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 118^th Monthly Environmental Monitoring and Audit (EM&A) report presenting the EM&A works carried out during the period from 1 to 31 March 2025 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, 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

· Cleaning of combustion chamber of CHP2.

Environmental monitoring and audit progress

air Quality monitoring

Non-compliance of emission limits of NOx and HCl from CHP1; NOx from CHP3; NOx, SO2, NH3 and HCl from the ASP; and HF from the Standby Gas Flaring Unit were recorded during the reporting period.

Water Quality

Discharge sample from the outlet chamber of the Effluent Storage tank was collected on 26 March 2025, but the laboratory reports and results remained pending as at the date of the March 2025 EM&A report submission, and will be presented in the subsequent report.

Samples from Petrol Interceptor 1 and 2 were collected on 19 February 2025 and 27 February 2025 respectively, but the laboratory reports and results remained pending as at the date of the February 2025 EM&A report submission. Having received the relevant laboratory report, these results are now presented in this EM&A report.

Waste Management

Waste generated from the operation of the Project includes chemical waste, waste generated from pre-treatment process, and general refuse.

34,800 litres of chemical waste were disposed of at CWTC in March 2025.

548.97 tonnes of waste generated from pre-treatment process from the operation of the Project were disposed of at landfill. Among the waste generated from pre-treatment process from the operation of the Project, 0.000 tonnes of metals, 0.000 tonnes of papers/cardboard packing and 0.000 tonnes of plastics were sent to recyclers for recycling during the reporting period.

Around 2.995 tonnes of general refuse from the operation of the Project were disposed of at landfill. Among the general refuse from the operation of the Project, 0.001 tonnes of metals, 0.027 tonnes of papers/cardboard packing and 0.003 tonnes 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 inspection was carried out by the representatives of the Contractor and the Monitoring Team (MT). The Independent Environmental Checker (IEC) was also present at the joint inspection on 26 March 2025.

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, complaint, summons and prosecution

Exceedances of the air emission limits for CHPs, ASP and Standby Gas Flaring Unit were recorded during the reporting period.

No complaint was received during the reporting period.

future key issues

Activities to be undertaken in the next reporting month include:

· Implementation of various optimization measures in WWTP.

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 118^th 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 2025.

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 construction phase EM&A programme was completed in the end of February 2020. The operation phase of the EM&A programme commenced on 1 March 2019[1].

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 an average of 84.09 tonnes and treated an average of 66.38 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 de-sulphurisation, the CHPs, the ASP, and the biological wastewater treatment plant (84.09 t/d SSOW received); and · Cleaning of combustion chamber of CHP2.

Activities Undertaken in the Reporting Period

· Systems being operated – waste reception, pre-treatment, CAPCS extraction, the digesters, the centrifuge, the composting tunnels, the de-sulphurisation, the CHPs, the ASP, and the biological wastewater treatment plant (84.09 t/d SSOW received); and

· Cleaning of combustion chamber of CHP2.

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 Licence	WT00038391-2021	7 July 2021 – 30 June 2026	Approved on 7 July 2021
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 is 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 (CHPs) and the ammonia stripping plant (ASP) during the commissioning and operation phase. The most recent sensor calibration for the CAPCS system for VOCs and H₂S were both carried out in January 2025. The most recent span calibrations for the CEMS systems (CHP1, CHP2, CHP3, and ASP) were carried out on 28 May 2024. Annual CAPCS calibration was carried out on 15 and 30 October 2024.

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 (NO_x)	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	· ASP
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
NO_x	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). The monitoring of NMVOCs ended in August 2021. (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
NO_x	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 by Person-in-charge of Odour Monitoring:	Action by 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 weeks; 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 C. 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. As stipulated in the operation phase discharge licence, effluent discharge is to be sampled monthly from the outlet chamber of the Effluent Storage Tank, while effluent discharge is to be sampled bi-monthly from the Petrol Interceptors. The effluent quality shall meet the discharge limits as described in Table 3.9 and Table 3.10.

