f
Contents
2.5 LANDSCAPE AND VISUAL Monitoring
2.8 IMPLEMENTATION STATUS OF
ENVIRONMENTAL MITIGATION MEASURES
2.9 Summary of Exceedances of the
Environmental Quality Performance Limit
2.10 Summary of
Complaints, Notification of Summons and Successful Prosecutions
Annex
B
ENVIRONMENTAL MITIGATION IMPLEMENTATION SCHEDULE
Annex
C
MONITORING SCHEDULE FOR THIS REPORTING PERIOD
Annex D Air Quality
Annex
D1 CALIBRATION
CERTIFICATES FOR DUST MONITORING EQUIPMENT
Annex
D2 24-HOUR
TSP MONITORING RESULTS
Annex
D3 EVENT
AND ACTION PLAN FOR AIR QUALITY MONITORING
Annex
D5 CERTIFICATES
OF THE QUALIFIED ODOUR PANELIST
Annex
D6 ODOUR
MONITORING RESULTS
Annex
D8 ambient
vocs, ammonia and h2s
monitoring results
Annex E Noise
Annex
E1
CALIBRATION CERTIFICATES FOR NOISE MONITORING EQUIPMENT
Annex
E2
NOISE MONITORING RESULTS
Annex
E3
EVENT AND ACTION PLAN FOR NOISE MONITORING
Annex F Water Quality
Annex
F1
CALIBRATION CERTIFICATES FOR SURFACE WATER QUALITY MONITORING EQUIPMENT
Annex
F2
SURFACE WATER QUALITY MONITORING RESULTS
Annex
F3
EVENT AND ACTION PLAN FOR WATER QUALITY MONITORING
Annex
F4
CALIBRATION CERTIFICATES FOR EFFLUENT QUALITY MONITORING EQUIPMENT
Annex
F5
LEACHATE LEVELS MONITORING RESULTS
Annex
F6
EFFLUENT QUALITY MONITORING RESULTS
Annex
F7
CALIBRATION CERTIFICATES FOR GROUNDWATER MONITORING EQUIPMENT
Annex
F8
GROUNDWATER MONITORING RESULTS
Annex G Landfill Gas
Annex G2 CALIBRATION CERTIFICATES FOR LANDFILL GAS MONITORING EQUIPMENT
Annex
G3 LANDFILL
GAS MONITORING RESULTS
Annex I MONITORING
SCHEDULE FOR THE NEXT REPORTING PERIOD
This
Monthly EM&A report presents the EM&A works carried out during the
period from 1 to 31 May
2025 for the Project in
accordance with the updated EM&A Manual.
No exceedance of Action and Limit
Levels for operation/restoration phase air quality monitoring was recorded in
the reporting period.
No
exceedance of Action and Limit Levels for operation/restoration phase noise
monitoring was recorded in the reporting period.
One
exceedance of the Limit
Levels for groundwater (Chemical Oxygen Demand (COD)) was recorded for water quality monitoring in the reporting
period. The groundwater (COD) exceedance at MWX-5 on 7 May 2025 is under investigation.
No
exceedance of Action and Limit Levels for operation/restoration phase landfill
gas monitoring was recorded in the reporting period.
There
were no complaints, notification of summons or prosecution recorded in the
reporting period.
There was
no reporting change in the reporting period.
Potential
environmental impacts arising from the upcoming construction/ operational
activities in the next reporting period of June 2025 are mainly associated with
potential surface water impact in the rainy season.
The SENT Landfill Extension (SENTX) forms an integral part in the
Strategic Plan in maintaining the continuity of landfill capacity in the Hong
Kong for the cost-effective and environmentally satisfactory disposal of waste.
The Environmental Impact Assessment (EIA) Report and the associated Environmental
Monitoring and Audit (EM&A) Manual for the construction, operation,
restoration and aftercare of the SENTX (hereafter referred to as “the Project”)
have been approved under the Environmental Impact Assessment Ordinance
(EIAO) in May 2008 (Register No.: AEIAR-117/2008) (hereafter referred to as the
approved EIA Report) and an Environmental Permit (EP-308/2008) (EP) was granted
by the Director of Environmental Protection (DEP) on 5 August 2008.
Since then,
applications for Variation of an Environmental Permit (No. VEP-531/2017) were
submitted to EPD and the Variation of Environmental Permits (EP-308/2008/A and
EP-308/2008/B) were granted on 6 January 2012 and 20 January 2017,
respectively, as the Hong Kong SAR Government has decided to reduce the scale
of the design scheme of SENTX assessed in the approved EIA Report and SENTX
will only receive construction waste. In May 2018, a Further Environmental
Permit (FEP) (FEP-01/308/2008/B) was granted to the SENTX’s contractor, Green
Valley Landfill, Limited (GVL). In February 2024, VEPs (EP-308/2008/C and
FEP-01/308/2008/C) were granted to the Environmental Infrastructure Division of
EPD and GVL, regarding updates on alternative measures to minimise surface
odour emission.
Afterwards, VEPs (EP-308/2008/D and FEP-01/308/2008/D) were granted to the
Environmental Infrastructure Division of EPD and GVL on 17 April 2025 for the
updates on the extension of waste boundary of SENTX area.
ERM-Hong
Kong, Limited (ERM) and Meinhardt Infrastructure and Environment Limited
(Meinhardt) are commissioned to undertake the roles of Environmental Team (ET)
and the Independent Environmental Checker (IEC), respectively, to undertake the
EM&A activities for the Project in accordance with the requirements
specified in the EP, updated EM&A Manual ([1]),
approved EIA Report ([2]) taking
account of the latest design and other relevant statutory requirements.
The SENTX
is a piggyback landfill, occupying the southern part of the existing SENT
Landfill (including its infrastructure area) and 13 ha of Tseung Kwan O (TKO)
Area 137. A layout plan of the SENTX is shown in Figure 1.1. Under the latest design, the SENTX has a
net void capacity of about 7.29 Mm3 and provides an additional
lifespan of about 6 years, commencing operation upon exhaustion of the SENT
Landfill. The SENTX will receive construction waste only.
The key
implementation milestones of the Project are indicatively summarised in Table
1.1. The construction works and operation of the Project commenced on 2
January 2019 and 21 November 2021, respectively.
Table 1.1 Estimated Key Dates of Implementation Programme
Key Stage of the Project |
Indicative Date |
Start construction |
2 January 2019 |
Commissioning of new infrastructure facilities |
2020 |
Demolition of existing infrastructure facilities |
2021 |
Start waste intake at SENTX |
21 November 2021 |
Estimated exhaustion date of SENTX |
2027 |
End of aftercare for SENTX |
2059 |
The major
construction works of the SENTX includes:
• Site formation at the TKO Area 137
and the existing infrastructure area at SENT Landfill;
• Construction of surface and
groundwater drainage systems;
• Construction of the leachate
containment and collection systems;
• Construction of new leachate and
landfill gas treatment facilities, site offices, maintenance yards at the new
infrastructure area;
• Construction of new pipelines to
transfer the leachate and landfill gas collected from the existing SENT
Landfill to the treatment facilities at the new infrastructure area;
• Construction of the site access and
new waste reception facilities; and
• Demolition of the facilities at the
existing SENT Landfill infrastructure area.
This is
the Monthly EM&A Report for the Project which summarises the key findings
of the EM&A programme during the reporting period from 1 to 31 May 2025 for
the construction and operation works.
The
organisation structure of the Project is presented in Figure 1.2.
Figure
1.2 Organisation Chart
Contact
details of the key personnel are summarised in Table 1.2 below.
Table 1.2 Contact Information of Key Personnel
Party |
Position |
Name |
Telephone |
Contractor (Green Valley Landfill Limited) |
Project Manager |
Carl Lai |
2706 8829 |
Environmental Team (ET) (ERM-Hong Kong, Limited) |
ET Leader |
Terence Fong |
2271 3156 |
Independent Environmental Checker (IEC) (Meinhardt Infrastructure and Environment Limited) |
IEC |
Claudine Lee |
2859 5409 |
The
programme of the construction is shown in Annex A. As informed by the Contractor, the major works
carried out in this reporting period include:
• Maintenance and improvement of
temporary surface water drainage; and
• Restoration of Phase 1, Phase 2,
Phase 3 and Phase 4 slopes.
The
implementation schedule of the mitigation measured recommended in the Updated
EM&A Manual is presented in Annex
B.
The status
for all environmental aspects are presented in Table 1.3. The
EM&A requirements remained unchanged during the reporting period.
Table
1.3 Summary of Status for the Environmental Aspects under the Updated
EM&A Manual
Parameters |
Status |
Air Quality |
|
Baseline Monitoring |
The results of baseline air quality monitoring were reported in Baseline Monitoring Report and Pre-operation Baseline Monitoring Report and submitted to EPD under EP Condition 3.3 |
Impact Monitoring |
On-going |
Noise |
|
Baseline Monitoring |
The results of baseline noise monitoring were reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.3 |
Impact Monitoring |
On-going |
Water Quality |
|
Baseline Monitoring |
The results of baseline surface water quality monitoring were reported in Baseline Monitoring Report and Pre-operation Baseline Monitoring Report and submitted to EPD under EP Condition 3.3 |
Impact Monitoring |
On-going |
Landfill Gas |
|
Impact Monitoring |
On-going |
Waste Management |
|
Waste Monitoring |
On-going |
Landscape and Visual |
|
Baseline Monitoring |
The results of baseline landscape and visual monitoring were reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.3 |
Operation Phase Audit |
On-going |
Site Environmental Audit |
|
Regular Site Inspection |
On-going |
Complaint Hotline and Email Channel |
On-going |
Environmental Log Book |
On-going |
Taking into account the operation works, impact monitoring of air
quality, noise, water quality, landfill gas and waste management were carried
out in the reporting period. The impact monitoring schedule of air quality,
noise, water quality and landfill gas monitoring are provided in Annex C.
