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Contract No. CM 04/2024 – Outlying Islands Sewerage Stage 2 – South
Lantau Sewerage Works – Environmental Team Services (2025 - 2027) |
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Quarterly Environmental Monitoring, and
Audit Report for: February to April 2025 Revision
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______________ Ting
Po Chung, Ivan Environmental
Team Leader Report
Date: |
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Content:
1.2 Environmental
Monitoring & Audit Programme
1.3 Quarterly
Environmental Monitoring & Audit Report
2. Basic project
Information and Environmental Status
2.3 Works
undertaken during the Reporting quarter
3. Environmental
Monitoring and Audit (“EM&A”) Requirement
3.1 Summary of Monitoring Parameters
3.2 Environmental quality performance
limits (Action and Limit levels); and Results Summary
3.3 Implementation Status of
Environmental Mitigation Measures
3.4 Complaints, Non-Compliance, and
Notification of Summons and Prosecution
4.1 Environmental
Monitoring and Audits
4.2 Implementation
of Environmental Mitigation Measures
Tables:
Table 2.1: Contact Details of Key Personnel
Table 3.1: Summary of Impact EM&A Requirements
Table 3.2: Action and Limit Levels for Noise Monitoring
Table 3.3: Action and Limit Levels for Water Quality
Table 3.4: Summary of Ecological Impact
Monitoring
Table 3.5: Summary of Quantities of Waste Material in the Reporting Quarter
Figures:
Figure
3.1 Locations of Noise Monitoring Station
Figure
3.2 Locations of Water Quality
Monitoring Station
Appendices:
Appendix
3.1 Noise Monitoring Graphical
Presentations
Appendix
3.2 Marine Water Quality Monitoring Graphical
and Summary of Exceedance Presentations
This Quarterly
Environmental Monitoring and Audit (“EM&A”) Report summarise project
monitoring, and auditing data, with full interpretation illustrating the
acceptability or otherwise of any environmental impacts, and identification or
assessment of the implementation status of agreed mitigation measures,
including monitoring results, and findings of the EM&A Programme, along
with findings recorded during the site Inspections, and audits, reports of
Complaints, Notifications of Summons, and Successful Prosecutions, and other
necessary observations obtained within this reporting quarter from 1 February
2025 to 30 April 2025.
Key Construction
Works in the Reporting quarter
San Shek Wan Sewage
Treatment Works (“SSWSTW”)
·
Excavation, and site formation
·
Superstructure Reinforced Concrete (“RC”) works
·
Retaining wall construction
·
Dredging, and diffuser construction
Pui O Sewage Pumping
Station (“POSPS”)
·
Excavation, and Excavation, and Lateral Support (”ELS”) work
·
Electrical, and Mechanical (“E&M”)
Lo Uk Tsuen, Pui O
·
Excavation, Sewer Laying, and Construction of
Manhole
South Lantau Road
·
Excavation, Sewer Laying, and Construction of
Manhole
Chi Ma Wan Road
·
Excavation, Sewer Laying, and Construction of
Manhole
·
Trenchless drilling works
Environmental
Monitoring, and Audit Progress
The EM&A
Programme is implemented in accordance with the EM&A Manual under the EIA
Report. A summary of the monitoring activities during this reporting quarter as
below:
|
Monitoring Activity |
Monitoring Date |
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February 2025 |
March 2025 |
April 2025 |
|
|
Noise |
7, 15, 19-20, and 25 |
3-4, 15, 17, 21-22
and 27-28 |
2-3, 8-9, 15-16, 22, and 28 |
|
Water Quality |
1, 4, 6, 8, 11, 13, 15,
18, 20, 22, 25, and 27 |
1, 4, 6, 8, 11, 13, 15,
18, 20, 22, 25, 27, and 29 |
1, 3, 5, 8, 10, 12, 15,
17, 22, 24, 26, and 29 |
|
Nursery visit for
transplanted trees |
24 |
24 |
23 |
|
Site Inspection |
5, 12, 17, 24 |
3, 10, 17, 24, and 31 |
7, 14, 23, and 28 |
Breaches of Action,
and Limit Levels
A summary of
environmental exceedances for this reporting quarter is as follows:
