Contents
1.1
Background
1.2
Project Description
1.3
Scope of the EM&A
Report
1.4
Project Organisation
1.5
Summary of Construction
Works
1.6
Summary of EM&A
Programme Requirements
1.7
Status of Statutory
Environmental Compliance with the Environmental Permit
1.8
Status of Other Statutory
Environmental Requirements
2.1
Air Quality Monitoring
2.2
Noise Monitoring
2.3
Water Quality Monitoring
2.4
Landfill Gas Monitoring
2.5
Landscape and Visual Monitoring
2.6
EM&A Site Inspection
2.7
Waste Management Status
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
3.1
Construction Programme for
the Coming Month
3.2
Key Issues for the Coming
Month
3.3
Monitoring Schedule for the
Coming Month
4
Conclusion
and Recommendation
Annexes
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 D4 Meteorological
Data
Annex D5 Certificates of the
Qualified Odour Panelist
Annex D6 Odour Monitoring
Results
Annex D8 Ambient Vocs, Ammonia
And H2S Monitoring Results
Annex D9 Investigation Reports
of Environmental Quality Limit Exceedance
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 G1 Landfill Gas
Monitoring Locations for Service Voids, Utilities and Manholes Along the Site
Boundary and Within the SENTX Site
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 I Monitoring Schedule for
the Next Reporting Period
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. ERM-Hong Kong, Limited (ERM) is
commissioned to undertake the role of Environmental Team (ET) for the
construction, operation/restoration and aftercare of SENTX Project (“the
Project”) in accordance with the requirements specified in the Environmental
Permit (EP), updated Environmental Monitoring and Audit (EM&A) Manual, the
approved Environmental Impact Assessment (EIA) Report of the Project taking
account of the latest design and other relevant statutory requirements. The
construction (not including works related to site clearance and preparation)
and operation of the Project commenced on 2 January 2019 and 21 November 2021,
respectively.
This
Monthly EM&A report presents the EM&A works carried out during the
period from 1 to 31 May 2023 for the Project in accordance with the updated
EM&A Manual.
Exceedance
of Action and Limit Levels for Air Quality
One
exceedance of Action and Limit Levels for Total Suspended Particulates (TSP)
and one exceedance of Limit Levels for landfill gas flare stack emission
(Benzene) were recorded for air quality monitoring in the
reporting period. The TSP exceedance at AM2 on 1 May 2023 was considered
Project-related upon further investigation. The landfill gas flare stack emission
(Benzene) exceedance on 12 May 2023 was considered Project-related upon
further investigation.
Exceedance
of Action and Limit Levels for Noise
No
exceedance of Action and Limit Levels for operation/restoration phase noise
monitoring was recorded in the reporting period.
Exceedance
of Action and Limit Levels for Water Quality
Two exceedances of the Limit Level
for groundwater (Chemical Oxygen Demand (COD)) were recorded for water quality
impact monitoring in the reporting period. The groundwater
(COD) exceedances at MWX-5 and MWX-8 on 4 May 2023
were considered non Project-related upon further investigation.
Exceedance
of Action and Limit Levels for Landfill Gas
No
exceedance of Action and Limit Levels for operation/restoration phase landfill
gas monitoring was recorded in the reporting period.
Environmental
Complaints, Summons and Prosecutions
There
were no complaints, notification of summons or prosecution recorded in the
reporting period.
Reporting
Change
There was no reporting change in the
reporting period.
Future
Key Issues
Potential
environmental impacts arising from the upcoming construction/ operational
activities in the next reporting period of June 2023 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).
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 |
2057 |
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
2023 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:
·
Rectification of latent
defects at Landfill Gas (LFG) Plant and Leachate Treatment Plant (LTP);
·
Construction of SENT soil
bench tie in;
·
Deployment of liner system
at rockwall buttress bench 2;
·
Maintenance and improvement
of temporary surface water drainage;
·
Civil and E&M works for Diesel Fuel Tank, such as canopy, pumps and
equipment installation; and
·
Rectification of
outstanding minor items for weighmaster house and guard house.
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, ER, ET, IEC and
EPD on 18 May 2023; and
·
Environmental
toolbox trainings on Air Pollution (Dark Smoke) and Waste Reduction
in Construction Industry were
provided on 16 May 2023 and 23 May 2023, 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 |
|
Further
Environmental Permit |
FEP-01/308/2008/B |
Granted on 16
May 2018 |
Water
Discharge License under WPCO (Permit Holder: GVL) |
Licence No.:
WT00041447-2022 |
Validity from
17 June 2022 to 30 June 2024 |
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-RE0245-23 |
Validity from
15 March 2023 to 14 September 2023 |
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 |
1,
7, 13, 19, 25, 31 May 2023 |
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 |
Average 24-hr TSP
Concentration (µg m-3) (Range in bracket) |
Action Level
(µg/m3) |
Limit Level
(µg/m3) |
AM1 - SENTX Site Boundary
(North) |
150 (113 – 221) |
260 |
260 |
AM2 - SENTX Site Boundary
(West, near DP3) |
157 (57 – 356) |
260 |
260 |
AM3 - SENTX Site Boundary
(West, near RC15) |
112 (59 – 173) |
260 |
260 |
AM4 - SENTX Site Boundary
(West, near EPD building) |
97 (65 – 119) |
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.
Action
and Limit Levels exceedance was recorded for TSP monitoring in the reporting
period and actions in accordance with the Event and Action Plan presented
in Annex D3 were undertaken. Investigation of
the Action and Limit Levels exceedance was conducted and the investigation
reports are presented in Annex D9.
Based on the investigation
conducted for the monitoring events with potential Action and Limit Levels
exceedance with the Contractor and the IEC, the TSP exceedance at AM2 on 1 May
2023 was considered 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.
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.
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: 22
May 2023 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 |
1 |
|
|
OP15 |
1 |
|
|
OP16 |
1 |
|
|
OP17 |
0 |
|
|
The
potential odour source in the reporting period included the
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 |
11
May 2023 |
Laboratory analysis for ·
Non-methane organic compounds |
Quarterly for the 1st year of operation (b) |
11
May 2023 |
|
Laboratory analysis for ·
Ammonia |
Quarterly |
11
May 2023 |
|
·
Gas combustion temperature ·
Exhaust temperature ·
Exhaust gas velocity (a) |
Continuously |
1 – 31 May
2023 |
|
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 |
12
May 2023 |
Laboratory analysis for ·
Non-methane organic compounds |
Quarterly for the 1st year of operation (b) |
12
May 2023 |
|
·
Gas combustion temperature ·
Exhaust temperature ·
Exhaust gas velocity (a) |
Continuously |
1 – 31 May
2023 |
|
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 |
12
May 2023 |
Laboratory analysis for ·
Non-methane organic compounds |
Quarterly for the 1st year of operation (b) |
12
May 2023 |
|
·
Exhaust temperature ·
Exhaust gas velocity (a) |
Continuously |
1 – 31 May
2023 |
|
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
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 |
0.35
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 |
1.0
x 10-4 gs-1 |
3.01
x 10-2 gs-1 |
Vinyl
chloride |
<1.0
x 10-4 gs-1 |
2.23
x 10-3 gs-1 |
Non-Methane
Organic Carbon |
<3.0
x 10-3 gs-1 |
- |
Ammonia |
0.0227
gs-1 |
- (c) |
Gas
combustion temperature |
874oC
(855oC – 922oC) |
850oC
(minimum) |
Exhaust
gas exit temperature |
1,265K
(1,246K – 1,282K) |
443K
(minimum) (a) |
Exhaust
gas velocity |
9.3
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 |
0.03
gs-1 |
0.97
gs-1 |
CO |
0.33
gs-1 |
2.43
gs-1 |
SO2 |
<0.01
gs-1 |
0.22
gs-1 |
Benzene |
<4.47
x 10-4 gs-1 |
4.14
x 10-4 gs-1 |
Vinyl
chloride |
<1.07
x 10-4 gs-1 |
2.60
x 10-4 gs-1 |
Non-Methane
Organic Carbon |
0.003
gs-1 |
- |
Gas
combustion temperature |
Flare
1: 879oC (820oC – 990oC) Flare
2: 878oC (830oC – 920oC) |
815oC
(minimum) |
Exhaust
gas exit temperature |
Flare 1: 1,059K
(1,003K – 1,163K) Flare 2: 1,078K
(1,003K – 1,123K) |
923
K (minimum) (a) |
Exhaust
gas velocity |
8.7
ms-1 (b) |
9.0
m s-1 (minimum) (a) |
Note: (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 |
0.030
gs-1 |
1.91
gs-1 |
CO |
0.853
gs-1 |
2.48
gs-1 |
SO2 |
<0.001
gs-1 |
0.528
gs-1 |
Benzene |
5.9
x 10-5 gs-1 |
2.47
x 10-4 gs-1 |
Vinyl
chloride |
<1.2
x 10-5 gs-1 |
1.88
x 10-5 gs-1 |
Non-Methane
Organic Carbons |
1.9
x 10-3 gs-1 |
- |
Exhaust
gas exit temperature |
ENGA: 873K (862K
– 879K) ENGB : 865K (860K
– 870K) |
723K
(minimum) (a) |
Exhaust
gas velocity |
12.9
ms-1 (b) |
30.0
ms-1 (minimum) (a) |
Note: (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. |
Limit Level
exceedance was recorded for landfill gas flare stack emission monitoring in the
reporting period and actions in accordance with the Event and Action Plan
presented in Annex D3 were undertaken. Investigation of
the Limit Levels exceedance was conducted and the investigation reports are
presented in Annex D9.
