4.0               AIR QUALITY MONITORING

 

4.1        Monitoring Requirement

 

TSP levels were monitored in the reporting month in accordance with the EM&A Manual. Table 4.5 shows the Action and Limit Levels for the environmental monitoring works.

 

4.2        Monitoring Equipment

 

Both 1-hour and 24-hour TSP air quality monitoring was performed using a GMWS2310 High Volume Air Sampler (HVS) located at each of the designated monitoring station. Table 4.1 summarizes the equipment used in the air quality monitoring programme. A copy of the calibration certificates for the HVS and portable dust meter are attached in Appendix B1.

 

Table 4.1           Air Quality Monitoring Equipment

Equipment

Model and Make

HVS

Greasby GMWS2310

Calibrator

Tisch TE-5025A

Wind Data Logger

Davis Weather Monitor II

 

4.3        Monitoring Parameters, Frequency and Duration

 

Table 4.2 summarizes the monitoring parameters, monitoring duration and frequencies of air quality monitoring.

 

            Table 4.2           Monitoring parameters, duration, frequency of air quality monitoring

Parameter

Duration

Frequency

24-hr TSP

24 hr

Once every six days

1-hr TSP

1 hr

Three times per day every six days

 

4.4        Monitoring Locations and Schedule

 

            Table 4.3 tabulates the air quality monitoring locations of this project.

 

Table 4.3           Air quality monitoring locations

Monitoring station

Location

AA1

Outside CEDD Site Office

AA2

Site Egress

 

During the reporting month, 1-hr and 24-hr TSP monitoring were carried out as the schedule. The details for 24-hr and 1-hr TSP monitoring carried out in this reporting month are summarized in table 4.4.


 

            Table 4.4           Monitoring Schedule for the air quality monitoring stations

Air quality monitoring stations

Location

Monitoring Period

 

24-hr TSP

1-hr TSP

 

Start

Finish

Date

Start

Finish

 

Date

Time

Date

Time

 

AA1

Outside CEDD Site Office

---

02/03/06

11:00

12:00

13:00

14:00

15:00

16:00

08/03/06

08:30

09:30

 

09:40

10:40

 

11:00

12:00

 

14/03/06

11:00

12:00

 

15:30

16:30

 

16:40

17:40

 

20/03/06

11:00

12:00

 

13:15

14:15

 

14:30

15:30

 

24/03/06

11:00

12:00

 

13:00

14:00

 

14:02

15:02

 

30/03/06

09:45

10:45

 

11:00

12:00

 

13:00

14:00

 

AA2

Site Egress

---

02/03/06

11:00

12:00

 

13:00

14:00

 

15:00

16:00

 

08/03/06

08:30

09:30

 

09:40

10:40

 

11:00

12:00

 

14/03/06

11:00

12:00

 

15:30

16:30

 

16:40

17:40

 

20/03/06

11:00

12:00

 

13:15

14:15

 

14:30

15:30

 

24/03/06

11:00

12:00

 

13:05

14:05

 

14:07

15:07

 

30/03/06

09:45

10:45

 

11:00

12:00

 

13:00

14:00

 

AA1

Outside CEDD Site Office

02/03/06

16:15

03/03/06

16:55

---

 

08/03/06

12:15

09/03/06

12:24

 

14/03/06

17:50

15/03/06

17:42

 

20/03/06

16:00

21/03/06

16:07

 

24/03/06

15:04

25/03/06

15:01

 

30/03/06

14:15

31/03/06

14:49

 

AA2

Site Egress

02/03/06

16:15

03/03/06

16:56

---

 

08/03/06

12:15

09/03/06

12:22

 

14/03/06

17:50

15/03/06

18:00

 

20/03/06

16:00

21/03/06

16:50

 

24/03/06

15:09

25/03/06

15:11

 

30/03/06

14:15

31/03/06

14:16

 

 

 

4.5        Monitoring Methodology

 

Both 1-hr and 24-hr air quality monitoring (High Volume Sampler)

 

Instrumentation

High volume sampler, as HVS, (Greasby GMWS2310) complete with appropriate sampling inlets were employed for both 1-hour and 24-hour TSP monitoring. The sampler is composed of a motor, a filter holder, a flow controller and a sampling inlet and its performance specification complies with that required by USEPA standard Title 40, Code of Federation Regulations Chapter 1 (Part 50).

 

Installation

The installation of HVS refers to the requirement stated in EM&A Manual.

 

Operation/Analytical Procedures

Operating/analytical procedures for the operation of HVS are as below:

 

Prior to the commencement of the dust sampling, the flow rate of the high volume sampler was properly set (between 0.6m3/min and 1.7m3/min.) in accordance with the manufacturer’s instruction to within the range recommended in USEPA Standard Title 40, CFR Part 50.

·          For TSP sampling, fiberglass filters (GA-55) were used.

·          The power supply was checked to ensure the sampler worked properly.

·          On sampling, the sampler was operated 5 minutes to establish thermal equilibrium before placing any filter media at designated air monitoring station.

