2                                  AIR QUALITY

2.1                           Introduction

2.1.1.1                The EIA study of the Trunk Road T2 Project concluded that, with the implementation of the dust suppression measures stipulated in the Air Pollution Control (Construction Dust) Regulation, good site practices and proposed mitigation measures, adverse dust impact would not be anticipated at the Air Sensitive Receivers (ASRs) as shown in Figure 2.1 in the vicinity of the construction sites. As such, dust monitoring is not recommended.

2.1.1.2                However, weekly site audits are recommended to ensure that appropriate dust control measures are properly implemented and good construction site practices are adopted throughout the construction period.

2.1.1.3                During the operation phase, air quality monitoring of this Trunk Road T2 project is considered not necessary as the Project would not be expected to generate any air quality impacts to the adjacent identified ASRs.

2.2                           Monitoring Requirements

2.2.1                      Monitoring Parameters and Equipment

2.2.1.1                The levels of total suspended particulate (TSP) should be measured by following the standard method as set out in the High Volume Method for Total Suspended Particulates, Part 50 Chapter 1 Appendix B, Title 40 of the Code of Federal Regulations of the USEPA (the HVS method) or by direct reading methods which are capable of producing comparable results as that by the high volume sampling method.

2.2.1.2                Dust laden in air should be drawn through a high volume sampler (HVS) fitted with a conditioned, pre-weighed filter paper, at a controlled rate.  After sampling for 24-hours, the filter paper with the retained dust particles should be collected and returned to the laboratory for drying in a desiccator followed by weighing.  The 24-hour average TSP levels should be calculated from the ratio of the mass of particulates retained on the filter paper to the total volume of air sampled. 

2.2.1.3                All the relevant data including the temperature, pressure, weather conditions, elapsed-time meter reading for the start and stop of HVS, identification and weight of the filter paper, and other specific phenomena and works progress of the concerned works sites, etc, should be recorded in detail.  A sample data sheet is shown in Appendix B of this EM&A Manual. 

2.2.1.4                The HVS in compliance with the following specifications should be used for carrying out the 1-hour and 24-hour monitoring for TSP levels:

(i)            0.6-1.7m3 per minute (20-60 standard cubic feet per minute) adjustable flow range;

(ii)           Equipped with a timing/control device with ±5 minutes accuracy for 24 hours operation;

(iii)         Installed with elapsed-time meter with ±2 minutes accuracy for 24 hours operation;

(iv)         Capable of providing a minimum exposed area of 406 cm2 (63 square inch);

(v)          Flow control accuracy: ±2.5% deviation over 24-hour sampling period;

(vi)         Incorporated with an electronic mass flow rate controller or other equivalent devices;

(vii)       Equipped with a flow recorder for continuous monitoring;

(viii)      Provided with a peaked roof inlet;

(ix)         Incorporated with a manometer;

(x)          Capable of holding and sealing the filter paper to the sampler housing at horizontal position;

(xi)         Easy to change the filter; and

(xii)       Capable of operating continuously for 24-hour periods.

2.2.1.5                The ET should be responsible for providing the monitoring equipment and should ensure that sufficient HVSs with the appropriate calibration kit are available for carrying out the baseline monitoring, regular impact monitoring and ad-hoc monitoring as required.  The HVSs should be equipped with an electronic mass flow controller and be calibrated against a traceable standard at regular intervals, in accordance with the requirements in the manufacturer’s operating manual and as described below.  All the equipment, calibration kit, filter papers, etc, should be clearly labelled.

2.2.1.6                The initial calibration of the HVSs with mass flow controller should be conducted upon the installation and thereafter in every 6 months.  The calibration should be conducted using an orifice calibrator and the calibration data should be properly documented for the future reference by the IEC.  The flow rates of the sampler before and after the sampling with the filter in position should be verified to be constant and be recorded on the data sheet as shown in Appendix B.

