1.1.1
Civil Engineering
and Development Department (hereafter referred as “CEDD”) is the Project
Proponent and the Permit Holder of Agreement No. CE 59/2005 (EP)
Development of a Bathing Beach at Lung Mei, Tai Po (hereinafter
referred as “the Project”), which is a Designated Project to be implemented
under Environmental Permit number EP-388/2010 (hereinafter
referred as “the EP-388/2010” or “the EP”).
1.1.2
The major construction activities of the
Project comprise construction 200-metre long bathing beach with a groyne at each end, a shark
prevention net; a public car park; retaining walls; and the associated
roadworks, drainage and sewerage works. Layout plan of the Project is shown in Appendix A.
1.1.3
Furthermore, the project works is under Environmental Permit
(EP) No. EP-388/2010 as a Designated Project and the designated works
include:
(i)
Construction of a 200m long beach with a groyne at each end of the beach which includes dredging and
sandfilling works;
(ii)
Construction of one culvert at the eastern side of the
beach and another small section of culvert and open drainage channel with gabion
embankments at the western end, both to collect and divert surface runoff from
upstream locations; and
(iii)
Construction of a beach building with associated beach
building facilities, kiosk and a carpark and associated road improvement works
adjoining the facility.
1.1.4
Action-United
Environmental Services & Consulting (hereinafter
referred as “AUES”) has been commissioned as an Independent Environmental Team
(hereinafter referred as “the ET”) to implement the relevant EM&A
program in accordance with the approved
EM&A Manual, as well as the associated duties. As part of the EM&A program,
baseline monitoring is required to determine the ambient environmental
conditions. Therefore, baseline
monitoring of air quality was undertaken on 7 June 2017 to 20 June 2017 and for
noise was carried out on 7
June 2017 to 23 June 2017 before construction work commencement. With regard to the
baseline water quality monitoring, it will be carried out prior to the
commencement of dredging and sandfilling activities and the relevant baseline monitoring report will be provided stand-alone.
1.1.5
During the baseline monitoring period for air
quality and noise, there were no construction activities of this project or
other external influencing factors of significant concern observed by the ET.
1.1.6
This Baseline Monitoring Report presents the
details of the baseline study including project background, monitoring
methodology, monitoring results, summary of findings, and Action/Limit (A/L)
Levels established for subsequent use in the Project construction phase
EM&A program.
1.2.1
The Baseline Monitoring Report is structured
into the following sections:-
Section 1 Introduction
Section 2 Summaries of Baseline
Monitoring Requirement.
Section 3 Baseline Monitoring Methodology
Section 4 Baseline Monitoring
Results
Section 5 Conclusion and
Recommendation
2.1.1
The Environmental Monitoring and Audit requirements are set out in
the EM&A manual. Environmental issues such as air quality and construction
noise were identified as the key issues during the construction phase of the
Project. A summary of the baseline
EM&A requirements for air and noise monitoring are presented in the sub-sections
below.
2.1.2
According to the EM&A Manual, baseline monitoring shall only
cover air quality.
However, in order to obtain the baseline noise condition before
commencement of the Project, as agreed by the Contractor, baseline noise monitoring shall
be included
in baseline monitoring programme.
2.2.1
A summary of the monitoring parameters is presented in Table
2-1 below.
Table 2-1 Summary
of EM&A Requirements
|
Environmental Issue
|
Parameters
|
|
Air
Quality
|
Ÿ 1-hour TSP
Ÿ 24-hour TSP
|
|
Noise
(#)
|
Ÿ
Leq (30min) in six consecutive Leq(5 min) between 07:00-19:00 on normal
weekdays
Ÿ
3 sets of consecutive Leq (5min) on
restricted hours i.e. public holiday or Sunday
Ÿ
Statistical result such as L10 and
L90 for supplementary information
|
Remark (#) Since there are
no requirements for baseline noise monitoring in the EM&A Manual, the
monitoring parameters are based on the general practice of the EM&A
programme.
Air Quality
2.3.1
Two designated air quality monitoring locations are recommended in Section
3.1 of the
EM&A Manual and they are listed in Table 2-2 below and
illustrated in Appendix
B.
