contractor in the
construction phase of the Project.
Methodology
6.9.1
The objective of this
assessment is to identify and evaluate the potential soil contamination along
the Project Site and if required, develop an assessment plan to determine the
extent of any contamination present. In order to achieve this, the following
has been undertaken:
· Review of the current and
historical land use of the site to evaluate whether there is the potential for any
soil or groundwater contamination to have occurred;
· Assess any potential environmental
impacts arising as a result of land contamination or during future use of the
land; and
· Site visits to confirm land uses
and likely impacts of any land contamination identified.
6.9.2
Site visits were undertaken on
the 7 and 28 November 2013 along the road alignment to confirm land uses and
identify potential land contamination sources.
Review
of Aerial Photographs and Historic Land Uses
6.9.3
The site history information of
the Study Area was obtained by reviewing the relevant aerial photographs. The
aerial photographs are shown in Appendix
6-2. Table 6-4 summarises the
findings of the aerial photographs reviewed.
Table 6-4 Findings of Aerial Photographs Reviewed
for Project Site
|
Year
|
Notes
|
|
1963
|
The study area comprises natural
hillside, anthropogenic terrace and sea.
|
|
1973
|
Extensive reclamation has taken
place at the study area. Kwai Chung Road has been constructed
|
|
1982
|
Tsuen Wan Road and flyovers were
constructed. The Tsuen Wan Line was constructed. The land between the
elevated section of Tsuen Wan Road and the Tsuen Wan Line has been cleared.
|
|
1993
|
Container Port Road South was
constructed. Temporary buildings were constructed in 1983 and removed in 1989
at the area between the elevated road and Tsuen Wan Line.
|
|
2003
|
The area between the elevated
road and MTR lines was cleared in 1994 for development. A hard surface was
provided in 1999. Slip roads were constructed on Kwai Chung Road (1995-1996).
A Public Works Regional Laboratory of Civil Engineering and Development
Department was built along the Container Port Road South.
|
|
2008
|
No further significant changes
since 1999.
|
6.9.4
Various HKSAR Government
Departments, listed below, were approached on the historical land use, chemical
storage, and accident records for further identify the potential land
contamination of the Site.
· Lands Department (LandsD) - To
further understand the historical land use and retrieve the past records of
land contamination issues of the Premise, information request letter was sent
to LandsD on 31 October 2013. Written reply from LandsD on 3 December 2013
stated that no contamination was recorded. The letters are present in Appendix 6-3.
· Environmental Protection
Department (EPD) - Letters were sent to EPD to identify the historical records
of chemical spillage / leakage as well as the records of registered chemical
waste producer, respectively, on 31 October 2013. Written reply from EPD on 22
November 2013 stated that there was no record for chemical spillage / leakage
accident of the Site. There was one registered chemical waste producer near the
proposed flyover and widening in Tsuen Wan Road. The letters are present in Appendix 6-3. Table 6-5 shows the list of registered chemical producer in the
nearby areas.
· Fire Services Department (FSD) -
To identity the registration records of Dangerous Goods and the historical records
of dangerous goods spillage / leakage, letter was sent to FSD on 31 October
2013. Written reply from FSD on 15 November 2013 reported there are neither
records of dangerous goods licence nor incident of spillage / leakage of
dangerous goods at the Site. The letters are present in Appendix 6-3.
Table 6-5 List of Registered Chemical Waste
Producers
|
Waste Producers
|
Address
|
Nature of Business
|
Major Chemical Waste Type
|
|
Director of Civil Engineering
(Public Works Regional Laboratory of Tsuen
Wan)
|
Container Port Road South, Kwai Chung, N.T.
|
Material Testing
|
Methylene Chloride
|
Description
of Existing Environment
6.9.5
From the detailed walk over site
survey on 7 November 2013 and from historical records, the Public Works
Regional Laboratory of Tsuen Wan (Laboratory) has been identified as a chemical
waste producer, which is a potential contaminated land use within the project
boundary. Figure 6-2 shows the site
boundary of the Laboratory. Details are
summarised in Table 6-6. According
to Figure 6-2, although a part of
the Laboratory Site is out of the project boundary currently, the whole
Laboratory Site is considered in this review as it is possible for the whole
Laboratory Site to be occupied as a single land lot during construction as
works area.
6.9.6
Another site walk over the
Laboratory Site was conducted on 28 November 2013.The Laboratory Site is
located at Container Port Road South and under Tsuen Wan Road. There were three
nos. of single storey buildings within Laboratory Site. The whole site is
concrete paved. There are storage of fresh and waste Methylene Chloride in the
Dangerous Goods Store and Chemical Waste Storage Room, respectively. Stain was
found on the paved ground at the entrance of the Chemical Waste Storage Room.