The
EM&A programme also involved environmental site inspections and related
auditing conducted by the ET for checking the implementation of the required
environmental mitigation measures recommended in the approved EIA Report and
relevant EP submissions. To promote the environmental awareness and enhance the
environmental performance of the contractors, environmental trainings and
regular environmental management meetings were conducted during the reporting
period, which are summarized as below:
One environmental management meeting
was held with the Contractor, ET, IEC and EPD on 29 May 2025; and
Environmental toolbox trainings on
Renewable Energy and Air Pollution Control (NRMM) Regulation were provided on
16 May 2025 by the Contractor to the workers.
The status
of statutory environmental compliance with the EP conditions under the EIAO,
submission status under the EP and implementation status of mitigation measures
are presented in Table 1.4.
Table
1.4 Status of Submissions required under the EP and Implementation Status
of Mitigation Measures
EP Condition |
Submission / Implementation Status |
Status |
2.3 |
Management Organisation of Main Construction Companies |
Submitted and accepted by EPD. |
2.4 |
Setting up of Community Liaison Group |
Community Liaison Group was set up. |
2.5 |
Submission of Detailed Landfill Gas Hazard Assessment Report |
Submitted and accepted by EPD on 10 January 2019. |
2.6 |
Submission of Restoration and Ecological Enhancement Plan |
Submitted to EPD on 28 June 2019. |
2.7 |
Setting up of Trial Nursery |
Trial Nursery works was commenced on 28 August 2019. |
2.8 |
Advance Screen Planting |
Advance Screen Planting works were completed on 28 June 2019. |
2.9 |
Provision of Multi-layer Composite Liner System |
Under implementation. |
The
environmental licenses and permits (including EP, Water Pollution Control
Ordinance (WPCO) discharge license, registration as a chemical waste
producer, and construction noise permit) that are valid in the reporting period
are presented in Table 1.5. No non-compliance with environmental
statutory requirements was identified.
Table
1.5 Status of Statutory Environmental Requirements
Description |
Ref No. |
Status |
Environmental Permit |
EP-308/2008 |
Granted on 5 August 2008 |
Variation of Environmental Permit |
EP-308/2008/A |
Granted on 6 January 2012 |
EP-308/2008/B |
Granted on 20 January 2017 |
|
EP-308/2008/C |
Granted on 29 February 2024 |
|
EP-308/2008/D |
Granted on 17 April 2025 |
|
Further Environmental Permit |
FEP-01/308/2008/B |
Granted on 16 May 2018 |
FEP-01/308/2008/C |
Granted on 29 February 2024 |
|
FEP-01/308/2008/D |
Granted on 17 April 2025 |
|
Water Discharge License under WPCO (Permit Holder: GVL) |
Licence No.: WT10003277-2024 |
Validity from 23 August 2024 to 30
June 2026 |
Billing Account for Disposal of Construction Waste |
Chit Account Number: 5001692 |
Approved on 28 December 2005 |
Registration as a Chemical Waste Producer (Permit Holder: GVL) |
5296-839-G2228-01 |
Issued on 31 December 2015 |
Construction Noise Permit (Permit Holder: GVL) |
GW-RE0364-25 |
Validity from 1 April 2025 to 14
September 2025 |
The
EM&A programme for the Project required environmental monitoring for air
quality, noise, water quality and landfill gas as well as environmental site
inspections for air quality, noise, water quality, landfill gas, waste
management, and landscape and visual impacts. The EM&A requirements and
related findings for each component are summarised in the following sections.
According
to the updated EM&A Manual of the Project, impact dust monitoring (in term
of Total Suspended Particulates (TSP)) was carried out at the four designated
locations along the site boundary (i.e. AM1, AM2, AM3 and AM4) during the
operation/restoration phase, at a 6-day interval. Due to the maintenance works at the DP3 drainage channel
(Phase 1 & 2 Restoration Drainage Channel Construction) for the SENT
Landfill, AM2 was temporarily relocated started on 2 May 2025 to ensure that
the planned maintenance works can be carried out safely and smoothly. Upon
completion of the maintenance works at the DP3 drainage channel, the temporary
relocation of AM2 would be ceased, and AM2 would be restored back to its
original location.
The proposed temporary relocation of AM2 (named “AM2-TEMP”) has been agreed and
verified by the IEC and approved by EPD on 24 April 2025.
The Action
and Limit Levels of the dust monitoring is provided in Table 2.1 below.
Table
2.1 Action and Limit Levels for 24-hour TSP
Monitoring Station |
Action Level |
Limit Level |
AM1 - SENTX Site Boundary (North) |
• 260 µg m-³ |
• 260 µg m-³ |
AM2-TEMP
- SENTX Site Boundary (West, opposite DP3) |
||
AM3 - SENTX Site Boundary (West,
near RC15) |
||
AM4 - SENTX Site Boundary (West, near EPD building) |
High volume
air samplers (HVSs) in compliance with the specifications listed under Section
3.2.2 of the updated EM&A Manual were used to measure 24-hour TSP levels at
the dust monitoring stations. The HVSs were calibrated upon installation and
thereafter at bi-monthly intervals to check the validity and accuracy of the
results.
The
equipment used in the impact dust monitoring programme and monitoring locations
are summarised in Table 2.2 and illustrated in Figure 2.1a, respectively. Copies of the calibration
certificates for the equipment are presented in Annex D1.
Table
2.2 Dust Monitoring Details
Monitoring Station |
Location |
Parameter |
Frequency and Duration |
Monitoring Dates |
Equipment |
AM1 |
SENTX Site Boundary (North) |
• 24-hour TSP |
• Once every 6 days |
• 2, 8, 14, 20, 26 May 2025 |
• Tisch TE-5170 (S/N: 3976) |
AM2-TEMP |
SENTX Site
Boundary (West, opposite DP3) |
• Tisch TE-5170 (S/N: 3573) |
|||
AM3 |
SENTX Site Boundary (West, near RC15) |
• Tisch TE-5170 (S/N: 3572) |
|||
AM4 |
SENTX Site Boundary (West, near EPD building) |
· Tisch TE-5170 (S/N: 3957) |
The
schedule for dust monitoring during the reporting period is provided in Annex C.
The
monitoring results for 24-hour TSP are summarised in Table 2.3. The
detailed monitoring results and the graphical presentation of the 24-hour TSP
results at each monitoring location are provided in Annex D2.
Table
2.3 Summary of 24-hour TSP Monitoring Results in the Reporting Period
Monitoring Station Location |
Average 24-hr TSP Concentration (µg m-3) (Range in bracket) |
Action Level (µg/m3) |
Limit Level (µg/m3) |
AM1 - SENTX
Site Boundary (North) |
133 (63
– 186) |
260 |
260 |
AM2-TEMP
- SENTX Site Boundary (West, opposite DP3) |
176
(103 – 247) |
260 |
260 |
AM3 - SENTX Site Boundary (West,
near RC15) |
126 (72 – 181) |
260 |
260 |
AM4 - SENTX Site Boundary (West,
near EPD building) |
75 (45 – 99) |
260 |
260 |
The major dust sources in the reporting period included fugitive dust
emission from exposed area in SENTX as well as nearby operations of the TKO
Area 137 Fill Bank.
No Action and
Limit Levels exceedance was recorded for TSP monitoring in the reporting
period. No action is thus required to be undertaken in accordance with the
Event and Action Plan presented in Annex D3.
Meteorological
data obtained from the SENTX on-site meteorological monitoring station was used
for the dust monitoring and is shown in Annex D4. It is considered that meteorological data
obtained at the on-site meteorological monitoring station is representative of
the Project area and could be used for the operation/restoration phase dust
monitoring programme for the Project.
According
to the updated EM&A Manual of the Project, odour patrol was carried out
along the site boundary during the operation/ restoration phase.
During the
first month of operation, daily odour patrol (3 times per day) was conducted
jointly by the ET and the IEC. The odour intensity detected was based on that
determined by the IEC. In addition, an independent party (ALS Technichem (HK)
Pty Ltd.) was appointed to undertake odour patrol together with the ET and IEC
three times per week. During these patrols, the odour intensity detected was
based on that determined by the independent third party.
Reduction
of odour monitoring frequency from Period 1 (daily, three times per day) to
Period 2 (weekly) was approved by EPD on 4 February 2022. Weekly odour
patrol was conducted jointly by the ET and the IEC from 10 February 2022.
In addition, an independent party (ALS Technichem (HK) Pty Ltd.) was appointed
to undertake odour patrol together with the ET and IEC once every two
weeks.
Reduction
of odour monitoring frequency from Period 2 (weekly) to Period 3 (monthly) was
approved by EPD on 2 June 2022. Monthly odour patrol was conducted
jointly by the ET and the IEC from 28 June 2022. In addition, an
independent party (ALS Technichem (HK) Pty Ltd.) was appointed to undertake
odour patrol together with the ET and IEC quarterly. Furthermore, the odour
patrol route has been reviewed against the latest construction / operation
programme and approved by EPD on 17 June 2024.
The Action
and Limit Levels for odour patrol is provided in Table 2.4 below.
Table
2.4 Action and Limit Levels for Odour Patrol
Parameter |
Action Level |
Limit Level |
Perceived odour intensity and odour complaints |
· Odour intensity ≥ Class 2 recorded; or · One documented complaint received |
· Odour intensity ≥ Class 3 recorded on 2 consecutive patrol (a) (b)
|
Notes: (a) i.e. either Class 3-strong or Class 4-extreme odour intensity. (b) The exceedances of the odour intensity do not need to be recorded at the same location. |
Odour patrol was conducted by trained personnel/competent persons with a
specific sensitivity to a reference odour (i.e. on reference materials
n-butanol with the concentration of 50ppm in nitrogen (v/v)) in compliance with
Section 3.7.2 of the updated EM&A Manual patrolling and sniffing along the
SENTX Site boundary to detect any odour.
The odour
monitoring programme and patrol route are summarised in Table 2.5 and
illustrated in Figure 2.2
respectively. Copies of the certificates of the qualified odour
panelist are presented in Annex
D5.