|
Environmental
Monitoring |
Parameters |
Action Level |
Limit Level |
|
Noise |
Leq (30 min) |
0 |
0 |
|
Water
Quality |
Suspended
solids level (“SS”) |
0 |
0 |
|
Turbidity
level |
0 |
0 |
|
|
Dissolved
oxygen level (“DO”) |
0 |
0 |
Ecological Impact
Monitoring
Transplanting of the
trees of Aquilaris sinensis was completed on 26 April
2022. Maintenance works for trees in holding nursery have commenced.
4 trees found (1 no.
of Aquilaria sinensis, and 3 nos. of Gmelina chinensis) within the site of
SSWSTW which are considered to be the plant species
with conservative importance for temporarily transplanted to the nursery at Kam Tin, and eventually be transplanted to POSPS.
The weekly site
audit was carried out by ET include checking whether good site practices are
being properly implemented by the Contractor.
The extent of the
work site boundaries was checked by the ET during the weekly site audit.
Complaints,
Notification of Summons and Prosecution
No environmental
complaint was recorded in the reporting quarter.
No notification of
summons and successful prosecution regarding construction works were recorded
in the reporting quarter.
Reporting Changes
Upon conclusion of Contract No: SD 15/2022
Outlying Island Sewerage Stage 2 – South Lantau Sewage Works – Environmental
Team Services (2023 – 2024), the subsequent contract, Contract No. CM 04/2024
Outlying Islands Sewerage Stage 2 – South Lantau Sewerage Works – Environmental
Team Services (2025-2027), has been awarded to Umwelt Consulting Limited
(“UCL”) starting 1 February 2025. As such the environmental team leader (“ETL”)
appointed for the Project has been updated to Mr. Ting Po Chung, Ivan since 1
February 2025. His contact details has been updated in
Table 2.1.
1.1.1
The Environmental Protection Department (“EPD”)
completed the Outlying Islands Sewerage Master Plan (“SMP”) Study in 1994 and
drew up a SMP for Lantau Island and other outlying islands. The proposed
sewerage works of the SMP were divided into 2 stages. The Stage 2 Works of the SMP were
subsequently reviewed by EPD under the Outlying Islands Sewerage Master Plan
Stage 2 Review (SMP Review Study) in 2001.
1.1.2
The proposed sewerage works for South Lantau
were further reviewed in 2008 under the Review of Sewerage Scheme for South
Lantau (Review Study). According to the Review Study, the proposed sewerage
works for South Lantau would serve the unsewered areas of Shui Hau, Tong Fuk,
Cheung Sha, San Shek Wan, Pui O and Ham Tin.
1.1.3
The Outlying Islands Sewerage Stage 2 – South
Lantau Sewerage Works, herein referred to as “the Project”, referred to the
sewerage works for South Lantau that would serve the unsewered areas of Shui
Hau, Tong Fuk, Cheung Sha, San Shek Wan, Pui O and Ham Tin.
1.1.4
The Project mainly comprises of the following
items:
a)
Construction of a secondary sewage treatment
works (“STW”) at San Shek Wan in South Lantau;
b)
Construction of sewage pumping station (“SPS”)
at Pui O, San Shek Wan, Cheung Sha, Cheung Fu Street, Shui Hau and Tong Fuk;
c)
Construction of about 1.4km of twin submarine
outfalls with a diameter of 350mm for the disposal of treated effluent from the
STW at San Shek Wan;
d)
Construction of about 10.1km of gravity sewers
with diameters ranging from 150mm to 375mm along South Lantau Road and Chi Ma
Wan Road and at Pui O; and
e)
Construction of about 3.1km of twin rising mains
with a diameter of 200mm to 250mm along South Lantau Road and Chi Ma Wan Road.