Table 2-2 Designated
Air Quality Monitoring Station according to the
EM&A Manual
|
ASR
|
Location
|
|
A4
|
No. 101 Lung Mei Tsuen
|
|
A6
|
No. 79 Lo Tsz
Tin Tsuen
|
2.3.2
During liaison with the landlord of A6,
he refused to provide access and location for installation of HVAS. Therefore, alternative location (A7) was proposed by
ET in accordance with Section 3.4 of the EM&A Manual. The proposed alternative locations are considered capable
of effectively representing the baseline conditions at the impact monitoring
locations. The proposal (ref no.: TCS00874/16/300/L0016b) for alternative monitoring
locations was verified IEC and it has been submitted to EPD for approval on 2 May 2017.
2.3.3
The baseline air quality monitoring locations are in Table 2-3 and
illustrated in Appendix
B.
Table 2-3 Summary of Baseline Air Quality Monitoring Stations
|
Station ID
|
Location
|
Justification
|
|
A4
|
No. 101 Lung Mei Tsuen
|
No
changes.
|
|
A7
|
Hong Kong Eco-Farm
|
It is one of the representative
ASR identified in the EIA which located at north-east of the site.
Granted with the area and power provision for HVS.
|
Construction
Noise
2.3.4
According to Section 4.1 of the
EM&A Manual, four
designated noise sensitive receivers (NSR) were
recommended and they are listed in Table 2-4 and illustrated in Appendix B.
Table 2-4 Designated
Noise Monitoring Station according to the EM&A Manual
|
NSR
|
Location
|
|
N1
|
Village
house - No. 165A Lung Mei
|
|
N2*
|
Village
house - No. 103 Lung Mei
|
|
N3
|
Village
house - No. 70 Lo Tsz Tin
|
|
N4
|
Village
house - No. 79 Lo Tsz Tin
|
Remarks:
(*) Noise monitoring should be conducted at N2a (i.e House No. 101 Lung Mei) if it is changed to residential
use during construction phase.
2.3.5
As confirmed on the first day of
baseline monitoring, N2a (House no. 101 Lung Mei) has been changed to
residential use. Therefore, the
baseline noise monitoring is conducted at N2a and to replace N2. Moreover, due to the lack of accessibility of noise
monitoring at NSR N3 (Village house – No. 70 Lo Tsz
Tin), alternative location was proposed to replace N3 to carry out
the baseline noise monitoring. Having reviewed the surrounding condition, NSR N3a (Village house – No. 66C Lo
Tsz Tin) was proposed with the rationales summarized in
below.
1)
The
distance between N3 and N3a is about 18 meter apart and N3a locates at close
proximity of the project site and major site activities which are likely to
have noise impacts;
2)
N3a is
a village type residential house and it is a noise sensitive receiver (NSR);
3)
Accessibility
for noise monitoring work at N3a is available; and
4)
Minimal
disturbance would be only caused to the proposed monitoring location N3a.
2.3.6
The proposed location N3a was accepted
by IEC and the
NSRs for the
baseline noise monitoring are listed in Table 2-5 and illustrated in Appendix B.
Table 2-5 Summary of Baseline Noise Monitoring Stations
|
Station ID
|
Description
|
|
N1
|
Village
house - No. 165A Lung Mei
|
|
N2a
|
Village
house - No. 101 Lung Mei
|
|
N3a
|
Village
house - No. 66C Lo Tsz Tin
|
|
N4
|
Village
house - No. 79 Lo Tsz Tin
|
2.4.1
The
baseline monitoring will be conducted immediately prior to commencement of the construction work under the
Project. No construction activities
are allowed to be undertaken during the baseline monitoring period.
Air Quality Monitoring
2.4.2
Monitoring frequency for air quality
baseline monitoring is as follows:
|
Frequency:
|
•
Daily for 24-hour TSP
•
Three times a day for 1-hour TSP while the highest dust impact is expected.
|
|
Duration:
|
14 consecutive
days
|
Noise Monitoring
|
Frequency:
|
•
Leq (30min) in 6
consecutive Leq(5min) between 07:00-19:00 on normal
weekdays
•
3 sets of consecutive Leq(5min)
on restricted hours i.e. public holiday or Sunday
•
L10 and
L90 for reference
|
|
Duration:
|
Two weeks
|
Air Quality Monitoring
2.5.1
The 24-hour and 1-hour TSP levels shall be measured by following
the standard high volume sampling method as set out in the Title 40 of the Code of Federal Regulations, Chapter 1 (Part 50), Appendix B. If the ET proposes to use a direct
reading dust meter to measure 1-hour TSP levels, it shall submit sufficient
information to the IEC to prove that the instrument is capable
of achieving a comparable results to the HVS. The instrument should be calibrated
regularly, and the 1-hour sampling shall be determined on yearly basis by the
HVS to check the validity and accuracy of the results measured by direct
reading method. The filter paper of 24-hour
TSP measurement shall be determined by HOKLAS accredited laboratory.
