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 F9
INVESTIGATION REPORTS OF ENVIRONMENTAL
QUALITY LIMIT EXCEEDANCE
Annex G Landfill
Gas
Annex G2
CALIBRATION CERTIFICATES FOR LANDFILL GAS MONITORING EQUIPMENT
Annex G3
LANDFILL GAS MONITORING RESULTS
Annex G4
EVENT AND ACTION PLAN FOR LANDFILL GAS MONITORING
Annex G5
INVESTIGATION REPORTS OF ENVIRONMENTAL QUALITY LIMIT EXCEEDANCE
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 August
2024 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.
Two exceedances
of the Limit Levels for groundwater (Ammoniacal-nitrogen and Chemical Oxygen
Demand (COD)) were recorded for water quality monitoring in the reporting
period. The groundwater (Ammoniacal-nitrogen and COD) exceedances at MWX-7 on 5
August 2024 were considered non Project
related upon further investigation.
One exceedance of the Limit
Level for landfill gas (carbon dioxide) was recorded for landfill gas
monitoring in the reporting period. The landfill gas (carbon dioxide)
exceedance at LFG17 on 13 August 2024 was considered non
Project related upon further investigation.
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 September
2024 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.
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 6.5 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 August
2024 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 Cell 1X, 2X and Phase 2 Cell 3X west 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 15 August 2024; and
·
Environmental toolbox trainings on Coverage of
Regulated Electrical Equipment (REE) Expanded and Mosquito Nuisance were
provided on 8 August 2024 and 22 August 2024, respectively 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 |
|
Further
Environmental Permit |
FEP-01/308/2008/B |
Granted on 16
May 2018 |
FEP-01/308/2008/C |
Granted on 29
February 2024 |
|
Water Discharge
License under WPCO (Permit Holder: GVL) |
Licence No.: WT00041447-2022 (a) |
Validity from 17 June 2022 to 30 June 2024 (a) |
Licence No.: WT10003277-2024 (a)
|
Validity from 23 August 2024 to 30 June 2026 (a) |
|
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-RE0307-24 |
Validity from
22 March 2024 to 14 September 2024 |
(a) The renewal of WPCO Discharge License was in
progress between 1 July 2024 and 22 August 2024. As per EPD’s
confirmation, GVL is still permitted to conduct business complying with the
equipment of expired WPCO license (WT00041447-2022) as the renewal was under processing by EPD. |
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.
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 - SENTX Site Boundary (West, near 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 2.1, 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 |
•
5, 11, 17, 23, 29 Aug 2024 |
• Tisch
TE-5170 (S/N: 3976) |
AM2 |
SENTX Site Boundary (West, near 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) |
75 (23 – 107) |
260 |
260 |
AM2 - SENTX Site Boundary (West, near DP3) |
85 (27 – 151) |
260 |
260 |
AM3 - SENTX
Site Boundary (West, near RC15) |
114 (30 – 225) |
260 |
260 |
AM4 - SENTX
Site Boundary (West, near EPD building) |
55 (20 – 74) |
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: 1 Aug 2024 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 |
0 |
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 |
1 |
||
OP13 |
0 |
||
OP14 |
0 |
||
OP15 |
N/A (a) |
||
OP16 |
N/A (a) |
||
OP17 |
N/A (a) |
||
Note: (a) OP15 – OP17 are not accessible due to safety
considerations (after heavy rainstorm). |
The potential odour
source in the reporting period included the Cell 4X tipping area at SENTX. 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 |
21 Aug 2024 |
Laboratory
analysis for · Non-methane organic compounds
CO |
Quarterly for the 1st year of operation (b) |
21 Aug 2024 |
|
Laboratory
analysis for · Ammonia · Gas
combustion temperature · Exhaust
temperature · Exhaust
gas velocity (a) |
Quarterly |
21 Aug 2024 |
|
· Gas
combustion temperature · Exhaust
temperature · Exhaust gas
velocity (a) |
Continuously |
1 – 31 Aug 2024 |
|
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 |
20 Aug 2024 |
Laboratory
analysis for · Non-methane organic compounds
CO |
Quarterly for the 1st