Table
2.5 Odour Monitoring Details
Patrol Locations |
Parameters |
Patrol Frequency (a) |
Monitoring Dates |
Patrol along the SENTX Site Boundary (Checkpoints OP1 – OP17) |
Odour Intensity (see Table 2.6) |
Period 1 - First month of operation Daily, three times a day in the morning, afternoon and evening/night (between 18:00 and 22:00 hrs) conducted by the ET and the IEC
Three times per week on different days conducted by an independent third party together with the ET and IEC (b)
Period 2 - Three months following period 1 (c)
Weekly conducted by the ET and the IEC
Once every two weeks conducted by an independent third party together with the ET and IEC (b)
Period 3 - Throughout operation following period 2 (c) Monthly conducted by the ET and the IEC
Quarterly conducted by an independent third party together with the ET and IEC (b) |
Conducted by ET & IEC: 12 May 2025
Conducted by an independent third party, ET & IEC: - |
Notes: (a) Reduction of monitoring frequency will be subject to the monitoring results to demonstrate environmentally acceptable performance. (b) Patrol shall be scheduled so that they are carried out together with the patrols to be carried out jointly by the ET and the IEC. (c) Commencement of each period will be justified by the ET Leader and verified by the IEC and will be subject to agreement with the EPD (EIAO Authority) and Project Proponent. |
Table
2.6 Odour Intensity Level
Class |
Odour Intensity |
Description |
0 |
Not Detected |
No odour perceived or an odour so weak that it cannot be easily characterised or described. |
1 |
Slight |
Identified odour, slight |
2 |
Moderate |
Identified odour, moderate |
3 |
Strong |
Identified odour, strong |
4 |
Extreme |
Severe odour |
The
schedule for odour patrol during the reporting period is provided in Annex C.
The odour
monitoring results are summarised and provided in Table 2.7 and Annex D6, respectively.
Table
2.7 Summary of Odour Monitoring Results in the Reporting Period
Odour Checkpoints |
Odour Intensity Class |
Action Level |
Limit Level |
OP1 |
1 |
Odour intensity ≥ Class 2 recorded |
Odour intensity ≥ Class 3 recorded on 2 consecutive patrol |
OP2 |
0 |
||
OP3 |
0 |
||
OP4 |
0 |
||
OP5 |
0 |
||
OP6 |
0 |
||
OP7 |
0 |
||
OP8 |
0 |
||
OP9 |
0 |
||
OP10 |
0 |
||
OP11 |
0 |
||
OP12 |
0 |
||
OP13 |
0 |
||
OP14 |
0 |
||
OP15 |
0 |
||
OP16 |
1 |
||
OP17 |
0 |
The potential odour source in the
reporting period included the Cell 4X tipping area at SENTX and the nearby
vegetation. All the
odour monitoring results were below the Action and Limit Levels in the
reporting period. No action is thus required to be undertaken in accordance
with the Event and Action Plan presented in Annex D3.
According
to the updated EM&A Manual of the Project, the performance of the thermal
oxidiser, landfill gas flare and landfill gas generator was monitored when they
are in operation. Gas samples were collected from the stack of the thermal
oxidizer, landfill gas flare and landfill gas generator for laboratory analysis
for NO2, CO, SO2, Benzene and Vinyl chloride
and in-situ analysis for exhaust gas velocity at monthly interval and for
laboratory analysis for non-methane organic compounds and ammonia (for thermal
oxidizer only) at quarterly interval. The
operating conditions of the thermal oxidiser, landfill gas flare and landfill
gas generator were also monitored continuously.
The Limit
Levels for stack emission of the thermal oxidiser, landfill gas flare and
landfill gas generator are provided in Tables 2.8 – 2.10 below.
Table
2.8 Limit Levels for Stack Emission of the Thermal Oxidiser
Parameters |
Limit Level |
NO2 |
1.58 gs-1 |
CO |
0.53 gs-1 |
SO2 |
0.07 gs-1 |
Benzene |
3.01 x 10-2 gs-1 |
Vinyl chloride |
2.23 x 10-3 gs-1 |
Gas combustion temperature |
850oC (minimum) |
Exhaust gas exit temperature |
443K (minimum) (a) |
Exhaust gas velocity |
7.5 ms-1 (minimum) (a) |
Note: (a) Level under full load condition. |
Table
2.9 Limit Levels for Stack Emission of the Landfill Gas Flare
Parameters |
Limit Level |
NO2 |
0.97 gs-1 |
CO |
2.43 gs-1 |
SO2 |
0.22 gs-1 |
Benzene |
4.14 x 10-4 gs-1 |
Vinyl chloride |
2.60 x 10-4 gs-1 |
Gas combustion temperature |
815oC (minimum) |
Exhaust gas exit temperature |
923 K (minimum) (a) |
Exhaust gas velocity |
9.0 m s-1 (minimum) (a) |
Note: (a) Level under full load condition. |
Table 2.10
Limit Levels for Stack Emission of the Landfill Gas Generator
Parameters |
Limit Level |
NO2 |
1.91 gs-1 |
CO |
2.48 gs-1 |
SO2 |
0.528 gs-1 |
Benzene |
2.47 x 10-4 gs-1 |
Vinyl chloride |
1.88 x 10-5 gs-1 |
Gas combustion temperature |
450oC (minimum) |
Exhaust gas exit temperature |
723K (minimum) (a) |
Exhaust gas velocity |
30.0 ms-1 (minimum) (a) |
Note: (a) Level under full load condition. |
Gas samples were collected from the centroid of the stack with stainless
steel sampling probe, into inert sample containers (i.e. Canister and Tedlar
Bag) and transferred to ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No.
066) laboratory within 24 hours of collection for direct analysis on a gas
chromatography within 48 hours after collection. The flue gas velocity of
the gas stream at the exhaust of thermal oxidize was determined by S-Pitot tube
during the emission sampling.
The stack
emission monitoring programme and monitoring locations are summarised in Table
2.11 and illustrated in Figure 2.1, respectively.
Table 2.11
Thermal Oxidiser, Landfill Gas Flare and Landfill Gas Generator Stack Emission
Monitoring Details
Monitoring Location |
Parameter |
Frequency |
Monitoring Date |
Stack of Thermal Oxidiser |
Laboratory analysis for · NO2 · CO · SO2 · Benzene · Vinyl chloride In-situ analysis for · Exhaust gas velocity |
Monthly for the first 12 months of operation and thereafter at quarterly intervals |
6 May
2025 |
Laboratory analysis for · Non-methane organic compounds CO |
Quarterly for the 1st year of operation (b) |
6 May
2025 |
|
Laboratory analysis for · Ammonia · Gas combustion temperature · Exhaust temperature · Exhaust gas velocity (a) |
Quarterly |
6 May
2025 |
|
· Gas combustion temperature · Exhaust temperature · Exhaust gas velocity (a) |
Continuously |
1 – 31
May 2025 |
|
Stack of Landfill Gas Flare |
Laboratory analysis for · NO2 · CO · SO2 · Benzene · Vinyl chloride In-situ analysis for · Exhaust gas velocity |
Monthly for the first 12 months of operation and thereafter at quarterly intervals |
7 May
2025 |
Laboratory analysis for · Non-methane organic compounds CO |
Quarterly for the 1st year of operation (b) |
7 May
2025 |
Monitoring Location |
Parameter |
Frequency |
Monitoring Date |
Stack of Landfill Gas Flare |
· Gas combustion temperature · Exhaust temperature · Exhaust gas velocity (a) |
Continuously |
1 – 31
May 2025 |
Stack of Landfill Gas Generator |
Laboratory analysis for · NO2 · CO · SO2 · Benzene · Vinyl chloride In-situ analysis for · Exhaust gas velocity |
Monthly for the first 12 months of operation and thereafter at quarterly intervals |
7 May
2025 |
Laboratory analysis for · Non-methane organic compounds |
Quarterly for the 1st year of operation (b) |
7 May
2025 |
|
· Exhaust temperature · Exhaust gas velocity (a) |
Continuously |
1 – 31
May 2025 |
|
Notes: (a) The exhaust gas velocity is calculated based on the cross-section area of the stack and continuous monitored gas flow and combustion temperature data. (b) The monitoring results are being reviewed to determine if monitoring of this parameter can be terminated upon agreement by the EIAO Authority, IEC and Project Proponent. |
The
schedule for thermal oxidizer, landfill gas flare and landfill gas generator
stack emission monitoring during the reporting period is provided in Annex C.
The thermal
oxidizer, landfill gas flare and landfill gas generator stack emission
monitoring results and detailed continuous monitoring results are summarised in
Tables 2.12 - 2.14 and provided in Annex D7, respectively.
