1.1.1 Surface water falling within the northern catchments of Hong Kong Island is intercepted by a series of existing drainage pipes and culverts running through the urban area that ultimately discharge at several locations into Victoria Harbour. The existing system is overloaded and flooding and hazardous overland water flows can occur in extreme conditions. However, much of the catchment^{^[1]} is outside the urban area and the objective of the drainage improvement scheme studied here is to intercept surface water before it enters the urban area and direct it to a discharge outlet on the west-side of Hong Kong Island. This will reduce the flows entering into lower catchment and reduce flooding frequency in the urban area.

1.1.2 The study under Agreement No. CE91/95 identified a tunnel alignment to intercept flows and direct them to the tunnel. Due to the proximity of the tunnel alignment to Country Parks it was determined that the project would be classified as a Designated Project (DP) falling under the requirements of the Environmental Impact Assessment Ordinance (EIAO). It has included the Environmental Impact Assessment (EIA) Study.

1.1.3 Black & Veatch Hong Kong Ltd. (B&V) was commissioned by the Drainage Services Department (DSD) in October 2002 under Agreement No. CE 25/2002 (DS) to undertake the Drainage Improvement in Northern Hong Kong Island - Hong Kong West and Lower Catchment Improvement - Investigation Study. The investigation includes a review of the extent and alignments of the drainage tunnels together with its associated drainage structures (e.g. the intake shafts and connecting adits between the shafts and tunnels). An Environmental Impact Assessment (EIA) Study has been undertaken to provide information on the nature and extent of environmental impacts arising from the construction and operation of the proposed DP project and related activities. From the EIA, the recommendations for monitoring contained herein, are made. Figure 1.1 shows the layout of the Project.

1.1.4 The proposed tunnel starts from a tunnel portal close to the site of the Haw Par Mansion in Tai Hang and follows a sinuous route beneath urban areas in Jardines Lookout and Mid Levels. A discharge portal at the west end of Hong Kong Island at Pokfulam, north of the Cyberport site is proposed. The tunnel is designed to convey the intercepted flood flows for a 200-year storm event occurring across the complete catchment. The internal diameter of the initial section of the tunnel, before the Aberdeen Vehicular Tunnel, is 6.25m, while the remaining tunnel section has an internal diameter of 7.25m. Thirty five intake locations have been identified within the project areas that are suitable for intercepting flood flows. The intakes structures are interconnected with the main tunnel by connecting adits which are 2.3m in diameter. Figure 1.1 shows the alignment of the proposed tunnel, adits and the locations of the intake structures.

1.2 Purpose of this Manual

1.2.1 The purpose of this Environmental Monitoring and Audit (EM&A) Manual is to guide the setup of an EM&A programme to ensure compliance with the recommendations in the EIA study, to assess the effectiveness of the recommended mitigation measures and to identify any further need for additional mitigation measures or remedial action.

1.2.2 This Manual outlines the monitoring and audit programme to be undertaken for the construction and operational phases of the proposed DP. It aims to provide systematic procedures for monitoring, auditing and minimising of the environmental impacts associated with the project.

1.2.3 Hong Kong environmental regulations for noise, air quality, water quality and waste, the Hong Kong Planning Standards and Guidelines (HKPSG), and recommendations in the EIA Report have served as environmental standards and guidelines in the preparation of this Manual.

1.2.4 For the purpose of this Manual, the "Engineer" should refer to the Engineer as defined in the Contract and the Engineer's Representative (ER), in cases where the Engineer's powers have been delegated to the ER, in accordance with the Contract. The Environmental Team (ET) leader, who should be responsible for and in charge of the ET, should refer to the person delegated the role of executing the environmental monitoring and audit requirements.

1.2.5 This Manual contains the following:

· Duties of the ET with respect to the environmental monitoring and audit requirements during construction;

· Duties of the Independent Environmental Checker (IEC) with respect to the environmental monitoring and audit requirements during construction;

· Information on project organisation and programming of construction activities for the project;

· Requirements with respect to the construction schedule and the necessary environmental monitoring and audit programme to track the varying environmental impacts;

· Definition of Action and Limit Levels;

· Establishment of event and action plans;

· Requirements of reviewing pollution sources and working procedures required in the event of non-compliance of the environmental criteria; and

· Requirements of presentation of environmental monitoring and audit data and appropriate reporting procedures.

1.3 Environmental Monitoring and Audit Requirements

1.3.1 The construction and operation phase impacts of the DP have been assessed and presented in the EIA Report. The EIA Report has specified the recommended environmental mitigation measures to minimise the potential adverse environmental impacts identified. An implementation schedule of the recommended environmental mitigation measures is prepared as part of the EIA study and is contained in Appendix A of this Manual.

1.3.2 In order to ensure that the mitigation measures recommended in EIA Report are fully implemented and resulted in the expected effectiveness, this Manual defines the scope of EM&A requirements for the construction and operation of the DP to achieve satisfactory environmental performance. The EM&A requirements are prepared in accordance with the requirements stipulated in Annex 21 of the Technical Memorandum on Environmental Impact Assessment Process (EIA-TM). The environmental monitoring to be undertaken for the DP are as follows:-

· Baseline Monitoring refers to the measurement of prevailing environmental parameters, including existing air quality and noise level, to determine the nature and ranges of natural variation and to establish, where appropriate, the nature of change. This information is useful for assessing the short and long term environmental impacts of the Project activities.

· Impact Monitoring involves the measurement of environmental parameters during the Project activities in order to determine the impacts of the activities and the effectiveness of the proposed mitigation measures, and any further remedial measures which are needed.

· Compliance Monitoring involves periodic sampling and/or continuous measurement of environmental parameters and the determination of their compliance with regulatory requirements and standards.

1.3.3 The environmental monitoring programme shall also be subject to environmental audit. The aim is to determine whether satisfactory compliance with the legislative requirements has been met, and to ensure that no annoyance is caused to sensitive receivers or else the remedial action plan will be initiated, if required. This will require information on the standards for parameters of concern and monitoring data. Each audit will consist of a review of the monitoring data and comparison with the relevant legislative requirements and environmental performance standards specified in the Contract Document.

1.3.4 In order to ensure that the mitigation measures recommended in the EIA study are implemented fully and resulted in the expected effectiveness, this Manual defines the scope of EM&A requirements for the construction of the proposed DP to achieve satisfactory environmental performance. The EM&A requirements for the DP shall be as follows:-

· Pre-Construction Phase – including all baseline monitoring prior to any project activity occurring on site.

· Construction Phase – including impact/compliance monitoring and audit during all construction activities.

· Operation Phase – including ground water level monitoring and audit at selected intakes/drop shafts locations.

1.4 Project Organization

1.4.1 The proposed EM&A organization is shown in Figure 1.2 of this Manual. The responsibilities of respective parties for the EM&A programme during the pre-construction and construction are listed in forthcoming Clauses.

Environmental Team

1.4.2 The ET Leader and the ET should not be in any way an associated body of the Contractor. The ET should be led and managed by the ET Leader. The ET Leader shall be the person who has at least 7 years' experience in EM&A or environmental management.