Noise Monitoring
2.5.2
Sound level meter in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1)
and 804: 1985 (Type 1) specifications shall be used for carrying out the noise
monitoring. The sound level meter shall
be checked using an acoustic calibrator.
The wind speed shall be checked with a portable wind speed meter capable
of measuring the wind speed in ms-1.
Wind
Data Monitoring Equipment
2.5.3
Meteorological information, including wind direction, wind speed, humidity,
rainfall, air pressure and temperature etc., which in general is required for
evaluating the air quality impact will be extracted from the Hong Kong
Observatory including Tai Po Station
(Air Temperature/Pressure and Relative Humidity) and Tai Mei Tuk Station (wind speed and
direction).
2.5.4
Two obvious advantages of using the HKO meteorological information
are:
(i)
Installation of a wind sensor of 10 metres
aboveground, according to the EM&A Manual, involves construction of the
foundation for the reasonably strong 10 meter metal pole, which, according to
the ET’s past experience, may provoke fierce opposition of the ASR owners, and
is therefore hardly to be practicable under limited time and resources; and
(ii)
HKO meteorological information is widely accepted to be used in
many environmental reports within HKSAR due to its professional quality and
precision, in addition to its readily availability and accessibility via the
HKO website.
2.6.1
The baseline results form the basis for determining the
environmental acceptance criteria for the impact monitoring. A summary of derivation of Action/Limit
(A/L) Levels for air quality and construction noise are shown in Table
2-6 and 2-7 respectively.
Table 2-6 Derivation
of Action and Limit Levels for Air Quality
|
Parameter
|
Action Level
|
Limit Level
|
|
24-hour
TSP
|
For
baseline level £ 200 mg/m3:
Action
level = (Baseline × 1.3 + Limit
level)/2
|
260
mg/m3
|
|
For
baseline level > 200 mg/m3:
Action
level = Limit level
|
|
1-hour
TSP
|
For
baseline level £ 384 mg/m3:
Action
level = (Baseline × 1.3 + Limit
level)/2
|
500
mg/m3
|
|
For
baseline level > 384 mg/m3:
Action
level = Limit level
|
Table 2-7 Derivation of Action
and Limit Levels for Construction Noise
|
Time Period
|
Action Level in dB(A)
|
Limit Level in dB(A)
|
|
0700-1900
hours on normal weekdays
|
When one documented complaint
is received
|
75*
dB(A)
|
Note: (*) Reduces
to 70 dB(A) for schools and 65 dB(A) during the school
examination periods.
2.6.2
Should
non-compliance of the environmental quality criteria occurs, remedial actions
will be triggered according to the Event and Action Plan which presented in Appendix D.
3.1.1
The baseline monitoring program of air quality was conducted on 7 June 2017 to 20 June 2017; and
noise was conducted from 7 June 2017 to 23 June 2017. During the baseline monitoring
period, there were no construction activities of this project or other external
influencing factors of significant concern observed by the ET.
3.2.1
Baseline air quality and noise monitoring have been undertaken at
the all monitoring stations from 7 June
2017 to 20 June 2017 and 7 June 2017 to 23 June 2017 respectively.
The detailed information of monitoring stations to be referred to Tables
2-4 and 2-5, and the
photographic record of the monitoring locations are shown in Appendix C.
3.3.1
All equipment to be used for baseline air quality monitoring is
listed in Table 3-1.
Table 3-1 Air
Quality Monitoring Equipment
|
Equipment
|
Model
|
|
24-Hour TSP
|
|
High Volume Air Sampler
|
TISCH High Volume Air Sampler, HVS Model
TE-5170
|
|
Calibration Kit
|
TISCH Calibration Kit Mode TE-5025A
|
|
1-Hour TSP
|
|
Portable Dust Meter
|
Sibata LD-3B Laser Dust Meter
|
3.3.2
Noise monitoring equipment to be used for baseline monitoring is
listed in Table 3-2.