2.2.2                      Air Sensitive Receivers

2.2.2.1                Dust monitoring during construction phase should be carried out at the identified air sensitive receivers (ASRs) when there is construction works within proximity of the ASRs.

2.2.2.2                ASRs have been identified in accordance with Annex 12 of the EIAO-TM, including domestic premises, hotels, hostels, temporary housing accommodation, hospitals, medical clinics, educational institutions, offices, factories, shops, shopping centres, places of public worship, libraries, courts of law or performing arts centre.

2.2.2.3                The planned developments projects in the Kai Tak Development (KTD) and the Cha Kwo Ling area have been discussed in Section 3 of the EIA Report.  As per the respective Final Recommended Outline Development Plan (RODP) of Kai Tak released on 31 January 2013 and Outline Zoning Plan (OZP) No. S/K22/4 gazetted on 14 September 2012 for the South Apron and OZP S/K15/19 gazetted on 17 June 2011 for the Cha Kwo Ling, Yau Tong and Lei Yue Mun. The Centre of Excellence in Paediatrics (CEP) is a hospital planned to be implemented at the South Apron within 500m of the Trunk Road T2 project boundary.  It is anticipated to be constructed between September 2013 and June 2017 and in operation in mid of 2018 and, thus, would be identified as an future ASR during construction and operational phases.  According to the Revised Technical Feasibility Study (TFS) for Establishment of Centre of Excellence in Paediatrics and Neuroscience and a New Acute Hospital in Kai Tak Airport, revised in July 2011, the preliminary layout plan shows an 8m set back from the site boundary. 

2.2.2.4                While a detailed construction schedule for the Kerry residential development is not available, it has been confirmed that the residential development is due for completion at the end of 2016 and as such would be identified as an ASR for both construction and operational phases.  It is understood that the conditions of the land lease have specified a requirement to provide a 20m wide waterfront promenade along the harbour front side of the site.  However, as the design of the development is not fixed and a waterfront promenade is also an ASR, so the potential setback has not been considered in this assessment.

2.2.2.5                The existing ASRs have been identified with reference to the latest information provided on the survey maps, topographic maps, aerial photos, land status plans and confirmed by various site surveys undertaken. 

2.2.2.6                The relevant stakeholders have also been approached to obtain the latest information on planning application, layout and building height, etc. The major planned uses in the vicinity of the area include the different land uses in the area including Commercial, Comprehensive Development Area, Residential, Government, Institution or Community, Open Space and Other Specified Uses of Kai Tak Future Development.

2.2.2.7                With reference to the EIA Study Brief for the Project (ESB-203/2009), the Study Area for the air quality impact assessment has been defined as a distance of 500 metres from the boundary of the Trunk Road T2 project and from any work sites proposed under the project, and has been extended to include major existing and planned/committed air pollutant emission sources including tunnel portal/ventilation building(s) of the Central Kowloon Route (CKR) and the Tseung Kwan O-Lam Tin Tunnel (TKO-LTT), industrial uses in Kwun Tong and the Kowloon Bay Area.

2.2.2.8                Therefore, the air quality assessment has included ASRs within the site boundary, which may be potentially affected by the Project.  The existing ASRs are industrial buildings, commercial buildings, parks at Kowloon Bay and Kwun Tong and the industrial buildings, residential buildings and sitting area at Cha Kwo Ling.  The planned ASRs are the Commercial, Comprehensive Development Area, Residential, Government, Institution or Community, Open Space and Other Specified Uses of Kai Tak Future Development. The details of the identified relevant ASRs are listed in Table 2.1 and shown in Figure 2.1.

Table 2.1  Relevant Air Sensitive Receivers

ASR No.

Location

KTD 1

Centre of Excellence in Paediatrics

KTD 2

G/IC Zone next to Kwun Tong Bypass (Future Hospital at Site 3C1)

KER 1

Future Residential Development at Kerry Godown

CKL 1

Flat 121 Cha Kwo Ling Village

CKL 2

Flat 103 Cha Kwo Ling Village

 

2.2.2.9                It should be noted that the identified air sensitive receivers (ASRs) may not be occupied at the time construction commences, hence the status and location of the ASRs may change after this EM&A Manual has been issued. 

