Amendment History

 

Date:
Rev.
Description

05/2016

A

The EM&A Manual was updated based on the findings in the Environmental Review Report (November 2015) submitted to EPD to support the application for Variation for and Environmental Permit (VEP-487/2015) and matched with the current Environmental Permit (FEP-01/395/2010/C)

i.         Update programme in Table 1.1

ii.       Add ammonia stripping plant in section 2.3, 2.7 & 2.10

iii.      Add ammonia stripping plant in Table 2.1

iv.      Insert Table 2.5 Emission Limit for ASP

v.       New layout plan

This update also based on the comments from ET leader and IEC.

01/2017

 

02/2017

 

07/2017

B

 

C

 

D

The “Ammonia”was been inserted in Table 2.1

 

Add ammonia stripping plant to all parameters in Table 2.1

 

Table 2.2 was updated

 

 

 

 


 

ENVIRONMENTAL MONITORING AND AUDIT MANUAL

 

 

Contents

 

 

 

1        INTRODUCTION                                                                                                          

 

Purpose of Manual 

Project Description 

Project Organization 

Structure of this Manual

 

2        AIR QUALITY                                                                                                             

 

Introduction

Monitoring during Construction Phase

Monitoring during Commissioning Stage and Operation Phase

 

3        HAZARD TO LIFE                                                                                                       

 

Introduction 

Mitigation Measures

 

4        WATER QUALITY                                                                                                       

 

Introduction 

Construction Site Audits

Site Inspection

Compliance Audits

Mitigation Measures

 

5        WASTE MANAGEMENT                                                                                               

 

Introduction

Waste Management and Control During Construction Phase

Waste Management and Control During Operation Phase 

Approaches to Prevent Land Contamination

 

6        LANDSCAPE AND VISUAL                                                                                          

 

Introduction

Baseline Review

Mitigation Measures

Design Phase Audit

Construction and Operational Phase Audits

 

7        NOISE                                                                                                                        

 

Introduction

Good Site Practices

 

8        ENVIRONMENTAL AUDITING                                                                         

 

Site Inspection

Compliance with Legal and Contractual Requirements 

Environmental Complaints

 

9        REPORTING                                                                                                               

 

General

Baseline Monitoring Report

Monthly EM&A Report

Quarterly EM&A Summary Reports

Final EM&A Review Report

Data Keeping

Interim Notifications of Environmental Quality Limit Exceedances

 

 

 

List of Tables

 

Table 1.1          Construction Program

Table 2.1          Analytical Parameters and Methodology

Table 2.2          Emission Limit for Centralized Air Pollution Control Unit

Table 2.3          Emission Limit for Cogeneration Units

Table 2.4          Emission Limit for Standby Flaring Gas Unit

Table 2.5         Emission Limit for ASP

Table 2.6         Odour Intensity Level

Table 2.7          Action and Limit Levels for Odour Nuisance

Table 2.8          Event and Action Plan for Odour Monitoring

Table 6.1          Proposed Landscape and Visual Mitigation Measures for Construction Phase

Table 6.2          Proposed Landscape and Visual Mitigation Measures for Operation Phase


List of Figures

 

Figure 1.1     Location Plan of Proposed OWTF Phase I Development

Figure 1.2     Project Area Boundary of Proposed OWTF Phase I Development
Figure 1.3     New OWTF Layout Plan

Figure 1.4     Project Organization EM&A Programme for Construction Phase

Figure 1.5     Project Organization EM&A Programme for Operation Phase

Figure 1.6      Environmental Complaint Flow Diagram

 

 

List of Appendices

 

Appendix A     Implementation Schedule of Mitigation Measures

Appendix B     Sample of Incident Report on Action or Limit Level Non-compliance


1.       INTRODUCTION

Purpose of Manual

1.1             The Environmental Monitoring and Audit (EM&A) Manual was updated based on findings in Environmental Review Report (November 2015) submitted to EPD to support the Application for Variation for Environmental Permit (VEP-487/2015) and matched with the current Environmental Permit (FEP-01395/2010/C).

1.2             The purpose of this Environmental Monitoring and Audit (EM&A) Manual is to guide the setup of an EM&A programme for the implementation of the Environmental Impact Assessment (EIA) Study recommendations, to evaluate the effectiveness of the recommended mitigation measures and to identify any further need for additional mitigation measures or remedial action. This Manual outlines the EM&A programme for the construction and operation phases of the proposed Project, namely “Organic Waste Treatment Facilities Phase I (hereinafter referred to as “the Project”). It aims to provide systematic procedures for monitoring, auditing and minimising environmental impacts associated with construction works and operational activities.