1.4.3 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 fulfillment of the project's EM&A requirements as specified in the EM&A Manual during construction. The project proponent should be responsible for the EM&A requirements as specified in this EM&A manual during operation phase of the proposed project.

1.4.4 The ET Leader and the ET are employed to implement the EM&A programme and ensure the Contractor's compliance with the project's environmental performance requirements during construction. The duties are:

(a) sampling, analysis and statistical evaluation of monitoring parameters as required in the EM&A Manual;

(b) carry out environmental site surveillance;

(d) monitor the implementation of environmental mitigation measures;

(e) monitor the compliance with Conditions in the relevant Environmental Permit (EP) and compliance with Specifications in the Contract;

(f) review the construction programme and comment as necessary;

(g) review the construction methodology and comment as necessary;
preparation and updating of EM&A works schedule with reference to the best available detailed construction programme;

(h) investigation of non-compliant events, evaluation and identification of corrective measures;

(i) liaison with IEC on all environmental performance matters, and timely submission of all relevant EM&A proforma for the approval by IEC;

(j) advice to the Contractor on environment improvement, awareness, enhancement matters, etc., on site and

(k) timely submission of the EM&A report to the project proponent and the DEP.

1.4.5 Site inspections should be carried out by the ET at least once per week during construction. Ad hoc site inspections should also be carried out if significant environmental problems are identified.

Independent Environmental Checker

1.4.6 The IEC should advise the ER on environmental issues related to the project. The role of the IEC should be independent from the management of construction works, but the IEC should be empowered to audit the environmental performance of construction.

1.4.7 The IEC should be employed prior to commencement of construction of the project. The IEC should have at least 7 years experience in EM&A or environmental management. The appointment of the IEC is subject to the approval of the Engineer.

1.4.8 The IEC should audit the overall EM&A programme including the implementation of all environmental mitigation measures, submissions relating to EM&A, and any other submission required under this Manual. In addition, the IEC should be responsible for verifying the environmental acceptability of permanent and temporary works, and relevant design plans and submissions under this Manual.

1.4.9 The IEC should arrange and conduct at least monthly general site inspections of the project during the construction periods. Ad hoc site inspection should also be carried out if significant environmental problems are identified.

1.4.10 The IEC should ensure the impact monitoring is conducted according to the prescribed schedule at the correct locations.

1.4.11 The IEC should report the findings of the site inspections and other environmental performance reviews to DSD and Engineer/ER.

1.4.12 Appropriate resources should also be allocated under the Contract for the IEC to fulfill their duties specified in this Manual.

1.4.13 The main duty of the IEC is to carry out environmental audit of the construction of the project; this should include, inter alias, the followings:

(a) review and audit all aspects of the EM&A programme;

(b) advise on proactive actions;

(c) validate and confirm the accuracy of monitoring results, monitoring equipment, monitoring locations, monitoring procedures and locations of sensitive receivers;

(d) carry out random sample check and audit on monitoring data and sampling procedures, etc.;

(e) conduct random site inspection;

(f) audit the recommendations and requirements in EIA Report against the status of implementation of environmental protection measures on site;

(g) review the effectiveness of environmental mitigation measures and project environmental performance;

(h) on a needs basis, audit the Contractor's construction methodology and agree the least impact alternative in consultation with the ET Leader and the Contractor;

(i) investigate complaint cases and check the effectiveness of corrective measures;

(j) review accuracy of environmental monitoring section of EM&A reports;

(k) verify EM&A report submitted by the ET Leader;

(l) feedback audit results to ET by signing off relevant EM&A proformas.

Contractors

1.4.14 The term "Contractors" should be taken to mean all construction contractors and sub-contractors, working on site at any one time. Besides reporting to the Engineer, the Contractors should:

(a) provide assistance to ET in carrying out monitoring;

(b) work within the scope of the relevant contract and conditions;

(c) participate in the site inspections undertaken by the ET, as required, and undertake any correction actions instructed by the Engineer;

(d) provide information/advice to the ET regarding works activities which may contribute, or be continuing to the generation of adverse environmental conditions;

(e) implement measures to reduce impact whenever Action and Limit Levels are exceeded;

(f) take responsibility and strictly adhere to the guidelines of the EM&A programme and complementary protocols developed by their project staff; and

(g) adhere to the procedures for carrying out complaint investigation in accordance with EM&A manual

Engineer or Engineer's Representative (ER)

1.4.15 The term Engineer, or Engineer's Representative, refers to the organization responsible for overseeing the construction works of the project and 'monitoring' the works undertaken by the various Contractors, and for ensuring that they are undertaken by the Contractors in accordance with the specification and contractual requirements. The ER should:

(a) monitor the Contractors' compliance with contract specifications, including the implementation and operation of environmental mitigation measures and ensure their effectiveness, and other aspects of the EM&A programme;

(b) inform the Contractor when action is required to reduce impacts in accordance with the Event and Action Plan;

(c) provide assistance to the ET as necessary in the implementation of the environmental monitoring and auditing programme;

(d) adhere to the procedures for carrying out complaint investigation in accordance with EM&A manual; and

(e) instruct the Contractors to follow the agreed protocols or those in the Contract Specifications in the event of exceedances of Action and Limit levels;

1.5 Construction Programme

1.5.1 The major construction activities of the Project are tunneling works, drilling & blasting works, excavation and concreting works for the intakes structure, stilling basins and tunnel portals.

1.5.2 During the operation stage, the major site activities are the maintenance work of the main drainage tunnel, adits, intake structures and the ancillary facilities.

1.5.3 The construction of the Project is scheduled for commencement in mid 2007 for completion in end 2011. A tentative construction programme is provided in Appendix F. The ET and IEC shall make reference to the Contractor’s actual works progress and works programme during the construction stage to schedule the EM&A works, and the Contractor shall provide the respective information to the ET Leader and the IEC for formulating the EM&A schedule.

2. AIR QUALITY

2.1 Air Quality Monitoring Parameters

2.1.1 The construction of the Project is scheduled for commencement in mid 2007 for completion in end 2011. A tentative construction programme is provided in Appendix F. The ET and IEC shall make reference to the Contractor’s actual works progress and works programme during the construction stage to schedule the EM&A works, and the Contractor shall provide the respective information to the ET Leader and the IEC for formulating the EM&A schedule.

2.1.2 Monitoring and audit of the Total Suspended Particulates (TSP) levels shall be carried out by the ET to ensure that any deteriorating air quality could be readily detected and timely action taken to rectify the situation.

2.1.3 1-hour and 24-hour TSP levels shall be measured to indicate the impacts of construction dust on air quality. The TSP levels shall be measured by following the standard high volume sampling method as set out in the Title 40 of the Code of Federal Regulations, Chapter 1 (Part 50), Appendix B. Upon approval by the ER, 1-hour TSP levels can be measured by direct reading methods which are capable of producing comparable results as that by the high volume sampling method, to indicate short event impacts.

2.1.4 All relevant data including temperature, pressure, weather conditions, elapsed-time meter reading for the start and stop of the sampler, identification and weight of the filter paper, and other special phenomena and work progress of the concerned site etc. shall be recorded down in details. A sample field log sheet is shown in Appendix B to this Manual.

