1 Introduction
1.1 Purpose of the Report
1.2 Structure of the Report
2 Project
information
2.1 Background
2.2 General Site Description
2.3 Major Activities Undertaken
2.4 Project Organisation and Management
Structure
2.5 Status of Environmental Approval
Documents
3 Environmental Monitoring and Audit Requirements
3.1 Environmental Monitoring
3.1.1 Air Quality
3.1.2 Odour
3.2 Site Audit
3.2.1 Water
Quality
3.2.2 Landscape
and Visual
4 Monitoring
Results
4.1 Air Quality
4.1.1 Commissioning
Phase Monitoring
4.1.2 Operation
Phase Monitoring
4.2 Odour
4.2.1 Operation
Phase Monitoring
4.3 Water Quality
4.3.1 Operation
Phase Monitoring
4.4 Waste Management
4.4.1 Operation
Phase Monitoring
5 Site Audit
5.1 Environmental Site Audit
5.1.1 Operation Phase
5.2 Landscape and Visual Audit
6 Environmental Non-conformance and
Deficiencies
6.1 Summary of Environmental
Non-Compliance and Deficiencies
6.2 Summary of Environmental Complaint
6.3 Summary of Environmental Summon and
Successful Prosecution
7 Future Key
Issues
7.1 Key Issues for the Coming Month
8 Conclusions
Table 2.1 Summary of Activities Undertaken in the Reporting Period
Table 2.2 Summary of Environmental Licensing, Notification and Permit Status
Table 3.1 Sampling and Laboratory Analysis Methodology
Table 3.2 Emission Limit for CAPCS Stack
Table 3.3 Emission Limit for CHP Stack
Table 3.4 Emission Limit for ASP Stack
Table 3.5 Emission Limit for Standby Flaring Gas Unit ()
Table 3.6 Odour Intensity Level
Table 3.7 Action and Limit Levels for Odour Nuisance
Table 3.8 Event and Action Plan for Odour Monitoring
Table 3.9 Discharge Limits for Effluent
Table 4.1 Hourly Average of Parameters Recorded for CAPCS
Table 4.2 Hourly Average of Parameters Recorded for CHP 1
Table 4.3 Hourly Average of Parameters Recorded for CHP 2
Table 4.4 Hourly Average of Parameters Recorded for CHP 3
Table 4.5 Hourly Average of Parameters Recorded for ASP
Table 4.6 Results of the Discharge Sample
Table 4.7 Quantities of Waste Generated from the Construction of the Project
Table 4.8 Quantities of Waste Generated from the Operation of the Project
EXECUTIVE SUMMARY
The construction works
of No. EP/SP/61/10 Organic Resources Recovery Centre Phase 1 (the Project) commenced
on 21 May 2015. This is the 71st monthly Environmental Monitoring
and Audit (EM&A) report presenting the EM&A works carried out during
the period from 1 to 30 April 2021 in accordance with the EM&A Manual.
Substantial completion of the construction works was confirmed on 3 December
2018. In the meantime, the operation phase EM&A programme had commenced in
March 2019. Substantial Completion in respect of substantial part of the Works
was confirmed on 24 February 2020. The construction phase EM&A programme
was completed in the end of February 2020.
Summary of Works
undertaken during the Reporting Month
Works undertaken in the
reporting month included:
· Operation of
the Project, including organic waste reception, and operation of the
pre-treatment facilities, anaerobic digesters, composting facilities, air
pollution control systems, on-line emission monitoring system for the
Centralised Air Pollution Control Unit (CAPCS), Co-generation Units (CHP)s and
Ammonia Stripping Plant (ASP), and the wastewater treatment plant; and
· Process
fine-tune, including adjustment of the ASP with new treatment media,
modification of Continuous Environmental Monitoring System (CEMS) and
Supervisory Control and Data Acquisition System (SCADA) rectification and
improvement works following equipment failures and the alteration of different
operation modes and measures to adapt to the high variation of SSOW nature and
sources.
Environmental
Monitoring and Audit Progress
Air Quality Monitoring
Exceedances on NOx,
SO2, VOC and HCl from CHP and CO, NOx, SO2
and NH3 from ASP were recorded on the on-line
monitoring system. It should be noted that measurements recorded under
abnormal operating conditions, e.g. start up and stopping of stacks, unstable
operation, test runs and interference of sensor, are disregarded.
Exceedances in emission
parameters of CHP were found to be a result of low biogas loading and unstable
performance at CHP. The exceedances of ASP were found to be a result of
malfunction of its thermal destructor and the incomplete combustion of biogas
at ASP.
The Contractor has
implemented mitigation measures to control the exceedance including regular
maintenance of the CHP by the supplier and regular fine-tuning, finding better
and more feedstock to increase biogas loading and testing at ASP to optimise
combustion efficiency and overall performance.
The Contractor is
recommended to closely monitor the processes of the modification of the CHP and
ASP and the post-modification monitoring of emission level to avoid any
exceedance.
Water Quality
No
non-compliance to the effluent discharge limit stipulated in the discharge
licence issued by the EPD under the Water Pollution Control Ordinance
was recorded during this reporting period.
Waste Management
Waste generated from
the operation of the Project includes chemical waste, waste generated from
pre-treatment process and general refuse.
9,700 L of chemical
waste was collected by licenced waste collector from the operation of the
Project.
651.29 tonnes of waste
generated from pre-treatment process from the operation of the Project was
disposed of at landfill. Among the recyclable waste generated from
pre-treatment process from the operation of the Project, 0.00 tonne of metals,
0.00 tonnes of papers/
cardboard packing and 0.00 tonne of plastics were sent to recyclers for
recycling during the reporting period.