 

1.3             Hong Kong environmental regulations and the Hong Kong Planning Standards and Guidelines have served as environmental standards and guidelines in the preparation of this Manual. In addition, the EM&A Manual has been prepared in accordance with the requirements stipulated in Annex 21 of the Technical Memorandum on the EIA Process (EIAO-TM).

 

1.4             This Manual contains the following information:

 

l   Responsibilities of the Contractor, the Supervising Officer (SO)[1], Supervising Officer’s representative (SOR)1,  Environmental Team (ET)[2],  the Independent Environmental Checker (IEC), Environmental Protection Department (EPD) and Monitoring Team (MT) with respect to the EM&A requirements during the course of the Project;

l   project organization for the Project;

 

l   the basis for, and description of the broad approach underlying the EM&A programme;

l   requirements with respect to the construction programme and the necessary EM&A programme to track the varying environmental impact;

l   methodologies to be adopted, including all field, laboratories and analytical procedures, and quality assurance and quality control programme (e.g. calibration of monitoring equipment);

l   definition of Action and Limit levels;

 

l   establishment of Event and Action plans;

l   procedures for environmental complaints handling;

 

l   requirements for reviewing pollution sources and working procedures required in the event of non-compliance with the environmental criteria and complaints;

l   requirements  for  presentation  of  EM&A  data  and  appropriate  reporting procedures; and

l   requirements for review of EIA predictions and the effectiveness of the mitigation measures / environmental management system and the EM&A programme.

 

1.5             For the purpose of this manual, the ET leader, who shall be responsible for and in charge of the ET, shall refer to the person delegated the role of executing the EM&A requirements.


Project Description

 

Introduction

 

1.6             The proposed Organic Waste Treatment Facilities (OWTF) Phase I development is to construct and build a biological treatment facility with a capacity of about 200 tonnes per day and convert the source-separated organic waste into compost and biogas through proven biological treatment technologies.

 

1.7             The OWTF Phase I development is proposed to be located in the Siu Ho Wan, North Lantau. The location plan of the Project is shown in Figure 1.1. The total area of the Project site is approximately 2 hectares and it is bounded northeast by North Lantau Highway and southeast by Siu Ho Wan Water Treatment Works (SHWWTW) located. The project area boundary of the OWTF Phase I development is shown in Figure 1.2.

 

Project Scope

 

1.8             The Project is planned to be implemented through a Design, Build and Operate (DBO) contract. A reference design for the OWTF Phase I development has been prepared, and the Contractor will be responsible for the detailed design of the facilities; provision and installation of the facilities; testing and commissioning of equipment; operation of the facilities; and monitoring of operation.

 

1.9             The preliminary layout plan of the proposed buildings and facilities in the Project site is shown in Figure 1.3. The key elements of OWTF Phase I developments include:

 

l   Pre-treatment facilities;

 

l   Anaerobic digestion process;

 

l   Post-treatment of digestate;

 

l   Energy recovery system; and

 

l   Air and wastewater treatment facilities.

 

1.10          The OWTF Phase I development will be operated in 24-hour basis daily, while the reception of organic waste would be 14 hours per day, tentatively.

Project Programme

 

1.11           The construction of OWTF Phase I was commenced in 2014. The OWTF is tentatively scheduled for commissioning by early 2017. The tentative project programme is shown in Table 1.1.


 

Table 1.1                        Construction Program

 

Description

Tentative Date

Site Handover to EPD

May 2011

Award of Contract

December 2014

Site Establishment and Temporary Works Preparation

December 2014– May 2015

Construction of OWTF Phase I and Ancillary Facilities

May 2015 Sept 2017

Testing and Commissioning

April November 2017

 

 

Project Organization

 

Introduction

 

1.12           The roles and responsibilities of the various parties involved in the construction phase and operation phase EM&A process and the implementation of the EM&A programme are outlined below. The proposed project organization and lines of communication during construction and operation phases with respect to environmental protection works are shown in Figure 1.4 and Figure 1.5 respectively.