Table 3.9 Discharge Limits for Effluent from the Outlet Chamber of the Effluent Storage Tank

Parameter	Discharge Limit (mg/L)
Flow Rate (m³/day)^(a)	645
pH (pH units)^(b)	6-10 ^(c)
Suspended Solids^(b)	800
Biochemical Oxygen Demand (5 days, 20°)^(b)	800
Chemical Oxygen Demand^(b)	2,000
Oil & Grease^(b)	40
Total Nitrogen^(b)	200
Total Phosphorus^(b)	50
Surfactants (total)^(b)	25
Notes: (a) Flow rate is not a parameter required to be monitored and reported by the Contractor in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (b) Parameters required to be monitored and reported by the Contractor in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (c) Range.

Table 3.10 Discharge Limits for Effluent from the Petrol Interceptors

Parameter	Discharge Limit (mg/L)
Flow Rate (m³/day)	245 ^(a)
Suspended Solids^(b)	30
Chemical Oxygen Demand^(c)	80
Oil & Grease^(c)	20
Surfactants (total)^(b)	15
(a) The surface runoff flow rate limit was estimated by the overall yearly rainfall data. As the actual flowrate from the petrol interceptors depends on the weather condition instead of the performance of the petrol interceptor, monitoring and reporting of this parameter is not required. Hence this parameter is not reported in the relevant Water Quality results tables in Section 4 below. (b) Parameter not required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (c) Parameters required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO.

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 C), 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 OPERATION PHASE MONITORING

The concentrations of concerned air pollutants emitted from the stacks of the CAPCS, CHPs, ASP, and the Standby Flaring Gas Unit during the reporting period are monitored on-line by the continuous environmental monitoring system (CEMS). The Standby Flaring Gas Unit was operational on 16 March 2025 from 8:00-18:00 and on 26 March 2025 from 11:00-12:00.

With reference to the emission limits shown in Tables 3.2, 3.3, 3.4, and 3.5, the hourly average concentrations and the number of exceedances of the concerned air emissions monitored for the CAPCS, CHPs, ASP and the Standby Flaring Gas Unit during the reporting period are presented in Tables 4.1 to 4.6.

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) ^(a)	0 – 1	680	Nil	Nil
Dust (or TSP)	0 – 0	6	Nil	Nil
Odour (including NH₃ & H₂S) ^(b)	0 – 10	220	Nil	Nil
Notes: (a) The VOCs emission limit includes methane as biogas is adopted, as fuel in the combustion process. The odour unit is ou/Nm³. (b)

Table 4.2 Hourly Average of Parameters Recorded for CHP 1

Parameter	Range of Hourly Average Conc. (mg/Nm³)^(a)	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 – 7	15	Nil	Nil
Carbon Monoxide	0 – 650	650	Nil	Nil
NO_x	0 – 506	300	Identified ^(c)	System unstable (e.g. low efficiency)
SO₂	0 – 45	50	Nil	Nil
VOCs (including methane) ^(b)	0 – 997	1,500	Nil	Nil
HCl	0 – 82	10	Identified ^(d)	System unstable (e.g. low efficiency)
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) The VOCs emission limit include methane as biogas is adopted as fuel in the combustion process. (c) Dates with NO_x exceedances (number of exceedances on that day) were identified on 14(5), 15(5), 16(6), 17(1), 18(9), 19(21), 20(24), 21(15), 24(10), 25(10) and 26(16) March 2025. (d) Date with HCl exceedance (number of exceedance on that day) was identified on 16(1) March 2025.

Table 4.3 Hourly Average of Parameters Recorded for CHP 2

Parameter	Range of Hourly Average Conc. (mg/Nm³) ^(a)	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 – 9	15	Nil	Nil
Carbon Monoxide	0 – 552	650	Nil	Nil
NO_x	0 – 279	300	Nil	Nil
SO₂	0 – 11	50	Nil	Nil
VOCs (including methane) ^(b)	0 – 370	1,500	Nil	Nil
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) The VOCs emission limit include methane as biogas is adopted as fuel in the combustion process.