Around 2.53 tonnes of
general refuse from the operation of the Project was disposed of at landfill.
Among the recycled general refuse from the operation of the Project, 0.00 tonne of metals,
0.00 tonne
of
papers/ cardboard packing and 0.00 tonne of plastics were sent
to recyclers for recycling during the reporting period.
Findings of
Environmental Site Audit
A summary of the monitoring activities undertaken in this
reporting period is listed below:
|
·
Joint
Environmental Site Inspections
|
1 time
|
1 monthly
joint environmental site inspections were carried out by the representatives of
the Contractor and the MT. The IEC and ER were also present at the joint
inspections on
23 April 2021. The environmental control/ mitigation measures (related to air
quality, water quality, waste (including land contamination prevention),
hazard-to-life and landscape and visual) recommended in the approved EIA Report
and the EM&A Manual were properly implemented by the Contractor during the
reporting month.
Environmental
Exceedance/Non-conformance/Compliant/Summons and Prosecution
Exceedances for the air
emission limits for the CHP and ASP stacks were recorded during the reporting
period.
No complaint/ summon/prosecution
was received in this reporting period.
Future Key Issues
Activities to be
undertaken in the next reporting month include:
·
Operation
of the Project.
·
Modification
of the CHP and ASP to control the air emission.
2
Introduction
ERM-Hong Kong, Limited (ERM) was appointed
by OSCAR Bioenergy Joint Venture (the Contractor) as the Environmental Team
(ET) to undertake the construction Environmental Monitoring and Audit
(EM&A) programme for the Contract No. EP/SP/61/10 of Organic Waste
Treatment Facilities Phase I, which the project name has been updated
to Organic Resources Recovery Centre (Phase I) (the
Project) since November 2017. ERM was also appointed by
the Contractor to undertake the operation EM&A programme starting 1 March
2019.
This is the 71st EM&A
report which summarises the monitoring results and audit findings for the
EM&A programme during the reporting period from 1 to 30 April 2021.
The structure of the report is as follows:
Section 1: Introduction
It details the scope and structure of the
report.
Section 2: Project
Information
It
summarises the background and scope of the Project, site description, project
organisation and status of the Environmental Permits (EP)/licences.
Section 3: Environmental
Monitoring and Audit Requirements
It summarises the
environmental monitoring requirements including monitoring parameters,
programmes, methodologies, frequency, locations, Action and Limit Levels,
Event/Action Plans, as well as environmental audit requirements as recommended
in the EM&A Manual and approved EIA report.
Section 4: Monitoring
Results
It summarises
monitoring results of the reporting period.
Section 5: Site
Audit
It summarises the audit
findings of the environmental as well as landscape and visual site audits
undertaken within the reporting period.
Section 6: Environmental
Non-conformance
It summarises any
exceedance of environmental performance standard, environmental complaints and
summons received within the reporting period.
Section 7: Further
Key Issues
It summarises the
impact forecast for the next reporting month.
Section 8: Conclusions
3
Project
information
The Organic Resources Recovery Centre
(ORRC) Phase I development (hereinafter referred to as “the Project”) is to
design, construct and operate a biological treatment facility with a capacity
of about 200 tonnes per day and convert source-separated organic waste from
commercial and industrial sectors (mostly food waste) into compost and biogas
through proven biological treatment technologies. The location of the Project
site is shown in Annex
A.
The environmental
acceptability of the construction and operation of the Project had been
confirmed by findings of the associated Environmental Impact Assessment (EIA)
Study completed in 2009. The Director of Environmental Protection (DEP)
approved this EIA Report under the Environmental Impact Assessment Ordinance
(EIAO) (Cap. 499) in February 2010 (Register No.: AEIAR-149/2010) (hereafter referred to as the approved EIA Report).
Subsequent Report on Re-assessment on Environmental Implications and Report on
Re-assessment on Hazard to Life Implications were completed in 2013,
respectively.
An Environmental Permit (EP)
(No. EP-395/2010) was issued by the DEP to the EPD (Project Team), the
Permit Holder, on 21 June 2010 and varied on 18 March 2013 (No. EP-395/2010/A)
and 21 May 2013 (No. EP-395/2010/B), respectively. The Design Build and
Operate Contract for the ORRC Phase 1 (Contract No. EP/SP/61/10 Organic Resources
Recovery Centre (Phase 1) (the Contract)) was awarded to SITA Waste Services
Limited, ATAL Engineering Limited and Ros-Roca, Sociedad Anonima jointly
trading as the OSCAR Bioenergy Joint Venture (OSCAR or the Contractor). A
Further EP (No. FEP-01/395/2010/B) was issued by the DEP to the OSCAR on 16
February 2015. Variation to both EPs (Nos. EP-395/2010/B and
FEP-01/395/2010/B) were made in December 2015. The latest EPs, Nos.
EP-395/2010/C and FEP-01/395/2010/C, were issued by the DEP on 21 December 2015.
Under the requirements of
Condition 5 of the EP (No. FEP-01/395/2010/C), an Environmental Monitoring and
Audit (EM&A) programme as set out in the approved EM&A Manual
(hereinafter referred to as EM&A Manual) is required to be implemented
during the construction and operation of the Project. ERM-Hong Kong, Ltd (ERM)
has been appointed by OSCAR as the Environmental Team (ET) for the construction
phase EM&A programme and the Monitoring Team (MT) for the operation phase
EM&A programme for the implementation of the EM&A programme in accordance
with the requirements of the EP and the approved EM&A Manual.
The
construction works commenced on 21 May 2015. The operation phase of the
EM&A programme commenced on 1 March 2019 (). The
construction phase EM&A programme was completed in the end of February
2020.