1.2.1
An Environmental Impact Assessment (“EIA”) was
subsequently prepared to review the potential environmental impact that would
be due to the Project during its construction works and operational works. The
EIA Report was submitted and approved on 24 April 2017, and Environmental Permit
(“EP”) No. EP-538/2017 was subsequently granted on 13 July 2017.
1.2.2
The EM&A Programme is therefore implemented
in accordance with the EM&A Manual under the EIA Report.
1.2.3
Umwelt Consulting Limited (“UCL”) has been
appointed to work as the Environmental Team (“ET”) under EP No. EP-538/2017 to
implement the EM&A programme as stipulated in the EM&A Manual of the
approved EIA Report for the Outlying Islands Sewerage Stage 2 – South Lantau
Sewerage Works (Register No.: AEIAR-210/2017).
1.3.1
This Quarterly EM&A Report summarise project
monitoring and auditing data, with full interpretation illustrating the
acceptability or otherwise of any environmental impacts and identification or
assessment of the implementation status of agreed mitigation measures,
including monitoring results and findings of the EM&A Programme, along with
findings recorded during the site Inspections and audits, reports of
Complaints, Notifications of Summons and Successful Prosecutions, and other
necessary observations obtained within this reporting quarter form February 2025 to
April 2025.
2.1.1
Drainage Services
Department (“DSD”) is the project proponent and the permit holder of the
Project. For the construction phase of the Project, Contractor(s), ET and
Independent Environmental Checker (“IEC”) are appointed to manage and control
environmental issues. Key personnel and contact particulars are summarized in Table 2.1.
2.1.2
Upon conclusion of
Contract No: SD 15/2022 Outlying Island Sewerage Stage 2 – South Lantau Sewage
Works – Environmental Team Services (2023 – 2024), the subsequent contract,
Contract No. CM 04/2024 Outlying Islands Sewerage Stage 2 – South Lantau
Sewerage Works – Environmental Team Services (2025-2027), has been awarded to
Umwelt Consulting Limited (“UCL”) starting 1 February 2025. As such the environmental
team leader (“ETL”) appointed for the Project has been updated to Mr. Ting Po
Chung, Ivan since 1 February 2025. His contact details has been updated in Table 2.1.
2.1.3
There are no other
reporting changes in the reporting quarter.
Table 2.1: Contact
Details of Key Personnel
|
Party |
Role |
Post |
Name |
Contact No. |
Contact Fax |
|
Drainage Services Department |
The Engineer for the Contract |
Engineer |
Mr. KK Chan |
2594 7297 |
3104 6426 |
|
Binnies Hong Kong Limited |
Engineer’s Representative |
Resident Engineer |
Mr. Kevin Chan |
3529 3003 |
- |
|
Kwan Lee – Chun Wo
Joint Venture |
Contractor |
Sub Agent |
Mr. Daniel Chu |
6737 6701 |
2744 6937 |
|
Environmental Supervisor |
Ms. Joey Pang |
6978 2876 |
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Environmental Supervisor |
Mr. Philip Wong |
6908 8920 |
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SMEC Hong Kong |
IEC |
IEC |
Ms. Kitty Lee |
3995 8140 |
3422 3631 |
|
Umwelt Consulting Limited |
ET |
ET Leader |
Mr. Ivan Ting |
3756 9590 |
3582 3310 |
2.2.1
The proposed sewerage
works will collect the sewage generated from the unsewered areas of Shui Hau,
Tong Fuk, Cheung Sha, San Shek Wan, Pui O and Ham Tin in South Lantau (i.e.
within the Project Catchment Area) and convey it to a proposed sewage treatment
works at San Shek Wan for treatment and disposal into outer bay of Pui O / Chi
Ma Wan via a submarine outfall.
2.2.2
The Project was divided into 3 contracts. The current contract, Contract No.