 

Construction Phase

 

 Supervising Officer (SO) and Su per vising Officer’s Representative (SOR)

 

1.13           The term SO and SOR refers to the organization responsible for overseeing the construction works of the Project undertaken by the Contractor, and for ensuring that they are undertaken by the Contractor in accordance with the specification and contractual requirements.  The responsibilities for SO and SOR include the following:

 

l   Monitor the Contractor’s compliance with contract specifications, including the implementation and operation of the environmental mitigation measures and ensure their effectiveness, and other aspects of the EM&A programme;

l   Monitor the Contractor’s, the ET’s and the IEC’s compliance and ensure that the requirements in the Environmental Permit (EP) and EM&A Manual are fully complied with;

l    Provide assistance to the ET as necessary in the implementation of the M&A programme;

l    Participate in joint site inspection undertaken by the ET and the IEC;

 

l    Comply with the agreed Event / Action Plan in the event of any exceedance; and

 

l    Adhere to the procedures for carrying out complaint investigation.

 

Contractor

1.14           The term “Contractor” should be taken to mean all construction contractors and sub- contractors, working on site at any one time. Besides reporting to the SOR, the Contractor should also be responsible for the following tasks:

 

l   Work within the scope of the relevant contract and other tender conditions;

 

l    Provide assistance to the ET in carrying out monitoring;

 

l   Participate in the site inspections undertaken  by the ET  as required,  and undertake any corrective actions;

l   Provide information / advice to the ET regarding works activities which may contribute, or be continuing to the generation of adverse environmental conditions;

l   Submit proposals on mitigation measures in case of exceedances of Action or Limit levels in accordance with the Event / Action plans;

l   Implement measures to reduce impact where Action or Limit levels are exceeded; and

l    Adhere to the procedures for carrying out complaint investigation. Independent Environmental Checker (IEC)

1.15           The IEC should not be in any way an associated body of the Contractor for the Project.  The responsibilities for IEC should include the following:

 

l   Advise the SOR on environmental issues related to the Project, independent from the management of construction works, but empowered to audit the environmental performance of construction and operation;

l   Provide proactive advice to the SOR and the Employer of the Project on environmental matters;

l   Review and audit all aspects of the EM&A programme, including the implementation of environmental mitigation measures, submission relating to the EP and EM&A, and any other submission required under the EP and EM&A Manual;

l   Review and verify the monitoring data and all submissions relating to or under the EP and EM&A Manual submitted by the ET, including but not limited to the EM&A reports;

l   Monitor the implementation of the EM&A programme and the overall level of environmental performance being achieved;

l   Arrange and conduct regular, at least monthly site inspections of the works during construction phase, and ad hoc inspections if significant environmental problems are identified;

l    Comply with the agreed Event / Action Plan in the event of any exceedance;

 

l   Check and ensure the procedures for carrying out complaint investigation being followed and check the effectiveness of corrective measures;

l    Feedback audit results to ET by signing off relevant EM&A proforma;

 

l   Ensure the impact monitoring is conducted at the correct locations at the frequency identified in the EM&A Manual;

l    Check that the mitigation measures are effectively implemented; and

 

l    Report the works conducted, the findings, recommendation and improvement of the site inspections, the findings, recommendation, and improvement after reviewing the ET’s and the Contractor’s wor.ks, and any advices to the SOR and the Employer of the Project on a monthly basis.

 

Environmental Team

 

1.16           The ET shall not be in any way an associated body of the Contractor, and shall be responsible to conduct the EM&A programme. The ET should be managed by the ET Leader. The ET Leader shall be a person who has at least 7 years’ experience in EM&A and have relevant professional qualifications. Suitably qualified staff should be included in the ET, and resources for the implementation of the EM&A programme should be allocated in time under the Contract, to enable fulfilment of the Project’s EM&A requirements as specified in the EM&A Manual during construction of the Project.  The ET shall report to the SOR and the duties of ET shall include the following:

 

l   Monitor and audit various environmental parameters as required in this EM&A Manual;

l   Analyse the EM&A data and review the success of EM&A programme to cost- effectively confirm the adequacy of mitigation measures implemented and the validity of the EIA predictions and to identify any adverse environmental impacts arising;

l   Carry out regular site inspection to investigate and audit the Contractor’s site practice, equipment and work methodologies with respect to pollution control and environmental mitigation, and effect proactive action to pre-empt problems;

l   Monitor compliance with conditions in the EP, environmental protection, pollution prevention and control regulations and contract specifications;

l    Audit environmental monitoring data and site environmental conditions;

 

l   Report on the environmental monitoring and audit results to EPD, the SOR, the IEC and Contractor or their delegated representative;

l   Recommend suitable mitigation measures to the Contractor in the case of exceedance of Action or Limit levels in accordance with the event and action plans;

l   Liaise with the IEC on all environmental performance matters and timely submit all relevant EM&A proforma for approval by the IEC;

l   Advise the Contractor on environmental improvement, awareness, enhancement matters, etc., on site;

l    Adhere to the procedures for carrying out complaint investigation; and

 

l    Timely submit the EM&A Reports to the EPD.