Table 4.4 Hourly Average of Parameters Recorded for CHP 3

Parameter	Range of Hourly Average Conc. (mg/Nm³) ^(a)	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 – 5	15	Nil	Nil
Carbon Monoxide	0 – 140	650	Nil	Nil
NO_x	0 – 509	300	Identified ^(c)	System unstable (e.g. low efficiency)
SO₂	0 – 48	50	Nil	Nil
VOCs (including methane) ^(b)	0 – 321	1,500	Nil	Nil
HCl	0 – 8	10	Nil	Nil
HF	0 – 0	1	Nil	Nil
Notes: (a) All values refer to an oxygen content in the exhaust gas of 6% and dry basis. (b) The VOCs emission limit include methane as biogas is adopted as fuel in the combustion process. (c) Dates with NO_x exceedances (number of exceedances on that day) were identified on 1(4), 2(1), 4(2), 5(4), 6(5), 7(3), 8(1), 9(5), 11(1), 12(6), 13(17), 14(3), 16(2), 17(14), 18(13), 21(4), 22(6), 23(11), 24(3), 25(1), 27(8), 28(6), 29(8), 30(16) and 31(16) March 2025.

Table 4.5 Hourly Average of Parameters Recorded for ASP

Parameter	Range of Hourly Average Conc. (mg/Nm³) ^(a)	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 – 5	5	Nil	Nil
Carbon Monoxide	0 – 99	100	Nil	Nil
NO_x	0 – 1,133	200	Identified ^(c)	System unstable (e.g. low efficiency), Equipment Tripped (Stopped and Restarted) and Normal Equipment Start-up Process / stopping Process (1-3hr)
SO₂	0 – 79	50	Identified ^(d)	System unstable (e.g. low efficiency)
VOCs (including methane) ^(b)	0 – 18	20	Nil	Nil
NH₃	0 – 149	35	Identified ^(e)	System unstable (e.g. low efficiency)
HCl	0 – 12	10	Identified ^(f)	System unstable (e.g. low efficiency)
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) The VOCs emission limit include methane as biogas is adopted as fuel in the combustion process. (c) Dates with NO_x exceedances (number of exceedances on that day) were identified on 1(21), 2(17), 3(20), 4(16), 5(23), 6(13), 7(22), 8(24), 9(10), 10(10), 11(16), 12(5), 21(2), 22(12), 23(15), 24(13), 25(8), 26(12), 27(16), 28(22), 29(22), 30(20) and 31(13) March 2025. (d) Dates with SO2 exceedances (number of exceedances on that day) were identified on 25(1) and 26(1) March 2025. (e) Dates with NH3 exceedances (number of exceedances on that day) were identified on 1(4), 2(1), 3(2), 5(1), 9(1), 10(2), 11(6), 12(1), 23(10), 24(7), 25(4), 27(3), 28(3) and 29(1) March 2025. (f) Date with HCl exceedance (number of exceedance on that day) was identified on 25(1) March 2025.

Table 4.6 Hourly Average of Parameters Recorded for the Standby Flaring Gas Unit

Parameter	Range of Hourly Average Conc. (mg/Nm³) ^{(a) (c)}	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 - 0	5	Nil	Nil
Carbon Monoxide	0 - 12	100	Nil	Nil
NO_x	0 - 97	200	Nil	Nil
SO₂	0 - 39	50	Nil	Nil
VOCs (including methane) ^(b)	0 - 10	20	Nil	Nil
HCl	0 - 0	10	Nil	Nil
HF	0 - 5	1	Identified ^(c)	Normal Equipment Start-up Process / stopping Process (1-3hr)
Notes: (a) All values refer to an oxygen content in the exhaust gas of 6% and dry basis. (b) The VOCs emission limit include methane as biogas is adopted as fuel in the combustion process. (c) Dates with HF exceedances (number of exceedances on that day) were identified on 16(4) and 26(1) March 2025.

4.2 odour

4.2.1 OPERATION PHASE MONITORING

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

4.2.2 water quality

4.2.3 OPERATION PHASE MONITORING

Effluent discharge is sampled from the outlet chamber of the Effluent Storage Tank monthly and from the Petrol Interceptor(s) bi-monthly as stipulated in the operation phase discharge licence. The results of the discharge samples from the outlet chamber of the Effluent Storage Tank are recorded in Table 4.7 and the results from the Petrol Interceptor samples are recorded in Tables 4.8 – 4.9.

