TABLE OF CONTENTS
2.4 Monitoring Parameters,
Frequency and Duration
3.4 Monitoring Parameters,
Frequency and Duration
List of Tables
Table 2.1 Air Quality Monitoring
Equipment
Table 2.2 Locations of Baseline Air
Monitoring Stations
Table 2.3 Air Quality Monitoring
Parameters, Frequency and Duration
Table 2.4 Summary of 1-hour TSP
Baseline Monitoring Results
Table 2.5 Summary of 24-hour TSP
Baseline Monitoring Results
Table 2.6 Derivation of Action and
Limit Levels for Air Quality
Table 2.7 Action and Limit Levels
for Air Quality
Table 3.1 Noise Monitoring
Equipment
Table 3.2 Locations of Baseline
Noise Monitoring Station
Table 3.3 Noise Monitoring
Parameters, Frequency and Duration
Table 3.4 Summary of Baseline Noise
Monitoring Results
Table 3.7 Criteria for Action and Limit Levels for Construction
Noise
Table 3.8 Action and Limit Levels for Construction Noise of the
Project
Figures
Figure 2.1 Locations
of Air Quality Monitoring Stations During Baseline Monitoring
Figure 3.1 Location
of Noise Monitoring Stations During Baseline Monitoring
List of Appendix
Appendix A Calibration Certificates of Monitoring Equipments
Appendix B Baseline Air Quality Monitoring Results
Appendix C Baseline Noise Monitoring Results
EXECUTIVE SUMMARY
The
proposed construction of interconnection tunnel and diaphragm wall for main
pumping station at Stonecutters Island Sewage Treatment Works (SCISTW) (the
Project) is a Designated Project under the Environmental Impact Assessment
Ordinance (Cap. 499) (EIAO) and is governed by an
Environmental Permit (EP-322/2008/B). The Project comprises the construction of
Interconnection Tunnel between the Inlet Chamber of the Main Pumping Station
and the existing Riser Shaft and diaphragm wall for the Main Pumping Station
In accordance with the Environmental
Monitoring and Audit Manual (EM&A Manual) of the Project, baseline
monitoring of air quality and noise is required prior to commencement of
construction of the Project. As accesses to some of
the proposed monitoring stations as stipulated in the EM&A manual have been
rejected by other parties or found to be not available or not suitable, a
Monitoring Proposal, presenting the alternative monitoring stations,
requirements and methodologies for the monitoring, was submitted.
This
report documents the baseline monitoring of air quality at 1 monitoring station
and noise monitoring at 1 monitoring station as described in the Monitoring
Proposal. For monitoring station at Block A of Government Dockyard mentioned in
the Monitoring Proposal, as monitoring station will be established by the
Contract DE/2009/02 (Provision of Covers and Deodourisation Facilities to the
Existing Sedimentation Tanks at SCISTW), so baseline monitoring details at this
station are not mentioned in this report.
The
baseline monitoring of both air quality and noise was carried out between 23
November 2009 and 6 December 2009. Air quality was recorded in terms of 1-hour
Total Suspended Particulates (TSP) and 24-hour TSP. The weather during the
monitoring period was mainly sunny. For baseline noise levels, Leq(30-minute)
were recorded for non-restricted Restricted Hours (07:00 – 19:00 on normal weekdays) and Leq(5-minute)
were recorded for restricted Restricted Hours (19:00 – 23:00 and 23:00 – 07:00 of next day
on normal weekdays, whole day on General Holidays and Sundays).
The averaged 1-hour TSP levels and 24-hour TSP levels at AM7 are summarized as follows:
|
Air quality monitoring
location |
AM7 |
|
Averaged 1-hr TSP (μg/m3) |
110 |
|
Averaged 24-hr TSP (μg/m3) |
119 |
The averaged baseline
noise levels are summarized in the following table:
|
Noise monitoring location |
NM6 |
|
Averaged baseline noise level during daytime on normal weekdays (Leq(30
min), dB(A)) |
76.5 |
|
Averaged baseline noise level during evening on normal weekdays (Leq(5 min),
dB(A)) |
60.4 |
|
Averaged baseline noise level during daytime and evening on General Holidays and Sundays (Leq(5 min),
dB(A)) |
61.5 |
|
Averaged baseline noise level during night-time on all days (Leq(5 min),
dB(A)) |
59.6 |
1
introduction
1.1.1.
