Drainage Services Department (DSD) has awarded the contract for the
Design and Construction of Tsuen Wan Drainage Tunnel (hereafter referred to as
the “Project”) to Maeda-CREC-SELI Joint Venture (MCSJV). MCSJV has appointed Hyder Consulting
Limited (HCL) as the Environmental Team (ET) to undertake the Environmental
Monitoring and Audit (EM&A) works in accordance with the Environmental
Monitoring and Audit Manual (EM&A Manual) and Environmental Permit (EP)
(Permit No. FEP-01/275/2007). The
notified date of commencement work is January 2008. This Monthly EM&A Report summarises the EM&A works
undertaken during the period of May 2008.
According to the EM&A Manual, there are four designated air
quality monitoring locations, five designated noise monitoring locations and
four water quality monitoring locations during the construction phase: (i) Sik
Sik Yuen Ho Fung College (ASR 1, NSR 1 and Intake I-1); (ii) Hong Hoi Chee Hong
Temple (ASR 3, NSR 3 and Intake I-2); (iii) Squatters (NSR 6 and Intake I-3);
(iv) Beach Tower (Long Beach Gardens) (ASR 8, NSR 8 and Outfall O-1); and (v)
Greenview Terrace (Block 1) (ASR 9, NSR 9 and Outfall O-1).
During non-restricted hours, major construction activities
undertaken by the Contractor at TWDT were site clearance, hoarding erection
& fencing erection, tree survey & transplanting, slope stabilization,
site office formation and pre-construction survey. No construction activities were undertaken during restricted
hours.
No Action / Limit Levels exceedance of air quality and noise
monitoring was recorded in the reporting month.
Two limit
levels exceedances of DO were recorded at I-1-C on 7 May 2008 and I-2-C on 9
May 2008. Three
limit levels exceedances of SS were recorded at I-1-C on 23 and 28 May 2008 and
at I-3 on 26 May 2008 respectively during the reporting month. However these exceedances were caused
by natural fluctuation and were not related to the Project’s construction
activities since no construction activities were undertaken on the scheduled
monitoring dates above.
In the reporting month, no C&D material was disposed of to
public fill at Tuen Mun. A total
of 19.435m3 C&D waste were disposed of to NENT Landfill and 70m3
inert C&D material were reused in the Contract. A total of 100kg of paper/cardboard
were recycled and no chemical waste was disposed of in the reporting
month. In addition, no metals were
generated.
In this reporting month, bi-weekly site inspections and monthly site
audit were carried out by ET and Independent Environmental Checker (IEC)
respectively to ensure proper implementation of environmental mitigation
measures specified in the EM&A Manual and compliance with environmental
legislation. All observations,
which were recorded on the inspection checklists were passed to the Contractor
together with the ET’s recommendations.
No non-compliance was received in the reporting month.
No environmental complaints were received during the reporting
month.
No summons and prosecution were received in this reporting month.
The major construction works for the upcoming three months are:
·
Site clearance;
·
Hoarding & fencing erection;
·
Trees survey & transplanting;
·
Slope stabilization;
·
Site office formation; and
·
Pre-construction survey.
An alternative monitoring location was proposed to the Contractor on
21 May 2008 to replace the air quality and noise monitoring location at Intake
2 due to its inaccessibility.
Relocation of monitoring location is upon confirmation from DSD.
The Drainage Services Department (DSD)
proposes to construct a tunnel of an internal diameter of 6.5m and length
5.13km, with the purpose to alleviate the flooding risk in Tsuen Wan and Kwai
Chung.
This project is a Designated Project under
Schedule 2 Part I Category Q, of the Environmental Impact Assessment Ordinance (EIAO) as part of
the proposed Tsuen Wan Drainage Tunnel (TWDT) passes underneath the existing
Tai Mo Shan Country Park. An
Environmental Impact Assessment (EIA) Study has therefore been undertaken to
provide information on the nature and extent of environmental impacts arising
from the construction and operation of the proposed designed project and
related activities taking place concurrently. From the EIA the recommendations for monitoring contained
herein, are made.
The Maeda
- CREC - SELI Joint Venture (MCSJV) was awarded by DSD with the Contract –
Design and Construction of Tsuen Wan Drainage Tunnel.
Hyder was commissioned by the MCSJV as the ET
to implement an EM&A program in accordance with the EM&A Manual. The proposed tunnel section flows from the
junction of Shing Mun Road and Wo Yi Hop Road and discharges to south of Yau
Kom Tau underneath Castle Peak Road as shown in Appendix A.
The construction works of the Project commenced on January 2008. This is the second
monthly EM&A report summarising the impact monitoring results and audit
findings of the EM&A program during the reporting month in May 2008.
2.1
Project Organization and
Management Structure
The organization chart and lines of communication with respect to
the on-site environmental management are shown in Appendix B.
2.2
Construction Progress
This report marks the second month of the
civil works contract. It is
anticipated that the overall project programme from the detail design to
completion of all civil works shall take approximately 54 months. The construction programme is presented
in Appendix C.