 

1.17           Sufficient and suitably qualified professional and technical staff should be employed to ensure full compliance with their duties and responsibilities, as required under the EM&A programme during the construction phase of the Project.

 

Operation Phase

 

1.18           Under the DBO contract, the Contractor will be responsible for the operation of the OWTF. The Contractor shall ensure full compliance with the conditions of the EP during its operation. A Monitoring Team (MT) should be employed by the Contractor to carry out the monitoring works during the operation phase as required in this EM&A Manual.

 

1.19           The MT shall be managed by the MT Leader to analyze the monitoring results. The MT Leader shall be a person who has at least 7 years’ experience in EM&A and have relevant professional qualifications. Suitably qualified staff should be included in the MT, and resources for the implementation of the monitoring programme should be allocated in time under the Contract, to enable fulfilment of the Project’s monitoring requirements as specified in the EM&A Manual during operation of the Project.  The responsibilities for MT should include the following:

 

l   Monitor various environmental parameters as required in this EM&A Manual;

 

l   Report on the environmental monitoring results to the Contractor, the SOR, and the IEC;

l   Analyze monitoring results collected from the monitoring works;

 

l   Prepare monitoring reports to provide the impact evaluation results to the Contractor, the SOR and the IEC; and

l   Recommend suitable actions to the Contractor and SOR in case of exceedance of any assessment criteria.

 

Structure of this Manual

 

1.20           Following this introductory section, the structure of the EM&A Manual is set out below:-

 

l   Section 2 details the requirement for impact monitoring for dust during the construction phase and for air emission from OWTF and odour during the operation phase.

l   Section 3 details the audit requirements with regard to hazard to life issues.

 

l   Section 4           details the requirements for baseline and impact monitoring for water quality during the construction phase.

l   Section 5 details the audit requirements with regard to waste management issues as well as the waste control and mitigation measures recommended in the EIA.

l   Section 6           details the requirements with regard to landscape and visual issues.

 

l   Section 7     details the requirements with regard to noise issues

 

l   Section 8           details the requirements on site environmental audit and the environmental complaints handling procedure.

l   Section 9 details the EM&A reporting requirements.

 


 

2               AIR QUALITY

 

Introduction

2.1             This section presents the requirements, methodology, equipment, criteria and protocols for the monitoring and audit of air quality impacts during the construction and operational phases of the Project.

 

2.2             The objectives of the air quality monitoring include the following:-

 

l   to identify the extent of construction dust and operational odour impacts;

 

l   to determine the effectiveness of mitigation measures to control dust emission from activities during construction phase and odour control measures during operational phase;

l   to audit the compliance of the Contractor with regard to dust control, contract conditions and the relevant dust impact criteria;

l   to recommend further mitigation measures if found to be necessary; and

 

l   to comply with action and limit levels for air quality as defined in this Manual.

 

2.3             During construction phase of the Project, dust impacts would be the major air quality impacts. While during operation phase of the Project, stack emissions from the centralized air pollution control unit (CAPC), the cogeneration units, the ammonia stripping plant (ASP) and the standby flare would be the key environmental issue. Odour emission from the operation of OWTF would be another environmental issue.

 

Monitoring during Construction Phase

 

2.4             With the implementation of practicable dust suppression measures stipulated in the Air Pollution Control (Construction Dust) Regulation, adverse construction dust impact at the Air Sensitive Receiver (ASR) is not expected during construction of the Project. Yet, regular site environmental audits during the construction phase of the Project as described in Section 8 of this Manual should be conducted to ensure that the recommended dust suppression measures are implemented properly.