2.2.3                      Baseline Monitoring

2.2.3.1                The baseline monitoring should be carried out to determine the ambient 1-hour and 24‑hour TSP levels at the monitoring locations prior to the commencement of the main construction works for the Trunk Road T2 project.  Prior to commencing the baseline monitoring, the ETL should inform the IEC of the baseline monitoring programme such that the IEC can conduct the on-site audit to ensure the accuracy of the baseline monitoring results. 

2.2.3.2                The baseline monitoring of TSP levels should be carried out for a continuous period of at least two weeks with the 24-hour and three sets of 1-hour ambient measurements taken daily at each monitoring location.  During the baseline monitoring, there should not be any construction or dust generating activities in the vicinity of the monitoring stations.  The general meteorological conditions (e.g. wind speed, direction and precipitation) and notes regarding any significant adjacent dust producing sources should be recorded throughout the baseline monitoring.  A summary of the requirements for the baseline monitoring is shown in Table 2.2.

Table 2.2            Summary of Construction Dust Monitoring Programme

Monitoring Period

Duration

Parameter

Frequency

Baseline Monitoring

Consecutive days of at least 2 weeks before commencement of construction works

1 hour TSP

3 times per day

Continuous 24-hour TSP

Daily

Impact Monitoring

Throughout the construction phase*

1 hour TSP

3 times per 6 days (as required in case of complaints)

Continuous 24-hour TSP

Once per 6 days

*    Impact monitoring should be conducted at the monitoring stations for 24-hour TSP monitoring when there are project-related construction activities being undertaken within a radius of 500m from these monitoring stations.

2.2.3.3                The baseline monitoring will provide environmental data for the determination of the appropriate Action levels for the air quality monitoring, whilst the Limit levels will be set against the statutory or otherwise agreed limits.  If the ET considers that significant changes in the ambient conditions have arisen, a repeat of the baseline monitoring may be carried out to update the baseline levels and Action levels, upon the consultation and agreement with the ER, IEC and EPD.  

2.2.4                      Impact Monitoring

2.2.4.1                The monthly schedule of the impact construction dust monitoring programme should be drawn up by the ET one month prior to the commencement of the scheduled construction period. 

2.2.4.2                For the regular 24-hour TSP impact monitoring, a sampling frequency of at least once per 6 days should be strictly conducted at the monitoring stations when there are main project related construction activities being conducted within a radius of 500m from these monitoring stations.  In case of complaints, the 1-hour TSP monitoring should be conducted at least three times per 6 days when the highest dust impacts are likely to occur.  The impact monitoring programme is also summarised in Table 2.2 above.

2.2.4.3                Before commencement of the monitoring, the ET should inform the IEC of the impact monitoring programme such that the IEC can conduct an on-site audit to ensure the accuracy of the impact monitoring results.

2.2.5                      Compliance Assessment

2.2.5.1                The Action and Limit (A/L) levels that provide an appropriate framework for the interpretation of monitoring results have to be agreed between the ET, IEC, EPD and ER before the commencement of the construction dust monitoring, and the monitoring data should be checked against these agreed A/L levels.  The recommended A/L levels are summarised in Table 2.3.

Table 2.3:  Action and Limit (A/L) Levels for Construction Dust Impact Monitoring

Parameter

Action Level*

Limit Level

TSP (24 hour average)

BL £ 200 μgm-3, AL = (BL x 1.3 + LL)/2

BL > 200 μgm-3, AL = LL

260 μgm-3

 

TSP (1 hour average)

BL £ 384 μgm-3, AL = (BL x 1.3 + LL)/2

BL > 384 μgm-3, AL = LL

500 μgm-3

* BL = baseline level; AL = Action level; LL = Limit level

2.2.6                      Event and Action Plan

2.2.6.1                The Event and Action Plan prescribes the procedures and action associated with the outcome of the comparison of the construction dust monitoring data recorded and the agreed A/L levels.  In the cases where exceedances of these A/L levels occur, the ET, IEC, ER and Contractor should strictly observe the relevant action of the respective Event and Action Plan as listed in Table 2.4.

Table 2.4    Event and Action Plan for Construction Dust Monitoring

EVENT

ACTION

ET(1)

IEC(1)

ER(1)

Contractor

Action Level

 

 

 

 

1.   Exceedance for one sample

1.   Identify sources, investigate the causes of complaint and propose remedial measures.

2.   Inform IEC and ER.

3.   Repeat measurement to confirm finding;.

4.   Increase monitoring frequency.

1.   Check monitoring data submitted by the ET.

2.   Check the Contractor’s working methods.

1.   Notify the Contractor.

1.   Rectify any unacceptable practices. 

2.   Amend working methods agreed with the ER as appropriate. 

2.   Exceedance for two or more consecutive samples

1.   Identify sources.

2.   Inform the IEC and ER.

3.   Advise the ER on the effectiveness of the proposed remedial measures;

4.   Repeat measurements to confirm findings.

5.   Increase monitoring frequency to daily.

6.   Discuss with the IEC, ER and Contractor on remedial action required.

7.   If exceedance continues, arrange meeting with the IEC, Contractor and ER.

8.   If exceedance stops, cease additional monitoring.

1.   Check monitoring data submitted by the ET.

2.   Check the Contractor’s working methods.

3.   Discuss with the ET, ER and Contractor on possible remedial measures if required.

4.   Advise the ER on the effectiveness of proposed remedial measures if required.

1.   Notify the Contractor.

2.   Ensure remedial measures properly implemented.

1.   Submit proposals for remedial action to the ER within 3 working days of notification. 

2.   Implement the agreed proposals. 

3.   Amend proposal as appropriate. 

Limit Level

 

 

 

 

1.   Exceedance for one sample

1.   Identify sources, investigate causes of exceedance and proposed remedial measures.

2.   Inform the IEC, ER, and Contractor.

3.   Repeat measurement to confirm finding.

4.   Increase monitoring frequency to daily.

5.   Assess effectiveness of the Contractor’s remedial action and keep the IEC and ER informed of the results.

1.   Check monitoring data submitted by the ET.

2.   Check the Contractor’s working methods.

3.   Discuss with the ET, ER and Contractor on possible remedial measures.

4.   Advise the ER and ET on the effectiveness of the proposed remedial measures.

5.   Supervise the implementation of remedial measures.

1.   Confirm receipt of the notification of exceedance in writing.

2.   Notify the Contractor.

3.   Ensure remedial measures are properly implemented.

1.   Take immediate action to avoid further exceedance. 

2.   Submit proposals for remedial action to the ER and copy to the ET and IEC within 3 working days of notification. 

3.   Implement the agreed proposals. 

4.   Amend proposal as appropriate. 

2.   Exceedance for two or more consecutive samples

1.   Notify the IEC, ER and Contractor.

2.   Identify sources.

3.   Repeat measurements to confirm findings.

4.   Increase monitoring frequency to daily.

5.   Carry out analysis of the Contractor’s working procedures with the ER to determine the possible mitigation to be implemented.

6.   Arrange meeting with the IEC and ER to discuss the remedial action to be taken.

7.   Assess the effectiveness of the Contractor’s remedial action and keep the IEC, EPD and ER informed of the results.

8.   If exceedance stops, cease additional monitoring.

1.   Discuss amongst the ER, ET and Contractor on the potential remedial action.

2.   Review the Contractor’s remedial action whenever necessary to assure their effectiveness and advise the ER and ET accordingly.

3.   Supervise the implementation of remedial measures.

1.   Confirm receipt of the notification of exceedance in writing.

2.   Notify the Contractor.

3.   In consultation with the IEC and ET, agree with the Contractor on the remedial measures to be implemented.

4.   Ensure remedial measures are properly implemented.

5.   If exceedance continues, consider what portion of works is responsible and instruct the Contractor to stop that portion of works until the exceedance is abated.

1.   Take immediate action to avoid further exceedance.

2.   Submit proposals for remedial action to the ER and copy to the IEC and ET within 3 working days of notification.

3.   Implement the agreed proposals.

4.   Resubmit proposals if problems still not under control.

5.   Stop the relevant portion of works as determined by the ER until the exceedance is abated.

2.3                           Mitigation Measures

2.3.1.1                Specific mitigation measures have been assumed in the modelling to reduce the dust generation from the Project to within the 1-hour (500µgm-3), 24-hour (260µgm-3) and Annual (80µgm-3) criteria at ASRs, and have been applied for both the short-term Tier 1 and annual TSP predictions.  The specific mitigation comprises the following:

(i)                watering of the construction areas 12 times per day to reduce dust emissions by 91.7%, with reference to the “Control of Open Fugitive Dust Sources” (USEPA AP-42).  The amount of water to be applied would be 0.91L/m2 for the respective watering frequency;

(ii)              Dust enclosures with watering would be provided along the loading ramps and conveyor belts for unloading the C&D materials to the barge for dust suppression; and

(iii)             3-sided barriers around the stockpiling areas WA3 and WA4.

2.3.1.2                In addition to the mitigation mentioned above, under the auspices of the Air Pollution Control (Construction Dust) Regulation, the Contractor will be required to ensure that dust control measures stipulated in the Regulation should be implemented to control dust emissions.  The dust control measures detailed below shall also be incorporated into the Contract Specification where practicable as an integral part of good construction practice:

(i)            Use of regular watering to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather;

(ii)           Use of frequent watering for particularly dusty construction areas and areas close to ASRs;

(iii)         Side enclosure and covering of any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to frequent usage, watering shall be applied to aggregate fines;

(iv)         Open stockpiles shall be avoided or covered. Prevent placing dusty material storage piles near ASRs;

(v)          Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations;

(vi)         Establishment and use of vehicle wheel and body washing facilities at the exit points of the site;

(vii)       Imposition of speed controls for vehicles on unpaved site roads, 8 km per hour is the recommended limit;

(viii)      Routing of vehicles and position of construction plant should be at the maximum possible distance from ASRs;

(ix)         Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides;

(x)          Cement or dry PFA delivered in bulk should be stored in a closed silo fitted with an audible high level alarm which is interlocked with the material filling line and no overfilling is allowed; and

(xi)         Loading, unloading, transfer, handling or storage of bulk cement or dry PFA should be carried out in a totally enclosed system or facility, and any vent or exhaust should be fitted with an effective fabric filter or equivalent air pollution control system.

2.4                           Audit Requirements

2.4.1.1              The implementation of regular site audits aims to ensure the mitigation measures recommended in the EIA report to be properly undertaken during the construction phase of this Project.  It can also provide an effective control of any mal-practices and, therefore, achieve the continual improvement of the environmental performance on-site. 

2.4.1.2              Inspections of the construction activities and works sites and works areas should be conducted by the Contractor at least on a weekly basis to ensure the mitigation measures to be properly implemented.

2.4.1.3              Site audits should be carried out by the Engineer, ET and Contractor, and should be based on the mitigation measures for the air pollution control as recommended in Appendix A.  In the event that the recommended mitigation measures are not fully or properly implemented, the Contractor should report the deficiency to the Engineer and ET.  The appropriate action will need to be taken by the Contractor:

(i)            Investigate the problems and causes;

(ii)           Discuss a remedial and corrective proposal with the ER and ET;

(iii)         Take action according to the action notes agreed with the ER;

(iv)         Implement the remedial and corrective action immediately;

(v)          Re-inspect the site conditions upon the completion of the remedial and corrective action; and

(vi)         Record the event.