year of operation (b) |
20 Aug 2024 |
Monitoring Location |
Parameter |
Frequency |
Monitoring Date |
Stack
of Landfill Gas Flare |
· Gas
combustion temperature · Exhaust
temperature · Exhaust
gas velocity (a) |
Continuously |
1 – 31 Aug 2024 |
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 |
20 Aug 2024 |
Laboratory
analysis for · Non-methane organic compounds |
Quarterly for the 1st year of operation (b) |
20 Aug 2024 |
|
· Exhaust
temperature · Exhaust gas
velocity (a) |
Continuously |
1 – 31 Aug 2024 |
|
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 |
0.57 gs-1 |
1.58 gs-1 |
CO |
0.03 gs-1 |
0.53 gs-1 |
SO2 |
<0.01 gs-1 |
0.07 gs-1 |
Benzene |
<2.0 x 10-4 gs-1 |
3.01 x 10-2 gs-1 |
Vinyl
chloride |
<1.3 x 10-4 gs-1 |
2.23 x 10-3 gs-1 |
Non-Methane
Organic Carbons |
<0.003 gs-1 |
- |
Ammonia |
0.0315 gs-1 |
- (c) |
Gas
combustion temperature |
900oC (895oC – 904oC) |
850oC (minimum) |
Exhaust
gas exit temperature |
1,206K (1,200K – 1,214K) |
443K (minimum) (a) |
Exhaust
gas velocity |
9.4 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 |
0.02 gs-1 |
2.43 gs-1 |
SO2 |
0.01 gs-1 |
0.22 gs-1 |
Benzene |
<1.17 x 10-4 gs-1 |
4.14 x 10-4 gs-1 |
Vinyl
chloride |
<9.4 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: 866oC
(840oC – 890oC) Flare 2: 896oC (865oC – 928oC) |
815oC (minimum) |
Exhaust gas
exit temperature |
Flare 1: 1,124K (1,096K – 1,151K) Flare 2:
1,154K (1,126K – 1,190K) |
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 |
0.018 gs-1 |
1.91 gs-1 |
CO |
0.715 gs-1 |
2.48 gs-1 |
SO2 |
0.002 gs-1 |
0.528 gs-1 |
Benzene |
3.7 x 10-5 gs-1 |
2.47 x 10-4 gs-1 |
Vinyl
chloride |
<8.9 x 10-6 gs-1 |
1.88 x 10-5 gs-1 |
Non-Methane
Organic Carbons |
0.0023 gs-1 |
- |
Exhaust
gas exit temperature |
ENGA: 868K (844K – 886K) ENGB: 866K
(837K – 875K) |
723K (minimum) (a) |
Exhaust
gas velocity |
8.8 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.
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
monitoirng
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 monitoirng details
Monitoring Station |
Location |
Parameter |
Frequency |
Monitoring Date |
AM1 |
SENTX Site Boundary (North) |
·
Methane ·
Ammonia ·
A suite of VOCs (a) ·
H2S |
Quarterly |
22 Aug 2024 |
AM2 |
SENTX Site Boundary (West, near 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 |
AM3 |
AM4 |
||
Ammonia
|
180 |
<10 |
<10 |
<10 |
<10 |
H2S |
42 |
<15 |
<15 |
<15 |
<15 |
Methane
|
NA (a) |
0.00018 %(v/v) |
0.00018
%(v/v) |
0.00018 %(v/v) |
0.00018 %(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 |
<0.3 |
<0.3 |
<0.3 |
<0.3 |
Benzene |
33 |
1.2 |
<0.5 |
<0.5 |
<0.5 |
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 |
0.7 |
1 |
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 |
1.8 |
1.9 |
1.7 |
Dimethylsulphide |
8 |
<0.2 |
<0.2 |
<0.2 |
<0.2 |
Dipropyl
ether |
NA (a) |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Limonene |
212 |
0.6 |
0.5 |
0.6 |
0.5 |
Ethanethiol |
13 |
<0.6 |
<0.6 |
<0.6 |
<0.6 |
Ethanol |
19,200 |
<3.8 |
<3.8 |
4.1 |
10.7 |
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 |
<0.5 |
<0.5 |
<0.5 |
<0.5 |
Heptane |
2,746 |
<0.8 |
<0.8 |
<0.8 |
1.5 |
Methanethiol |
10 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
Methanol |
2,660 |
17.5 |
19.2 |
34.7 |
35.1 |
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 |
1.2 |
1.8 |
1 |
0.7 |
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) |
0.9 |
<0.8 |
1.2 |
<0.8 |
Tetrachloroethylene |
1,380 |
<0.7 |
<0.7 |
<0.7 |
<0.7 |
Toluene |
1,244 |
1 |
1.1 |
0.9 |
0.7 |
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 |
1.1 |
1 |
0.8 |
0.8 |
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,
impact noise monitoring was conducted weekly at the monitoring location (i.e.
NM1) 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 |
NM1 |
SENTX Site Boundary (North) |
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, 12, 19, 26 Aug 2024 |
Sound Level
Meter: Rion NL-52
(S/N: 01010406) Acoustic
Calibrator: CAL200
(S/N: 16878) |
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 |
NM1 |
54.0 |
51.6 – 56.3 |
75 |
Major noise sources identified
during the noise monitoring included noise from operations of the SENTX and the
TKO Area 137 Fill Bank, aircrafts and insects.