Based on the investigation conducted for the
monitoring events with potential Limit Levels exceedances with the Contractor
and the IEC, the landfill
gas flare stack emission (Benzene) exceedance on 12 May 2023 was
considered Project-related upon further 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, 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 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 |
Notes: (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.
Methane
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.
Ammonia
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
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 |
11
May 2023 |
|
||
AM2 |
SENTX Site Boundary (West,
near DP3) |
|
|||||
AM3 |
SENTX Site Boundary (West, near RC15) |
|
|||||
AM4 |
SENTX Site Boundary (West, near EPD building) |
|
|||||
Notes: (a) A suite of VOCs includes: |
|
||||||
·
Trichloroethylene ·
Vinyl
chloride ·
Methylene
chloride ·
Chloroform ·
1,2-dichloroethane ·
1,1,1-trichloroethane ·
Carbon
tetrachloride ·
Tetrachloroethylene ·
1,2-dibromoethane ·
Benzene ·
Toluene ·
Carbon
disulphide ·
Propyl
benzene ·
Ethyl
benzene |
·
Butyl
benzene ·
Xylenes ·
Decanes ·
Undecane ·
Limonene ·
Terpenes ·
Ethanol ·
Butan-2-ol ·
Dimethylsulphide ·
Methyl
propionate ·
Ethyl
propionate ·
Propyl
propionate ·
Butyl
acetate ·
Ethyl
butanoate |
·
Dichlorobenzene ·
Methyl
butanoate ·
Dipropyl
ether ·
Methanethiol ·
Ethanethiol ·
Butanethiol ·
Methanol ·
Heptanes ·
Octanes ·
Nonanes ·
Dichlorodifluoro-methane ·
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 summarised in Table
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 |
64 |
55 |
82 |
66 |
H2S |
42 |
<15 |
<15 |
<15 |
<15 |
Methane |
NA (a) |
0.00021
%(v/v) |
0.00016
%(v/v) |
0.00021
%(v/v) |
0.00017
%(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 |
0.4 |
0.4 |
0.5 |
0.4 |
Benzene |
33 |
0.6 |
1 |
0.6 |
0.7 |
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 |
0.8 |
0.7 |
1.2 |
Carbon Tetrachloride |
64 |
0.7 |
0.8 |
0.8 |
0.8 |
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) |
1.9 |
2.2 |
2.1 |
2.3 |
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 |
<0.4 |
0.5 |
<0.4 |
Ethanethiol |
13 |
<0.6 |
<0.6 |
<0.6 |
<0.6 |
Ethanol |
19,200 |
<3.8 |
5.7 |
7 |
15 |
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 |
0.6 |
1.9 |
<0.5 |
Heptane |
2,746 |
<0.8 |
<0.8 |
<0.8 |
<0.8 |
Methanethiol |
10 |
<0.4 |
<0.4 |
<0.4 |
<0.4 |
Methanol |
2,660 |
<2.6 |
31.1 |
37.7 |
41.5 |
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 |
1.4 |
1.5 |
3.8 |
7.9 |
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 |
1.1 |
<0.8 |
Tetrachloroethylene |
1,380 |
<0.7 |
<0.7 |
<0.7 |
<0.7 |
Toluene |
1,244 |
1.5 |
1.4 |
1.9 |
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 |
0.8 |
1 |
3 |
0.9 |
Notes: (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 (1) |
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 |
2,
8, 15, 22, 29 May 2023 |
Sound
Level Meter: Rion
NL-52 (S/N: 00131627) Acoustic
Calibrator: CAL200
(S/N: 15678) |
The
schedule for noise monitoring during the reporting period is provided in Annex C.
A
total of 5 impact noise monitoring events were scheduled during the reporting
period. However, noise monitoring on 8 May 2023 was cancelled due to
adverse weather condition. 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.