A landscape with a city and land

Description automatically generated with medium confidence

A close-up of a document

Description automatically generated

A document with a signature

Description automatically generated with medium confidence

 

Contents

Executive Summary                                                                                      

1                      Introduction                                                                           

1.1                   Background                                                                            

1.2                   Project Description                                                            

1.3                   Scope of the EM&A Report                                                

1.4                   Project Organisation                                                        

1.5                   Summary of Construction Works                                

1.6                   Summary of EM&A Programme Requirements          

1.7                   Status of Statutory Environmental Compliance with the Environmental Permit                                                

1.8                   Status of Other Statutory Environmental Requirements                                                                         

2                      EM&A Results                                                                          

2.1                   Air Quality Monitoring                                                       

2.2                   Noise Monitoring                                                                   

2.3                   Water Quality Monitoring                                                

2.4                   Landfill Gas Monitoring                                                   

2.5                   Landscape and Visual Monitoring                                

2.6                   EM&A Site Inspection                                                            

2.7                   Waste Management Status                                              

2.8                   Implementation Status of Environmental Mitigation Measures                                                                                  

2.9                   Summary of Exceedances of the Environmental Quality Performance Limit                                               

2.10                 Summary of Complaints, Notification of Summons and Successful Prosecutions                                                

3                      Conclusion and Recommendation                                 

 


 

Annexes

Annex A   Work Programme

Annex B   Environmental Mitigation Implementation Schedule

Annex C   Monitoring Schedule for This Reporting Period

Annex D   Air Quality
Annex D1 24-hour TSP Monitoring Results
Annex D2 Event and Action Plan for Air Quality Monitoring
Annex D3 Meteorological Data

Annex D4 Odour Monitoring Results

Annex D5 Thermal Oxidizer, Landfill Gas Flare and Landfill Gas Generator Stack Emission Monitoring Results

Annex D6 Ambient VOCs, Ammonia and H2S Monitoring Results

Annex D7 Investigation Reports of Environmental Quality Limit Exceedance

Annex E   Noise
Annex E1 Noise Monitoring Results
Annex E2 Event and Action Plan for Noise Monitoring

Annex F   Water Quality
Annex F1 Surface Water Quality Monitoring Results
Annex F2 Event and Action Plan for Water Quality Monitoring
Annex F3 Leachate Levels Monitoring Results

Annex F4 Effluent Quality Monitoring Results

Annex F5 Groundwater Monitoring Results

Annex F6 Investigation Reports of Environmental Quality Limit Exceedance

Annex G  Landfill Gas
Annex G1 Landfill Gas Monitoring Locations for Service Voids, Utilities and Manholes Along the Site Boundary and Within the SENTX Site

Annex G2 Landfill Gas Monitoring Results
Annex G3 Event and Action Plan for Landfill Gas Monitoring

Annex G4 Investigation Reports of Environmental Quality Limit Exceedance

Annex H   Cumulative Statistics on Exceedances, Environmental Complaints, Notification of Summons and Status of Prosecutions

 

 

Executive Summary

The SENT Landfill Extension (SENTX) forms an integral part in the Strategic Plan in maintaining the continuity of landfill capacity in the Hong Kong for the cost-effective and environmentally satisfactory disposal of waste.  ERM-Hong Kong, Limited (ERM) is commissioned to undertake the role of Environmental Team (ET) for the construction, operation/restoration and aftercare of SENTX Project (“the Project”) in accordance with the requirements specified in the Environmental Permit (EP), updated Environmental Monitoring and Audit (EM&A) Manual, the approved Environmental Impact Assessment (EIA) Report of the Project taking account of the latest design and other relevant statutory requirements.  The construction (not including works related to site clearance and preparation) and operation of the Project commenced on 2 January 2019 and 21 November 2021, respectively.

This Annual EM&A Report presents the EM&A works carried out during the period from 1 January to 31 December 2022 for the Project in accordance with the updated EM&A Manual. 

Exceedance of Action and Limit Levels for Air Quality

Two exceedances of the Action and Limit Levels for dust (TSP), two exceedances of the Limit Level for landfill gas flare stack emission (SO2) and one exceedance of Limit Level for landfill gas flare stack emission (Benzene) were recorded for air quality monitoring in the reporting period.

The TSP exceedance at AM2 on 29 July 2022 was considered Project-related while the exceedance at AM4 on 29 July 2022 was considered non Project-related upon further investigation.

The landfill gas flare stack emission (SO2) exceedances on 14 October 2022 and 17 November 2022 and landfill gas flare stack emission (Benzene) exceedance on 13 December 2022 were considered Project-related upon further investigation.

Exceedance of Action and Limit Levels for Noise

No exceedance of Action and Limit Levels for operation/ restoration phase noise monitoring was recorded in the reporting period.

Exceedance of Action and Limit Levels for Water Quality

Eight exceedances of the Limit Level for groundwater (Chemical Oxygen Demand (COD)), three exceedances of the Limit Level for surface water (suspended solid (SS)), sixteen exceedances of the Limit Level for leachate level and one exceedance of Limit Level for leachate quality (Chromium) were recorded for water quality impact monitoring in the reporting period.

The SS exceedances at DP4 on 25 May 2022, 30 June 2022 and 8 July 2022 were found deemed to Project-related activities and weekly surface water quality (SS) monitoring has been commenced since June 2022.  The additional surface water monitoring results (SS) at DP4 on 15 July 2022 complied with the Limit Level as stipulated in the updated EM&A Manual and the weekly surface water monitoring (SS) at DP4 was terminated.

The groundwater (COD) exceedances at MWX-4 and MWX-6 on 15 February 2022, at MWX-4 on 15 March 2022, at MWX-4, MWX5 and MWX6 on 11 April 2022 and at MWX-7 on 18 August 2022 and 6 September 2022 were considered non Project-related upon further investigation.

The leachate level exceedances at Pump Station No. 4X from 12 August to 20 August 2022, from 30 September 2022 to 3 October 2022 and from 3 November 2022 to 4 November 2022, and at Pump Station No. 3X on 3 November 2022 were considered Project-related upon further investigation. 

The leachate quality (Chromium) exceedance on 6 December 2022 was considered Project-related upon further investigation.

Exceedance of Action and Limit Levels for Landfill Gas

Two exceedances of the Limit Level for methane were recorded for perimeter landfill gas monitoring in the reporting period.  The landfill gas (methane) exceedances at LFG6 on 17 May 2022 and at LFG13 on 3 October 2022 were considered non Project-related upon further investigation.

Environmental Complaints, Summons and Prosecutions

There were no complaints, notification of summons or prosecution recorded in the reporting period.

Reporting Change

There was no reporting change in the reporting period.


1                                    Introduction

1.1                               Background

The SENT Landfill Extension (SENTX) forms an integral part in the Strategic Plan in maintaining the continuity of landfill capacity in the Hong Kong for the cost-effective and environmentally satisfactory disposal of waste.  The Environmental Impact Assessment (EIA) Report and the associated Environmental Monitoring and Audit (EM&A) Manual for the construction, operation, restoration and aftercare of the SENTX (hereafter referred to as “the Project”) have been approved under the Environmental Impact Assessment Ordinance (EIAO) in May 2008 (Register No.: AEIAR-117/2008) (hereafter referred to as the approved EIA Report) and an Environmental Permit (EP-308/2008) (EP) was granted by the Director of Environmental Protection (DEP) on 5 August 2008. 

Since then, applications for Variation of an Environmental Permit (No. VEP-531/2017) were submitted to EPD and the Variation of Environmental Permits (EP-308/2008/A and EP-308/2008/B) were granted on 6 January 2012 and 20 January 2017, respectively, as the Hong Kong SAR Government has decided to reduce the scale of the design scheme of SENTX assessed in the approved EIA Report and SENTX will only receive construction waste.  In May 2018, a Further Environmental Permit (FEP) (FEP-01/308/2008/B) was granted to the SENTX’s contractor, Green Valley Landfill, Limited (GVL).

ERM-Hong Kong, Limited (ERM) and Meinhardt Infrastructure and Environment Limited (Meinhardt) are commissioned to undertake the roles of Environmental Team (ET) and the Independent Environmental Checker (IEC), respectively, to undertake the EM&A activities for the Project in accordance with the requirements specified in the EP, updated EM&A Manual ([1]), approved EIA Report ([2]) taking account of the latest design and other relevant statutory requirements.

1.2                               Project Description

The SENTX is a piggyback landfill, occupying the southern part of the existing SENT Landfill (including its infrastructure area) and 13 ha of Tseung Kwan O (TKO) Area 137.  A layout plan of the SENTX is shown in Figure 1.1.  Under the latest design, the SENTX has a net void capacity of about 6.5 Mm3 and provides an additional lifespan of about 6 years, commencing operation upon exhaustion of the SENT Landfill.  The SENTX will receive construction waste only.

The key implementation milestones of the Project are indicatively summarised in Table 1.1.  The construction works and operation of the Project commenced on 2 January 2019 and 21 November 2021, respectively.  

Table 1.1        Estimated Key Dates of Implementation Programme

Key Stage of the Project

Indicative Date

Start construction

2 January 2019

Commissioning of new infrastructure facilities

2020

Demolition of existing infrastructure facilities

2021

Start waste intake at SENTX

21 November 2021

Estimated exhaustion date of SENTX

2027

End of aftercare for SENTX

2057

The major construction works of the SENTX includes:

·        Site formation at the TKO Area 137 and the existing infrastructure area at SENT Landfill;

·        Construction of surface and groundwater drainage systems;

·        Construction of the leachate containment and collection systems;

·        Construction of new leachate and landfill gas treatment facilities, site offices, maintenance yards at the new infrastructure area;

·        Construction of new pipelines to transfer the leachate and landfill gas collected from the existing SENT Landfill to the treatment facilities at the new infrastructure area;

·        Construction of the site access and new waste reception facilities; and

·        Demolition of the facilities at the existing SENT Landfill infrastructure area.

1.3                               Scope of the EM&A Report

This is the Annual EM&A Report for the Project which summarises the key findings of the EM&A programme during the reporting period from 1 January to 31 December 2022 for the operation works.

1.4                               Project Organisation

The organisation structure of the Project is presented in Figure 1.2

Figure 1.2      Organisation Chart

 

A diagram of a project

Description automatically generated

 

Contact details of the key personnel are summarized in Table 1.2 below.

Table 1.2        Contact Information of Key Personnel

Party

Position

Name

Telephone

Contractor

(Green Valley Landfill Limited)

Project Manager

Carl Lai

2706 8829

 

 

 

Environmental Team (ET) (ERM-Hong Kong, Limited)

 

ET Leader

Terence Fong

2271 3156

Independent Environmental Checker (IEC)

(Meinhardt Infrastructure and Environment Limited)

 

IEC

Claudine Lee

2859 5409

1.5                               Summary of Construction Works

The programme of the construction is shown in Annex A.  As informed by the Contractor, the major works carried out in this reporting period include:

January 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of pump house 4X;

·           Construction of MSE wall;

·           Site formation for Cell 4X;

·           Liner works at Cell 4X; and

·           Maintenance and improvement of temporary surface water drainage.

February 2022

·           Rectification of defects at LFG Plant, LTP, infrastructure area and waste reception area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of MSE wall;

·           Site formation for Cell 4X;

·           Liner works at Cell 4X;

·           Construction of perimeter channel along Western bund of Cell 4X; and

·           Maintenance and improvement of temporary surface water drainage.

March 2022

·           Rectification of defects at LFG Plant, LTP, infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of MSE wall;

·           Construction of retaining wall at Western boundary planting;

·           Liner works at Cell 4X;

·           Construction of perimeter channel X10A and X10C along Western bund of Cell 4X;

·           Maintenance and improvement of temporary surface water drainage; and

Utilities installation along Western bund of Cell 4X.

April 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of MSE wall;

·           Construction of retaining wall at Western boundary planting;

·           Liner works at Cell 4X;

·           Construction of perimeter channel X10A and X10C along Western bund of Cell 4X;

·           Maintenance and improvement of temporary surface water drainage; and

·           Utilities installation along Western bund of Cell 4X.

May 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe, road pavement of EVA along Western Bund from main entrance to infrastructure;

·           Construction of road pavement on top of the MSE wall;

·           Construction of Cell 4X and SENT tie in area;

·           Construction of perimeter channel X10A and X10C along Western bund of Cell 4X;

·           Maintenance and improvement of temporary surface water drainage;

·           Deployment of liner at Buttress Wall area;

·           Equipment installation at Sump House 4; and

·           Utilities installation along Western bund of Cell 4X.

June 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of road pavement on top of the MSE wall;

·           Construction of Cell 4X and SENT tie in area;

·           Construction of perimeter channel X10A and X10C along Western bund of Cell 4X;

·           Maintenance and improvement of temporary surface water drainage;

·           Deployment of liner at Buttress Wall area;

·           Equipment installation at Sump House 4; and

·           Utilities installation along Western bund of Cell 4X.

July 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of road pavement on top of the MSE wall;

·           Construction of Cell 4X and SENT tie in area;

·           Construction of perimeter channel X10A and X10C along Western bund of Cell 4X;

·           Maintenance and improvement of temporary surface water drainage; and

·           Rectification of utilities installation along Western bund of Cell 4X.

August 2022

·           Rectification of defects at LFG Plant, LTP, infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of Cell 4X and SENT tie in area;

·           Construction of road pavement at diesel fuel tank and installation of railing;

·           Construction of road pavement at Western perimeter bund;

·           Maintenance and improvement of temporary surface water drainage; and

·           Rectification of utilities installation along Western bund of Cell 4X.

September 2022

·           Rectification of defects at LFG Plant, LTP, infrastructure area and waste reception area;

·           Landscaping works at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of Cell 4X and SENT tie in area and rock wall;

·           Deployment of liner at cell 4X and SENT tie in area;

·           Installation of GMS frame for roof planter at roof floor of GVL , EPD and lab building;

·           Construction of concrete plinth for pump and concrete kerb for inlet box at the top of diesel fuel tank;

·           Maintenance and improvement of temporary surface water drainage; and

·           Rectification of utilities installation along Western bund of Cell 4X.

October 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Installation of roof planter at infrastructure area;

·           Rectification of defects for underground utilities and pipe;

·           Construction of Cell 4X and SENT tie in area and rock wall;

·           Demolition of existing DP3 channel;

·           Tree removal at Cell 4X and SENT tie in area;

·           Deployment of liner at Cell 4X and SENT tie in area;

·           Maintenance and improvement of temporary surface water drainage; and

·           Rectification of utilities installation along Western bund of Cell 4X.

November 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Construction of Cell 4X and SENT tie in area;

·           Maintenance and improvement of temporary surface water drainage;

·           Rectification of utilities installation along Western bund of Cell 4X;

·           Deployment of 1350g/m2 non-woven geotextile cushion layer at Cell 4X Buttress Wall 1st bench; and

·           Deployment of 540g/cm2 non-woven geotextile, geocomposite, GCL, 60mil HDPE double-textured geomembrane, 80mil HDPE double-textured geomembrane at Cell 4X (tie-in with SENT landfill) at North side.

December 2022

·           Rectification of defects at Landfill Gas (LFG) Plant, Leachate Treatment Plant (LTP), infrastructure area and waste reception area;

·           Construction of Cell 4X tie-in to SENT and rockwall;

·           Construction of Cell 4X overflow weir;

·           Maintenance and improvement of temporary surface water drainage; and

·           Construction of DP3 leachate pipe connection.

The implementation schedule of the mitigation measures recommended in the Updated EM&A Manual is presented in Annex B.

1.6                               Summary of EM&A Programme Requirements

The status for all environmental aspects are presented in Table 1.3.  The EM&A requirements remained unchanged during the reporting period.

Table 1.3        Summary of Status for the Environmental Aspects under the Updated EM&A Manual

Parameters

Status

Air Quality

Baseline Monitoring

The results of baseline air quality monitoring were reported in Baseline Monitoring Report and Pre-operation Baseline Monitoring Report and submitted to EPD under EP Condition 3.3

Impact Monitoring

On-going

Noise

Baseline Monitoring

The results of baseline noise monitoring were reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.3

Impact Monitoring

On-going

Water Quality

Baseline Monitoring

The results of baseline water quality monitoring were reported in Baseline Monitoring Report and Pre-operation Baseline Monitoring Report and submitted to EPD under EP Condition 3.3

Impact Monitoring

On-going

Landfill Gas

Baseline Monitoring

The results of baseline landfill gas monitoring were reported in Pre-operation Baseline Monitoring Report and submitted to EPD under EP Condition 3.3

Impact Monitoring

On-going

Waste Management

Waste Monitoring

On-going

Landscape and Visual

Baseline Monitoring

The results of baseline landscape and visual monitoring were reported in Baseline Monitoring Report and submitted to EPD under EP Condition 3.3

Construction Phase Audit

On-going

Site Environmental Audit

Regular Site Inspection

On-going

Complaint Hotline and Email Channel

On-going

Environmental Log Book

On-going

Taking into account the operation works, impact monitoring of air quality, noise, water quality, landfill gas and waste management were carried out in the reporting period.  The impact monitoring schedule of air quality, noise, water quality and landfill gas monitoring are provided in Annex C

The EM&A programme also involved environmental site inspections and related auditing conducted by the ET for checking the implementation of the required environmental mitigation measures recommended in the approved EIA Report and relevant EP submissions. To promote the environmental awareness and enhance the environmental performance of the contractors, environmental trainings and regular environmental management meetings were conducted during the reporting period, which are summarised as below:

Ÿ   Twelve environmental management meetings were held with the Contractor, ER, ET, IEC and EPD on 20 January, 24 February, 24 March, 21 April, 19 May, 23 June, 21 July, 18 August, 15 September, 20 October, 17 November and 15 December 2022; and

Ÿ   Environmental toolbox trainings on the following topics were provided by the Contractor to the workers:

Ÿ   Site Practice for Waste Reduction in Construction Industry on 4 January 2022;

Ÿ   Clean Recycling on 18 January 2022;

Ÿ   Quality Powered Mechanical Equipment (QPME) on 9 February 2022;

Ÿ   Good Vehicle Maintenance Practices on 23 February 2022;

Ÿ   Chemical Waste Handling on 9 March 2022;

Ÿ   Green Procurement on 23 March 2022;

Ÿ   Persistent Organic Pollutants on 6 April 2022;

Ÿ   Mosquito Control on 20 April 2022;

Ÿ   Cut Down Construction Dust on 11 May 2022;

Ÿ   Indoor Air Quality on 25 May 2022;

Ÿ   Trip Ticket System on 8 June 2022;

Ÿ   Wastewater Management on 22 June 2022;

Ÿ   Illegal Dumping on 6 July 2022;

Ÿ   Air Pollution – Dark Smoke on 21 July 2022;

Ÿ   Noise Control Ordinance on 11 August 2022;

Ÿ   NRMM on 29 August 2022;

Ÿ   Waste Reduction on Construction Industry on 7 September 2022;

Ÿ   Renewable Energy on 27 September 2022;

Ÿ   Good Vehicle Maintenance Practices on 5 October 2022;

Ÿ   Mosquito Prevention on 19 October 2022;

Ÿ   VOC and Smog on 9 November 2022;

Ÿ   QPME on 23 November 2022;

Ÿ   Construction Dust on 7 December 2022; and

Ÿ   Chemical Waste Handling on 21 December 2022.

