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 170.58 tonnes and treated an average of 138.12 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 standby flare, the CHPs, the ASP and the biological wastewater treatment plant (170.58t/d SSOW received); · CHP 3 overhaul; · ASP hot water pump repair works; · Completed changing of tubing on all AD mixers (commenced November 2023); and · CAPCS venturi scrubber and fan overhaul.

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 standby flare, the CHPs, the ASP and the biological wastewater treatment plant (170.58t/d SSOW received);

· CHP 3 overhaul;

· ASP hot water pump repair works;

· Completed changing of tubing on all AD mixers (commenced November 2023); and

· CAPCS venturi scrubber and fan overhaul.

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 (CHP) and the ammonia stripping plant (ASP) during the commissioning and operation phase. The most recent span calibrations for the CHPs and ASP CEMS systems were carried out from 26 to 28 September 2023. Annual CAPCS CEMS calibration was carried out from 10 to 12 October 2023.

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
Notes: (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 Table 4.8 and Table 4.9. (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).

During the reporting period, a Periodic Inspection for the Fixed Electrical Installations – High Voltage (HV) Inspection was conducted on 12 December 2023. In preparation for this HV Inspection, the Standby Gas Flaring Unit was tested on 8 December 2023 from 5:00PM to 7:00PM and from 10:00PM until 12:00AM (midnight). Since the Standby Gas Flaring Unit was run under test conditions during these periods, no values are included in Table 4.6 for these dates as this is not the normal condition/operation of the flare.

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 this 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)	0.00 – 0.00	680	Nil	Nil
Dust (or TSP)	0.00 – 0.02	6	Nil	Nil
Odour (including NH₃ & H₂S) ^(b)	0.00 – 0.99	220	Nil	Nil
Notes: (a) The VOCs emission limit includes methane as biogas is adopted, as fuel in the combustion process. (b) 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)	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 - 7	15	Nil	Nil
Carbon Monoxide	0 - 337	650	Nil	Nil
NO_x	0 – 1,694	300	Identified ^(c)	System unstable (e.g., low efficiency, unstable column temperature)
SO₂	0 – 873	50	Identified ^(d)	System unstable (e.g., low efficiency, unstable column temperature)
VOCs (including methane) ^(b)	0 – 1,066	1,500	Nil	Nil
HCl	0 – 29	10	Identified ^(e)	System unstable (e.g., low efficiency, unstable column temperature)
HF	0 - 1	1	Nil	Nil
Notes: (a) All values refer to an oxygen content in the exhaust gas of 6% and dry basis. (b) 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(5), 2(3), 3(3), 4(12), 5(4), 6(24), 7(24), 8(21), 9(21), 10(24), 11(24), 12(13), 13(19), 14(18), 15(20), 16(24), 17(24), 18(21), 19(19), 20(21), 21(24), 22(24), 23(22), 24(20), 25(24), 26(24), 27(23), 28(24), 29(24), 30(24), and 31(24) December 2023. (d) Dates with SO₂exceedances (number of exceedances on that day) were identified on 1(3), 3(3), 4(10), 5(4), 6(23), 7(20), 8(18), 9(20), 10(23), 11(7), 12(7), 13(14), 14(19), 15(20), 16(24), 17(2), 18(14), 19(16), 20(16), 21(10), 22(16), 23(11), 24(12), 25(13), 26(16), 27(8), 28(24), 29(20), 30(24), and 31(23) December 2023. (e) Date with HCl exceedance (number of exceedances on that day) was identified on 4(1) December 2023.

