2.            AIR QUAILITY MONITORING

2.1         Monitoring Locations

2.1.1     The air quality monitoring works for the Contract are covered by Contract No. HY/2013/01 “Hong Kong-Zhuhai-Macao-Bridge HKBCF – Passenger Clearance Building” and Contract No. HY/2011/03 “Hong Kong-Zhuhai-Macao Bridge Hong Kong Link Road – Section between Scenic Hill and HKBCF”. The ET of the Contract or another ET of the HZMB project is required to conduct impact air quality monitoring at AMS6 and AMS7 as part of EM&A programme if these air quality monitoring stations are no longer covered under Contract No. HY/2013/01 and HY/2011/03. Figure 1 shows the locations of air monitoring stations.

Table 2.1 Air Quality Monitoring Location

Air Monitoring Station

Location

AMS6

Dragonair/CNAC (Group) Building (A80)

AMS7

Hong Kong SkyCity Marriott Hotel

2.2         Monitoring Requirements

2.2.1     The monitoring requirements, equipment, parameters, frequency and duration, methodology, schedule, and meteorological information are described in the monthly EM&A Reports prepared for Contract No. HY/2013/01 and HY/2011/03.

2.2.2     The Action and Limit levels for 1-hr TSP and 24-hr TSP are summarized in Table 2.2.

Table 2.2 Action and Limit Levels for Air Quality

Monitoring Station

Action Level (µg/m³)

Limit Level (µg/m³)

1 hour TSP

AMS6

360

500

AMS7

370

24 hours TSP

AMS6

173

260

AMS7

183

 

2.2.3     The event and action plan is provided in Appendix D.

2.2.4     If exceedance(s) at these stations is/are recorded by the ET of the Contract or referred by the other ET under the HZMB project to the Contract, the ET of the Contract will carry out an investigation and findings will be reported in the monthly EM&A Report.

2.3         Monitoring Results

2.3.1     The monitoring results for AMS6 and AMS7 are reported in the monthly EM&A Reports prepared for Contract No. HY/2011/03 and HY/2013/01 respectively.

2.3.2     Summary of Action and Limit Level exceedance of 1-hr TSP level and 24-hr TSP level at AMS6 shall be referred to the monthly EM&A report prepared by Contract No. HY/2011/03.

2.3.3     There was no Action and Limit Level exceedances of 1-hr TSP level and 24-hr TSP level recorded at station AMS7 by the Environmental Team of Contract No. HY/2013/01 during the reporting period.

2.3.4     There was one Action and Limit Level exceedances of 24-hr TSP level recorded at station AMS3B by the Environmental Team of Contract No. HY/2013/01 during the reporting period.

2.3.5     Regarding the exceedance on 23 December 2017, the mitigation measures according to Water Spraying Arrangement in November 2017 (Appendix B) are implemented to avoid dust emission. The Contractor has provided the guideline to remind the site vehicles travel within speed limit of 8km/hr. For 24-hr TSP exceedance recorded at the station AMS3B, information available on EPD’s Air Quality Health Index (AQHI) website shows that the hourly AQHI of Tung Chung station ranged 3 to 8 (Low to Very High) on 23 and 24 December 2017 during monitoring period. The AQHI data is available online at http://www.aqhi.gov.hk/epd/ddata/html/history/2017/201712_ChS.csv. According to the wind data at on-site wind station, no prevailing wind direction was found in the monitoring period. The Vehicle Clearance Plazas and Ancillary Buildings and Facilities site of HKBCF is far away from AMS3B (more than 1km). No potential dust source was observed near the monitoring station at AMS3B during the monitoring period. It was unlikely that the works undertaken by Contract No. HY/2013/03 caused 24-hr TSP exceedance recorded at the station AMS3B on 23 December 2017.