The major construction activities undertaken in the reporting month
are:
·
Site clearance;
·
Hoarding & fencing erection;
·
Tree survey &
transplanting;
·
Slope
stabilisation;
·
Site
office formation; and
·
Pre-construction
survey.
As confirmed by the Contractor, there were no construction
activities undertaken at TWDT during the restricted hours.
2.3
Mitigation Measures
The environmental mitigation measures implemented and their status are
given in Appendix D.
2.4
Status of License and
Permit
A summary of relevant permits and licences for the Project is given
in Appendix E.
3
Summary of EM&A Requirement
3.1
Air Quality
3.1.1
Air Quality Parameters
1-hour Total Suspended Particulates (TSP)
levels are measured at the designated air monitoring locations in accordance
with the EM&A Manual.
Monitoring under typical weather conditions (with no adverse weather
such as typhoon signal or rain storm warning) is undertaken at each monitoring
location every six days.
Information such as date of monitoring, duration, weather condition,
equipment used and monitoring results are recorded on the field data sheet
developed for the Project. The
monitoring results are presented in Section 4.
3.1.2
Monitoring Methodology
1-hour TSP monitoring is carried out three
times every six days using HVASs and follows the standard sampling method as
set out in High Volume Method for Total Suspended Particulates, Part 50 Chapter
1 Appendix B, Title 40 of the Code of Federal Regulations of the USEPA.
After sampling, the filter paper loaded with
dust is kept in a clean and tightly sealed plastic bag. The filter paper is
then re-conditioned in a dessicator for 24 hours before obtaining the weight
under laboratory conditions.
The average concentration of the suspended
particulates is calculated based on the following information obtained from
monitoring:
·
Flow
rate
·
Weight
of the filter paper before and after sampling
·
Sampling
period indicated by the elapsed-time meter
All samples should be kept in good condition
(i.e. stored in sealed plastic bags, with brief description of the monitoring
dates and locations) for a period of 6 months before disposal. Sample analysis will be carried out by ALS Technichem (HK) Pty Limited (HOKLAS Registration Number 066).
3.1.3
Monitoring
Equipment and Calibration
High Volume Air Samplers (HVASs) are used for
1-hour TSP monitoring to comply with the USEPA specifications in Appendix B
Part 5 - Reference Method for the Determination of Suspended Particulate matter
in the Atmosphere (High-Volume Method) of the Code of Federal Regulation dated
June 1, 1991.
All HVASs are calibrated before commencement
of monitoring using standard orifice 5-points calibration method with orifice
calibrator to determine the actual flow rate of each HVAS. This shall be used for the calculation
of the TSP level. Calibration Kit
Model - TE5025A is used for calibration of the HVAS. Recalibration of the HVAS shall be carried out after motor
maintenance, at least once every six months, which is about the expected life
of carbon brush. The
air quality monitoring equipment used during the reporting month is shown in Table 3‑1Table 3‑1 below.
The calibration certificates are included in Appendix F.
|
Equipment Type
|
Model
|
Serial Number
|
Calibration Orifice Number
|
Location
|
|
HVAS
|
BM2000HX
|
4994
|
517N
|
ASR 1
|
|
HVAS
|
BM2000HX
|
5875
|
517N
|
ASR 3
|
|
HVAS
|
TE5005X
|
0390
|
517N
|
ASR 8
|
|
HVAS
|
TE5005X
|
0646
|
517N
|
ASR 9
|
Table 3‑1 Air
Quality Monitoring Equipment
3.1.4
Monitoring
Location
Four
designated air quality monitoring locations were identified in the contract
specific EM&A manual. They are
listed in Table 3‑2Table 3‑2 below and shown in Appendix G.
|
Monitoring Station ID
|
|
|
|
ASR1
|
Sik Sik Yuen Ho Fung College
|
G/F
|
|
ASR3
|
Hong Hoi Chee Hong Temple
|
Podium
|
|
ASR8
|
Beach Tower (Long Beach Gardens)
|
G/F
|
|
ASR9
|
Greenview Terrace (Block 1)
|
G/F
|
Table 3‑22
Air Quality Monitoring Locations
3.1.5
Action
and Limit Levels
The
Action and Limit Levels for the 1-hour TSP monitoring is shown in Table 3‑3Table 3‑3. In case
exceedances of Action and/or Limit levels for air quality occur, Event
Contingency Plans (ECPs) would be implemented. The ECPs for Action and Limit levels exceedances are shown
in Table 3‑4Table 3‑4.
|
Station
|
1-hr TSP Level in μg/m3
|
|
Action Level
|
Limit Level
|
|
ASR 1
|
307
|
500
|
|
ASR 3
|
327
|
500
|
|
ASR 8
|
337
|
500
|
|
ASR 9
|
329
|
500
|
Table 3‑33 Action
& Limit Levels for Air Quality
|
EVENT
|
ACTION
|
|
ET
|
IEC
|
SOR
|
CONTRACTOR
|
|
ACTION LEVEL
|
|
Exceedance for one
sample
|
·
Identify source, investigate the causes of exceedance
and propose remedial measures;
·
Inform IEC and SOR;
·
Repeat measurement to confirm finding;
·
Increase monitoring frequency to daily.
|
·
Check monitoring data submitted by ET;
·
Check Contractor’s working method.
|
·
Notify Contractor.
|
·
Rectify any unacceptable practice;
·
Amend working methods if appropriate.
|
|
Exceedance for two
or more consecutive samples
|
·
Identify source;
·
Inform IEC and SOR;
·
Advise SOR on the effectiveness of the proposed
remedial measures;
·
Repeat measurements to confirm findings;
·
Increase monitoring frequency to daily;
·
Discuss with IEC and Contractor on remedial actions
required;
·
If exceedance continues, arrange meeting with IEC and
SOR;
·
If exceedance stops, cease additional monitoring.
|
·
Check monitoring data submitted by ET;
·
Check Contractor’s working method;
·
Discuss with ET and Contractor on possible remedial
measures;
·
Advise the ET on the effectiveness of the proposed
remedial measures;
·
Supervise Implementation of remedial measures.
|
·
Confirm receipt of notification of exceedance in
writing;
·
Notify Contractor;
·
Ensure remedial measures properly implemented.
|
·
Submit proposals for remedial to SOR within 3 working
days of notification;
·
Implement the agreed proposals;
·
Amend proposal if appropriate.
|
|
LIMIT LEVEL
|
|
Exceedance for one
sample
|
·
Identify source, investigate the causes of exceedance
and propose remedial measures;
·
Inform IEC, SOR, Contractor and EPD;
·
Repeat measurement to confirm finding;
·
Increase monitoring frequency to daily;
·
Assess effectiveness of Contractor’s remedial actions
and keep IEC, EPD and SOR informed of the results.
|
·
Check monitoring data submitted by ET;
·
Check Contractor’s working method;
·
Discuss with ET and Contractor on possible remedial
measures;
·
Advise SOR on the effectiveness of the proposed
remedial measures;
·
Supervise implementation of remedial measures.
|
·
Confirm receipt of notification of exceedance in
writing;
·
Notify Contractor;
·
Ensure remedial measures properly implemented.
|
·
Take immediate action to avoid further exceedance;
·
Submit proposals for remedial actions to IEC within 3
working days of notification;
·
Implement the agreed proposals;
·
Amend proposal if appropriate.
|
|
Exceedance for two
or more consecutive samples
|
·
Notify IEC, SOR, Contractor and EPD;
·
Identify source;
·
Repeat measurement to confirm findings;
·
Increase monitoring frequency to daily;
·
Carry out analysis of Contractor’s working procedures
to determine possible mitigation to be implemented;
·
Arrange meeting with IEC and SOR to discuss the
remedial actions to be taken;
·
Assess effectiveness of Contractor’s remedial actions
and keep IEC, EPD and SOR informed of the results;
·
If exceedance stops, cease additional monitoring.
|
·
Discuss amongst SOR, ET, and Contractor on the
potential remedial actions;
·
Review Contractor’s remedial actions whenever
necessary to assure their effectiveness and advise SOR accordingly;
·
Supervise the implementation of remedial measures.
|
·
Confirm receipt of notification of exceedance in
writing;
·
Notify Contractor;
·
In consultation with the IEC, agree with the Contractor
on the remedial measures to be implemented;
·
Ensure remedial measures properly implemented;
·
If exceedance continues, consider what portion of the
work is responsible and instruct the Contractor to stop that portion of work
until the exceedance is abated.
|
·
Take immediate action to avoid further exceedance;
·
Submit proposals for remedial actions to IEC within 3
working days of notification;
·
Implement the agreed proposals;
·
Resubmit proposals if problem still not under
control;
·
Stop the relevant portion of works as determined by
SOR until the exceedance is abated.
|
Table 3‑44 Event/Action
Plan for Air Quality
3.2
Noise
3.2.1
Noise Parameters
The construction
noise level is measured in terms of equivalent A-weighted sound pressure level
(Leq) measured in decibels (dB(A)). Monitoring of Leq(30 min) is carried out at the
noise monitoring locations on a weekly basis during normal construction working
hours (0700-1900 hours from Monday to Saturday except public holidays). For all other time periods (i.e.
restricted hours), Leq(5 min) would be employed for comparison with
the Noise Control Ordinance (NCO) criteria if necessary.
The two statistical sound levels L10
and L90: the level exceeded for 10 and 90 percent of the time
respectively, are also recorded during monitoring. Major noise sources observed, both on-site and off-site, are
recorded on the field data sheet.
All measurements are recorded to the nearest 0.1 dB(A) and presented in
round numbers in this report. Results
are presented in Section 4.
3.2.2
Monitoring Methodology
Sound level meters,
which comply with the International Electrotechnical Commission Publication
651: 1979 (Type 1) and 804: 1985 (Type 1) specifications as referred to the
Technical Memorandum (TM) issued under the Noise Control Ordinance, are
used. Noise levels for the
A-weighted levels Leq(30min), L10 and L90 are
measured throughout the impact monitoring. Average, by sound power, of six consecutive 5 minutes
readings is used to provide Leq(30 min) for non-restricted hours
(07:00-19:00 hours from Monday to Saturday except public holidays). A facade correction of 3dB(A) is
applied to measurements that are carried out under free field conditions.
During the impact monitoring, parameters such as
dates, weather condition, equipment used, measurement results and major noise
sources are recorded on the field data record sheet. Monitoring would not be carried out in the presence of fog,
rain or strong wind with a steady speed exceeding 5 m/s. In relation to the monitored noise
levels, other noise sources such as road traffic might make a significant
contribution to the overall noise environment. Therefore, noise monitoring activities would take into
account such influencing factors, which were not presented during the baseline
monitoring period.
3.2.3
Monitoring
Equipment and Calibration
Bruel & Kjaer
(B&K) Precision Integrating Sound Level Meters of Type 2238 in compliance
with the International Electrotechnical Commission Publication 651: 1979 (Type
1) and 804: 1985 (Type 1) Specifications, stated in the Technical Memorandum
(TM) issued under the NCO, is used for noise monitoring.
Prior to and following each noise measurement,
the accuracy of the sound level meter is checked using an acoustic calibrator
(B&K Type 4231(S/N 1770806) generating a known sound pressure level at a
known frequency. Measurements are
considered as valid only if the calibration levels from before and after the
noise measurement agrees to within 1.0 dB(A). The sound level meters and
the calibrators shall be calibrated annually to ensure they perform to the same
level of accuracy as stated in the manufacturers specifications. The noise
monitoring equipment used during the reporting month is shown in Table 3‑5Table 3‑5
below. The calibration
certificates are included in Appendix F.
|
Equipment Type
|
Manufacturer
|
Type Number
|
Serial Number
|
Location
|
|
Sound Level Meter
|
Bruel & Kjaer
|
2238
|
2285726
|
NSR1, NSR3, NSR6, NSR8 and NSR9
|
|
Sound Level Calibrator
|
Bruel & Kjaer
|
4231
|
1770806
|
NSR1, NSR3, NSR6, NSR8 and NSR9
|
Table 3‑55 Noise
Monitoring Equipment
3.2.4
Monitoring
Location
Five designated noise
monitoring locations were identified in the contract specific EM&A
manual. They are listed in Table 3‑6Table 3‑6 below and shown in Appendix G.
|
Monitoring
Station ID
|
Name of
Premises
|
Floor Level
|
|
NSR1
|
Sik Sik Yuen
Ho Fung College
|
G/F
|
|
NSR3
|
Hong Hoi Chee
Hong Temple
|
Podium
|
|
NSR6
|
Squatters
|
G/F
|
|
NSR8
|
Beach Tower
(Long Beach Gardens)
|
G/F
|
|
NSR9
|
Greenview
Terrace (Block 1)
|
G/F
|
Table 3‑66 Noise
Monitoring Locations
3.2.5
Construction Groundborne Noise
Prediction of
construction groundborne noise indicates the criteria will be achieved at most
NSRs except exceedances are predicted at Hong Hoi Chee Hong Temple (NSR3) and
Squatters (NSR6). It is
recommended to restrict the TBM operation in non-restricted period (i.e. 0700 -
1900) at these NSRs. In order to
ensure proper control of groundborne noise is executed by the contractor, a
monitoring requirement is recommended at the Hong Hoi Chee Hong Temple at
Intake 2 and Squatters at Intake 3 for compliance checking. According to the monitoring schedule,
TBM operation would be carried out for about 3 months in the vicinity of Hong
Hoi Chee Hong Temple at Intake 2 and Squatters at Intake 3. If groundborne noise criterion is
exceeded, the monitoring shall continue daily until acceptance has been
restored against the criterion.
Otherwise the monitoring can be discontinued.
The criterion include
TM for the Assessment of Noise from Places other than Domestic Premises, Public
Places or Construction Sites (TM-Places) under the NCO stipulates that noise
transmitted primarily through the structural elements of building, or
buildings, shall be 10 dB(A) less than the relevant ANLs. Daytime groundborne construction
noise criterion of 60 dB(A) therefore applies with reference to TM-EIAO 70
dB(A) criterion for schools and taking account of the minus 10 dB(A)
requirement under the NCO TM-Places.
Following the same principle for groundborne noise criteria, groundborne
construction noise levels inside domestic premises relying on open window for
ventilation will be limited to 65 dB(A), with reference to the daytime airborne
noise criterion of 75 dB(A) in accordance with TM-EIAO.
3.2.6
Action
and Limit Levels
The Action and Limit
levels for construction noise are defined in Table 3‑7Table 3‑7. If non-compliance of the criteria
occurs, actions in accordance with the Action Plan in Table 3‑8Table 3‑8 would be carried out.
|
Time Period
|
Action
|
Limit
|
|
0700
– 1900 hrs on normal weekdays
|
When one documented complaint is
received
|
75
dB(A)*
|
|
0700
– 2300 hrs on holidays; and
1900
– 2300 hrs on all other days
|
70
dB(A)
|
|
2300
– 0700 hrs of next day
|
55
dB(A)
|
* For
educational establishments the limit level shall be 70dB(A) and reduced to
65dB(A) during examination periods between 0700-1900 hrs on normal weekdays.
Table 3‑77 Action
& Limit Levels for Noise
|
Event
|
Action
|
|
ET Leader
|
IEC
|
SOR
|
Contractor
|
|
Action Level
|
1. Notify IEC and the Contractor.
2. Carry out investigation.
3. Report the results of investigation to IEC and the Contractor.
4. Discuss with the Contractor and formulate remedial measures.
5. Increase monitoring frequency to check mitigation measures.
|
1. Review with analysed results submitted by ET.
2. Review the proposed remedial measures by the Contractor and advise SOR
accordingly.
3. Supervise the implement of remedial measures.
|
1. Confirm receipt of notification of exceedance in writing.
2. Notify the Contractor.
3. Require the Contractor to propose remedial measures for the analysed
noise problem.
4. Ensure remedial measures are properly implemented.
|
1. Submit noise mitigation proposals to IEC.
2. Implement noise mitigation proposals.
|
|
Limit Level
|
1. Identify the source.
2. Notify IEC, SOR, EPD and the Contractor.
3. Repeat measurement to confirm findings.
4. Increase monitoring frequency.
5. Carry out analysis of Contractor’s working procedures to determine
possible mitigation to be implemented.
6. Inform IEC, SOR, and EPD the causes & actions taken for the
exceedances.
7. Assess effectiveness of the Contractor’s remedial actions and keep
IEC, EPD and SOR informed of the results.
8. If exceedance stops, cease additional monitoring.
|
1. Discuss amongst SOR, ET Leader and the Contractor on the potential
remedial actions.
2. Review the Contractor’s remedial actions whenever necessary to assure
their effectiveness and advise SOR accordingly.
3. Supervise the implementation of remedial measures.
|
1. Confirm receipt of notification of exceedance in writing.
2. Notify the Contractor.
3. Require the Contractor to propose remedial measures for the analysed
noise problem.
4. Ensure remedial measures are properly implemented.
5. If exceedance continues, consider what activity of the work is responsible
and instruct the Contractor to stop that activity of work until the
exceedance is abated.
|
1. Take immediate action to avoid further exceedance.
2. Submit proposals for remedial actions to IEC within 3 working days of
notification.
3. Implement the agreed proposals.
4. Resubmit proposals if problem still not under control.
5. Stop the relevant activity of works as determined by the SOR until the
exceedance is abated.
|
Table 3‑88 Event/Action
Plan for Noise
3.3
Water Quality
As there is no dredging or
reclamation required for the project, the water quality impact would be
insignificant with the protection measures recommended in Section 5.6 of the
EIA report. However in view of the
sensitive nature of the rivers/streams and bathing beaches in the Study Area,
it is suggested that a programme of monitoring should be established to confirm
the mitigation measures are protecting these water bodies.
3.3.1
Water
Quality Parameters
Monitoring for Dissolved Oxygen (DO),
temperature, turbidity, pH and suspended solids (SS) should be undertaken at
designated monitoring locations. It should be noted that
DO, temperature, turbidity and pH should be measured in-situ whereas SS is
assayed in a laboratory.
In association with the water quality
parameters, other relevant data should also be measured, such as monitoring
location/position, time, weather conditions, and any special phenomena and
description of work underway at the construction site etc.
3.3.2
Monitoring
Methodology
In
accordance with the EM&A Manual, the water quality monitoring for all
specified parameters shall be measured at all designated monitoring locations
including control points at an interval of 3 days per week. DO,
temperature, turbidity, pH and SS shall be undertaken at designated monitoring
locations.
It should be
noted that water
samples for all monitoring parameters should be collected, stored, preserved
and analysis according to Standard Methods, APHA 17 ed. and/or methods agreed
by the Director of Environmental Protection.
Each
sample shall be analysed in accordance with the APHA Standard Methods for the
Examination of Water and Wastewater, 18th edition, or an equivalent method
approved by the EPD. If an
in-house or non-standard method is proposed, details of the method verification
may require to be submitted to the EPD.
In any circumstance, the sample testing should comply with a
comprehensive quality assurance and quality control programme. The laboratory should be prepared to
demonstrate the quality programmes to the EPD when requested.
3.3.3
Monitoring
Equipment and Calibration
All the water samples collected should be
transferred to clearly labelled and
pre-cleaned sample containers with necessary preservatives immediately after
collection. The sample containers
should be provided by HOKLAS accredited laboratory. Sufficient quantity of samples should be collected for all
laboratory analyses. Following
sampling, samples should be stored in a cool box at temperature of between 0
and 4oC, and transported to the laboratory within the sample
retention time as advised by the laboratory under proper chain-of-custody
system.
The water quality monitoring equipment used during the reporting month
is shown in Table 3‑9Table 3‑9 below.
|
Equipment Type
|
Manufacturer
|
Model
|
Quantity
|
|
PH / DO / Temperature Meter
|
WTW
|
PH/Oxi 340i
|
1
|
|
Tuibidimeter
|
EUTECH
|
TN-100
|
1
|
Table 3‑99 Water
Quality Monitoring Equipment
All pH meters, DO meters
and turbidimeters shall be checked and calibrated prior to use. DO meters and turbidimeters shall be
calibrated by a laboratory accredited under HOKLAS or any other international
accreditation scheme, and subsequently re-calibrated at 3 monthly intervals
throughout all stages of the water quality monitoring. Responses of sensors and electrodes
shall be checked with certified standard solutions before each use. Wet bulb calibrations for all DO meters
shall be carried out before measurement at each monitoring location. For the on site calibration of field
equipment, BS 127:1993, "Guide to field and on-site test methods for the
analysis of waters" should be observed. The calibration certificates shall be attached in
the next monthly report.
3.3.4
Monitoring
Location
Four designated monitoring locations were identified in the contract specific EM&A Manual for water quality monitoring. While the
construction of the outfall does not require dredging or reclamation,
monitoring of water quality is only required during which the rip rap is
placed. These four monitoring stations are listed
in Table 3‑10Table 3‑10 below and shown in
Appendix G.
|
Monitoring
Station ID
|
Name of
Premises
|
|
I-1
|
Intake I-1
|
|
I-1-C
|
Control of
Intake I-1
|
|
I-2
|
Intake I-2
|
|
I-2-C
|
Control of
Intake I-2
|
|
I-3
|
Intake I-3
|
|
I-3-C
|
Control of
Intake I-3
|
|
O-1 (FT)
|
Outfall
1During Flood Tide
|
|
O-1 (ET)
|
Outfall
1During Ebb Tide
|
|
O-1-C (FT)
|
Control of
Outfall O-1 During Flood Tide
|
|
O-1-C (ET)
|
Control of
Outfall O-1 During Ebb Tide
|
Table 3‑1010 Water
Quality Monitoring Locations
Note that there are two control stations for Outfall O-1, one for
sampling during flood tide and one for sampling during ebb tide. Only one of those control stations for
Outfall O-1 shall be sampled during each sampling. Control station to be sampled will be determined base on the
tidal information provided by the Hong Kong Observatory.
3.3.5
Action and Limit
Levels
The Action and Limit
levels for water quality monitoring parameters are defined in Table 3‑11Table 3‑11. In case of any exceedance,
appropriate action will be undertaken in accordance with the Event and Action
Plan as described in Table 3‑12Table 3‑12.
|
Parameters
|
Action
|
Limit
|
|
DO in mg/l
(Surface, Middle &
Bottom)
|
Surface & Middle
5%-ile of baseline
data for surface and middle layer.
Bottom
5%-ile of baseline
data for bottom layer.
|
Surface & Middle
4mg/l except 5mg/l for
FCZ or
1%-ile of baseline
data for surface and middle layer
Bottom
2mg/l or 1%-ile of
baseline data for bottom layer
|
|
SS in mg/l
(depth-averaged)
|
95%-ile of baseline
data or 120% of upstream control station’s SS at the same tide of the same
day
|
99%-ile of baseline or
130% of upstream control station’s SS at the same tide of the same day and
specific sensitive receiver water quality requirements (e.g. required
suspended solids levels for concerned sea water intakes)
|
|
Turbidity (Tby) in NTU
(depth-averaged)
|
95%-ile of baseline
data or 120% of upstream control station’s Tby at the same tide of the same
day
|
99%-ile of baseline or
130% of upstream control station’s Tby at the same tide of the same day
|
Notes:
·
For DO, non-compliance of the water quality limits occurs when
monitoring result is lower than the limits.
·
For SS and Tby, non-compliance of the water quality limits
occurs when monitoring result is higher than the limits.
·
All the figures given in the table are used for reference only
and the EPD may amend the figures whenever it is considered as necessary.
Table 3‑1111 Action/Limit
Levels for Water Quality
|
Event
|
ET Leader
|
IEC
|
SOR
|
Contractor
|
|
Action Level being exceeded by one sampling day
|
1. Repeat in-situ
measurement to confirm finding;
2. Identify
source(s) of impact;
3. Inform IEC and
Contractor;
4. Check monitoring
data, all plant, equipment and Contractor’s working methods;
5. Discuss
mitigation measures with IEC and Contractor; and
6. Repeat
measurement on next day of exceedance.
|
1. Discuss with ET
and Contractor on the mitigation measures;
2. Review proposals
on mitigation measures submitted by Contractor and advise the SOR
accordingly; and
3. Assess the
effectiveness of the implemented mitigation measures.
|
1. Discuss with IEC
on the proposed mitigation measures; and
2. Make agreement on
the mitigation measures to be implemented.
|
1. Inform the SOR
and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Check all plant
and equipment;
4. Consider changes
of working methods;
5. Discuss with ET
and IEC and propose mitigation measures to IEC and SOR; and
6. Implement the
agreed mitigation measures.
