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 70th monthly
Environmental Monitoring and Audit (EM&A) report presenting the EM&A
works carried out during the period from 1 to 31 March 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 and SO2
from CHP 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
and ASP were found to be a result of problems with the low biogas loading at
CHP 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.
6,000 L of chemical waste was collected by
licenced waste collector from the operation of the Project.
325.21 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 3.11 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 26 March 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.
1
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 70th
EM&A report which summarises the monitoring results and audit findings for
the EM&A programme during the reporting period from 1 to 31 March 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
2
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.
|
2.4
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
|
-
|
3
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.
3.1.1
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.
4
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)
|
0 – 83.32
|
680
|
Nil
|
Nil
|
|
Dust (or TSP)
|
0 – 5.66
|
6
|
Nil
|
Nil
|
|
Odour (including NH3 & H2S) (a)
|
0 – 181.06
|
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 – 0
|
15
|
Nil
|
Nil
|
|
Carbon Monoxide
|
0 – 409
|
650
|
Nil
|
Nil
|
|
NOx
|
0 – 299
|
300
|
Nil
|
Nil
|
|
SO2
|
0 – 49
|
50
|
Nil
|
Nil
|
|
NMVOCs (b)
|
Nil
|
150
|
-
|
Nil
|
|
VOCs
(including methane) (c)
|
0 – 938
|
1,500
|
Nil
|
Nil
|
|
HCl
|
0 – 1
|
10
|
Nil
|
Nil
|
|
HF
|
0.0 – 1.0
|
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.
|
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 – 7
|
15
|
Nil
|
Nil
|
|
Carbon Monoxide
|
0 – 395
|
650
|
Nil
|
Nil
|
|
NOx
|
0 – 325
|
300
|
Identified (d)
|
Due to low biogas loading.
|
|
SO2
|
0 – 95
|
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 – 1,443
|
1,500
|
Nil
|
Nil
|
|
HCl
|
0 – 5
|
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 2 (3), 9 (1), 10 (1),
13 (1), 15 (8), 16 (5), 18 (5), 19 (8), 20 (2), 21 (6), 22 (4), 23 (2), 25
(2) and 26 (6) March 2021.
(e)
Dates with exceedances on SO2
(number of exceedances on the day) were identified on 15 (2) and 25 (4) March
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 – 0
|
15
|
Nil
|
Nil
|
|
Carbon Monoxide
|
0 – 0
|
650
|
Nil
|
Nil
|
|
NOx
|
0 – 0
|
300
|
Nil
|
Nil
|
|
SO2
|
0 – 0
|
50
|
Nil
|
Nil
|
|
NMVOCs (b)
|
Nil
|
150
|
Nil
|
Nil
|
|
VOCs (including
methane) (c)
|
0 – 0
|
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)
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.
|
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 – 22
|
100
|
Nil
|
Nil
|
|
NOx
|
0 – 200
|
200
|
Nil
|
Nil
|
|
SO2
|
0 – 45
|
50
|
Nil
|
Nil
|
|
VOCs (including
methane) (b)
|
0 – 5
|
20
|
Nil
|
Nil
|
|
NH3
|
0 – 127
|
35
|
Identified (c)
|
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)
Dates with exceedances on NH3 (number
of exceedances on the day) were identified on 2 (2), 3 (2), 7 (2), 27 (1) and
28 (2) March 2021.
|
4.2
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)
|
7.33 - 7.99
|
6-10 (a)
|
Yes
|
|
Suspended Solids (b)
|
79
|
800
|
Yes
|
|
Biochemical Oxygen Demand (5 days, 20°) (b)
|
21
|
800
|
Yes
|
|
Chemical Oxygen Demand (b)
|
630
|
2,000
|
Yes
|
|
Oil & Grease (b)
|
<5
|
40
|
Yes
|
|
Total Nitrogen (b)
|
70.8
|
200
|
Yes
|
|
Total Phosphorus (b)
|
38.9
|
50
|
Yes
|
|
Surfactants (total) (b)
|
<1.0
|
25
|
Yes
|
|
Notes:
(a)
Daily Average.
(b)
Effluent sample was collected on 10 March 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)
|
|
March 2021
|
6,000 L
|
325.21 tonnes
|
0.00 tonnes
|
3.11 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.
|
5
Site Audit
5.1
Environmental Site Audit
The monthly inspection of the landscape and
visual mitigation measures for the operation phase of the Project on 26 March 2021
covered the operation phase environmental site audit. Joint site inspections was
conducted by representatives of the Contractor, IEC, ER and the MT on 26 March 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:
26 March 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 26 March 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 26 March 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.
6
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 and SO2 at a certain period of
time which leads to the exceedance of NOx and SO2 limit at
CHP stacks;
(b)
The ASP was
experiencing unstable column temperature due to equipment tripping resulting in
the incomplete combustion of biogas and NH3. This leads to the
exceedances of 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. Currently, the plant is receiving on average around 100 tonnes
of SSOW daily. 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. In addition, on-site adjustment
was completed in January 2021. The Contractor has engaged with the CHP
supplier to undertake remote fine-tuning during normal operation of the CHP, an
on-site inspection was carried out by the CHP supplier representative on 12
March 2021.
For item (b), improvement
has been observed in ASP emission performance with a reduction of no. of hours
of exceedance compared with last reporting period, from 55 in February to 9 in
March 2021. The Contractor has started to establish 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. The ASP supplier is preparing a guideline based on the data collected
from January to March 2021 for the Contractor to improve the ASP performance. 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.
7
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.
8
Conclusions
This EM&A
Report presents the EM&A programme undertaken during the reporting period
from 1 to 31 March 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 2,
9, 10, 13, 15, 16, 18, 19, 20, 21, 22, 23, 25 and 26 March 2021.
·
Exceeded emission limit of SO2 on 15
and 25 March 2021.
|
|
Ammonia Stripping Plant (ASP)
|
·
Exceeded emission limit of NH3 on 2,
3, 7, 27 and 28 March 2021.
|
Exceedances in
emission parameters of CHP and ASP were found to be a result of the occasional low
biogas loading at CHP 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.