China State - Shanghai Tunnel Joint Venture was
awarded the Contract No. DC/2009/05 Harbour Area Treatment Scheme (HATS) Stage
1.1.2.
The Project is a designated project and is governed
by an Environmental Permit (EP-322/2008/B).
1.1.3.
The scope of the Project comprises mainly:
|
n |
l Construction of Interconnection
Tunnel with concrete lining between the Inlet Chamber of the Main Pumping
Station and the existing Riser Shaft; l Construction of diaphragm wall, base
slab and pile cap for the Main Pumping Station and its Inlet Chamber; l Excavation within the diaphragm walls
for the Main Pumping Station and its
Inlet Chamber to founding levels; l Piling works for the Main Pumping
Stations; l Utilities upgrading and diversion
works; l Temporary launching shaft to be
handed over to MPS Contractor; l Carrying out ground monitoring and
instrumentation works; l Carrying out pumping test; l Miscellaneous building, civil and
electrical and mechanical works; and l Landscape works. |
1.1.4.
In accordance with the EM&A Manual of the
Project, environmental baseline conditions were established by the ET prior to
the commencement of construction of the Project.
1.1.5.
As accesses to some of
the proposed monitoring stations as stipulated in the EM&A manual have been
rejected by other parties or found to be not available or not suitable, a
Monitoring Proposal, presenting the alternative monitoring stations,
requirements and methodologies for the monitoring, was submitted.
1.1.6.
Baseline
monitoring was undertaken and baseline monitoring report was prepared prior to
commencement of construction of the Project.
1.2.
Purpose of the
Baseline Monitoring Report
1.2.1.
The purpose of this report is to review the
baseline conditions of the Project site and to establish baseline levels for
air and noise in accordance with the EM&A Manual and Monitoring Proposal.
These levels would be used as the basis for assessing environmental impact and
compliance during construction of the Project.
1.2.2.
This baseline monitoring
report presents the baseline monitoring requirements, methodologies and
monitoring results of air quality and noise conducted at 1 air quality
monitoring station and 1 noise monitoring station described in the Monitoring
Proposal.
2
Air quality monitoring
2.1 Monitoring Requirements
2.1.1
In accordance with the EM&A Manual and the Monitoring Proposal, baseline 1-hour
and 24-hour TSP levels at 2 air quality
monitoring stations should be established by conducting baseline 1-hour and 24-hour
TSP monitoring for at least 14 days.
2.2 Monitoring Equipment
2.2.1
24-hour TSP air quality monitoring was performed using High
Volume Sampler (HVS) located at designated monitoring station. The HVS meets
all the requirements of the EM&A Manual. Portable direct reading dust meter was
used to carry out the 1-hour TSP monitoring at designated monitoring
station. Brand and model of the
equipment is given in Table
2.1.
Table
2.1 Air
Quality Monitoring Equipment
|
Equipment |
Brand and
Model |
|
Portable direct reading dust meter |
Sibata Digital Dust Monitor (Model No.
LD-3 & LD-3B) |
|
High Volume Sampler |
Graseby Andersen Total Suspended
Particulate Mass Flow Controlled Sampling System (Model No. GMWS2310) |
2.3 Monitoring Locations
2.3.1
Monitoring
location at Block A of Government Dockyard stated in the Monitoring Proposal,
which monitoring station had been set up at the proposed location by the other
contract (HATS Stage 2A – Provision of Advanced Disinfection Facilities (ADF)
at SCISTW) in the Year 2008, will be established by the Contract DE/2009/02
(Provision of Covers and Deodourisation Facilities to the Existing
Sedimentation Tanks at SCISTW). Therefore, no baseline monitoring details at this
station are mentioned in this report.