·          The filter holding frame was then removed by loosening the four nuts and carefully a weighted and conditioned filter was centered with the stamped number upwards, on a supporting screen.

·          The filter was aligned on the screen so that the gasket formed an air-tight seal on the outer edges of the filter.  Then the filter holder frame was tightened to the filter holder with swing bolts. The applied pressure should be sufficient to avoid air leakage at the edges.

·         The programmable timer will be set for a sampling period of 24 hours.  Information was recorded on the record sheet, which included the starting time, the weather condition and the filter number (the initial weight of the filter paper can be found out by using the filter number.).

·         After sampling, the filter was transferred from the filter holder of the HVS to a sealed plastic bag and sent to the laboratory for weighting.  The elapsed time was also recoded.

·         Before weighting, all filters were equilibrated in a desiccator for 24 hour with the temperature of 25oC + 3oC and the relative humidity (RH) <50% +5%.

·         All measurement procedures in Section 2.3 of the EM&A Manual were followed during the reporting month.

 

Maintenance & Calibration

 

·          The HVS and their accessories should be maintained in good working condition, such as replacing motor brushes routinely and checking electrical wiring to ensure a continuous power supply.

·          HVS should be calibrated at bi-monthly intervals.

 

            Wind Data Monitoring

 

Measuring Procedure

 

Upon installation of the wind data logger on site, temperature, wind speed and direction was automatically stored in the logger. Regular downloading of the information was carried out weekly.

 

Maintenance

 

Cleaning was provided for all the rotational parts of the wind data logger regularly. Replacement of battery was carried out weekly. The wind data logger was checked once per week and no calibration was required for the equipment as instructed by the manufacturer.

 

4.6        Action and Limit Levels

 

Table 4.5 shows the Action and Limit levels for 24-hr TSP and 1-hr TSP monitoring.

 

Table 4.5           Action and Limit Levels for 24-hr TSP and 1-hr TSP

Monitoring Location

24-hr TSP (mg/m3)

1-hr TSP (mg/m3)

Action Level *

Limit Level *

Action Level *

Limit Level *

AA1

210

260

376

500

AA2

210

260

376

500

* Traceable to Method Statement (Environmental Monitoring and Audit Manual) of Contract No.CV/2002/08, Rev. 2

 

 

4.7        Event-Action Plans

 

Please refer to Appendix F for details. 

 

4.8        Results and Observation

 

4.8.1     1-hour and 24-hour TSP Monitoring results

 

All monitoring data of both 1-hour and 24-hour TSP monitoring is provided in Appendix B2. Graphical presentation of 1-hour and 24-hour TSP monitoring results for the reporting month is shown in Appendix B3. Wind data, including wind speed and wind direction, are annexed in Appendix E. Table 4.6 summarizes 1-hr TSP and 24-hr TSP monitoring results.

 

Table 4.6         Summary of 1-hr TSP and 24-hr TSP Monitoring Results

Air quality monitoring Stations

Location

Monitoring Period

24-hr TSP

1-hr TSP

Date

Result (mg/m3)

Exceedance #

Date

Start Time

Result (mg/m3)

Exceedance #

AA1

Outside CEDD Site Office

02/03/06

202

X

02/03/06

11:00

345

X

13:00

336

15:00

309

08/03/06

175

X

08/03/06

08:30

315

X

09:40

332

11:00

359

14/03/06

171

X

14/03/06

11:00

362

X

15:30

322

16:40

308

20/03/06

192

X

20/03/06

11:00

370

X

13:15

352

14:30

344

24/03/06

192

X

24/03/06

11:00

358

X

13:00

347

14:02

335

30/03/06

202

X

30/03/06

09:45

325

X

11:00

374

13:00

362

A2

Site Egress

02/03/06

194

X

02/03/06

11:00

330

X

13:00

318

15:00

285

08/03/06

168

X

08/03/06

08:30

282

X

09:40

314

11:00

352

14/03/06

162

X

14/03/06

11:00

371

X

15:30

351

16:40

314

20/03/06

188

X

20/03/06

11:00

366

X

13:15

360

14:30

328

24/03/06

191

X

24/03/06

11:00

354

X

13:05

343

14:07

320

30/03/06

195

X

30/03/06

09:45

336

X

11:00

368

13:00

357

Remark (#): L=Limit Level exceedance, A=Action Level exceedance and X= not an exceedance

 

No exceedances of Action and Limit Level of both 1-hour and 24-hour TSP monitoring results were recorded during the reporting month.

 

4.8.2     Observation

 

Generally, the Contractor implemented sufficient dust mitigation measures, including operation of the mist spraying systems at the CEDD Combined Reception Office and the site egress area, wheel washing facilities, road dampening by water bowsers and automatic water sprinklers on the main haul roads. Furthermore, hydroseeded slopes on the stockpiling areas was maintained properly in order to prevent dust generation from wind erosion of the exposed surfaces. Besides the Fill Bank operation, the other dust sources near TKO Area 137 also included operation of the C&DMSF at PBR2 Project, the temporary C&DMSF at Portion K and dumping activities at the SENT Landfill.