The Project Site is located at Siu Ho Wan
in North Lantau with an area of about 2 hectares. The layout of the Project
Site is illustrated in Annex
A.
The facility received and treated an average of 100 tonnes of source separated
organic waste per day during the reporting month.
A summary of the major activities
undertaken in the reporting period is shown in Table 2.1.
Table 2.1 Summary
of Activities Undertaken in the Reporting Period
|
Activities
Undertaken in the Reporting Period
|
|
·
Systems
being operated – waste reception, pre-treatment, CAPCS extraction, the
digesters, the centrifuge, , the composting tunnels the desulphurisation, the
emergency flare, the CHPs, the ASP and the biological waste water treatment
plant (about 100-130 t/d SSOW input); and
·
Process
fine-tune – adjustment of the ASP operational parameters with new treatment
media, CEMS/SCADA modification and improvement work following equipment
failures and the alteration of different operation modes and measures to
adapt to the high variation of SSOW nature and sources.
|
3.4
Project Organisation
and Management Structure
The project organisation chart and contact
details are shown in Annex
B.
A summary of the valid permits, licences,
and/or notifications on environmental protection for this Project is presented
in Table 2.2.
Table
2.2 Summary
of Environmental Licensing, Notification and Permit Status
|
Permit/ Licences/
Notification
|
Reference
|
Validity Period
|
Remarks
|
|
Environmental Permit
|
FEP-01/395/2010/C
|
Throughout the Contract
|
Permit granted on 21 December 2015
|
|
Effluent Discharge License
|
WT00024352-2016
|
3 June 2016 – 30 June 2021
|
Approved on 3 June 2016
|
|
Chemical
Waste Producer Registration
|
WPN
5213-961-O2231-02
|
Throughout
the implementation of the Project
|
Approved
on 10 November 2017
|
|
Waste Disposal Billing Account
|
Account number: 702310
|
Throughout the Contract
|
-
|
4
Environmental
Monitoring and Audit Requirements
The air quality (including odour)
monitoring to be carried out during the commissioning and operation phase of
the Project are described below. Although water quality monitoring is not
required for the operation phase under the EM&A programme, there are water
quality monitoring requirement under the Water Discharge Licence of the plant
under the Water Pollution Control Ordinance (WPCO). As part of this
EM&A programme, the monitoring results will be reviewed to check the
compliance with the WPCO requirements.
4.1.1
Air
Quality
According to the EM&A Manual and EP
requirements, stack monitoring are required during the commissioning and operation
phase of the Project.
On-line monitoring (using continuous
environmental monitoring system (CEMS) shall be carried out for the centralised
air pollution unit (CAPCS), cogeneration units (CHP) and the ammonia stripping
plant (ASP) during the commissioning and operation phase. The calibration
certificate for the on-line monitoring equipment is provided in Annex C.
The monitoring data is transmitted
instantaneously to EPD (Regional Office) by telemetry system.
When the on-line monitoring for certain
parameter cannot be undertaken, monitoring will be carried out using the
following methodology approved by the EPD.
Table
3.1 Sampling
and Laboratory Analysis Methodology
|
Parameters
|
Method
|
Stacks
to be Monitored
|
|
Gaseous
and vaporous organic substances (including methane)
|
USEPA
Method 18
|
·
CAPCS
·
CHP
·
ASP
|
|
Particulate
|
USEPA
Method 5
|
·
CAPCS
·
CHP
·
ASP
|
|
Carbon
monoxide (CO)
|
USEPA Method 10
|
·
CHP
·
ASP
|
|
Nitrogen
oxides (NOx)
|
USEPA
Method 7E
|
·
CHP
·
ASP
|
|
Sulphur
dioxide (SO2);
|
USEPA
Method 6
|
·
CHP
·
ASP
|
|
Hydrogen
chloride (HCl)
|
USEPA
Method 26A
|
·
CHP
·
ASP
|
|
Hydrogen
fluoride (HF)
|
USEPA
Method 26A
|
·
CHP
·
ASP
|
|
Oxygen
(O2);
|
USEPA
Method 3A
|
·
CAPCS
·
CHP
·
ASP
|
|
Velocity
and Volumetric Flow
|
USEPA
Method 2
|
·
CAPCS
·
CHP
·
ASP
|
|
Ammonia
(NH3)
|
USEPA
CTM 027
|
·
ASP
|
|
Odour
(including NH3 and H2S)
|
EN
13725
|
·
CAPCS
|
|
Water
vapour content (continuous measurement of the water vapour content should not
be required if the sample exhaust gas is dried before the emissions are
analysed)
|
USEPA
Method 4
|
·
CAPCS
·
CHP
·
ASP
|
|
Temperature
|
USEPA
Method 4
|
·
CAPCS
·
CHP
·
ASP
|
With reference to the EM&A Manual, the
air emission of the stacks shall meet the following emission limits as
presented in Tables 3.2 to 3.5.
Table 3.2 Emission
Limit for CAPCS Stack
|
Parameter
|
Emission
Level (mg/Nm3) (a)
|
|
VOCs (including methane)
|
680
|
|
Dust
(or Total Suspended Particulates
(TSP))
|
6
|
|
Odour (including
NH3 & H2S)
|
220
(b)
|
|
Notes:
(a) Hourly
average concentration
(b) The
odour unit is OU/Nm3
|
Table
3.3 Emission
Limit for CHP Stack
|
Parameter
|
Maximum
Emission Level (mg/Nm3) (a) (b)
|
|
Dust
(or Total Suspended Particulates)
|
15
|
|
Carbon
Monoxide
|
650
|
|
NOx
|
300
|
|
SO2
|
50
|
|
NMVOCs (c)
|
150
|
|
VOCs (including methane) (d)
|
1,500
|
|
HCl
|
10
|
|
HF
|
1
|
|
Notes:
(a) All values refer to an oxygen content in the exhaust
gas of 6% and dry basis.