Table 2.12
Summary of Thermal Oxidiser Stack Emission Monitoring in the Reporting Period
Parameters |
Monitoring Results (Range in Bracket) |
Limit Level |
NO2 |
0.99 gs-1 |
1.58 gs-1 |
CO |
<0.01
gs-1 |
0.53 gs-1 |
SO2 |
<0.01
gs-1 |
0.07 gs-1 |
Benzene |
0.0011 gs-1 |
3.01 x 10-2 gs-1 |
Vinyl chloride |
<1.2
x 10-4 gs-1 |
2.23 x 10-3 gs-1 |
Non-Methane Organic Carbons |
0.004
gs-1 |
- |
Ammonia |
0.0664
gs-1 |
- (c) |
Gas combustion temperature |
899oC
(888oC – 907oC) |
850oC (minimum) |
Exhaust gas exit temperature |
1,191K
(1,152K – 1,213K) |
443K (minimum) (a) |
Exhaust gas velocity |
8.7 ms-1
(b) |
7.5 ms-1 (minimum) (a) |
Notes: (a) Level under full load condition. (b) The exhaust gas velocity was calculated based on the cross-section area of the stack and the gas flow and combustion temperature data measured during the stack emission monitoring. (c) The emission limit for ammonia is under review and will be supplemented in subsequent revision. |
Table 2.13
Summary of Landfill Gas Flare Stack Emission Monitoring in the Reporting Period
Parameters |
Monitoring Results (Range in Bracket) |
Limit Level |
NO2 |
<0.02
gs-1 |
0.97 gs-1 |
CO |
<0.01
gs-1 |
2.43 gs-1 |
SO2 |
<0.01
gs-1 |
0.22 gs-1 |
Benzene |
2.04 x
10-4 gs-1 |
4.14 x
10-4 gs-1 |
Vinyl chloride |
<9.3
x 10-5 gs-1 |
2.60 x
10-4 gs-1 |
Non-Methane Organic Carbons |
<0.002
gs-1 |
- |
Gas combustion temperature |
Flare 1: 894oC (871oC – 918oC) Flare
2: 910oC (886oC – 935oC) |
815oC
(minimum) |
Exhaust gas exit temperature |
Flare
1: 1,125K (1,101K – 1,153K) Flare 2: 1,144K (1,112K – 1,169K) |
923 K
(minimum) (a) |
Exhaust gas velocity |
9.0 ms-1
(b) |
9.0 m s-1 (minimum) (a) |
Notes: (a) Level under full load condition. (b) The exhaust gas velocity was calculated based on the cross-section area of the stack and the gas flow and combustion temperature data measured during the stack emission monitoring. |
Table 2.14
Summary of Landfill Gas Generator Stack Emission Monitoring in the Reporting
Period
Parameters |
Monitoring Results (Range in Bracket) |
Limit Level |
NO2 |
0.023
gs-1 |
1.91 gs-1 |
CO |
0.721
gs-1 |
2.48 gs-1 |
SO2 |
<0.001 gs-1 |
0.528
gs-1 |
Benzene |
1.17 x
10-4 gs-1 |
2.47 x
10-4 gs-1 |
Vinyl chloride |
7.2 x
10-6 gs-1 |
1.88 x
10-5 gs-1 |
Non-Methane Organic Carbons |
0.0038
gs-1 |
- |
Exhaust gas exit temperature |
ENGA:
869K (860K – 889K) ENGB: 875K (853K – 889K) |
723K
(minimum) (a) |
Exhaust gas velocity |
6.7 ms-1 (b) |
30.0 ms-1 (minimum) (a) |
Notes: (a) Level under full load condition. (b) The exhaust gas velocity was calculated based on the cross-section area of the stack and the gas flow and combustion temperature data measured during the stack emission monitoring. |
No
Action and Limit Level exceedance was recorded for thermal oxidizer, landfill
gas flare and landfill gas generator stack emission
monitoring in the reporting period. No action is thus required to be undertaken
in accordance with the Event and Action Plan presented in Annex D3.
According
to the updated EM&A Manual of the Project, ambient VOCs, ammonia and H2S
monitoring was carried out at the four designated locations along the site boundary (i.e. AM1, AM2, AM3
and AM4) during the operation/restoration phase, at quarterly interval. As
above-mentioned on Section 2.1.1.1, AM2 was temporarily relocated on 2 May 2025
due to the maintenance works at the DP3 drainage channel for the SENT Landfill.
The proposed temporary relocation of AM2 (named “AM2-TEMP”) has been agreed and
verified by the IEC and approved by EPD on 24 April 2025.
The Limit
Levels for ambient VOCs, ammonia and H2S monitoring is provided in Table
2.15 below.
Table 2.15
limit levels for ambient vocs, ammonia and h2s monitoring
Parameters |
Limit Level (µg m-³) |
Methane |
NA (a) |
Ammonia |
180 |
H2S |
42 |
Dichlorodifluoro-methane |
NA (a) |
Vinyl Chloride |
26 |
Methanol |
2,660 |
Ethanol |
19,200 |
Dimethylsulphide |
8 |
Carbon Disulphide |
150 |
Methylene Chloride |
3,530 |
Chloroform |
99 |
Methyl propionate |
353 |
Butan-2-ol |
667 |
1.1.1-Trichloroethane |
5,550 |
1.2-Dichloroethane |
210 |
Benzene |
33 |
Carbon Tetrachloride |
64 |
Dipropyl ether |
NA (a) |
Heptane |
2,746 |
Trichloroethylene |
5,500 |
Ethyl propionate |
29 |
Methyl butanoate |
30 |
Methanethiol |
10 |
Toluene |
1,244 |
Ethyl butanoate |
71 |
Propyl benzene |
19 |
Octane |
7,942 |
Propyl propionate |
276 |
1.2-Dibromoethane (EDB) |
39 |
Butyl acetate |
7,240 |
Tetrachloroethylene |
1,380 |
Ethyl benzene |
738 |
Nonane |
11,540 |
Ethanethiol |
13 |
Decanes |
3,608 |
Limonene |
212 |
Butyl benzene |
47 |
Undecane |
5,562 |
Butanethiol |
4 |
Terpenes |
NA (a) |
Xylenes |
534 |
Dichlorobenzene |
120 |
Note: (a) No relevant WHO/USEPA/CARB’s ambient criteria, odour thresholds and WEL available. |
Ambient air
samples were drawn into the pre-cleaned and vacuum canister directly when the
valve of the flow controller (with preset flow rate) was opened. After
sampling, the valve will be closed manually and the canister with VOCs gas
samples were transported for laboratory analysis.
Pre-cleaned
Tedlar bag was placed in the vacuum chamber. Ambient air was collected in
the Tedlar bag under the vacuum condition when the pump is switched on.
The Tedlar bag was filled up to 90% of total capacity to avoid leakage and bag
deformation. After sampling, pump is switched off and the valve of Tedlar
bag was closed manually. The air samples were transported back to
laboratory for analysis.
Calibrated
personal air pump was used to pump the air through a sulfuric acid-treated
silica gel sorbent tube. Gaseous ammonia in air was then trapped in the
sorbent tube. The tube was transported back to laboratory for analysis.
H2S
in air is collected in mid-get impingers by aspirating a measured
volume of air through an alkaline suspension of cadmium hydroxide (as the
absorbing solution). The sulphide is precipitated as cadmium sulphide to
prevent air oxidation of the sulphide. Arabinogalactan is added to the
cadmium hydroxide slurry prior to sampling to minimize photo-decomposition of
the precipitated cadmium sulphide. The solution is transported back to
laboratory for analysis.
All air
samples collected for laboratory analysis were transported to ALS Technichem
(HK) Pty Ltd. (HOKLAS Registration No. 066) laboratory within 24 hours and
analysed within 48 hours.
The ambient
VOCs, ammonia and H2S monitoring programme and monitoring locations
are summarised in Table 2.16 and illustrated in Figure 2.1, respectively.
Table 2.16
ambient vocs, ammonia and h2s monitoring details
Monitoring Station |
Location |
Parameter |
Frequency |
Monitoring Date |
AM1 |
SENTX Site
Boundary (North) |
· Methane · Ammonia · A
suite of VOCs (a) · H2S |
Quarterly |
2 May
2025 |
AM2-TEMP |
SENTX
Site Boundary (West, opposite DP3) |
|||
AM3 |
SENTX Site Boundary (West, near RC15) |
|||
AM4 |
SENTX Site Boundary (West, near EPD building) |
|||
Note: (a) A suite of VOCs includes: |
||||
|
· Butyl benzene · Xylenes · Decanes · Undecane · Limonene · Terpenes · Ethanol · Butan-2-ol · Dimethylsulphide · Methyl propionate · Ethyl propionate · Propyl propionate · Butyl acetate
|
· Dichlorobenzene · Methyl butanoate · Dipropyl ether · Methanethiol · Ethanethiol · Butanethiol · Methanol · Heptanes · Octanes · Nonanes · Dichlorodifluoro-methane
|
The
schedule for ambient VOCs, ammonia and H2S monitoring during the
reporting period is provided in Annex
C.
The ambient
VOCs, ammonia and H2S monitoring results are summarized in Tables
2.17 and provided in Annex
D8.
Table 2.17
summary of ambient vocs, ammonia and h2s monitoring results in the reporting
period
Parameters |
Limit Level (µg m-³) |
Monitoring Results (µg m-³) |
|||
AM1 |
AM2-TEMP |
AM3 |
AM4 |
||
Ammonia |
180 |
13 |
<10 |
<10 |
<10 |
H2S |
42 |
<15 |
<15 |
<15 |
<15 |
Methane |
NA (a) |
0.0002
%(v/v) |
0.00021 %(v/v) |
0.0002%(v/v) |
0.00021 %(v/v) |
1.1.1-Trichloroethane |
5,550 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
1.2-Dibromoethane (EDB) |
39 |
<1.0 |
<1.0 |
<1.0 |
<1.0 |
1.2-Dichloroethane |
210 |
0.9 |
1 |
0.8 |
0.6 |
Benzene |
33 |
0.8 |
0.8 |
0.7 |
0.6 |
Butan-2-ol |
667 |
<0.6 |
<0.6 |
<0.6 |
<0.6 |
Butanethiol |
4 |
<1.2 |
<1.2 |
<1.2 |
<1.2 |
Carbon Disulphide |
150 |
0.5 |
0.9 |
0.8 |
0.5 |
Carbon Tetrachloride |
64 |
0.6 |
0.6 |
0.6 |
<0.6 |
Chloroform |
99 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Decanes |
3,608 |
<0.7 |
<0.7 |
<0.7 |
<0.7 |
Dichlorobenzene |
120 |
<1.0 |
<1.0 |
<1.0 |
<1.0 |
Dichlorodifluoro-methane |
NA (a) |
1.5 |
1.4 |
1.4 |
1.3 |
Dimethylsulphide |
8 |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
Dipropyl ether |
NA (a) |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Limonene |
212 |
<0.4 |
0.5 |
0.5 |
<0.4 |
Ethanethiol |
13 |
<0.6 |
<0.6 |
<0.6 |
<0.6 |
Ethanol |
19,200 |
4.6 |
4.7 |
6.8 |
8.4 |
Ethyl butanoate |
71 |
<1.0 |
<1.0 |
<1.0 |
<1.0 |
Ethyl propionate |
29 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Ethyl benzene |
738 |
0.7 |
1 |
0.7 |
0.7 |
Heptane |
2,746 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Methanethiol |
10 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
Methanol |
2,660 |
11 |
10.4 |
23 |
10.5 |
Methyl butanoate |
30 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Methyl propionate |
353 |
<0.7 |
<0.7 |
<0.7 |
<0.7 |
Methylene Chloride |
3,530 |
6.9 |
7.2 |
5.6 |
5.7 |
Butyl acetate |
76 |
<1.0 |
<1.0 |
<1.0 |
<1.0 |
Butyl benzene |
47 |
<1.0 |
<1.0 |
<1.0 |
<1.0 |
Nonane |
11,540 |
<0.9 |
<0.9 |
<0.9 |
<0.9 |
Propyl benzene |
19 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Octane |
7,942 |
<0.9 |
<0.9 |
<0.9 |
<0.9 |
Propyl propionate |
276 |
<1.0 |
<1.0 |
<1.0 |
<1.0 |
Terpenes |
NA (a) |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Tetrachloroethylene |
1,380 |
<0.7 |
<0.7 |
<0.7 |
<0.7 |
Toluene |
1,244 |
1.9 |
2.6 |
1.9 |
2.5 |
Trichloroethylene |
5,500 |
<1.1 |
<1.1 |
<1.1 |
<1.1 |
Undecane |
5,562 |
<1.2 |
<1.2 |
<1.2 |
<1.2 |
Vinyl Chloride |
26 |
<0.3 |
<0.3 |
<0.3 |
<0.3 |
Xylenes |
534 |
0.6 |
2.4 |
0.8 |
0.9 |
Note: (a) No relevant WHO/USEPA/CARB’s ambient criteria and WEL available. |
All ambient VOCs, ammonia and H2S monitoring results were
below the Limit Levels in the reporting period. No action is thus
required to be undertaken in accordance with the Event and Action Plan
presented in Annex D3.