Discharge sample from the outlet chamber of the Effluent Storage tank was collected on 26 March 2025, but the laboratory report and result remain pending as at the date of the March 2025 EM&A report submission, and will be presented in the subsequent report.

Sample from Petrol Interceptor 1 and 2 were collected on 19 February 2025 and 27 February 2025 respectively, but the laboratory reports and results remain pending as at the date of the February 2025 EM&A report submission, and is now presented having received the laboratory report.

Petrol Interceptor Sampling was not required during March 2025.

Table 4.7 Results of the Discharge Sample from the Outlet Chamber of the Effluent Storage Tank (March 2025)

Parameter	Discharged Effluent Concentration (mg/L)	Discharge Limit (mg/L)	Compliance with Discharge Limit
Flow Rate (m³/day)^(a)	Pending ^{(e) (f)}	645	Pending
pH (pH units)^(b)	Pending ^(e)	6 - 10^(c)	Pending
Suspended Solids ^{(b) (d)}	Pending ^(d)	800	Pending
Biochemical Oxygen Demand (5 days, 20°) ^{(b) (d)}	Pending ^(d)	800	Pending
Chemical Oxygen Demand ^{(b) (d)}	Pending ^(d)	2,000	Pending
Oil & Grease ^{(b) (d)}	Pending ^(d)	40	Pending
Total Nitrogen ^{(b) (d)}	Pending ^(d)	200	Pending
Total Phosphorus ^{(b) (d)}	Pending ^(d)	50	Pending
Surfactants (total)^{(b) (d)}	Pending ^(d)	25	Pending
Notes: (a) Parameter not required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (b) Parameters required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (c) Daily Range. (d) Sample collected on 26 March 2025; data was pending as at the date of the March 2025 EM&A report and will be presented in the subsequent report. (e) Data collected daily. (f) Maximum daily volume of wastewater discharged during the month.

Table 4.8 Results of the Discharge Sample from the Petrol Interceptor 1 (February 2025)

Parameter	Discharged Effluent Concentration (mg/L)	Discharge Limit (mg/L)	Compliance with Discharge Limit
Suspended Solids^(b)	<2 ^(a)	30	Yes
Chemical Oxygen Demand ^(c)	8 ^(a)	80	Yes
Oil & Grease ^(c)	<5 ^(a)	20	Yes
Surfactants (total)^(b)	<1.0 ^(a)	15	Yes
Notes: (a) Sample collected on 19 February 2025; data remained pending as at the date of the February 2025 EM&A report submission. Having received the relevant laboratory report, these results are now presented in this EM&A report. (b) Parameter not required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (c) Parameters required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO.

Table 4.9 Results of the Discharge Sample from the Petrol Interceptor 2 (February 2025)

Parameter	Discharged Effluent Concentration (mg/L)	Discharge Limit (mg/L)	Compliance with Discharge Limit
Suspended Solids^(b)	9 ^(a)	30	Yes
Chemical Oxygen Demand ^(c)	13 ^(a)	80	Yes
Oil & Grease ^(c)	<5 ^(a)	20	Yes
Surfactants (total)^(b)	<1.0 ^(a)	15	Yes
Notes: (a) Sample collected on 27 February 2025; data remained pending as at the date of the February 2025 EM&A report submission. Having received the relevant laboratory report, these results are now presented in this EM&A report. (b) Parameter not required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO. (c) Parameters required to be reported in accordance with Section B2 of the Effluent Discharge Licence under the WPCO.

4.3 waste management

4.3.1 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 D). 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 4.10.

Table 4.10 Quantities of Waste Generated from the Operation of the Project

Month / Year	Chemical Waste	Waste Generated from Pre-treatment Process		General Refuse
Month / Year	Disposed of at CWTC	Disposed of at Landfill ^(a)	Recycled ^(b)	Disposed of at Landfill ^(a)	Recycled ^(c)
March 2025	34,800 L ^(d)	548.97 tonnes	0.000 tonnes	2.995 tonnes^(e)	0.031 tonnes
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, 0.000 tonnes of metals, 0.000 tonnes of papers/cardboard packing and 0.000 tonnes of plastics were sent to recyclers for recycling during the reporting period. (c) Among general refuse, 0.001 tonnes of metals, 0.027 tonnes of papers/cardboard packing and 0.003 tonnes of plastics were sent to recyclers for recycling during the reporting period. (d) 34,800 L of chemical waste (30,000 L of unwanted flocculation agent and 4,800 L of spent activated carbon) were disposed of at CWTC during the reporting period. (e) 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 26 March 2025 covered the operation phase environmental site audit. Joint site inspection was conducted by representatives of the Contractor, IEC, and the MT 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 C).

