4                                       WASTE MANAGEMENT IMPLICATIONS

4.1                                 Introduction

4.1.1.1                     Waste management would be the Contractor’s responsibility to ensure that all wastes produced during the construction phase of the STF are handled, stored and disposed of in accordance with good waste management practices and the relevant regulations and requirements.

4.1.1.2                     Waste materials generated from construction activities, such as construction and demolition (C&D) materials and general refuse, are recommended to be audited at regular intervals (at least once per week as part of the regular site inspections described in Section 9 of this Manual) to ensure that proper storage, transportation and disposal practices are being implemented.  The Contractor would be responsible for the implementation of the mitigation measures to minimize waste or redress problems arising from the waste materials.

4.1.1.3                     Besides, during operational phase of the Project, the EIA Report recommended that the incineration by-products should be tested in accordance with the requirements of the proposed Incineration Residue Pollution Control Limits as recommended in Table 5.2 of the EIA Report prior to disposal to landfill.  A number of the land contamination preventive measures are also recommended in the EIA Report for the operation of the Project.

4.2                                 Waste Management and Control

4.2.1                           Construction Phase

4.2.1.1                     Mitigation measures for waste management as recommended in the EIA Report are summarised below. With proper handling, storage and disposal of waste arisings during the construction phase of the Project, the potential to cause adverse environmental impacts would be minimized.   

Good Site Practices

4.2.1.2                     Adverse impacts related to waste management are not expected to arise, provided that good site practices are strictly followed.  Recommendations for good site practices during the construction activities include the followings:-

l          Nomination of an approved person, such as a site manager, to be responsible for good site practices, including arrangements for collection and effective disposal to an appropriate facility, of all wastes generated at the site;

l          Training of site personnel in proper waste management and chemical handling procedures;

l          Provision of sufficient waste disposal points and regular collection of waste;

l          Appropriate measures to minimize windblown litter and dust during transportation of waste by either covering trucks or by transporting wastes in enclosed containers;

l          Regular cleaning and maintenance programme for drainage systems, sumps and oil interceptors;

l          Proper storage of general refuse in enclosed bins or compaction units, separated from C&D material; and

l          Employment of a reputable waste collector for removal of general refuse from the site, separated from C&D material. 

Waste Reduction Measures

4.2.1.3                     Good management and control can prevent the generation of a significant amount 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 the followings:-

l          The design of the foundation works should minimize the amount of excavated material to be generated;

l          Excavated soil should be reused on site as far as possible, e.g. for landscape works, in order to minimize the amount of public fill to be disposed off-site;

l          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;

l          Encourage collection of aluminium cans by individual collectors by providing separate labelled bins to enable this waste to be segregated from other general refuse generated by the work force;

l          Proper storage and site practices to minimize the potential for damage or contamination of construction materials; and

l          Plan and stock construction materials carefully to minimize amount of waste generated and avoid unnecessary generation of waste.

4.2.1.4                     In addition to the above measures, specific mitigation measures are recommended below for the identified waste so as to minimize environmental impacts during handling, transportation and disposal of the waste.

Waste Management Plan

4.2.1.5                     Waste materials generated from construction activities, such as construction and demolition (C&D) materials and general refuse, are recommended to be audited at regular intervals (at least once per week as part of the regular site inspections described in Section 9 of this Manual) to ensure that proper storage, transportation and disposal practices are being implemented. 

4.2.1.6                     A Waste Management Plan (WMP), which becomes part of the Environmental Management Plan (EMP), shall be prepared to describe the arrangement for avoidance, reuse, recovery and recycling, storage, collection, treatment and disposal of different categories of waste to be generated from the construction activities of the Project. 

4.2.1.7                     A WMP should be developed by the Contractor and submitted to the Site Officer for approval.  The WMP should be prepared and implemented in accordance with ETWB TCW No.19/2005.

4.2.1.8                     A recording system for the amount of wastes generated, recycled and disposed (including the disposal sites) should be adopted.

4.2.1.9                     In order to monitor the disposal of C&D material at public filling facilities and landfills and to control fly-tipping, a trip-ticket system should be adopted (refer to ETWB TCW No.31/2004).