(b) Hourly average concentration
(c) NMVOCs should be monitored by gas sampling and
laboratory analysis at an agreed interval. For the first 12 months (starting
from August 2019), monitoring should be carried out at quarterly intervals.
The monitoring frequency should then be reduced to half-yearly for next 12
months (starting from August 2020).
(d) The VOCs emission limit include methane as biogas is
adopted as fuel in the combustion process.
|
Table
3.4 Emission
Limit for ASP Stack
|
Parameter
|
Maximum Emission
Level (mg/Nm3) (a) (b)
|
|
Dust
(or Total Suspended Particulates)
|
5
|
|
Carbon
Monoxide
|
100
|
|
NOx
|
200
|
|
SO2
|
50
|
|
VOCs (including methane) (c)
|
20
|
|
NH3
|
35
|
|
HCl
|
10
|
|
HF
|
1
|
|
Notes:
(a) All
values refer to an oxygen content in the exhaust gas of 11% and dry basis.
(b) Hourly
average concentration
(c) The
VOCs emission limit include methane as biogas is adopted as fuel in the
combustion process.
|
Table 3.5 Emission
Limit for Standby Flaring Gas Unit ([2])
|
Parameter
|
Maximum
Emission level (mg/Nm3) (a) (b)
|
|
Dust
(or Total Suspended Particulates)
|
5
|
|
Carbon
Monoxide
|
100
|
|
NOx
|
200
|
|
SO2
|
50
|
|
VOCs
(including methane) (c)
|
20
|
|
HCl
|
10
|
|
HF
|
1
|
|
Notes:
(a) All
values refer to an oxygen content in the exhaust gas of 11% and dry basis.
(b) Hourly
average concentration
(c) The
VOCs emission limit include methane as biogas is adopted as fuel in the
combustion process.
|
To determine
the effectiveness of the proposed odour mitigation measures and to ensure that
the operation of the ORRC1 will not cause adverse odour impacts, odour
monitoring of the CAPCS stack (see Section 3.1.1) and odour patrol will
be carried out.
Odour patrol shall be conducted by
independent trained personnel/ competent persons in summer months (i.e. from
July to September) for the first two operational years of ORRC1 at monthly
intervals along an odour patrol route at the Project Site boundary as shown in Annex A().
The perceived odour intensity is divided
into 5 levels. Table 3.6 describes the odour intensity for different
levels.
Table 3.6 Odour
Intensity Level
|
Level
|
Odour Intensity
|
|
0
|
Not
detected. No odour
perceived or an odour
so weak that it cannot be easily
characterised or described
|
|
1
|
Slight identifiable
odour, and slight
chance to have odour
nuisance
|
|
2
|
Moderate identifiable odour, and
moderate chance to have odour nuisance
|
|
3
|
Strong identifiable,
likely to have odour nuisance
|
|
4
|
Extreme severe odour, and unacceptable odour level
|
Table 3.7 shows the
action level and limit level to be used for odour patrol. Should any exceedance
of the action and limit levels occurs, actions in accordance with the event and
action plan in Table 3.8 should be carried out.
Table 3.7 Action
and Limit Levels for Odour Nuisance
|
Parameter
|
Action
Level
|
Limit
Level
|
|
Odour
Nuisance (from odour patrol)
|
When
one documented compliant is received (a), or Odour Intensity
of 2 is measured
from odour patrol.
|
Two or
more documented complaints
are received (a) within a week; or
Odour intensity of 3 or above is measured
from odour patrol.
|
|
Note:
(a)
Once the complaint is received by the Project
Proponent (EPD), the Project Proponent would investigate and verify the
complaint whether it is related to the potential odour emission from the
ORRC1 and its on-site wastewater treatment unit.
|
Table 3.8 Event
and Action Plan for Odour Monitoring
|
Event
|
Action
|
|
|
Person-in-charge of Odour Monitoring
|
Project
Proponent (a)
|
|
Action
Level
|
|
|
|
Exceedance
of action level (Odour Patrol)
|
1.
Identify source/reason of exceedance;
2.
Repeat odour patrol to confirm finding.
|
1.
Carry out investigation to identify the source/reason of exceedance.
Investigation should be completed within 2 weeks;
2.
Rectify any unacceptable practice;
3.
Implement more mitigation measures if necessary;
4.
Inform Drainage Services Department (DSD) or the operator of the Siu Ho Wan
Sewage Treatment Works (SHWSTW) if exceedance is considered to be caused by
the operation of the SHWSTW.
5.
Inform North Lantau Refuse Transfer Station (NLTS) operator if exceedance is
considered to be caused by the operation of NLTS.
|
|
Exceedance
of action level (Odour Complaints)
|
1.
Identify source/reason of exceedance;
2.
Carry out odour patrol to determinate odour intensity.
|
1.
Carry out investigation and verify the complaint whether it is related to
potential odour emission from the nearby SHWSTW;
2.
Carry out investigation to identify the source/reason of exceedance.
Investigation should be completed within 2 weeks;
3.
Rectify any unacceptable practice;
4.
Implement more mitigation measures if necessary;
5.
Inform DSD or the operator of the SHWSTW if exceedance is considered to be
caused by the operation of the SHWSTW.
6.
Inform NLTS operator if exceedance is considered to be caused by the operation
of NLTS.
|
|
Limit
Level
|
|
|
|
Exceedance
of limit level
|
1.
Identify source/reason of exceedance;
2.
Inform EPD;
3.
Repeat odour patrol to confirm findings;
4.
Increase odour patrol frequency to bi-weekly;
5.
Assess effectiveness of remedial action and keep EPD informed of the results;
6.
If exceedance stops, cease additional odour patrol.
|
1.
Carry out investigation to identify the source/reason of exceedance.
Investigation should be completed within 2 week;
2.
Rectify any unacceptable practice;
3.
Formulate remedial actions;
4.
Ensure remedial actions properly implemented;
5.
If exceedance continues, consider what more/enhanced mitigation measures
should be implemented;
6.
Inform DSD or the operator of the SHWSTW if exceedance is considered to be
caused by the operation of the SHWSTW.
|
|
Note:
(a) Project
Proponent shall identify an implementation agent.
|
Environmental mitigation measures (related
to air quality, water quality, waste, land contamination, hazard-to-life, and
landscape and visual) to be implemented during the operation phase of the
Project are recommended in the approved EIA Report and EM&A Manual and are
summarised in Annex
D. Monthly site audits for operation phase will be carried out to
check the implementation of these measures.
Compliance audits are to be undertaken to
ensure that a valid discharge licence has been issued by EPD prior to the
discharge of effluent from the operation of the Project site. The audit shall
be conducted to ensure that the effluent quality is in compliance with the
discharge licence requirements. The effluent quality shall meet the discharge
limits as described in Table 3.9.
Table 3.9 Discharge
Limits for Effluent
|
Parameters
|
Discharge
Limit (mg/L)
|
|
Flow
Rate (m3/day)
|
685
|
|
pH
(pH units)
|
6-10
(a)
|
|
Suspended
Solids
|
800
|
|
Biochemical
Oxygen Demand (5 days, 20°)
|
800
|
|
Chemical
Oxygen Demand
|
2,000
|
|
Oil
& Grease
|
40
|
|
Total
Nitrogen
|
200
|
|
Total
Phosphorus
|
50
|
|
Surfactants
(total)
|
25
|
|
Note:
(a) Range.
|
In accordance with EM&A Manual, the
landscape and visual mitigation measures shall be implemented.
For operation phase, site inspection shall
be conducted once a month for the first year of operation of the Project. All
measures as stated in the implementation schedule of the EM&A Manual (see Annex D),
including compensatory planting, undertaken by both the Contractor and the
specialist Landscape Sub-Contractor during the first year of the operation
phase shall be audited by a Registered Landscape Architect (RLA) to ensure
compliance with the intended aims of the measures and the effectiveness of the
mitigation measures. After the one-year maintenance period, the landscape
maintenance and monitoring shall be carried out by the Contractor.
5
Monitoring
Results
Monitoring results of air quality
parameters from stack emissions of the centralised air pollution control
system, the ammonia stripping plant and the cogeneration units will be provided
once available to show compliance with the monitoring requirements stated in
the EM&A Manual (Rev. F) to support the termination of the commissioning
phase EM&A programme.
The concentrations of concerned air
pollutants emitted from the stacks of the CAPCS, CHP, and ASP during the
reporting period are monitored on-line by the continuous environmental
monitoring system (CEMS). During the reporting period, there is no need to
operate the standby flare and therefore no monitoring of the flare stack was
undertaken.
With reference to the emission limits shown
in Tables 3.2, 3.3 and 3.4, the hourly average concentrations and
the number of exceedances of the concerned air emissions monitored for the
CAPCS, CHP and ASP during this reporting period are presented in Tables 4.1
to 4.5.
It should be noted that measurements
recorded under abnormal operating conditions, e.g. start up and stopping of
stacks, unstable operation, test runs and interference of sensor, are disregarded.
Table 4.1 Hourly
Average of Parameters Recorded for CAPCS
|
Parameter
|
Range
of Hourly Average Conc. (mg/Nm3)
|
Emission
Limit (mg/Nm3)
|
Exceedance
Identified
|
Remarks
|
|
VOCs (including methane)
|
13.61
– 23.80
|
680
|
Nil
|
Nil
|
|
Dust
(or TSP)
|
0
– 0
|
6
|
Nil
|
Nil
|
|
Odour (including
NH3 & H2S) (a)
|
0.66
– 179.61
|
220
|
Nil
|
Nil
|
|
Note:
(a) The
odour unit is OU/Nm3.
|
Table 4.2 Hourly
Average of Parameters Recorded for CHP 1
|
Parameter
|
Range of Hourly Average
Conc. (mg/Nm3) (a)
|
Max. Emission Limit (mg/Nm3)
|
Exceedance
Identified
|
Remarks
|
|
Dust (or TSP)
|
0 – 2
|
15
|
Nil
|
Nil
|
|
Carbon Monoxide
|
0 – 545
|
650
|
Nil
|
Nil
|
|
NOx
|
0 – 344
|
300
|
Identified (d)
|
System unstable (e.g. low efficiency, unstable column
temperature )
|
|
SO2
|
0 – 151
|
50
|
Identified (e)
|
Desulpurisation system tripped and resumed to normal
after urgent maintenance.
|
|
NMVOCs (b)
|
Nil
|
150
|
-
|
Nil
|
|
VOCs (including methane) (c)
|
0 – 1,033
|
1,500
|
Nil
|
Nil
|
|
HCl
|
0 – 2
|
10
|
Nil
|
Nil
|
|
HF
|
0 – 1
|
1
|
Nil
|
Nil
|
|
Notes:
(a) All
values refer to an oxygen content in the exhaust gas of 6%
and dry basis.
(b) No
sampling was undertaken at CHP 1 as biogas production rate could not sustain
the operation of the CHP stack for the scheduled sampling on 8 February 2021.