DC/2020/02 - Construction of San Shek Wan Sewage Treatment Works, Associated
Submarine Outfall and Pui O Sewerage Works (“the Contract”) would have the following implementations. The works site of the Contract
is also given in Figure 2.1.
2.2.3
The major components
of the Contract under Environmental Permit (“EP”) (EP No. EP-538/2017)
comprises:
a) Construction of a secondary sewage treatment works
(“STW”) at San Shek Wan in South Lantau;
b) Construction of a sewage pumping station (“SPS”) at
Pui O, San Shek Wan, Cheung Sha and Cheung Fu Street;
c) Construction of about 1.4km of submarine outfall
with a diameter of 350mm for the disposal of treated effluent from the STW at
San Shek Wan;
d) Construction of about 10.1km of gravity sewers with
diameters ranging from 150mm to 375mm along South Lantau Road and Chi Ma Wan road and at Pui O; and
e) Construction of about 3.1km twin rising mains with
a diameter of 200mm to 250mm along South Lantau Road and Chi Ma Wan Road.
2.3.1
In the reporting quarter, the principal work
activities conducted are as follow:
a)
Excavation, and site formation
b)
Superstructure Reinforced Concrete (“RC”) works
c)
Retaining wall construction
d)
Dredging, and diffuser construction
a)
Excavation, and Excavation, and Lateral Support (”ELS”)
work
b)
Electrical, and Mechanical (“E&M”)
a)
Excavation, Sewer Laying, and Construction of Manhole
a)
Excavation, Sewer Laying, and Construction of Manhole
a)
Excavation, Sewer Laying, and Construction of Manhole
b)
Trenchless drilling works
3.1.1
The EM&A programme requires environmental monitoring, noise
monitoring, water quality monitoring, and ecology as specified in the approved
EM&A Manual.
3.1.2
A summary of Impact EM&A requirements is presented in Table 3.1. The
locations of noise monitoring stations, and water quality monitoring stations are shown in Figure 3.1 and
Figure 3.2 respectively.
Table 3.1: Summary of Impact EM&A Requirements
|
Environmental
Monitoring Aspects |
Parameters and
Unit |
Monitoring Station |
Frequencies |
Remarks |
|
Noise |
Leq (30mins), L10 (30mins)
and L90 (30mins) |
N12a, N12b,
N13, N14, N15b, N16a, N16b, and N17 |
At least once per
week |
Daytime on normal
weekdays (0700-1900 hrs). |
|
Water Quality |
Dissolved Oxygen,
mg/L Temperature, °C Salinity, 0/00 Turbidity, NTU Suspended Solids,
mg/L pH |
CE, CF, SR4,
SR5, SR6, SR9, SR10, SR12, and SR15 |
Three times per
week during mid-ebb, and mid-flood tides |
Samples are
collected at 3 depths (1 m below water, mid-depth, and 1 m above seabed)
shall be collected. Where the water
depth is less than 6 m, in which case the mid-depth station may be omitted. Should the water
depth be less than 3 m, only the mid-depth station will be monitored |
3.2.1
A-weighted equivalent continuous sound pressure level (“Leq”) over a period of 30 minutes (“Leq 30min”) shall be used as the
monitoring parameter for construction noise monitoring. Supplementary
information for data auditing, statistical results such as L10, and
L90 should also be recorded for reference.
3.2.2
For impact monitoring of construction works, noise monitoring should be
undertaken on weekly basis. Six consecutive Leq
(5min) between 07:00-19:00 hours on normal weekdays is taken in this
EM&A Programme.
3.2.3
The Action and Limit Levels for noise monitoring are given as in Table 3.2.