According
to the updated EM&A Manual of the Project, noise levels at noise monitoring
location NM1 and NM2 should be monitored during first 3 years of operation and
during the next 3 years of operation until the completion of the Restoration
phase, respectively. Impact noise monitoring was conducted weekly at the
monitoring location (i.e. at NM1 before 20 November 2024; and at NM2 from 20
November 2024) to obtain one set of 30-minute measurement between 07:00 and
19:00 hours on normal weekdays.
The Action
and Limit Levels for operational noise of the Project are provided in Table
2.18 below.
Table 2.18
Action and Limit Levels for Operational Noise
Time Period |
Action Level (a) |
Limit Level (b) |
07:00 – 19:00 hrs on all days
|
When one documented complaint is received from any one of the noise sensitive receivers (NSRs) or 75 dB(A) recorded at the monitoring station |
65 dB(A) at NSRs (c) |
19:00 – 23:00 hrs on all days
|
65 dB(A) at NSRs (c) |
|
23:00 – 07:00 hrs on all days |
55 dB(A) at NSRs (c) |
|
Notes: (a) 75dB(A) along and at about 100m from the SENTX site boundary was set as the Action Level. (b) Limits specified in the GW-TM and IND-TM for construction and operational noise, respectively. (c) Limit Level only apply to operational noise without road traffic and construction activities noise. |
Noise monitoring was performed by ALS Technichem (HK) Pty Ltd. (HOKLAS
Registration No. 066) using sound level meter at the designated monitoring
station NM1 (see Figure 2.1)
in accordance with the requirements stipulated in the updated
EM&A Manual. Acoustic calibrator was deployed to check the sound
level meter at a known sound pressure level. Details of the deployed equipment
are provided in Table 2.19. Copies of the calibration certificates for
the equipment are presented in Annex
E1.
Table 2.19
Noise Monitoring Details
Monitoring Station |
Location |
Parameter |
Frequency and Duration |
Monitoring Dates |
Equipment |
NM2 |
SENTX Site Boundary (East) |
Leq (30 min) measurement between 07:00 and 19:00 hours on normal weekdays (Monday to Saturday) |
Once per week for 30 mins during operation of the Project |
6, 15, 21, 27 May 2025 |
Sound Level Meter: Rion NL-52 (S/N: 00331806)
Acoustic Calibrator: CAL200 (S/N: 11333)
|
The
schedule for noise monitoring during the reporting period is provided in Annex C.
A total of
4 impact noise monitoring events were scheduled during the reporting
period. Results for noise monitoring are summarised in Table 2.20.
The monitoring results and the graphical presentation of the data are provided
in Annex E2.
Table 2.20
Summary of Operation Noise Monitoring Results in the Reporting Period
|
Measured Noise Level Leq (30 min), dB(A) |
||
Monitoring Station |
Average |
Range |
Action and Limit Level |
NM2 |
44.6 |
42.1 –
48.7 |
75 |
Major noise sources identified during the noise monitoring included
noise from aircrafts.
No Action and Limit Levels exceedance was recorded for operation noise
monitoring in the reporting period. No action is thus required to be
undertaken in accordance with the Event and Action Plan presented in Annex E3.
According
to the updated EM&A Manual of the Project, impact surface water quality
monitoring was carried out at the three designated surface water discharge
points (i.e. DP3, DP4 and DP6) at monthly intervals during operation/
restoration phase to ensure that the SENTX will not cause adverse water quality
impact.
The
parameters as listed in Table 2.22 were determined by ALS Technichem
(HK) Pty Ltd. (HOKLAS Registration No. 066).
The Limit
Levels of the surface water quality impact monitoring are provided in Table
2.21.
Table 2.21
Limit Levels for Surface Water Quality
Parameters |
Limit Level |
DP3 |
|
Ammoniacal-nitrogen |
> 0.5 mg/L |
COD |
> 80 mg/L |
SS |
> 30 mg/L |
DP4 & DP6 |
|
Ammoniacal-nitrogen |
> 7.1 mg/L |
COD |
> 30 mg/L |
SS |
> 20 mg/L |
Note: The limit levels specified for other parameters in Table 10a of the Technical Memorandum Standards for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters shall also be followed. |
The locations of the monitoring stations for the Project are shown in Figure 2.1. All in
situ monitoring instruments were checked, calibrated and certified by a
laboratory accredited under HOKLAS or other international accreditation scheme
before use, and subsequently re-calibrated at 3 monthly intervals throughout
all stages of the surface water quality monitoring programme. Calibration
for a DO meter was carried out before measurement according to the instruction
manual of the equipment model. Details of the equipment used in the impact
surface water quality monitoring works are provided in Table 2.22.
Copies of the calibration certificates for the equipment are presented in Annex F1.
Table 2.22
Impact Surface Water Quality Monitoring Details
Monitoring Station |
Location |
Frequency |
Monitoring Dates |
Parameter |
Equipment |
|
DP3 |
Surface water discharge point DP3 |
Monthly |
7 May 2025 |
·
pH
·
Electrical
conductivity (EC) ·
DO
·
SS
·
COD ·
BOD5
·
TOC
·
Ammoniacal–nitrogen
·
Nitrate-nitrogen ·
Nitrite–nitrogen ·
TKN ·
TN ·
Phosphate ·
Sulphate ·
Sulphide ·
Carbonate ·
Oil
& Grease |
·
Bicarbonate ·
Chloride
·
Sodium
·
Potassium
·
Calcium ·
Magnesium ·
Nickel ·
Manganese ·
Chromium
·
Cadmium
·
Copper ·
Lead ·
Iron ·
Zinc ·
Mercury
·
Boron |
Horiba U-52G
(S/N: NVAE08GT) |
DP4 |
Surface water discharge point DP4 |
|||||
DP6 |
Surface water discharge point DP6 |
The
schedule for surface water quality monitoring during the reporting period is
provided in Annex C.
One
monitoring event for impact surface water quality monitoring was scheduled at
all designated monitoring stations during the reporting period. However,
sampling could not be carried out on 7 May 2025 due to insufficient flow.
Details of impact water quality monitoring event are provided in Annex F2.
No
action is thus required to be undertaken in accordance with the event and
action plan presented in Annex
F3.
According
to the updated EM&A Manual, continuous monitoring of leachate level and
monthly monitoring of effluent quality were carried out during the operation/
restoration phase.
Reduction
of effluent monitoring frequency (dry season) (from daily to monthly) was
approved by EPD on 22 March 2022. Monthly effluent quality monitoring
(dry season) shall be conducted from 23 March 2022. The reduction of
effluent monitoring frequency (wet season) (from daily to monthly) was approved
by EPD on 2 August 2022. Monthly effluent quality monitoring (wet season)
shall be conducted from 3 August 2022.
Temperature,
pH and volume of the effluent discharged from the leachate treatment plant were
measured in-situ whereas the parameters as listed in Table 2.24 were
determined by ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066).
The Limit
Levels of the leachate monitoring are provided in Table 2.23.
Table 2.23
Limit Levels for Leachate Levels and Effluent Quality
Parameters |
Limit Level |
Leachate Levels |
|
Leachate levels above the basal liner |
1 m above the primary liner of the leachate containment system |
Effluent Quality |
|
Temperature |
> 43 °C |
pH Value |
6 – 10 |
Volume Discharged |
>2,000 m³ |
Suspended Solids (SS) |
> 800 mg/L |
Phosphate |
> 25 mg/L |
Sulphate |
> 800 mg/L |
Total Inorganic Nitrogen (a) |
> 100 mg/L |
Biochemical Oxygen Demand (BOD) |
> 800 mg/L |
Chemical Oxygen Demand (COD) |
> 2,000 mg/L |
Oil & Grease |
> 20 mg/L |
Boron |
> 7,000 µg/L |
Iron |
> 5 mg/L |
Cadmium |
> 1 µg/L |
Chromium |
> 300 µg/L |
Copper |
> 1,000 µg/L |
Nickel |
> 700 µg/L |
Zinc |
> 700 µg/L |
Note: (a) Total Inorganic Nitrogen include Ammoniacal-nitrogen, Nitrite-nitrogen and Nitrate-nitrogen. |
All in situ monitoring instruments were checked, calibrated and
certified by a laboratory accredited under HOKLAS or other international
accreditation scheme before use, and subsequently re-calibrated at 3 monthly
intervals throughout all stages of the leachate quality monitoring programme.