 

2.5             Mitigation measures for dust control have been recommended in the EIA Report and are listed below:

 

l   Use of regular watering, with complete coverage, to reduce dust emissions from exposed site surfaces and unpaved roads, particularly during dry weather;

l   Use of frequent watering for particularly dusty construction areas and areas close to ASRs;

 

l   Side enclosure and covering of any aggregate or dusty material storage piles to reduce emissions. Where this is not practicable owing to frequent usage, watering should be applied to aggregate fines;

 

l   Open stockpiles should be avoided or covered. Where possible, prevent placing dusty material storage piles near ASRs;

 

l   Tarpaulin covering of all dusty vehicle loads transported to, from and between site locations;

 

l   Establishment and use of vehicle wheel and body washing facilities at the exit points of the site;

 

l   Provision of wind shield and dust extraction units or similar dust mitigation measures at the loading points, and use of water sprinklers at the loading area where dust generation is likely during the loading process of loose material, particularly in dry seasons/ periods;

 

l   Imposition of speed controls for vehicles on unpaved site roads. 8 kilometers per hour is the recommended limit;

 

l   Where possible, routing of vehicles and positioning of construction plant should be at the maximum possible distance from ASRs;

 

l   Every stock of more than 20 bags of cement or dry pulverised fuel ash (PFA) should be covered entirely by impervious sheeting or placed in an area sheltered on the top and the 3 sides;

 

l   Cement or dry PFA delivered in bulk should be stored in a closed silo fitted with an audible high level alarm which is interlocked with the material filling line and no overfilling is allowed; and

 

l   Loading, unloading, transfer, handling or storage of bulk cement or dry PFA should be carried out in a totally enclosed system or facility, and any vent or exhaust should be fitted with an effective fabric filter or equivalent air pollution control system.

 

2.6             The Contractor shall be responsible for the design and implementation of these measures.

 

Monitoring during Commissioning Stage and Operation Phase

 

Stack Monitoring

 

2.7             Monitoring of air quality parameters of concern due to stack emissions from centralized air pollution control unit, the ammonia stripping plant, the cogeneration units and the standby flaring gas unit should be conducted during commissioning stage. During the operation phase of the Project, stack monitoring shall be installed for the centralized air pollution control unit, the ammonia stripping plant and the cogeneration units of OWTF.

 

2.8             The parameters for measurement and the analytical methods are listed in Table 2.1. It should be noted that the proposed sampling methods below are for reference only and should be subject to the approval of EPD.

 

Table 2.1                        Analytical Parameters and Methodology

 

Parameters

Method

Stacks to be Monitored

Gaseous and vaporous organic substances (including NMVOC)

USEPA Method 18

USEPA Method 0031

·       Centralized Air Pollution Control Unit

·        Cogeneration Units

·       Standby   Flaring   Gas

·       Ammonia Stripping Plant

Particulate

ISO 9096,

ASTM D3685-98,

USEPA Method 17

·       Centralized Air Pollution Control Unit

·        Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

Carbon monoxide

Combustion Gas Analyser

·       Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

NOx

USEPA Reference methods USEPA Method 7 and

associated methods

·       Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

SO2

USEPA Method 8

·       Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

HCl and HF

USEPA Method 26

A USEPA Method 13B sampling train

·       Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

Oxygen

Combustion Gas Analyser (chemical cell and paramagnetic)

·       Centralized Air Pollution Control Unit

·        Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

Velocity and Volumetric Flow

ISO 10780 and ISO 9096

·       Centralized Air Pollution Control Unit

·        Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

Water Vapour Content and Temperature

USEPA Method 4

·       Centralized Air Pollution Control Unit

·        Cogeneration Units

·       Standby   Flaring   Gas Unit

·       Ammonia Stripping Plant

Ammonia

USEPA CTM 027

·       Ammonia Stripping Plant

 

2.9             Necessary monitoring equipment and techniques should be provided and used to demonstrate that the process is properly operated and the emissions can be minimized to   meet   the   air   pollution   control   requirements   as   tabulated   in Tables   2.2, 2.3, 2.4 and 2.5 below.

 

Table 2.2       Emission Limit for Centralized Air Pollution Control Unit

 

Parameter

Emission Level (mg//Nm3)

VOCs (including NMVOC)

680

Dust (or Total Suspended Particulates)

6

Odour (including NH3 & H2S)

220 (1)

Note:               (1) The odour unit is ou/Nm3.

 

 

Table 2.3                         Emission Limit for Cogeneration Units

 

Parameter

Maximum Emission Level (mg//Nm3) (1)

Dust (or Total Suspended Particulates)

15

Carbon Monoxide

650

NOx

300

SO2

50

VOCs

150

HCl

10

HF

1

Note: (1) All values refer to an oxygen content in the exhaust gas of 6% and dry basis.

 


 

Table 2.4                        Emission Limit for Standby Flaring Gas Unit

 

Parameter

Maximum Emission Level (mg//Nm3) (1)

Dust (or Total Suspended Particulates)

5

Carbon Monoxide

100

NOx

200

SO2

50

VOCs

20

HCl

10

HF

1

Note:    (1) All values refer to an oxygen content in the exhaust gas of 11% and dry basis.