2.2 Monitoring Equipment

2.2.1 High Volume Sampler (HVS) in compliance with the following specifications shall be used for carrying out the 1-hour and 24-hour TSP monitoring:

· 0.6-1.7m³/min (20-60 SCFM) adjustable flow range;

· equipped with a timing/control device with +/- 5 minutes accuracy for 24 hours operation;

· installed with elapsed-time meter with +/- 2 minutes accuracy for 24 hours operation;

· capable of providing a minimum exposed area of 406 cm² (63in²);

· flow control accuracy: +/- 2.5% deviation over 24-hour sampling period;

· equipped with a shelter to protect the filter and sampler;

· incorporated with an electronic mass flow rate controller or other equivalent devices;

· equipped with a flow recorder for continuous monitoring;

· provided with a peaked roof inlet;

· incorporated with a manometer;

· able to hold and seal the filter paper to the sampler housing at horizontal position;

· easy to change the filter; and

· capable of operating continuously for 24-hour period.

2.2.2 The ET Leader shall be responsible for provision of the monitoring equipment and associated accessories and power supply. He shall ensure that sufficient numbers of HVSs with an appropriate calibration kit are available for carrying out the regular impact monitoring and ad hoc monitoring. The HVSs shall be equipped with an electronic mass flow controller and be calibrated against a traceable standard at regular intervals. All the equipment, calibration kit, filter papers, etc. shall be clearly labeled. The ET Leader shall also liaise with the concerned parties for gaining access to the monitoring stations for the installation of the monitoring equipment and carrying out monitoring.

2.2.3 Initial calibration of dust monitoring equipment shall be conducted upon installation and thereafter at bi-monthly intervals. The transfer standard shall be traceable to the internationally recognized primary standard and be calibrated annually. The calibration data shall be properly documented for future reference by the concerned parties such as IEC. All the data should be converted into standard temperature and pressure condition.

2.2.4 The flow-rate of the sampler before and after the sampling exercise with the filter in position shall be verified to be constant and be recorded in the field log sheet mentioned in Section 2.3.

2.2.5 If the ET Leader proposes to use a direct reading dust meter to measure 1-hour TSP levels, he shall submit sufficient information to the IEC to prove that the instrument is capable of achieving a comparable result as that the HVS and may be used for the 1-hour sampling. The instrument shall also be calibrated regularly, and the 1-hour sampling shall be determined periodically by HVS to check the validity and accuracy of the results measured by direct reading method.

2.2.6 Wind data monitoring equipment shall also be provided and set up at conspicuous locations for logging wind speed and wind direction near to the dust monitoring locations. The equipment installation location shall be proposed by the ET Leader and agreed with the ER in consultation with the IEC. For installation and operation of wind data monitoring equipment, the following points shall be observed:-

· the wind sensors should be installed on masts at an elevated level 10m above ground so that they are clear of obstructions of turbulence caused by the buildings;

· the wind data should be captured by a data logger and to be downloaded for processing at least once a month;

· the wind data monitoring equipment should be re-calibrated at least once every six months; and

· wind direction should be divided into 16 sectors of 22.5 degrees each.

2.2.7 In exceptional situations, the ET Leader may propose alternative methods to obtain representative wind data. The alternative methods shall be agreed by ER in consultation with the IEC.

2.3 Laboratory Measurement/Analysis

2.3.1 The ET Leader shall carry out laboratory measurements/analyses for the dust samples collected.

2.3.2 A clean laboratory with constant temperature and humidity control, and equipped with necessary measuring and conditioning instruments, to handle the dust samples collected, shall be available for sample analysis, and equipment calibration and maintenance. The laboratory shall be Hong Kong Laboratory Accreditation Scheme (HOKLAS) accredited.

2.3.3 If a site laboratory is set up or a non-HOKLAS accredited laboratory is hired for carrying out the laboratory analysis, the laboratory equipment shall be approved by the ER and the measurement procedures shall be witnessed by the ER. The ET Leader shall provide the ER with one copy of the Title 40 of the Code of Federal Regulations, Chapter 1 (Part 50), Appendix B for his reference.

2.3.4 Filter paper of size 8”´10” shall be labeled before sampling. It shall be a clean filter paper with no pin holes, and shall be conditioned in a humidity controlled chamber for over 24-hour and be pre-weighed before use for the sampling.

2.3.5 After sampling, the filter paper loaded with dust shall be kept in a clean and tightly sealed plastic bag. The filter paper is then returned to the laboratory for reconditioning in the humidity controlled chamber followed by accurate weighing by an electronic balance with a readout down to 0.1 mg. The balance shall be regularly calibrated against a traceable standard.

2.3.6 All the collected samples shall be kept in a good condition for 6 months before disposal.

2.4 Monitoring Locations

2.4.1 Two designated monitoring stations, AQ1 and AQ2 are selected for dust impact monitoring as they are the representative air sensitive receivers very close to the construction works areas. Table 2.1 describes the air quality monitoring locations, which are also depicted in Figures 2.1 and 2.2.

Table 2.1 Locations for Air Quality Monitoring Stations

Monitoring Stations	Figure no.	Location
AQ1	2.1	True Light Middle School of Hong Kong
AQ2	2.2	Aegean Terrace

2.4.2 The status and locations of dust sensitive receivers may change after issuing this Manual. If such cases exist, the ET Leader shall propose updated monitoring locations, which shall be approved by the ER and agreed with IEC.

2.4.3 When alternative monitoring locations are proposed, the following criteria, as far as practicable, shall be followed:-

· at the site boundary or such locations close to the major dust emission source;

· close to the sensitive receptors; and

· take into account the prevailing meteorological conditions.

2.4.4 The ET Leader shall agree with the ER on the position of the High Volume Sampler for installation of the monitoring equipment. When positioning the samplers, the following points shall be noted:

· a horizontal platform should be provided with appropriate support to secure the samplers against gusty wind;

· no two samplers should be placed less than 2 meters apart;

· the distance between the sampler and an obstacle, such as buildings, should be at least twice the height that the obstacle protrudes above the sampler;

· a minimum of 2 meters separation from walls, parapets and penthouses is required for rooftop samples;

· a minimum of 2 meters separation from any supporting structure, measured horizontally is required;

· no furnaces or incineration flues or building vents are nearby;

· airflow around the sampler is unrestricted;

· the sampler is more than 20 meters from the drip line;

· any wire fence and gate, to protect the sampler, should not cause any obstruction during monitoring;

· permission must be obtained to set up the samplers and to obtain access to the monitoring stations; and

· a secured supply of electricity is needed to operate the samplers.

2.5 Baseline Monitoring

2.5.1 Baseline monitoring shall be carried out at all the designated monitoring locations for at least 14 consecutive days prior to the commissioning of the construction works to obtain daily 24-hour TSP samples. 1-hour TSP sampling shall also be done at least 3 times per day while highest dust impact is expected. Before commencing the baseline monitoring, the ET leader shall inform the IEC of the baseline monitoring programme such that the IEC can conduct on-site audit to ensure accuracy of the baseline monitoring results.

2.5.2 During the baseline monitoring, there should not be any construction or dust generation activities in the vicinity of the monitoring stations.

