3                    ENVIRONMENTAL MONITORING REQUIREMENTS

3.1              Air Quality

Monitoring Requirements

3.1.1        In accordance with the approved EM&A Manual 1-hour and 24-hour Total Suspended Particulates (TSP) are required to be conducted to monitor the construction dust impact.  The established Action/Limit Levels for the environmental monitoring works are presented in Appendix D1.

Monitoring Frequency and Schedule

3.1.2        The monitoring parameters and frequency are summarized in Table 3.1.  The monitoring schedule for the reporting period is presented in Appendix E.

Table 3.1 TSP Monitoring Parameter and Frequency

Parameters

Duration / hour

Frequency

24-hour TSP

24

Once Every Six Days

1-hour TSP

1

Three Times Every Six Days

 

Monitoring Locations

3.1.3        For Phase 1 Contract, a total of five air sensitive receivers were identified according to the EM&A Manual.  The air quality monitoring stations, namely ASR1 and ASR2, had already commenced since the commencement of the construction of the Phase 1 Contract.  For ASR3 (Site 10, Hoi Lai Estate), the construction works of Hoi Lai Estate were substantially completed by end of November 2004 and occupied by residents on 10th December 2004. Therefore, the air quality monitoring was carried out at ASR3 since 17th December 2004.  Two other potential sensitive receivers were also identified at Site 6 and CDA Site, but no baseline monitoring was carried out as these sites were still unoccupied by residents.

3.1.4        The three monitoring stations (ASR1, ASR2 and ASR3) are listed in Table 3.2 and are presented in Appendix F.

Table 3.2 TSP Monitoring Locations

Location I.D.

Description

ASR1

Lai Chi Kok Park

Mei Foo Sun Chuen (at the roof of the toilet block)

ASR2

DSD Pumping Station

(in the proximity of Stonecutters Military Base)

ASR3

Hoi Lai Estate

Hoi Yin House  (roof, 40/F )

 

3.1.5        Wind data monitoring was carried out at the area P1-SA9 for logging wind speed and wind direction.

Monitoring Equipment

3.1.6        Continuous 24-hour and 1-hour TSP air quality monitoring was performed using a TE-5170 Tisch Environmental Inc. High Volume Air Sampler (HVS), which was installed at the ASR1, ASR2 and ASR3. The sampler composed of a motor, filter holder, flow controller and a sampling inlet.  Its performance specification complies with that required by USEPA Standard Title 40, Code of Federation Regulations Chapter 1 (Part 50).

3.1.7        Details of the monitoring equipment are given in Table 3.3.  A copy of the calibration certificate for the HVS and wind data monitor are attached in Appendix G1 and Appendix G2 respectively.

Table 3.3 Air Quality Monitoring Equipment

Equipment

Model

Qty.

HVS

TE-5170 Tisch Environmental Inc.

3

Calibrator

TE-5028A Tisch Environmental Inc.

1

 

Monitoring Procedures and Calibration Details of HVS

3.1.8        Calibration Procedures - Calibration procedures of HVS are as follows (calibration certificates are presented in Appendix G1) :

i.           A certified orifice transfer standard with a calibration curve was used for the calibration.

ii.          The transfer standard was connected to the inlet of the sampler.  The orifice manometer was then connected to the orifice pressure port.  The manometer’s connecting tubing was inspected to make sure that there are no leaks between the orifice unit and the sampler.

iii.        The motor was then disconnected from the flow controller and plugged directly to an AC power source.

iv.        A weather station has been setup at the Site Office to measure and record the ambient temperature, Ta (K) and the barometer pressure Pa (mmHg) during calculation.

v.         The sampler was allowed to run for at least 2 minutes to re-establish the run temperature conditions.  The pressure drop across the orifice and the well-type manometer reading was recorded during calibration.  The variable resistance was adjusted to repeat recording for four different flow rates.

vi.        The best fit straight line was determined by linear regression and the slope (m1), intercept (b1) and correlation coefficient (r) are then determined.

 

3.1.9        Operating/Analytical Procedure

i.           The flow rate of the HVS was set to about 1.1m3/min-1.7m3/min prior to commencement of the dust sampling in accordance with the manufacturer's instruction to within the range recommended in USEPA Standard Title 40, CFR Part 50.

ii.          The samplers was located such that:

the filter was about 1.3 meters above ground.

it was greater than 20 meters away from trees.

it was separated from any obstacle by at least twice the height of the obstacle protruding above the sampler.

it has unrestricted airflow 270° around the sampler.

iii.        Fiberglass filters were used for TSP sampling (G810) [Note: these filters have a collection efficiency of > 99% for particles of 0.3 mm diameter.

iv.        All filters were equilibrated in the conditioning environment for 24 hours before weighing. The conditioning environment has a temperature setting between 25°C and 30°C and should not vary by more than ±3°C; the relative humidity was < 50% and should not vary by more than ±5%.

v.         A new filter was placed with stamped number upward on a supporting screen.

vi.        The filter was properly aligned on the screen so that the gasket formed an air-tight seal on the outer edges of the filter.

vii.      Shelter lid closed and catch secured with the aluminum strip.

viii.     The sampler was then allowed to run for at least 5 minutes to establish run-temperature conditions.

ix.        The flow indicator reading was recorded and the sampler flow rate was determined.

x.         The programmable timer was set and the starting sampling time, weather condition and the filter number was recorded.

xi.        At the end of sampling, the filter was transferred from the filter holder of the HVS to a sealable plastic bag and sent to the HOKLAS accredited laboratory for weighing.  The elapsed time was also recorded. A copy of the HOKLAS Certificate is attached in Appendix G5.

xii.      Before weighing, all filters were equilibrated in a desiccator for 24 hours with temperature of 25°C±3°C and the relative humidity (RH) 50%±5%, preferably 40%.

