1. BACKGROUND

1.1 An application (No. ESB-081/2001) for an Environmental Impact Assessment (EIA) study brief under section 5(1) of the Environmental Impact Assessment Ordinance (EIAO) was submitted by the Applicant on 26 July 2001 with a project profile (No. PP-137/2001) (the Project Profile).

1.2 The Applicant proposes to construct the Hong Kong portion of a dual-3 lane highway, named as Shenzhen Western Corridor (SWC) (the Project), across Deep Bay to link up Shekou in the Mainland with the northwestern territory of the Hong Kong Special Administrative Region (HKSAR), as shown in Appendix A and described below :-

(a) The highway will be constructed tentatively on bridge structure. The section of the highway within the HKSAR waters, about 3km in length, will be constructed under this Project. Other structural forms of the highway will be reviewed and investigated.

(b) At the northern end, the proposed highway will be connected to the section of the road at the Shenzhen/HKSAR boundary to be constructed by the Mainland authorities (the Mainland Section). The landing location in Shenzhen will be located at Dongjiatou.

(c) At the southern end, the proposed highway will be connected to the future Deep Bay Link (DBL) in the HKSAR.

(d) Two possible landing locations, one at Ngau Hom Skek and another at Ngau Hom Sha, are being investigated under the DBL project for connection by the SWC. These landing locations are shown in Appendix A.

(e) Whereas almost all the permanent works will be located offshore, certain activities will have to be carried out on land in the works areas and along the access roads.

1.3 Pursuant to section 5(7)(a) of the EIAO, the Director of Environmental Protection (the Director) issues this EIA study brief to the Applicant to carry out an EIA study.

1.4 The purpose of this EIA study is to provide information on the nature and extent of environmental impacts arising from the construction and operation of the Project and related activities that take place concurrently. This information will contribute to decisions by the Director on :

(i) the overall acceptability of any adverse environmental consequences that are likely to arise as a result of the Project;

(ii) the conditions and requirements for the detailed design, construction and operation of the Project to mitigate against adverse environmental consequences wherever practicable; and

(iii) the acceptability of residual impacts after the proposed mitigation measures are implemented.

2. OBJECTIVES OF THE EIA STUDY

2.1 The objectives of the EIA study are as follows :

(i) to describe the Project and associated works together with the requirements for carrying out the Project;

(ii) to identify and describe elements of community and environment likely to be affected by the Project and/or likely to cause adverse impacts to the Project, including natural and man-made environment and the associated environmental constraints;

(iii) to consider alternatives with a view to avoiding and minimizing the potential environmental impacts to the ecological sensitivity areas in Deep Bay and other sensitive uses; to compare the environmental benefits and dis-benefits of each of the different options; to provide reasons for selecting the preferred option(s) and to describe the part of environmental factors played in the selection;

(iv) to identify and quantify emission sources and determine the significance of impacts on sensitive receivers and potential affected uses;

(v) to identify and quantify any potential landscape and visual impacts and to propose measures to mitigate these impacts;

(vi) to identify and quantify any potential losses or damage to flora, fauna and natural habitats and to propose measures to mitigated these impacts;

(vii) to identify any negative impacts on site of cultural heritage and to propose measures to mitigate these impacts;

(viii) to propose the provision of mitigation measures so as to minimize pollution, environmental disturbance and nuisance during construction and operation of the Project;

(ix) to investigate the feasibility, practicability, effectiveness and implications of the proposed mitigation measures;

(x) to identify, predict and evaluate the residual environmental impacts (i.e. after practicable mitigation) and the cumulative effects expected to arise during the construction and operation phases of the Project in relation to the sensitive receivers and potential affected uses;

(xi) to identify, assess and specify methods, measures and standards, to be included in the detailed design, construction and operation of the Project which are necessary to mitigate these environmental impacts and cumulative effects and reduce them to acceptable levels;

(xii) to investigate the extent of the secondary environmental impacts that may arise from the proposed mitigation measures and to identify constraints associated with the mitigation measures recommended in the EIA study, as well as the provision of any necessary modification; and

(xiii) to design and specify environmental monitoring and audit requirements to ensure the effective implementation of the recommended environmental protection and pollution control measures.

3. DETAILED REQUIREMENTS OF THE EIA STUDY

3.1 The Purpose

The purpose of this study brief is to scope the key issues of the EIA study. The Applicant has to demonstrate in the EIA report that the criteria in the relevant sections of the Technical Memorandum on the Environmental Impact Assessment Process of the Environmental Impact Assessment Ordinance (hereinafter referred to as "the TM") are fully complied with.

3.2 The Scope

The scope of this EIA study shall cover the Project mentioned in Section 1.2 above. The EIA study shall address the likely key issues described below, together with any other key issues identified during the course of the EIA study :

(i) the potential impacts to the ecological sensitive areas in Deep Bay including the Mai Po and Inner Deep Bay Ramsar Site;

(ii) the potential aquatic and terrestrial ecological impacts arising from the construction works, including loss of habitats, removal of mangroves and vegetation, and disturbance to birds and animals;

(iii) the potential impacts on the local erosion and sedimentation patterns in Deep Bay, including the mudflats in Deep Bay, during the construction and operation of the Project;

(iv) the potential water quality impact caused by dredging activities during construction and as a result of changes to the flow regime and flushing capacity in Deep Bay during operation of the Project;

(v) the potential noise and air pollution impacts to sensitive receivers during the construction and operation of the Project;

(vi) the cumulative environmental impacts of the Project, through interaction or in combination with other existing, committed and planned developments in the vicinity of the Project, and that those impacts may have a bearing on the environmental acceptability of the Project. Consideration shall be given to account for the impacts from likely concurrent projects such as the Deep Bay Link and the Mainland Section of the SWC;

(vii) the potential visual impact caused by the highway structure, if it is in bridge-form; and

(viii) the potential impacts on sites of cultural heritage likely to be affected by the construction works, in particular, at the Ngau Hom Shek Archaeological Site.

3.3 Consideration of Alternative Alignment Options and Construction Methods

3.3.1 Consideration of Different Alignment Options and Built-forms

In addition to the proposed alignment options mentioned in Section 1.2 above, the Applicant shall consider other feasible alignment options for the Project, taking on board the findings of those options already addressed in previous studies such as the Stage 2 Feasibility Study for Additional Cross-border Link. Alternative built-form (such as tunnel) and design of the highway shall also be reviewed and investigated. A comparison of the environmental benefits and dis-benefits of possible alignment options and alternative built-forms and design shall be made with a view to recommending the preferred option to avoid adverse environmental effects in Deep Bay to the maximum practicable extent. In particular, consideration shall be given to avoid or minimize the disturbance to the inter-tidal zone and mudflats along the Deep Bay coastline.

3.3.2 Consideration of Alternative Construction Methods and Sequences of Works

Taking into consideration the combined effect with respect to the severity and duration of the construction impacts to the affected sensitive receivers, the EIA study shall explore alternative construction methods and sequences of works for the Project, with a view to avoid prolonged adverse environmental impacts to the maximum practicable extent. A comparison of the environmental benefits and dis-benefits of applying different construction methods and sequence of works shall be made.

3.3.3 Selection of Preferred Scenario

Taking into consideration of the findings in Sections 3.3.1 and 3.3.2 above, the Applicant shall recommend/justify the adoption of the preferred alignment and design that will avoid or minimize adverse environmental effects arising from the Project, in particular on the ecology and water quality in Deep Bay.