The status of statutory environmental compliance with the EP conditions under the EIAO, submission status under the EP and implementation status of the recommended mitigation measures are presented in Table 1.4.  

Table 1.4        Status of Submissions required under the EP and Implementation Status of the recommended Mitigation Measures

EP Condition

Submission / Implementation Status

Status

2.3

Management Organisation of Main Construction Companies

Submitted and accepted by EPD.

2.4

Setting up of Community Liaison Group

Community Liaison Group was set up.

2.5

Submission of Detailed Landfill Gas Hazard Assessment Report

Submitted, and accepted by EPD on 10 January 2019.

2.6

Submission of Restoration and Ecological Enhancement Plan

Submitted to EPD on 28 June 2019.

2.7

Setting up of Trial Nursery

Trial Nursery works was commenced on 28 August 2019.

2.8

Advance Screen Planting

Advance Screen Planting works were completed on 28 June 2019.

2.9

Provision of Multi-layer Composite Liner System

Under implementation.

1.7                               Status of Other Statutory Environmental Requirements

The environmental licenses and permits (including EP, Water Pollution Control Ordinance (WPCO) discharge license, registration as a chemical waste producer, and construction noise permit) that are valid in the reporting period are presented in Table 1.5.  No non-compliance with environmental statutory requirements was identified.  

Table 1.5        Status of Statutory Environmental Requirements

Description

Ref No.

Status

Environmental Permit

EP-308/2008

Granted on 5 August 2008

Variation of Environmental Permit

EP-308/2008/A

Granted on 6 January 2012

EP-308/2008/B

Granted on 20 January 2017

Further Environmental Permit

FEP-01/308/2008/B

Granted on 16 May 2018

Water Discharge License under WPCO (Permit Holder: GVL)

Licence No.: WT00036269-2020

Validity from 21 June 2020 to 30 June 2022

Licence No.: WT00041447-2022

Validity from 17 June 2022 to 30 June 2024

Billing Account for Disposal of Construction Waste

Chit Account Number: 5001692

Approved on 28 December 2005

Registration as a Chemical Waste Producer (Permit Holder: Chun Wo)

5213-839-C3507-10

Issued on 23 August 2018

Registration as a Chemical Waste Producer (Permit Holder: REC)

5518-839-R2289-06

Issued on 24 October 2019

Registration as a Chemical Waste Producer (Permit Holder: GVL)

5296-839-G2228-01

Issued on 31 December 2015

Construction Noise Permit (Permit Holder: GVL)

GW-RE0990-21

Validity from 6 October 2021 to 5 April 2022

 

GW-RE1316-21

Validity from 5 January 2022 to 14 June 2022

 

GW-RE0565-22

Validity from 15 June 2022 to 14 December 2022

 

GW-RE0956-22

Validity from 23 September 2022 to 14 March 2023

Construction Noise Permit (Permit Holder: Paul Y.)

GW-RE1138-21

Validity from 16 November 2021 to 15 February 2022

 

GW-RE0278-22

Validity from 31 March 2022 to 22 September 2022

2                                    EM&A Results

The EM&A programme for the Project required environmental monitoring for air quality, noise, water quality and landfill gas as well as environmental site inspections for air quality, noise, water quality, landfill gas, waste management, and landscape and visual impacts.  The EM&A requirements and related findings for each component are summarised in the following sections.

2.1                               Air Quality Monitoring

2.1.1                          Dust Monitoring

Monitoring Requirements and Equipment

According to the updated EM&A Manual of the Project, impact dust monitoring (in term of Total Suspended Particulates (TSP)) was carried out at the four designated locations along the site boundary (i.e. AM1, AM2, AM3 and AM4) during the operation/restoration phase, at a 6-day interval.

The Action and Limit Levels of the air quality monitoring is provided in Table 2.1 below.

Table 2.1        Action and Limit Levels for 24-hour TSP

Monitoring Station                

Action Level

Limit Level

AM1 - SENTX Site Boundary (North)

260 µg m-³

260 µg m-³

AM2 - SENTX Site Boundary (West, near DP3)

AM3 - SENTX Site Boundary (West, near RC15)

AM4 - SENTX Site Boundary (West, near EPD building)

High volume air samplers (HVSs) in compliance with the specifications listed under Section 3.2.2 of the updated EM&A Manual were used to measure 24-hour TSP levels at the CEDD dust monitoring stations.  The HVSs were calibrated upon installation and thereafter at bi-monthly intervals to check the validity and accuracy of the results.

The equipment used in the impact air quality monitoring programme and monitoring locations are summarised in Table 2.2 and illustrated in Figure 2.1 respectively.




Table 2.2        Dust Monitoring Details

Monitoring Station

Location

Parameter

Frequency and Duration

Monitoring Dates

Equipment

AM1

SENTX Site Boundary (North)

24-hour TSP

Once every 6 days

6, 12, 18, 24, 30 Jan 2022

 

5, 11, 17, 23 Feb 2022

 

1, 7, 13, 19, 25, 31 Mar 2022

 

6, 12, 18, 24, 30 Apr 2022

 

6, 12, 18, 24, 30 May 2022

 

5, 11, 15, 17, 23, 29 Jun 2022

 

5, 11, 17, 23, 29 Jul 2022

 

4, 10, 16, 22, 28 Aug 2022

 

3, 9, 15, 21, 27 Sep 2022

 

3, 9, 15, 21, 27 Oct 2022

 

2, 8, 14, 20, 26 Nov 2022

 

2, 8, 14, 20, 21, 26 Dec 2022

 

Tisch TE-5170 (S/N: 1190)

AM2

SENTX Site Boundary (West, near DP3)

Tisch TE-5170 (S/N: 1047)

AM3

SENTX Site Boundary (West, near RC15)

Tisch TE-5170 (S/N: 1258)

AM4

SENTX Site Boundary (West, near EPD building)

Tisch TE-5170 (S/N: 1101)

Monitoring Schedule for the Reporting Period

The schedule for air quality monitoring during the reporting period is provided in Annex C.

Results and Observations

The 24-hour TSP monitoring results are summarised in Table 2.3.  The detailed monitoring results and the graphical presentation of the 24-hour TSP monitoring results at each monitoring location are provided in Annex D1.



Table 2.3        Summary of 24-hour TSP Monitoring Results in the Reporting Period

Month

Monitoring Station

24-hr TSP Concentration (µg m-3)

Action Level  (µg/m3)

Limit Level  (µg/m3)

Average

Range

January 2022

AM1

133

55 – 210

260

260

AM2

66

32 – 102

260

260

AM3

150

100 – 218

260

260

AM4

105

53 – 132

260

260

February 2022

 

AM1

73

42 – 132

260

260

AM2

56

32 – 85

260

260

AM3

100

57 – 140

260

260

AM4

75

47 – 107

260

260

March 2022

AM1

96

62 – 133

260

260

 

AM2

70

39 – 106

260

260

 

AM3

163

35 – 224

260

260

 

AM4

81

33 – 107

260

260

April 2022

AM1

61

45 – 84

260

260

 

AM2

57

46 – 78

260

260

 

AM3

133

69 – 169

260

260

 

AM4

92

58 – 142

260

260

May 2022

AM1

54

39 – 68

260

260

 

AM2

49

24 – 69

260

260

 

AM3

83

43 – 127

260

260

 

AM4

54

34 – 72

260

260

June 2022

AM1

45

26 – 80

260

260

 

AM2

90

56 – 123

260

260

 

AM3

113

42 – 198

260

260

 

AM4

92

41 – 218

260

260

July 2022

AM1

69

39 – 156

260

260

 

AM2

127

43 – 312

260

260

 

AM3

119

56 – 241

260

260

 

AM4

144

42 – 364

260

260

August 2022

AM1

61

26 – 94

260

260

 

AM2

67

36 – 111

260

260

 

AM3

95

43 – 150

260

260

 

AM4

67

35 – 134

260

260

September 2022

AM1

135

58 – 174

260

260

 

AM2

133

69 – 190

260

260

 

AM3

195

118 – 252

260

260

 

AM4

149

102 – 207

260

260

October 2022

AM1

93

64 - 136

260

260

 

AM2

87

71 - 126

260

260

 

AM3

134

111 - 194

260

260

 

AM4

118

66 - 243

260

260

November 2022

AM1

111

45 - 228

260

260

 

AM2

59

33 - 95

260

260

 

AM3

83

45 - 126

260

260

 

AM4

55

37 - 67

260

260

December 2022

AM1

107

29 - 225

260

260

 

AM2

89

34 - 121

260

260

 

AM3

124

66 - 180

260

260

 

AM4

100

55 - 136

260

260

The major dust sources in the reporting period included fugitive dust emission from exposed area in SENTX, as well as nearby operations of the SENT landfill and the TKO Area 137 Fill Bank.

Action and Limit Levels exceedances were recorded for TSP monitoring in the reporting period and actions in accordance with the Event and Action Plan presented in Annex D2 were undertaken.  Investigation of the Action and Limit Levels exceedances were conducted and the investigation reports are presented in Annex D7.

Based on the investigation conducted for the monitoring event with potential Action and Limit Levels exceedance with the Contractor and the IEC, the TSP exceedance at AM2 on 29 July 2022 was considered Project-related while the exceedance at AM4 on 29 July 2022 was considered non-Project-related. 

The Contractor was reminded to implement all relevant mitigation measures for the construction and operation works and maintain good site practice.  The ET will keep track on the monitoring data and ensure Contractor’s compliance of the environmental requirements.

Meteorological Data

Meteorological data obtained from the SENTX on-site meteorological monitoring station was used for the dust monitoring and is shown in Annex D3.  It is considered that meteorological data obtained at the on-site meteorological monitoring station is representative of the Project area and could be used for the operation/restoration phase dust monitoring programme for the Project.

2.1.2                          Odour Monitoring

Monitoring Requirements

According to the updated EM&A Manual of the Project, odour patrol was carried out along the site boundary during the operation/ restoration phase.

During the first month of operation, daily odour patrol (3 times per day) was conducted jointly by the ET and the IEC.  The odour intensity detected was based on that determined by the IEC. In addition, an independent party (ALS Technichem (HK) Pty Ltd.) was appointed to undertake odour patrol together with the ET and IEC three times per week.  During these patrols, the odour intensity detected was based on that determined by the independent third party.

Reduction of odour monitoring frequency from Period 1 (daily, three times per day) to Period 2 (weekly)) was approved by EPD on 4 February 2022. Weekly odour patrol was conducted jointly by the ET and the IEC from 4 February 2022. In addition, an independent party (ALS Technichem (HK) Pty Ltd.) was appointed to undertake odour patrol together with the ET and IEC once every two weeks.

Reduction of odour monitoring frequency from Period 2 (weekly) to Period 3 (monthly) was approved by EPD on 2 June 2022. Monthly odour patrol was conducted jointly by the ET and the IEC from 28 June 2022. In addition, an independent party (ALS Technichem (HK) Pty Ltd.) was appointed to undertake odour patrol together with the ET and IEC quarterly. 

The Action and Limit Levels for odour patrol is provided in Table 2.4 below.

Table 2.4        Action and Limit Levels for Odour Patrol

Parameter

Action Level

Limit Level

Perceived odour intensity and odour complaints

·      Odour intensity ≥ Class 2 recorded; or

·      One documented complaint received

·      Odour intensity ≥ Class 3 recorded on 2 consecutive patrol (a) (b)

 

Notes:

(a)    i.e. either Class 3-strong or Class 4-extreme odour intensity.

(b)    The exceedances of the odour intensity do not need to be recorded at the same location.

Odour patrol was conducted by trained personnel / competent persons with a specific sensitivity to a reference odour (i.e. on reference materials n-butanol with the concentration of 50ppm in nitrogen (v/v)) in compliance with Section 3.7.2 of the updated EM&A Manual patrolling and sniffing along the SENTX Site boundary to detect any odour.

The odour monitoring programme and patrol route are summarised in Table 2.5 and illustrated in Figure 2.2 respectively.

Table 2.5        Odour Monitoring Details

Patrol Locations

Parameters

Patrol Frequency (a)

Monitoring Dates and Time

Patrol along the SENTX Site Boundary (Checkpoints OP1 – OP17)

Odour Intensity (see Table 2.6)

Period 1 - First month of operation

Daily, three times a day in the morning, afternoon and evening/night (between 18:00 and 22:00 hrs) conducted by the ET and the IEC

 

Three times per week on different days conducted by an independent third party together with the ET and IEC (b)

 

Period 2 - Three months following period 1 (c)

 

Weekly conducted by the ET and the IEC

 

Once every two weeks conducted by an independent third party together with the ET and IEC (b)

 

Period 3 - Throughout operation following period 2 (c)

Monthly conducted by the ET and the IEC

 

Quarterly conducted by an independent third party together with the ET and IEC (b)

Conducted by ET & IEC:

1 – 31 Jan 2022

 

1 – 4, 18, 28 Feb 2022

 

7, 16, 21, 29 Mar 2022

 

12, 25 Apr 2022

 

10, 23 May 2022

 

22 Jul 2022

 

22 Aug 2022

 

13 Oct 2022

 

24 Nov 2022

 

Conducted by an independent third party, ET & IEC:

1, 7, 10, 12, 14, 17, 18, 19, 24, 25, 27, 31 Jan 2022

 

4, 11, 21 Feb 2022

 

7, 21 Mar 2022

 

7, 22 Apr 2022

 

4, 17, 30 May 2022

 

28 Jun 2022

 

15 Sep 2022

 

13 Dec 2022

Notes:

(a)    Reduction of monitoring frequency will be subject to the monitoring results to demonstrate environmentally acceptable performance.

(b)    Patrol shall be scheduled so that they are carried out together with the patrols to be carried out jointly by the ET and the IEC.

(c)    Commencement of each period will be justified by the ET Leader and verified by the IEC and will be subject to agreement with the EPD (EIAO Authority) and Project Proponent.





Table 2.6        Odour Intensity Level

Class 

Odour Intensity

Description

0

Not Detected

No odour perceived or an odour so weak that it cannot be easily characterised or described.  

1

Slight

Identified odour, slight

2

Moderate

Identified odour, moderate

3

Strong

Identified odour, strong

4

Extreme

Severe odour

Monitoring Schedule for the Reporting Month

The schedule for odour patrol during the reporting period is provided in Annex C.

Results and Observations

The odour monitoring results are summarised and provided in Table 2.7 and Annex D4, respectively.

Table 2.7        Summary of Odour Monitoring Results in the Reporting Period

Odour Checkpoints

Odour Intensity Class (Range)

Action Level

Limit Level

 

 

 

 

OP1

0 – 1

Odour intensity ≥ Class 2 recorded

Odour intensity ≥ Class 3 recorded on 2 consecutive patrol

OP2

0 – 1

OP3

0 – 1

OP4

0 – 1

OP5

0 – 1

OP6

0 – 1

OP7

0 – 1

OP8

0 – 1

OP9

0 – 1

OP10

0 – 1

OP11

0 – 1

 

 

OP12

0

 

 

OP13

0

 

 

OP14

0

 

 

OP15

0

 

 

OP16

0

 

 

OP17

0

 

 

Notes:

(a)    Reduction of monitoring frequency will be subject to the monitoring results to demonstrate environmentally acceptable performance.

The potential odour sources in the reporting period included the construction works, generator, slurry truck, excavator, dead body of wild animal, site vehicles, waste from tripping area and vegetation at SENTX, as well as nearby operations of the Leachate Treatment Plant and Town Gas Plant.

All the odour monitoring results were below the Action and Limit Levels in the reporting period.  No action is thus required to be undertaken in accordance with the Event and Action Plan presented in Annex D2.

2.1.3                          Thermal Oxidiser, Landfill Gas Flare and Landfill Gas Generator Stack Emission Monitoring

Monitoring Requirements and Equipment

According to the updated EM&A Manual of the Project, the performance of the thermal oxidiser, landfill gas flare and landfill gas generator was monitored when they are in operation. Gas samples were collected from the stack of the thermal oxidizer, landfill gas flare and landfill gas generator for laboratory analysis for NO2, CO, SO2, Benzene and Vinyl chloride and in-situ analysis for exhaust gas velocity at monthly interval. The operating conditions of the thermal oxidiser, landfill gas flare and landfill gas generator were also monitored continuously.

The Limit Levels for stack emission of the thermal oxidiser, landfill gas flare and landfill gas generator are provided in Tables 2.8 – 2.10 below.

Table 2.8        Limit Levels for Stack Emission of the Thermal Oxidiser

Parameters

Limit Level

NO2

1.58 gs-1

CO

0.53 gs-1

SO2

0.07 gs-1

Benzene

3.01 x 10-2 gs-1

Vinyl chloride

2.23 x 10-3 gs-1

Gas combustion temperature

850oC (minimum)

Exhaust gas exit temperature

443K (minimum) (a)

Exhaust gas velocity

7.5 ms-1 (minimum) (a)

Note:

(a)   Level under full load condition.

 

Table 2.9        Limit Levels for Stack Emission of the Landfill Gas Flare

Parameters

Limit Level

NO2

0.97 gs-1

CO

2.43 gs-1

SO2

0.22 gs-1

Benzene

4.14 x 10-4 gs-1

Vinyl Chloride

2.60 x 10-4 gs-1

Gas combustion temperature

815oC (minimum)

Exhaust gas exit temperature

923 K (minimum) (a)

Exhaust gas velocity

9.0 m s-1 (minimum) (a)

Note:

(a)   Level under full load condition.