There is a transformer on the Laboratory Site but no emergency power generator
was found. The Site Walkover Checklist and Photographs are shown in Appendix 6-4.
Table 6-6 Potentially Contaminative Land Use along
the Site
|
No
|
Potentially
Contaminative Land Use
|
Location
|
|
1
|
Public
Works Regional Laboratory of Tsuen Wan
|
Container
Port Road South
|
Implications
for Road Development
6.9.7
The Laboratory Site is
currently allocated to CGE/Standards & Testing, CEDD. As stated in Section 2.9.9, temporary occupation of
the Laboratory Site is required during construction phase for this Project. The
existing laboratory buildings will be demolished and the Laboratory Site will
be reinstated at the expiry of the allocation. The current allocation period of
the land is up to 23 June 2016 and its extension will be subjected to the
commencement of the construction work for this Project. The implementation of
the construction under this Project will tentatively commence in year
2017/2018. According to a memo between LandsD and the allocatee of the
Laboratory Site (i.e. CGE/Standards & Testing, CEDD) dated on 7 June 2012,
the allocatee shall ensure the Laboratory Site is free from contamination and
in event of land contamination found on the Laboratory Site, the allocatee will
be responsible to carry out the remediation works to remove all the
contaminants from the Laboratory Site at the expiry of the allocation. The memo
is presented in Appendix 6-5.
6.9.8
The Laboratory has been
identified as a chemical waste producer, which is a potential contaminated land
use within the project boundary. The allocatee shall be responsible for the
land contamination assessment of the Laboratory Site and ensure the Laboratory
Site is free from contamination at the expiry of allocation and therefore any
land contamination concern arising from past activities would have been
remediated prior to the construction of the works.
6.9.9
With implementation of good
site practice, land contamination at the Site arising from construction and
operation phases of the Project as road upgrading works is not envisaged.
6.9.10
Thus no adverse environmental
impacts on land contamination for the Project are anticipated.
6.10.1
The Project is likely to result
in the generation of a variety of wastes and require the management and
disposal of inert C&D material, C&D waste, marine sediment, chemical
waste and general refuse during construction phase. It is not expected for
waste generation during operation phase. Provided that the wastes are managed
using approved methods described above, no unacceptable adverse environmental
impacts will be envisaged.
6.10.2
The mitigation measures
recommended in this Chapter should be incorporated into a WMP and applied
through the contract documents to ensure that environmental nuisance does not
arise.
6.10.3
The Laboratory has been
identified as a chemical waste producer, which is a potential contaminated land
use within the project boundary. The allocatee shall be responsible for the
land contamination assessment of the Laboratory Site and ensure the Laboratory
Site is free from contamination at the expiry of allocation and therefore any
land contamination concern arising from past activities would have been
remediated prior to the construction of the works.
6.10.4
With implementation of good
site practice, land contamination at the Site arising from construction and
operation phases of the Project as road upgrading works is not envisaged.
6.10.5
No adverse environmental
impacts on land contamination for the Project are anticipated.
[1] Ove Arup & Partners Hong Kong Ltd
(2008). Agreement No. FM 01/2007 – Review of Options for Management of
Contaminated Sediment in Hong Kong. Final Report (Rev A). August 2008.
[2] Environment
Canada (EC). (1995) Demonstration Project
of a Physico-Chemical Treatment Process
of Contaminated Sediment at the Port of Sorel. St. Lawrence Technologies
- Contaminated Sediment. Ministry of the Environment. EM 1-17/23- 1995.
[3] Federal Remediation Technologies Roundtable
(FRTR). (2001) Abstract of Remediation Case Studies. Member Agencies of the
Federal Remediation Technologies Roundtable, Volume 5, EPA 542-R-01-008, May
2001.
[4] Francingues, N. R., and Thompson, D. W.
(2000) Innovative Dredged Sediment Decontamination and Treatment Technologies.
ERDC TN-DOER-T2, DOER Technical Report, Engineer Research and Development
Center, U.S. Army Corps of Engineers.
[5] Michael R. Palermo (1997), “Integrated
Sediment Decontamination for the New York/New Jersey Harbor”, Proceedings
Cincinnati, OH May 13-14, 1997, National Conference on Management and Treatment
of Contaminated Sediments, United States Environmental Protection Agency,
Office of Research and Development Washington, DC.
[6] EPD, Environmental Impact Assessment on
South Island Line (East), 2014, Available from: http://www.epd.gov.hk/eia/english/alpha/aspd_542.html