(c) The
VOCs emission limit include methane as biogas is adopted as fuel in the
combustion process.
(d) Dates
with exceedances on NOx (number of exceedances on the day) were
identified on 15 (1) and 22 (2) April 2021.
(e) Dates
with exceedances on SO2 (number of exceedances on the day) were
identified on 21 (2), 22 (3) and 30 (4) April 2021.
|
Table
4.3 Hourly
Average of Parameters Recorded for CHP 2
|
Parameter
|
Range
of Hourly Average Conc. (mg/Nm3) (a) (b)
|
Max.
Emission Limit (mg/Nm3)
|
Exceedance
Identified
|
Remarks
|
|
Dust
(or TSP)
|
0
– 2
|
15
|
Nil
|
Nil
|
|
Carbon
Monoxide
|
0
– 323
|
650
|
Nil
|
Nil
|
|
NOx
|
0
– 414
|
300
|
Identified
(d)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
SO2
|
0
– 160
|
50
|
Identified
(e)
|
Desulpurisation
system tripped and resumed to normal after urgent maintenance.
|
|
NMVOCs (b)
|
6.0
|
150
|
Nil
|
Nil
|
|
VOCs (including methane) (c)
|
0
– 953
|
1,500
|
Nil
|
Nil
|
|
HCl
|
0
– 0
|
10
|
Nil
|
Nil
|
|
HF
|
0
– 1
|
1
|
Nil
|
Nil
|
|
Notes:
(a) All
values refer to an oxygen content in the exhaust gas of 6%
and dry basis.
(b) Bi-annual
sampling of NMVOCs was conducted in CHP 2 on 8 February 2021. No exceedance
was identified.
(c) The
VOCs emission limit include methane as biogas is adopted as fuel in the
combustion process.
(d) Dates
with exceedances on NOx (number of exceedances on the day) were
identified on 4 (3), 6 (1) and 28 (2) April 2021.
(e) Date
with exceedances on SO2 (number of exceedances on the day) was identified
on 28 (5) April 2021.
|
Table
4.4 Hourly
Average of Parameters Recorded for CHP 3
|
Parameter
|
Range
of Hourly Average Conc. (mg/Nm3) (a)
|
Max.
Emission Limit (mg/Nm3)
|
Exceedances
Identified
|
Remarks
|
|
Dust
(or TSP)
|
0
– 5
|
15
|
Nil
|
Nil
|
|
Carbon
Monoxide
|
0
– 184
|
650
|
Nil
|
Nil
|
|
NOx
|
0
– 432
|
300
|
Identified
(d)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
SO2
|
0
– 161
|
50
|
Identified
(e)
|
Desulpurisation
system tripped and resumed to normal after urgent maintenance.
|
|
NMVOCs (b)
|
Nil
|
150
|
Nil
|
Nil
|
|
VOCs (including methane) (c)
|
0
– 2,661
|
1,500
|
Identified
(f)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
HCl
|
0
– 13
|
10
|
Identified
(g)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
HF
|
0
– 1
|
1
|
Nil
|
Nil
|
|
Notes:
(a) All
values refer to an oxygen content in the exhaust gas of 6%
and dry basis.
(b) No
sampling was undertaken at CHP 3 as biogas production rate could not sustain
the operation of the CHP stack for the scheduled sampling on 8 February 2021.
(c) The
VOCs emission limit include methane as biogas is adopted as fuel in the
combustion process.
(d) Dates
with exceedances on NOx (number of exceedances on the day) were
identified on 11 (19), 12 (7), 14 (6), 15 (10), 16 (15), 17 (11), 18 (8), 19
(1), 20 (6), 21 (13), 22 (18), 23 (7), 24 (15), 25 (3), 26 (2), 27 (3), 28
(6), 29 (9) and 30 (11) April 2021.
(e) Dates
with exceedances on SO2 (number of exceedances on the day) were
identified on 10 (1), 21 (3), 22 (3), 25 (1), 27 (7) and 28 (5) April 2021.
(f) Dates
with exceedances on VOC (number of exceedances on the day) were identified on
11 (2), 12 (1) and 25 (1) April 2021.
(g) Date
with exceedances on HCl (number of exceedances on the day) was identified on
25 (1) April 2021.
|
Table 4.5 Hourly
Average of Parameters Recorded for ASP
|
Parameter
|
Range of Hourly Average Conc. (mg/Nm3) (a)
|
Max.
Emission Limit (mg/Nm3)
|
Exceedances
Identified
|
Remarks
|
|
Dust
(or TSP)
|
0.0
– 0.0
|
5
|
Nil
|
Nil
|
|
Carbon
Monoxide
|
0
– 567
|
100
|
Identified
(c)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
NOx
|
0
– 344
|
200
|
Identified
(d)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
SO2
|
0
– 80
|
50
|
Identified
(e)
|
Desulpurisation
system tripped and resumed to normal after urgent maintenance (f);
System
unstable (e.g. low efficiency, unstable column temperature) (g).
|
|
VOCs (including methane) (b)
|
0
– 22
|
20
|
Identified
(h)
|
Nil
|
|
NH3
|
0
– 220
|
35
|
Identified
(i)
|
System
unstable (e.g. low efficiency, unstable column temperature )
|
|
HCl
|
0
– 0
|
10
|
Nil
|
Nil
|
|
HF
|
0
– 1
|
1
|
Nil
|
Nil
|
|
Notes:
(a) All
values refer to an oxygen content in the exhaust gas of 11% and dry basis.
(b) The
VOCs emission limit include methane as biogas is adopted as fuel in the
combustion process.
(c) Date
with exceedances on CO (number of exceedances on the day) was identified on 5
(2) April 2021.