 

3.1.10    Maintenance

i.           The high volume sampler and their accessories were maintained in good working condition; include replacing motor brushes routinely and checking electrical wiring to ensure continuous power supply.

ii.          The high volume samplers were calibrated at bi-monthly intervals using TE-5028A Tisch Environmental Inc. Calibration Kit throughout all stages of the air quality monitoring.

 

Event/Action Plan

3.1.11    The Event/Action Plan for Air Quality is presented in Appendix H1.

 

3.2              Noise Quality

Monitoring Requirements

3.2.1        Noise monitoring was conducted at three monitoring stations to monitor the construction noise impact. 

3.2.2        According to the field study, the noise generated from the major roads (such as Route 3 highway and Container Port Road) was noticeable at all noise monitoring stations and therefore the major roads were considered as an influencing factor of the noise sensitive receivers. 

3.2.3        As the noise monitoring stations are located at urban area and directly affected by this Influencing Factor (IF), the Area Sensitivity Rating of the noise monitoring stations is considered to be “C” according to the Table 1 of the Technical Memorandum on Noise from Construction Work other than Percussive Piling under Noise Pollution Control Ordinance.

3.2.4        The Action/Limit Levels for the environmental monitoring works is established according to the EM&A manual and the Technical Memorandum under Noise Pollution Control Ordinance and is presented in Appendix D2.

Monitoring Frequency and Schedule

3.2.5        The monitoring schedule is presented in Appendix E and the frequency and parameters of noise measurement are summarized in Table 3.4. 

Table 3.4 Noise Monitoring Frequency and Parameters

Time Period

Duration / min.

Parameters

Frequency

  Daytime (0700 to 1900)

30  (6 consecutive Leq(5min) in average)

Leq, L90 & L10

Once per week

*Evening (1900 to 2300)

5

Leq, L90 & L10

Six times per week

*Night (2300 to 0700 next day)

5

Leq, L90 & L10

Four times per week

*Holiday (0700-1900 on holidays)

5

Leq, L90 & L10

Six times per week

     * Restricted hour noise monitoring: to be conducted only when there is construction work carried out under valid CNP.

 

Monitoring Locations

3.2.6        For Phase 1 Contract, a total of five noise sensitive receivers were identified according to the EM&A Manual.  The noise monitoring stations, namely NSR1 and NSR2, had already commenced since the commencement of the construction of the Phase 1 Contract.  For NSR3, the noise monitoring was carried out since 17th December 2004.  Two other potential sensitive receivers were also identified at Site 6 and CDA site, but no baseline monitoring was carried out at these sites as they were not occupied by residents.

3.2.7        The three monitoring stations (NSR1, NSR2 and NSR3) are detailed in Table 3.5 and presented in Appendix F.

Table 3.5 Location of the Noise Monitoring Stations

Location I.D.

Description

Type of measurement

NSR1

Lai Chi Kok Park

Mei Foo Sun Chuen (at the roof of the toilet block)

Free Field

NSR2

DSD Pumping Station

(in the proximity of Stonecutters Military Base)

Free Field

NSR3

Hoi Lai Estate

Hoi Yin House (roof, 40/F)

Free Field

 

Monitoring Equipment

3.2.8        Integrating Sound Level Meters were used for noise monitoring which were Type 1 sound level meters capable of giving a continuous readout of the noise level readings including equivalent continuous sound pressure level (Leq) and percentile sound pressure level (Lx).  They comply with International Electrotechnical Commission Publications 651:1979 (Type 1) and 804:1985 (Type 1). Also, a portable electronic wind speed indicator capable of measuring wind speed in m/s was used to monitor the wind speed. Table 3.6 summarizes the noise monitoring equipment required.

Table 3.6 Noise Monitoring Equipment

Equipment

Model

Integrating Sound Level Meter

SC-30, CESVA

NL-31, Rion

Calibrator

CB-5, CESVA

Portable Wind Speed Indicator

PWM2, Dwyer

Monitoring Procedures and Calibration Details

3.2.9        Field Monitoring

i.           The microphone of the Sound Level Meter (with weatherproof kit) was mounted on a tripod at a height of 2m above ground level.

ii.          For free field measurement, the meter was positioned away from any nearby reflective surfaces.

iii.        AC power supply was checked to ensure good functioning of the meter.

iv.        Parameters such as frequency weighting, the time weighting and the measurement time were set as follows:

frequency weighting           :           A

time weighting        :           Fast

time measurement  :           30 minutes / 5 minutes

v.         Prior to and after each noise measurement, the meter was calibrated using the Calibrator for 94 dB at 1000 Hz.  If the difference in the calibration level before and after measurement was more than 1 dB, the measurement would be considered invalid and repeat of noise measurement would be required after re-calibration or repair of the equipment.

vi.        The wind speed was frequently checked with the portable wind meter.

vii.      At the end of the monitoring period, the Leq, L90 and L10 were recorded.  In addition, site conditions and noise sources were recorded on a standard record sheet.

viii.     Noise measurement was paused during periods of high intrusive noise if possible and observation was recorded when intrusive noise was not avoided.

ix.        Noise monitoring was cancelled in the presence of fog, rain, and wind with steady speed exceeding 5 m/s, or wind with gusts exceeding 10m/s.

 

3.2.10    Maintenance and Calibration

i.           The microphone head of the sound level meter and calibrator were cleaned with a soft cloth at quarterly intervals.

ii.          The meter was sent to the supplier to check and calibrate yearly.

iii.        Calibration certificates are presented in Appendix G4.

 

Event/Action Plan

3.2.11    The Event/Action Plan for Noise impact is presented in Appendix H2.