Details of the equipment used are provided in Table 2.24. Copies of the
calibration certificates for the equipment are presented in Annex F4.
Table 2.24
Leachate Levels and Effluent Quality Monitoring Details
Location |
Frequency |
Parameter |
Monitoring Dates |
Equipment |
Leachate levels above the basal liner
|
Continuous |
Leachate Levels |
1 – 31
May 2025 |
Pairs of
pressure transducers |
Effluent discharged from LTP |
Daily for the first 3 months upon full operation of the LTP at wet season (Apr to Sep) and dry season (Oct to Mar), respectively and reduce to monthly thereafter subject to the monitoring results of the first 3 months for each season and agreement with the EIAO Authority, IEC and IC. (a) |
On-site Measurements: · Volume · pH · Temperature Laboratory analysis: · Suspended Solids · COD · BOD5 · TOC · Ammoniacal–nitrogen
· Nitrate-nitrogen · Nitrite–nitrogen · Total Nitrogen · Sulphate · Phosphate · Oil & Grease · Alkalinity · Chloride · Calcium · Potassium · Magnesium · Iron · Zinc · Copper · Chromium · Nickel · Cadmium · Boron
|
8 May
2025 |
Lutron
PH-208 (S/N: TF31039) |
Note: (a) Reduction of monitoring frequency will be subject to the monitoring results to demonstrate environmentally acceptable performance. |
The
schedule for leachate monitoring during the reporting period is provided in Annex C.
The
leachate levels and effluent quality monitoring results are summarised in Table
2.25 and Table 2.26, respectively. The detailed monitoring
results are provided in Annex
F5 and Annex
F6, respectively.
Table 2.25
Summary of Leachate Levels in the Reporting Period
Monitoring Location |
Average Leachate Head Levels (cm) (Range in Bracket) |
Limit Level (cm) |
Pump Station No. 1X (Cell 1X) |
||
Meter
No. X-1 |
109 (93
– 119) |
>178 |
Meter
No. X-2 |
102 (88
– 119) |
|
Average |
105 (93
– 119) |
|
Pump
Station No. 2X (Cell 2X) |
||
Meter
No. X-3 |
106
(106 – 106) |
>180 |
Meter
No. X-4 |
118
(102 – 119) |
|
Average |
112
(104 – 113) |
|
Pump
Station No. 3X (Cell 3X) |
||
Meter
No. X-5 |
80 (70
– 95) |
> 175 |
Meter
No. X-6 |
106 (93
– 119) |
|
Average |
93 (82
– 107) |
|
Pump
Station No. 4X (Cell 4X) |
||
Meter
No. X-7 |
111
(103 – 120) |
> 186 |
Meter
No. X-8 |
112
(102 – 120) |
|
Average |
111
(103 – 120) |
Table 2.26
Summary of Effluent Quality Monitoring Results in the Reporting Period
Parameters |
Monitoring Results |
Limit Level |
|
Effluent Discharged from LTP |
|
||
Temperature |
°C |
28.5 |
> 43 °C |
pH Value |
pH unit |
8.4 |
6 – 10 |
Volume Discharged |
m³ |
1,132 |
>2,000 m³ |
Suspended Solids (SS) |
mg/L |
167 |
> 800 mg/L |
Phosphate |
mg/L |
2.54 |
> 25 mg/L |
Sulphate |
mg/L |
221 |
> 800 mg/L |
Total Inorganic Nitrogen (a) |
mg/L |
49.27 |
> 100 mg/L |
BOD |
mg/L |
14 |
> 800 mg/L |
COD |
mg/L |
872 |
> 2,000 mg/L |
Oil & Grease |
mg/L |
<5 |
> 20 mg/L |
Boron |
µg/L |
4760 |
> 7,000 µg/L |
Iron |
mg/L |
1.32 |
> 5 mg/L |
Cadmium |
µg/L |
<1.0 |
> 1 µg/L |
Chromium |
µg/L |
94 |
> 300 µg/L |
Copper |
µg/L |
<10 |
> 1,000 µg/L |
Nickel |
µg/L |
86 |
> 700 µg/L |
Zinc |
µg/L |
45 |
> 700 µg/L |
Note: (a) Total Inorganic Nitrogen include Ammoniacal-nitrogen, Nitrite-nitrogen and Nitrate-nitrogen. |
All leachate levels and effluent quality monitoring results were below
the Limit Levels in the reporting period. No action is thus required to be
undertaken in accordance with the Event and Action Plan presented in Annex F3.
According
to the updated EM&A Manual of the Project with incorporation of the
proposed updates under the Amendment Summary approved by EPD on 15 June 2020,
groundwater monitoring was carried out at 14 perimeter groundwater monitoring
wells (including 3 up-gradient wells and 11 down-gradient wells) (i.e. MWX-1 to
MWX-14) to monitor the groundwater quality and level of the perimeter
groundwater monitoring wells at monthly interval.
The Limit
Levels for groundwater quality is provided in Table 2.27 below.
Table 2.27
Limit Levels for Groundwater Quality
Location
|
Limit Levels |
|
Ammoniacal-nitrogen (mg L-1) |
COD (mg L-1) |
|
MWX-1 |
5.00 |
30 |
MWX-2 |
5.00 |
30 |
MWX-3 |
5.00 |
30 |
MWX-4 |
7.63 |
36 |
MWX-5 |
5.00 |
30 |
MWX-6 |
5.00 |
46 |
MWX-7 |
6.55 |
36 |
MWX-8 |
15.85 |
50 |
MWX-9 |
7.30 |
71 |
MWX-10 |
5.00 |
30 |
MWX-11 |
5.00 |
30 |
MWX-12 |
5.00 |
30 |
MWX-13 |
5.00 |
30 |
MWX-14 |
5.00 |
30 |
A bladder pump with Teflon sampling tube and adjustable discharge rates
was used for purging and taking of groundwater sample from the monitoring
wells. Filtered groundwater samples were collected by connecting a disposable
in-line filter system to the tubing of the sampling pump, prior to storage and
analysis by ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066). A
portable dip meter with 5mm accuracy was used for measurement of groundwater
level at each well. The dip meter has an audio indicator of the water
level and was checked before use.
The
measurements of pH and electrical conductivity (EC) were undertaken in situ.
In situ monitoring instruments in compliance with the specifications
listed under Section 4.3.2 of the updated EM&A Manual were used to
undertake the groundwater quality monitoring for the Project. Details of
the equipment used and the monitoring locations are summarised in Table 2.28
and illustrated in Figure
2.1, respectively. Copies of the calibration certificates
for the equipment are presented in Annex F7.
Table 2.28
groundwater monitoring details
Location |
Frequency |
Parameter |
Monitoring Dates |
Equipment |
|
All groundwater monitoring wells (MWX-1 to MWX-14) |
Monthly |
· Water level · pH · EC · COD · BOD5 · TOC · Ammoniacal–nitrogen · Nitrate-nitrogen · Nitrite–nitrogen · TKN · TN · Sulphate · Sulphide · Carbonate · Bicarbonate · Phosphate |
· Chloride · Sodium · Potassium · Calcium · Magnesium · Nickel · Manganese · Chromium · Cadmium · Copper · Lead · Iron · Zinc · Mercury · Boron |
7 May
2025 |
Horiba U-52G (S/N: NVAE08GT) |
The
schedule for groundwater quality monitoring during the reporting period is
provided in Annex C.
The
groundwater quality monitoring results and detailed monitoring results are
summarised in Table 2.29 and provided in Annex F8, respectively.
Table 2.29
Summary of Groundwater Monitoring Results in the Reporting Period
Location
|
Ammoniacal-nitrogen (mg L-1) |
COD (mg L-1) |
||
Monitoring Results |
Limit Levels |
Monitoring Results |
Limit Levels |
|
MWX-1 |
0.46 |
5.00 |
5 |
30 |
MWX-2 |
0.14 |
5.00 |
3 |
30 |
MWX-3 |
1.02 |
5.00 |
15 |
30 |
MWX-4 |
1.31 |
7.63 |
14 |
36 |
MWX-5 |
2.88 |
5.00 |
32 |
30 |
MWX-6 |
3.58 |
5.00 |
33 |
46 |
MWX-7 |
1.12 |
6.55 |
19 |
36 |
MWX-8 |
15.8 |
15.85 |
36 |
50 |
MWX-9 |
0.25 |
7.30 |
20 |
71 |
MWX-10 |
N/A
(a) |
5.00 |
N/A
(a) |
30 |
MWX-11 |
0.05 |
5.00 |
<2 |
30 |
MWX-12 |
<0.01 |
5.00 |
<2 |
30 |
MWX-13 |
<0.01 |
5.00 |
<2 |
30 |
MWX-14 |
<0.01 |
5.00 |
<2 |
30 |
Note: Monitoring well MWX-10 is under maintenance. (a) |
Limit Level exceedances were recorded for groundwater monitoring in the
reporting period and actions in accordance with the Event and Action Plan
presented in Annex F3 were
undertaken. The groundwater (COD) exceedance at MWX-5 on 7 May 2025 is under
investigation.
The Contractor was reminded to implement all relevant mitigation
measures for the construction and operation works and maintain good site
practice. The ET will keep track on the monitoring data and ensure Contractor’s
compliance of the environmental requirements.
According
to the updated EM&A Manual of the Project, landfill gas monitoring was
carried out at the perimeter of the waste boundary (monitoring wells), area
between the SENTX Site boundary and the waste boundary (surface emission),
occupied on-site building, service voids, utilities pit and manholes in the
vicinity of the SENTX (build-up of landfill gas) during the
operation/restoration phase.
The Limit
Levels for landfill gas monitoring is provided in Table 2.30 below.
Table 2.30
Limit Levels for Landfill Gas Constituents
Parameters |
Monitoring Location |
Limit Level (% (v/v)) |
|
Perimeter Landfill Gas Monitoring Wells (a) |
|||
Methane & Carbon Dioxide |
|
Methane |
Carbon Dioxide |
LFG1 |
1.0 |
3.2 |
|
LFG2 |
1.0 |
4.3 |
|
LFG3 |
1.0 |
6.3 |
|
LFG4 |
1.0 |
7.0 |
|
LFG5 |
1.0 |
3.4 |
|
LFG6 |
1.0 |
9.1 |
|
LFG7 |
1.0 |
1.5 |
|
LFG8 |
12.6 |
2.4 |
|
LFG9 |
2.5 |
1.7 |
|
LFG10 |
3.5 |
1.6 |
|
LFG11 |
3.0 |
2.0 |
|
LFG12 |
13.2 |
1.5 |
|
LFG13 |
22.5 |
2.7 |
|
LFG14 |
5.2 |
1.8 |
|
LFG15 |
18.2 |
2.0 |
|
LFG16 |
1.0 |
2.0 |
|
LFG17 |
17.8 |
2.4 |
|
LFG18 |
2.3 |
2.1 |
|
LFG19 |
6.3 |
3.1 |
|
LFG20 |
1.0 |
4.6 |
|
LFG21 |
1.0 |
4.8 |
|
LFG22 |
1.0 |
4.0 |
|
LFG23 |
1.0 |
10.3 |
|
LFG24 |
1.0 |
4.7 |
|
GP1 |
1.0 |
10.6 |
|
GP2 (shallow) |
1.0 |
11.4 |
|
GP2 (deep) |
1.0 |
10.4 |
|
GP3 (shallow) |
1.0 |
6.9 |
|
GP3 (deep) |
1.0 |
5.6 |
|
GP4 (shallow) |
1.0 |
11.6 |
|
GP4 (deep) |
1.0 |
7.7 |
|
GP5 (shallow) |
1.0 |
10.8 |
|
GP5 (deep) |
1.0 |
7.5 |
|
GP6 |
1.0 |
8.4 |
|
GP7 |
1.0 |
4.5 |
|
GP12 |
1.0 |
2.3 |
|
GP15 |
1.0 |
2.2 |
|
P7 |
1.0 |
2.5 |
|
P8 |
1.0 |
1.7 |
|
P9 |
1.0 |
2.7 |
|
Service Voids, Utilities Pits and Manholes |
|||
Methane (or flammable gas) |
Service voids, utilities pits and manholes |
1% by volume |
|
Permanent Gas Monitoring System |
|||
Methane (or flammable gas) |
Permanent Gas Monitoring System |
1% by volume (20% LEL) |
|
Area Between the SENTX Site Boundary and Waste Boundary (Surface Emission) |
|||
Flammable gas |
Area between SENTX site boundary and waste boundary |
30 ppm |
|
Note: (a) Limit Levels established based on the pre-operation phase baseline and additional landfill gas monitoring results in the Pre-operation Baseline Monitoring Report. |
Gas analysers in compliance with the specifications listed under Section
5.4.1 of the updated EM&A Manual were used to monitor the gas parameters at
the landfill gas monitoring wells, service voids, utilities pits and
manholes. The gas analyser was calibrated by a laboratory accredited
under HOKLAS at yearly intervals and checked before use to ensure the validity
and accuracy of the results. A portable dip meter was used to monitor the water
level in the monitoring wells.
Permanent
gas monitoring systems with pre-set alarm levels for methane at 20% lower
explosive limit (LEL, equivalent to 1% methane gas (v/v)) were installed and
operated in all occupied on-site buildings at SENTX. A central control
panel is equipped to alert site personnel when the gas concentration at any
detector reaches the alarm level.
The
equipment used in the landfill gas monitoring programme is summarised in Table
2.31. The landfill gas monitoring locations for perimeter
landfill gas monitoring wells, flammable gas surface emission survey route and
service voids, utilities and manholes along the Site boundary are illustrated
in Figures 2.3-2.4 and Annex G1, respectively.
Copies of the calibration certificates for the equipment are presented in Annex G2. The
flammable gas surface emission survey route has been reviewed and updated
against the latest construction/ operation programme and approved by EPD on 17
June 2024.
Table 2.31
Landfill Gas Monitoring Details
Monitoring Location |
Frequency |
Parameter |
Monitoring Dates |
Equipment |
Perimeter landfill gas monitoring wells (LFG1 to LFG24, P7 to P9, GP1 to GP7, GP12 and GP15)
|
Monthly |
· Methane · Carbon dioxide · Oxygen · Atmospheric pressure |
8 May
2025 |
GA5000
(S/N: G510727) |
Service voids, utilities and manholes along the Site boundary and within the SENTX Site (UU1 to UU28) |
Monthly |
· Methane · Carbon dioxide · Oxygen |
7 May
2025 |
GA5000
(S/N: G510727) |
Permanent gas monitoring system in all occupied on-site buildings |
Continuous |
Methane (or flammable gas) by permanent gas monitoring system |
1 – 31
May 2025 |
Permanent
gas monitoring system |
Areas between the SENTX Site boundary and the waste boundary and location of vegetation stress |
Quarterly |
Flammable gas emitted from the ground surface |
6 May
2025 |
GMI
Leak Surveyor (S/N: 554846) |
Bulk gas sampling at least 2 of the perimeters LFG monitoring wells |
Quarterly |
Methane Carbon dioxide Oxygen Nitrogen Carbon monoxide Other flammable gas |
8 May
2025 |
Gas
sampling pump and Tedlar bags |
The
schedule for landfill gas monitoring during the reporting period is provided in
Annex C.
The
landfill gas monitoring results are summarised and provided in Tables 2.32 -
2.35 and Annex
G3, respectively.
Table 2.32 Summary of Landfill Gas Monitoring
Results at Perimeter LFG Monitoring Wells in the Reporting Period
Location
|
Methane (% (v/v)) |
Carbon Dioxide (% (v/v)) |
||
Monitoring Results |
Limit Levels (a) |
Monitoring Results |
Limit Levels (a) |
|
LFG1 |
0.0 |
1.0 |
1.2 |
3.2 |
LFG2 |
0.0 |
1.0 |
0.8 |
4.3 |
LFG3 |
0.0 |
1.0 |
2.8 |
6.3 |
LFG4 |
0.0 |
1.0 |
0.1 |
7.0 |
LFG5 |
0.0 |
1.0 |
0.6 |
3.4 |
LFG6 |
0.0 |
1.0 |
0.1 |
9.1 |
LFG7 |
0.0 |
1.0 |
0.1 |
1.5 |
LFG8 |
0.0 |
12.6 |
0.1 |
2.4 |
LFG9 |
0.0 |
2.5 |
0.1 |
1.7 |
LFG10 |
0.0 |
3.5 |
0.1 |
1.6 |
LFG11 |
0.0 |
3.0 |
0.1 |
2.0 |
LFG12 |
0.0 |
13.2 |
0.2 |
1.5 |
LFG13 |
9.1 |
22.5 |
0.3 |
2.7 |
LFG14 |
0.0 |
5.2 |
0.1 |
1.8 |
LFG15 |
0.0 |
18.2 |
0.1 |
2.0 |
LFG16 |
0.0 |
1.0 |
0.1 |
2.0 |
LFG17 |
0.0 |
17.8 |
0.1 |
2.4 |
LFG18 |
0.0 |
2.3 |
0.8 |
2.1 |
LFG19 |
0.0 |
6.3 |
0.2 |
3.1 |
LFG20 |
0.0 |
1.0 |
1.5 |
4.6 |
LFG21 |
0.0 |
1.0 |
0.2 |
4.8 |
LFG22 |
0.0 |
1.0 |
0.1 |
4.0 |
LFG23 |
0.0 |
1.0 |
0.1 |
10.3 |
LFG24 |
0.0 |
1.0 |
0.1 |
4.7 |
GP1 |
0.0 |
1.0 |
6.7 |
10.6 |
GP2 (shallow) |
0.0 |
1.0 |
0.2 |
11.4 |
GP2 (deep) |
0.0 |
1.0 |
0.3 |
10.4 |
GP3 (shallow) |
0.0 |
1.0 |
0.2 |
6.9 |
GP3 (deep) |
0.0 |
1.0 |
0.1 |
5.6 |
GP4 (shallow) |
0.0 |
1.0 |
1.2 |
11.6 |
GP4 (deep) |
0.0 |
1.0 |
0.8 |
7.7 |
GP5 (shallow) |
0.0 |
1.0 |
0.1 |
10.8 |
GP5 (deep) |
0.0 |
1.0 |
0.3 |
7.5 |
GP6 |
0.0 |
1.0 |
2.4 |
8.4 |
GP7 |
0.0 |
1.0 |
1.9 |
4.5 |
GP12 |
0.0 |
1.0 |
0.8 |
2.3 |
GP15 |
0.0 |
1.0 |
0.2 |
2.2 |
P7 |
0.0 |
1.0 |
0.2 |
2.5 |
P8 |
0.0 |
1.0 |
0.4 |
1.7 |
P9 |
0.0 |
1.0 |
1.2 |
2.7 |
Notes: (a) Limit Levels established based on the pre-operation phase baseline and additional landfill gas monitoring results in the Pre-operation Baseline Monitoring Report. |
Table 2.33 Summary of Landfill Gas Monitoring
Results at Service Voids, Utilities Pits and Manholes in the Reporting Period
Location
|
Methane (% (v/v)) |
|
Monitoring Results |
Limit Levels |
|
UU01 |
0.0 |
1.0 |
UU02 |
0.0 |
1.0 |
UU03 |
Voided due to latest site programme and on-going operation work |
1.0 |
UU04 |
0.0 |
1.0 |
UU05 |
0.0 |
1.0 |
UU06 |
0.0 |
1.0 |
UU07 |
0.0 |
1.0 |
UU08 |
0.0 |
1.0 |
UU09 |
0.0 |
1.0 |
UU10 |
0.0 |
1.0 |
UU11 |
0.0 |
1.0 |
UU12 |
Voided
due to latest site programme and on-going operation work |
1.0 |
UU13 |
0.0 |
1.0 |
UU14 |
0.0 |
1.0 |
UU15 |
0.0 |
1.0 |
UU16 |
0.0 |
1.0 |
UU17 |
Voided
due to latest site programme and on-going operation work |
1.0 |
UU18 |
Voided
due to latest site programme and on-going operation work |
1.0 |
UU19 |
Voided
due to latest site programme and on-going operation work |
1.0 |
UU20 |
0.0 |
1.0 |
UU21 |
0.0 |
1.0 |
UU22 |
0.0 |
1.0 |
UU23 |
0.0 |
1.0 |
UU24 |
0.0 |
1.0 |
UU25 |
0.0 |
1.0 |
UU26 |
0.0 |
1.0 |
UU27 |
0.0 |
1.0 |
UU28 |
0.0 |
1.0 |
Table 2.34 Summary of Landfill Gas bulk
sampling Monitoring Results in the reporting period
Parameters |
Limit Level (LFG4) (a) |
LFG4 |
Limit Level (LFG6) (a) |
LFG6 |
Methane (% (v/v)) |
1.0 |
<0.020 |
1.0 |
<0.020 |
Carbon Dioxide (% (v/v)) |
7.0 |
0.124 |
9.1 |
0.093 |
Oxygen (% (v/v)) |
- |
20.4 |
- |
20.5 |
Nitrogen (% (v/v)) |
- |
76.9 |
- |
76.7 |
Carbon Monoxide (% (v/v)) |
- |
<0.020 |
- |
<0.020 |
Hydrogen (% (v/v)) |
- |
<0.020 |
- |
<0.020 |
Ethane (ppmv) |
- |
<1.0 |
- |
<1.0 |
Propane (ppmv) |
- |
<1.0 |
- |
<1.0 |
Butane (ppmv) |
- |
<1.0 |
- |
<1.0 |
Note: (a) Limit Levels established based on the pre-operation phase baseline and additional landfill gas monitoring results in the Pre-operation Baseline Monitoring Report. |
Table 2.35 Summary of flammable Gas surface
emission monitoring Results in the reporting period
GPS Coordinates Latitude (N) |
Longitude (E) |
Monitoring Results (ppm) |
Limit Level (ppm) |
22°16’34” |
114°16’38” |
12 |
30 |
22°16’15” |
114°16’32” |
10 |
|
The alarm of the permanent gas monitoring systems with pre-set levels
for methane at 20% lower explosive limit (LEL, equivalent to 1% methane gas
(v/v)) was not triggered at all occupied on-site buildings at SENTX in May
2025.
