2.                  AIR QUALITY

2.1                Monitoring Requirement

2.1.1                In accordance with the EM&A Manual, 1-hour Total Suspended Particulates (TSP) levels should be measured at the designated air quality monitoring stations to ensure that any deteriorating air quality could be readily detected and timely action shall be undertaken to rectify such situation. Impact 1-hour TSP monitoring was conducted for at least three times every 6 days when the highest dust impact occurs.

2.2                Monitoring Equipment

2.2.1                A portable direct reading dust meter was used to carry out the 1-hour TSP monitoring at the designated monitoring stations.

2.2.2                Wind data monitoring equipment is provided at the conspicuous locations for logging wind speed and wind direction near to the dust monitoring locations. The equipment installation location is agreed with the ER and the IEC.

2.2.3                The details of the air quality monitoring equipment used are summarized in Table 3.

2.3                Monitoring Methodology for Direct Reading Dust Meter

2.3.1                SIBATA LD-5R Digital Dust Indicator complete with appropriate sampling inlets are employed for 1-hour TSP measurement.

Measuring Procedures

a) Pulling up the air sampling inlet cover

b) Changing the Mode 0 to BG

c) Pressing Start/Stop switch

d) Turning the knob to SENSI.ADJ and press it

e) Pressing Start/Stop switch again

f) Returning the knob to the position MEASURE slowly

g) Pressing the timer set switch to set measuring time

h) Removing the cap and start the measurement

Equipment Calibration

1-hour dust meter should be calibrated at 1 year intervals. The calibration certificates are presented in Appendix D.

2.4                Maintenance and Calibration for Direct Reading Dust Meter

2.4.1                ET shall submit sufficient information to the IEC to prove that the instrument is capable of achieving comparable results 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. The calibration certificate for the direct reading dust meter is provided in Appendix D.

2.5                Monitoring Locations

2.5.1                In accordance with the EM&A Manual, two air quality monitoring locations, namely AM1, AM2 are covered under Contract No. SPW 02/2023 “Environmental Team for Construction of Yuen Long Effluent Polishing Plant Stage 1”.

2.5.2                The most updated locations are summarized in Table 4 and the locations of the air monitoring stations shown in Figure 2.

2.6                Monitoring Results

2.6.1                The schedule of air quality monitoring in reporting month is provided in Appendix E.

2.6.2                No Action / Limit Level exceedance was recorded for 1-hr TSP at AM1 and AM2.

2.6.3                No effect that arose from the other special phenomena and work progress of the concerned site was noted during the current monitoring month.

2.6.4                The weather and meteorological conditions during the monitoring are provided in Appendix K.

2.6.5                The Air Quality Monitoring Results of 1-hr TSP are summarized in Table 5. Detailed monitoring data are presented in Appendix F.

2.6.6                The Action and Limit Levels for air quality monitoring have been set and are presented in Appendix C.

2.6.7                The Event and Action Plan for air quality is given in Appendix H.

2.6.8                The wind data obtained from the on-site wind station during the reporting period is provided

in Appendix G.

2.7                Comparison of 1-hr TSP Monitoring Results with EIA Predictions

2.7.1                The monitoring data of 1-hr TSP was compared with the EIA predictions as summarized in Table 6.

2.7.2                The 1-hr TSP monitoring results at AM1 and AM2 were below the Predicted Maximum Hourly Average TSP Concentration in the approved Environmental Impact Assessment (EIA) Report.