Table 3-2 Construction
Noise Monitoring Equipment
|
Equipment
|
Model
|
|
Integrating Sound Level Meter
|
B&K
Type 2238 or Rion NL-31 or Rion
NL-52
|
|
Calibrator
|
B&K
Type 4231 or Rion NC-74
|
|
Portable Wind Speed Indicator
|
Anemometer
AZ Instrument 8908
|
3.4.1
The
procedures to conduct air quality and noise monitoring are summarized in
following sub-sections.
Air Quality
1-hour TSP
3.4.2
Operation of the 1-hour TSP meter will follow manufacturer’s Operation and Service Manual.
3.4.3
The 1-hour TSP monitor, brand named “Sibata LD-3B Laser Dust Meter” is a portable, battery-operated laser
photometer. The 1-hour TSP meter provides a real time 1-hour
TSP measurement based on 900 light scattering. The 1-hour TSP
monitor consists of the following:
a.
A pump
to draw sample aerosol through the optic chamber where TSP is measured;
b.
A
sheath air system to isolate the aerosol in the chamber to keep the optics
clean for maximum reliability; and
c.
A
built-in data logger compatible with Windows based program to facilitate data
collection, analysis and reporting.
3.4.4
The 1-hour
TSP meter to be used will be within the valid period, calibrated by the manufacturer
prior to purchasing. Zero response of the instrument will be checked before and after each monitoring event. Annually calibration with the High
Volume Sampler (HVS) in same condition would be undertaken by the Laboratory.
24-hour TSP
3.4.5
The equipment used for 24-hour TSP measurement is the High
Volume Sampler (hereinafter the “HVS”) brand named TISCH, Model TE-5170 TSP
High Volume Air Sampler, which complied with EPA Code of Federal Regulation, Appendix B to Part 50. The HVS consists of the following:
a.
An anodized aluminum shelter;
b.
A 8”x10” stainless steel filter holder;
c.
A blower motor assembly;
d.
A continuous flow/pressure recorder;
e.
A motor speed-voltage control/elapsed time indicator;
f.
A 7-day mechanical timer, and
g.
A power supply of 220v/50 hz
3.4.6
For HVS for 24-hour TSP monitoring, the HVS is mounted in a
metallic cage with a top for protection and also it is sat on the existing
ground or the roof of building. The
flow rate of the HVS between 0.6m3/min and 1.7m3/min will
be properly set in accordance with the manufacturer’s instruction to within the
range recommended in EPA Code of Federal
Regulation, Appendix B to Part 50. Glass Fiber Filter 8" x 10" of
TE-653 will be used for 24-Hour TSP monitoring and would be supplied by
laboratory. The general procedures
of sampling are described as below:-
Ÿ
A horizontal platform with appropriate support to secure the
samples against gusty wind should be provided;
Ÿ
No two samplers should be placed less than 2 meters apart;
Ÿ
The distance between the sampler and an obstacle, such as
building, must be at least twice the height that the obstacle protrudes above
the sample;
Ÿ
A minimum of 2 meters of separation from any supporting structure,
measured horizontally is required;
Ÿ
Before placing any filter media at the HVS, the power supply will
be checked to ensure the sampler work properly;
Ÿ
The filter paper will be set to align on the screen of HVS to
ensure that the gasket formed an air tight seal on the outer edges of the
filter. Then filter holder frame
will be tightened to the filter hold with swing bolts. The holding pressure should be
sufficient to avoid air leakage at the edge.
Ÿ
The mechanical timer will be set for a sampling period of 24 hours
(00:00 mid-night to 00:00 mid-night next day). Information will be recorded on the
field data sheet, which would be included the sampling data, starting time, the
weather condition at current and the filter paper ID with the initial weight;
Ÿ
After sampling, the filter paper will be collected and transfer
from the filter holder of the HVS to a sealed envelope and sent to a local
HOKLAS accredited laboratory for quantifying.
3.4.7
All the sampled 24-hour TSP filters will be
collected and put into the filter envelope provided by the laboratory. The sample will be kept in normal air conditioned
room conditions, i.e. 70% HR (Relative Humidity) and 25oC and
delivery to the office within 48 hours and sent to laboratory for
analysis. The sampled filter will
be kept in the laboratory for six months prior to disposal.