(d) Dates
with exceedances on NOx (number of exceedances on the day) were
identified on 2 (2), 10 (3) and 23 (1) April 2021.
(e) Dates
with exceedances on SO2 (number of exceedances on the day) were
identified on 27 (5), 28 (2) and 30 (1) April 2021.
(f) On
27 April 2021.
(g) On
28 and 30 April 2021.
(h) Date
with exceedances on VOC (number of exceedances on the day) was identified on
5 (1) April 2021.
(i) Dates
with exceedances on NH3 (number of exceedances on the day) were 2
(1), 5 (3), 6 (1), 8 (8), 9 (9), 10 (1), 11(1), 12 (1), 13 (1), 21 (1), 23
(1), 25 (4), 26 (2), 28 (7), 29 (5) and 30 (3) April 2021.
|
5.2
Odour
No odour patrol was required to be
conducted for this reporting period.
Effluent discharge was sampled monthly
from the Effluent Storage Tank as stipulated in the operation phase discharge
licence. The results of the discharge sample is recorded in Table 4.6.
Table 4.6 Results
of the Discharge Sample
|
Parameters
|
Discharged
Effluent Concentration (mg/L)
|
Discharge
Limit (mg/L)
|
Compliance
with Discharge Limit
|
|
pH
(pH units)
|
7.53
- 7.96
|
6-10
(a)
|
Yes
|
|
Suspended
Solids (b)
|
202
|
800
|
Yes
|
|
Biochemical
Oxygen Demand (5 days, 20°) (b)
|
15
|
800
|
Yes
|
|
Chemical
Oxygen Demand (b)
|
1,080
|
2,000
|
Yes
|
|
Oil
& Grease (b)
|
<5
|
40
|
Yes
|
|
Total
Nitrogen (b)
|
71.7
|
200
|
Yes
|
|
Total
Phosphorus (b)
|
47.9
|
50
|
Yes
|
|
Surfactants
(total) (b)
|
<1.0
|
25
|
Yes
|
|
Notes:
(a) Daily
Average.
(b) Effluent
sample was collected on 14 April 2021.
|
No exceedance of
discharge limit was recorded during the reporting period.
Wastes generated from the operation of the
Project include chemical waste, wastes generated from pre-treatment process and
general refuse (). Reference has
been made to the Monthly Summary Waste Flow Table prepared by the Contractor
(see Annex E).
With reference to the relevant handling records and trip tickets of this
Project, the quantities of different types of waste generated from the
operation of the Project in the reporting month are summarised in Table 4.7.
Table 4.7 Quantities
of Waste Generated from the Operation of the Project
|
Month
/ Year
|
Chemical Waste
|
Waste Generated from
Pre-treatment Process
|
General Refuse
|
|
|
Disposal of at CWTC
|
Disposed of at Landfill (a)
|
Recycled (b)
|
Disposed of at Landfill (a)
|
Recycled (c)
|
|
April
2021
|
9,700 L
|
651.29 tonnes
|
0.00 tonnes
|
2.53 tonnes (d)
|
0.00 tonne
|
|
Notes:
(a) Waste
generated from pre-treatment process and general refuse other than chemical
waste and recyclables were disposed of at NENT Landfill by sub-contractors.
(b) Among
waste generated from pre-treatment process, 0.00 tonne of metals,
0.00 tonne of papers/ cardboard packing and
0.00 tonne of plastics were sent to recyclers for
recycling during the reporting period.
(c)
Among general refuse, 0.00 kg of metals,
0.00 kg of papers/ cardboard packing and 0.00
kg of plastics were sent to recyclers for recycling
during the reporting period.
(d) It
was assumed that four 240-litre bins filled with 80% of general refuse were
collected at each collection. The general refuse density was assumed to be
around 0.15 kg/L.
|
6
Site
Audit
6.1
Environmental Site
Audit
The monthly
inspection of the landscape and visual mitigation measures for the operation
phase of the Project on 23 April 2021 covered the operation phase environmental
site audit. Joint site inspections was conducted by representatives of the
Contractor, IEC, ER and the MT on 23 April 2021 as required
for the operation of the Project.
The audits
checked the implementation of the recommended mitigation measures for air
quality, landscape and visual, water quality, waste (land contamination) and
hazard-to-life stated in the Implementation Schedule (see Annex D).
Follow-up
actions resulting from the last site inspections were generally taken as
reported by the Contractor.
Key observations during the reporting
period are summarised as follows:
23 April 2021
·
No
particular observation during this inspection.
Other than the above observations, the
Contractor has implemented environmental mitigation measures recommended in the
approved EIA Report and EM&A Manual.
Inspection
of the landscape and visual mitigation measures for the operation phase of the
Project was performed on 23 April 2021.
It was
confirmed that the necessary landscape and visual mitigation measures during
the operation phase as summarised in Annex D were generally implemented by the Contractor.
No specific observation was found during site inspections on 23 April 2021. No
non-compliance in relation to the landscape and visual mitigation measures was
identified during the site audits in this reporting period and therefore no
further actions are required. The ET/MT will keep track of the EM&A
programme to check compliance with environmental requirements and the proper
implementation of all necessary mitigation measures.
7
Environmental
Non-conformance and Deficiencies
Non-compliance of emission limits for CHP
and ASP were recorded during the reporting period.
The Contractor has reviewed the organic
waste treatment processes (i.e. waste reception, waste pre-treatment, anaerobic
digesters, and composting processes) and found that they were operated normally
during the reporting period. The Contractor has investigated the air pollution
control system and the combustion system of the CHP and ASP and
identified the following potential causes for the exceedance.
