*Annex A*	*Location of Project*
*Annex B*	*Project Organisation Chart and Contact Detail*
*Annex C*	*Calibration Certification for the On-line Stack Monitoring System*
*Annex D*	*Implementation Schedule of Mitigation Measures*
*Annex E*	*Waste Flow Table*
*Annex F*	*Environmental complaint, Environmental Summons and Prosecution Log*
*Annex G*	*Investigation Report*

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 72nd monthly Environmental Monitoring and Audit (EM&A) report presenting the EM&A works carried out during the period from 1 to 31 May 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 and VOC from CHP and CO, NOx, VOC 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 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.

4,000 L of chemical waste was collected by licenced waste collector from the operation of the Project.

671.03 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 2.76 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 21 May 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.

1.1 Purpose of the Report

This is the 72nd EM&A report which summarises the monitoring results and audit findings for the EM&A programme during the reporting period from 1 to 31 May 2021.

1.2 Structure of the Report

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

2.1 Background

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 ([1]). The construction phase EM&A programme was completed in the end of February 2020.

2.2 General Site Description

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.

2.3 Major Activities Undertaken

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.

2.5 Status of Environmental Approval Documents

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

3.1 Environmental Monitoring

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.

3.1.2 Odour

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([3]).

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.

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.

3.2 Site Audit

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.

3.2.1 Water Quality

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.

3.2.2 Landscape and Visual

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

4.1 Air Quality

4.1.1 Commissioning Phase Monitoring

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.

4.1.2 Operation Phase Monitoring

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)	11.21 – 16.98	680	Nil	Nil
Dust (or TSP)	0.00 – 0.43	6	Nil	Nil
Odour (including NH3 & H2S) (a)	0.00 – 180.06	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 – 1	15	Nil	Nil
Carbon Monoxide	0 – 431	650	Nil	Nil
NOx	0 – 354	300	Identified (d)	System unstable (e.g. low efficiency, unstable column temperature )
SO2	0 – 145	50	Identified (e)	Desulpurisation system tripped and resumed to normal after urgent maintenance.
NMVOCs (b)	Nil	150	-	Nil
VOCs (including methane) (c)	0 – 890	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 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 6 (2), 11 (2), 12 (11), 13 (7) and 18 (2) May 2021. (e) Dates with exceedances on SO2 (number of exceedances on the day) were identified on 21 (7) and 26 (4) May 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 – 4	15	Nil	Nil
Carbon Monoxide	0 – 288	650	Nil	Nil
NOx	0 – 298	300	Nil	Nil
SO2	0 – 51	50	Identified (d)	Desulpurisation system tripped and resumed to normal after urgent maintenance.
NMVOCs (b)	6.0	150	Nil	Nil
VOCs (including methane) (c)	0 – 1,441	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) 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) Date with exceedances on SO2 (number of exceedances on the day) was identified on 7 (1) May 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 – 4	15	Nil	Nil
Carbon Monoxide	0 – 225	650	Nil	Nil
NOx	0 – 438	300	Identified (d)	System unstable (e.g. low efficiency, unstable column temperature )
SO2	0 – 139	50	Identified (e)	Desulpurisation system tripped and resumed to normal after urgent maintenance.
NMVOCs (b)	Nil	150	Nil	Nil
VOCs (including methane) (c)	0 – 1,591	1,500	Identified (f)	System unstable (e.g. low efficiency, unstable column temperature )
HCl	0 – 3	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. (d) Dates with exceedances on NOx (number of exceedances on the day) were identified on 1 (17), 2 (17), 3 (3), 4 (10), 5 (13), 6 (3), 17 (3), 18 (7), 20 (1), 21 (10), 22 (15), 23 (17), 24 (12), 25 (7) and 26 (8) May 2021. (e) Dates with exceedances on SO2 (number of exceedances on the day) were identified on 21 (7) and 26 (4) May 2021. (f) Dates with exceedances on VOC (number of exceedances on the day) were identified on 18 (1), 22 (1) and 26 (1) May 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 – 1,278	100	Identified (c)	System instability due to unstable column temperature.
NOx	0 – 233	200	Identified (d)	System instability due to unstable column temperature.
SO2	0 – 47	50	Nil	Nil
VOCs (including methane) (b)	0 – 118	20	Identified (e)	System instability due to unstable column temperature.
NH3	0 – 234	35	Identified (f)	System instability due to 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 7 (2) May 2021. (d) Dates with exceedances on NOx (number of exceedances on the day) were identified on 5 (1) May 2021. (e) Dates with exceedances on VOC (number of exceedances on the day) was identified on 7 (2) May 2021. (f) Date with exceedances on NH3 (number of exceedances on the day) were identified on 1 (2), 2 (3), 4 (13), 5 (7), 6 (1), 7 (4), 8 (4), 9 (6), 11 (1), 15 (1), 20 (5), 21 (12), 23 (1) and 26 (2) May 2021.

4.2 Odour

4.2.1 Operation Phase Monitoring

No odour patrol was required to be conducted for this reporting period.

