5.      WASTE MANAGEMENT

Introduction

5.1              Waste management will be the contractor’s responsibility to ensure that all wastes produced during the upgrading works for the TPSTW are handled, stored and disposed of in accordance with good waste management practices and EPD’s regulations and requirements.

5.2              The main waste material generated during construction activities was identified to be construction and demolition (C&D) material and was recommended to be audited at regular intervals (at least monthly) to ensure that proper storage, transportation and disposal practices were implemented.  The monitoring of waste management practices would ensure that these solid wastes generated during construction would not be disposed into the nearby coastal waters. The Contractor would be responsible for the implementation of any mitigation measures to minimise waste or redress problems arising from the waste materials.

Waste Control and Mitigation Measures

Construction Phase

5.3              Mitigation measures for waste management are summarised below. With the appropriate handling, storage and removal of waste arisings during the construction phase as defined below, the potential to cause adverse environmental impacts would be minimised.  The implementation schedule of the recommended mitigation measures is presented in Appendix B.

            Good Site Practices and Waste Reduction Measures

5.4              Appropriate waste handling, transportation and disposal methods for all waste arisings generated during the construction works at the TPSTW shall be implemented to ensure that construction wastes do not enter the nearby coastal waters of Tolo Harbour.

5.5              It is expected that adverse impacts from waste management would not arise, provided that good site practices are strictly followed.  Recommendations for good site practices during construction include:

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

·           training of site personnel in site cleanliness, appropriate waste management procedures, including chemical waste handling procedures, and concepts of waste reduction, reuse and recycling;

·           provision of sufficient waste disposal points and regular collection for disposal;

·           appropriate measures to minimise windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers;

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

·           a Waste Management Plan shall be prepared and shall be submitted to the Engineer for approval.  One may make reference to ETWB TCW No. 15/2003 for details; and

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

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

5.7              Good management and control can prevent the generation of significant amounts of waste.  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;

·         separate labelled bins shall be provided to segregate aluminium cans from other general refuse generated by the work force, and to encourage collection of aluminium cans by individual collectors;

·         any unused chemicals or those with remaining functional capacity shall be recycled;

·         maximising 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; and

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

5.8              In addition to the above good site practices and waste reduction measures, specific mitigation measures are recommended below for the identified waste arisings to minimise environmental impacts during handling, transportation and disposal of these wastes. 

            General Refuse

5.9              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.

            Construction and Demolition Material

5.10          The C&D material generated from the site formation and demolition works shall be sorted on-site into inert C&D material (that is, 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, it is recommended that the excavated material comprising fill material 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.  The stockpiling/sorting area shall be located as far away as possible from the identified NSR of the TPSTW Staff Quarters.

            Bentonite Slurry

5.11          Bentonite slurries used in construction works shall be reconditioned and reused wherever practicable.  Residual used bentonite slurry shall be disposed of from the site as soon as possible as stipulated in Clause 8.56 of the General Specification for Civil Engineering Works which states “Bentonite slurry which will not be reused shall 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.

Chemical Wastes

5.12          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.  Good quality containers compatible with the chemical wastes should be used.  Appropriate labels should be securely attached on each chemical waste container indicating the chemical characteristics of the chemical waste, such as explosives, flammable, oxidizing, irritant, toxic, harmful, corrosive, etc.  Any specific requirements regarding the disposal of spent UV lamps would be specified by EPD following the provision of design information of the UV disinfection system at the detailed design stage (should this disinfection option be selected).  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.