2.3.2
Monitoring location AM7 was set up at
the proposed location in accordance with the
Monitoring Proposal and as agreed by the ER and the IEC. Figure 2.1 shows the location
of monitoring station. Table
2.2
describes the details of the monitoring stations.
Table 2.2 Locations
of Baseline Air Monitoring Stations
|
Monitoring Station |
Location |
Description |
|
AM7 |
West Kowloon No. 2 Sewage Pumping Station |
Rooftop of the premise |
2.4 Monitoring Parameters, Frequency and Duration
2.4.1
Table
2.3 summarizes
the monitoring parameters, frequency and duration of baseline TSP monitoring.
Table 2.3 Air
Quality Monitoring Parameters, Frequency and Duration
|
Parameter |
Frequency and
Duration |
|
1-hour TSP |
3
times (at three consecutive Restricted Hours) per day while the highest dust impact was
expected, for 14 days |
|
24-hour TSP |
Daily,
for 14 days |
2.5 Monitoring Methodology
2.5.1
24-Hr TSP Monitoring
(a)
The HVS was installed in the vicinity of the air
sensitive receivers. The following
criteria were considered in the installation of the HVS.
(i)
A
horizontal platform with appropriate support to secure the sampler against
gusty wind to be provided.
(ii)
The
distance between the HVS and any obstacles, such as buildings, was at least twice
the height that the obstacle protrudes above the HVS.
(iii)
A
minimum of 2 meters separation from walls, parapets and penthouse for rooftop
sampler.
(iv)
A
minimum of 2 meters separation from any supporting structure, measured
horizontally is required;
(v)
No
furnace or incinerator flues nearby.
(vi)
Airflow
around the sampler to be unrestricted.
(vii)
Permission
to be obtained to set up the samplers and access to the monitoring stations.
(viii)
A
secured supply of electricity to be obtained to operate the samplers.
(ix)
The
sampler should be located more than 20 meters from any dripline.
(x)
Any
wire fence and gate, required to protect the sampler, should not obstruct the
monitoring process.
(xi)
Flow control accuracy was kept within ±2.5%
deviation over 24-hour sampling period.
(b)
Preparation of Filter Papers
(i)
Glass fibre filters, G810 were labelled and
sufficient filters that were clean and without pinholes were selected.
(ii)
All filters were equilibrated in the conditioning
environment for 24 Restricted Hours before weighing. The conditioning environment
temperature was around
(iii)
All filter papers were prepared and analysed by ALS
Technichem (HK) Pty Ltd., which is a HOKLAS accredited laboratory and has
comprehensive quality assurance and quality control programmes.
(c)
Field Monitoring
(i)
The power supply was checked to ensure the HVS
works properly.
(ii)
The filter holder and the area surrounding the
filter were cleaned.
(iii)
The filter holder was removed by loosening the four
bolts and a new filter, with stamped number upward, on a supporting screen was
aligned carefully.
(iv)
The filter was properly aligned on the screen so
that the gasket formed an airtight seal on the outer edges of the filter.
(v)
The swing bolts were fastened to hold the filter
holder down to the frame. The
pressure applied was sufficient to avoid air leakage at the edges.
(vi)
Then the shelter lid was closed and was secured
with the aluminum strip.
(vii)
The HVS was warmed-up for about 5 minutes to
establish run-temperature conditions.
(viii)
A new flow rate record sheet was set into the flow
recorder.
(ix)
On site temperature and atmospheric pressure
readings were taken and the flow rate of the HVS was checked and adjusted at around
1.1 m3/min, and complied with the range specified in the updated
EM&A Manual (i.e. 0.6-1.7 m3/min).
(x)
The programmable digital timer was set for a
sampling period of 24 hrs, and the starting time, weather condition and the
filter number were recorded.
(xi)
The initial elapsed time was recorded.
(xii)
At the end of sampling, on site temperature and
atmospheric pressure readings were taken and the final flow rate of the HVS was
checked and recorded.
(xiii)
The final elapsed time was recorded.
(xiv)
The sampled filter was removed carefully and folded
in half length so that only surfaces with collected particulate matter were in
contact.
