This section presents the management and disposal strategy of the
wastes generated from the construction and operational phases of the proposed
Wholesale Fish Market at Tuen Mun Area 44. It is based upon the waste management
principle of reducing the amount of waste requiring final disposal through the
development.
(i)
Construction Phase
7.1.1 The construction works of the subject development mainly include foundation work and superstructure construction. The estimated periods for the foundation work and superstructure construction are 9 months and 17 months respectively.
7.1.2 Since the existing land uses at the subject site are mainly open area and temporary car parks, the demolition waste is limited. The majority of solid waste originates from the soil excavation and removal from piling activities of the foundation works. The estimated quantity of soil to be removed is approximately 3,000 to 5,000 cubic meters.
7.1.3 A few cubic meters of chemical waste such as lubricants and thinners will be generated throughout the whole construction period.
Wooden boards for moulding and spent concrete during concreting of piles or pile-cap and superstructures is a possible source of solid waste generation, reusable steel hoarding and covered walkways will be employed, minimal amount of solid waste generation from hoarding works is anticipated.
7.1.4 The types, quantities and time period of wastes generated during the construction phase are estimated in Table 7.1.
Table 7.1 Details of Waste Generation during Construction Phase
|
Construction Period |
Type of Waste |
Quantity |
|
Foundation work |
Excavated soil |
3,000 – 5,000 m3 |
|
Foundation work & superstructure construction |
Wooden board Spent concrete Steel Chemical waste (lubricants and thinners) |
900m3 1,200m3 900m3 ~ 5m3 |
7.1.5 The disposal options and quantities of
construction waste to be disposed of off-site or reused/recycled are estimated
in Table 7.2. It is assumed that 25% of the excavated soil, spent concrete,
steel and timber can be reused or recycled.
Table 7.2 Quantity of Construction Waste for
Off-Site Disposal or Reuse/Recycle
|
Disposal Options |
Type of Waste |
Quantities |
|
Off-site disposal at landfills |
Timber, steel |
1,350 m3 |
|
Off-site disposal at public fill |
Excavated soil, spent concrete |
3,900 m3 |
|
Chemical Waste Treatment Centre |
Lubricants, thinners |
~5m3 |
|
Reuse/recycle |
Excavated soil, spent concrete, steel and timber |
1,750 m3 |
(i)
Operational Phase
7.1.6 The details of waste generation during the operation of the proposed development, are shown in Table 7.3. Trade waste and municipal waste are generally generated. No hazardous waste is anticipated during the operational phase.
Table 7.3 Details of Waste Generation during Operational Phase
|
Proposed Facilities |
Type of Waste |
Quantity |
|
Wholesale Fish Market |
-
Paper/newspaper and dead fish contained in foam boxes -
Sewage discharge |
-
0.14 m3/day* -
5.4 m3/daya |
|
Community Hall |
General
domestic waste |
1.6kg/capita/day1 |
|
Other Possible
Community Uses |
Paper and clear
plastic bottles |
10 kg/day* |
|
RCP |
Municipal solid
waste |
13,200
litres/day* |
|
Marine RCP |
Polyfoam,
timber and plastic bags |
3 tonnes/day* |
a Assume 70% of total water consumption (7.7m3/day) will be
discharged.
*Information
provided by relevant Government Departments.
The details of the waste handling of the RCP and MRCP are shown in Table 4.
Table 7.4 Details of Waste Handling of the RCP and MRCP
|
Facilities |
Type of Waste |
Operation Period |
Quantity |
|
RCP |
Newspaper,
plastic bag and foam box |
07:00 – 08:00 |
80kg/day |
|
MRCP |
Polyfoam, timber
and plastic bag |
08:00 – 18:00 |
3 tonnes/day |
Information provided by relevant
Government Departments.
The general approach of the waste management includes elimination, reduction, reuse, treatment and disposal of waste. In this section, waste management practices are introduced in order to minimise the amount of waste to be generated and maximise the reuse of materials.
(i) Construction
Phase
7.2.1 During construction phase, various types of construction waste in the form of wastewater, solid waste such as vegetation, soil and plywood, and chemical waste such as lubricant and thinner will be produced. The following the general good site practice and waste management:
(a)
Reusable materials such as metallic board for formworks can be considered
to avoid the use of plywood, which is less reusable and durable.
(b)
Garbage from office and site workers will be segregated from
construction waste and will be contained and disposed of to proper refuse
collection point. Recyclable materials such as waste paper from clerical works,
plastic bottles and aluminium cans can be segregated and sent to proper waste
collectors for recycling.