3.4.8
The HVS used for 24-hour TSP monitoring will be calibrated before
the commencement for sampling, and after in two months interval for 1 point
checking of maintenance and six months interval for five points calibrate in
accordance with the manufacturer’s instruction using the NIST-certified
standard calibrator (Tisch Calibration Kit Model
TE-5025A) to
establish a relationship between the follow recorder meter reading in cfm
(cubic feet per minute) and the standard flow rate, Qstd,
in m3/min. Motor brushes
of HVS will be regularly replaced of about five hundred hours per time.
Construction
Noise
3.4.9
As referred to in the Technical Memorandum (TM) issued under the
NCO, sound level meters in compliance with the International Electrotechnical
Commission Publications 651: 1979 (Type 1) and 804:1985 (Type 1) specifications
shall be used for carrying out the noise monitoring. Immediately prior to and
following each noise measurement the accuracy of the sound level meter shall be
checked using an acoustic calibrator generating a known sound pressure level at
a known frequency. Measurements may be accepted as valid only if the
calibration levels from before and after the noise measurement agree to within
1.0 dB.
3.4.10
All noise measurements will be performed with the meter set to
FAST response and on the A-weighted equivalent continuous sound pressure level (Leq). Leq(30
min) in six consecutive Leq(5
min) measurements will be used as the monitoring parameter for the time period
between 07:00-19:00 hours on weekdays and 3 sets of
consecutive Leq(5min) on restricted hours i.e. public
holiday or Sunday throughout the baseline period.
3.4.11
The sound level meter will be mounted on a tripod at a height of
1.2 m and placed at the assessment point and oriented such that the microphone
is pointed to the site with the microphone facing perpendicular to the line of
sight. The windshield will be fitted for all measurements. Where a
measurement is to be carried out at a building, the assessment point would
normally be at a position 1 m from the exterior of the building façade. Where a
measurement is to be made for noise being received at a place other than a
building, the assessment point would be at a position 1.2 m above the ground in
a free-field situation, i.e. at least 3.5 m away from reflective surfaces such
as adjacent buildings or walls.
3.4.12
Immediately prior to and following each noise measurement the
accuracy of the sound level meter will be checked using an acoustic calibrator
generating a known sound pressure level at a known frequency. Measurements will be accepted as valid
only if the calibration level from before and after the noise measurement
agrees to within 1.0 dB.
3.4.13
Noise measurements will not be made in fog, rain, wind with a
steady speed exceeding 5m/s or wind with gusts exceeding 10m/s. The wind speed will
be checked with a portable wind speed meter capable of measuring the wind speed
in m/s.
3.4.14
The calibration
certificates of monitoring equipment of air quality and noise and the HOKLAS-Accreditation
certificate of the testing laboratory is shown in Appendices E and F.
Meteorological
Information
3.4.15
The meteorological information including wind direction, wind speed,
humidity, rainfall, air pressure and temperature etc. during baseline monitoring is
extracted from the closest Hong Kong Observatory Station. To obtain the most appropriate meteorological information
where available,
Air Temperature/Pressure and Relative Humidity will be extracted from Tai Po
Station and wind speed and direction will be extracted from Tai Mei Tuk Station.
3.5.1
The baseline monitoring data were handled by the
ET’s in-house data
recording and management system.
3.5.2
The monitoring data recorded in the equipment were downloaded
directly from the equipment at the end of each monitoring day. The downloaded monitoring data were
input into a computerized database properly maintained by the ET. The laboratory results were input
directly into the computerized database and checked by personnel other than
those who input the data.
3.5.3
For monitoring parameters that require laboratory analysis, the
local laboratory shall follow the QA/QC requirements as set out under the
HOKLAS scheme for the relevant laboratory tests.
4
Baseline Monitoring Results
4.1.1
The baseline monitoring schedules are presented in Appendix
G and the monitoring results are detailed in the following
sub-sections.
4.2.1
Baseline air quality monitoring was carried out form 7 June 2017 to 20 June 2017. The
results for 24-hour and 1-hour TSP are summarized in Tables 4-1 to 4-2. The 24-hour TSP data are shown in Appendix
I and the laboratory report record are
shown in Appendix J.