Table 3.2: Action and Limit Levels for Noise Monitoring
|
Monitoring
Station ID |
Monitoring
Location |
Action Level |
Limit Level |
|
N12a |
Lo Uk Tsuen |
When one documented complaint is received from
any one of the noise sensitive receivers |
75 dB(A) |
|
N12b |
Lo Uk Tsuen |
75 dB(A) |
|
|
N13 |
Pui O San Wai
Tsuen |
75 dB(A) |
|
|
N14 |
South Lantau
Community Centre |
75 dB(A) |
|
|
N15b |
Pui O Lo Wai Tsuen |
75 dB(A) |
|
|
N16a |
Residences at Ham
Tin |
75 dB(A) |
|
|
N16b |
Residences at Ham
Tin |
75 dB(A) |
|
|
N17 |
Bui O Public
School |
70 dB(A) / 65
dB(A) 1 |
Note:
1. The Limit Level for N17 is 70 dB(A) for
being an educational institution. The Limit Level is reduced to 65 dB(A) during
school examination period.
3.2.4
No exceedance was recorded for the reporting quarter. The detailed
results and graphical plot for noise monitoring is given in Appendix 3.1.
3.2.5
In construction phase, the levels of dissolved oxygen (“DO”), temperature,
turbidity, and salinity should be measured in-situ while suspended solids
(“SS”) is determined by laboratory analysis.
3.2.6
The Action and Limit Levels for water quality monitoring are given as in
Table 3.3.
Table 3.3: Action and Limit Levels for Water Quality
|
Parameters |
Action Level |
Limit Level |
|
DO in mg/L 1 |
Surface, and Middle Level: |
Surface, and Middle Level: |
|
Turbidity in NTU
(Depth-averaged 2) 3 |
14.4 NTU and |
23.5 NTU and |
|
SS in mg/L (Depth-averaged 2)
3 |
13.1 mg/L and |
30.4 mg/L and |
Notes (with proposed amendments in AL/LL in
underlined text):
1. For DO, non-compliance of the water quality
limits occurs when monitoring result is lower than the limits.
2. “Depth-averaged” is calculated by taking the
arithmetic means of reading of all 3 depths
3. For SS, and turbidity, non-compliance of the
water quality limits occurs when monitoring result is higher than the limits.
4. Action Level, and Limit Level with 95%-ile / 99%-ile derived from
baseline data “and” 20% / 30% exceedance of control station proposed in
Baseline Monitoring Report.
3.2.7
No exceedance was recorded for the reporting quarter. The detailed
results and graphical plot for water quality monitoring is given in Appendix
3.2.
3.2.8
Monitoring in the form of regular site inspections should be carried out
to ensure ecological measures in the form of tree transplantation, and
establishment are being implemented, and effective for plant species of
conservation importance (e.g. Aquilaria sinensis).
3.2.9
Transplanting works for plant species, Aquilaris
sinensis, was completed on 26 April 2022. Maintenance works for trees in
holding nursery have commenced.
3.2.10 Monitoring of maintenance
works for the transplanted plant species was conducted at the holding nursery
while in the reporting period.
3.2.11 As per latest version of
PTP, four tree found (1 no. of Aquilaria sinensis, and
3 nos. of Gmelina chinensis) within the site of SSWSTW which are
considered to be the plant species with conservative importance for
temporarily transplanted to the nursery at Kam Tin and eventually be
transplanted to POSPS.
3.2.12
Within this reporting
period, holding nursery visit for transplanted trees on 24 February, 24 March
and 28 July23
April 2025.
3.2.13
No non-compliance was
found during the site inspection while reminders on environmental measures were
recommended. Results and findings of these inspections in this reporting period
are listed below in Table 3.4.
Table 10.13.4: Summary of Ecological Impact Monitoring
|
Inspection
Date |
Reminder
and Recommendations |
Close-out
Date / Status |
|
24
February 2025 |
Nil |
-- |
|
|
Nil |
|
|
23
April 2025 |
The
contractor is reminded to properly install the tree label. |
7
May 2025 |
3.2.14
The quantities of waste for disposal in
present quarter are summarized in Table 3.5.