Key observations during the reporting period are summarised as follows:

26 March 2025

· No particular observation during this inspection.

The Contractor has implemented the environmental mitigation measures recommended in the approved EIA Report and EM&A Manual.

5.2 landscape and audit

Inspection of the landscape and visual mitigation measures for the operation phase of the Project was performed on 26 March 2025.

It was confirmed that the necessary landscape and visual mitigation measures during the operation phase as summarised in Annex C were generally implemented by the Contractor. No specific observation was found during the joint site inspection on 26 March 2025. 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 of NO_x and HCl from CHP1; NO_x from CHP3; NO_x, SO_2,NH₃ and HCl from the ASP; and HF from the Standby Gas Flaring Unit 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 de-sulphurisation system, the CHPs, and the ASP; the potential causes for the exceedance were identified.

The investigation reports of the above exceedances are presented in Annex F.

An overview of the various measures/ actions to be taken by the Contractor to address any exceedances is summarised in Table 6.1.

Table 6.1 Implementation of Measures/ Actions to Address any Exceedances

Monitoring Location	Measures/ Actions to Address any Exceedances	Implementation Timeline & Status
Centralised Air Pollution Unit (CAPCS)	· To address the exceedances for Total Odour (ou/Nm³) recorded in January 2024 and February 2025, the Contractor ordered a new H₂S / ORP sensor to replace the faulty one which was installed on 23 May 2024. · The cleaning of the ventilation pumps was conducted in April 2024. · The Contractor further identified that the ongoing exceedances for Dust, Total Odour, and VOCs from August 2024 – January 2025 were caused by chemical pipeline leakage, sensor issues, and the inefficiency of the chemical scrubber. · Fine-tuning measures and adjustment in the operation of the system were implemented in October 2024. · An enclosure has been set up to protect the VOC and H₂S sensors, and an ozone deodorization unit has been installed as of November 2024. An air sample was also taken to compare the sensor data.	· The Contractor has confined the leakage in the chemical pipeline and cleaned the chemical scrubber no.1. The chemical pipeline is back to service and there was no leakage now.
Cogeneration Unit 1 (CHP 1)	· To address the ongoing NO_x exceedances recorded from October 2023 – March 2025, the Contractor ordered 3 new cylinder heads from the supplier to replace the old ones and improve performance which were installed in May 2024. · To address the SO₂ exceedances recorded from October 2023 – June 2024, August 2024, and November – December 2024, SO₂ sampling and testing was completed by a third-party laboratory that showed lower SO₂ values than those reported by the CEMS. The lower values measured by the laboratory was attributed to methane gas interference. Based on this study, it was proposed to implement a correction factor in the CEMS to adjust for the methane gas interference. After review by MT and IEC, the correction factor was implemented in May 2024. · The Contractor received additional training for operation of the CHPs during December 2024. · The fine-tuning measures were implemented during May 2024, and a further tuning was carried out on 12 August 2024. · To address the HCl exceedances recorded from October 2023 – April 2024, July 2024, September – October 2024, and January 2025 and March 2025, the Contractor implemented in May 2024 fine tuning measures such as reviewing the ignition temperature curve, spark plug condition check and adjusting the intake & exhaust valves on the cylinder to reduce the fluctuations in HCl emissions and keep within the permissible limit. · A CHP expert from Europe visited the ORRC1 facility in August 2024 to review the performance of the CHPs and recommended various spare parts be replaced. · The Contractor will receive additional advanced training from the manufacturer for the operation and maintenance of the equipment. · The Contractor identified that a buildup of silicon deposits on the cylinder heads of the CHPs is preventing the engines from reaching full loading and will require cleaning to resolve.	· Contractor ordered spare parts for the CHPs which arrived in December 2024 and now received both spare parts and the tools. But installation schedule is pending from the Contractor. · The Contractor was scheduled to complete the cleaning of silicon deposits on the cylinder heads and the exhaust heat exchanger replacement works by Q1 2025; the cleaning of CHP has been completed now.