|
|
Action Level being exceeded by more than one
consecutive sampling day
|
1. Repeat in-situ
measurement to confirm finding;
2. Identify
source(s) of impact;
3. Inform IEC and
Contractor;
4. Check monitoring
data, all plant, equipment and Contractor’s working methods;
5. Discuss
mitigation measures with IEC and Contractor;
6. Ensure mitigation
measures are implemented;
7. Prepare to
increase the monitoring frequency to daily; and
8. Repeat
measurement on next day of exceedance.
|
1. Discuss with ET
and Contractor on the mitigation measures;
2. Review proposals
on mitigation measures submitted by Contractor and advise the SOR
accordingly; and
3. Assess the
effectiveness of the implemented mitigation measures.
|
1. Discuss with IEC
on the proposed mitigation measures;
2. Make agreement on
the mitigation measures to be implemented; and
3. Assess the
effectiveness of the implemented mitigation measures.
|
1. Inform the
Engineer and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Check all plant
and equipment;
4. Consider changes
of working methods;
5. Discuss with ET
and IEC and propose mitigation measures to IEC and SOR within 3 working days;
and
6. Implement the
agreed mitigation measures.
|
|
Limit Level being exceeded by one sampling day
|
1. Repeat in-situ
measurement to confirm finding;
2. Identify
source(s) of impact;
3. Inform IEC,
Contractor and EPD;
4. Check monitoring
data, all plant, equipment and Contractor’s working methods;
5. Discuss
mitigation measures with IEC, SOR and Contractor;
6. Ensure mitigation
measures are implemented; and
7. Increase the
monitoring frequency to daily until no exceedance of Limit level.
|
1. Discuss with ET
and Contractor on the mitigation measures;
2. Review proposals
on mitigation measures submitted by Contractor and advise the SOR
accordingly; and
3. Assess the
effectiveness of the implemented mitigation measures.
|
1. Discuss with IEC,
ET and Contractor on the proposed mitigation measures; and
2. Request
Contractor to critically review the working methods;
3. Make agreement on
the mitigation measures to be implemented; and
4. Assess the
effectiveness of the implemented mitigation measures.
|
1. Inform the
Engineer and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Check all plant
and equipment;
4. Consider changes
of working methods;
5. Discuss with ET
and IEC and SOR and propose mitigation measures to IEC and SOR within 3
working days; and
6. Implement the
agreed mitigation measures.
|
|
Limit Level being exceeded by more than one consecutive sampling day
|
1. Repeat in-situ
measurement to confirm finding;
2. Identify
source(s) of impact;
3. Inform IEC,
Contractor and EPD;
4. Check monitoring
data, all plant, equipment and Contractor’s working methods;
5. Discuss
mitigation measures with IEC, SOR and Contractor;
6. Ensure mitigation
measures are implemented; and
7. Increase the
monitoring frequency to daily until no exceedance of Limit level for two
consecutive days.
|
1. Discuss with ET
and Contractor on the mitigation measures;
2. Review proposals
on mitigation measures submitted by Contractor and advise the SOR
accordingly; and
3. Assess the
effectiveness of the implemented mitigation measures.
|
1. Discuss with IEC,
ET and Contractor on the proposed mitigation measures; and
2. Request
Contractor to critically review the working methods;
3. Make agreement on
the mitigation measures to be implemented;
4. Assess the
effectiveness of the implemented mitigation measures; and
5. Consider and
instruct, if necessary, the Contractor to slow down or to stop all or part of
the marine work until no exceedance of Limit Level.
|
1. Inform the SOR
and confirm notification of the non-compliance in writing;
2. Rectify
unacceptable practice;
3. Check all plant
and equipment;
4. Consider changes
of working methods;
5. Discuss with ET
and IEC and SOR and propose mitigation measures to IEC and SOR within 3
working days;
6. Implement the
agreed mitigation measures; and
7. As directed by the
Engineer, to slow down or to stop all or part of the marine work or
construction activities.
|
Table
3‑1212 Event/Action
Plan for Water Quality
4.1
Air Quality
The
air quality monitoring schedule of the reporting period is given in Appendix
H.
4.1.1
1-hr TSP Monitoring
Results of
1-hours TSP level are shown in Table 4‑1Table 4‑1. All measurements are recorded to the
nearest 0.1mg/m3 and presented in round numbers in this
report. Detailed results,
including weather conditions, and graphical presentations are presented in
Appendix I.