(a)
The exceedances from CHP occurred mainly when the feedstock
quantity was at 40-60% of the optimal treatment quantity, which could hinder
the performance of the CHP to achieve optimal efficiency. Therefore, it could
not effectively remove NOx at a certain period of time which leads
to the exceedance of NOx limit at CHP stacks 1 and 2;
(b)
The exceedances of NOx, SO2, VOC and HCl
limits at CHP 3 occurred due to equipment tripping and its unstable performance;
(c)
The ASP was experiencing unstable column temperature and
malfunction of thermal destructor due to equipment tripping resulting in the
incomplete combustion of biogas and NH3. These have led to the
exceedances of CO, NOx, SO2 and NH3 in ASP.
For item (a), insufficient biogas
available for CHP has been identified as a key reason that led to the reduced
performance of the CHP, resulting in emission exceedances from the CHP. In
this reporting period, the plant has received on average around 100 to 120 tonnes
of SSOW daily, which is slightly more than received in the last reporting
period. Yet, as advised by the Contractor, it is more desirable that the plant
can receive at least 150 tonnes of SSOW daily in order to generate sufficient
biogas for the CHP to be able to operate at optimal efficiency. The Contractor
will continue to liaise with EPD (Food Waste Recycling Group) in their monthly
meeting with an aim to explore the possibility of increasing the quantity of
SSOW that can be treated daily.
For item (b), unstable performance in CHP
3 was identified on 11 April 2021, the CHP was subsequently shut down for
investigation and maintenance. The Contractor has engaged with the CHP
supplier to carry out an on-site inspection for the CHP by the supplier
representative on 12 April 2021. The CHP supplier has subsequently prepared a
protocol for the Contractor to carry out further fine-tuning. Due to the
continuous exceedance recorded in CHP 3 in late April 2021, the Contractor has
decided to avoid the use of CHP 3 in May 2021 for further maintenance.
For item (c), the exceedances of CO were found
to be due to malfunction of the thermal destructor of the ASP, which was
subsequently stopped for urgent maintenance by the Contractor on the same day.
The Contractor has established a daily communication channel with the overseas
ASP supplier, to overcome the fact that the supplier cannot travel to Hong Kong
due to travel restriction at the moment. Since January 2021, the
Contractor has engaged with the overseas ASP supplier to undertake remote
fine-tuning during normal operation of the ASP on a daily basis, focusing on
key parameters including wastewater flow rate, NH3 concentration of
wastewater, exhaust air flow rate and combustion temperature of the thermal
oxidizer. The objective is to determine the desirable operating conditions of
the ASP taking into account of the aforementioned key parameters and to devise
a standard operating procedure for ASP. In addition, the Contractor
continues to carry out maintenance measures as per the supplier’s manual. The
Contractor will also work with the overseas ASP supplier to investigate the
reasons for the occasional equipment tripping that has led to unstable column
temperature of the thermal oxidizer and, subject to their investigations,
replacement of some ASP equipment and/or increased maintenance frequency may be
proposed.
The investigation report is presented in Annex G.
No complaint was
received during the reporting period.
No summon/prosecution
was received during the reporting period. The cumulative summons/prosecution
log is shown in Annex
F.
8
Future
Key Issues
Activities to be undertaken for the coming
reporting period are:
·
Operation
of the Project.
·
Modification
of the CHP and ASP to control the air emission.
9
Conclusions
This EM&A Report presents the EM&A
programme undertaken during the reporting period from 1 to 30 April 2021
in accordance with EM&A Manual (Version F) and requirements of EP (FEP-01/395/2010/C).
For the operation phase, exceedances of
the emission limits for CAPCS, CHP and ASP stack monitoring were recorded under
normal operating conditions during the reporting period (see Table 8.1).
Table 8.1 Exceedances
for Stack Emissions
|
Stack
|
Exceedances
During the Reporting Period
|
|
Cogeneration
Unit (CHP)
|
· Exceeded
emission limit of NOx on 4, 6, 11, 12, 14 – 30 April 2021.
· Exceeded
emission limit of SO2 on 10, 21, 22, 25, 27, 28 and 30 April 2021.
· Exceeded
emission limit of VOC on 11, 12 and 25 April 2021.
· Exceeded
emission limit of HCl on 25 April 2021.
|
|
Ammonia
Stripping Plant (ASP)
|
· Exceeded
emission limit of CO on 5 April 2021.
· Exceeded
emission limit of NOx on 2, 10 and 23 April 2021.
· Exceeded
emission limit of SO2 on 27, 28 and 30 April 2021.
· Exceeded
emission limit of VOC on 5 April 2021.
· Exceeded
emission limit of NH3 on 2, 5, 6, 8, 9, 10, 11, 12, 13, 21, 23,
25, 26, 28, 29 and 30 April 2021.
|
Exceedances in emission parameters of CHP were
found to be a result of the occasional low biogas loading at the CHPs and
unstable performance of CHP 3. The exceedances of ASP were found to be result
of malfunction of its thermal destructor and the incomplete combustion of
biogas at ASP.
The Contractor has implemented mitigation
measures to control the exceedance including the continuous monitoring of CHP
and ASP to optimise overall performance.
No non-compliance to the effluent
discharge limit was recorded during this reporting period.
The environmental control /mitigation
measures related to air quality, water quality, waste (including land
contamination prevention), hazard-to-life and landscape and visual recommended
in the approved EIA Report and the EM&A Manual were properly implemented by
the Contractor during the reporting month.
Monthly landscape and visual monitoring were
conducted in the reporting period. The necessary landscape and visual
mitigation measures recommended in the approved EIA Report were generally implemented
by the Contractor.
No complaint/summon/prosecution was received.