Table 4-1 Summary
of 24-hour and 1-hour TSP Monitoring Results – A4
|
Date
|
24-hour TSP (mg/m3)
|
1-hour TSP (mg/m3)
|
|
Date
|
Start Time
|
1st Measurement
|
2nd Measurement
|
3rd Measurement
|
|
7-Jun-17
|
17
|
7-Jun-17
|
9:40
|
26
|
21
|
18
|
|
8-Jun-17
|
14
|
8-Jun-17
|
13:11
|
34
|
36
|
34
|
|
9-Jun-17
|
14
|
9-Jun-17
|
13:16
|
33
|
32
|
32
|
|
10-Jun-17
|
13
|
10-Jun-17
|
13:15
|
40
|
40
|
36
|
|
11-Jun-17
|
16
|
11-Jun-17
|
13:18
|
34
|
40
|
37
|
|
12-Jun-17
|
15
|
12-Jun-17
|
10:37
|
33
|
39
|
38
|
|
13-Jun-17
|
22
|
13-Jun-17
|
14:32
|
30
|
31
|
29
|
|
14-Jun-17
|
29
|
14-Jun-17
|
13:21
|
28
|
27
|
29
|
|
15-Jun-17
|
22
|
15-Jun-17
|
13:31
|
35
|
31
|
37
|
|
16-Jun-17
|
22
|
16-Jun-17
|
13:02
|
69
|
57
|
63
|
|
17-Jun-17
|
17
|
17-Jun-17
|
14:16
|
40
|
40
|
41
|
|
18-Jun-17
|
22
|
18-Jun-17
|
9:14
|
49
|
48
|
41
|
|
19-Jun-17
|
11
|
19-Jun-17
|
13:39
|
42
|
46
|
38
|
|
20-Jun-17
|
22
|
20-Jun-17
|
13:37
|
37
|
41
|
47
|
|
Average
(Range)
|
18
(11-29)
|
Average
(Range)
|
38
(18-69)
|
Table 4-2 Summary
of 24-hour and 1-hour TSP Monitoring Results – A7
|
Date
|
24-hour TSP (mg/m3)
|
1-hour TSP (mg/m3)
|
|
Date
|
Start Time
|
1st Measurement
|
2nd Measurement
|
3rd Measurement
|
|
7-Jun-17
|
7
|
7-Jun-17
|
9:55
|
25
|
29
|
22
|
|
8-Jun-17
|
11
|
8-Jun-17
|
13:07
|
33
|
26
|
27
|
|
9-Jun-17
|
15
|
9-Jun-17
|
13:12
|
29
|
45
|
31
|
|
10-Jun-17
|
12
|
10-Jun-17
|
13:11
|
36
|
37
|
38
|
|
11-Jun-17
|
16
|
11-Jun-17
|
13:21
|
36
|
35
|
36
|
|
12-Jun-17
|
18
|
12-Jun-17
|
10:33
|
29
|
33
|
31
|
|
13-Jun-17
|
21
|
13-Jun-17
|
14:29
|
32
|
36
|
32
|
|
14-Jun-17
|
28
|
14-Jun-17
|
13:17
|
30
|
30
|
40
|
|
15-Jun-17
|
24
|
15-Jun-17
|
13:18
|
34
|
40
|
42
|
|
16-Jun-17
|
21
|
16-Jun-17
|
13:17
|
53
|
63
|
52
|
|
17-Jun-17
|
19
|
17-Jun-17
|
14:10
|
40
|
39
|
40
|
|
18-Jun-17
|
24
|
18-Jun-17
|
9:03
|
50
|
48
|
42
|
|
19-Jun-17
|
16
|
19-Jun-17
|
13:28
|
46
|
41
|
43
|
|
20-Jun-17
|
15
|
20-Jun-17
|
13:20
|
32
|
28
|
38
|
|
Average
(Range)
|
17
(7-28)
|
Average
(Range)
|
37
(22-63)
|
4.2.2
The meteorological data during the baseline monitoring period are summarized
in Appendix H.
Action/Limit Levels for Air
Quality
4.2.3
Following the criteria shown in Table 2-6 of this report, the proposed Action and Limit Levels for 24-hour
and 1-hour TSP are listed in Table 4-3.