|
Station
|
Monitoring
Date
|
Monitoring
Result (mg/m3)
|
Action/Limit
Levels (mg/m3)
|
|
ASR 1
|
02-May-08
|
66
|
307/500
|
|
35
|
|
69
|
|
08-May-08
|
65
|
|
84
|
|
89
|
|
14-May-08
|
133
|
|
73
|
|
112
|
|
20-May-08
|
63
|
|
43
|
|
49
|
|
26-May-08
|
79
|
|
69
|
|
69
|
|
31-May-08
|
143
|
|
106
|
|
136
|
|
ASR 3
|
02-May-08
|
100
|
327/500
|
|
44
|
|
44
|
|
07-May-08 (1)
|
90
|
|
48
|
|
75
|
|
13-May-08
|
Voided (2)
|
|
66
|
|
57
|
|
21-May-08 (3)
|
20
|
|
52
|
|
66
|
|
30-May-08 (4)
|
113
|
|
156
|
|
141
|
|
31-May-08
|
112
|
|
Voided (5)
|
|
155
|
|
ASR 8
|
02-May-08
|
47
|
337/500
|
|
55
|
|
45
|
|
08-May-08
|
66
|
|
131
|
|
83
|
|
14-May-08
|
248
|
|
197
|
|
158
|
|
20-May-08
|
36
|
|
30
|
|
27
|
|
26-May-08
|
95
|
|
88
|
|
9
|
|
31-May-08
|
114
|
|
64
|
|
100
|
|
ASR 9
|
02-May-08
|
8
|
329/500
|
|
55
|
|
41
|
|
08-May-08
|
105
|
|
70
|
|
101
|
|
14-May-08
|
62
|
|
168
|
|
127
|
|
20-May-08
|
99
|
|
62
|
|
65
|
|
26-May-08
|
68
|
|
44
|
|
47
|
|
31-May-08
|
- (6)
|
|
- (6)
|
|
- (6)
N/A (4)
|
Note:
(1)
As the temple was inaccessible on 08 May, the measurement was
set on 07 May
(2)
The first measurement was void as there is no weight difference
between the initial and final weight of filter paper
(3)
As the temple was inaccessible on 20 May, the measurement was
set on 21 May
(4)
The monitoring was originally scheduled on 26 May but was
postponed to 30 May because the temple was inaccessible from 26 - 29 May
(5)
The second measurement was void as the final weight was greater
than the initial weight of filter paper
(6)
No result was recorded on 31 May due to power failure at ASR9
Table 4‑1 Air
Quality Monitoring Results
No
exceedances of 1-hr TSP Action / Limit Level were recorded during the reporting
month.
4.2
Noise
The
noise monitoring schedule of the reporting period is given in Appendix H. Results of measured noise level, in terms of Leq(30min),
during the construction are shown in Table 4‑2Table 4‑2. Detailed results, including weather
conditions and graphical presentation are presented in Appendix I.
|
Station
|
Monitoring Date
|
Leq (30 min) dB(A)
|
Limit Levels dB(A)
|
L10 dB(A)
|
L90 dB(A)
|
|
NSR
1
|
2-May-08
|
62
|
70
|
64
|
60
|
|
8-May-08
|
65
|
69
|
63
|
|
14-May-08
|
65
|
68
|
62
|
|
20-May-08
|
67
|
69
|
66
|
|
26-May-08
|
70
|
72
|
68
|
|
NSR
3
|
2-May-08
|
60
|
75
|
63
|
58
|
|
8-May-08
|
60
|
62
|
57
|
|
14-May-08
(1)
|
-
|
-
|
-
|
|
20-May-08
(2)
|
-
|
-
|
-
|
|
26-May-08
(2)
|
-
|
-
|
-
|
|
NSR
6
|
2-May-08
|
62
|
64
|
59
|
|
8-May-08
|
64
|
65
|
61
|
|
14-May-08
|
63
|
64
|
60
|
|
20-May-08
(2)
|
-
|
-
|
-
|
|
26-May-08
(2)
|
-
|
-
|
-
|
|
NSR
8
|
2-May-08
|
64
|
66
|
61
|
|
8-May-08
|
61
|
63
|
58
|
|
14-May-08
|
60
|
61
|
58
|
|
20-May-08
(2)
|
-
|
-
|
-
|
|
26-May-08
(2)
|
-
|
-
|
-
|
|
NSR
9
|
2-May-08
|
66
|
68
|
62
|
|
8-May-08
|
67
|
70
|
62
|
|
14-May-08
|
64
|
67
|
61
|
|
20-May-08
(2)
|
-
|
-
|
-
|
|
26-May-08
(2)
|
-
|
-
|
-
|
Note:
(1)
No result was recorded on 14 May as
the NSR was inaccessible.
(2)
No result was recorded on 20 and 26 May due to the bad weather.
Table 4‑22 Noise
Monitoring Results
No exceedances of Action / Limit Level were recorded
during the reporting month.
4.3
Water Quality Monitoring
The
water quality monitoring schedule of the reporting period is given in Appendix
H. Results of measured water quality parameters
during the reporting month are shown in Table 4‑3Table 4‑3.
Two limit levels
exceedances of DO were recorded at I-1-C on 7 May 2008 and I-2-C on 9 May
2008. Three
limit levels exceedances of SS were recorded at I-1-C on 23 and 26 May 2008 and
at I-3 on 26 May 2008 respectively during the reporting month. However these exceedances at I-1-C,
I-2-C and I-3 were caused by natural fluctuation and were not related to the
Project’s construction activities since no construction activities were
undertaken on the
scheduled monitoring dates above.
Detailed results,
including weather conditions, and graphical presentations are presented in
Appendix I.
Interim Notifications
of Environmental Quality Limits Exceedances is summarized in Appendix J.