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 - 3	15	Nil	Nil
Carbon Monoxide	0 - 143	650	Nil	Nil
NO_x	0 – 473	300	Identified ^(c)	System unstable (e.g., low efficiency, unstable column temperature)
SO₂	0 – 139	50	Identified ^(d)	System unstable (e.g., low efficiency, unstable column temperature)
VOCs (including methane) ^(b)	0 – 1,336	1,500	Nil	Nil
HCl	0 – 2	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 2(2), 4(5), 5(4), 6(3), 8(4), 10(1), 11(3), 12(4), 13(1), 14(6), 15(16), 16(1), 17(1), 19(7), 20(10), 21(4), 23(7), 24(4), 26(1), 27(2), 29(5), 30(23), and 31(24) December 2023. (d) Dates with SO₂exceedances (number of exceedances on that day) were identified on 1(21), 2(14), 3(20), 4(22), 5(22), 6(24), 7(21), 8(18), 9(4), 10(9), 11(1), 12(3), 13(6), 15(2), 16(2), 17(16), 18(13), 19(12), 20(6), 29(4), 30(16), and 31(10) December 2023.

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 - 11	15	Nil	Nil
Carbon Monoxide	0 - 40	650	Nil	Nil
NO_x	0 – 206	300	Nil	Nil
SO₂	0 – 23	50	Nil	Nil
VOCs (including methane) ^(b)	0 – 959	1,500	Nil	Nil
HCl	0 – 1	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 4.5 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 - 4	15	Nil	Nil
Carbon Monoxide	0 - 89	650	Nil	Nil
NO_x	0 – 21,639	300	Identified ^(c)	System unstable (e.g., low efficiency, unstable column temperature)
SO₂	0 – 2,451	50	Identified ^(d)	System unstable (e.g., low efficiency, unstable column temperature)
VOCs (including methane) ^(b)	0 – 19	1,500	Nil	Nil
NH₃	0 – 20,000	35	Identified ^(e)	System unstable (e.g., low efficiency, unstable column temperature)
HCl	0 – 256	10	Identified ^(f)	System unstable (e.g., low efficiency, unstable column temperature)
HF	0 – 1	1	Nil	Nil
Notes: (a) All values refer to an oxygen content in the exhaust gas of 6% and dry basis. (b) 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(3), 4(1), 5(3), 10(1), 11(3), 12(2), 13(2), 14(12), 15(22), 16(20), 17(19), 18(22), 19(19), 20(15), 21(19), 22(3), 23(19), 24(19), 25(23), 26(22), 27(9), 28(11), 29(9), 30(1), and 31(1) December 2023. (d) Dates with SO₂exceedances (number of exceedances on that day) were identified on 5(2), 9(4), 12(5), 13(1), 15(1), 16(2), 17(13), 18(2), 21(2), 22(1), 23(3), 26(1), 28(11), 29(9), 30(23), and 31(16) December 2023. (e) Dates with NH₃ exceedances (number of exceedances on that day) were identified on 1(4), 2(8), 3(8), 4(8), 5(2), 6(11), 7(11), 8(18), 9(8), 10(3), 11(4), 12(8), 13(7), 15(3), 16(2), 17(15), 18(3), 20(1), 22(10), 23(19), 24(20), 25(24), 26(24), 27(9), 28(11), 29(10), 30(1), and 31(8) December 2023. (f) Dates with HCl exceedance (number of exceedances on that day) were identified on 17(13), 18(2), 22(1), 23(18), 24(19), 25(23), 26(22), 27(9), 28(10), and 29(9) December 2023.

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

Parameter	Range of Hourly Average Conc. (mg/Nm³) ^(a)	Emission Limit (mg/Nm³)	Exceedance Identified	Remarks
Dust (or TSP)	0 – 0	5	Nil	Nil
Carbon Monoxide	0 – 0	100	Nil	Nil
NO_x	0 – 0	200	Nil	Nil
SO₂	0 – 0	50	Nil	Nil
VOCs (including methane) ^(b)	0 – 0	20	Nil	Nil
HCl	0 – 0	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.

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 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 Interceptors are recorded in Tables 4.8 – 4.9.

Table 4.7 Results of the Discharge Sample from the Outlet Chamber of the Effluent Storage Tank

Parameter	Discharged Effluent Concentration (mg/L)	Discharge Limit (mg/L)	Compliance with Discharge Limit
Flow Rate (m³/day)^(a)	32 - 231^(e)	645	Yes
pH (pH units)^(b)	7.30 – 7.90^(e)	6 - 10^(c)	Yes
Suspended Solids ^{(b) (d)}	214 ^(d)	800	Yes
Biochemical Oxygen Demand (5 days, 20°) ^{(b) (d)}	27 ^(d)	800	Yes
Chemical Oxygen Demand ^{(b) (d)}	1,030 ^(d)	2,000	Yes
Oil & Grease ^{(b) (d)}	<5 ^(d)	40	Yes
Total Nitrogen ^{(b) (d)}	100 ^(d)	200	Yes
Total Phosphorus ^{(b) (d)}	33.4 ^(d)	50	Yes
Surfactants (total)^{(b) (d)}	<1.0 ^(d)	25	Yes
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) Effluent sample collected on 13 December 2023. (e) Data collected daily.

Table 4.8 Results of the Discharge Sample from the Petrol Interceptor 1

Parameter	Discharged Effluent Concentration (mg/L)	Discharge Limit (mg/L)	Compliance with Discharge Limit
Suspended Solids^(b)	23 ^(a)	30	Yes
Chemical Oxygen Demand ^(c)	53 ^(a)	80	Yes
Oil & Grease ^(c)	11 ^(a)	20	Yes
Surfactants (total)^(b)	<1.0 ^(a)	15	Yes
Notes: (a) Petrol Interceptor 1 sample collected on 13 December 2023. (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

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)	<5 ^(a)	80	Yes
Oil & Grease ^(c)	<5 ^(a)	20	Yes
Surfactants (total)^(b)	<1.0 ^(a)	15	Yes
Notes: (a) Petrol Interceptor 2 sample collected on 20 December 2023. (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.

4.4 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 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)
December 2023	0 L ^(d)	1006.03 tonnes	0.000 tonnes	2.765 tonnes^(e)	0.016 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, 0.009 tonnes of papers/cardboard packing and 0.006 tonnes of plastics were sent to recyclers for recycling during the reporting period. (d) No chemical waste was disposed of at CWTC in December 2023. (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 19 December 2023 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:

19 December 2023

· 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 audit

Inspection of the landscape and visual mitigation measures for the operation phase of the Project was performed on 19 December 2023.

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 19 December 2023. 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.

([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 operates 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.

Stack	Exceedances During the Reporting Period
Cogeneration Unit 1 (CHP 1)	· Exceeded emission limit of NO_x on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31 December 2023 · Exceeded emission limit of SO₂ on 1, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31 December 2023. · Exceeded emission limit of HCl on 4 December 2023.
Cogeneration Unit 2 (CHP 2)	· Exceeded emission limit of NO_x on 2, 4, 5, 6, 8, 10, 11, 12, 13, 14, 15, 16, 17, 19, 20, 21, 23, 24, 26, 27, 29, 30, and 31 December 2023. · Exceeded emission limit of SO₂ on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 29, 30, and 31 December 2023.
Ammonia Stripping Plant (ASP)	· Exceeded emission limit of NO_x on 1, 4, 5, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31 December 2023. · Exceeded emission limit of SO₂on 5, 9, 12, 13, 15, 16, 17, 18, 21, 22, 23, 26, 28, 29, 30, and 31 December 2023. · Exceeded emission limit of NH₃ on 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 15, 16, 17, 18, 20, 22, 23, 24, 25, 26, 27, 28, 29, 30, and 31 December 2023. · Exceeded emission limit of HCl on 17, 18, 22, 23, 24, 25, 26, 27, 28, and 29 December 2023.

air Quality monitoring

Water Quality

Waste Management

Section 1: Introduction

Section 2: Project Information

Section 3: Environmental Monitoring and Audit Requirements

Section 4: Monitoring Results

Section 5: Site Audit

Section 6: Environmental Non-conformance

Section 7: Further Key Issues

Section 8: Conclusions

2.2 general site description

3.2 SITE AUDIT

3.2.2 LANDSCAPE AND VISUAL

4.2 odour

4.4 waste management