Table 4-3 Action
and Limit Levels for Air Quality Monitoring for all Stations
|
Monitoring
Station
|
Action Level (mg /m3)
|
Limit Level (mg/m3)
|
|
1-hour TSP
|
24-hour TSP
|
1-hour TSP
|
24-hour TSP
|
|
A4
|
275
|
142
|
500
|
260
|
|
A7
|
274
|
141
|
500
|
260
|
Note: 1-hour
& 24-hour TSP Action Level = (Baseline × 1.3 + Limit level)/2
4.3.1
The baseline noise monitoring at noise monitoring locations N1, N2a, N3a and N4 was undertaken on 7 June 2017 to 23 June 2017. Since there was continuous rain during daytime on 17 June 2017, the scheduled
noise monitoring on 17
June 2017 at all stations were
cancelled and baseline period would be extended one day. Furthermore, in view of the unstable weather condition on
12 & 13 June 2017, two additional days of baseline
monitoring were conducted in order to collect a comprehensive
background noise level data. Hence,
the whole baseline noise monitoring was carried out from 7 June 2017 to 16 June
2017 and 18 June 2017 to 23 June 2017. The
measurement data are shown in Appendix I and summarized in Table 4-4.
Table
4-4 Summaries
of Noise Monitoring Results
|
Monitoring
Station
|
Normal day (Monday to
Saturday):
Daytime 0700-1900, Leq(30min)
|
Public Holiday or Sunday:
Daytime 0700-1900, Leq(15min)
|
|
Mean
|
Min
|
Max
|
Mean
|
Min
|
Max
|
|
N1
|
63
|
58
|
70
|
63
|
60
|
66
|
|
N2a
|
58
|
55
|
62
|
57
|
57
|
57
|
|
N3a
|
57
|
54
|
64
|
58
|
57
|
59
|
|
N4
|
59
|
57
|
64
|
63
|
61
|
64
|
Note:
(1)
Sound level meter set at N1 and
N3a are made free-field measurement, façade correction (+3dB(A))
has added according to acoustical principles and EPD guidelines.
(2)
Figures refer to the
measurement recorded at the designated station during the entire baseline
period for general reference.
4.3.2
The collected baseline noise monitoring
data can represent the background condition of monitoring locations without the
impact arising from construction of the project. It therefore served as reference data to
compare with the impact monitoring data in order to facilitate the
investigation when Limit Level exceedance is triggered during the construction
phase of the project.
Action/Limit Levels for Noise
4.3.3
The Action and Limit Levels for construction noise are shown in Table 4-5.
Table 4-5 Action
and Limit Levels of Construction Noise Monitoring
|
Time Period
|
Action Level
|
Limit Level in dB(A)
|
|
0700-1900 hours on normal
weekdays
|
When one documented complaint is received
|
75 dB(A)
|
Air Quality
Possible Influence of Seasonal Changes
4.4.1
The baseline monitoring was conducted between 7 June 2017 and 23 June 2017
during typical Hong Kong wet seasons.
The baseline data so collected therefore represent the baseline air
quality of the wet season immediately prior to commencement of the
Project. They may not reflect the
air quality conditions of dry seasons in Hong Kong, which are normally
significantly different.
4.4.2
It is therefore recommended that the interpretation of the air
quality monitoring data should take into account the influence of the seasonal
changes, and the baseline conditions should be regularly reviewed, in
particular during seasonal changes.
5.1.1
The baseline monitoring program was carried out during the period
between 7 June 2017 and 23 June 2017 at the proposed monitoring locations by the ET according to the approved EM&A
Manual. During the baseline
monitoring, there were no construction activities undertaken under this
Project.
5.1.2
Based on the baseline monitoring results, the recommended
environmental performance criteria for air quality and construction noise are
summarized as follows:
|
Recommended Action & Limit Levels of Air Quality
|
|
Monitoring Station
|
Action Level (mg /m3)
|
Limit Level (mg/m3)
|
|
1-hour TSP
|
24-hour TSP
|
1-hour TSP
|
24-hour TSP
|
|
A4
|
275
|
142
|
500
|
260
|
|
A7
|
274
|
141
|
500
|
260
|
|
Recommended Action &
Limit Levels of Construction Noise
|
|
Monitoring Location
|
Action Level
|
Limit Level
|
|
0700-1900 hours on normal weekdays
|
|
N1, N2a, N3a & N4
|
When one or more documented complaints are received
|
75 dB(A)
|