Cogeneration Unit 2 (CHP 2)	· To address the ongoing NO_x exceedances recorded from October 2023 – October 2024 and January – February 2025, fine tuning of CHP 2 such as reviewing the ignition temperature curve, spark plug condition check and adjusting the intake & exhaust valves on the cylinder was conducted in May 2024 to reduce the fluctuations in NO_x emissions and to keep within the permissible limit. · To address the SO₂ exceedances recorded from October 2023 – April 2024, SO₂ sampling and testing was completed by a third-party laboratory that showed lower SO₂ values than those reported by the CEMS. The lower values measured by the laboratory was attributed to methane gas interference. Based on this study, it was proposed to implement a correction factor in the CEMS to adjust for the methane gas interference. After review by MT and IEC, the correction factor was implemented in May 2024. · To address the HCl exceedances recorded from November 2023 and April 2024, the Contractor implemented fine tuning measures such as reviewing the ignition temperature curve, spark plug condition check and adjusting the intake & exhaust valves on the cylinder to reduce the fluctuations in HCl emissions and keep within the permissible limit. · A CHP expert from Europe visited the ORRC1 facility in August 2024 to review the performance of the CHPs and recommended various spare parts be replaced. · A further tuning was carried out for the CHP on 12 August 2024. · The Contractor will receive additional advanced training from the manufacturer for the operation and maintenance of the equipment. · The Contractor identified that a buildup of silicon deposits on the cylinder heads of the CHPs is preventing the engines from reaching full loading and will require cleaning to resolve. · The Contractor received additional training for operation of the CHPs during December 2024.	· Contractor ordered spare parts for the CHPs which arrived in December 2024 and now received both spare parts and the tools. But installation schedule is pending from the Contractor. · The Contractor was scheduled to complete the cleaning of silicon deposits on the cylinder heads and the exhaust heat exchanger replacement works by Q1 2025; the cleaning of CHP has been completed now.
Cogeneration Unit 3 (CHP 3)	· To address the ongoing NO_x exceedances from October 2023 – March 2025, fine tuning measures of CHP 3 were implemented in May 2024 such as reviewing the ignition temperature curve, spark plug condition check and adjusting the intake & exhaust valves on the cylinder to reduce the fluctuations in NO_x emissions and to keep within the permissible limit. · To address the SO₂ exceedances recorded from October 2023 – April 2024, SO₂ sampling and testing was completed by a third-party laboratory that showed lower SO₂ values than those reported by the CEMS. The lower values measured by the laboratory was attributed to methane gas interference. Based on this study, it was proposed to implement a correction factor in the CEMS to adjust for the methane gas interference. After review by MT and IEC, the correction factor was implemented in May 2024. · A further tuning was carried out on 12 August 2024. · A CHP expert from Europe visited the ORRC1 facility in August 2024 to review the performance of the CHPs and recommended various spare parts be replaced. · The Contractor will receive additional advanced training from the manufacturer for the operation and maintenance of the equipment. · The Contractor identified that a buildup of silicon deposits on the cylinder heads of the CHPs is preventing the engines from reaching full loading and will require cleaning to resolve. · The Contractor received additional training for operation of the CHPs during December 2024.	· Contractor ordered spare parts for the CHPs which arrived in December 2024 and now received both spare parts and the tools. But installation schedule is pending from the Contractor. · The Contractor was scheduled to complete the cleaning of silicon deposits on the cylinder heads and the exhaust heat exchanger replacement works by Q1 2025; the cleaning of CHP has been completed now.
Ammonia Stripping Plant (ASP)	· To address the Carbon Monoxide exceedances recorded in February 2025, the Contractor arranged for a visit by the supplier to improve the reliability and performance of the system. · To address the ongoing NO_x exceedances recorded from October 2023 – March 2025, the Contractor conducted an overhaul of the ASP and arranged for a visit by the supplier to improve the reliability and performance of the system. The overhaul was completed 6 May 2024. · To address the ongoing SO₂ exceedances recorded from October 2023 – March 2025, SO₂ sampling and testing was completed by a third-party laboratory that showed lower SO₂ values than those reported by the CEMS. The lower values measured by the laboratory was attributed to methane gas interference. Based on this study, it was proposed to implement a correction factor in the CEMS to adjust for the methane gas interference. After review by MT and IEC, the correction factor was implemented in May 2024. · To address the ongoing NH₃ exceedances recorded from October 2023 – March 2025, the Contractor conducted an overhaul of the ASP and arranged for a visit by the supplier. · To address the HCl exceedances recorded from October 2023 – May 2024 and August 2024 – November 2024, and February 2025 – March 2025, the Contractor conducted an overhaul of the ASP and arranged for a visit by the supplier. · The automatic situation of the TCU louvres has been resolved as of October 2024.	· A visit from the supplier to inspect the ASP has been conducted. · The Contractor has implemented further fine-tuning measures for the ASP since December 2024; the stability of the ASP has been increased. However, it is found that the recently installed louver has resulted in some new issues which are currently under modification.