2.5.3 In case the baseline monitoring cannot be carried out at the designated monitoring locations during the baseline monitoring period, monitoring shall be carried out at alternative locations which can effectively represent the baseline conditions at the impact monitoring locations. The alternative baseline monitoring locations shall be approved by the ER and agreed with IEC.

2.5.4 In exceptional case, when insufficient baseline monitoring data or questionable results are obtained, the ET Leader shall liaise with IEC to agree on an appropriate set of data to be used as a baseline reference and submit to ER for approval.

2.5.5 Ambient conditions may vary seasonally and shall be reviewed at three monthly intervals. If the ET Leader considers that the ambient conditions have been changed and repeat of the baseline monitoring is required to be carried out for obtaining the updated baseline levels, the monitoring should be conducted at times when the Contractor’s activities are not generating dust, at least in the proximity of the monitoring stations. Should changes in ambient conditions be determined, the baseline levels and, in turn, the air quality criteria, should be revised. The revised baseline levels and air quality criteria should be agreed with IEC and EPD.

2.6 Impact Monitoring

2.6.1 The ET Leader shall carry out impact monitoring during the course of the Project activities under the Contract. For regular impact monitoring, the sampling frequency of at least once in every six-day, shall be strictly observed at all the monitoring stations for 24-hour TSP monitoring. For 1-hour TSP monitoring, the sampling frequency of at least three times in every six-day should be undertaken when the highest dust impact occurs.

2.6.2 The specific time to start and stop the 24-hr TSP monitoring shall be clearly defined for each location and be strictly followed by the operator.

2.6.3 In case of non-compliance with the air quality criteria, more frequent monitoring exercise, as specified in the Event/Action Plan in Section 2.7 shall be conducted within 24 hours after the result is obtained. This additional monitoring shall be continued until the excessive dust emission or the deterioration in air quality is rectified.

2.7 Event and Action Plan for Air Quality

2.7.1 The baseline monitoring results form the basis for determining the air quality criteria for the impact monitoring. The ET Leader shall compare the impact monitoring results with air quality criteria set up for 24-hour TSP and 1-hour TSP. Table 2.2 below shows the air quality criteria, namely Action and Limit levels to be used. Should non-compliance of the air quality criteria occur, actions in accordance with the Event/Action Plan in Table 2.3 shall be carried out.

Table 2.2 Action and Limit Levels for Air Quality

Parameters	Action	Limit
24 Hour TSP Level in µg/m³	For baseline level ≤ 200 µg/m³, Action level = (Baseline level *1.3 + Limit level)/2 For baseline level > 200 µg/m³, Action level = Limit level	260
1 Hour TSP Level in µg/m³	For baseline level ≤ 384 µg/m³, Action level = (Baseline level * 1.3 + Limit level)/2 For baseline level > 384 µg/m³, Action level = Limit level	500

Parameters

Action

Limit

24 Hour TSP Level in µg/m³

For baseline level ≤ 200 µg/m³,

Action level = (Baseline level *1.3 + Limit level)/2

For baseline level > 200 µg/m³,

Action level = Limit level

260

1 Hour TSP Level in µg/m³

For baseline level ≤ 384 µg/m³,

Action level = (Baseline level * 1.3 + Limit level)/2

For baseline level > 384 µg/m³,

Action level = Limit level

500

Table 2.3 Event/Action Plan for Air Quality

	ACTION
EVENT	ET	IEC	ER	CONTRACTOR
ACTION LEVEL
1.Exceedance for one sample	1. Identify the source and investigate the causes and propose remedial measures 2. Inform ER & IEC 3. Repeat measurement to confirm finding 4. Increase monitoring frequency to daily	1. Check monitoring data submitted by ET 2.Check Contractor's working methods	1.Notify Contractor	1.Rectify any unacceptable practice 2.Amend working methods if appropriate
2.Exceedance for two or more consecutive samples	1. Identify the source 2. Inform ER & IEC 3. Repeat measurements to confirm findings 4. Increase monitoring frequency to daily 5. Discuss with ER & IEC for remedial actions required 6. If exceedance continues, arrange meeting with ER & IEC 7. If exceedance stops, cease additional monitoring	1.Checking monitoring data submitted by ET 2. Check Contractor's working methods 3. Discuss with ET, IEC and Contractor on proposed remedial actions 4. Advise the ER & ET on the effectiveness of the proposed remedial measures 5.Supervise the implementation of the remedial measures	1.Confirm receipt of notification of failure in writing 2.Notify Contractor 3.Ensure remedial actions properly implemented	1.Submit proposals for remedial actions to ER within 3 working days of notification 2.Implement the agreed proposals 3.Amend proposal if appropriate
LIMIT LEVEL
1.Exceedance for one sample	1. Identify source,,investigate the causes and propose remedial measures 2. Inform ER & IEC and EPD 3. Repeat measurement to confirm finding 4. Increase monitoring frequency to daily 5. Assess effectiveness of Contractor's remedial actions and keep EPD and ER & IEC informed of the results	1.Check monitoring data submitted by ET 2. Check Contractor's working methods 3. Discuss with ET and Contractor on proposed remedial actions 4. Advise the ER on the effectiveness of the proposed remedial measures 5.Supervise the implementation of the remedial measures	1.Confirm receipt of notification of failure in writing 2.Notify Contractor 3.Ensure remedial actions properly implemented	1.Take immediate action to avoid further exceedance 2.Submit proposals for remedial actions to ER within 3 working days of notification 3.Implement the agreed proposals 4.Amend proposal if appropriate
2.Exceedance for two or more consecutive samples	1. Identify source 2. Inform ER, IEC and EPD the causes & actions taken for the exceedances 3. Repeat measurement to confirm findings 4. Increase monitoring frequency to daily 5. Investigate the causes of exceedance 6. Arrange meeting with & IEC and ER to discuss the remedial actions to be taken 7. Assess effectiveness of Contractor's remedial actions and keep ER, IEC and EPD informed of the results 8. If exceedance stops, cease additional monitoring	1.Discuss amongst ER, ET and Contractor on the potential remedial actions 2.Review Contractor’s remedial actions to assure their effectiveness and advise the ER accordingly 3.Supervise the implementation of the remedial measures	1.Confirm receipt of notification of failure in writing 2.Notify Contractor 3.In consultation with the IEC, agree with the Contractor on the remedial measures to be implemented 4.Ensure remedial measure are properly implemented 5.If exceedance continues, consider what portion of the work is responsible and instruct the Contractor to stop that portion of work until the exceedance is abated	1. Take immediate action to avoid further exceedance 2. Submit proposals for remedial actions to ER within 3 working days of notification 3. Implement the agreed proposals 4. Resubmit proposals if problem still not under control 5. Stop the relevant portion of works as determined by the ER until the exceedance is abated

3. NOISE

3.1 Noise Monitoring Parameters

3.1.1 The construction noise levels shall be measured in terms of the A-weighted equivalent continuous sound pressure level (Leq). Leq(30 min) shall be used as the monitoring parameter for the time period between 0700-1900 hours on normal weekdays. A supplementary information for data auditing, statistical results such as L₁₀ and L₉₀ shall also be obtained for reference. For all other time periods, Leq(5 min) shall be employed for comparison with the Noise Control Ordinance (NCO) criteria.