3.4 Technical Requirements

The Applicant shall conduct the EIA study to address all environmental aspects as described in Sections 3.1, 3.2 and 3.3 above. The EIA study shall include the following technical requirements on specific impacts.

3.4.1 Air Quality Impact

3.4.1.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing air quality impact as stated in section 1 of Annex 4 and Annex 12 of the TM, respectively.

3.4.1.2 The study area for air quality impact assessment shall generally be defined by a distance of 500 metres from the boundary of the project site, yet it shall be extended to include major emission sources that may have a bearing on the environmental acceptability of the Project. Such assessment shall be based on the best available information at the time of the assessment. In particular, the assessment shall take into account the impacts of major emission sources from the Mainland such as the Ma Wan Power Stations in the Shekou area. Reference shall be made to appropriate monitoring data or published reports such as the EIA Report on Shenzhen Ma Wan Power Station.

3.4.1.3 The Applicant shall assess the air pollutant concentrations with reference to the relevant sections of the guidelines in Appendices B-1 to B-3, or other methodology as agreed by the Director.

3.4.1.4 The air quality impact assessment shall include the following:

(i) Background and Analysis of Activities

(a) Provide background information relating to air quality issues relevant to the Project, e.g. description of the types of activities of the Project that may affect air quality during both construction and operation stages.

(b) Give an account, where appropriate, of the consideration/measures that had been taken into consideration in the planning of the Project to abate the air pollution impact. That is, the Applicant shall consider alternative construction methods/phasing programmes and alternative modes of operation to minimize the constructional and operational air quality impact respectively.

(c) Present the background air quality levels in the assessment area for the purpose of evaluating the cumulative constructional and operational air quality impacts.

(ii) Identification of Air Sensitive Receivers (ASRs) and Examination of Emission/Dispersion Characteristics

(a) Identify and describe existing and planned/committed ASRs that would likely be affected by the Project, including those earmarked on the relevant Outline Zoning Plans, Development Permission Area Plans, Outline Development Plans and Layout Plans. The Applicant shall select the assessment points of the identified ASRs that represent the worst impact point of these ASRs. A map showing the location and description such as name of building, use and height of the selected assessment points shall be given. The separation distances of these ASRs from the nearest emission sources shall also be given. For phased development, the Applicant shall review the development programme against the different construction stages to assess whether the occupiers of the early phases could become ASRs to be affected by the construction works of later phases.

(b) Provide an exhaustive list of air pollutant emission sources, including any nearby emission sources which are likely to have impact related to the Project based on the analysis of the constructional and operational activities in (i) above. Examples of construction stage emission sources include stock piling, blasting, concrete batching, marine construction plant and vehicular movements on unpaved haul roads on site, etc. Examples of operational stage emission sources include exhaust emissions from vehicles, vent shafts, etc. Confirmation of the validity of the assumptions and the magnitude of the activities (e.g. volume of construction material handled, traffic mix and volume on a road etc.) shall be obtained from the relevant government departments/authorities and documented.

(iii) Construction Phase Air Quality Impact

(a) The Applicant shall follow the requirements stipulated under the Air Pollution Control (Construction Dust) Regulation to ensure that construction dust impacts are controlled within the relevant standards as stipulated in section 1 of Annex 4 of the TM. A monitoring and audit programme for the construction phase shall be devised to verify the effectiveness of the control measures proposed so as to ensure proper construction dust control.

(b) If the Applicant anticipates that the Project will give rise to significant construction dust impacts likely to exceed the recommended limits in the TM at the ASRs despite the incorporation of the dust control measures proposed in accordance with sub-section 3.4.1.4(iii)(a) above, a quantitative assessment should be carried out to evaluate the construction dust impact at the identified ASRs. The Applicant shall follow the methodology set out in sub-section 3.4.1.4(v) below when carrying out the quantitative assessment.

(iv) Operational Phase Air Quality Impact

(a) The Applicant shall calculate the expected air pollutant concentrations at the identified ASRs based on an assumed reasonably worst case scenario. The evaluation shall be based on the strength of the emission sources identified in sub-section 3.4.1.4(ii)(b) above. The Applicant shall follow sub-section 3.4.1.4(v) below when carrying out the quantitative assessment.

(b) For calculation of future road traffic air pollution impacts, this shall be based on the highest emission strength from the road within the next 15 years upon commencement of operation of the proposed road. The Applicant shall demonstrate that the selected year of assessment represents the highest emission scenario given the combination of vehicular emission factors and traffic flow for the selected year.

(c) If vehicular tunnels and/or full enclosures are proposed in the project, it is the responsibility of the Consultants to ensure that the air quality inside these proposed structures shall comply with EPD's "Practice Note on Control of Air Pollution in Vehicle Tunnels". For assessment of air quality impact due to emissions from tunnels/full enclosures, the Applicant shall ensure that the emission amount and the pollutants emitted from these tunnel/full enclosures have been agreed with the relevant tunnel ventilation design engineer and documented.

(v) Quantitative Assessment Methodology

(a) The Applicant shall apply the general principles enunciated in the modeling guidelines in Appendices B1 to B3 while making allowance for the specific characteristic of the Project. This specific methodology must be documented in such level of details (preferably with tables and diagrams) to allow the readers of the assessment report to grasp how the model is set up to simulate the situation at hand without referring to the model input files. Details of the calculation of the emission rates of air pollutants for input to the modeling shall be presented in the report. The Applicant must ensure consistency between the text description and the model files at every stage of submission. In case of doubt, prior agreement between the Applicant and the Director on the specific modelling details should be sought.

(b) The Applicant shall identify the key/representative air pollutant parameters (types of pollutants and the averaging time concentration) to be evaluated and provide explanation for choosing these parameters for the assessment of the impact of the Project.

(c) The Applicant shall calculate the cumulative air quality impact at the identified ASRs and compare these results against the criteria set out in section 1 of Annex 4 in the TM. The predicted air quality impacts (both unmitigated and mitigated) shall be presented in the form of summary table and pollution contours, to be evaluated against the relevant air quality standards and on any effect they may have on the land use implications. Plans of a suitable scale should be used to present pollution contour to allow buffer distance requirements to be determined properly.

(d) If there are any direct technical noise remedies recommended in the study, the air quality implication due to these technical remedies shall be assessed. For instance, if barriers that may affect dispersion of air pollutants are proposed, then the implications of such remedies on air quality impact shall be assessed. If tunnel or noise enclosure is proposed, then portal emissions of the tunnel/enclosed road section and air quality inside the enclosed road section shall also be addressed. The Applicant shall highlight clearly the locations and types of agreed noise mitigating measures, ASR's as well as tunnel/road enclosure and their portals (where applicable) on the contour maps for easy reference.

(vi) Mitigation Measures for Non-compliance

The Applicant shall propose remedies and mitigating measures where the predicted air quality impact exceeds the criteria set in section 1 of Annex 4 in the TM. These measures and any constraints on future land use planning shall be agreed with the relevant government departments/authorities and documented. The Applicant shall demonstrate quantitatively that the resultant impacts after incorporation of the proposed mitigating measures will comply with the criteria stipulated in section 1 of Annex 4 in the TM.

(vii) Submission of Model Files

All input and output file(s) of the model run(s) shall be submitted to the Director in electronic format.

3.4.2 Noise Impact

3.4.2.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing noise impact as stated in Annexes 5 and 13 of the TM, respectively.

3.4.2.2 The noise impact assessment shall include the following :

(i) Determination of Assessment Area

The study area for the noise impact assessment shall generally include all areas within 300m from the Project shown in Annex A of the Project Profile (No. PP-137/2001). Subject to the agreement of the Director, the assessment area could be reduced accordingly if the first layer of noise sensitive receivers (NSRs), closer than 300m from the outer project limit, provides acoustic shielding to those receivers at further distance behind. Subject to the agreement of the Director, the assessment area shall be expanded to include NSRs at larger distance which would be affected by the construction and operation of the Project.

(ii) Provision of Background Information and Existing Noise Levels

The Applicant shall provide all background information relevant to the Project, e.g. relevant previous or current studies. Unless involved in the planning standards, e.g. those for planning of fixed noise sources, no existing noise levels are particularly required.

(iii) Identification of Noise Sensitive Receivers

(a) The Applicant shall refer to Annex 13 of the TM when identifying the NSRs. The NSRs shall include all existing NSRs and all planned/committed noise sensitive developments and uses earmarked on the relevant Outline Zoning Plans, Development Permission Area Plans, Outline Development Plans and Layout Plans.

(b) The Applicant shall select assessment points to represent all identified NSRs for carrying out quantitative noise assessment described below. The assessment points shall be agreed with the Director prior to the quantitative noise assessment. A map showing the location and description such as name of building, use, and floors of each and every selected assessment point shall be given. For planned noise sensitive land uses without committed site layouts, the Applicant should use the relevant planning parameters to work out site layouts for operational noise assessment purpose.

(iv) Provision of an Emission Inventory of the Noise Sources

The Applicant shall provide an inventory of noise sources including construction equipment for construction noise assessment and fixed plant equipment, as appropriate, for operational noise assessment. Confirmation of the validity of the inventory shall be obtained from the relevant government departments/authorities and documented.

(v) Construction Noise Assessment

(a) The Applicant shall carry out assessment of noise impact from construction (excluding percussive piling) of the Project during day time, i.e. 7 a.m. to 7 p.m., on weekdays other than general holidays in accordance with the methodology stipulated in paragraphs 5.3. and 5.4 of Annex 13 of the TM. The criteria in Table 1B of Annex 5 of the TM shall be adopted in the assessment.

(b) To minimize the construction noise impact, alternative construction methods to replace percussive piling shall be proposed as far as practicable. In case blasting works will be involved, it should be carried out, as far as practicable, outside the sensitive hours of 7 p.m. to 7 a.m. on Monday to Saturday and any time on a general holiday, including Sunday. For blasting that must be carried out during the above-mentioned sensitive hours, the noise impact in associated with the removal of debris and rocks should be fully assessed and adequate mitigation measures should be recommended to reduce the noise impact as appropriate. If tunnelling works will be involved, noise impact (including air-borne noise and structure-borne noise) associated with the operation of powered mechanical equipment, in particular, tunnel boring machine or equivalent, shall be assessed.

(c) If the unmitigated construction noise levels are found exceeding the relevant criteria, the Applicant shall propose practicable direct mitigation measures (including movable barriers, enclosures, quieter alternative methods, re-scheduling and restricting hours of operation of noisy task) to minimize the impact. If the mitigated noise levels still exceed the relevant criteria, the duration of the noise exceedance shall be given.

(d) In case the Applicant would like to evaluate whether construction works in restricted hours as defined under the Noise Control Ordinance (NCO) are feasible or not in the context of programming construction works, reference should be made to the relevant technical memoranda issued under the NCO. Regardless of the results of the construction noise impact assessment for restricted hours, the Noise Control Authority will process the Construction Noise Permit (CNP) application, if necessary, based on the NCO, the relevant technical memoranda issued under the NCO, and the contemporary conditions/situations. This aspect should be explicitly stated in the noise chapter and the conclusions and recommendations chapter in the EIA report.

(vi) Operational Noise Assessment

(a) Road Traffic Noise

(a1) Calculation of Noise Levels

The Applicant shall analyse the scope of the proposed road alignment(s) to identify appropriate new and existing road sections for the purpose of traffic noise impact assessment. When an existing road section undergoes major modification which will directly result in 25% increase in lanes or substantial changes in alignment or characters (e.g. change to a high speed road) of the existing road, it shall be regarded as a new road for the purpose of this noise impact assessment.

The Applicant shall calculate the expected road traffic noise using methods described in the U.K. Department of Transport's "Calculation of Road Traffic Noise" (1988). Calculations of future road traffic noise shall be based on the peak hour traffic flow in respect of the maximum traffic projection within a 15 years period upon commencement of operation of the proposed roadwork. The Applicant shall calculate traffic noise levels in respect of each road section and the overall noise levels from combined road sections (both new and existing) at NSRs.

(a2) Presentation of Noise Levels

The Consultants shall present the existing and future noise levels in L10 (1 hour) at the NSRs on tables and plans of suitable scale.

A quantitative assessment at the NSRs for the proposed road alignments shall be carried out and compared against the criteria set out in Table 1A of Annex 5 of the TM.

(a3) Proposals for Noise Mitigation Measures

After rounding of the predicted noise levels according to the U.K. Department of Transport's "Calculation of Road Traffic Noise" (1988), the Applicant shall propose direct technical remedies in all situations where the predicted traffic noise level exceeds the criteria set in Table 1A of Annex 5 in the TM by 1 dB(A) or more. Specific reasons for not adopting certain direct technical remedies in the design to reduce the traffic noise to a level meeting the criteria in the TM or to maximize the protection for the NSRs as far as possible should be clearly quantified and laid down. The total number of dwellings, classrooms and other noise sensitive element that will be benefited by the provision of direct technical remedies should be provided.

The total number of dwellings, classrooms and other noise sensitive elements that will still be exposed to noise above the criteria with the implementation of all recommended direct technical remedies shall be quantified.

In case where a number of the NSRs cannot all be protected by the recommended direct technical remedies, the Applicant shall identify and estimate the total number of existing dwellings, classrooms and other noise sensitive elements which may qualify for indirect technical remedies under the Executive Council directive "Equitable Redress for Persons Exposed to Increased Noise Resulting from the Use of New Roads", the associated costs and any implications for such implementation. For the purpose of determining the eligibility of the affected premises for indirect technical remedies, reference shall be made to the following set of three criteria:

(1) the predicted overall noise level from the new road together with other traffic noise in the vicinity must be above a specified noise level (e.g. 70 dB(A) for domestic premises and 65 dB(A) for education institutions, all in L10(1hr));

(2) the predicted overall noise level is at least 1.0 dB(A) more than the prevailing traffic noise level, i.e. the total traffic noise level existing before the works to construct the road were commenced; and

(3) the contribution to the increase in the predicted overall noise level from the new road must be at least 1.0dB(A).

(b) Fixed Noise Sources

If the Project will cause any fixed noise sources, such as the ventilation systems of the control centre and/or road tunnel, if any, the following assessment shall be followed.

(b1) Assessment of Fixed Source Noise Levels

The Applicant shall calculate the expected noise using standard acoustics principles. Calculations for the expected noise shall be based on assumed plant inventories and utilization schedule for the worst case scenario. The Applicant shall calculate the noise levels taking into account correction of tonality, impulsiveness and intermittency in accordance with the Technical Memorandum for the Assessment of Noise from Places other than Domestic Premises, Public Places or Construction Sites.

(b2) Presentation of Noise Levels

The Applicant shall present the existing and future noise levels in Leq (30 min) at the NSRs at various representative floor levels (in m P.D.) on tables and plans of suitable scale.

A quantitative assessment at the NSRs for the proposed fixed noise source(s) shall be carried out and compared against the criteria set out in Table 1A of Annex 5 of the TM.

(b3) Proposals for Noise Mitigation Measures

The Applicant shall propose direct technical remedies within the project limits in all situations where the predicted noise level exceeds the criteria set out in Table 1A of Annex 5 of the TM to protect the affected NSRs.

(vii) Assessment of Side Effects and Constraints

The Applicant shall identify, assess and propose means to minimize any side effects and to resolve any potential constraints due to the inclusion of any recommended direct technical remedies.

(viii) Evaluation of Constraints on Planned Noise Sensitive Developments/Landuses

For planned noise sensitive uses which will still be affected even with all practicable direct technical remedies in place, the Applicant shall propose, evaluate and confirm the practicality of additional measures within the planned noise sensitive uses and shall make recommendations on how these noise sensitive uses will be designed for the information of relevant parties.

The Applicant shall take into account agreed environmental requirements / constraints identified by the study to assess the development potential of concerned sites which shall be made known to the relevant parties.

3.4.3 Water Quality Impact

3.4.3.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing water pollution as stated in Annexes 6 and 14 of the TM respectively.

3.4.3.2 The study area for this water quality assessment shall cover the Deep Bay Water Control Zones as designated under the Water Pollution Control Ordinance (WPCO). This study area could be extended to include other areas such as stream courses and the associated water system in the Deep Bay catchment if they are found also being impacted during the course of the EIA study and have a bearing on the environmental acceptability of the Project.

3.4.3.3 The Applicant shall identify and analyze all physical, chemical and biological disruptions of marine, fresh water or ground water system(s), catchment area(s), stormwater pipeline and coastal water arising from the construction and operation of the Project.

3.4.3.4 The Applicant shall predict, quantify and assess any water quality impacts arising from the Project on the water system(s) and the sensitive receivers by appropriate mathematical modelling and/or other techniques approved by the Director. The mathematical modelling requirements are set out in Appendix C to this study brief. Possible impacts shall include but not be limited to changes in hydrology, flow regime, sediment erosion and deposition pattern, water and sediment quality, downstream salinity profile and effects on the flora and fauna due to such changes in Deep Bay.

3.4.3.5 The Applicant shall take into account and include likely different construction stages or sequences, and different operation stages of the Project in the assessment. The assessment shall have regard to the frequency, duration, volume and flow rate of the discharges and its pollutant and sediment loading. Reference shall be made to available information in previous studies including, but not limited to, those listed in Appendix C to this study brief. Essentially the assessment shall address the following:

(i) Collection and review of background information on the existing and planned water system(s) and their respective catchments and sensitive receivers which might be affected by the Project during construction and operation;

(ii) Characterization of water and sediment quality of the water system(s) and respective catchments and sensitive receivers which might be affected by the Project during construction and operation based on existing information or appropriate site survey and tests;

(iii) Identification and analysis of all existing and planned future activities and beneficial uses related to the water system(s) and identification of all water sensitive receivers. The Applicant shall refer to, inter alia, those developments and uses earmarked on the relevant Outline Zoning Plans, Development Permission Area Plans, Outline Development Plans and Layout Plans;

(iv) Identification of pertinent water and sediment quality objectives and establishment of other appropriate water and sediment quality criteria or standards for the water system(s) and all the sensitive receivers in (i) above. Reference shall be made to the Technical Report on Environmental Protection of Deep Bay and its Catchment, Appendix T, Hong Kong Guangdong Environmental Protection Liaison Group, December 1992 and other relevant publications newly acquired during the course of the EIA study;

(v) Review of the construction sequences and methods, and operation of the Project to identify any alteration of existing water courses, natural streams/ponds, shoreline or bathymetry, flow regimes, ground water levels and catchment types or areas;

(vi) Identification and quantification of all likely water and sediment pollution sources and loading, including point and non-point discharges to surface water runoff, through appropriate site investigation and tests, generated by the Project and discharged to the marine waters in Deep Bay and existing and planned drainage systems and water courses;

(vii) Establishment and provision of a pollution load inventory on the quantities and characteristics of all existing and likely future water pollution sources identified above. Field investigation and laboratory tests shall be conducted as appropriate to fill in any major information gaps;

(viii) Analysis on the provision and adequacy of existing and planned future wastewater treatment facilities in terms of capacity and level of treatment to reduce pollution arising from both the point and non-point discharges identified in (vi) above;

(ix) Assessment of the cumulative impacts due to other related concurrent and planned projects, activities or pollution sources along the identified water system(s) and sensitive receivers that may have a bearing on the environmental acceptability of the Project through hydraulic modelling. This shall include the potential cumulative construction and operational water quality impact arising from, inter alia, the Deep Bay Link project and the Mainland section of SWC;

(x) Assessment and evaluation of any potential water quality impacts on the identified water system(s), respective catchments and sensitive receivers due to sewage arising from the construction and operation stages. Any effluent generated will require appropriate collection, treatment and disposal to within standards and objectives and criteria established in (iv) above. Proposal of effective and practicable infrastructure upgrading or provision, water pollution prevention and mitigation measures to be implemented during the construction and operation stages so as to reduce the water quality impacts to within acceptable levels of standards. No net increase of pollution load to Deep Bay should be ensured;

(xi) Assessment and evaluation of any potential impacts as a result of stormwater and surface water runoff during construction and operation of the Project on the water system(s), respective catchments and sensitive receivers during construction stages. Establishment of a stormwater pollution control plan to reduce the water and sediment quality impacts during construction and operation to within standards, objectives and criteria established in (iv) above. The plan shall incorporate details such as locations, sizes and types of measures/installations and the best management practices. Attention shall be made to the water quality control and mitigation measures recommended in the ProPECC PN 1/94 paper on construction site drainage.

(xii) Should dredging be required, the Applicant shall evaluate and quantify the possible impacts arising from the dredging works. The Applicant shall identify clearly the nature, extent and rate of the dredging works, and the volume of sediment disturbed. Both the local and global effects on flow regime, erosion and sedimentation pattern and water quality due to the interim and ultimate alteration of shoreline and bathymetry as a result of dredging marine sediment in Deep Bay shall be assessed through undertaking a hydraulic modelling;

(xiii) Identification and quantification of all dredging, fill extraction, filling, mud/sediment transportation and disposal activities and requirements. Potential fill source and dumping ground to be involved shall also be identified. Appropriate laboratory tests such as elutriate tests (USACE) and sediment pore water (interstitial water) analyses shall be performed on the sediment samples to simulate and quantify the degree of mobilization of various contaminants such as metals, ammonia, trace organic contaminants such as PCBs, PAHs, TBT and chlorinated pesticides into the water column during dredging. Field investigation, sampling and chemical and biological laboratory tests to characterize the sediment/mud concerned shall be conducted as appropriate. The ranges of parameters to be analyzed; the number, type and methods of sampling; sample preservation; and chemical and biological laboratory test methods to be used shall be subject to the approval of the Director. The categories of sediments which require different types of disposal in accordance with the Works Bureau Technical Circular No. 3/2000 shall be identified by both chemical and biological tests and their quantities shall be estimated. If the presence of any seriously contaminated sediment which requires Type 3 disposal is confirmed, the Applicant shall identify the most appropriate treatment and/or disposal arrangement and demonstrate its feasibility;

(xiv) Identification and evaluation of the best practicable dredging methods to minimize dredging and dumping requirements and demand for fill sources based on the criterion that existing marine mud shall be left in place and not to be disturbed as far as possible;

(xv) In case of small scale dredging works and with the prior written approval by the Director, the Applicant shall assess the potential increase in turbidity and suspended solids levels in the water column due to disturbance of marine sediments during dredging. The potential for release of contaminants during dredging shall also be addressed using the chemical and biological testing results derived from sediment samples collected on site and relevant historic data;

(xvi) The water quality assessment shall include an assessment of the inter-relation between tidal hydraulics, the bridge configuration and the flushing capacity with a view to mitigate the pollution problems experienced in Deep Bay as a result of any reduced flushing caused by the bridge and other associated structures;

(xvii) The Applicant shall devise mitigation measures to avoid or minimize the impacts identified above. The residual impacts on the water system(s) and the sensitive receivers with regard to the relevant water quality objectives, criteria, standards or guidelines shall be assessed and quantified using appropriate mathematical models set out in Appendix C to this study brief.

3.4.4 Waste Management Implications

3.4.4.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing waste management implications as stated in Annexes 7 and 15 of the TM respectively.

3.4.4.2 The assessment of waste management implications shall cover the following:

(i) Analysis of Activities and Waste Generation

The Applicant shall identify the quantity, quality and timing of the waste arising as a result of the construction and operation activities of the Project, based on the sequence and duration of these activities.

(ii) Proposal for Waste Management

(a) Prior to considering the disposal options for various types of wastes, opportunities for reducing waste generation, on-site or off-site re-use and recycling shall be fully evaluated. Measures which can be taken in the planning and design stages e.g. by modifying the design approach and in the construction stage for maximizing waste reduction shall be separately considered.

(b) After considering all the opportunities for reducing waste generation and maximizing re-use, the types and quantities of the wastes required to be disposed of as a consequence shall be estimated and the disposal options for each type of waste shall be described in detail. Pretreatment processes for slurry before disposal shall be addressed in details. The disposal method recommended for each type of waste shall take into account of the result of the assessment in (c) below.

(c) The impact caused by handling (including labeling, packaging & storage), collection, and disposal of wastes shall be addressed in detail and appropriate mitigation measures shall be proposed. This assessment shall cover the following areas :

- potential hazard;
- air and odour emissions;
- noise;
- wastewater discharge; and
- public transport.

3.4.5 Ecological Impact (Both Terrestrial and Aquatic)

3.4.5.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing ecological impact as stated in Annexes 8 and 16 of the TM respectively.

3.4.5.2 The assessment area for the purpose of terrestrial ecological assessment shall include all areas within 500 metres from the site boundary of the land based works areas or the area likely to be impacted by the Project. For aquatic ecology, the assessment area shall be the same as the water quality impact assessment or the area likely to be impacted by the Project.

3.4.5.3 In the ecological impact assessment, the Applicant shall examine the flora, fauna and other components of the ecological habitats within the assessment area. The aim shall be to protect, maintain or rehabilitate the natural environment. In particular, the Project shall avoid impacts on recognized sites of conservation importance (e.g. Sites of Special Scientific Interest - SSSI) and other ecological sensitive areas (e.g. mangrove, mud flat). The assessment shall identify and quantify as far as possible the potential ecological impacts associated with the Project.

3.4.5.4 The assessment shall include the following major tasks:

(i) review and incorporate the findings of relevant studies including the on-going EIA study of the Deep Bay Link and the Stage 2 Feasibility Study for Additional Cross-border Links completed in 2000, and collate all the available information regarding the ecological characters of the assessment area (12 months ecology survey covering a full-year seasonal variation have been undertaken in 1998/99 under the Stage 2 Feasibility Study for Additional Cross-border Links);

(ii) evaluate the information collected from sub-sections (i) above and (iii) below, and identify any information gap relating to the assessment of potential ecological impacts to the aquatic and terrestrial environment; and determine whether another full-year seasonal ecological survey shall be required to bridge any information gap or update the information to ensure that a comprehensive ecological profile can be established as required under the following sub-section 3.4.5.4(v);

(iii) carry out necessary field surveys as determined under sub-section 3.4.5.4(ii) above, the duration of which shall be at least 6 months and cover both the wet and dry seasons, and investigations to verify the information collected, fill the information gaps identified, in terms of seasonal patterns and spatial distributions of ecological components as well as other ecological characteristics, and fulfill the objectives of the EIA study;

(iv) present all relevant survey findings including previous surveys conducted in the Feasibility for Additional Cross-border Links, Stage 2 and other relevant studies together with surveys carried out under this study;

(v) establish a comprehensive ecological profile of the study area based on data of previous studies and results of additional field surveys, and taking into consideration the variations across four seasons, and describe the characteristics of each habitat found; major information to be provided shall include:

(a) description of the physical environment;

(b) habitats maps of suitable scale showing the types and locations of habitats in the study area;

(c) ecological characteristics of each habitat type such as size, species present, dominant species found, species diversity and abundance, community structure seasonality, inter-dependence of the habitats and species, and presence of any features of ecological importance;

(d) representative colour photographs of each habitat type and any important ecological features identified;

(e) species found that are rare, endangered and/or listed under local legislation, international conventions for conservation of wildlife/habitats or red data books;

(vi) investigate and describe the existing wildlife uses of the various habitats with special attention to those wildlife groups and habitats with conservation interests, including but not limited to the following:

(a) inter-tidal mudflat

(b) mangrove

(c) seagrass bed

(d) avifauna, in particular, Black-faced Spoonbill (Platalea minor)

(e) egretries

(f) inter-tidal and sub-tidal benthic faunal communities

(g) Chinese White Dolphin (Sousa chinensis)

(h) Horseshoe crabs

(i) any other habitats and wildlife groups identified as having special conservation interests by this EIA study;

(vii) describe all recognized sites of conservation importance in the Project area and its vicinity, in particular, the Mai Po and Inner Deep Bay Ramsar Site, and assess whether these sites will be affected by the Project or not;

(viii) using suitable methodology, identify and quantify as far as possible any direct, indirect (e.g. changes in water qualities, hydrodynamics properties, sedimentation rates and patterns, hydrology), on-site, off-site, primary, secondary and cumulative ecological impacts such as destruction of habitats, reduction of species abundance/diversity, loss of feeding grounds, reduction of ecological carrying capacity, habitat fragmentation; and in particular the following:

(a) habitat fragmentation to the Deep Bay;

(b) habitat loss and disturbance to wildlife during construction stage;

(c) impacts to the egretries;

(d) impacts to the seagrass bed, horseshoe crabs and inter-tidal mudflat;

(e) impacts to the Black-faced Spoonbill (Platalea minor), in particular, the loss of feeding habitats;

(f) impacts associated with dredging, spoil disposal, extraction and placement of fill materials during construction, and in particular to the benthic communities;

(g) impacts to the Chinese White Dolphin including noise disturbance, adverse effect caused by possible underwater blasting or percussive pilling, possible contaminants from suspended sediment, and loss of habitat and food supply;

(h) deterioration of environmental quality (e.g. water quality) and the subsequent impacts to the biological communities during operation stage;

(i) impacts to the avifauna during operational stage due to the increase in noise, air pollution, lighting, glare and physical barrier; and

(j) impacts to the Deep Bay due to the possible increase in sedimentation as a result of the change in hydrology.;

(ix) determine that the ecological impacts are avoided by design to the maximum practicable extent;

(x) evaluate the significance and acceptability of the ecological impacts identified using well-defined criteria;

(xi) recommend all possible alternatives and practicable mitigation measures to avoid, minimize and/or compensate for the adverse ecological impacts identified, such as :

(a) measures to recreate the natural inter-tidal and sub-tidal shores lost;

(b) reinstatement of habitats temporarily affected by the Project to its original state and if possible with some enhancement features;

(xii) evaluate the feasibility and effectiveness of the recommended mitigation measures and define the scope, type, location, implementation arrangement, subsequent management and maintenance of such measures;

(xiii) determine and quantify as far as possible the residual ecological impacts after implementation of the proposed mitigation measures;

(xiv) evaluate the severity and acceptability of the residual ecological impacts using well-defined criteria;

(xv) review the need for and recommend any ecological monitoring programme required.

3.4.6 Fisheries Impact

3.4.6.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing fisheries impact as stated in Annexes 9 and 17 of the TM.

3.4.6.2 The study area shall be the same as that for water quality impact assessment as set out in Section 3.4.3.2 above. It shall include the oyster beds in Deep Bay.

3.4.6.3 The study shall review and collate existing information to provide adequate and accurate data for prediction and evaluation of impacts of the Project on fisheries.

3.4.6.4 The fisheries impact assessment shall include the following:-

(i) description of the physical environmental background;

(ii) description and quantification of existing capture fisheries, pond culture and oyster farming activities;

(iii) description and quantification as far as possible the existing fisheries resources (e.g. major fisheries products and stocks);

(iv) identification of parameters (e.g. water quality parameters) and areas (e.g. breeding/spawning grounds, nursery grounds, oyster beds and fishponds) that are important to fisheries;

(v) identification and quantification as far as possible any direct/indirect impacts to fisheries (e.g. deterioration of fishing grounds, loss of breeding grounds, reduction of catch/productivity, permanent/temporary loss of fishponds and oyster beds);

(vi) evaluation of impacts and make proposals for any environmental mitigation measures with details on justification, description of scope and programme, feasibility as well as staff and financial implications including those related to subsequent management and maintenance requirements of the proposals; and

(vii) review the need for monitoring during the construction and operation phases of the Project and, if necessary, propose a monitoring and audit programme.

3.4.7 Landscape and Visual Impact

3.4.7.1 The Applicant shall follow the criteria and guidelines as stated in Annexes 10 and 18 of the TM for evaluating and assessing landscape and visual impacts of any above ground structures and work areas associate with the Project. Landscape and visual impacts during both construction and operation stages within the study area shall be assessed.

3.4.7.2 The assessment area for the landscape impact assessment shall include all areas within 500 metres from the Project. The study area for the visual impact assessment shall be defined by the visual envelope from the Project.

3.4.7.3 The Applicant shall review relevant Outline Zoning Plans, Development Permissions Area Plans, Outline Development Plans, Layout Plans, planning briefs and studies which may identify areas of high landscape value and recommend coastal protection area, conservation area and green belt designations. Any guidelines on landscape framework that may affect the appreciation of the Project should be reviewed. The aim is to gain an insight to the future outlook of the area so as to assess whether the project can fit into surrounding setting. Any conflict with statutory town plan(s) should be highlighted and appropriate follow-up action should be recommended.

3.4.7.4 The Applicant shall describe, appraise, analyze and evaluate the existing landscape resource and character of the assessment area. A system shall be derived for judging landscape and visual impact significance as required under the TM. The sensitivity of the landscape framework and its ability to accommodate change shall be particularly focused on. The Applicant shall identify the degree of compatibility of the Project with the existing and planned landscape settings. The landscape impact assessment shall quantify the potential landscape impacts as far as possible so as to illustrate the significance of such impacts arising from the Project. Clear mapping of the landscape impact is required. A tree survey shall be carried out and the impacts on existing mature trees shall be addressed.

3.4.7.5 The Applicant shall assess the visual impacts of the Project. Clear illustrations including mapping of visual impact is required. The assessment shall include the following:

(i) Identification and plotting of visual envelop of the Project;

(ii) Identification of the key groups of sensitive receivers within the visual envelope with regard to views from both ground level, sea level and elevated vantage points;

(iii) Description of the visual compatibility of the Project with the surrounding and the planned setting, and its obstruction and interference with the key views of the adjacent areas; and

(iv) The severity of visual impacts in terms of nature, distance and number of sensitive receivers shall be identified. Nighttime glare shall also be considered in the assessment. The visual impacts of the Project with and without mitigation measures shall be included so as to demonstrate the effectiveness of the proposed mitigation measures.

3.4.7.6 The Applicant shall evaluate the merits of preservation in totality, in parts or total destruction of existing landscape and the establishment of a new landscape character area. In addition, alternative alignment, design and construction methods that would avoid or reduce the identified landscape and visual impacts shall be evaluated for comparison before adopting other mitigation or compensatory measures to alleviate the impacts. The mitigation measures proposed shall not only be concerned with damage reduction but should also include consideration of potential enhancement of existing landscape. The Applicant shall recommend mitigation measures to minimize the adverse effects identified above, including provision of a landscape design.

3.4.7.7 The mitigation measures shall include preservation of vegetation, transplanting of mature trees, provision of screen planting, re-vegetation of disturbed land, compensatory planting, provision of amenity areas, design of structures, provision of finishes to structures, colour scheme and texture of material used and any measures to mitigate the impact on existing land use. Parties shall be identified for the on going management and maintenance of the proposed mitigation works to ensure their effectiveness throughout the operation phase of the Project. A practical programme and funding proposal for the implementation of the recommended measures shall be provided. For bridge structures and noise barriers, presentation of photomontages of the Project in the existing rural setting and planned setting illustrating the effectiveness of the proposed mitigation measures shall be included.

3.4.7.8 Annotated illustration materials such as coloured perspective drawings, plans and section/elevation diagrams, oblique aerial photographs, photographs taken at vantage points, and computer-generated photomontage shall be adopted to fully illustrate the landscape and visual impacts of the Project to the satisfaction of the Director. All computer graphics shall be compatible with Microstation DGN file format. The Applicant shall record the technical details such as system set-up, software, data files and function in preparing the illustration, which may need to be submitted for verification of the accuracy of the illustrations.

3.4.8 Impact on Cultural Heritage

3.4.8.1 The Applicant shall follow the criteria and guidelines for evaluating and assessing the cultural heritage impacts as stated in Annexes 10 and 19 of the TM, respectively.

3.4.8.2 The study area for terrestrial archaeological survey at the Ngau Hom Shek Archaeological Site shall include areas within 50 metres from the landing point of the SWC. The terrestrial archaeological survey shall be carried out by a qualified archaeologist who shall obtain a License from the Antiquity Authority before undertaking the field evaluation under the provision of the Antiquities and Monuments Ordinance (Cap. 53).

3.4.8.3 The Applicant shall engage a qualified marine archaeologist to review available information to identify whether there is any possible existence of sites or objects of cultural heritage, for example shipwreck, within an areas 100 metres on either side of the recommended SWC alignment and any seabed areas that would be affected by the marine works of the Project. If found, a Marine Archaeological Investigation (MAI) is required within the said area. The MAI shall be carried out by a qualified marine archaeologist who shall obtain a License from the Antiquities and Monuments Ordinance (Cap. 53). The requirements of the MAI are set out in Appendix D.

3.4.8.4 The cultural heritage impact assessment information shall include the following :

(i) The Applicant shall identify all sites of cultural heritage and establish a comprehensive inventory of these sites including relics, historic buildings, structures and graves located within or in close proximity to the project area as defined in (iii) and (iv) below, that might have the potential to be affected by the Project. A plan showing the location of both the proposed work areas and all sites of cultural heritage identified is required.

(ii) The Applicant shall demonstrate that the disturbance, including access, to those sites of cultural heritage are avoided to the maximum practicable extent by modification of layout and design of the Project. For those sites of cultural heritage that might still be directly and indirectly affected by the Project, the Applicant shall recommend practicable mitigation measures and monitoring to avoid or keep the adverse impacts on the site of cultural heritage to the minimum. A checklist including all the affected sites of cultural heritage, impacts identified, recommended mitigation measures as well as the implementation agent and period shall also be included in the EIA report.

(iii) In the event that supplementary studies are needed and agreed by the Director, the Applicant can draw necessary reference to Appendix E on the "Criteria for Cultural Heritage Impact Assessment".

3.4.9 Hazard To Life

3.4.9.1 If there is overnight storage of explosives on site and the location of which is in close vicinity of populated areas or PHI site, the Applicant shall follow the criteria for evaluating hazard to life as stated in Annexes 4 and 22 of the TM in conducting hazard assessment and include the following in the assessment :

(i) Identification of all hazardous scenarios associated with the on-site transport, storage and use of explosives for blasting operations.

(ii) Execution of a Quantitative Risk Assessment expressing population risks in both individual and societal terms.

(iii) Comparison of individual and societal risks with the Criteria for Evaluating Hazard to Life stipulated in Annex 4 of the TM; and

(iv) Identification and assessment of practicable and cost effective risk mitigation measures.

3.4.10 Summary of Environmental Outcomes

The EIA report shall contain a summary of the key environmental outcomes arising from the EIA study, including the population and environmentally sensitive areas protected, environmentally friendly designs recommended, key environmental problems avoided, compensation areas included and the environmental benefits of environmental protection measures recommended.

3.4.11 Environmental Monitoring and Audit (EM&A) Requirements

3.4.11.1 The Applicant shall identify and justify in the EIA study whether there is any need for EM&A activities during the construction and operation phases of the Project and, if affirmative, to define the scope of the EM&A requirements for the Project in the EIA study.

3.4.11.2 Subject to the confirmation of the EIA study findings, the Applicant shall comply with the requirements as stipulated in Annex 21 of the TM. The Applicant shall also propose real-time reporting of monitoring data for the Project through a dedicated internet website.

3.4.11.3 The Applicant shall prepare a project implementation schedule (in the form of a checklist as shown in Appendix F to this EIA study brief) containing all the EIA study recommendations and mitigation measures with reference to the implementation programme.

4. DURATION OF VALIDITY

4.1 This EIA study brief is valid for 24 months after the date of issue. If the EIA study does not commence within this period, the Applicant shall apply to the Director for a fresh EIA study brief before commencement of the EIA study.

5. REPORT REQUIREMENTS

5.1 In preparing the EIA report, the Applicant shall refer to Annex 11 of the TM for the contents of an EIA report. The Applicant shall also refer to Annex 20 of the TM, which stipulates the guidelines for the review of an EIA report.

5.2 The Applicant shall supply the Director with the following number of copies of the EIA report and the executive summary:

(i) 50 copies of the EIA report in English and 80 copies of the executive summary (each bilingual in both English and Chinese) as required under section 6(2) of the EIAO to be supplied at the time of application for approval of the EIA report.

(ii) when necessary, addendum to the EIA report and the executive summary submitted in 5.2 (i) above as required under section 7(1) of the EIAO, to be supplied upon advice by the Director for public inspection.

(iii) 20 copies of the EIA report in English and 50 copies of the executive summary (each bilingual in both English and Chinese) with or without Addendum as required under section 7(5) of the EIAO, to be supplied upon advice by the Director for consultation with the Advisory Council on the Environment.

5.3 The Applicant shall, upon request, make additional copies of the above documents available to the public, subject to payment by the interested parties of full costs of printing.

5.4 In addition, to facilitate the public inspection of the EIA Report via the EIAO Internet Website, the applicant shall provide electronic copies of both the EIA Report and the Executive Summary Report prepared in HyperText Markup Language (HTML) (version 4.0 or later) and in Portable Document Format (PDF version 4.0 or later), unless otherwise agreed by the Director. For the HTML version, a content page capable of providing hyperlink to each section and sub-section of the EIA Report and the Executive Summary Report shall be included in the beginning of the document. Hyperlinks to all figures, drawings and tables in the EIA Report and Executive Summary shall be provided in the main text from where the respective references are made. All graphics in the report shall be in interlaced GIF format unless otherwise agreed by the Director.

5.5 The electronic copies of the EIA report and the Executive Summary shall be submitted to the Director at the time of application for approval of the EIA Report.

5.6 When the EIA Report and the Executive Summary are made available for public inspection under s.7(1) of the EIAO, the content of the electronic copies of the EIA Report and the Executive Summary must be the same as the hard copies and the Director shall be provided with the most updated electronic copies.

5.7 To promote environmentally friendly and efficient dissemination of information, both hardcopies and electronic copies of future EM&A reports recommended by the EIA study shall be required and their format shall be agreed by the Director.

6. OTHER PROCEDURAL REQUIREMENTS

6.1 If there is any change in the name of Applicant for this EIA study brief during the course of the EIA study, the Applicant must notify the Director immediately.

6.2 If there is any key change in the scope of the Project mentioned in Section 1.2 of this EIA study brief and in Project Profile (No. PP-137/2001), the Applicant must seek confirmation from the Director in writing on whether or not the scope of issues covered by this EIA study brief can still cover the key changes, and the additional issues, if any, that the EIA study must also address. If the changes to the Project fundamentally alter the key scope of the EIA study brief, the Applicant shall apply to the Director for a fresh EIA study brief.

--- END OF EIA STUDY BRIEF ---

September 2001
Environmental Assessment and Noise Division,
Environmental Protection Department

Appendix A

Figure 1

These frequently used models are also referred to as Schedule 1 models (see attached list).

2.2 Note that both FDM and CALINE4 have a height limit on elevated sources (20 m and 10m, respectively). Source of elevation above these limits will have to be modelled using the ISCST3 model or suitable alternative models. In using the latter, reference should be made to the 'Guidelines on the Use of Alternative Computer Models in Air Quality Assessment' in Appendix B-3.

2.3 The models can be used to estimate both short-term (hourly and daily average) and long-term (annual average) ambient concentrations of air pollutants. The model results, obtained using appropriate model parameters (refer to Section 3) and assumptions, allow direct comparison with the relevant air quality standards such as the Air Quality Objectives (AQOs) for the relevant pollutant and time averaging period.

3. Model Input Requirements

3.1 Meteorological Data

3.1.1 At least 1 year of recent meteorological data (including wind speed, wind direction, stability class, ambient temperature and mixing height) from a weather station either closest to or having similar characteristics as the study site should be used to determine the highest short-term (hourly, daily) and long-term (annual) impacts at identified air sensitive receivers in that period. The amount of valid data for the period should be no less than 90 percent.

3.1.2 Alternatively, the meteorological conditions as listed below can be used to examine the worst case short-term impacts:

Day time:
stability class D; wind speed 1 m/s (at 10m height); worst-case wind angle; mixing height 500 m

Night time:
stability class F; wind speed 1 m/s (at 10m height); worst case wind angle; mixing height 500 m

This is a common practice with using the CALINE4 model due to its inability to handle lengthy data set.

3.1.3 For situations where, for example, (i) the model (such as CALINE4) does not allow easy handling of one full year of meteorological data; or (ii) model run time is a concern, the followings can be adopted in order to determine the daily and annual average impacts:

(i) perform a frequency occurrence analysis of one year of meteorological data to determine the actual wind speed (to the nearest unit of m/s), wind direction (to the nearest 10o) and stability (classes A to F) combinations and their frequency of occurrence;

(ii) determine the short term hourly impact under all of the identified wind speed, wind direction and stability combinations; and

(iii) apply the frequency data with the short term results to determine the long term (daily / annual) impacts.

Apart from the above, any alternative approach that will capture the worst possible impact values (both short term and long term) may also be considered.

3.1.4 Note that the anemometer height (relative to a datum same for the sources and receptors) at which wind speed measurements were taken at a selected station should be correctly entered in the model. These measuring positions can vary greatly from station to station and the vertical wind profile employed in the model can be grossly distorted from the real case if incorrect anemometer height is used. This will lead to unreliable concentration estimates.

3.1.5 An additional parameter, namely, the standard deviation of wind direction, σΘ, needs to be provided as input to the CALINE4 model. Typical values ofσΘ range from 12o for rural areas to 24o for highly urbanised areas under 'D' class stability. For semi-rural such as new development areas, 18o is more appropriate under the same stability condition. The following reference can be consulted for typical ranges of standard deviation of wind direction under different stability categories and surface roughness conditions.

Ref.(1): Guideline On Air Quality Models (Revised), EPA-450/2-78-027R, United States Environmental Protection Agency, July 1986.

3.2 Emission Sources

All the identified sources relevant to a process plant or a study site should be entered in the model and the emission estimated based on emission factors compiled in the AP-42 (Ref. 2) or other suitable references. The relevant sections of AP-42 and any parameters or assumptions used in deriving the emission rates (in units g/s, g/s/m or g/s/m2) as required by the model should be clearly stated for verification. The physical dimensions, location, release height and any other emission characteristics such as efflux conditions and emission pattern of the sources input to the model should also correspond to site data.

If the emission of a source varies with wind speed, the wind speed-dependent factor should be entered.

Ref.(2): Compilation of Air Pollutant Emission Factors, AP-42, 5thEdition, United States Environmental Protection Agency, January 1995.

3.3 Urban/Rural Classification

Emission sources may be located in a variety of settings. For modelling purposes these are classed as either rural or urban so as to reflect the enhanced mixing that occurs over urban areas due to the presence of buildings and urban heat effects. The selection of either rural or urban dispersion coefficients in a specific application should follow a land use classification procedure. If the land use types including industrial, commercial and residential uses account for 50% or more of an area within 3 km radius from the source, the site is classified as urban; otherwise, it is classed as rural.

3.4 Surface Roughness Height

This parameter is closely related to the land use characteristics of a study area and associated with the roughness element height. As a first approximation, the surface roughness can be estimated as 3 to 10 percent of the average height of physical structures. Typical values used for urban and new development areas are 370 cm and 100 cm, respectively.

3.5 Receptors

These include discrete receptors representing all the identified air sensitive receivers at their appropriate locations and elevations and any other discrete or grid receptors for supplementary information. A receptor grid, whether Cartesian or Polar, may be used to generate results for contour outputs.

3.6 Particle Size Classes

In evaluating the impacts of dust-emitting activities, suitable dust size categories relevant to the dust sources concerned with reasonable breakdown in TSP (< 30 μm) and RSP (< 10 μm) compositions should be used.

3.7 NO2 to NOx Ratio

The conversion of NOx to NO2 is a result of a series of complex photochemical reactions and has implications on the prediction of near field impacts of traffic emissions. Until further data are available, three approaches are currently acceptable in the determination of NO2:

(a) Ambient Ratio Method (ARM) - assuming 20% of NOx to be NO2; or

(b) Discrete Parcel Method (DPM, available in the CALINE4 model); or

(c) Ozone Limiting Method (OLM) - assuming the tailpipe NO2 emission to be 7.5% of NOx and the background ozone concentration to be in the range of 57 to 68 μg/m3 depending on the land use type (see also the reference paper 'Guidelines on Assessing the 'TOTAL' Air Quality Impacts' in Appendix B-2).

3.8 Plume Rise Options

The ISCST3 model provides by default a list of the U.S. regulatory options for concentration calculations. These are all applicable to the Hong Kong situations except for the 'Final Plume Rise' option. As the distance between sources and receptors are generally fairly close, the non-regulatory option of 'Gradual Plume Rise' should be used instead to give more accurate estimate of near-field impacts due to plume emission. However, the 'Final Plume Rise' option may still be used for assessing the impacts of distant sources.

3.9 Portal Emissions

These include traffic emissions from tunnel portals and any other similar openings and are generally modelled as volume sources according to the PIARC 91 (or more up-to-date version) recommendations (Ref. 3, section III.2). For emissions arising from underpasses or any horizontal openings of the like, these are treated as area or point sources depending on the source physical dimensions. In all these situations, the ISCST3 model or more sophisticated models will have to be used instead of the CALINE4 model. In the case of portal emissions with significant horizontal exit velocity which cannot be handled by the ISCST3 model, the impacts may be estimated by the TOP model (Ref. 4) or any other suitable models subject to prior agreement with EPD. The 'Guidelines on the Use of Alternative Computer Models in Air Quality Assessment' should also be referred to in Appendix B-3.

Ref.(3): XIXth World Road Congress Report, Permanent International Association of Road Congresses (PIARC), 1991.

Ref.(4): N. Ukegunchi, H. Okamoto and Y. Ide "Prediction of vehicular emission pollution around a tunnel mouth", Proceedings 4th International Clean Air Congress, pp. 205-207, Tokyo, 1977.

3.10 Background Concentrations

Background concentrations are required to account for far-field sources which cannot be estimated by the model. These values, to be used in conjunction with model results for assessing the total impacts, should be based on long term average of monitoring data at location representative of the study site. Please make reference to the paper 'Guidelines on Assessing the 'TOTAL' Air Quality Impacts' in Appendix B-2 for further information.

3.11 Output

The highest short-term and long-term averages of pollutant concentrations at prescribed receptor locations are output by the model and to be compared against the relevant air quality standards specified for the relevant pollutant. Contours of pollutant concentration are also required for indicating the general impacts of emissions over a study area.

Copies of model files in electronic format should also be provided for EPD's reference.

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Schedule 1

Air Quality Models Generally Accepted by
Hong Kong Environmental Protection Department for
Regulatory Applications as at 1 July 1998

Industrial Source Complex Dispersion Model - Short Term Version 3 (ISCST3) or the latest version developed by U.S. Environmental Protection Agency

California Line Source Dispersion Model Version 4 (CALINE4) or the latest version developed by Department of Transportation, State of California, U.S.A.

Fugitive Dust Model (FDM) or the latest version developed by U.S. Environmental Protection Agency