 

Table 2.10      Limit Levels for Stack Emission of the Landfill Gas Generator

Parameters

Limit Level

NO2

1.91 gs-1

CO

2.48 gs-1

SO2

0.528 gs-1

Benzene

2.47 x 10-4 gs-1

Vinyl chloride

1.88 x 10-5 gs-1

Gas combustion temperature

450oC (minimum)

Exhaust gas exit temperature

723K (minimum) (a)

Exhaust gas velocity

30.0 ms-1 (minimum) (a)

Note:

(a)   Level under full load condition.

 

Gas samples were collected from the centroid of the stack with stainless steel sampling probe, into inert sample containers (i.e. Canister and Tedlar Bag) and transferred to ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066) laboratory within 24 hours of collection for direct analysis on a gas chromatography within 48 hours after collection.  The flue gas velocity of the gas stream at the exhaust of thermal oxidize was determined by S-Pitot tube during the emission sampling. 

The stack emission monitoring programme and monitoring locations are summarised in Table 2.11 and illustrated in Figure 2.1, respectively.

Table 2.11      Thermal Oxidiser, Landfill Gas Flare and Landfill Gas Generator Stack Emission Monitoring Details

Monitoring Location

Parameter

Frequency

Monitoring Date

Stack of Thermal Oxidiser

Laboratory analysis for

·     NO2

·     CO

·     SO2

·     Benzene

·     Vinyl chloride

In-situ analysis for

·     Exhaust gas velocity

Monthly for the first 12 months of operation and thereafter at quarterly intervals

12 Jan 2022,

11 Feb 2022,

7 Mar 2022,

11 Apr 2022,

16 May 2022,

16 Jun 2022,

18 Jul 2022,

8 Aug 2022,

15 Sep 2022,

17 Oct 2022,

17 Nov 2022,

13 Dec 2022

Laboratory analysis for

·        Non-methane organic compounds

Quarterly for the 1st  year of operation (b)

11 Feb 2022,

16 May 2022,

8 Aug 2022,

17 Nov 2022

Laboratory analysis for

·        Ammonia

Quarterly

11 Feb 2022,

16 May 2022,

8, 15 Aug 2022

17 Nov 2022

·     Gas combustion temperature

·     Exhaust temperature

·     Exhaust gas velocity (a)

Continuously

1 Jan – 31 Dec 2022

Stack of Landfill Gas Flare

Laboratory analysis for

·     NO2

·     CO

·     SO2

·     Benzene

·     Vinyl chloride

In-situ analysis for

·      Exhaust gas velocity

Monthly for the first 12 months of operation and thereafter at quarterly intervals

12 Jan 2022,

11 Feb 2022,

8 Mar 2022,

11 Apr 2022,

17 May 2022,

17 Jun 2022,

12 Jul 2022,

9 Aug 2022,

16 Sep 2022,

14 Oct 2022,

17 Nov 2022,

13 Dec 2022

Laboratory analysis for

·        Non-methane organic compounds

Quarterly for the 1st year of operation (b)

11 Feb 2022,

17 May 2022,

9 Aug 2022,

17 Nov 2022

·     Gas combustion temperature

·     Exhaust temperature

·     Exhaust gas velocity (a)

Continuously

1 Oct – 31 Dec 2022

Stack of Landfill Gas Generator

Laboratory analysis for

·     NO2

·     CO

·     SO2

·     Benzene

·     Vinyl chloride

In-situ analysis for

·        Exhaust gas velocity

Monthly for the first 12 months of operation and thereafter at quarterly intervals

12 Jan 2022,

11 Feb 2022,

8 Mar 2022,

12 Apr 2022,

16 May 2022,

16 Jun 2022,

12 Jul 2022,

9 Aug 2022,

15 Sep 2022,

14 Oct 2022,

18 Nov 2022 (c)

Laboratory analysis for

·        Non-methane organic compounds

Quarterly for the 1st  year of operation (b)

11 Feb 2022,

16 May 2022,

9 Aug 2022,

18 Nov 2022

·     Exhaust temperature

·     Exhaust gas velocity (a)

Continuously

1 Oct – 31 Dec 2022

Note:

(a)     The exhaust gas velocity will be calculated based on the cross-section area of the stack and continuous monitored gas flow and combustion temperature data.

(b)     The monitoring results will be reviewed towards the end of the first year of operation to determine if monitoring of this parameter can be terminated upon agreement by the EIAO Authority, IEC and Project Proponent.

(c)     The Landfill Gas Generator was under maintenance in December 2022.

 

Monitoring Schedule for the Reporting Month

The schedule for thermal oxidizer, landfill gas flare and landfill gas generator stack emission monitoring during the reporting period is provided in Annex C.  The stack emission monitoring for landfill gas generator was attempted on 14 December 2022 and 28 December 2022. However, sampling of the landfill gas generator stack emission was unable to be carried out in December 2022 as the landfill gas generator was under maintenance.

Results and Observations

The thermal oxidizer, landfill gas flare and landfill gas generator stack emission monitoring results and detailed continuous monitoring results are summarised in Tables 2.12 - 2.14 and provided in Annex D5, respectively.

Table 2.12      Summary of Thermal Oxidiser Stack Emission Monitoring in the Reporting Period

 

Parameters

Monitoring Results (Range in Bracket)

Limit Level

 

 

January 2022

 

 

NO2

0.38 gs-1

1.58 gs-1

 

 

CO

0.047 gs-1

0.53 gs-1

 

 

SO2

<0.015 gs-1

0.07 gs-1

 

 

Benzene

<4 x 10-5 gs-1

3.01 x 10-2 gs-1

 

 

Vinyl chloride

<3 x 10-5 gs-1

2.23 x 10-3 gs-1

 

 

Gas combustion temperature

972oC (952oC - 994oC)

850oC (minimum)

 

 

Exhaust gas exit temperature

1,237K (1,218K – 1,265K)

443K (minimum) (a)

 

 

Exhaust gas velocity

9.9 ms-1 (b)

7.5 ms-1 (minimum) (a)

 

 

February 2022

 

 

NO2

1.17 gs-1

1.58 gs-1

 

 

CO

0.06 gs-1

0.53 gs-1

 

 

SO2

0.02 gs-1

0.07 gs-1

 

 

Benzene

<3 x 10-5 gs-1

3.01 x 10-2 gs-1

 

 

Vinyl chloride

<3 x 10-5 gs-1

2.23 x 10-3 gs-1

 

 

Non-methane Organic Carbons

3.6 x 10-3 gs-1

-

 

 

Ammonia

6.52 x 10-2 gs-1

- (c)

 

 

Gas combustion temperature

973oC (958oC – 1,013oC)

850oC (minimum)

 

 

Exhaust gas exit temperature

1,230K (1,219K – 1,241K)

443K (minimum) (a)

 

 

Exhaust gas velocity

9.9 ms-1 (b)

7.5 ms-1 (minimum) (a)

 

 

March 2022

 

 

NO2

1.54 gs-1

1.58 gs-1

 

 

CO

0.04 gs-1

0.53 gs-1

 

 

SO2

<0.01 gs-1

0.07 gs-1

 

 

Benzene

<3 x 10-5 gs-1

3.01 x 10-2 gs-1

 

 

Vinyl chloride

<3 x 10-5 gs-1

2.23 x 10-3 gs-1

 

 

Gas combustion temperature

979oC (959oC – 1,035oC)

850oC (minimum)

 

 

Exhaust gas exit temperature

957K (941K – 1,003K)

443K (minimum) (a)

 

 

Exhaust gas velocity

9.1 ms-1 (b)

7.5 ms-1 (minimum) (a)

 

 

April 2022

 

 

NO2

0.63 gs-1

1.58 gs-1

 

 

CO

<0.01 gs-1

0.53 gs-1

 

 

SO2

<0.01 gs-1

0.07 gs-1

 

 

Benzene

<6 x 10-4 gs-1

3.01 x 10-2 gs-1

 

 

Vinyl chloride

<2 x 10-5 gs-1

2.23 x 10-3 gs-1

 

 

Gas combustion temperature

954oC (920oC – 980oC)

850oC (minimum)

 

 

Exhaust gas exit temperature

1,232K (1,200K – 1,325K)

443K (minimum) (a)

 

 

Exhaust gas velocity

6.6 ms-1 (b)

7.5 ms-1 (minimum) (a)

 

 

May 2022

 

 

NO2

0.11 gs-1

1.58 gs-1

 

 

CO

<0.02 gs-1

0.53 gs-1

 

 

SO2

0.06 gs-1

0.07 gs-1

 

 

Benzene

<3 x 10-5 gs-1

3.01 x 10-2 gs-1

 

 

Vinyl chloride

<4 x 10-5 gs-1

2.23 x 10-3 gs-1

 

 

Non-Methane Organic Carbons

0.0048 gs-1

-

 

 

Ammonia (NH3)

0.01 gs-1

-(c)

 

 

Gas combustion temperature

934oC (901oC – 949oC)

850oC (minimum)

 

 

Exhaust gas exit temperature

1,201K (1,182K – 1,216K)

443K (minimum) (a)

 

 

Exhaust gas velocity

11 ms-1 (b)

7.5 ms-1 (minimum) (a)

 

 

June 2022

 

 

NO2

0.39 gs-1

1.58 gs-1

 

 

CO

<0.01 gs-1

0.53 gs-1

 

 

SO2

<0.01 gs-1

0.07 gs-1

 

 

Benzene

<2 x 10-5 gs-1

3.01 x 10-2 gs-1

 

 

Vinyl chloride

<2 x 10-5 gs-1

2.23 x 10-3 gs-1

 

 

Gas combustion temperature

926oC (915oC – 936oC)

850oC (minimum)

 

 

Exhaust gas exit temperature

1,176K (1,148K – 1,206K)

443K (minimum) (a)

 

 

Exhaust gas velocity

9.0 ms-1 (b)

7.5 ms-1 (minimum) (a)

 

July 2022

NO2

0.89 gs-1

1.58 gs-1

CO

<0.01 gs-1

0.53 gs-1

SO2

<0.01 gs-1

0.07 gs-1

Benzene

<2.1 x 10-4 gs-1

3.01 x 10-2 gs-1

Vinyl chloride

<2 x 10-5 gs-1

2.23 x 10-3 gs-1

Gas combustion temperature

925oC (918oC – 934oC)

850oC (minimum)

Exhaust gas exit temperature

1,112K (1,162K – 1,175K)

443K (minimum) (a)

Exhaust gas velocity

9.7 ms-1 (b)

7.5 ms-1 (minimum) (a)

August 2022

NO2

0.86 gs-1

1.58 gs-1

CO

<0.01 gs-1

0.53 gs-1

SO2

<0.02 gs-1

0.07 gs-1

Non-Methane Organic Carbons

0.0055 gs-1

-

Benzene

<3 x 10-5 gs-1

3.01 x 10-2 gs-1

Vinyl chloride

<2 x 10-5 gs-1

2.23 x 10-3 gs-1

0.232 gs-1Ammonia

0.86 gs-1

-(c)

Gas combustion temperature

923oC (880oC – 933oC)

850oC (minimum)

Exhaust gas exit temperature

1,231K (1,181K – 1,241K)

443K (minimum) (a)

Exhaust gas velocity

9.3 ms-1 (b)

7.5 ms-1 (minimum) (a)

September 2022

NO2

0.38 gs-1

1.58 gs-1

CO

<0.01 gs-1

0.53 gs-1

SO2

<0.01 gs-1

0.07 gs-1

Benzene

<2 x 10-4 gs-1

3.01 x 10-2 gs-1

Vinyl chloride

<1.3 x 10-4 gs-1

2.23 x 10-3 gs-1

Ammonia

0.0414 gs-1

-(c)

Gas combustion temperature

924oC (912oC – 932oC)

850oC (minimum)

Exhaust gas exit temperature

1,238K (1,225K – 1,248K)

443K (minimum) (a)

Exhaust gas velocity

11.2 ms-1 (b)

7.5 ms-1 (minimum) (a)

October 2022

NO2

0.39 gs-1

1.58 gs-1

CO

<0.01 gs-1

0.53 gs-1

SO2

0.04 gs-1

0.07 gs-1

Benzene

<2 x 10-4 gs-1

3.01 x 10-2 gs-1

Vinyl chloride

<1.3 x 10-4 gs-1

2.23 x 10-3 gs-1

Gas combustion temperature

926oC (901oC – 937oC)

850oC (minimum)

Exhaust gas exit temperature

1,248K (1,147K – 1,593K)

443K (minimum) (a)

Exhaust gas velocity

11.9 ms-1 (b)

7.5 ms-1 (minimum) (a)

November 2022

NO2

0.28 gs-1

1.58 gs-1

CO

<0.01 gs-1

0.53 gs-1

SO2

0.07 gs-1

0.07 gs-1

Non-Methane Organic Carbons

<1.0 x 10-4 gs-1

-

Benzene

<1.0 x 10-4 gs-1

3.01 x 10-2 gs-1

Vinyl chloride

<0.002 gs-1

2.23 x 10-3 gs-1

Ammonia

0.0423 gs-1

-(c)

Gas combustion temperature

946oC (906oC – 977oC)

850oC (minimum)

Exhaust gas exit temperature

1,224K (1,125K – 1,270K)

443K (minimum) (a)

Exhaust gas velocity

6.8 ms-1 (b)

7.5 ms-1 (minimum) (a)

December 2022

NO2

1.06 gs-1

1.58 gs-1

CO

<0.01 gs-1

0.53 gs-1

SO2

0.03 gs-1

0.07 gs-1

Benzene

<1.0 x 10-4 gs-1

3.01 x 10-2 gs-1

Vinyl chloride

<1.0 x 10-4 gs-1

2.23 x 10-3 gs-1

923oC (909oC – 934oC)Gas combustion temperature

923oC (909oC – 934oC)

850oC (minimum)

Exhaust gas exit temperature

1,196K (1,145K – 1,283K)

443K (minimum) (a)

Exhaust gas velocity

7.9 ms-1 (b)

7.5 ms-1 (minimum) (a)

Note:

(a) Level under full load condition.

(b) The exhaust gas velocity was calculated based on the cross-section area of the stack and the gas flow and combustion temperature data measured during the stack emission monitoring. The limit level was not applicable as the stack was not operated under full load condition.

(c) The emission limit for ammonia is under review and will be supplemented in subsequent revision.

 

GTable 2.13      Summary of Landfill Gas Flare Stack Emission Monitoring in the Reporting Period

Parameters

Monitoring Results (Range in Bracket)

Limit Level

January 2022

NO2

Flare 1: <0.01 gs-1

Flare 2: <0.01 gs-1

0.97 gs-1

CO

Flare 1: 0.032 gs-1

Flare 2: 0.04 gs-1

2.43 gs-1

SO2

Flare 1: 0.09 gs-1

Flare 2: 0.10 gs-1

0.22 gs-1

Benzene

Flare 1: 1.3 x 10-5 gs-1

Flare 2: 1.6 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

Flare 1: <1.1 x 10-5 gs-1

Flare 2: <1.3 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 1,010oC (854oC – 1,171oC)

Flare 2: 916oC (820oC – 1,171oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,144K (1,023K – 1,223K)

Flare 2: 1,116K (1,045K – 1,283K)

923 K (minimum) (a)

Exhaust gas velocity

Flare 1: 4.3 ms-1 (b)

Flare 2: 2.0 ms-1 (b)

9.0 m s-1 (minimum) (a)

February 2022

NO2

<0.01 gs-1

0.97 gs-1

CO

0.027 gs-1

2.43 gs-1

SO2

0.110 gs-1

0.22 gs-1

Benzene

5.1 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.1 x 10-5 gs-1

2.60 x 10-4 gs-1

Non-methane Organic Carbons

4.1 x 10-3 gs-1

-

Gas combustion temperature

Flare 1: 893oC (816oC – 995oC)

Flare 2: 857oC (830oC – 924oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,143K (1,083K – 1,213K)

Flare 2: 1,072K (1,015K – 1,123K)

923 K (minimum) (a)

Exhaust gas velocity

4.4 ms-1 (b)

9.0 m s-1 (minimum) (a)

March 2022

NO2

0.02 gs-1

0.97 gs-1

CO

0.056 gs-1

2.43 gs-1

SO2

0.007 gs-1

0.22 gs-1

Benzene

<1.2 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.0 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 911oC (830oC – 990oC)

Flare 2: 854oC (820oC – 890oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,141K (1,073K – 1,223K)

Flare 2: 1,077K (1,033K – 1,123K)

923 K (minimum) (a)

Exhaust gas velocity

3.9 ms-1 (b)

9.0 m s1 (minimum) (a)

April 2022

NO2

0.01 gs-1

0.97 gs-1

CO

0.04 gs-1

2.43 gs-1

SO2

0.06 gs-1

0.22 gs-1

Benzene

<1.8 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.5 x 10-5 gs-1

2.60 x 10-4 gs-1

Non-Methane Organic Carbons

<0.0014 gs-1

-

Gas combustion temperature

Flare 1: 890oC (820oC – 990oC)

Flare 2: 860oC (820oC – 890oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 999K (943K – 1,073K)

Flare 2: 1,094K (1,043K – 1,133K)

923 K (minimum) (a)

May 2022

NO2

0.01 gs-1

0.97 gs-1

CO

0.04 gs-1

2.43 gs-1

SO2

0.06 gs-1

0.22 gs-1

Benzene

<1.8 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.5 x 10-5 gs-1

2.60 x 10-4 gs-1

Non-Methane Organic Carbons

<0.0014 gs-1

-

Gas combustion temperature

Flare 1: 890oC (820oC – 990oC)

Flare 2: 860oC (820oC – 890oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 999K (943K – 1,073K)

Flare 2: 1,094K (1,043K – 1,133K)

923 K (minimum) (a)

Exhaust gas velocity

2.7 ms-1 (b)

9.0 m s-1 (minimum) (a)

June 2022

NO2

0.03 gs-1

0.97 gs-1

CO

0.098 gs-1

2.43 gs-1

SO2

0.11 gs-1

0.22 gs-1

Benzene

<3.6 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.6 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 887oC (822oC – 970oC)

Flare 2: 867oC (830oC – 930oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,043K (983K – 1,143K)

Flare 2: 1,093K (1,043K – 1,183K)

923 K (minimum) (a)

Exhaust gas velocity

8.3 ms-1 (b)

9.0 m s-1 (minimum) (a)

July 2022

NO2

<0.01 gs-1

0.97 gs-1

CO

0.53 gs-1

2.43 gs-1

SO2

0.01 gs-1

0.22 gs-1

Benzene

<1.8 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.4 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 901oC (822oC – 955oC)

Flare 2: 858oC (824oC – 930oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,035K (963K – 1,083K)

Flare 2: 1,093K (1,061K – 1,163K)

923 K (minimum) (a)

Exhaust gas velocity

6.5 ms-1 (b)

9.0 m s-1 (minimum) (a)

August 2022

NO2

<0.02 gs-1

0.97 gs-1

CO

0.83 gs-1

2.43 gs-1

SO2

0.12 gs-1

0.22 gs-1

Non-Methane Organic Carbons

<0.002 gs-1

-

Benzene

<2.5 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<2.0 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 890oC (826oC – 966oC)

Flare 2: 846oC (820oC – 890oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,110K (993K – 1,248K)

Flare 2: 1,061K (1,023K – 1,103K)

923 K (minimum) (a)

Exhaust gas velocity

8.9 ms-1 (b)

9.0 m s-1 (minimum) (a)

September 2022

NO2

<0.02 gs-1

0.97 gs-1

CO

<0.01 gs-1

2.43 gs-1

SO2

<0.01 gs-1

0.22 gs-1

Benzene

<1.23 x 10-4 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<9.8 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 866oC (820oC – 944oC)

Flare 2: 861oC (821oC – 948oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,046K (987K – 1,127K)

Flare 2: 1,080K (1,046K – 1,127K)

923 K (minimum) (a)

Exhaust gas velocity

8.9 ms-1 (b)

9.0 m s-1 (minimum) (a)

October 2022

NO2

0.013 gs-1

0.97 gs-1

CO

<0.01 gs-1

2.43 gs-1

SO2

0.26 gs-1

0.22 gs-1

Benzene

<1.22 x 10-4 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<9.8 x 10-5 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 908oC (820oC – 990oC)

Flare 2: 872oC (820oC – 910oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,060K (988K – 1,183K)

Flare 2: 1,076K (993K – 1,133K)

923 K (minimum) (a)

Exhaust gas velocity

6.5 ms-1 (b)

9.0 m s-1 (minimum) (a)

November 2022

NO2

<0.02 gs-1

0.97 gs-1

CO

<0.01 gs-1

2.43 gs-1

SO2

1.27 gs-1

0.22 gs-1

Non-Methane Organic Carbons

<1.22 x 10-4 gs-1

-

Benzene

<9.8 x 10-5 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<0.002 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 856oC (820oC – 890oC)

Flare 2: 854oC (820oC – 890oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,064K (1,030K – 1,093K)

Flare 2: 1,077K (1,033K – 1,123K)

923 K (minimum) (a)

Exhaust gas velocity

8.9 ms-1 (b)

9.0 m s-1 (minimum) (a)

December 2022

NO2

0.03 gs-1

0.97 gs-1

CO

0.783 gs-1

2.43 gs-1

SO2

0.16 gs-1

0.22 gs-1

Benzene

6.61 x 10-4 gs-1

4.14 x 10-4 gs-1

Vinyl chloride

<1.35 x 10-4 gs-1

2.60 x 10-4 gs-1

Gas combustion temperature

Flare 1: 854oC (850oC – 910oC)

Flare 2: 860oC (830oC – 890oC)

815oC (minimum)

Exhaust gas exit temperature

Flare 1: 1,075K (1,033K – 1,153K)

Flare 2: 1,085K (1,033K – 1,123K)

923 K (minimum) (a)

Exhaust gas velocity

12.8 ms-1 (b)

9.0 m s-1 (minimum) (a)

Note:

(a) Level under full load condition.

(b) The exhaust gas velocity was calculated based on the cross-section area of the stack and the gas flow and combustion temperature data measured during the stack emission monitoring. The limit level was not applicable as the stack was not operated under full load condition.

 

 

Table 2.14      Summary of Landfill Gas Generator Stack Emission Monitoring in the Reporting Period

 

Parameters

Monitoring Results (Range in Bracket)

Limit Level

 

 

January 2022

 

 

NO2

0.008 gs-1

1.91 gs-1

 

 

CO

0.050 gs-1

2.48 gs-1

 

 

SO2

0.009 gs-1

0.528 gs-1

 

 

Benzene

2 x 10-6 gs-1

2.47 x 10-4 gs-1

 

 

Vinyl chloride

<1.3 x 10-6 gs-1

1.88 x 10-5 gs-1

 

 

Exhaust gas exit temperature

843K (835K – 853K)

723K (minimum) (a)

 

 

Exhaust gas velocity

7.8 ms-1 (b)

30.0 ms-1 (minimum) (a)

 

 

February 2022

 

 

NO2

0.016 gs-1

1.91 gs-1

 

 

CO

0.056 gs-1

2.48 gs-1

 

 

SO2

0.002 gs-1

0.528 gs-1

 

 

Benzene

<3 x 10-6 gs-1

2.47 x 10-4 gs-1

 

 

Vinyl chloride

<2 x 10-6 gs-1

1.88 x 10-5 gs-1

 

 

Non-methane Organic Carbons

2 x 10-4 gs-1

-

 

 

Exhaust gas exit temperature

843K (836K – 847K)

723K (minimum) (a)

 

 

Exhaust gas velocity

11.9 ms-1 (b)

30.0 ms-1 (minimum) (a)

 

 

March 2022

 

 

NO2

0.022 gs-1

1.91 gs-1

 

 

CO

0.06 gs-1

2.48 gs-1

 

 

SO2

<0.001 gs-1

0.528 gs-1

 

 

Benzene

<2 x 10-6 gs-1

2.47 x 10-4 gs-1

 

 

Vinyl chloride

<1.9 x 10-6 gs-1

1.88 x 10-5 gs-1

 

 

Exhaust gas exit temperature

845K (840K – 850K)

723K (minimum) (a)

 

 

Exhaust gas velocity

7.8 ms-1 (b)

30.0 ms-1 (minimum) (a)

 

April 2022

 

 

NO2

0.25 gs-1

1.91 gs-1

 

 

CO

0.094 gs-1

2.48 gs-1

 

 

SO2

<0.001 gs-1

0.528 gs-1

 

 

Benzene

<3 x 10-6 gs-1

2.47 x 10-4 gs-1

 

 

Vinyl chloride

<2.3 x 10-6 gs-1

1.88 x 10-5 gs-1

 

 

Exhaust gas exit temperature

849K (841K – 870K)

723K (minimum) (a)

 

 

Exhaust gas velocity

13.3 ms-1 (b)

30.0 ms-1 (minimum) (a)

 

 

May 2022

 

 

NO2

0.01 gs-1

1.91 gs-1

 

 

CO

0.099 gs-1

2.48 gs-1

 

 

SO2

0.004 gs-1

0.528 gs-1

 

 

Benzene

<3 x 10-6 gs-1

2.47 x 10-4 gs-1

 

 

Vinyl chloride

<2.4 x 10-6 gs-1

1.88 x 10-5 gs-1

 

 

Non-Methane Organic Carbons

3 x 10-4 gs-1

-

 

 

Exhaust gas exit temperature

851K (845K – 857K)

723K (minimum) (a)

 

 

Exhaust gas velocity

11.6 ms-1 (b)

30.0 ms-1 (minimum) (a)

 

 

June 2022

 

 

NO2

0.008 gs-1

1.91 gs-1

 

 

CO

0.043 gs-1

2.48 gs-1

 

 

SO2

<0.001 gs-1

0.528 gs-1

 

 

Benzene

<4.0 x 10-6 gs-1

2.47 x 10-4 gs-1

 

 

Vinyl chloride

<2.2 x 10-6 gs-1

1.88 x 10-5 gs-1

 

 

Exhaust gas exit temperature

861K (848K – 879K)

723K (minimum) (a)

 

 

Exhaust gas velocity

9.7 ms-1 (b)

30.0 ms-1 (minimum) (a)

 

July 2022

NO2

0.01 gs-1

1.91 gs-1

CO

0.28 gs-1

2.48 gs-1

SO2

0.003 gs-1

0.528 gs-1

Benzene

<8.0 x 10-6 gs-1

2.47 x 10-4 gs-1

Vinyl chloride

<1.8 x 10-6 gs-1

1.88 x 10-5 gs-1

Exhaust gas exit temperature

864K (848K – 893K)

723K (minimum) (a)

Exhaust gas velocity

11.2 ms-1 (b)

30.0 ms-1 (minimum) (a)

August 2022

NO2

0.04 gs-1

1.91 gs-1

CO

0.622 gs-1

2.48 gs-1

SO2

0.015 gs-1

0.528 gs-1

Non-Methane Organic Carbons

0.0012 gs-1

-

Benzene

<8.7 x 10-5 gs-1

2.47 x 10-4 gs-1

Vinyl chloride

<2.1 x 10-6 gs-1

1.88 x 10-5 gs-1

Exhaust gas exit temperature

861K (855K – 868K)

723K (minimum) (a)

Exhaust gas velocity

9.3 ms-1 (b)

30.0 ms-1 (minimum) (a)

September 2022

NO2

0.07 gs-1

1.91 gs-1

CO

0.75 gs-1

2.48 gs-1

SO2

0.008 gs-1

0.528 gs-1

Benzene

<1.92 x 10-4 gs-1

2.47 x 10-4 gs-1

Vinyl chloride

<9.6 x 10-6 gs-1

1.88 x 10-5 gs-1

Exhaust gas exit temperature

859K (845K – 880K)

723K (minimum) (a)

Exhaust gas velocity

10.2 ms-1 (b)

30.0 ms-1 (minimum) (a)

October 2022

NO2

0.08 gs-1

1.91 gs-1

CO

0.56 gs-1

2.48 gs-1

SO2

0.006 gs-1

0.528 gs-1

Benzene

<1.12 x 10-4 gs-1

2.47 x 10-4 gs-1

Vinyl chloride

<9.7 x 10-6 gs-1

1.88 x 10-5 gs-1

Exhaust gas exit temperature

ENGA: 866K (851K – 893K)

ENGB : 860K (847K – 867K)

723K (minimum) (a)

Exhaust gas velocity

10.3 ms-1 (b)

30.0 ms-1 (minimum) (a)

November 2022

NO2

0.01 gs-1

1.91 gs-1

CO

0.429 gs-1

2.48 gs-1

SO2

<0.001 gs-1

0.528 gs-1

Non-Methane Organic Carbons

<1.6 x 10-5 gs-1

-

Benzene

<1.28 x 10-5 gs-1

2.47 x 10-4 gs-1

Vinyl chloride

<3.0 x 10-4 gs-1

1.88 x 10-5 gs-1

Exhaust gas exit temperature

ENGA: 904K (890K – 955K)

ENGB : 898K (880K – 917K)

723K (minimum) (a)

Exhaust gas velocity

11.6 ms-1 (b)

30.0 ms-1 (minimum) (a)

December 2022

NO2

-

1.91 gs-1

CO

-

2.48 gs-1

SO2

-

0.528 gs-1

Benzene

-

2.47 x 10-4 gs-1

Vinyl chloride

-

1.88 x 10-5 gs-1

Exhaust gas exit temperature

ENGA: -

ENGB : -

723K (minimum) (a)

Exhaust gas velocity

-

30.0 ms-1 (minimum) (a)

Note:

(a) Level under full load condition.

(b) The exhaust gas velocity was calculated based on the cross-section area of the stack and the gas flow and combustion temperature data measured during the stack emission monitoring. The limit level was not applicable as the stack was not operated under full load condition.

(c) The Landfill Gas Generator was under maintenance in December 2022.

Limit Levels exceedances were recorded for landfill gas flare stack emission (SO2 and Benezene) in the reporting period and actions in accordance with the Event and Action Plan presented in Annex D2 were undertaken. Investigation of the Limit Levels exceedances was conducted and the investigation reports are presented in Annex D7.

Based on the investigation conducted for the monitoring event with potential Limit Levels exceedance with the Contractor and the IEC, the landfill gas flare stack emission (SO2) exceedance on 14 October 2022 and 17 November 2022 and the landfill gas flare stack emission (Benzene) exceedance on 13 December 2022 were considered Project-related.

The Contractor was reminded to implement all relevant mitigation measures for the construction and operation works and maintain good site practice. The ET will keep track on the monitoring data and ensure Contractor’s compliance of the environmental requirements.

2.1.4                          Ambient VOCs, Ammonia and H2S Monitoring

Monitoring Requirements and Equipment

According to the updated EM&A Manual of the Project, ambient VOCs, ammonia and H2S monitoring was carried out at the four designated locations along the site boundary (i.e. AM1, AM2, AM3 and AM4) during the operation/restoration phase, at quarterly interval.

The Limit Levels for ambient VOCs, ammonia and H2S monitoring is provided in Table 2.15 below.

Table 2.15      Limit Levels for Ambient VOCs, Ammonia and H2S Monitoring

Parameters

Limit Level (µg m-³)

Methane

NA (a)

Ammonia

180

H2S

42

Dichlorodifluoro-methane

NA (a)

Vinyl Chloride

26

Methanol

2,660

Ethanol

19,200

Dimethylsulphide

8

Carbon Disulphide

150

Methylene Chloride

3,530

Chloroform

99

Methyl propionate

353

Butan-2-ol

667

1.1.1-Trichloroethane

5,550

1.2-Dichloroethane

210

Benzene

33

Carbon Tetrachloride

64

Dipropyl ether

NA (a)

Heptane

2,746

Trichloroethylene

5,500

Ethyl propionate

29

Methyl butanoate

30

Methanethiol

10

Toluene

1,244

Ethyl butanoate

71

Propyl benzene

19

Octane

7,942

Propyl propionate

276

1.2-Dibromoethane (EDB)

39

Butyl acetate

7,240

Tetrachloroethylene

1,380

Ethyl benzene

738

Nonane

11,540

Ethanethiol

13

Decanes

3,608

Limonene

212

Butyl benzene

47

Undecane

5,562

Butanethiol

4

Terpenes

NA (a)

Xylenes

534

Dichlorobenzene

120

Notes:

(a)    No relevant WHO/USEPA/CARB’s ambient criteria, odour thresholds and WEL available.

 

VOCs

Ambient air samples were drawn into the pre-cleaned and vacuum canister directly when the valve of the flow controller (with preset flow rate) was opened.  After sampling, the valve will be closed manually and the canister with VOCs gas samples were transported for laboratory analysis.

Methane

Pre-cleaned Tedlar bag was placed in the vacuum chamber.  Ambient air was collected in the Tedlar bag under the vacuum condition when the pump is switched on.  The Tedlar bag was filled up to 90% of total capacity to avoid leakage and bag deformation.  After sampling, pump is switched off and the valve of Tedlar bag was closed manually.  The air samples were transported back to laboratory for analysis.

Ammonia

Calibrated personal air pump was used to pump the air through a sulfuric acid-treated silica gel sorbent tube.  Gaseous ammonia in air was then trapped in the sorbent tube.  The tube was transported back to laboratory for analysis.

H2S

H2S in air is collected in mid-get impingers by aspirating a measured   volume of air through an alkaline suspension of cadmium hydroxide (as the absorbing solution).  The sulphide is precipitated as cadmium sulphide to prevent air oxidation of the sulphide.  Arabinogalactan is added to the cadmium hydroxide slurry prior to sampling to minimize photo-decomposition of the precipitated cadmium sulphide.  The solution is transported back to laboratory for analysis.

All air samples collected for laboratory analysis were transported to ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066) laboratory within 24 hours and analysed within 48 hours. 

The ambient VOCs, ammonia and H2S monitoring programme and monitoring locations are summarised in Table 2.16 and illustrated in Figure 2.1, respectively.

Table 2.16      Ambient VOCs, Ammonia and H2S Monitoring Details

Monitoring Station

Location

Parameter

Frequency

Monitoring Date

 

AM1

SENTX Site Boundary (North)

·     Methane

·     Ammonia

·     A suite of VOCs (a)

·     H2S

Quarterly

15 Feb 2022,

16 May 2022, 8 Aug 2022, 17 Nov 2022

 

AM2

SENTX Site Boundary (West, near DP3)

 

AM3

SENTX Site Boundary (West, near RC15)

 

AM4

SENTX Site Boundary (West, near EPD building)

 

Notes:

(a)  A suite of VOCs includes:

 

  • Trichloroethylene
  • Vinyl chloride
  • Methylene chloride
  • Chloroform
  • 1,2-dichloroethane
  • 1,1,1-trichloroethane
  • Carbon tetrachloride
  • Tetrachloroethylene
  • 1,2-dibromoethane
  • Benzene
  • Toluene
  • Carbon disulphide
  • Propyl benzene

·        Ethyl benzene

·        Butyl benzene

·        Xylenes

·        Decanes

·        Undecane

·        Limonene

·        Terpenes

·        Ethanol

·        Butan-2-ol

·        Dimethylsulphide

·        Methyl propionate

·        Ethyl propionate

·        Propyl propionate

·        Butyl acetate

·        Ethyl butanoate

·        Dichlorobenzene

·        Methyl butanoate

·        Dipropyl ether

·        Methanethiol

·        Ethanethiol

·        Butanethiol

·        Methanol

·        Heptanes

·        Octanes

·        Nonanes

·        Dichlorodifluoro-methane

·        Methane

Monitoring Schedule for the Reporting Month

The schedule for ambient VOCs, ammonia and H2S monitoring during the reporting period is provided in Annex C.

Results and Observations

The ambient VOCs, ammonia and H2S monitoring results are summarized in Tables 2.17 and provided in Annex D6.

Table 2.17      Summary of Ambient VOCs, Ammonia and H2S Monitoring Results in the Reporting Period

 

Parameters

Limit Level (µg m-³)

Monitoring Results (µg m-³) (Average)

AM1

AM2

AM3

AM4

Ammonia

180

20.25

15.50

16.75

17.25

H2S

42

14.5

14.5

14.5

14.5

Methane

NA (a)

0.0

0.0

0.0

0.0

1.1.1-Trichloroethane

5,550

0.8

0.8

0.8

0.8

1.2-Dibromoethane (EDB)

39

1.1

1.1

1.1

1.1

1.2-Dichloroethane

210

0.8

0.9

0.7

0.9

Benzene

33

1.1

1.0

0.8

1.0

Butan-2-ol

667

0.6

0.6

0.6

0.6

Butanethiol

4

<1.2

<1.2

<1.2

<1.2

Carbon Disulphide

150

0.9

0.7

3.3

1.1

Carbon Tetrachloride

64

0.8

0.8

0.7

0.8

Chloroform

99

<0.8

<0.8

<0.8

<0.8

Decanes

3,608

0.9

0.8

1.2

0.8

Dichlorobenzene

120

1.0

1.0

1.0

1.0

Dichlorodifluoro-methane

NA (a)

1.3

1.6

1.2

1.5

Dimethylsulphide

8

<0.3

<0.3

<0.3

<0.3

Dipropyl ether

NA (a)

0.8

0.8

0.8

0.8

Limonene

212

0.8

0.7

1.6

0.7

Ethanethiol

13

<0.6

<0.6

<0.6

<0.6

Ethanol

19,200

4.9

3.8

3.8

9.3

Ethyl butanoate

71

<1.0

<1.0

<1.0

<1.0

Ethyl propionate

29

<0.8

<0.8

<0.8

<0.8

Ethyl benzene

738

0.9

0.9

1.3

1.1

Heptane

2,746

<0.8

<0.8

<0.8

<0.8

Methanethiol

10

<0.4

<0.4

<0.4

<0.4

Methanol

2,660

17.9

12.2

12.5

25.3

Methyl butanoate

30

<0.8

<0.8

<0.8

<0.8

Methyl propionate

353

<0.7

<0.7

<0.7

<0.7

Methylene Chloride

3,530

3.0

3.8

3.0

4.3

Butyl acetate

76

<1.0

<1.0

<1.0

<1.2

Butyl benzene

47

<1.0

<1.0

<1.0

<1.0

Nonane

11,540

<0.9

<0.9

<0.9

<0.9

Propyl benzene

19

<0.8

<0.8

<0.8

<0.8

Octane

7,942

<0.9

<0.9

<0.9

<0.9

Propyl propionate

276

<1.0

<1.0

<1.0

<1.0

Terpenes

NA (a)

1.3

0.8

1.3

1.3

Tetrachloroethylene

1,380

<0.8

<0.8

<0.8

<0.8

Toluene

1,244

2.1

2.2

2.4

3.2

Trichloroethylene

5,500

<1.1

<1.1

<1.1

<1.1

Undecane

5,562

<1.2

<1.2

<1.3

<1.2

Vinyl Chloride

26

<0.3

<0.3

<0.3

<0.3

Xylenes

534

1.6

1.6

3.3

2.6

Notes:

(a)     No relevant WHO/USEPA/CARB’s ambient criteria and WEL available.

 

All ambient VOCs, ammonia and H2S monitoring results were below the Limit Levels in the reporting period.  No action is thus required to be undertaken in accordance with the Event and Action Plan presented in Annex D2.

2.2                               Noise Monitoring

2.2.1                          Monitoring Requirements and Equipment

According to the updated EM&A Manual of the Project, impact noise monitoring was conducted weekly at the monitoring location (i.e. NM1) to obtain one set of 30 minutes measurement between 07:00 and 19:00 hours on normal weekdays. 

The Action and Limit Levels for operational noise of the Project are provided in Table 2.18 below. 

Table 2.18      Action and Limit Levels for Operational Noise

Time Period

Action Level (a)

Limit Level (b)

07:00 – 19:00 hrs on all days

 

When one documented complaint is received from any one of the noise sensitive receivers (NSRs)

or

75 dB(A) recorded at the monitoring station

65 dB(A) at NSRs (c)

19:00 – 23:00 hrs on all days

 

65 dB(A) at NSRs (c)

23:00 – 07:00 hrs on all days

55 dB(A) at NSRs (c)

Notes:

(a)        75dB(A) along and at about 100m from the SENTX site boundary was set as the Action Level.

(b)        Limits specified in the GW-TM and IND-TM for construction and operational noise, respectively.

(c)        Limit Level only apply to operational noise without road traffic and construction activities noise.   

 

Noise monitoring was performed by ALS Technichem (HK) Pty Ltd (HOKLAS Registration No. 066) using a sound level meter placed at the designated monitoring station NM1 (see Figure 2.1) in accordance with the requirements stipulated in the updated EM&A Manual. Acoustic calibrator was deployed to check the sound level meter at a known sound pressure level.  Details of the deployed equipment are provided in Table 2.19.

Table 2.19      Noise Monitoring Details

Monitoring Station (1)

Location

Parameter

Frequency and Duration

Monitoring Dates

Equipment

NM1

SENTX Site Boundary (North)

Leq (30 min) measurement between 07:00 and 19:00 hours on normal weekdays

(Monday to Saturday)

Once per week for 30 mins during the operation period of the Project

7, 13, 19, 25, 31 Jan 2022

 

7, 14, 24 Feb 2022

 

2, 8, 14, 21, 28 Mar 2022

 

7, 13, 19, 25 Apr 2022

 

3, 10, 19, 25, 31 May 2022

 

6, 13, 20, 30 Jun 2022

 

6, 12, 18, 25 Jul 2022

 

1, 11, 17, 23, 29 Aug 2022

 

5, 13, 22, 28 Sep 2022

 

5, 10, 17, 24 Oct 2022

 

3, 9, 15, 21, 28 Nov 2022

 

5, 15, 21, 28 Dec 2022

Sound Level Meter:

 

B&K 2238 (S/N: 2285722)

 

Rion NL-52 (S/N: 00809405)

 

Rion NL-52 (S/N: 00921191)

 

Rion NL-52 (S/N: 00464681)

 

Rion NL-52 (S/N: 00142581)

 

Rion NL-31 (S/N: 00410247)

 

Acoustic Calibrator:

 

Calibrator:

Rion NC-74 (S/N: 34246492)

 

Rion NC-74 (S/N: 34657231)

 

Bruel & Kjaer 4231

(S/N: 2713428)

 

B&K 4231 (S&N: 2713428)

 

2.2.2                          Monitoring Schedule for the Reporting Period

The schedule for noise monitoring during the reporting period is provided in Annex C.

2.2.3                          Results and Observations

A total of 52 impact noise monitoring events were scheduled during the reporting period.  However, noise monitoring on 7 February 2022, 28 March 2022, 10 May 2022, 6 and 30 June 2022 and 11 August 2022 were cancelled due to adverse weather. The noise monitoring results are summarised in Table 2.20 and graphically presented in Annex E1.

Table 2.20      Summary of Operation Noise Monitoring Results in the Reporting Period

Month

Monitoring Station

Measured Noise Level Leq (30 min), dB(A)

Average

Range

Action and Limit Level

January 2022

NM1

51.4

49.4 – 53.4

75

February 2022

NM1

48.6

48.1 – 49.0

75

March 2022

NM1

48.6

45.9 – 51.3

75

April 2022

NM1

51.1

49.5 – 51.7

75

May 2022

NM1

51.0

49.3 – 54.7

75

June 2022

NM1

57.8

57.4 – 58.2

75

July 2022

NM1

52.9

51.5 – 54.4

75

August 2022

NM1

52.3

51.1 – 53.0

75

September 2022

NM1

51.0

48.1 – 54.5

75

October 2022

NM1

51.8

51.0 – 53.3

75

November 2022

NM1

50.8

48.1 – 52.7

75

December 2022

NM1

54.6

50.1 – 64.0

75

Major noise sources identified during the noise monitoring included noise from operations of SENTX, the existing SENT landfill and the TKO Area 137 Fill Bank, aircrafts and insects.

No exceedance of the Action and Limit Levels for operation noise monitoring was recorded in the reporting period.  No further mitigation measure was required in accordance with the Event and Action Plan presented in Annex E2.

2.3                               Water Quality Monitoring

2.3.1                          Surface Water Quality Monitoring

Monitoring Requirements and Equipment

According to the updated EM&A Manual of the Project, impact surface water quality monitoring was carried out at the three designated surface water discharge points (i.e. DP3, DP4 and DP6) at monthly intervals during operation/restoration phase to ensure that the SENTX will not cause adverse water quality impact.  Suspension of impact surface water quality monitoring at DP3 was approved under the Baseline Monitoring Report by EPD on 24 July 2019 until the actual commencement of construction works affecting DP3 in 2022.

The parameters as listed in Table 2.22 were determined by ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066).

The Action and Limit Levels of the surface water quality impact monitoring are provided in Table 2.21.

Table 2.21      Action and Limit Levels for Surface Water Quality

Parameters

 

Limit Level

DP4 & DP6

Ammoniacal-nitrogen

 

> 7.1 mg/L

COD

 

> 30 mg/L

SS

 

> 20 mg/L

The locations of the monitoring stations for the Project are shown in Figure 2.1.  All in situ monitoring instruments were checked, calibrated and certified by a laboratory accredited under HOKLAS or other international accreditation scheme before use, and subsequently re-calibrated at 3 monthly intervals throughout all stages of the surface water quality monitoring programme.  Calibration for a DO meter was carried out before measurement according to the instruction manual of the equipment model.  Details of the equipment used in the impact surface water quality monitoring works are provided in Table 2.22.

Table 2.22      Impact Surface Water Quality Monitoring Details

Monitoring Station

Location

Frequency

Monitoring Dates

Parameter

Equipment

DP4

Surface water discharge point DP4

Monthly

25 Jan 2022,

24 Feb 2022

21 Mar 2022, 25 Apr 2022,

25 May 2022,

24 Jun 2022,

25 Jul 2022,

23 Aug 2022,

22 Sep 2022,

24 Oct 2022,

21 Nov 2022,

21 Dec 2022

·    pH

·    Electrical conductivity (EC)

·    DO

·    SS

·    COD

·    BOD5

·    TOC

·    Ammoniacal–nitrogen

·    Nitrate-nitrogen

·    Nitrite–nitrogen

·    TKN

·    TN

·    Phosphate

·    Sulphate

·    Sulphide

·    Carbonate

·    Oil & Grease

 

·    Bicarbonate

·    Chloride

·    Sodium

·    Potassium

·    Calcium

·    Magnesium

·    Nickel

·    Manganese

·    Chromium

·    Cadmium

·    Copper

·    Lead

·    Iron

·    Zinc

·    Mercury

·    Boron

 

YSI Professional DSS (S/N: 15H103928)

 

YSI Professional DSS (S/N: 17B102764)

 

YSI Professional DSS (S/N: 17B100758)

 

 

DP6

Surface water discharge point DP6

Notes:

(a)    Impact surface water quality monitoring at DP3 was suspended from the monitoring event on 25 July 2019 until the actual commencement of construction works affecting DP3 in 2022.

 

 

 

Monitoring Schedule for the Reporting Period

The schedule for surface water quality monitoring during the reporting period is provided in Annex C.

Results and Observations

A total of twelve regular monitoring events for impact surface water quality monitoring were scheduled at all designated monitoring stations and three additional surface water quality monitoring event was scheduled during the reporting period.  However, sampling could not be carried out from January to April and from August to December 2022 due to insufficient flow. Details of impact water quality monitoring event are provided in Annex F1.

Limit Level exceedance (SS) was recorded for surface water quality impact monitoring on 25 May 2022 at DP4 and the exceedance was found to be project-related upon further investigation. Actions in accordance with the Event and Action Plan in Annex F2 were undertaken.

The additional surface water monitoring at DP4 for SS was conducted on 30 June 2022, 8 July 2022 and 15 July 2022. The SS exceedance at DP4 on 30 June 2022 and 8 July 2022 was found to be project-related upon further investigation.  The weekly surface water quality monitoring (SS) was conducted at DP4 until no exceedance of Limit Level.  Since the additional surface water monitoring results (SS) at DP4 on 15 July 2022 complied with the Limit Level as stipulated in the updated EM&A Manual, the weekly surface water monitoring (SS) at DP4 was terminated.

The results of the additional surface water monitoring are summarized in Table 2.23 below. Investigation reports of the exceedances are presented in Annex F6

Table 2.23      Details of Exceedances Recorded for Surface Water Quality Monitoring

Date

Monitoring Location

Parameter

Result

Limit Level

Remarks

25 May 2022

DP3

SS

31.8 mg/L

20 mg/L

Project-related

30 June 2022

DP4

SS

28.2 mg/L

20 mg/L

Weekly monitoring shall be continued

8 July 2022

DP4

SS

26.3 mg/L

20 mg/L

Weekly monitoring shall be continued

 

Based on the investigation conducted for the monitoring event with potential Action and Limit Levels exceedances with the Contractor, and the IEC, the exceedances were found deemed to Project-related activities. 

The Contractor was reminded to implement all relevant mitigation measures for the construction works and maintain good site practice.  The ET will keep track on the monitoring data and ensure Contractor’s compliance of the environmental requirements.

2.3.2                          Leachate Monitoring

Monitoring Requirements and Equipment

According to the updated EM&A Manual, continuous monitoring of leachate level and daily monitoring of effluent quality were carried out during the operation/ restoration phase.

Reduction of effluent monitoring frequency (dry season) (from daily to monthly) was approved by EPD on 22 March 2022. Monthly effluent quality monitoring (dry season) shall be conducted from 23 March 2022. The reduction of effluent monitoring frequency (wet season) (from daily to monthly) was approved by EPD on 2 August 2022.  Monthly effluent quality monitoring (wet season) shall be conducted from 3 August 2022. 

Temperature, pH and volume of the effluent discharged from the leachate treatment plant were measured in-situ whereas the parameters as listed in Table 2.22 were determined by ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066).

The Limit Levels of the leachate monitoring are provided in Table 2.24.

Table 2.24      Limit Levels for Leachate Levels and Effluent Quality

Parameters

Limit Level

Leachate Levels

 

Leachate levels above the basal liner

1 m above the primary liner of the leachate containment system

Effluent Quality

Temperature

> 43 °C

pH Value

6 – 10

Volume Discharged

>2,000 m³

Suspended Solids (SS)

> 800 mg/L

Phosphate

> 25 mg/L

Sulphate

> 800 mg/L

Total Inorganic Nitrogen (a)

> 100 mg/L

Biochemical Oxygen Demand (BOD)

> 800 mg/L

Chemical Oxygen Demand (COD)

> 2,000 mg/L

Oil & Grease

> 20 mg/L

Boron

> 7,000 µg/L

Iron

> 5 mg/L

Cadmium

> 1 µg/L

Chromium

> 300 µg/L

Copper

> 1,000 µg/L

Nickel

> 700 µg/L

Zinc

> 700 µg/L

Note:

(a)    Total Inorganic Nitrogen include Ammoniacal-nitrogen, Nitrite-nitrogen and Nitrate-nitrogen.

All in situ monitoring instruments were checked, calibrated and certified by a laboratory accredited under HOKLAS or other international accreditation scheme before use, and subsequently re-calibrated at 3 monthly intervals throughout all stages of the leachate quality monitoring programme.  Details of the equipment used are provided in Table 2.25

Table 2.25      Leachate Levels and Effluent Quality Monitoring Details

Location

Frequency

Parameter

Monitoring Dates

Equipment

Leachate levels above the basal liner

 

Continuous

Leachate Levels

1 Jan – 31 Dec 2022

Pairs of pressure transducers

Effluent discharged from LTP

Daily for the first 3 months upon full operation of the LTP at wet season (Apr to Sep) and dry season (Oct to Mar), respectively and reduce to monthly thereafter subject to the monitoring results of the first 3 months for each season and agreement with the EIAO Authority, IEC and IC. (a)

On-site Measurements:

·    Volume

·    pH

·    Temperature

Laboratory analysis:

·    Suspended Solids

·    COD

·    BOD5

·    TOC

·    Ammoniacal–nitrogen

·    Nitrate-nitrogen

·    Nitrite–nitrogen

·    Total Nitrogen

·    Sulphate

·    Phosphate

·    Oil & Grease

·    Alkalinity

·    Chloride

·    Calcium

·    Potassium

·    Magnesium

·    Iron

·    Zinc

·    Copper

·    Chromium

·    Nickel

·    Cadmium

·    Boron

 

1 Jan – 3 Aug 2022,

7 Sep 2022,

7 Oct 2022,

8 Nov 2022,

6 Dec 2022

Lutron WA-2017SD (S/N: T.016811)

 

TOA HM-30P (S/N: 790332)

 

LUTRON WA-2017SD

(S/N: T.016811)

 

HANNA H198103 (Eqt No.: HK1561)

 

COMARK PDT300 (S/N: 03948681155)

 

 

 

 

 

 

Note:

(a)    Reduction of monitoring frequency will be subject to the monitoring results to demonstrate environmentally acceptable performance.

Monitoring Schedule for the Reporting Month

The schedule for leachate monitoring during the reporting period is provided in Annex C.

Results and Observations

The leachate levels and effluent quality monitoring results are summarised in Table 2.26 and Table 2.27, respectively.  The detailed monitoring results are provided in Annex F3 and Annex F4, respectively.

Table 2.26      Summary of Leachate Levels in the Reporting Period

Monitoring Location

Average Leachate Head Levels (cm) (Range in Bracket)

Limit Level (cm)

Pump Station No. 1X (Cell 1X)

Meter No. X-1

68 (28 - 103)

> 178

Meter No. X-2

79 (33 – 117)

 

Average

74 (38 – 107)

 

Pump Station No. 2X (Cell 2X)

Meter No. X-3

80 (46 – 125)

> 180

Meter No. X-4

76 (39 – 104)

 

Average

78 (48 – 104)

 

Pump Station No. 3X (Cell 3X)

Meter No. X-5

75 (46 – 232)

> 175

Meter No. X-6

76 (48 – 237)

 

Average

76 (48 – 235)

 

Pump Station No. 4X (Cell 4X)

 

> 186

Meter No. X-7

82 (48 – 329)

Meter No. X-8

85 (50 – 331)

Average

84 (49 – 330)

 

Table 2.27      Summary of Effluent Quality Monitoring Results in the Reporting Period

Parameters

Monitoring Results

Limit Level

 

 

Average

Min

Max

 

 

Temperature

°C

30.3

20.4

36.9

> 43 °C

 

pH Value

pH unit

8.4

8.1

8.6

6 – 10

 

Volume Discharged

1153.5

616.0

1995.0

>2,000 m³

 

Suspended Solids (SS)

mg/L

31.5

23.6

51.2

> 800 mg/L

 

Phosphate

mg/L

6.4

2.5

12.7

> 25 mg/L

 

Sulphate

mg/L

201.8

97.0

385.0

> 800 mg/L

 

Total Inorganic Nitrogen (a)

mg/L

50.4

33.7

65.9

> 100 mg/L

BOD

mg/L

10.6

8.0

25.0

> 800 mg/L

COD

mg/L

928.5

484.0

1600.0

> 2,000 mg/L

Oil & Grease

mg/L

<5.0

<5.0

<5.0

> 20 mg/L

 

Boron

µg/L

4685.9

3400.0

5760.0

> 7,000 µg/L

 

Iron

mg/L

1.5

0.7

3.3

> 5 mg/L

 

Cadmium

µg/L

<1.0

<1.0

<1.0

> 1 µg/L

 

Chromium

µg/L

127.1

74.0

343.0

> 300 µg/L

 

Copper

µg/L

16.5

<10.0

29.0

> 1,000 µg/L

 

Nickel

µg/L

107.6

74.0

163.0

> 700 µg/L

 

Zinc

µg/L

87.4

50.0

234.0

> 700 µg/L

 

Limit Levels exceedances were recorded for leachate level monitoring and leachate (Chromium) during water quality monitoring in the reporting period and actions in accordance with the Event and Action Plan presented in Annex F2. Investigation of the Action and Limit Levels exceedances was conducted and the investigation reports are presented in Annex F6. Based on the investigation conducted for the monitoring event with potential Limit Levels exceedance with the Contractor and the IEC, the leachate level exceedances at Pump Station No. 4X from 12 August to 20 August 2022, from 30 September 2022 to 3 October 2022 and from 3 November 2022 to 4 November 2022, and at Pump Station No. 3X on 3 November 2022 were considered Project-related. The leachate (Chromium) exceedance on 6 December 2022 was considered Project related.

The Contractor was reminded to implement all relevant mitigation measures for the construction and operation works and maintain good site practice.  The ET will keep track on the monitoring data and ensure Contractor’s compliance of the environmental requirements..

2.3.3                          Groundwater Monitoring

Monitoring Requirements and Equipment

According to the updated EM&A Manual of the Project with incorporation of the proposed updates under the Amendment Summary approved by EPD on 15 June 2020, groundwater monitoring was carried out at 14 perimeter groundwater monitoring wells (including 3 up-gradient wells and 11 down-gradient wells) (i.e. MWX-1 to MWX-14) to monitor the groundwater quality and level of the perimeter groundwater monitoring wells at monthly interval.

The Limit Levels for groundwater quality is provided in Table 2.28 below.

Table 2.28      Limit Levels for Groundwater Quality

Location

Limit Levels

Ammoniacal-nitrogen (mg L-1)

COD (mg L-1)

MWX-1

5.00

30

MWX-2

5.00

30

MWX-3

5.00

30

MWX-4

7.63

36

MWX-5

5.00

30

MWX-6

5.00

46

MWX-7

6.55

36

MWX-8

15.85

50

MWX-9

7.30

71

MWX-10

5.00

30

MWX-11

5.00

30

MWX-12

5.00

30

MWX-13

5.00

30

MWX-14

5.00

30

A bladder pump with Teflon sampling tube and adjustable discharge rates was used for purging and taking of groundwater sample from the monitoring wells.  Filtered groundwater samples were collected by connecting a disposable in-line filter system to the tubing of the sampling pump, prior to storage and analysis by ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066). 

A portable dip meter with 5mm accuracy was used for measurement of groundwater level at each well.  The dip meter has an audio indicator of the water level and was checked before use.

The measurements of pH and electrical conductivity (EC) were undertaken in situIn situ monitoring instruments in compliance with the specifications listed under Section 4.3.2 of the updated EM&A Manual were used to undertake the groundwater quality monitoring for the Project. 

Details of the equipment used and the monitoring locations are summarised in Table 2.29 and illustrated in Figure 2.1, respectively.

Table 2.29      Groundwater Monitoring Details

Monitoring Location

Frequency

Parameter

Monitoring Dates

Equipment

All groundwater monitoring wells (MWX-1 to MWX-14)

Monthly

·   Water level

·   pH

·   EC

·   COD

·   BOD5

·   TOC

·   Ammoniacal–nitrogen

·   Nitrate-nitrogen

·   Nitrite–nitrogen

·   TKN

·   TN

·   Sulphate

·   Sulphide

·   Carbonate

·   Bicarbonate

·   Phosphate

·   Chloride

·   Sodium

·   Potassium

·   Calcium

·   Magnesium

·   Nickel

·   Manganese

·   Chromium

·   Cadmium

·   Copper

·   Lead

·   Iron

·   Zinc

·   Mercury

·   Boron

4, 11 Jan 2022,

15, 18 Feb 2022,

14, 15 Mar 2022,

11, 12 Apr 2022

10, 11, 18

May 2022,

6, 14 Jun 2022,

4, 5 Jul 2022, 17,

18 Aug 2022,

5, 6 Sept 2022,

10, 11 Oct 2022,

7, 8 Nov 2022,

12, 13 Dec 2022

YSI Professional DSS (S/N: 17B102764)

 

YSI Professional DSS (S/N: 15H103928)

Monitoring Schedule for the Reporting Month

The schedule for groundwater quality monitoring during the reporting period is provided in Annex C.

Results and Observations

The groundwater quality monitoring results and detailed monitoring results are summarised in Table 2.30 and provided in Annex F5, respectively.

Table 2.30      Summary of Groundwater Monitoring Results in the Reporting Period

Location

Ammoniacal-nitrogen (mg L-1)

COD (mg L-1)

Average Monitoring Results

Limit Levels

Average Monitoring Results

Limit Levels

MWX-1

0.48

5.00

10

30

MWX-2

0.77

5.00

9

30

MWX-3

1.27

5.00

16

30

MWX-4

4.10

7.63

27

36

MWX-5

1.79

5.00

24

30

MWX-6

3.54

5.00

42

46

MWX-7

5.69

6.55

22

36

MWX-8

9.68

15.85

35

50

MWX-9

2.09

7.30

30

71

MWX-10

0.02

5.00

11

30

MWX-11

0.07

5.00

6

30

MWX-12

0.02

5.00

5

30

MWX-13

0.04

5.00

6

30

MWX-14

0.05

5.00

4

30

Limit Levels exceedances were recorded for groundwater monitoring in the reporting period and actions in accordance with the Event and Action Plan presented in Annex F2 were undertaken. Investigation of the Limit Levels exceedances was conducted and the investigation report is presented in Annex F6.

Based on the investigation conducted for the monitoring event with potential Limit Levels exceedance with the Contractor and the IEC, the groundwater quality (COD) exceedances at MWX-4 and MWX-6 on 15 February 2022, at MWX-4 on 15 March 2022, at MWX-4, MWX5, MWX6 on 11 April 2022 and at MWX-7 on 18 August 2022 and 6 September 2022 were considered non Project-related. 

The Contractor was reminded to implement all relevant mitigation measures for the construction and operation works and maintain good site practice.  The ET will keep track on the monitoring data and ensure Contractor’s compliance of the environmental requirements.

2.4                               Landfill Gas Monitoring

2.4.1                          Monitoring Requirements

According to the updated EM&A Manual of the Project, landfill gas monitoring was carried out at the perimeter of the waste boundary (monitoring wells), area between the SENTX Site boundary and the waste boundary (surface emission), occupied on-site building, service voids, utilities pit and manholes in the vicinity of the SENTX (build-up of landfill gas) during the operation/restoration phase.

The Limit Levels for landfill gas monitoring is provided in Table 2.31 below.

Table 2.31      Limit Levels for Landfill Gas Constituents

Parameters

Monitoring Location

Limit Level (% (v/v))

Perimeter Landfill Gas Monitoring Wells (a)             

 

Methane & Carbon Dioxide

 

Methane

Carbon Dioxide

 

LFG1

1.0

2.2

 

LFG2

1.0

4.2

 

LFG3

1.0

6.3

 

LFG4

1.0

7.0

 

LFG5

1.0

3.4

 

LFG6

1.0

9.1

 

LFG7

1.0

1.5

 

LFG8

1.0

1.7

 

LFG9

2.5

1.7

 

LFG10

1.0

1.6

 

LFG11

3.0

2.0

 

LFG12

13.2

1.5

 

LFG13

22.5

2.7

 

LFG14

1.0

1.6

 

LFG15

18.2

2.0

 

LFG16

1.0

1.7

 

LFG17

10.5

2.1

 

LFG18

2.3

1.9

 

LFG19

6.3

3.1

 

LFG20

1.0

4.2

 

LFG21

1.0

4.3

 

LFG22

1.0

3.9

 

LFG23

1.0

10.3

 

LFG24

1.0

4.0

 

GP1

1.0

8.5

 

GP2 (shallow)

1.0

11.4

 

GP2 (deep)

1.0

10.4

 

GP3 (shallow)

1.0

3.9

 

GP3 (deep)

1.0

1.9

 

GP4 (shallow)

1.0

2.3

 

GP4 (deep)

1.0

5.6

 

GP5 (shallow)

1.0

9.5

 

GP5 (deep)

1.0

7.5

 

GP6

1.0

7.8

 

GP7

1.0

4.5

 

GP12

1.0

2.3

 

GP15

1.0

2.2

 

P7

1.0

2.5

 

P8

1.0

1.7

 

P9

1.0

2.7


 

Service Voids, Utilities Pits and Manholes

Methane (or flammable gas)

Service voids, utilities pits and manholes

1% by volume

Permanent Gas Monitoring System

Methane (or flammable gas)

Permanent Gas Monitoring System

1% by volume (20% LEL)

Area Between the SENTX Site Boundary and Waste Boundary (Surface Emission)

Flammable gas

Area between SENTX site boundary and waste boundary

30 ppm

Notes:

(a)    Limit Levels established based on the pre-operation phase baseline and additional landfill gas monitoring results in the Pre-operation Baseline Monitoring Report.

Gas analysers in compliance with the specifications listed under Section 5.4.1 of the updated EM&A Manual were used to monitor the gas parameters at the landfill gas monitoring wells, service voids, utilities pits and manholes.  The gas analyser was calibrated by a laboratory accredited under HOKLAS at yearly intervals and checked before use to ensure the validity and accuracy of the results.  A portable dip meter was used to monitor the water level in the monitoring wells.

Permanent gas monitoring systems with pre-set alarm levels for methane at 20% lower explosive limit (LEL, equivalent to 1% methane gas (v/v)) were installed and operated in all occupied on-site buildings at SENTX.  A central control panel is equipped to alert site personnel when the gas concentration at any detector reaches the alarm level.

Flammable gas detector in compliance with the specifications listed under Section 5.4.1 of the updated EM&A Manual was used to measure flammable gas concentration.  Flammable gas surface emission survey was conducted at a slow pace with the inlet tube of the meter probe a few centimeters above ground surface to detect flammable gas emitted from the ground surface. 

Bulk gas samples were collected into inert sample containers (i.e. Tedlar Bag) and transferred to ALS Technichem (HK) Pty Ltd. (HOKLAS Registration No. 066) laboratory within 24 hours of collection for direct analysis on a gas chromatography within 48 hours after collection.  

The equipment used in the landfill gas monitoring programme is summarised in Table 2.32.  The landfill gas monitoring locations for perimeter landfill gas monitoring wells and service voids, utilities and manholes along the Site boundary and within the SENTX site are illustrated in Figure 2.32.4 and Annex G1, respectively.




Table 2.32      Landfill Gas Monitoring Details

Monitoring Location

Frequency

Parameter

Monitoring Dates

Equipment

Perimeter landfill gas monitoring wells (LFG1 to LFG24, P7 to P9, GP1 to GP7, GP12 and GP15)

 

Monthly

Ÿ  Methane

Ÿ  Carbon dioxide

Ÿ  Oxygen

Ÿ  Atmospheric    pressure

18 Jan 2022,

9 Feb 2022,

8 Mar 2022,

7 Apr 2022,

17 May 2022,

12 Jun 2022,

12 Jul 2022,

15 Aug 2022,

16 Sep 2022,

3 Oct 2022,

1 Nov 2022,

6 Dec 2022

GA5000 (S/N: G507306)

Service voids, utilities and manholes along the Site boundary and within the SENTX Site (UU1 to UU28)

Monthly

Ÿ  Methane

Ÿ  Carbon dioxide

Ÿ  Oxygen

20 Jan 2022,

11 Feb 2022,

11 Mar 2022,

8 Apr 2022,

16 May 2022,

13 Jun 2022,

13 Jul 2022,

5 Aug 2022,

13 Sep 2022,

5 Oct 2022,

4 Nov 2022,

9 Dec 2022

GA5000 (S/N: G507306)

Permanent gas monitoring system in all occupied on-site buildings

Continuous

Ÿ  Methane (or flammable gas) by permanent gas monitoring system

1 Jan – 31 Dec 2022

Permanent gas monitoring system

Areas between the SENTX Site boundary and the waste boundary and location of vegetation stress

Quarterly

Ÿ  Flammable gas emitted from the ground surface

15 Feb 2022,

18 May 2022,

16 Aug 2022,

18 Nov 2022

GMI Leak Surveyor (S/N: 554846)

Bulk gas sampling at least 2 of the perimeters LFG monitoring wells

Quarterly

Ÿ  Methane

Ÿ  Carbon dioxide

Ÿ  Oxygen

Ÿ  Nitrogen

Ÿ  Carbon monoxide

Ÿ  Other flammable gas

16 Feb 2022,

17 May 2022,

15 Aug 2022,

1 Nov 2022

Gas sampling pump and Tedlar bags

Monitoring Schedule for the Reporting Month

The schedule for dust monitoring during the reporting period is provided in Annex C.

Results and Observations

The landfill gas monitoring results are summarised and provided in Tables 2.33 - 2.36 and Annex G2, respectively.

Table 2.33      Summary of Landfill Gas Monitoring Results at Perimeter LFG Monitoring Wells in the Reporting Period

Location

Methane (% (v/v))

Carbon Dioxide (% (v/v))

Monitoring Results

Limit Level (a)

Monitoring Results

Limit Level (a)

Average

Min

Max

Average

Min

Max

LFG1

0.0

0.0

0.0

1.0

0.4

0.0

1.5

3.2

LFG2

0.0

0.0

0.0

1.0

0.7

0.0

2.4

4.3

LFG3

0.0

0.0

0.1

1.0

0.4

0.0

1.8

6.3

LFG4

0.0

0.0

0.0

1.0

0.2

0.0

0.7

7.0

LFG5

0.0

0.0

0.0

1.0

0.2

0.0

0.3

3.4

LFG6

0.2

0.0

1.8

1.0

0.5

0.0

2.1

9.1

LFG7

0.0

0.0

0.0

1.0

0.0

0.0

0.1

1.5

LFG8

1.0

0.0

8.9

12.6

0.1

0.0

0.5

2.4

LFG9

0.2

0.0

1.5

2.5

0.1

0.0

0.3

1.7

LFG10

0.6

0.0

2.9

3.5

0.0

0.0

0.1

1.6

LFG11

0.1

0.0

0.8

3.0

0.1

0.0

0.5

2.0

LFG12

0.0

0.0

0.0

13.2

0.0

0.0

0.1

1.5

LFG13

5.4

0.0

24.1

22.5

0.1

0.0

0.9

2.7

LFG14

0.2

0.0

2.4

5.2

0.0

0.0

0.2

1.8

LFG15

0.8

0.0

4.1

18.2

0.1

0.0

0.3

2.0

LFG16

0.0

0.0

0.1

1.0

0.0

0.0

0.1

2.0

LFG17

1.4

0.0

15.9

17.8

0.1

0.0

0.5

2.4

LFG18

0.0

0.0

0.0

2.3

0.0

0.0

0.1

2.1

LFG19

0.0

0.0

0.0

6.3

0.0

0.0

0.2

3.1

LFG20

0.0

0.0

0.0

1.0

0.4

0.0

2.5

4.6

LFG21

0.0

0.0

0.0

1.0

1.0

0.0

3.0

4.8

LFG22

0.0

0.0

0.0

1.0

0.5

0.0

2.3

4.0

LFG23

0.0

0.0

0.0

1.0

2.3

0.4

4.7

10.3

LFG24

0.0

0.0

0.0

1.0

0.5

0.0

1.0

4.7

GP1

0.0

0.0

0.2

1.0

3.5

0.1

8.5

10.6

GP2 (shallow)

0.0

0.0

0.1

1.0

0.2

0.0

1.2

11.4

GP2 (deep)

0.1

0.0

0.3

1.0

1.4

0.0

8.0

10.4

GP3 (shallow)

0.0

0.0

0.1

1.0

0.8

0.1

3.3

6.9

GP3 (deep)

0.0

0.0

0.0

1.0

0.3

0.1

1.0

5.6

GP4 (shallow)

0.0

0.0

0.0

1.0

0.3

0.1

1.1

11.6

GP4 (deep)

0.0

0.0

0.1

1.0

0.2

0.1

0.4

7.7

GP5 (shallow)

0.0

0.0

0.0

1.0

3.8

0.1

8.4

10.8

GP5 (deep)

0.0

0.0

0.0

1.0

0.1

0.0

0.1

7.5

GP6

0.0

0.0

0.0

1.0

4.5

0.1

6.7

8.4

GP7

0.0

0.0

0.0

1.0

0.3

0.0

1.4

4.5

GP12

0.0

0.0

0.1

1.0

0.2

0.0

0.6

2.3

GP15

0.0

0.0

0.2

1.0

0.0

0.0

0.1

2.2

P7

0.0

0.0

0.1

1.0

0.0

0.0

0.1

2.5

P8

0.0

0.0

0.2

1.0

0.0

0.0

0.1

1.7

P9

0.0

0.0

0.2

1.0

0.1

0.0

0.3

2.7

Notes:

(a) Limit Levels established based on the pre-operation phase baseline and additional landfill gas monitoring results in the Pre-operation Baseline Monitoring Report.

 

Table 2.34      Summary of Landfill Gas Monitoring Results at Service Voids, Utilities Pits and Manholes in the Reporting Period

Location

Methane (% (v/v))

Monitoring Results

Limit Levels

Average

Min

Max

UU01

0.0

0.0

0.1

1.0

UU02

0.0

0.0

0.1

1.0

UU03

0.1

0.0

0.2

1.0

UU04

0.0

0.0

0.2

1.0

UU05

0.0

0.0

0.2

1.0

UU06

0.1

0.0

0.2

1.0

UU07

0.1

0.0

0.3

1.0

UU08

0.1

0.0

0.3

1.0

UU09

0.0

0.0

0.0

1.0

UU10

0.0

0.0

0.0

1.0

UU11

0.0

0.0

0.0

1.0

UU12

Voided due to latest site programme and on-going operation work

1.0

UU13

0.0

0.0

0.0

1.0

UU14

0.0

0.0

0.0

1.0

UU15

0.0

0.0

0.0

1.0

UU16

0.0

0.0

0.0

1.0

UU17

Voided due to latest site programme and on-going operation work

1.0

UU18

0.0

0.0

0.1

1.0

UU19

0.1

0.0

0.2

1.0

UU20

0.0

0.0

0.1

1.0

UU21

0.0

0.0

0.0

1.0

UU22

0.0

0.0

0.1

1.0

UU23

0.0

0.0

0.1

1.0

UU24

0.0

0.0

0.1

1.0

UU25

0.0

0.0

0.1

1.0

UU26

0.0

0.0

0.2

1.0

UU27

0.0

0.0

0.2

1.0

UU28

0.0

0.0

0.1

1.0

 

 

 

 

 

 

 

 

 

 

Table 2.35 Summary of Landfill Gas Bulk Gas Sampling Monitoring Results in the Reporting Period

 

Parameters

Limit Level (LFG14) (a)     

LFG14

Limit Level (LFG15) (a)     

LFG15

 

February 2022

 

 

 

 

 

Methane (% (v/v))

1.0

0.0

18.2

0.0

 

Carbon Dioxide (% (v/v))

1.6

0.119

2.0

0.110

 

Oxygen (% (v/v))

-

10.2

-

20.1

 

Nitrogen (% (v/v))

-

90.5

-

80.3

 

Carbon Monoxide (% (v/v))

-

<0.020

-

<0.020

 

Hydrogen (% (v/v))

-

<0.020

-

<0.020

 

Ethane (ppmv)

-

<1.0

-

<1.0

 

Propane (ppmv)

-

<1.0

-

<1.0

 

Butane (ppmv)

-

<1.0

-

<1.0

 

Parameters

Limit Level (LFG12) (a)      

LFG12

Limit Level (LFG24) (a)     

LFG24

 

May 2022

 

 

 

 

 

Methane (% (v/v))

13.2

0.415

1.0

<0.020

 

Carbon Dioxide (% (v/v))

1.5

0.038

4.7

1.03

 

Oxygen (% (v/v))

-

19.9

-

19.6

 

Nitrogen (% (v/v))

-

78.7

-

79.0

 

Carbon Monoxide (% (v/v))

-

<0.020

-

<0.020

 

Hydrogen (% (v/v))

-

<0.020

-

<0.020

 

Ethane (ppmv)

-

<1.0

-

<1.0

 

Propane (ppmv)

-

<1.0

-

<1.0

 

Butane (ppmv)

-

<1.0

-

<1.0

 

Parameters

Limit Level (LFG20) (a)     

LFG20

Limit Level (LFG23) (a)      

LFG23

 

August 2022

 

 

 

 

 

Methane (% (v/v))

1.0

<0.020

1.0

<0.020

 

Carbon Dioxide (% (v/v))

4.6

0.059

10.3

0.062

 

Oxygen (% (v/v))

-

20.6

-

20.7

 

Nitrogen (% (v/v))

-

77.5

-

77.3

 

Carbon Monoxide (% (v/v))

-

<0.020

-

<0.020

 

Hydrogen (% (v/v))

-

<0.020

-

<0.020

 

Ethane (ppmv)

-

<1.0

-

<1.0

 

Propane (ppmv)

-

<1.0

-

<1.0

 

Butane (ppmv)

-

<1.0

-

<1.0

 

Parameters

Limit Level (LFG1) (a)         

LFG1

Limit Level (LFG8) (a)       

LFG8

 

November 2022

 

 

 

 

 

Methane (% (v/v))

1.0

<0.0200

12.6

<0.020

 

Carbon Dioxide (% (v/v))

3.2

0.419

2.4

0.138

 

Oxygen (% (v/v))

-

15.6

-

17.2

 

Nitrogen (% (v/v))

-

80.6

-

79.2

 

Carbon Monoxide (% (v/v))

-

<0.020

-

<0.020

 

Hydrogen (% (v/v))

-

<0.020

-

<0.020

 

Ethane (ppmv)

-

<1.0

-

<1.0

 

Propane (ppmv)

-

<1.0

-

<1.0

 

Butane (ppmv)

-

<1.0

-

<1.0

Notes:

(a) Limit Levels established based on the pre-operation phase baseline and additional landfill gas monitoring results in the Pre-operation Baseline Monitoring Report.

 

Table 2.36      Summary of Flammable Gas Surface Emission Monitoring Results in the Reporting Period

GPS Coordinates

Latitude (N)

 

Longitude (E)

Monitoring Results (ppm)

Limit Level (ppm)

February 2023

 

 

30

22o16’36”

114o16’36”

3

22o16’24”

114o16’36”

6

May 2023

 

 

22o16’31” 

114o16’17” 

8

22o16’53” 

114o16’17” 

5

August 2023

 

 

22o16’33”

114o16’17”

3

22o16’16”

114o27’78”

6

22o16’15”

114o16’33”

12

22o16’14”

114o16’28”

8

22o16’23”

114o16’26”

8

22o16’30”

114o16’26”

21

22o16’37”

114o16’27”

15

22o16’37”

114o16’31”

12

November 2023

 

 

22o16’26”

114o16’35”

25

22o16’26”

114o16’34”

11

The alarm of the permanent gas monitoring systems with pre-set levels for methane at 20% lower explosive limit (LEL, equivalent to 1% methane gas (v/v)) was not triggered at all occupied on-site buildings at SENTX in the reporting period.

Limit Levels exceedances were recorded for perimeter landfill gas monitoring in the reporting period and actions in accordance with the Event and Action Plan presented in Annex G3 were undertaken.  Investigation of the Action and Limit Levels exceedances was conducted and the investigation report is presented in Annex G4Based on the investigation conducted for the monitoring event with potential Limit Levels exceedance with the Contractor and the IEC, the perimeter landfill gas exceedance at LFG6 and LFG13 on 17 May 2022 and 3 October 2022 were considered non Project-related. 

The Contractor was reminded to implement all relevant mitigation measures for the construction and operation works and maintain good site practice.  The ET will keep track on the monitoring data and ensure Contractor’s compliance of the environmental requirements.

2.5                               Landscape and Visual Monitoring

2.5.1                          Monitoring Requirements

According to the updated EM&A Manual of the Project, the monthly landscape and visual audit was conducted on 27 January 2022, 24 February 2022, 18 March 2022, 22 April 2022, 25 May 2022, 24 June 2022, 15 July 2022, 2 August 2022, 22 September 2022, 27 October 2022, 17 November 2022 and 22 December 2022 to monitor the implementation of the landscape and visual mitigation measures during operation/ restoration phase.

All relevant environmental mitigation measures listed in the approved EIA Report and the updated EM&A Manual and their implementation status are summarised in Annex B.

2.5.2                          Results and Observations

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

Regarding the landscape and visual audit, the Contractor was reminded to maintain the advance screen planting works regularly to ensure effective screening of views of project works from the High Junk Peak Trail.

2.6                               EM&A Site Inspection

Site inspections were carried out on a weekly basis with the Contractor, IEC and ER to monitor the implementation of proper environmental pollution control and mitigation measures for air quality, noise, water quality, landfill gas and waste management under the Project.  In the reporting period, 52 site inspections were carried out on the following dates:

·        6, 13, 20, 27 and 31 January 2022;

·        10, 17 and 24 February 2022;

·        3, 10, 17, 24 and 31 March 2022;

·        7, 14, 21 and 28 April 2022;

·        5, 12, 19 and 25 May 2022;

·        2, 9, 16, 23 and 30 June 2022;

·        7, 14, 21 and 28 July 2022;

·        4, 11, 18 and 26 August 2022;

·        1, 8, 15, 22 and 29 September 2022;

·        6, 13, 20 and 27 October 2022;

·        3, 10, 17 and 24 November 2022; and

·        1, 8, 15, 22 and 29 December 2022.

Key observations during the site inspections are summarized in Table 2.37.

Table 2.37      Key Observations Identified during the Site Inspections in this Reporting Period

Inspection Date

Environmental Observations and Recommendations

6 January 2022

·           The Contractor shall replace the faded NRMM label displayed on the generators near DP3 and maintenance building.

·           The Contractor shall provide drip trays for the chemicals stored near DG house and Chunwo container area.

·           The Contractor shall remove the stagnant water and general refuse accumulated at the channel near sump house 3.

·           The Contractor shall remove the general refuse accumulated near water services house regularly to minimise odour and pest issues.

13 January 2022

·           The Contractor shall remove the stagnant water and general refuse accumulated at the channel near sump house 3.

·           The Contractor shall clean up the oil spill at the breaker near buttress wall, handle the clean-up materials as chemical waste and maintain the break to avoid oil spillage, if necessary.

·           The Contractor shall dispose of the emptied chemical containers at Cell4X and near pump house 3 as chemical waste in the chemical waste cabinet.

·           The Contractor shall remove the general refuse accumulated near DP3 and dispose of the waste regularly to minimize odour and pest issues.

20 January 2022

·           The Contractor shall clean up the oil spillage at the generator near GVL building and handle the clean-up materials as chemical waste.

·           The Contractor shall provide drip trays for the chemicals stored near DP3 and Chunwo container area.

·           The Contractor shall segregate the construction waste and materials near sediment trap and dispose of the waste regularly.

·           The Contractor shall maintain site tidiness and remove the general refuse accumulated at the channel near sump house 3, RC15, u channel near Chunwo container area and DP6 and dispose of the waste regularly to minimise odour and pest issues.

27 January 2022

·           The Contractor shall remove the stagnant water accumulated at the channel near sump house 3 regularly and spray larvicides for mosquito control, if necessary.

·           The Contractor shall maintain site tidiness and remove the general refuse accumulated near town gas plant and dispose of the emptied chemical containers as chemical waste.

31 January 2022

·           The Contractor shall clean up the oil spillage near sediment trap and DP6 channel and handle the clean-up materials as chemical waste.

·           The Contractor shall provide drip trays for the chemicals stored near sediment trap.

·           The Contractor shall dispose of the emptied chemical containers near sediment trap as chemical waste in accordance with the COP.

·           The Contractor shall remove the general refuse accumulated near RC15 and at the channel near Chun Wo container area and dispose of the waste regularly.

10 February 2022

·           The Contractor shall provide a NRMM label on the crane near sump house 4.

·           The Contractor shall remove the general refuse accumulated at the channel near sump house 3 and dispose of the waste regularly to minimise odour and pest issues.

17 February 2022

·           The Contractor shall provide drip tray for the chemical stored near X10a.

·           The Contractor shall remove the general refuse accumulated near X10a, Cell 3X perimeter bund and at the channel near sump house 3 and VWF, and dispose of the waste regularly.

24 February 2022

·           The Contractor shall cover the water tank near sediment trap with lid to minimise pest issues.

·           The Contractor shall remove the stagnant water accumulated at the channel near sump house 3 and at Cell 4X regularly and spray larvicides for mosquito control, if necessary.

·           The Contractor shall remove the stagnant water accumulated in the drip trays at Wetsep near sediment trap.

3 March 2022

·           The Contractor shall remove the general refuse accumulated at the channel near sump house 3 and along Western site boundary and dispose of the waste regularly.

·           The Contractor shall remove the stagnant water accumulated in the drip tray for generator at Cell 4X.

10 March 2022

·           The Contractor shall display a NRMM label on the excavator near RC15.

·           The Contractor shall remove the general refuse accumulated at the channel near sump house 2 and 3 and dispose of the waste regularly.

·           The Contractor shall clean up the oil spillage near sump house 4 and handle the clean-up materials as chemical waste.

·           The Contractor shall provide drip tray for the chemical stored at Cell 4X.

17 March 2022

·           The Contractor shall remove the stagnant water accumulated at the channel near pump house 3 regularly, and spray larvicides for mosquito control, if necessary.

·           The Contractor shall dispose of the waste and remove the stagnant water accumulated at the refuse skip near DP6 regularly to minimise odour and pest issues.

24 March 2022

·           The Contractor shall display a NRMM label on the excavator near EPD building.

·           The Contractor shall clean up the oil spillage at the excavator near pump house 3 and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the general refuse and stagnant water accumulated near Towngas plant and DP6 and dispose of the waste regularly to minimise odour and pest issues.

31 March 2022

·           The Contractor shall remove the stagnant water accumulated at the channel near sump house 3 regularly and spray larvicides for mosquito control, if necessary.

·           The Contractor shall remove the general refuse and stagnant water accumulated at the refuse skip near DP6 and Towngas plant and dispose of the waste regularly to minimise odour and pest issues.

7 April 2022

·           The Contractor shall remove the general refuse accumulated near DP3 and at the channel near sump house 3 and dispose of the waste regularly to minimise odour and pest issues.

·           The Contractor shall remove the stagnant water accumulated in the drip tray for generator at Cell 4X.

14 April 2022

·           The Contractor shall clean up the oil spillage near sump house 3 and handle the clean-up materials as chemical waste.

·           The Contractor shall provide drip tray for the chemical stored near sump house 4.

·           The Contractor shall maintain the drainage system near VWF and remove the stagnant water accumulated at DP6 channel and the sediment tank regularly, and spray larvicides for mosquito control, if necessary.

21 April 2022

·           The Contractor shall cover the stockpile of dusty materials near sediment trap to minimise dust impact.

·           The Contractor shall replace the NRMM labels displayed on the excavator near Cell 4X and roller near sump house 3 in accordance with the COP.

·           The Contractor shall remove the deposited silt and grit and refuse accumulated at DP3 sediment pit, channel near sump house 3 and DP6 regularly, to ensure they are functioning properly at all times.

·           The Contractor shall clean up the oil spillage at the excavator near guardhouse, near sediment trap and maintenance workshop and handle the clean-up materials as chemical waste.

28 April 2022

·           The Contractor shall remove the general refuse accumulated near Town gas plant and Sump house 3.

·           The Contractor shall remove the concrete residue accumulated near EPD building and designate an area for concrete truck washing.

·           The Contractor shall provide drip tray for the chemical stored near EPD building.

·           The Contractor shall clean up the oil spillage on the road between biogas plant and LTP and handle the clean-up as chemical waste.

5 May 2022

·           The Contractor shall replace the faded NRMM label displayed on the generator near sediment trap.

·           The Contractor shall provide drip trays for the chemicals stored near X10a channel and sump house 4.

·           The Contractor shall remove the stagnant water accumulated at the channel near sump house 3.

·           The Contractor shall remove the general refuse accumulated at channel X10a, near sediment trap and guard house and dispose of the waste regularly.

12 May 2022

·           The Contractor shall plug the drip tray for the generator near Cell4X to avoid leakage.

·           The Contractor shall review the treatment capacity of the Wetsep near DP4 and DP6 to ensure all surface water is treated before discharge.

·           The Contractor shall enhance surface water management around the site and remove the stagnant water accumulated at the channel near sump house 3.

·           The Contractor shall remove the general refuse accumulated at channel X10a and dispose of the waste regularly.

19 May 2022

·           The Contractor shall replace the NRMM label displayed on the electric generator near sump house 3 in accordance with COP.

·           The Contractor shall operate the Wetsep near DP4 and review its’ treatment capacity to prevent non-compliance with the standard in WPCO licence and EM&A requirement.

·           The Contractor shall clean up the oil spillage on the road between biogas plant and LTP and handle the clean-up as chemical waste.

·           The Contractor shall remove the general refuse accumulated near sump house 3, DP4T and RC15 and dispose of the waste regularly to minimize odour and pest issue.

·           The Contractor shall remove the stagnant water accumulated in the drip tray for the electric generator near LTP.

25 May 2022

·           The Contractor shall replace the NRMM label displayed on telescopic handler near buttress wall in accordance with COP.

·           The Contractor shall provide drip trays for the chemicals stored near cell 4X, at channel x10c, bar bending area and Paul Y container area.  The Contractor shall also remove the stagnant water and chemical accumulated in the drip trays near Paul Y container area and treat the clean-up materials as chemical waste.

·           The Contractor shall clean up the oil spillage at channel x10c, Paul Y container area, near town gas plant and around LTP and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the stagnant water accumulated near DP6 and spray larvicides for mosquito control, if necessary.

·           The Contractor shall review Wetsep treatment efficiency to prevent non-compliance with the WPCO standard and EM&A requirement.

·           The Contractor shall remove the general refuse accumulated near town gas plant, bar bending area, Paul Y container area and RC15 and remove the gravel along the road near MSE wall and dispose of the waste regularly to maintain site cleanliness and tidiness.

·           The Contractor shall remove the concrete residue accumulated near X10C and designate an area for concrete truck washing.

·           The contractor shall remove the deposited silt and refuse accumulated at the surface water channels near Paul Y container area and town gas plant to ensure they are functioning properly at all times.

·           The Contractor shall ensure that the wheel washing facilities are functioning properly at all times and all trucks shall pass the wheel washing facilities before leaving the site to keep the public road clear of muddy materials.

2 June 2022

·           The Contractor shall display a NRMM label on the excavator near Cell 4X.

·           The Contractor shall clean up the oil spillage near the drip tray at Paul Y container area and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the stagnant water accumulated at the lifting eyes of the concrete blocks near Paul Y container area, and spray larvicides for mosquito control, if necessary.

·           The Contractor shall maintain site tidiness and remove the general refuse accumulated near Paul Y container area and at the temporary drain near GVL container area.

9 June 2022

·           The Contractor shall provide surface water management around the site (especially at DP3 upstream) and review the treatment capacity of the Wetsep near DP4 and DP6 to ensure all surface water is treated before discharge.

·           The Contractor shall clean up the oil spillage near buttress wall and Paul Y container area and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the stagnant water accumulated at the drip tray near Paul Y container area.

·           The Contractor shall remove the concrete residue near Paul Y container area and designate an area for concrete truck washing.

·           The Contractor shall remove the general refuse and vegetation at the temporary drain near Paul Y container area and site entrance.

16 June 2022

·           The Contractor shall replace the faded NRMM label displayed on the excavator near sump house 4 in accordance with the COP.

·           The Contractor shall provide surface water management at DP3 upstream (e.g. cover the exposed area and surface water diversion) to ensure that all surface water is treated before discharge.

·           The Contractor shall clean up the oil spillage near Paul Y container area and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the stagnant water accumulated at the drip tray near Paul Y container area.

·           The Contractor shall remove the general refuse and stagnant water accumulated at the channel near sump house 3 and dispose of the waste regularly.

23 June 2022

·           The Contractor shall cover the stockpile of dusty materials near DP3 to minimise dust impact.

·           The Contractor shall remove the deposited silt and grit accumulated at the sediment pits at DP3 and DP6 regularly to ensure they are functioning properly at all times.

·           The Contractor shall cover the exposed soil area at DP3 upstream to minimise muddy surface runoff to DP3 channel.

·           The Contractor shall remove the stagnant water accumulated at the drip tray near Paul Y container area and treat the contaminated water as chemical waste.

30 June 2022

·           The Contractor shall remove/ cover the stockpile of dusty materials near buttress wall to minimise dust impact.

·           The Contractor shall seal the baffle plates at DP3 channel and outlet and maintain the silt fencing along DP3 channel to minimise SS runoff to the channel.

·           The Contractor shall clean up the oil spillage near Towngas plant and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the stagnant water accumulated at the drip tray near Paul Y container area.

·           The Contractor shall maintain site tidiness and remove the general refuse accumulated around Paul Y container area.

7 July 2022

·           The Contractor shall display NRMM labels on the excavator near X10c channel and generator near DP6 and replace the faded NRMM label on the excavator near DP3.

·           The Contractor shall remove the general refuse accumulated at X10a channel regularly to ensure it is functioning properly at all times.

·           The Contractor shall remove the stagnant water accumulated at the drip tray near LTP.

·           The Contractor shall provide surface water management at DP3 upstream to minimise SS runoff to the channel.

14 July 2022

·           The Contractor shall display NRMM labels on the excavator at DP3 and roller near buttress wall.

·           The Contractor shall remove/ cover the stockpile of dusty materials near DP3 to minimise dust impact.

·           The Contractor shall provide surface water management at DP3 upstream to minimise SS runoff to the channel.

21 July 2022

·           The Contractor shall remove the deposited silt and grit and stagnant water accumulated at DP3 sediment pit regularly to ensure it is functioning properly at all times.

·           The Contractor shall remove the stagnant water accumulated in the manholes near channel X10C and spray larvicides for mosquito control, if necessary.

·           The Contractor shall provide surface water management at DP3 upstream and cover the exposed slope to minimise SS runoff to the channel.

·           The Contractor shall dispose of the empties chemical containers near DP3 as chemical waste in accordance with the COP.

28 July 2022

·           The Contractor shall remove the deposited silt and grit and stagnant water accumulated at DP3 sediment pit regularly to ensure it is functioning properly at all times.

·           The Contractor shall remove the general refuse and stagnant water accumulated at the channel near sump house 3 to minimize odour and pest issues and spray larvicides for mosquito control, if necessary.

·           The Contractor shall provide surface water management at DP3 upstream to minimise SS runoff to the channel.

·           The Contractor shall remove the algae and scum in the Wetsep near DP4 to ensure it is functioning properly at all times.

4 August 2022

·           The Contractor shall remove the general refuse accumulated near DP3 and dispose of the waste regularly.

·           The Contractor shall enhance the surface water management at DP3 upstream to minimise SS runoff to the channel.

·           The Contractor shall install pumps at DP3 to divert the surface water discharged from SENTX construction works to ensure all surface water is treated before discharge.

11 August 2022

·           The Contractor shall clear the dusty materials with road sweepers at the site entrance regularly to minimise dust impact.

·           The Contractor shall replace the faded NRMM label displayed on the excavator near western site boundary planting area.

·           The Contractor shall review the treatment capacity and efficiency of the Wetseps near DP4 to ensure all surface water is treated properly before discharge.

·           The Contractor shall remove the stagnant water accumulated in the drip trays of the Wetseps near DP4.

·           The Contractor shall remove the stagnant water and general refuse accumulated near sump house 3 and at X10a channel regularly.

18 August 2022

·           The Contractor shall remove the stagnant water accumulated in X10a channel regularly, and spray larvicides for mosquito control, if necessary.

·           The Contractor shall remove the general refuse accumulated at DP3 channel and X10a channel regularly to ensure they are functioning properly at all times.

26 August 2022

·           The Contractor shall provide drip trays for the chemicals stored near LTP.

·           The Contractor shall remove the general refuse and deposited silt accumulated at DP3 channel, X10c channel and surface water channels near town gas plant and LTP regularly to ensure they are functioning properly at all times.

·           The Contractor shall remove the general refuse accumulated near town gas plant, DP4 and LTP and dispose of the waste regularly.

·           The Contractor shall maintain the Wetsep near DP4 to ensure it is functioning properly at all times.

·           The Contractor shall sweep the road near vehicle exit regularly to ensure it is clear of dusty materials.

·           The Contractor shall improve the sewage drainage system to ensure that no untreated sewage is discharged to the surrounding water body.

1 September 2022

·           The Contractor shall clean up the oil spillage near DP6 container area and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the deposited silt and grit accumulated at DP3 sediment pit regularly.

·           The contractor shall remove the general refuse accumulated at X10a channel regularly to ensure it is functioning properly at all times.

8 September 2022

·           The Contractor shall clean up the oil spillage in sediment trap and treat the clean-up materials as chemical waste.

·           The Contractor shall remove the deposited silt and grit accumulated at DP3 sediment pit regularly.

·           The contractor shall remove the stagnant water accumulated at the channel leading to DP6.

·           The Contractor shall remove the general refuse around Paul Y area to maintain site cleanliness and tidiness.

·           The Contractor shall cover the stockpiles of dusty materials near maintenance building with impervious sheeting or remove them to minimize dust impact.

15 September 2022

·           The Contractor shall remove the general refuse accumulated near DP3 and dispose of the waste regularly to maintain site cleanliness.

·           The Contractor shall remove the deposited silt and grit and general refuse accumulated at DP3 sediment pit, outlet of sediment trap and DP6 regularly.

22 September 2022

·           The Contractor shall remove the general refuse accumulated at DP3 sediment pits regularly.

·           The Contractor shall enhance maintenance of the Wetsep at DP4 to ensure it is functioning properly at all times.

·           The Contractor shall clean up the oil spillage near LTP and handle the clean-up materials as chemical waste.

29 September 2022

·           The Contractor shall remove the general refuse accumulated at DP3 sediment pits regularly.

6 October 2022

·           The Contractor shall remove the general refuse accumulated at the surface channel near Paul Y area to ensure it is functioning properly at all times.

·           The Contractor shall remove the deposited silt accumulated at the surface channel near sump house 3 to ensure it is functioning properly at all times.

10 October 2022

·           The Contractor shall remove the general refuse accumulated near Paul Y area to maintain site cleanliness.

20 October 2022

·           The Contractor shall cover the stockpile of dusty materials by impervious sheeting near LTP to minimize dust impact issue.

·           The Contractor shall cover the exposed soil area near buttress wall area to reduce the contamination of runoff and erosion.

·           The Contractor shall refill flocculent agent in Wetsep at DP4 to ensure it is functioning properly at all times.

·           The Contractor shall remove the oil spillage near town gas plant and handle the clean-up materials as chemical waste.

·           The Contractor shall remove the general refuse accumulated at the channel leading to DP3, DP3 sediment pit, x10C channel and near Paul Y area to maintain site cleanliness.

27 October 2022

·           The Contractor shall remove the general refuse accumulated at the x10C channel to ensure it is functioning properly at all times.

3 November 2022

·           The Contractor shall remove the stagnant water and general refuse accumulated at DP3 sedimentation pit and X10a channel near sump house 2 to ensure they are functioning properly at all times.

·           The Contractor shall divert the SENTX surface water runoff affecting DP3 catchment area to the drop inlet X9 for discharge via sediment trap and DP4 in accordance with the Proposal on the Extension of Temporary Suspension of Surface Water Quality Monitoring at DP3.

·           The Contractor shall review the operation and treatment capacity of the Wetseps near DP4 and DP6 to ensure all surface water is treated before discharge.

·           The Contractor shall remove the general refuse accumulated at Paul Y area regularly to minimise odour and pest issues.

10 November 2022

·           The Contractor shall remove the general refuse, deposited silt and grit accumulated at X9 drop inlet and general refuse at X10a channel near sump house no. 2 to ensure they are functioning properly at all times.

·           The Contractor shall divert the SENTX surface water runoff affecting DP3 catchment area to the drop inlet X9 for discharge via sediment trap and DP4 in accordance with the Proposal on the Extension of Temporary Suspension of Surface Water Quality Monitoring at DP3.

·           The Contractor shall remove the stagnant water accumulated in the drip tray at Wetseps near DP4 and handle the clean-up materials as chemical waste.

17 November 2022

·           The Contractor shall remove the deposited silt and grit accumulated at X10a channel regularly to ensure it is functioning properly at all times.

24 November 2022

·           The Contractor shall remove the deposited silt and grit accumulated at X10a channel and stagnant water accumulated at DP3 sedimentation pit to ensure they are functioning properly at all times.

·           The Contractor shall divert the SENTX surface water runoff affecting DP3 catchment area to the drop inlet X9 for discharge via sediment trap and DP4 in accordance with the Proposal on the Extension of Temporary Suspension of Surface Water Quality Monitoring at DP3.

1 December 2022

·           The Contractor shall cover the stockpile of dusty materials by impervious sheeting in the Paul Y. area to minimize dust impact.

·           The Contractor shall remove the deposited silt and grit accumulated at X10a channel and general refuse at X10 channel near DP3 regularly to ensure they are functioning properly at all times.

·           The Contractor shall remove the silt and grit accumulated alongside X10 channel regularly to prevent surface run-off.

·           The Contractor shall remove the general refuse accumulated at area X2 along the access road to site entrance to minimize odour and pest issues.

8 December 2022

·           The Contractor shall remove the general refuse accumulated at X10 channel near DP3 and the deposited silt and grit accumulated at X10a channel to ensure they are functioning properly at all times.

15 December 2022

·           The Contractor shall remove the deposited silt and grit accumulated at X10a channel regularly to ensure it is functioning properly at all times.

22 December 2022

·           The Contractor shall enhance watering at the main haul road along the tie-in area to minimise dust impact.

·           The Contractor shall remove the general refuse, deposited silt and grit accumulated at X10a channel regularly to ensure it is functioning properly at all times.

29 December 2022

·           The Contractor shall remove the deposited silt and grit accumulated at X10a channel and the general refuse accumulated at X10 channel near DP3, X9 drop inlet and the channel downstream of the sediment trap to ensure they are functioning properly at all times.

The Contractor has rectified all of the observations identified during environmental site inspections in the reporting period.  Key environmental deficiencies identified and the corresponding rectification actions are presented in Table 2.38.

Table 2.38      Summary of Environmental Deficiencies Identified and Corresponding Additional Control Measures

Deficiencies

Rectifications Implemented

Proposed Additional Control Measures

Surface Water

Intercepting channels & drainage system

Ÿ  Reviewed drainage plan.

Ÿ Provision of additional drainage channels.

Ÿ Expedite the construction of permanent sediment trap and discharge culverts.

 

DP channels (design & regular silt removal)

Ÿ  Carried out regular maintenance and cleaning of channels.

Ÿ  DP4 channel: Area near the channel was paved with concrete and a bund was built.

Ÿ  DP6 channel: Gravel piles on the channel were covered with concrete which serve as blocks for running water and to divide the channel into several sections.  A pump was placed in the water zone in the upstream section to pump water to the Wetsep for treatment prior to the discharge to the last section before the weir plate.  

Ÿ  DP6: Pipes through the gravel piles between different channel sections were covered with geotextiles to block debris and silt.

 

N.A.

Stockpiles & exposed soil

Ÿ  Installed silt fencing near surface water channel along DP6 channel.

Ÿ  Improve soil covering.

Ÿ  Compaction and cover for stockpiles and soil slopes.

 

Wetsep (treatment capacity & number)

Ÿ  Reviewed Wetsep capacity.

Ÿ  Chemicals dosage of the Wetsep was increased to enhance the efficiency.

Ÿ  Install additional Wetsep.

Backflow / ponding during heavy rainfall

Ÿ  Raised with EPD (LDG) and CEDD.

N.A.

2.7                               Waste Management Status

The Contractor has registered as a chemical waste producer under the Contract.  Sufficient numbers of receptacles were available for general refuse collection and sorting.

As informed by the Contractor, waste generated during this reporting period include mainly non-inert C&D materials, yard waste and chemical wastes. Reference has been made to the waste flow table prepared by the Contractor.  The quantities of different types of wastes and imported fill materials are summarised in Table 2.39.

Table 2.39      Quantities of Different Waste Disposed and Imported Fill Materials

Month/ 

Year 

Inert C&D Materials (a) (in ‘000m3) 

Imported Fill 
(in ‘000kg) (b) 

Inert Construction Waste Re-used  
(in ‘000m3) 

Non-inert Construction Waste (c)  
(in ‘000m3) 

Recyclable Materials (d) 

(in ‘000kg) 

Yard Waste

(in ‘000kg) 

 

Chemical Wastes  
(in ‘000kg) 

Rock 

Soil 

Y Park 

SENT 

Jan 22

0.273

0

0

0

0.035

0

0

0

0.800

Feb 22

1.284

0

0

0

0.016

0

0

0

0.460

Mar 22

0.039

0

0

0

0.010

0

0

0

0.800

Apr 22

0

0

0

0

0.013

0

0

0

0.800

May 22

0

0

0

0

0.002

0

0

0

0.800

Jun 22

0

0

0

0

0

0

0

0

0.800

Jul 22

0.012

28.44

0.800 

Aug 22

0

0

0

0

0

0

0

0

0.800 

Sep 22

0

0

0

0

0

0

1.70

38.73

0.800 

Oct 22

0

0

0

0

0.001

0

6.930

82.000

0.800

Nov 22

0

0

0

0

0

0

35.90

252.39

0.800

Dec 22

0

0

0

0

0.0747

0

0

0

0.800

Notes: 

(a)    Inert construction wastes include hard rock and large broken concrete, and materials disposed as public fill.  Density assumption: 1.6 (kg/L) for public fill. 

(b)    Imported fill refers to materials generated from other project for on-site reuse. 

(c)    Non-inert construction wastes include general refuse disposed at landfill. Density assumption: 0.9 (kg/L) for general refuse.  

(d)    Recyclable materials include metals, paper, cardboard, plastics and others. 

2.8                               Implementation Status of Environmental Mitigation Measures

A summary of the Environmental Mitigation Implementation Schedule is presented in Annex B.  The necessary mitigation measures were implemented properly for the Project.

2.9                               Summary of Exceedances of the Environmental Quality Performance Limit

The operation/ restoration phase noise monitoring results complied with the Action and Limit Levels in the reporting period

Two exceedances of the Action and Limit Levels for dust (TSP), two exceedances of the Limit Level for landfill gas flare stack emission (SO2), one exceedance of Limit Level for landfill gas flare stack emission (Benzene), three exceedance of the Limit Level for surface water (SS), sixteen exceedances of the Limit Level for Leachate Level, one exceedance of Limit Level for leachate quality (Chromium), eight exceedances of the Limit Level for groundwater (COD) and two exceedances of the Limit Level for perimeter landfill gas monitoring (methane) were recorded in the reporting period.

The TSP exceedance at AM2 on 29 July 2022 was considered Project-related while the exceedance at AM4 on 29 July 2022 was considered non Project-related upon further investigation. The landfill gas flare stack emission (SO2) exceedances on 14 October 2022 and 17 November 2022 and landfill gas flare stack emission (Benzene) exceedance on 13 December 2022 were considered Project-related upon further investigation.

The SS exceedances at DP4 on 25 May 2022, 30 June 2022 and 8 July 2022 were found deemed to Project-related activities and weekly surface water quality (SS) monitoring has been commenced since June 2022.  The additional surface water monitoring results (SS) at DP4 on 15 July 2022 complied with the Limit Level as stipulated in the updated EM&A Manual and the weekly surface water monitoring (SS) at DP4 was terminated.

The groundwater (COD) exceedances at MWX-4 and MWX-6 on 15 February 2022, at MWX-4 on 15 March 2022, at MWX-4, MWX5 and MWX6 on 11 April 2022 and at MWX-7 on 18 August 2022 and 6 September 2022 were considered non Project-related upon further investigation.

The leachate level exceedances at Pump Station No. 4X from 12 August to 20 August 2022, from 30 September 2022 to 3 October 2022 and from 3 November 2022 to 4 November 2022, and at Pump Station No. 3X on 3 November 2022 were considered Project-related upon further investigation. 

The leachate quality (Chromium) exceedance on 6 December 2022 was considered Project-related upon further investigation.

The landfill gas (methane) exceedances at LFG6 on 17 May 2022 and at LFG13 on 3 October 2022 were considered non Project-related upon further investigation.

Cumulative statistics on exceedances is provided in Annex H.

2.10                            Summary of Complaints, Notification of Summons and Successful Prosecutions

There were no complaints, notification of summons or prosecution recorded in the reporting period.

Statistics on complaints, notifications of summons and successful prosecutions are summarised in Annex H.

3                                    Conclusion and Recommendation

This Annual EM&A Report presents the findings of the EM&A activities undertaken during the period from 1 January to 31 December 2022 in accordance with the updated EM&A Manual and the requirements of the Environmental Permit (EP-308/2008/B).

Air quality quality (24-hour TSP, odour, thermal oxidiser, landfill gas flare and landfill gas generator stack emission, ambient VOCs, ammonia and H2S), noise, water quality (surface water, leachate and groundwater) and landfill gas monitoring were carried out in the reporting period.  Results for noise monitoring complied with the Action and Limit Levels in the reporting period.

Two exceedances of the Action and Limit Levels for dust (TSP), two exceedances of the Limit Level for landfill gas flare stack emission (SO2), one exceedance of Limit Level for landfill gas flare stack emission (Benzene), three exceedance of the Limit Level for surface water (SS), sixteen exceedances of the Limit Level for Leachate Level, one exceedance of Limit Level for leachate quality (Chromium), eight exceedances of the Limit Level for groundwater (COD) and two exceedances of the Limit Level for perimeter landfill gas monitoring (methane) were recorded in the reporting period.

Fifty-two environmental site inspections were carried out during the reporting period.  Environmental deficiencies were identified during the site inspection and the Contractor has proposed additional control measures to rectify the deficiencies.

There were no complaints, notification of summons or prosecution recorded in the reporting period.

It is noted that most environmental pollution control and mitigation measures were properly implemented and the construction and operation activities of the Project did not introduce any adverse impact to the sensitive receivers in the reporting period.  Yet, some environmental deficiencies were identified during the reporting period and additional control measures have been proposed by the Contractor to rectify the corresponding deficiencies.  The monitoring programme has been reviewed and was considered as adequate to cater for the nature of works in progress.  Change to the monitoring programme was thus not recommended at this stage.  The monitoring programme will be evaluated as appropriate in the next reporting period.  The ET will keep track on the construction and operation works to confirm compliance of environmental requirements and the proper implementation of all necessary mitigation measures.

 

 



([1])          ERM (2018).  South East New Territories (SENT) Landfill Extension: Environmental Monitoring & Audit Manual

([2])          ERM (2007).  South East New Territories (SENT) Landfill Extension – Feasibility Study: Environmental Impact Assessment Report