3.2 Monitoring Equipment

3.2.1 As referred to in the Technical Memorandum (TM) issued under the NCO, sound level meters in compliance with the International Electrotechnical Commission Publications 651: 1979 (Type 1) and 804: 1985 (Type 1) specifications shall be used for carrying out the noise monitoring. Immediately prior to and following each noise measurement the accuracy of the sound level meter shall be checked using an acoustic calibrator generating a known sound pressure level at a known frequency. Measurements may be accepted as valid only if the calibration levels from before and after the noise measurement agree to within 1.0dB.

3.2.2 Noise measurements shall not be made in the presence of fog, rain, wind with a steady speed exceeding 5ms^-1 or wind with gusts exceeding 10ms^-1. The wind speed shall be checked with a portable wind speed meter capable of measuring the wind speed in m/s. Sample noise field data sheet is shown in Appendix C to this Manual for reference.

3.2.3 The ET Leader shall be responsible for the provision of the monitoring equipment and associated accessories and power supply. He shall ensure that sufficient noise measuring equipment and associated instrumentation are available for carrying out the regular impact monitoring and ad hoc monitoring. All the equipment and associated instrumentation shall be clearly labelled. The ET Leader shall also liaise with the concerned parties for gaining access to the monitoring stations for the installation of the monitoring equipment and carrying out monitoring.

3.3 Monitoring Locations for Airborne Construction Noise

3.3.1 Twenty-one designated monitoring stations, NC1 to NC21 are selected for construction noise monitoring. Table 3.1 describes the construction noise monitoring locations, which are also depicted in Figures 2.1, 2.2 and 3.1-3.16. The status and locations of noise sensitive receivers may change after issuing this manual. If such cases exist, the ET Leader shall propose updated monitoring locations and seek approval from ER and agreement from the IEC of the proposal.

Table 3.1 Locations for Airborne Construction Noise Monitoring Stations

Location	Fig. no.	Monitoring Stations	Descriptions	Status
Eastern Portal	2.1	NC1	True Light Middle School of Hong Kong	School
Eastern Portal	2.1	NC2	The Legend (Future development)	Domestic Premises
Western Portal	2.2	NC3	Aegean Terrance	Domestic Premises
Intakes BR6(P)	3.1	NC4	Man Yuen Garden	Domestic Premises
Intakes BR7(P)	3.1	NC5	16 Caronia	Domestic Premises
Intake DG1(P)	3.2	NC6	Blk C Villa Monte Rosa	Domestic Premises
Intake DG1	3.3	NC7	Rosaryhill School	School
Intake E5(A)(P)	3.3	NC8	Buddist Li Ka Shing Care & Attention Home for the Elderly	Domestic Premises
Intake E7(P)	3.4	NC9	Marymount Secondary School	School
Intake E7(P)	3.4	NC10	117 Blue Pool Road	Domestic Premises
Intakes MA13(P) & MA14(P)	3.5	NC11	The Harbour View	Domestic Premises
Intake P5(P)	3.6	NC12	24 Po Shan Road	Domestic Premises
Intake PFLR1(P)	3.7	NC13	Honey Court	Domestic Premises
Intake RR1(P)	3.8	NC14	Ying Wa Girl’s School	School
Intake RR1(P)	3.8	NC15	Peaksville Court	Domestic Premises
Intake THR2(P)	3.9	NC16	Hong Kong Japanese School	School
Intake W0(P)	3.12	NC17	Sir Ellis Kadoorie Secondary School	School
Intake W5(P)	3.13	NC18	Raimondi College	School
Intake W8	3.14	NC19	Hong Kong Institute of Technology	School
Intake W8	3.14	NC20	Blk A, 80 Robinson Road	Domestic Premises
Intake W12(P)	3.15	NC21	92A-92C Sylvanbrook	Domestic Premises

3.3.2 When alternative monitoring locations are proposed, the monitoring locations should be chosen based on the following criteria:-

(a) at locations close to the major site activities which are likely to have noise impacts;

(b) close to the noise sensitive receivers. For the purposes of this section, any domestic premises, hotel, hostel, temporary housing accommodation, hospital, medical clinic, educational institution, place of public worship, library, court of law, performing art centre should be considered as noise sensitive receiver; and

(c) for monitoring locations located in the vicinity of the sensitive receivers, care should be taken to cause minimal disturbance to the occupants during monitoring.

3.3.3 The monitoring station shall normally be at a point 1m from the exterior of the sensitive receivers building facade and be at a position 1.2m above the ground. If there is problem with access to the normal monitoring position, an alternative position may be chosen, and a correction to the measurements shall be made. For reference, a correction of +3dB(A) shall be made to the free field measurements. The ET Leader shall agree with the IEC on the monitoring position and the corrections adopted. Once the positions for the monitoring stations are chosen, the baseline monitoring and the impact monitoring shall be carried out at the same positions.

3.4 Baseline Monitoring

3.4.1 The ET Leader shall carry out baseline monitoring prior to the commencement of the construction works. The baseline monitoring shall be carried out daily for a period of at least 14 consecutive days. A schedule on the baseline monitoring for construction noise prior to the commencement of the construction works shall be submitted to the ER for approval and IEC agreement before the monitoring starts.

3.4.2 Before commencing the baseline monitoring, the ET leader shall inform the IEC of the baseline monitoring programme such that the IEC can conduct on-site audit to ensure accuracy of the baseline monitoring results.

3.4.3 There shall not be any construction activities in the vicinity during the baseline monitoring. In exceptional cases, when insufficient baseline monitoring data or questionable results are obtained, the ET Leader shall liaise with IEC to agree on an appropriate set of data to be used as a baseline reference.

3.4.4 Noise monitoring shall be carried out at all the designated monitoring stations. The monitoring frequency shall depend on the scale of the construction activities. The following is an initial guide on the regular monitoring frequency for each station on a per week basis when noise generating activities are underway:-

(a) one set of measurements between 0700-1900 hours on normal weekdays;

(b) one set of measurements between 1900-2300 hours;

(d) one set of measurements between 0700-1900 hours on holidays.

3.4.5 For the measurements (b), (c) and (d) above, one set of measurements shall at least include 3 consecutive Leq (5 min) results.

3.5 Impact Monitoring

3.5.1 Noise monitoring shall be carried out at all the designated monitoring stations. The monitoring frequency shall depend on the scale of the construction activities. The following is an initial guide on the regular monitoring frequency for each station once every week in accordance with the methodology in the TM when noise generating activities are underway:-

· one set of measurements between 0700-1900 hours on normal weekdays;

3.5.2 If a school exists near the construction activity, noise monitoring shall be carried out at the monitoring stations for the school during the school examination periods. The ET Leader shall liaise with the school's personnel and the Examination Authority to ascertain the exact dates and times of all examination periods during the course of the construction.

3.5.3 In case of non-compliance with the construction noise criteria, more frequent monitoring as specified in the Event/Action Plan in Section 3.6 of this Manual shall be carried out. This additional monitoring shall be continued until the recorded noise levels are rectified or proved to be irrelevant to the construction activities.

3.6 Event and Action Plan for Construction Noise

3.6.1 The Action and Limit levels for construction noise are defined in Table 3.2. Should non-compliance of the criteria occur, action in accordance with the Event/Action Plan in Table 3.3, shall be carried out. As residual impacts are predicted at some NSRs according to the air borne noise construction noise assessment presented in the EIA report, the Event/Action Plan and the construction stage noise EM&A work shall be strictly implemented to facilitate identification of practicable measures to minimize the residual noise impacts.

Table 3.2 Action and Limit Levels for Construction Noise

Time Period	Action	Limit
0700-1900 hrs on normal weekdays	When one documented complaint is received	75* dB(A)
0700-2300 hrs on holidays; and 1900-2300 hrs on all other days		60/65/70** dB(A)
2300-0700 hrs of next day		45/50/55** dB(A)

* reduce to 70 dB(A) for schools and 65 dB(A) during school examination periods.

** to be selected based on Area Sensitivity Rating.

3.7 Residual Impact

Public Relationship Strategy

3.7.1 Having a good public relation with the local communities during the construction stage of the works is indispensable for smooth implementation of the Project. Prior to commencement of the construction, visits to the possibly affected local communities including the District Councils, nearby residents, schools and property owners will be carried out. The purpose of the visits is to advise the public the following information in relation to the Project:

· the implementation programme of the works;

· the planned construction activities that will be involved;

· the possible impacts to the affected communities;

· the measures to avoid or mitigate any adverse impacts;

· the monitoring programme to check the efficiency of the measures; and

· the communication channels between the local communities and the project office for better understanding the efficiency of the measures taken and the necessity for enhancement of the measures.

3.7.2 To maintain a better communication link with the local communities, it will specify under the contract to establish a 24-hour hot line manned by the Contractor such that all the received enquiries or complaints could be logged immediately and forwarded to the relevant project officers to follow up. Under the establishment of the project site office, liaison officers will also be nominated who are responsible for regular contacts with the local communities advising them the current progress of works, the efficiency of the environmental mitigation measures and any follow-up action that have been taken in responses to any non-compliances or complaints received from the local communities. It is considered that such a close relation between the local communities and the project site office could ensure speedy resolution of any environmental non-compliance and maintain an environmental standard acceptable to the communities during construction.

Table 3.3 Event/Action Plan for Construction Noise

EVENT	ACTION
	ET	IEC	ER	Contractor
Action Level	1. Notify IEC, ER and Contractor 2. carry our investigation by reviewing all the relevant monitoring data and the corresponding construction activities. Exceedances should also be confirmed by immediate verification in the field as far as practical. 3. Report the results of investigation to the IEC, ER and Contractor 4. Discuss with the Contractor and formulate remedial measures 5. increase monitoring frequency to check mitigation effectiveness	1.Review the analysed results submitted by the ET 2. Review the proposed remedial measures by the Contractor and advise the ER & ET accordingly 3.Supervise the implementation of remedial measures	1. Confirm receipt of notification of complaint in writing 2. Notify Contractor 3. require Contractor to proposed remedial measures for analyzed noise problem 4. Ensure remedial measures are properly implemented	1. Identify practicable measures to minimize the noise impact. Submit noise mitigation proposals to ET, IEC and ET. 2. Implement noise mitigation proposals
Limit Level	1. Notify IEC, ER, EPD and Contractor 2. Identify the source(s) of impact by reviewing all the relevant monitoring data and the corresponding construction activities. Exceedances should also be confirmed by immediate verification in the field as far as practical. 3. Repeat measurement to confirm findings 4. Increase monitoring frequency 5. Carry out analysis of Contractor’s working procedures to determine possible mitigation to be implemented. 6. inform IEC, ER and EPD the cause & actions taken for the exceedances 7. Assess effectiveness of Contractor’s remedial actions and keep IEC, EPD and ER informed of the results 8. If exceedance stops, cease additional monitoring.	1. Discuss amongst ER, ET, and Contractor on the potential remedial actions 2. Review Contractor’s remedial actions to assure their effectiveness and advise the ER &ET accordingly 3.Supervise the implementation of the remedial measures	1. Confirm receipt of notification of exceedance in writing 2. Notify Contractor 3. Require Contractor to propose remedial measures for the analyzed noise problem 4. Ensure remedial measures are properly implemented 5. If exceedance continuous, consider what portion of the work is responsible and instruct the Contractor to stop that portion of work until the exceedance is aborted	1. Take immediate action to avoid further exceedance 2. Identify practicable measures to minimize the noise impact. Submit proposals for remedial actions to ER within three working days of notification 3. Implement the agreed proposals 4. Resubmit proposal if problem still not under control 5. Stop the relevant portion of works as determined by the ER until the exceedance is abated

3.8 Ground Borne Construction Noise Monitoring

3.8.1 Based on the recommendations of the EIA study, it is required to carry out ground borne noise monitoring to ensure that proper control of groundborne noise is executed by the contractor. The monitoring frequency shall be the same as stated in Section 3.5.

3.9 Monitoring Locations for Groundborne Construction Noise

3.9.1 Prediction of construction groundborne noise indicates the criteria will be achieved at all NSRs during day-time.

3.9.2 Eight designated monitoring stations (GNC1 to GNC8) are selected for construction groundborne noise monitoring to check for compliance. Table 3.4 describes the construction groundborne noise monitoring locations, which are also depicted in Figures 2.1, 2.2 and 3.16-3.18. The status and locations of noise sensitive receivers may change after issuing this manual. If such cases exist, the ET Leader shall propose updated monitoring locations and seek approval from ER and agreement from the IEC of the proposal.

3.9.3 The monitoring locations are selected at sensitive receivers (e.g. schools or domestic premises). The Legend (GNC2) near Eastern Portal, Aegean Terrance (GNC3) near Western Portal, Carriana Sasson (CNC4) near Western Portal, Green Villa (GNC7) near the alignment of adit with vertical shaft W3 are residential buildings. True Night Middle School (GNC1), Hong Kong University Educational Institute (GNC5), French International School (GNC6) and Raimondi College (GNC8) are for educational purposed.

Table 3.4 Locations for Ground borne Construction Noise Monitoring Stations

Location	Fig. no.	Monitoring Stations	Descriptions	Status
Near Eastern Portal	2.1	GNC1	True Night Middle School	School
Near Eastern Portal	2.1	GNC2	The Legend (Future development)	Domestic Premises
Near Western Portal	2.2	GNC3	Aegean Terrace	Domestic Premises
Near Western Portal	2.2	GNC4	Carriana Sasson	Domestic Premises
Near Western Portal	2.2	GNC5	Hong Kong University Educational Institute	School
Tunnel chainage CH+ 1950	3.16	GNC6	French International School	School
Near Intake W3(P)	3.17	GNC7	Hong Villa	Domestic Premises
Near Intake W5(P)	3.18	GNC8	Raimondi College	School

3.9.4 The criterion include TM for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites (TM-Places) under the NCO stipulates that noise transmitted primarily through the structural elements of building, or buildings shall be 10dB(A) less than the relevant ANLs.

