9                            WASTE Management and Land Contamination

9.1                     Introduction

9.1.1.1              The construction of the Trunk Road T2 will involve a number of activities which will generate waste that can be broadly be classified into distinct categories based on its nature and the options for disposal. These include:

·             Excavated marine deposit (sediment) buried underneath the South Apron and Cha Kwo Ling works areas for the construction of cut-and-cover tunnel sections;

·             Excavated C&D materials suitable for public fill, including the alluvium from the sub-marine tunnel construction;

·             C&D waste which is not suitable for public fill;

·             Chemical waste;

·             Sewage; and

·             General refuse.

9.1.1.2              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.

9.1.1.3              Large quantities of wastes are not expected to be generated from the operational phase of the Trunk Road T2 project 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.

9.2                     Mitigation Measures

9.2.1                   Waste Management

9.2.1.1              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. 

9.2.1.2              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 future contractor as appropriate; 

(ii)               The future contractor should be requested to submit an outline Waste Management Plan (WMP) 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 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 future 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 spoil volumes to be generated and the Public Fill Committee (PFC) should be notified and agreement sort on the disposal of surplus inert C&D materials e.g. good quality rock during detailed design of the Trunk Road T2 Project.  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 extent of cutting operation should be optimised where possible. Earth retaining structures and bored pile walls should be proposed to minimise the extent of cutting;

(viii)          Inert C&D materials from road pavement would be reused for backfilling where possible;

(ix)              TBM generated alluvium and other C&D materials should be treated at a slurry treatment plant prior to transferring to Public Fill Reception Facilities;

(x)                The site and surroundings should be kept tidy and litter free;

(xi)              No waste is allowed to be burnt on site;

(xii)            Make provisions in contract documents to allow and promote the use of recycled aggregates where appropriate;

(xiii)          Prohibit the future contractor to dispose of C&D materials at any sensitive locations e.g. natural habitat, etc.  The future contractor should propose the final disposal sites in the WMP for approval before implementation;

(xiv)          Stockpiled C&D materials should be covered by tarpaulin and/or watered as appropriate to prevent windblown dust and surface run off;

(xv)            Excavated C&D materials in trucks should be covered by tarpaulins to reduce the potential for spillage and dust generation;

(xvi)          Wheel washing facilities should be used by all trucks leaving the site to prevent transferring mud trails onto public roads;

(xvii)        Excavated marine deposit (sediment) should be disposed of in a gazetted marine disposal ground under the requirements of the DASO or treated for backfilling;

(xviii)      Standard formwork or pre-fabrication should be used as far as practicable 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; 

(xix)          The future 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;

(xx)            All falsework should be steel instead of wood as far as practicable;

(xxi)          Chemical waste producers should register with the EPD and 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;

(xxii)        Waste oils, chemicals or solvents should not be disposed of to drain;

(xxiii)      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;

(xxiv)       General refuse arising on-site should be stored in enclosed bins or compaction units separately from C&D and chemical wastes.  Sufficient dustbins should be provided for storage of waste as required under the Public Cleansing and Prevention of Nuisances By-laws.  In addition, general refuse should be cleared daily and disposed of to the nearest licensed landfill.  Burning of refuse on construction sites is prohibited;

(xxv)         All waste containers should be in a secure area on hardstanding;

(xxvi)       Aluminium cans should be collected and recovered from the waste stream by reputable collectors if they are segregated and easily accessible.  Separately labelled bins for their deposition should be provided as far as practicable;

(xxvii)     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 future contractor should be advocated.  Waste separation facilities for paper, aluminium cans, plastic bottles, etc should be provided on-site; and

(xxviii)   Training should be provided to workers about the concepts of site cleanliness and appropriate waste management procedure, including waste reduction, reuse and recycling. 

9.2.1.3              The recommended disposal sites for the different types of waste are detailed in Table 9.1 below:

Table 9.1    Recommended Waste Disposal Sites

Type of Waste

Disposal Site

Marine Deposit (Sediment) (1)

On-site backfilling after treatment

C&D materials

Tseung Kwan O Area 137 Fill Bank and Chai Wan Public Fill Barging Point

C&D waste (plastics, glass, wood, including cleared vegetation etc.)

SENT Landfill

Chemical waste (as defined under Schedule 1 of the Waste Disposal (Chemical Waste) Regulation)

Chemical Waste Treatment Centre in Tsing Yi or other approved facilities

General refuse

SENT Landfill

Note (1): Agreement from relevant parties (e.g. Marine Fill Committee (MFC), Public Fill Committee (PFC) and Waste Policy and Science Group of EPD, etc) will be sought for the above proposal as appropriate.  Otherwise, the ETWB TC(W) No.34/2002 will be followed for the proper handling and disposal of the sediments accordingly (refer to Section 11.4.2 of the EIA Report).  Excavation work would not proceed until all issues on management of dredged/excavated sediments have been resolved and all relevant arrangements have been endorsed by the relevant authorities including the MFC, PFC and EPD.

9.2.2                 Land Contamination

9.2.2.1              As there were no predicted exceedances of the collected soil and groundwater samples in the SI, no specific mitigation measures for land contamination are required. There are remaining SI works at borehole locations EH1 and EH3 and further reconnaissance visits to inaccessible Works Area WA2 to be conducted when these sites become accessible.  Supplementary CAP, CAR and/or RAP and RR (if remediation work is necessary) should be submitted to EPD for endorsement before commencement of construction works at these sites.

9.3                     EM&A Requirements

9.3.1                   Waste Management

9.3.1.1              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. 

9.3.1.2              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:

l  to ensure the waste arising from the works are handled, stored, collected, transferred and disposed of in an environmentally acceptable manner;

l  verify the implementation status and evaluate the effectiveness of the mitigation measures; and

l  to encourage the reuse and recycling of material.        

9.3.1.3              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

9.3.1.4              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. 

9.3.1.5              The Contractor’s waste management practices should be audited with reference to the checklist detailed in Table 9.2 below.

Table 9.2    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

9.3.2                   Land Contamination

9.3.2.1              As no specific mitigation measures are required for land contamination, no EM&A would be required. However, there are remaining SI works at borehole locations EH1 and EH3 and further reconnaissance visits to inaccessible Works Area WA2 to be conducted when these sites become accessible.  Supplementary CAP, CAR and/or RAP and RR (if remediation work is necessary) should be submitted to EPD for endorsement before commencement of construction works at these sites.