All
the landfill gas monitoring results were below the Limit Levels in the
reporting period. No action is thus required to be undertaken in
accordance with the Event and Action Plan presented in Annex G4.
According
to the updated EM&A Manual of the Project, the monthly landscape and visual
audit was conducted on 27 May 2025 to monitor the implementation of the
landscape and visual mitigation measures during operation/ restoration phase.
All
relevant environmental mitigation measures listed in the approved EIA Report
and the updated EM&A Manual and their implementation status are summarized
in Annex B.
The
Contractor has implemented environmental mitigation measures as stated in the
approved EIA Report and the EM&A Manual.
Regarding
the landscape and visual audit, the Contractor was reminded to maintain the
advance screen planting works regularly to ensure effective screening of views
of project works from the High Junk Peak Trail.
Site
inspections were carried out on a weekly basis with the Contractor, IEC and EPD
to monitor the implementation of proper environmental pollution control and
mitigation measures under the Project. In the reporting period, 4 site
inspections were carried out on 8, 15, 22 and 29 May 2025.
Key observations during the site inspections
are summarised in Table 2.36.
Table
2.36 Key Observations Identified during the Site Inspection in this Reporting
Month
Inspection Date |
Environmental Observations and Recommendations |
8 May
2025 |
·
The Contractor shall remove deposited silt
and grit accumulated at X10 channel near Pump House No.4 to ensure it is
functioning properly at all times. ·
The Contractor shall remove the stagnant water
and chemicals in the drip trays of Wetseps near DP4 and handle the clean-up
materials as chemical waste. |
15 May
2025 |
·
The Contractor shall arrange regular
cleaning and removal of deposited silt near DP3 access road to minimise SS
runoff to the discharge point. ·
The Contractor shall remove deposited silt
and grit accumulated at X10 channel near Pump House No.4 to ensure it is
functioning properly at all times. |
22 May
2025 |
·
The Contractor should remove the deposited
silt, grit and general refuse accumulated at X10 channel near Pump House No.4
to ensure it is functioning properly at all times. ·
The Contractor shall clean up the oil
spillage near DP6 access road and handle the clean-up materials as chemicals
waste. |
29 May
2025 |
·
The Contractor should remove the deposited
silt and grit accumulated at DP3 sediment pit to ensure it is functioning
properly at all times.
·
The Contractor shall clean up the oil
spillage near DP4 access road and handle the clean-up materials as chemicals
waste. ·
The Contractor shall remove the stagnant
water and chemicals in the drip drays of Wetseps near DP4 and handle the
clean-up materials as chemicals waste. |
The Contractor has rectified all the observations identified during
environmental site inspections in the reporting period. Key environmental
deficiencies identified and the corresponding rectification actions are
presented in Table 2.37.
Table 2.37
Summary of Environmental Deficiencies Identified and Corresponding
Rectification Actions
Deficiencies |
Rectifications Implemented |
Proposed Additional Control Measures |
Surface Water |
||
Intercepting channels & drainage system |
· Reviewed drainage plan. |
· Addition of channels. · Expedite the construction of permanent sediment trap and discharge culverts. |
DP channels (design & regular silt removal) |
· Carried out regular maintenance and cleaning of channels. · DP4 channel: Area near the channel was paved with concrete and a bund was built. · DP6 channel: Gravel piles on the channel were covered with concrete which serve as blocks for running water and to divide the channel into several sections. A pump was placed in the water zone in the upstream section to pump water to the Wetsep for treatment prior to the discharge to the last section before the weir plate. · DP6: Pipes through the gravel piles between different channel sections were covered with geotextiles to block debris and silt. |
N.A. |
Stockpiles & exposed soil |
· Installed silt fencing near surface water channel along DP6 channel. |
· Improve soil covering. · Compaction and cover for stockpiles and soil slopes. |
Wetsep (treatment capacity & number) |
· Reviewed Wetsep capacity. · Chemicals dosage of the Wetsep was increased to enhance the efficiency. |
· Install additional Wetsep. |
Backflow / ponding during heavy rainfall |
· Raised with EPD (LDG) and CEDD. |
N.A. |
The
Contractor has registered as chemical waste producer under the Contract.
Sufficient numbers of receptacles were available for general refuse collection
and sorting.
As
informed by the Contractor, waste generated during this reporting period mainly include general waste.
Reference has been made to the waste flow table prepared by the
Contractor. The quantities of different types of wastes and imported fill
materials are summarized in Table 2.38.
Table 2.38
Quantities of Different Waste Generated and Imported Fill Materials
Month/Year |
Inert
C&D Materials (a) (in ‘000m3) |
Imported
Fill |
Inert
Construction Waste Re-used |
Non-inert
Construction Waste (c) |
Recyclable
Materials (d) (in ‘000kg) |
Yard Waste (in ‘000kg) |
Chemical
Wastes |
Other,
e.g. General refuse |
|
Y Park |
SENT |
||||||||
1 – 31 May 25 |
0 |
0 |
0 |
0 |
0.22 |
0 |
0 |
0.50 |
3.33 |
Notes: (a) Inert construction wastes include hard
rock and large broken concrete, and materials disposed as public fill.
Density assumption: 1.6 (kg/L) for public fill. (b) Imported fill refers to materials
generated from other project for on-site reuse. (c) Non-inert construction wastes
include general refuse disposed at landfill. Density assumption: 0.9 (kg/L)
for general refuse. (d) Recyclable materials include metals,
paper, cardboard, plastics and others. |
A summary
of the Environmental Mitigation Implementation Schedule is presented in Annex B. The necessary
mitigation measures were implemented properly for the Project.
The
operation/ restoration phase air quality, noise, water quality and landfill gas
monitoring results complied with the Action and Limit Levels in the reporting
period.
One
exceedance of the Limit Levels for groundwater (COD) was recorded in the
reporting period. The groundwater (COD) exceedance at MWX-5 on 7 May 2025 is
under investigation.
Cumulative
statistics on exceedances is provided in Annex H.
There were
no complaints, notification of summons or prosecution recorded in the reporting
period.
Statistics
on complaints, notifications of summons, successful prosecutions are summarised
in Annex H.
As informed
by the Contractor, the major works for the Project in June 2025 will be:
·
Maintenance and improvement of temporary surface
water drainage; and
·
Restoration of Phase 1, Phase 2, Phase 3 and
Phase 4 slopes.
Potential
environmental impacts arising from the above upcoming construction activities
in the next reporting period of June 2025 are mainly associated with potential
surface water impact in the rainy season.
The
tentative schedule for environmental monitoring in June 2025 is provided in Annex I.
This EM&A Report presents the findings of the EM&A
activities undertaken during the period from 1 to 31 May 2025 in accordance
with the updated EM&A Manual and the requirements of the
Environmental Permit (EP-308/2008/D).
Air quality (24-hour
TSP, odour, thermal oxidiser, landfill gas flare and landfill gas generator
stack emission), noise, water quality (surface water, leachate and
groundwater) and landfill gas monitoring were carried out in the reporting
period. Results for air quality (24-hour
TSP, odour, thermal oxidizer, landfill gas flare and landfill gas generator),
noise and water quality (surface water and leachate), and landfill gas monitoring
complied with the Action and Limit Levels in the reporting period.
One exceedance of the Limit Levels for
groundwater (COD) was recorded in the reporting period.
Environmental site inspections were carried out during
the reporting period. Recommendations on remedial actions were given to the Contractor for the
deficiencies identified during the site inspections.
There were
no complaints, notification of summons or prosecution recorded in the reporting
period.
The ET will
keep track on the construction and operation/restoration works to confirm
compliance of environmental requirements and the proper implementation of all
necessary mitigation measures.