3.9.5 Table 3.5 indicates the noise criteria which apply for the groundborne noise assessment. The ground borne noise criteria during restricted hours (daytime during holidays, all evening and nighttime) presented in Tables 3.5, 3.6a and 3.6b which only refer to areas with ASR “B” for demonstration purpose. There are some factors affecting the assessment results of a CNP application, such as the assigning of Area Sensitivity Rating. As the situations/conditions around the sites may change from time to time, the Noise Control Authority would decide at the time of assessment of such an application based on the contemporary situations/conditions. Notwithstanding the above, the use of PME (including TBM) for carrying out of construction work during the restricted hours will require a CNP.

Table 3.5 Construction Ground Borne Noise Standards

	Ground Borne Noise Criteria, dB(A) (Leq, 30 mins)
Uses	Daytime (except General Holidays and Sundays)*	Daytime during general holidays and Sundays and all days during Evening (1900 to 2300 hrs)**	Night time (2300 to 0700 hrs)**
Domestic Premises	65	55	40
Educational Institutions (normal periods)	60	55	[1]
Educational Institutions (during examination periods)	55	55	[1]

* 10 dB(A) below the noise criteria stipulated in EIAO-TM

** 10 dB(A) below the noise criteria stipulated in GW-TM

[1] No sensitive uses usually present during these periods

3.9.6 If the ground borne level exceeds in the defined limit measured during TBM operation, TBM construction work and the associated works should be restricted during the all days evening / all days night-time / day time including general holidays and Sundays. Tables 3.6a and 3.6b show the follow up actions for ground borne noise monitoring if exceedance is found at representative monitoring locations. The noise level should be measured on the ground floor inside the nearest building during the TBM construction work in the evening and early morning.

Table 3.6a TBM Working Hours - Sensitive Receiver (Domestic Premise)

Scenario	Monitoring Time	Monitoring Result	Working hours of TBM or associated work operation
A	Day time	55 dB(A) < x < 65 dB(A)	Day time (Except general holidays and Sundays) (0700 – 1900 hrs) only
B^§	Day time	40 dB(A) < x < 55 dB(A)	Day time including general holidays and Sundays and all days during evening (0700-2300 hrs) only
C^§	Day time	< 40 dB (A)	No restriction

Table 3.6b TBM Working Hours - Sensitive Receiver (Education Institution)

Scenario

Monitoring Time

Monitoring Result

Working hours of TBM or associated work operation

Day time

55 dB(A) < x < 60 dB(A)

Day time (Except general holidays and Sundays) (0700 – 1900 hrs) only

E^§

Day time

x < 55 dB(A)

No restriction

Remarks:

§ - For scenarios B, C and E, they reflect the working hours are subject to CNP application.

4. water quality

4.1 Water Quality Parameters

4.1.1 An assessment of potential impacts to water quality due to the construction and operation of Drainage Improvement in Northern Hong Kong Island – Hong Kong West Drainage Tunnel has been carried out and identified in the EIA Report. The water quality assessment in the EIA identified that the key impacts may arise from the intakes and tunnel excavation works, construction of temporary berthing point, outlet structure and stilling basin at western portal. To minimise the potential impacts arising from the construction on the water quality in the vicinity of water sensitive receivers, proper construction methods with good site practices are required. The measures include installation of proper drainage system to collect site runoff and silt curtain in the waters around the temporary berthing point to prevent dispersion of suspended particle. Groundwater level monitoring would also be carried out at those construction works areas near to the natural streams during the first year of operation phase (maintenance period) to assess effect of tunnel construction to the existing ground water regime.

4.1.2 Water quality monitoring and audit for the project are required to ensure compliance with the water quality criteria and the effectiveness of the proposed mitigation measures. Marine water quality monitoring and audit shall be carried out during the construction period for the works at the Western Portal. The related construction activities includes construction of temporary berthing facility, outlet structure, stilling basin, tunnel boring at western portal. If proper measures are not taken, it may have short term impacts on the marine water quality.

4.1.3 It was considered that site inspections should also be required to ensure that the recommended water pollution mitigation measures would be properly implemented, functioned and maintained during construction phase of the DP. The requirements of site inspections are detailed in Section 10.

4.2 Water Quality Parameters

4.2.1 The following water quality parameters will be included in the monitoring programme during construction phase.

Table 4.1 Water Quality Parameters

Phase

Water Quality Parameters

Construction

· Temperature (°C)

· pH (pH unit)

· turbidity (NTU)

· water depth (m)

· salinity (mg/L)

· dissolved oxygen (DO) (mg/L and % of saturation)

· suspended solids (SS) (mg/L)

4.3 Monitoring Equipment

4.3.1 For water quality monitoring, the following equipments will be supplied by the ET and approved by the ER.

Dissolved Oxygen (DO) and Temperature Measuring Equipment

4.3.2 The instrument for measuring dissolved oxygen and temperature will be portable and weatherproof completed with cable, sensor, comprehensive operation manuals and use DC power source. It will be capable of measuring:

· a dissolved oxygen level in the range of 0-20 mg/L and 0-200% saturation; and

· a temperature of 0-45 degree Celsius.

4.3.3 It will have a membrane electrode with automatic compensation completed with a cable. Sufficient stocks of spare electrodes and cables will be available for replacement where necessary (e.g. YSI model 59 meter, YSI 5739 probe, YSI 5795A submersible stirrer with reel and cable or an approved similar instrument).

4.3.4 In situ salinity will be measured to calibrate the DO equipment prior to each DO measurement if salinity compensation is not built-in in the DO equipment.

Turbidity

4.3.5 Turbidity will be measured in situ by the nephelometric method. The instrument will be portable and weatherproof using a DC power source complete with cable, sensor and comprehensive operation manuals. The equipment will be capable of measuring turbidity between 0-1000 NTU. The probe cable will not be less than 25m in length. The meter will be calibrated in order to establish the relationship between NTU units and the levels of SS.

Suspended Solids (SS)

4.3.6 A water sampler, consisting of a transparent PVC or glass cylinder of a capacity of not less that two litres which can be effectively sealed with cups at both ends will be used (Kahlsico Water Sampler 13SWB203 or an approved similar instrument). The water sampler will have a positive latching system to keep it open and prevent premature closure until released by a messenger when the sampler is the selected water depth.

4.3.7 Water samples for SS will be collected in high density polythene bottles, packed in ice and delivered to HOKLAS accredited laboratory for analysis as soon as possible after collection.

Water Depth Detector

4.3.8 A portable, battery-operated echo sounder (Seafarer 700 or a similar approved instrument) will be used for the determination of water depth at each designated monitoring station. This unit can either be hand held or affixed to the underside of the survey boat, if the same vessel is to be used throughout the monitoring programme.

Salinity

4.3.9 A portable salinometer capable of recording within the range of 0-40 ppt will be used for salinity measurements.

Water Sampling for Laboratory Analysis

4.3.10 A water sampler as detailed in Section 4.3.6 will be used to collect samples for laboratory analysis.

Position System

4.3.11 A portable salinometer capable of recording within the range of 0-40 ppt will be used for salinity measurements.

4.3.12 A hand held or boat fixed type Digital Global Positioning System (DGPS) will be used to ensure that the correction location has been selected prior to sample collection. Coordinates checking should be carried out with a DGPS. The DGPS should be calibrated at appropriate checkpoint (e.g. Quarry Bay Survey Nail at Easting 840683.49, Northing 816709.55) to ensure the monitoring station is at the correct position before taking measurement and water samples.