Management of Chemical Wastes 

4.2.1.10                 If chemical wastes are to be produced at the construction site, the Contractor would be required to register with the EPD as a Chemical Waste Producer and to follow the guidelines 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, and incompatible chemicals should be stored separately.  Appropriate labels should be securely attached on each chemical waste container indicating the corresponding chemical characteristics of the chemical waste (such as explosive, flammable, oxidizing, irritant, toxic, harmful, or corrosive). 

4.2.1.11                 The Contractor should use a licensed collector to transport and dispose of the chemical wastes, to either the Chemical Waste Treatment Centre at Tsing Yi, or another licensed facility, in accordance with the Waste Disposal (Chemical Waste) (General) Regulation.

4.2.2                           Operation Phase

4.2.2.1                     The following measures are recommended for the storage, handling and collection of the incineration by-products:-

l          Ash should be stored in storage silos;

l          Ash should be handled and conveyed in closed systems fully segregated from the ambient environment;

l          Ash should be wetted with water to control fugitive dust, where necessary; and

l          The wetted ash should be transported in covered trucks or containers to the designated landfill site.

4.2.2.2                     The STF Contractor should provide the Special Waste and Landfill Restoration Group of EPD with chemical analysis results of the incineration ash and flue gas cleaning residue to confirm that the ash/residue can comply with the proposed incineration residue pollution control limits prior to disposal to WENT landfill.

4.2.2.3                     The EIA Report recommended that Toxicity Characteristic Leaching Procedure (TCLP) tests to be carried out for each batch of fly ash and bottom ash collected in the ash silo at the initial stage of the STF operation (i.e. for a period of 6 months).  If the test results confirm that heavy metals or pH are not of concern, the TCLP test can be deleted or reduced to half-yearly intervals.  It was also recommended that TCLP tests to be carried out for each batch of flue gas cleaning residue stored in the residues silo during the initial stage of the STF operation to confirm whether pre-treatment such as solidification and chemical stabilization would be required to enable the residue to comply with the leachability criteria. 

4.3                                 Approaches to Prevent Land Contamination

4.3.1                           Fuel Oil Spillage Prevention and Handling

4.3.1.1                     Precautionary measures to prevent fuel oil spillage are presented below.

Fuel Oil Tank Construction and Test

l          The fuel tank to be installed should be of specified durability.

l          Double skin tanks are preferred.

l          Underground fuel storage tank should be placed within a concrete pit.

l          The concrete pit shall be accessible to allow regular tank integrity tests to be carried out at regular intervals.

l          Tank integrity tests should be conducted by an independent qualified surveyor or structural engineer.

l          Any potential problems identified in the test should be rectified as soon as possible.

 

Fuel Oil Pipeline Construction and Test

l          Installation of aboveground fuel oil pipelines is preferable; if underground pipelines are unavoidable, concrete lined trenches should be constructed to contain the pipelines.

l          Double skin pipelines are preferred.

l          Distance between the fuel oil refuelling points and the fuel oil storage tank shall be minimized.

l          Integrity tests for the pipelines should be conducted by an independent qualified surveyor or structural engineer at regular intervals.

l          Any potential problems identified in the test should be rectified as soon as possible.

 

Fuel Oil Leakage Detection

l          Installation of leak detection device at storage tank and pipelines.

l          Installation and use of pressure gauges (e.g. at the two ends of a filling line) in fuel filling, which allows unexpected pressure drop or difference and sign of leakage to be detected.

 

Fuel Oil Storage Tank Refuelling

l          Storage tank refuelling (from road tanker) should only be conducted by authorized staff of the oil company using the company’s standard procedures.

 

Fuel Oil Spillage Response

l          An Oil Spill Response Plan should be prepared by the operator to document the appropriate response procedures for oil spillage incidents in details.  General procedures to be taken in case of fuel oil spillage are presented below.

Training

-     Training on oil spill response actions should be given to relevant staff.  The training shall cover the followings:-

w          Tools & resources to combat oil spillage and fire, e.g. locations of oil spill handling equipment and fire fighting equipment;

w          General methods to deal with oil spillage and fire incidents;

w          Procedures for emergency drills in the event of oil spills and fire; and

w          Regular drills shall be carried out.

 

Communication

-     Establish communication channel with Fire Services Department (FSD) and EPD to report any oil spillage incident so that necessary assistance from relevant department can be quickly sought.

Response Procedures 

-     Any fuel oil spillage within the STF site should be immediately reported to the Plant Manager with necessary details including location, source, possible cause and extent of the spillage.

-     Plant Manager should immediately attend to the spillage and initiate any appropriate action to confine and clean up the spillage.  The response procedures shall include the following:

-     Identify and isolate the source of spillage as soon as possible.

-     Contain the oil spillage and avoid infiltration into soil/ groundwater and discharge to storm water channels.

-     Remove the oil spillage.

-     Clean up the contaminated area.

-     If the oil spillage occurs during storage tank refuelling, the refuelling operation should immediately be stopped.

-     Recovered contaminated fuel oil and the associated material to remove the spilled oil should be considered as chemical waste.  The handling and disposal procedures for chemical wastes are discussed in the following paragraphs.

4.3.2                           Chemicals and Chemical Wastes Handling & Spillage Prevention

4.3.2.1                     The precautionary measures to prevent improper handling/ use of chemicals and chemical waste spillage are presented below.

Chemicals and Chemical Wastes Handling & Storage

l          Chemicals and chemical wastes should only be stored in suitable containers in purpose-built areas.

l          The storage of chemical wastes should comply with the requirements of the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes.

l          The storage areas for chemicals and chemical wastes shall have an impermeable floor or surface.  The impermeable floor/ surface shall possess the following properties:-

-     Not liable to chemically react with the materials and their containers to be stored;

-     Able to withstand normal loading and physical damage caused by container handling;

-     The integrity and condition of the impermeable floor or surface should be inspected at regular intervals to ensure that it is satisfactorily maintained;

-     For liquid chemicals and chemical wastes storage, the storage area should be bunded to contain at least 110% of the storage capacity of the largest containers or 20% of the total quantity of the chemicals/chemical wastes stored, whichever is the greater;

-     Storage containers shall be checked at regular intervals for their structural integrity and to ensure that the caps or fill points are tightly closed; and

-     Chemical handling shall be conducted by trained workers under supervision.

Chemicals and Chemical Wastes Spillage Response 

l          A Chemicals and/ or Chemical Wastes Spillage Response Plan shall be prepared by the operator to document in details the appropriate response procedures for chemicals or chemical wastes spillage incidents.  General procedures to be undertaken in case of chemicals/ chemical waste spillages are presented below.

Training

-     Training on spill response actions should be given to relevant staff.  The training shall cover the followings:-

w          Tools & resources to handle spillage, e.g. locations of spill handling equipment;

w          General methods to deal with spillage; and

w          Procedures for emergency drills in the event of spills.

Communication

-     Establish communication channel with FSD and EPD to report the spillage incident so that necessary assistance from relevant department can be quickly sought.

Response Procedures 

-     Any spillage within the STF site should be reported to the Plant Manager.

-     Plant Manager shall attend to the spillage and initiate any appropriate actions needed to confine and clean up the spillage.  The response procedures shall include the followings:-

w          Identify and isolate the source of spillage as soon as possible;

w          Contain the spillage and avoid infiltration into soil/ groundwater and discharge to storm water channels (in case the spillage occurs at locations out of the designated storage areas);

w          Remove the spillage; the removal method/ procedures documented in the Material Safety Data Sheet (MSDS) of the chemicals spilled should be observed;

w          Clean up the contaminated area (in case the spillage occurs at locations out of the designated storage areas); and

w          The waste arising from the cleanup operation should be considered as chemical wastes. 

4.3.3                           Incident Record 

4.3.3.1                     After any spillage, an incident report should be prepared by the Plant Manager.  The incident report should contain details of the incident including the cause of the incident, the material spilled and estimated spillage amount, and also the response actions undertaken.  The incident record should be kept carefully and able to be retrieved when necessary.

4.3.3.2                     The incident report should provide sufficient details for the evaluation of any environmental impacts due to the spillage and assessment of the effectiveness of measures taken.

4.3.3.3                     In case any spillage or accidents results in significant land contamination, EPD should be informed immediately and the STF operator should be responsible for the clean up of the affected area.  The responses procedures described above should be followed accordingly together with the land contamination assessment and remediation guidelines stipulated in the Guidance Manual for Use of Risk-based Remediation Goals for Contaminated Land Management and the Guidance Note for Contaminated Land and Remediation.