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 E.

7. future key issues

7.1 key issues for the coming month

Activities to be undertaken for the coming reporting period are:

· Implementation of various optimization measures in WWTP.

8. conclusions

This EM&A Report presents the EM&A programme undertaken during the reporting period from 1 to 31 March 2025 in accordance with the EM&A Manual (Version F) and requirements of EP (FEP-01/395/2010/C).

For the operation phase, exceedances of the emission limits for the CAPCS, CHPs, and the ASP 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
CAPCS	· No exceedance of emission limits in March 2025.
Cogeneration Unit 1 (CHP 1)	· Exceeded emission limit of NO_x on 14, 15, 16, 17, 18, 19, 20, 21, 24, 25 and 26 March 2025. · Exceeded emission limit of HCl on 16 March 2025.
Cogeneration Unit 2 (CHP 2)	· No exceedance of emission limits in March 2025.
Cogeneration Unit 3 (CHP 3)	· Exceeded emission limit of NO_x on 1, 2, 4, 5, 6, 7, 8, 9, 11, 12, 13, 14, 16, 17, 18, 21, 22, 23, 24, 25, 27, 28, 29, 30 and 31 March 2025.
Ammonia Stripping Plant (ASP)	· Exceeded emission limit of NO_x on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30 and 31 March 2025. · Exceeded emission limit of SO₂ on 25 and 26 March 2025. Exceeded emission limit of NH₃ on 1, 2, 3, 5, 9, 10, 11, 12, 23, 24, 25, 27, 28 and 29 March 2025. · · Exceeded emission limit of HCl on 25 March 2025.
Standby Gas Flaring Unit	· Exceeded emission limit of HF on 16 and 26 March 2025.

Non-compliance of emission limits of NO_x and HCl from CHP1; NO_x from CHP3; NO_x, SO_2,NH₃ and HCl from the ASP; and HF from the Standby Gas Flaring Unit were identified. The exceedances of NO_x and HCl from CHP1; NO_x from CHP3 as well as NO_x, SO₂, NH₃ and HCl from the ASP occurred due to system instability. The exceedances of HF from the Standby Gas Flaring Unit occurred due to Normal Equipment Start-up Process / stopping Process (1-3hr).

No complaint was received during the reporting period.

Discharge sample from the outlet chamber of the Effluent Storage tank was collected on 26 March 2025, but the laboratory report and result remained pending as at the date of the March 2025 EM&A report submission, and will be presented in the subsequent report .

Sample from Petrol Interceptor 1 and 2 were collected on 19 February 2025 and 27 February 2025 respectively, but the laboratory reports and results remained pending as at the date of the February 2025 EM&A report submission. Having now been received, the results are presented in this EM&A report, with all analytes in compliance with discharge limits.

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 de-sulphurisation system, the CAPCS, CHPs, and the ASP; the potential causes for the exceedances were identified.

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.