Sample Container and Storage

4.3.13 Following collection, water samples for SS analysis will be stored in high density polythene bottles with no preservative added, packed in ice (cooled to 4°C without being frozen), delivered to the laboratory and analysed as soon as possible.

Calibration of In Situ Instruments

4.3.14 All in situ monitoring instruments will be 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 water quality monitoring.

4.3.15 For the on site calibration of field equipment, the BS 1427:1993, "Guide to Field and on-site test methods for the analysis of waters" will be observed.

4.3.16 Sufficient stocks of spare parts will be maintained for replacements when necessary. Backup monitoring equipment will also be made available so that monitoring can proceed uninterrupted even when some equipment is under maintenance, calibration, etc.

Laboratory Analytical Methods

4.3.17 Analysis of SS will be carried out in a HOKLAS or other international accredited laboratory. The following table shows the standard test methods of the proposed determinants for laboratory analysis.

Table 4.2 Methods for Laboratory Analysis for Water Samples

Parameters (Unit)	Suggested Method	Detection Limit
SS (mg/L)	APHA 2540 D	< 0.1 mg/L

Notes:

APHA= American Public Health Association: Standard Methods for the Examination of Water and Wastewater Ed 19

4.3.18 The testing laboratory will be HOKLAS accredited (or if not, approved by the ER) and comprehensive quality assurance and control procedures in place in order to ensure quality and consistency in results.

4.3.19 If a site laboratory is set up or a non-HOKLAS and non-international accredited laboratory is hired for carrying out the laboratory analysis, the laboratory equipment, analytical procedures, and quality control will be approved by ER. All the analysis will be witnessed by the ER.

4.3.20 The ET will provide the ER with one copy of the relevant chapters of the "Standard Methods for the Examination of Water and Wastewater" updated edition and any other relevant document for his reference.

4.3.21 For the testing methods of other parameters as recommended by EPD, detailed testing methods, pre-treatment procedures, instrument use, quality assurance/quality control (QA/QC) details (such as blank, spike recovery, number of duplicate samples per batch, etc.), detection limits and accuracy will be submitted to EPD for approval prior to the commencement of monitoring programme. The QA/QC will be in accordance with the requirement of HOKLAS or international accredited scheme. The QA/QC results will be reported. EPD may also request the laboratory to carry out analysis of know standards provided by EPD for quality assurance. Additional duplicate samples may be required by EPD for inter laboratory calibration. Remaining samples after analysis will be kept by the laboratory for 3 months in case repeat analysis is required. If in-house or nonstandard methods are proposed, details of the method verification may also be required for submission to EPD. In any circumstance, the sample testing will have comprehensive quality assurance and quality control programmes. The laboratory will prepare to demonstrate the programmes to EPD.

4.4 Monitoring Locations

4.4.1 The marine water quality monitoring locations are shown in Figure 4.1 and ground water level (borehole with piezometer) monitoring locations are shown in Figures 2.1, 3.7, 3.9, 3.10, 3.11 and 3.15. Prior to the commencement of the EM&A programme, the ET leader shall agree with ER and EPD the locations of the monitoring stations. As no intake and dropshaft structures are within Country Parks, no underground water level within Country Parks are required.

Table 4.3 Methods for Laboratory Analysis for Water Samples

Monitoring station	Fig. no.	Description	Easting	Northing	Monitoring Parameters
Underground water
UC1	2.1	Eastern Portal	(i)	(i)	Underground water level is the monitoring parameter to be measured at each ground water monitoring stations. Marine water quality parameters to be monitored include temperature, pH, turbidity, water depth, salinity, dissolved oxygen (DO) and suspended solids (SS).
UC2	3.7	PFLR1(P)	(i)	(i)
UC3	3.9	THR2(P)	(i)	(i)
UC4	3.10	TP5(P)	(i)	(i)
UC5	3.11	TP789(P)	(i)	(i)
UC6	3.15	W12(P)	(i)	(i)
Marine Water
CE	4.1	Control station (Ebb)	830026	814956
CF	4.1	Control station (Flood)	831778	812420
I1	4.1	Impact Station	831088	813654
I2	4.1	Impact Station	831105	813582
Intake A	4.1	Impact Station (Cyberport intake)	831603	813044
Intake B	4.1	Impact Station (Queen Mary Hospital/Sha Wan Drive intake)	830606	814583

Note : (i) The location of ground water monitoring stations shall be determined on site to suit the actual conditions

4.4.2 The final locations and number of the monitoring points shall be agreed with EPD at least 2 weeks before undertaking any works. The status and locations of water quality sensitive receivers may change after issuing this manual. If such cases exist, the ET leader shall propose updated monitoring locations and seek approval from the IEC and DEP.

4.4.3 When alternative monitoring locations are proposed, they shall be chosen based on the following criteria:

(a) at locations close to and preferably at the boundary of the mixing zone of the major site activities as indicated in the EIA final report, which are likely to have water quality impacts;

(b) close to the sensitive receptors which are directly or likely to be affected;

(c) for monitoring locations located in the vicinity of the sensitive receptors, care shall be taken to cause minimal disturbance during monitoring;

4.4.4 Control stations are necessary to compare the water quality from potentially impacted sites with the ambient water quality. Control stations shall be located within the same body of water as the impact monitoring stations but shall be outside the area of influence of the works and, as far as practicable, not affected by any other works. For underground water monitoring, the measured ground water levels should be compared with the pre-construction monitoring data carried out by the project office.

4.4.5 Replicates in-situ measurements and sample (except ground water monitoring) collected from each independent sampling event are required for all parameters to ensure a robust statistically interpretable dataset.

4.5 Baseline Monitoring

Marine Water

4.5.1 Baseline conditions for water quality will be established and agreed upon with ER and EPD prior to the commencement of works. The purpose of the baseline monitoring is to establish ambient conditions prior to the commencement of the works and to demonstrate the suitability of the proposed impact, control and reference monitoring stations.

4.5.2 The baseline conditions will normally be established by measuring all the water quality parameters for the construction phase monitoring as illustrated in Figure 4.1. The measurements will be taken at all designated monitoring stations 3 days per week, at mid-flood and mid-ebb tides, at three depth locations (i.e. 1 m below surface, mid-depth and 1m from bed), for a period of 4 weeks prior to the commencement of marine works. The interval between two sets of monitoring will not be less than 36 hours and the baseline monitoring schedule will be submitted to ER and EPD at least 2 week prior to the commencement of the baseline monitoring. Flow rates and sample depth will be also recorded, where appropriate. Also, all seasonal variations such as rainfall, tidal flow, typhoons and shipping activities will be assessed. For the selection of tide for water quality monitoring, tidal range of less than 0.5m should be avoided for both flood and ebb tides.

4.5.3 Measurements will be taken at 3 water depths, namely, 1m below water surface, mid-depth and 1m above sea bed, except where the water depth less than 6 m, the mid-depth station may be omitted.