(xv)
It was then placed in a clean plastic envelope and
sealed.
(xvi)
All monitoring information was recorded on a
standard data sheet.
(xvii)
Filters were then sent to ALS Technichem (HK) Pty
Ltd. for analysis.
(d)
Maintenance and Calibration
(i)
The HVS and its accessories were maintained in good
working condition, such as replacing motor brushes routinely and checking
electrical wiring to ensure a continuous power supply.
(ii)
HVSs were calibrated using TE
(iii)
Calibration certificate of the TE
2.5.2
1-hour TSP Monitoring
(a)
Measuring Procedures
The measuring procedures of the 1-hour dust
meter were in accordance with the Manufacturer’s Instruction Manual as follows:
(i)
Turn the power on.
(ii)
Close the air collecting opening cover.
(iii)
Push the “TIME SETTING” switch to [BG]
(iv)
Push “START/STOP” switch to perform background
measurement for 6 seconds.
(v)
Turn the knob at SENSI ADJ position to insert the
light scattering plate.
(vi)
Leave the equipment for 1 minute upon “SPAN CHECK”
is indicated in the display.
(vii)
Push “START/STOP” switch to perform automatic
sensitivity adjustment. This measurement takes 1 minute.
(viii)
Pull out the knob and return it to MEASURE
position.
(ix)
Push the “TIME SETTING” switch the time set in the
display to 3 Restricted Hours.
(x)
Lower down the air collection opening cover.
(xi)
Push “START/STOP” switch to start measurement.
(b)
Maintenance and Calibration
(i)
The 1-hour TSP meter was calibrated at 1-year
intervals against a continuous particulate TEOM Monitor, Series 1400ab. Calibration certificates of the Laser
Dust Monitors are provided in Appendix A.
2.6 Results and Observations
2.6.1
The baseline monitoring at the Monitoring Station AM7 was carried out
between 23 November 2009 and 6 December 2009, during which, the weather was
mostly sunny. Although construction works
from other contract, about 280m away from the
Monitoring Station AM7, were
being carried out during some days in the monitoring period (from 1 Dec 2009 to
5 Dec 2009), the construction works was considered not contributing to major dust emissions as
the construction works during the abovementioned 5 days included only diaphragm wall construction
by hydromill method and removal of excavated materials including marine deposit
generated from the diaphragm wall construction.
2.6.2
Baseline 1-hour TSP and 24-hour TSP monitoring for the Monitoring
Station AM7 was carried out from 23 November 2009 to 6 December 2009 for
consecutively 14 days.
2.6.3
The baseline monitoring results for 1-hour TSP and 24-hour
TSP are summarized in Table
2.4
and 2.5 respectively.
Detailed air quality monitoring results for
Monitoring Station AM7 are presented in Appendix
B.
Table
2.4 Summary
of 1-hour TSP Baseline Monitoring Results
|
|
AM7 |
|
Average (μg/m3) |
110 |
|
Range (μg/m3) |
73 - 225 |
Table
2.5 Summary
of 24-hour TSP Baseline Monitoring Results
|
|
AM7 |
|
Average (μg/m3) |
119 |
|
Range (μg/m3) |
66 - 190 |
2.7 Action and Limit Levels
2.7.1
The air quality monitoring results, in terms of 1-hour TSP
and 24-hour TSP were below the Limit Level set out in the Air Quality Objective
(AQO) at both monitoring locations.
2.7.2
The Action and Limit Levels for air quality impact
monitoring were based on the criteria adopted from the EM&A Manual as
presented in Table 2.6.
Table 2.6 Derivation
of Action and Limit Levels for Air Quality
|
Parameter |
Action Level |
Limit Level |
|
1-hour TSP Level in μg/m3 |
For Baseline Level <384 μg/m3, Action Level = (130% of baseline level + Limit level) ÷ 2 For Baseline Level > 384 μg/m3, Action Level = Limit Level |
500 |
|
24-hour TSP
Level in μg/m3 |
For Baseline Level <200 μg/m3, Action Level = (130% of baseline level + Limit level) ÷ 2 For Baseline Level > 200 μg/m3, Action Level = Limit Level
|
260 |
2.7.3
Table
2.7
shows the derived Action and Limit Levels for air quality impact monitoring for
the Project.
Table 2.7 Action
and Limit Levels for Air Quality
|
Parameter |
Monitoring Station |
Action Level (μg/m3) |
Limit Level (μg/m3) |
|
1-hour TSP
Level in μg/m3 |
AM7 |
322 |
500 |
|
24-hour TSP Level in μg/m3 |
AM7 |
207 |
260 |
3
Noise MONITORING
3.1 Monitoring Requirements
3.1.1
In accordance with the EM&A Manual and the Monitoring Proposal, baseline noise
levels at 1 monitoring station
should be established by conducting daily noise monitoring for 2 weeks.
3.2 Monitoring Equipment
3.2.1
Noise monitoring was performed using sound level meter at
each designated monitoring station.
The sound level meters deployed comply with the International
Electrotechnical Commission Publications (IEC) 651:1979 (Type 1) and 804:1985
(Type 1) specifications. Acoustic
calibrator was deployed to check the sound level meters at a known sound
pressure level. Brand and model of
the equipment is given in Table
3.1.
Table 3.1 Noise
Monitoring Equipment
|
Equipment |
Brand and Model |
|
Integrated Sound Level
Meter |
B&K (Model No.
2238, 2250L and 2270) |
|
Acoustic Calibrator |
B&K (Model No.
4231) |
3.3 Monitoring Locations
3.3.1
Monitoring station NM6 was set up at the proposed locations in
accordance with the
Monitoring Proposal. Figure
3.1 shows the location
of the monitoring station. Table
3.2 describes
the details of the monitoring station.
Table 3.2 Locations
of Baseline Noise Monitoring Station
|
Monitoring Station |
Location |
Description |
|
NM6 |
Customs’ Marine
Base |
1m from the exterior of the roof façade of Block H of Government
Dockyard |
3.4 Monitoring Parameters, Frequency and Duration
3.4.1
Table
3.3
summarizes the monitoring parameters, frequency and duration of baseline noise
monitoring.
Table 3.3 Noise
Monitoring Parameters, Frequency and Duration
|
Time Period |
Duration, min |
Parameters |
|
Daytime: 0700-1900
hrs on normal weekdays |
30 (Leq(30-min)) |
Leq, L90
& L10 |
|
Evening: 1900-2300
hrs on normal weekdays |
15 (3 consecutive Leq(5-min)) |
|
|
General
Holidays and Sundays: 0700-2300
hrs |
||
|
Night-time: 2300-0700
hrs of next day on all days |
3.5 Monitoring Methodology
3.5.1
Monitoring Procedure
(a)
Façade measurements (i.e. 1m from the exterior of
the building façade) were made at all monitoring locations.
(b)
The battery condition was checked to ensure the
correct functioning of the meter.
(c)
Parameters such as frequency weighting, the time
weighting and the measurement time were set as follows:
(i)
frequency weighting: A
(ii)
time weighting: Fast
(iii)
time measurement: Leq(30-minutes) during
non-restricted Restricted Hours i.e. 07:00 – 1900 on normal weekdays; Leq(5-minutes) x3
during restricted Restricted Hours i.e. 19:00
– 23:00 and 23:00 – 07:00 of normal weekdays, whole day of Sundays and Public
Holidays
(d)
Prior to and after each noise measurement, the
meter was calibrated using the acoustic calibrator for 94dB(A) at 1000 Hz. If the difference in the calibration
level before and after measurement was more than 1 dB(A), the measurement would
be considered invalid and repeat of noise measurement would be required after
re-calibration or repair of the equipment.
(e)
During the monitoring period, the Leq, L10
and L90 were recorded.
In addition, site conditions and noise sources were recorded on a
standard record sheet.
(f)
Noise measurement was paused during periods of high
intrusive noise (e.g. dog barking, helicopter noise) if possible. Observations
were recorded when intrusive noise was unavoidable.