 

Table 2.5        Emission Limit for ASP

 

Parameter

Maximum Emission Level (mg//Nm3) (1)

Dust (or Total Suspended Particulates)

5

Carbon Monoxide

100

NOx

200

SO2

50

VOCs

20

NH3

35

HCl

10

HF

1

Note: (1) All values refer to an oxygen content in the exhaust gas of 11% and dry basis.

                                   

 

2.10           On-line monitoring should be carried out for centralized air pollution control unit, cogeneration and ASP units during the operation phase of the OWTF. The continuous monitoring data should be transmitted instantaneously to EPD by telemetry system in such manner and the format to be agreed with EPD. The record should be retained at the premises for a minimum of two years, or other period specified by EPD, after the date of last entry and be made available for examination as and when required by EPD.

 

2.11        Evidence should be provided to demonstrate quality assurance procedures are in place to ensure all monitoring results are sufficiently accurate and reliable. Calibration on the monitoring equipment has to be done by means of parallel measurements with the reference methods as agreed by EPD.

 

2.12           The on-line monitoring of the in-stack exhaust gas shall be carried out. The continuous monitoring data should be transmitted instantaneously to EPD by telemetry system in such manner and format agreed with EPD. The  parameters to be continuously monitored are listed below:

 

l nitrogen oxides

 

l hydrogen chloride

 

l hydrogen fluoride

 

l sulphur dioxide

 

l ammonia

 

l gaseous and vaporous organic substances

 

l carbon monoxide

 

l oxygen

 

l pressure

 

l temperature

 

l water vapour content (continuous measurement of the water vapour content should not be required if the sample exhaust gas is dried before the emissions are analysed.)

 

Odour Monitoring

 

Commissioning Stage

 

2.13           Odour sampling works should be conducted weekly in the first month of the commissioning stage of the Project. The air samples at the stack of Centralized Air Pollution Control Unit under full capacity of operation should be collected for olfactometry analysis. Duplicate samples should be collected for each sampling exercise.

 

2.14           The following items should be recorded during sampling:

 

l   the prevailing weather condition;

 

l   the wind direction;

 

l   any odour detected  during  sampling and the  flavours  of  odour with detailed description of characteristics (e.g. sewage or rotten-egg smell, decayed vegetables, ammonical, dischargeable odour, putrefaction, sharp, pungent, fish, irritating, fruit, vinegar, etc);

 

l   downwind or upwind direction from the odour source;

 

l   duration of odour (intermittent or continuous) during sampling; and

 

l   photo showing the sampling locations relative to existing land features The relevant meteorological data (e.g. ambient temperature, wind speed and direction, etc.) from the nearest Hong Kong Observatory station during the sampling period should also be recorded for reference.

2.15           The collected air samples should be delivered to the laboratory for olfactometry analysis within 24 hours.

 

2.16           The odour concentration of the collected air samples should be determined by a forced- choice dynamic olfactometer with a panel of human assessors being the sensor in accordance with the European Standard Method: Air Quality Determination of Odour Concentration by Dynamic Olfactometry (EN13725) within 24 hours after collection.

 

2.17           The odour laboratory should be ventilated to maintain an odour-free environment and to provide fresh air to the panel members. Each odour testing session should comprise at least five qualified panellists. All of the panellists should be screened beforehand by using 50 ppm solution/mixture of certified n-butanol standard gas.

 

2.18           During each odour sampling day, one blank sample should be collected for quality control. The sample should be taken by purging pure nitrogen gas into the odour bag directly on site as a blank sample.

 

2.19           The olfactometry analysis should be conducted by the testing laboratories complying with the European Standard EN13725:2003. The laboratories should provide the QA/QC results in the laboratory analysis report.

 

Operation Phase

 

2.20           To determine the effectiveness of the proposed odour mitigation measures and to ensure the odour impacts arising from operation of the OWTF and the on-site wastewater treatment unit meeting the air pollution control requirements, odour patrol shall be conducted.

 

2.21           The odour patrols shall be conducted by an odour patrol team. The odour patrol team will patrol and sniff along an odour patrol route at the OWTF site boundary as shown in Figure 1.2. The implementation of the odour patrol shall be subject to the prevailing weather forecast condition and no odour patrol should be carried out during rainy day. The odour patrol team should be comprised of at least two independent trained personnel / competent persons, who should pass a set of screening tests and fulfil the following requirements: