2                     Air Quality

Introduction

2.1               This section presents the requirements, methodology, equipment, monitoring locations, criteria and protocols for the monitoring and audit of air quality impact during the construction and operation phase of the Project.

 

2.2               The objectives of the air quality monitoring include the following:

 

·         to identify the extent of construction dust impact on sensitive receivers;

·         to determine the effectiveness of mitigation measures in controlling fugitive dust emission from activities during the construction phase;

·         to audit the compliance of the Contractor with regard to dust control, contract conditions and the relevant dust impact criteria;

·         to recommend further mitigation measures if found to be necessary; and

·         to comply with Action and Limit (A/L) Levels for air quality as defined in this Manual.

2.3               During construction phase of the Project, dust impacts would be the major air quality impacts.  While during operation phase of the Project, stack emissions would be the key environmental issue.

Air Quality Parameters

Construction Phase

 

2.4               The ambient air quality criteria to be monitored and assessed are:

 

·         The Hong Kong Air Quality Objectives (AQOs) for Total Suspended Particulates (TSP), 24-hour TSP levels of 260mgm-3; and

·         1-hour TSP limit of 500 mgm-3

2.5               These levels are not to be exceeded at Air Sensitive Receivers (ASRs).  Monitoring of the TSP levels shall be conducted by the ET to detect any deteriorating air quality and to take timely action to rectify such situation.

 

Operation Phase

 

2.6               During operation of the new crematorium, the air pollutants of concern include nitrogen oxides, sulphur dioxide, respirable suspended particulate, total organic carbon, hydrogen chloride, carbon monoxide, mercury and dioxins.  The predicted air quality at the nearby ASRs would comply with the AQOs and relevant air quality guidelines with the implementation of recommended mitigation measures.  No odour nuisance from the new crematorium is anticipated.  By incorporating flue gas treatment system in joss paper burners and limiting joss paper burning activities through administration procedures, nuisance arising from joss paper burning is anticipated to be negligible.

 

2.7               In order to ensure compliance with the legislation requirements, the conditions and the continuous monitoring stipulated in the BPM12/2(06) – A Guidance Note on the Best Practicable Means for Incinerators (Crematoria), published by EPD, shall be conducted.   The monitoring of the air pollutants shall comply with the requirements of BPM and future Specified Process License of new crematorium, to be issued by EPD under the APCO. 

Monitoring during Construction Phase

Monitoring Equipment

2.8               High volume samples (HVSs) in compliance with the following specifications shall be used for carrying out the 1-hour and 24-hour TSP monitoring:

·    0.6 - 1.7 m3 per minute adjustable flow range;

·         equipped with a timing / control device with +/- 5 minutes accuracy for 24 hours operation;

·         installed with elapsed-time meter with +/- 2 minutes accuracy for 24 hours operation;

·         capable of providing a minimum exposed area of 406 cm2;

·         flow control accuracy: +/- 2.5% deviation over 24-hour sampling period;

·         equipped with a shelter to protect the filter and sampler;

·         incorporated with an electronic mass flow rate controller or other equivalent devices;

·         equipped with a flow recorder for continuous monitoring;

·         provided with a peaked roof inlet;

·         incorporated with a manometer;

·         able to hold and seal the filter paper to the sampler housing at horizontal position;

·         easily changeable filter; and

·    capable of operating continuously for a 24-hour period.

2.9               The ET is responsible for provision of the monitoring equipment.  They shall ensure that sufficient number of HVSs with an appropriate calibration kit are available for carrying out the baseline monitoring, regular impact monitoring and ad hoc monitoring.  The HVSs shall be equipped with an electronic mass flow controller and be calibrated against a traceable standard at regular intervals.  All the equipment, calibration kit, filter papers, etc., shall be clearly labeled.

 

2.10            Initial calibration of dust monitoring equipment shall be controlled upon installation and thereafter at bi-monthly intervals.  The transfer standard shall be traceable to the internationally recognized primary standard and be calibrated annually.  The concern parties such as IEC shall properly document the calibration data for future reference.  All the data should be converted into standard temperature and pressure condition.

 

2.11            The flow-rate of the sampler before and after the sampling exercise with the filter in position shall be verified to be constant and be recorded in the data sheet as mentioned in Appendix B.

 

2.12            If the ET proposes to use a direct reading dust meter to measure 1-hour TSP levels, he shall submit sufficient information to the IEC to prove that the instrument is capable of achieving a comparable result to the HVS.  The instrument should also be calibrated regularly, and the 1-hour sampling shall be determined periodically by the HVS to check the validity and accuracy of the results measured by direct reading method.

 

2.13            Wind data monitoring equipment shall also be provided and set up for logging wind speed and wind direction near the dust monitoring locations.  The equipment installation location shall be proposed by the ET and agreed with the IEC.  For installation and operation of wind data monitoring equipment, the following points shall be observed:

·   The wind sensors should be installed 10 m above ground so that they are clear of obstructions or turbulence caused by buildings.

·         The wind data should be captured by a data logger.  The data shall be downloaded for analysis at least once a month.

·         The wind data monitoring equipment should be re-calibrated at least once every six months.

·    Wind direction should be divided into 16 sectors of 22.5 degrees each.

2.14            In exceptional situations, the ET may propose alternative methods to obtain representative wind data upon approval from the ER and agreement from the IEC.

Laboratory Measurement / Analysis

2.15            A clean laboratory with constant temperature and humidity control, and equipped with necessary measuring and conditioning instruments to handle the dust samples collected, shall be available for sample analysis, and equipment calibration and maintenance.  The laboratory should be HOKLAS accredited.

 

2.16            If a site laboratory is set up or a non-HOKLAS accredited laboratory is hired for carrying out the laboratory analysis, the laboratory equipment shall be approved by the ER and the measurement procedures shall be witnessed by the IEC.  Any measurement performed by the laboratory shall be demonstrated to the satisfaction of the ER and IEC.  IEC shall regularly audit to the measurement performed by the laboratory to ensure the accuracy of measurement results.  The ET Leader shall provide the ER with one copy of the Title 40 of the Code of Federal Regulations, Chapter 1 (Part 50), Appendix B for his reference.

 

2.17            Filter paper of size 8" x 10" shall be labelled before sampling.  It shall be a clean filter paper with no pinholes, and shall be conditioned in a humidity-controlled chamber for over 24-hours and be pre-weighed before use for the sampling.

 

2.18            After sampling, the filter paper loaded with dust shall be kept in a clean and tightly sealed plastic bag.  The filter paper shall then be returned to the laboratory for reconditioning in the humidity-controlled chamber followed by accurate weighing by an electronic balance with readout down to 0.1 mg.  The balance shall be regularly calibrated against a traceable standard.

 

2.19            All the collected samples shall be kept in a good condition for 6 months before disposal.

Monitoring Locations

2.20            The dust monitoring stations for construction phase are shown in Figure 2.1.

Baseline Monitoring

2.21            Baseline monitoring shall be carried out at all of the designated monitoring locations for at least 14 consecutive days prior to the commissioning of the construction works to obtain daily 24-hour TSP samples.  The selected baseline monitoring stations should reflect baseline conditions at the impact stations.  One-hour sampling should also be done at least 3 times per day while the highest dust impact is expected.

 

2.22            During the baseline monitoring, there should not be any construction or dust generation activities in the vicinity of the monitoring stations.  Before commencing baseline monitoring, the ET shall inform the IEC of the baseline monitoring programme such that the ER can conduct on-site audit to ensure accuracy of the baseline monitoring results.

 

2.23            In case the baseline monitoring cannot be carried out at the designated monitoring locations during the baseline monitoring period, the ET Leader shall carry out the monitoring at alternative locations that can effectively represent the baseline conditions at the impact monitoring locations.  The alternative baseline monitoring locations shall be approved by the ER and agreed with the IEC.

 

2.24            In exceptional cases, when insufficient baseline monitoring data or questionable results are obtained, the ET shall liaise with the IEC and EPD to agree on an appropriate set of data to be used as a baseline reference and submit to ER for approval.

 

2.25            Ambient conditions may vary seasonally and shall be reviewed once every three months.  When the ambient conditions have changed and a repeat of the baseline monitoring is required to be carried out for obtaining the updated baseline levels, the monitoring should be at times when the Contractor's activities are not generating dust, at least in the proximity of the monitoring stations.  Should change in ambient conditions be determined, the baseline levels and, in turn, the air quality criteria, should be revised.  The revised baseline levels and air quality criteria should be agreed with the IEC and EPD.

Impact Monitoring

2.26            The ET shall carry out impact monitoring during the course of the Works.  For regular impact monitoring, the sampling frequency of at least once in every six-days, shall be strictly observed at all the monitoring stations for 24-hour TSP monitoring.  For 1-hour TSP monitoring, the sampling frequency of at least three times in every six-days should be undertaken when the highest dust impact occurs.  Before commencing baseline monitoring, the ET shall inform the IEC of the impact monitoring programme such that the IEC can conduct on-site audit to ensure accuracy of the impact monitoring results.

 

2.27            The specific time to start and stop the 24-hour TSP monitoring shall be clearly defined for each location and be strictly followed by the operator.

 

2.28            In case of non-compliance with the air quality criteria, more frequent monitoring, as specified in the Action Plan in the following section, shall be conducted within 24 hours after the result is obtained.  This additional monitoring shall be continued until the excessive dust emission or the deterioration in air quality is rectified.

Environmental Quality Performance Limits

2.29            The baseline monitoring results form the basis for determining the air quality criteria for the impact monitoring.  The ET shall compare the impact monitoring results with air quality criteria set up for 24-hour TSP and 1-hour TSP.  Table 2.1 shows the air quality criteria, namely Action and Limit levels to be used.

 

Table 2.1      Action / Limit Levels for Air Quality

Parameters

Action

Limit

24-hour TSP Level in gm-3

For baseline level £ 200 gm-3,

Action level = (baseline level * 1.3 + Limit level)/2;

For baseline level > 200 gm-3 Action level = Limit level

260 gm-3

1-hour TSP Level in gm-3

For baseline level £ 384 gm-3,

Action level = (baseline level * 1.3 + Limit level)/2;

For baseline level > 384 gm-3 Action level = Limit level

500 gm-3

Event and Action Plan

2.30            Should non-compliance of the air quality criteria occur, actions in accordance with the Action Plan in Table 2.2 shall be carried out.

Mitigation Measures

2.31            As described in the EIA Report, all ASRs would comply with AQO and EIAO-TM criteria during construction phase of the Project.  Mitigation measures for dust control have been recommended in the EIA Report and are listed below:

·    skip hoist for material transport should be totally enclosed by impervious sheeting;

·         every vehicle should be washed to remove any dusty materials from its body and wheels before leaving a construction site;

·         the area where vehicle washing takes place and the section of the road between the washing facilities and the exit point should be paved with concrete, bituminous materials or hardcores;

·         where a site boundary adjoins a road, streets or other accessible to the public, hoarding of not less than 2.4m high from ground level should be provided along the entire length except for a site entrance or exit;

·         every stack of more than 20 bags of cement should be covered entirely by impervious sheeting places in an area sheltered on the top and the 3 sides;

·         all dusty materials should be sprayed with water prior to any loading, unloading or transfer operation so as to maintain the dusty materials wet;

·         the excavation area should be limited to as small in size as possible and backfilled with clean and/or treated soil shortly after excavation work;

·         the height from which excavated materials are dropped should be controlled to a minimum practical height to limit fugitive dust generation from unloading;

·         the load of dusty materials carried by vehicle leaving a construction site should be covered entirely by clean impervious sheeting to ensure dust materials do not leak from the vehicle; and


Table 2.2          Event / Action Plan for Construction Air Quality

EVENT

ACTION

ET

IEC

ER

CONTRACTOR

ACTION LEVEL

1.     Exceedance for one sample

1.     Identify source, investigate the causes of exceedance and propose remedial measures;

2.     Inform IEC and ER;

3.     Repeat measurement to confirm finding;

4.     Increase monitoring frequency to daily.

(The above actions should be taken within 2 working days after the exceedance is identified)

1.   Check monitoring data submitted by ET;

2.   Check Contractor’s working method.

(The above actions should be taken within 2 working days after the exceedance is identified)

1.                            Notify Contractor;

(The above actions should be taken within 2 working days after the exceedance is identified)

1.Rectify any unacceptable practice;

2.Amend working methods if appropriate.

(The above actions should be taken within 2 working days after the exceedance is identified)

2.     Exceedance for two or more consecutive samples

1.     Identify source;

2.     Inform 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 IEC and Contractor on remedial actions required;

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

8.     If exceedance stops, cease additional monitoring.

(The above actions should be taken within 2 working days after the exceedance is identified)

1.   Check monitoring data submitted by ET;

2.   Check Contractor’s working method;

3.   Discuss with ET and Contractor on possible remedial measures;

4.   Advise the ET on the effectiveness of the proposed remedial measures;

5.   Supervise implementation of remedial measures.

(The above actions should be taken within 2 working days after the exceedance is identified)

1.  Confirm receipt of notification of failure in writing;

2.  Notify Contractor;

3.  Ensure remedial measures properly implemented.

(The above actions should be taken within 2 working days after the exceedance is identified)

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

2.Implement the agreed proposals;

3.Amend proposal if appropriate.

(The above actions should be taken within 2 working days after the exceedance is identified)

LIMITED LEVEL

1.     Exceedance for one sample

1.     Identify source, investigate the causes of exceedance and propose remedial measures;

2.     Inform ER, Contractor and EPD;

3.     Repeat measurement to confirm finding;

4.     Increase monitoring frequency to daily;

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

(The above actions should be taken within 2 working days after the exceedance is identified)

1.   Check monitoring data submitted by ET;

2.   Check Contractor’s working method;

3.   Discuss with ET and Contractor on possible remedial measures;

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

5.   Supervise implementation of remedial measures.

(The above actions should be taken within 2 working days after the exceedance is identified)

1.  Confirm receipt of notification of failure in writing;

2.  Notify Contractor;

3.  Ensure remedial measures properly implemented.

(The above actions should be taken within 2 working days after the exceedance is identified)

1.Take immediate action to avoid further exceedance;

2.Submit proposals for remedial actions to IEC within 3 working days of notification;

3.Implement the agreed proposals;

4.Amend proposal if appropriate.

(The above actions should be taken within 2 working days after the exceedance is identified)

2.     Exceedance for two or more consecutive samples

1.     Notify IEC, ER, Contractor and EPD;

2.     Identify source;

3.     Repeat measurement to confirm findings;

4.     Increase monitoring frequency to daily;

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

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

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

8.     If exceedance stops, cease additional monitoring.

(The above actions should be taken within 2 working days after the exceedance is identified)

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

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

3.   Supervise the implementation of remedial measures.

1.  Confirm receipt of notification of failure in writing;

2.  Notify Contractor;

3.  In consolidation with the IEC, agree with the Contractor on the remedial measures to be implemented;

4.  Ensure remedial measures properly implemented;

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

(The above actions should be taken within 2 working days after the exceedance is identified)

1.Take immediate action to avoid further exceedance;

2.Submit proposals for remedial actions to IEC within 3 working days of notification;

3.Implement the agreed proposals;

4.Resubmit proposals if problem still not under control;

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

(The above actions should be taken within 2 working days after the exceedance is identified)

·         instigation of an environmental monitoring and auditing program to monitor the construction process in order to enforce controls and modify method of works if dusty conditions arise.

 

2.32            The implementation schedule for recommended air quality mitigation measures is presented in Appendix A.

Monitoring during Operation Phase

Stack Monitoring

 

2.33            Monitoring of air quality parameters of concern due to stack emissions has to be conducted during operation phase of the Project in accordance with the requirements stipulated in the “A Guidance Note on the Best Practicable Means for Incinerators (Crematoria) BPM12/2(06)” and the future Specified Process License of new crematorium, to be issued by EPD under APCO.

 

2.34            It should be noted that the proposed sampling methods below are for reference only and should be subject to the approval of EPD.

 

2.35            Necessary monitoring equipment and techniques should be provided and used to demonstrate that the process is properly operated and the emissions can be minimized to meet the air pollution control requirements.  The scope, manner and frequency of the monitoring should be sufficient for this purpose and will be determined by EPD.  Monitoring results should be recorded in such manner specified by EPD.  The record should be retained at the premises for a minimum of two years, or other period specified by EPD, after the date of last entry and be made available for examination as and when required by EPD.

 

2.36            On-line monitoring, process continuous monitoring and periodic measurement shall be carried out and the results shall be properly recorded.  Evidence should be provided to demonstrate quality assurance procedures are in place to ensure all monitoring results are sufficiently accurate and reliable.  Calibration on the monitoring equipment has to be done by means of parallel measurements with the reference methods as agreed by EPD.  The requirements of the on-line monitoring and periodic measurement are provided in the following sections:

 

On-line & Process Continuous Monitoring

 

2.37            Continuous monitoring of the in-stack exhaust gas and the process shall be carried out. The air pollutants and parameters to be continuously monitored shall comply with the requirements of the BPM 12/2(06) and the future Specified Process License of new crematorium, to be issued by EPD under APCO. The continuous monitoring data should be transmitted instantaneously to EPD by telemetry system or the real time and logged monitoring data shall be accessible by EPD in such manner and format agreed with EPD.

Periodic Measurement

 

2.38            To confirm that the levels of air pollutants being adequately controlled, periodic measurements shall be made. The air pollutants and parameters to be periodically monitored and the sampling frequency shall comply with the requirements of the BPM12/2(06) and the future Specified Process License of new crematorium, to be issued by EPD under APCO.

 

2.39            All measurement results shall be recorded, processed and presented in a summary report as agreed by EPD.  The report shall be submitted to EPD without delay after the source sampling(s) as required is/are completed.