Table 3.5: Summary of
Quantities of Waste Material in the Reporting Quarter
|
Waste Type |
Quantity for Reporting Quarter |
Cumulative Quantity-to-Day |
|
Hard Rock and Large Broken Concrete (Inert), in
‘000m3 |
0 |
0 |
|
|
0 |
0 |
|
Reused in this Contract (Inert),in |
0 |
0 |
|
Reused in other
Projects (Inert), in ‘000m3 |
0 |
0 |
|
Disposal as Public
Fill (Inert), in ‘000m3 |
2.43 |
29.48789 |
|
Metals (in ‘000kg) |
0.0086 |
15.78377 |
|
Paper / Cardboard
Packing, in ‘000kg |
0.1121 |
1.03058 |
|
Plastics
in ‘000kg |
0.0024 |
0.10016 |
|
Chemical
Waste in ‘000kg |
0 |
0 |
|
General
Refuse in ‘000kg |
52.75 |
799.25 |
|
|
|
|
Note:
The
inert waste disposal record up to 7 April 2025 was based on the onsite record
from the contractor instead of the official record from the Mui Wo Public Fill
Reception Facility due to the maintenance of the weighting bridge. The
subsequent inert waste disposal record will adopt the recorded weight at the
Mui Wo Public Fill Reception Facility.
Further breakdown into
sub-group if considered applicable;
Disposed as public
fill estimated based on Contractor’s site record
3.3.1
The mitigation measures recommended in the
EIA Report has been implemented where applicable. The implemented mitigation
measures for the reporting quarter are listed below:
a)
Implementation of noise mitigation measures
in accordance with Construction Noise Mitigation Plan, including the use of
quality powered mechanical equipment, use of noise barriers, and locating noisy
equipment away from noise sensitive receivers as far as possible;
b)
Dust control during dust generating works,
including watering of construction works site, covering the stockpile stored on
site, provision of wheel-washing facilities for vehicles at the site entrance;
c)
Water quality mitigation measures including
the setting up of silt curtain at the marine works site, and maintained in good
condition during the marine works;
d)
Adopt surface drainage and sediment control
facilities for sewage installation in village and public roads;
e)
Adopt temporary drainage and sediment control
facilities on Site; and
f)
Proper waste handling, recycling and storage.
3.3.2
The implemented mitigation measures are
considered effective.
3.4.1
No environmental complaint was recorded in the
reporting quarter.
3.4.2
No environmental non-compliance was recorded in
the reporting quarter.
3.4.3
No notification of summons and successful
prosecution regarding construction works were recorded in the reporting
quarter.
4.1.1
Environmental monitoring
and audits including Noise, Water Quality, Ecology, and Site audits have been
conducted in the reporting quarter in accordance with the requirement
stipulated in the EM&A Manua.
Noise
Monitoring
4.1.2
Noise Monitoring has
been conducted at 8 of the designated monitoring locations where construction works has been conducted nearby during the reporting
period.
4.1.3
No action or limit
level exceedance was recorded in construction noise level in this reporting period.
Water
Quality Monitoring
4.1.4
Marine Water
Monitoring has been conducted at 9 designated monitoring locations during the reporting period.
4.1.5
No action or limit
level exceedances were recorded within the reporting period.
Ecological
Impact Monitoring
4.1.6
Transplanting of the
trees of Aquilaris sinensis was
completed on 26 April 2022. Maintenance works for trees in holding nursery have commenced.
4.1.7
As per latest version
of PTP, 4 tree found (1 no. of Aquilaria sinensis and
3 nos. of
Gmelina chinensis) within
the site of SSWSTW which are considered to be the plant species with conservative importance for temporarily transplanted to the
nursery at Kam Tin and eventually be
transplanted to Pui O Pumping Station.
4.1.8
The weekly site audit
was carried out by ET include checking whether good site practices are being properly implemented by the Contractor.
4.1.9
The extent of the
work site boundaries was checked by the ET during the weekly site audit.
4.1.10 No non-compliance was found during the site
inspection while reminders on environmental measures were recommended.
4.2.1
The mitigation measures recommended in the EIA Report has been
implemented where applicable. The implemented mitigation measures are
considered effective.