(g)
Noise monitoring was cancelled in the presence of
fog, rain, wind with a steady speed exceeding
3.5.2
Maintenance and Calibration
(a)
The microphone head of the sound level meter was
cleaned with soft cloth at regular intervals.
(b)
The meter and calibrator were sent to the supplier
or HOKLAS laboratory to check and calibrate at yearly intervals.
(c)
Calibration certificates of the sound level meters
and acoustic calibrators are provided in Appendix
A.
3.6 Results and Observations
3.6.1
There was no other major activity influencing the measured
noise level during the baseline noise monitoring period. The dominant noise
sources were from community noises and nearby cargos.
3.6.2
Baseline noise monitoring was conducted for consecutively 2 weeks, from 23 November
2009 to 6 December 2009.
3.6.3
The baseline noise monitoring results are summarized in Tables 3.4 to 3.6. Detailed noise monitoring results
are presented in Appendix
C.
Table 3.4 Summary
of Baseline Noise Monitoring Results
|
Time period |
30-min Mean
of Noise Levels for time period (1) / 5-min Mean of Noise Levels for time period (2, (3) & (4), dB(A) |
Range, dB(A) |
||
|
Leq |
L10 |
L90 |
Leq |
|
|
(1) 0700-1900
hrs on normal weekdays |
76.5 |
77.5 |
75.0 |
70.8 – 78.9 |
|
(2) 1900-2300
hrs on normal weekdays |
60.4 |
62.1 |
58.3 |
58.4 – 63.8 |
|
(3) 0700-2300 hrs on General Holidays and Sundays |
61.5 |
64.1 |
58.7 |
58.6 – 64.4 |
|
(4) 2300-0700
hrs of next day on
all days |
59.6 |
60.5 |
58.2 |
58.0 – 61.0 |
3.6.4
Although
no construction work was carried out in the vicinity during the course of
measurement, the averaged baseline daytime noise levels recorded at the monitoring location exceeded the Limit Level of 75dB(A).
3.6.5
The averaged baseline night-time noise monitoring results
exceeded the criteria of 55dB(A) at the monitoring
location.
3.7 Action and Limit Levels
3.7.1
The Action and Limit Levels of noise monitoring have been
set in accordance with the derivation criteria specified in the EM&A Manual
as shown in Table 3.7 below.
Table 3.7 Criteria for
Action and Limit Levels for Construction Noise
|
Time
Period |
Action
Level |
Limit
Levels |
|
0700-1900 hrs of normal weekdays |
When one documented complaint is received |
75 dB(A)* |
Notes: If works are
to be carried out during restricted Restricted Hours, the conditions stipulated in the Construction
Noise Permit (CNP) issued by the Noise Control Authority have to be followed.
* 70 dB(A) and 65 dB(A)
for schools during normal teaching periods and school examination periods,
respectively.
3.7.2
The
Project area is within non-designated area under the Noise Control Ordinance
(NCO) while Area Sensitivity Ratings of the noise sensitive receivers (NSRs) of the
Projects are considered as “C” as they are directly affected industrial areas. With
considering the monitoring location NM6 is not a NSR and it serves as the only
accessible alternative monitoring location for the planned monitoring location
at Planned FSD Diving Rescue and Diving Training Centre (named as M11 in the
EM&A Manual), the Limit Level as stipulated in the EM&A Manual is adopted. The Action and
Limit Levels for impact noise monitoring are derived and presented in Table 3.8 below.
Table 3.8 Action and
Limit Levels for Construction Noise of the Project
|
Time
Period |
Monitoring
Station |
Action
Level |
Limit
Levels |
|
0700-1900 hrs on normal weekdays |
NM6 |
When one documented complaint is received |
75 dB(A) |
|
1900-2300 hrs on normal weekdays, 0700-2300 hrs on
General Holidays and Sundays |
NM6 |
When one documented complaint is received |
70 dB(A) |
|
2300-0700 hrs of
next day on all days |
NM6 |
When one documented complaint is received |
55 dB(A) |