4.3 Water Quality

4.3.1 Operation Phase Monitoring

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)	7.61 - 8.23	6-10 (a)	Yes
Suspended Solids (b)	183	800	Yes
Biochemical Oxygen Demand (5 days, 20°) (b)	17	800	Yes
Chemical Oxygen Demand (b)	1,070	2,000	Yes
Oil & Grease (b)	<5	40	Yes
Total Nitrogen (b)	84.0	200	Yes
Total Phosphorus (b)	37.5	50	Yes
Surfactants (total) (b)	<1.0	25	Yes
Notes: (a) Daily Average. (b) Effluent sample was collected on 13 May 2021.

No exceedance of discharge limit was recorded during the reporting period.

4.4 Waste Management

4.4.1 Operation Phase Monitoring

Wastes generated from the operation of the Project include chemical waste, wastes generated from pre-treatment process and general refuse ([4]). 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)
May 2021	4,000 L	671.03 tonnes	0.00 tonnes	2.76 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

5.1.1 Operation Phase

The monthly inspection for the operation phase of the Project on 21 May 2021 covered the operation phase environmental site audit. Joint site inspections was conducted by representatives of the Contractor, IEC, and the MT on 21 May 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:

21 May 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.

5.2 Landscape and Visual Audit

The monthly inspection for the operation phase of the Project on 21 May 2021 also covered the monitoring of landscape and visual mitigation measures, for the operation phase of the Project.

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 21 May 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

6.1 Summary of Environmental Non-Compliance 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 1 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 the CHP;

(b) The exceedances of NOx and VOC limits at CHP 3 occurred due to equipment tripping and its unstable performance;

(d) The ASP was experiencing unstable column temperature due to equipment tripping resulting in the incomplete combustion of biogas and NH3. These have led to the exceedances of CO, NOx, VOC and NH3 in ASP.

For item (a), insufficient biogas available for CHP 1 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 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 of the CHP 3 has led to exceedances of NOx and VOC. Although the Contractor was advised to halt the use of CHP 3 in this reporting period due to its unstable performance, it was used when CHP 2 was under urgent maintenance for about 10 days as sufficient biogas consumption requires the operation of 2 CHPs. The Contractor will continue to avoid the use of CHP 3 and engage with the supplier to carry out on-site inspection of the CHP.

For item (c), The SO2 exceedances recorded in CHPs were due to tripping of the desulphurisation system, which were stopped temporary for urgent maintenance. The desulphurisation system resumed to normal operation on the day after urgent maintenance.

For item (d), the exceedances of CO, NOx, VOC and NH3 were found to be due to unstable column temperature in biogas combustion, which have led to incomplete combustion of biogas and NH3 and hence exceedances in ASP. 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 continue to 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.

6.2 Summary of Environmental Complaint

No complaint was received during the reporting period.

6.3 Summary of Environmental Summon and Successful Prosecution

No summon/prosecution was received during the reporting period. The cumulative summons/prosecution log is shown in Annex F.

7 Future Key Issues

7.1 Key Issues for the Coming Month

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 May 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 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 1 - 6, 11, 12, 13, 17, 18, 20, 21, 22, 23, 24, 25 and 26 May 2021. · Exceeded emission limit of SO2 on 7, 21 and 26 May 2021. · Exceeded emission limit of VOC on 18, 22 and 26 May 2021.
Ammonia Stripping Plant (ASP)	· Exceeded emission limit of CO on 7 May 2021. · Exceeded emission limit of NOx on 5 May 2021. · Exceeded emission limit of VOC on 7 May 2021. · Exceeded emission limit of NH3 on 1, 2, 4, 5, 6, 7, 8, 9, 11, 15, 20, 21, 23 and 26 May 2021.

Stack

Exceedances During the Reporting Period

Cogeneration Unit (CHP)

· Exceeded emission limit of NOx on 1 - 6, 11, 12, 13, 17, 18, 20, 21, 22, 23, 24, 25 and 26 May 2021.

· Exceeded emission limit of SO2 on 7, 21 and 26 May 2021.

· Exceeded emission limit of VOC on 18, 22 and 26 May 2021.

Ammonia Stripping Plant (ASP)

· Exceeded emission limit of CO on 7 May 2021.

· Exceeded emission limit of NOx on 5 May 2021.

· Exceeded emission limit of VOC on 7 May 2021.

· Exceeded emission limit of NH3 on 1, 2, 4, 5, 6, 7, 8, 9, 11, 15, 20, 21, 23 and 26 May 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 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.

([1]) As some of the minor items are yet to be closed out in March 2019, the construction phase EM&A programme and Operation Phase EM&A programme were undertaking in parallel in March 2019.

([2]) A standby facility. Only operate when the CHPs are not in operation or when the biogas generated exceeded the utilisation rate of the CHPs.

([3]) The odour patrol route was changed during this reporting period to include sampling points that are frequently visited by visitors and eliminate sampling points that are not visited by visitors.

([4]) Public fill and construction waste may only be generated during maintenance works when there are civil or structural works.