(c)
The recommended construction waste management strategy is to segregate
the inert and non-inert portions of waste.
The inert portion, including excavated soil, will be disposed of at a
public fill. The construction of the proposed WFM would require the preparation
of a Waste Management Plan (WMP) prior to the commencement of the construction
works. The site of the public fill should be identified when preparing the WMP.
The non-inert portion of waste should be reused/recycled whenever
possible. Disposal of the non-inert
portion of waste to landfill site should be considered as the last resort.
(d)
During the construction works, one should register as chemical waste
producer with EPD if chemical waste is produced and chemical waste should be
collected by licensed a collector. Disposal of chemical waste such as
lubricants and thinners will be handled in accordance with the Code of Practice
on the Packaging, Labelling and Storage of Chemical Wastes published under the
WDO Section 35.
7.2.2 In order to minimise the generation
of construction waste, specific mitigation measures should be adopted during
the design and construction stages
to minimise the waste generation.
Planning
& Design Stages
·
Minimise required excavation of
soil and material used during the design of foundation structure &
superstructure.
·
Evaluate the potential of re-using
of excavated soils for back-filling and landscaping
purposes.
·
Design and provide an area within
the construction site to allow on-site sorting and segregation of waste
materials.
Construction
Stage
·
Segregate all reusable and
recyclable waste materials and store in different containers, skips or stockpiled.
·
Separate inert construction
materials for either re-use on-site or dispose of at public fill.
·
Provide temporary storage areas for
storing and stockpiling reusable and recyclable materials.
·
Provide training to site staff
about waste minimisation practices
including waste reduction, reuse and recycling.
The
following mitigation measures should also be adopted for managing the disposal
of construction material:
·
Separate the inert and non-inert
portions of construction material for disposal of public fill and landfill respectively.
·
Employ approved licensed waste
collectors to collect the inert construction materials to be disposed of at
public fill.
·
Maintain accurate site record
throughout the construction works detailing the quantities of materials generated on site, reused on site,
disposed off-site together with disposal routes/locations.
·
Monitor the disposal of
construction waste at public fills and landfills, and control free-tipping
by a trip-ticket system. Reference should be made to WBTC No.5/99 “Trip-ticket System for Disposal
of Construction and Demolition Material”.
Waste Management Plan
7.2.3 A Waste Management Plan (WMP) will
be included in the building contract in accordance with the Works Bureau
Technical Circular No. 29/2000 to set out the
disposal strategy and waste management practice for the following:
·
minimise potential adverse impacts
associated with waste arising from the construction activities
·
implement the aforementioned
proposed mitigation measures properly and effectively.
·
The WMP is to be submitted to the Architect for approval and
proper implementation by the contractor during the construction phase. The
Contractor shall review the WMP at monthly intervals and shall submit a revised
and updated WMP if necessary.
(ii) Operational Phase
7.2.4 Waste generation sources originate from the operation of the wholesale fish market, community hall, public toilets, management offices and other possible community uses. Waste in the form of wastewater will be discharged to public sewer and solid waste will be gathered at the RCP.
(a) Solid waste generated from the fish market includes dead fish, plastic bags and polyfoam boxes. Unlike dead fish, plastic bags are difficult to decompose in the landfill. In order to minimise the amount of waste disposal, reusable containers can be used instead of plastic bags. As advised by AFCD, fishermen and fish traders reuse the polyfoam boxes as many times as possible until they are broken. In addition, FMO has liaised with a company to collect broken polyfoam boxes for recycle, therefore, mitigation measures for polyfoam waste generation are unlikely to be required. The design should allow for separation and suitable storage of broken polyfoam casings prior to collection.
(b) Municipal solid waste generated from community hall, offices and other possible community uses will be segregated. Reuse of materials will be practised, as for example single-sided paper for rough works, as much as possible within the subject development. Any recyclable and reusable materials will be collected and sent to waste collectors for regeneration.
(c) It is anticipated that the dead fish will not cause significant adverse impact since only a small amount of dead fish (0.14m3/day) will be generated and the dead fish will be disposed of at nearby RCP and dispatched for final disposal everyday from the RCP. The dead fish will not be kept for a long time at the WFM complex. Nevertheless, in order to minimise the potential odour and health problem, it is recommended that the dead fish should be kept in a sealed durable and reusable container before being wrapped in plastic for daily disposal at the adjacent RCP.
1 Howard S. Peavy, Donald R. Rowe & George Tchobanoglous, Environmental Engineering, Table 11-2, McGraw Hill Book Company, 1985