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 Aug 2024 |
·
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 August 2024
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 Aug 2024 |
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 |
15 Aug 2024 |
TOA-DKK HM-30P (S/N:
790332) |
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 |
120 (102 – 144) |
>178 |
Meter No. X-2 |
112 (99 – 119) |
|
Average |
116 (104 – 132) |
|
Pump Station No. 2X (Cell 2X) |
||
Meter No. X-3 |
106 (106 – 106) |
>180 |
Meter No. X-4 |
119 (104 – 119) |
|
Average |
112 (105 – 113) |
|
Pump Station No. 3X (Cell 3X) |
||
Meter No. X-5 |
111 (99 – 119) |
> 175 |
Meter No. X-6 |
110 (99 – 119) |
|
Average |
111 (99 – 119) |
|
Pump Station No. 4X (Cell 4X) |
||
Meter No. X-7 |
114 (107 – 120) |
> 186 |
Meter No. X-8 |
113 (105 – 120) |
|
Average |
113 (106 – 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 |
29.7 |
> 43 °C |
pH
Value |
pH unit |
8.5 |
6 – 10 |
Volume
Discharged |
m³ |
1,293 |
>2,000 m³ |
Suspended
Solids (SS) |
mg/L |
26.5 |
> 800 mg/L |
Phosphate |
mg/L |
7.2 |
> 25 mg/L |
Sulphate |
mg/L |
164 |
> 800 mg/L |
Total
Inorganic Nitrogen (a) |
mg/L |
36.54 |
> 100 mg/L |
BOD |
mg/L |
7 |
> 800 mg/L |
COD |
mg/L |
872 |
> 2,000 mg/L |
Oil
& Grease |
mg/L |
<5 |
> 20 mg/L |
Boron |
µg/L |
5120 |
> 7,000 µg/L |
Iron |
mg/L |
1.33 |
> 5 mg/L |
Cadmium |
µg/L |
<1.0 |
> 1 µg/L |
Chromium |
µg/L |
97 |
> 300 µg/L |
Copper |
µg/L |
<10 |
> 1,000 µg/L |
Nickel |
µg/L |
117 |
> 700 µg/L |
Zinc |
µg/L |
62 |
> 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 monitoirng 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 |
5 August 2024 |
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 |
0.1 |
5.00 |
7 |
30 |
MWX-2 |
0.59 |
5.00 |
8 |
30 |
MWX-3 |
0.8 |
5.00 |
15 |
30 |
MWX-4 |
0.51 |
7.63 |
14 |
36 |
MWX-5 |
0.23 |
5.00 |
11 |
30 |
MWX-6 |
3.15 |
5.00 |
40 |
46 |
MWX-7 |
6.92 |
6.55 |
45 |
36 |
MWX-8 |
3.97 |
15.85 |
30 |
50 |
MWX-9 |
0.45 |
7.30 |
<20 |
71 |
MWX-10 |
N/A (a) |
5.00 |
N/A (a) |
30 |
MWX-11 |
<0.01 |
5.00 |
4 |
30 |
MWX-12 |
<0.01 |
5.00 |
3 |
30 |
MWX-13 |
0.03 |
5.00 |
2 |
30 |
MWX-14 |
0.01 |
5.00 |
4 |
30 |
Note: (a) Monitoring well MWX-10
is under maintenance. |
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. Based on the investigation
conducted for the monitoring event with potential Limit Levels exceedance with
the Contractor and the IEC, the groundwater (Ammoniacal-nitrogen and COD)
exceedances at MWX-7 on 5 August 2024 were considered non
Project related.
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 |
13 Aug 2024 |
GA5000 (S/N: G507306) |
Service voids, utilities and manholes along the Site
boundary and within the SENTX Site (UU1 to UU28) |
Monthly |
Methane
Carbon dioxide
Oxygen |
7 Aug 2024 |
GA5000 (S/N: G507306) |
Permanent gas monitoring system in all occupied
on-site buildings |
Continuous |
Methane (or flammable gas) by permanent gas monitoring
system |
1 – 31 Aug 2024 |
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 |
22 Aug 2024 |
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 |
13 Aug 2024 |
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 |
0.2 |
1.0 |
1.7 |
3.2 |
LFG2 |
0.2 |
1.0 |
1.0 |
4.3 |
LFG3 |
0.2 |
1.0 |
0.1 |
6.3 |
LFG4 |
0.1 |
1.0 |
0.0 |
7.0 |
LFG5 |
0.1 |
1.0 |
0.1 |
3.4 |
LFG6 |
0.1 |
1.0 |
0.2 |
9.1 |
LFG7 |
0.0 |
1.0 |
0.0 |
1.5 |
LFG8 |
0.0 |
12.6 |
0.1 |
2.4 |
LFG9 |
0.0 |
2.5 |
0.0 |
1.7 |
LFG10 |
0.0 |
3.5 |
0.0 |
1.6 |
LFG11 |
0.0 |
3.0 |
0.0 |
2.0 |
LFG12 |
0.0 |
13.2 |
0.0 |
1.5 |
LFG13 |
0.0 |
22.5 |
0.0 |
2.7 |
LFG14 |
0.3 |
5.2 |
0.0 |
1.8 |
LFG15 |