1. BACKGROUND

1.1 An application (No. ESB-082/2001) 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 9 August 2001 with a Project Profile (No. PP-138/2001) for the captioned project.

1.2 The project is part of the "Yuen Long and Kam Tin Sewerage and Sewage Disposal" (YLKTSSD) scheme recommended by the "Review of Yuen Long and Kam Tin Sewerage and Sewage Treatment Requirements". The YLKTSSD scheme is aimed at phased implementation of sewerage extension in the Northwest New Territories to cope with existing and planned developments. The YLKTSSD scheme consists of the following elements:

(i) YLKTSSD Stage 1;

(ii) YLKTSSD Stage 2; and

(iii) the Upgrading and Expansion of San Wai Sewage Treatment Works and Expansion of Ha Tsuen Pumping Station.

1.3 The project profile (No. PP-049/1999) of Stage 1 of the YLKTSSD was submitted by the Project Management Division of Drainage Services Department under Section 5(1) of the Environmental Impact Assessment Ordinance (EIAO) on 6 May 1999. The EIA Study will be dealt with in accordance to the EIA Study Brief (No. ESB-033/1999) issued under Section 5(7) of EIAO on 17 June 1999

1.4 The project profile (No. PP-100/2000) of the Upgrading and Expansion of San Wai Sewage Treatment Works and Expansion of Ha Tsuen Pumping Station was submitted by the Project Management Division of Drainage Services Department under Section 5(1) of the EIAO on 9 August 2000. The EIA Study Brief (No.: ESB-059/2000) was issued under Section 5(7) of EIAO on 20 September 2000.

1.5 The current project covered in the project profile (No. PP-138/2001) for the YLKTSSD Stage 2 is identified to contain three DP for packages 2A-1T, 2A-2T and 2B-1T and two DP for the alternative of package 2A-1T. They are described as follow:

(a) Package 2A-1T - Yuen Long Sewage Treatment Works (YLSTW) Effluent Pipeline

• OP1-Pumping Station in the north of YLSTW by virtue of Item Q.1 of Schedule 2, Part I under the EIAO
• OS1- Twin rising mains from item OP1 to Tin Tze Road in Tin Shui Wai by virtue of Item Q.1 of Schedule 2, Part I under EIAO

(b) Alternative to Package 2A-1T- Yuen Long Sewage Treatment Works (YLSTW) Effluent Pipeline

• AP1- Pumping Station in the north of YLSTW by virtue of Item Q.1 of Schedule 2, Part I under the EIAO
• AS1- Twin rising mains in the northwestern side of YLSTW by virtue of Item Q.1 of Schedule 2, Part I under the EIAO

(c) Package 2A-2T - Ngau Tam Mei/ San Tin Trunk Sewerage Phase 1 and Package 2B-1T - Ngau Tam Mei/ San Tin Trunk Sewerage Phase 2

• P1- Ngau Tam Mei Sewage Pumping Station by virtue of F.3(b) of Schedule 2, Part I under the EIAO

The locations and alignments of the proposed project are shown in fig.1 to fig. 6 of the study brief.

1.6 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.

1.7 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 proposed project and related activities taking 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 proposed project;

(ii) the conditions and requirements for the detailed design, construction and operation of the proposed 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 proposed project and associated works together with the requirements for carrying out the proposed project;

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

(iii) to identify and quantify emission sources and determine the significance of impacts on sensitive receivers e.g. Fairview Park and potential affected uses such as the future residential development in Fung Lok Wai and the committed Hung Shui Kiu New Development Area;

(iv) to identify any potential impacts from point and non-point pollution sources on the identified water systems and sensitive receivers during the construction and operation stages;

(v) to identify and quantify any potential losses and damage to flora, fauna and wildlife habitats;

(vi) to identify, quantify, where applicable, any potential landscape and visual impacts arising from e.g. the loss of fishponds, wetlands, trees or vegetation and determine the significance of impacts on any existing e.g. Fairview Park or planned sensitive receivers such as the proposed residential development at Fung Lok Wai during the construction or operation phase of the project;

(vii) to identify any potential impacts to the historical, archaeological and cultural resources during construction and operation of the project and propose measures to mitigate these impacts;

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

(ix) to identify, predict and evaluate the residual (i.e. after practicable mitigation) environmental impacts, the cumulative effects expected to arise due to other committed or planned development(s) at area near the project site and the total environmental impacts of the projects under the YLKTSSD including (i)YLKTSSD Stage 1; (ii) YLKTSSD Stage 2; and (iii) the Upgrading and Expansion of San Wai Sewage Treatment Works and Expansion of Ha Tsuen Pumping Station project during the construction and operation phases of the proposed project in relation to the sensitive receivers and potential affected uses;

(x) to identify, assess and specify methods, measures and standards, to be included in the detailed design, construction and operation of the proposed project, which are necessary to mitigate these environmental impacts and reducing them to acceptable levels;

(xi) to investigate the residual impacts of the proposed mitigation measures that may lead to other forms of impacts;

(xii) to identify constraints associated with the mitigation measures recommended in the EIA study;

(xiii) to design and specify the environmental monitoring and audit requirements, if required, to ensure the implementation and the effectiveness of the environmental protection and pollution control measures adopted; and

(xiv) to consider alternatives with a view to avoiding or minimizing the potential environmental impacts on but not limited to (i) area(s) of high ecological value such as the Wetland Conservation Area (WCA)/Wetland Buffer Area (WBA), Conservation Area (CA) zone such as the CA zone near Shan Pui River, egretries in vicinity of the project area such as the egretry at the north of Wang Chau Fresh Water Service Reservoir and Mai Po Egretry, habitats such as the mudflats along the coast from Tsim Bei Tsui to Pak Nai inhabited by wintering Black-faced Spoonbills, the coastal habitats at Lau Fau Shan inhabited by migratory shorebirds; and (ii) other sensitive uses including residential development, school, place of worship or home for the aged; and to compare the environmental benefits and dis-benefits of each of the different option and to provide reasons for selecting the preferred option(s) and to describe the part environmental factors played in the selection.

3. DETAILED REQUIREMENTS OF THE EIA STUDY

3.1 The Purpose

3.1.1 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 EIA Process of the EIAO (hereinafter referred to as the TM) are fully complied with.

3.2 The Scope

The scope of this EIA study covers the proposed project mentioned in the project profile (No.: PP-138/2001). The EIA study shall address the likely key issues described below; together with any key issues identified during the course of the EIA study.

(i) the potential impacts on the Wetland Conservation Area (WCA)/Wetland Buffer Area (WBA), Conservation Area (CA) zone such as the CA zone near Shan Pui River, egretries in the vicinity of the project area such as the egretry at the north of Wang Chau Fresh Water Service Reservoir and Mai Po Egretry, habitats such as the mudflats along the coast from Tsim Bei Tsui to Pak Nai inhabited by wintering Black-faced Spoonbills, the coastal habitats at Lau Fau Shan inhabited by migratory shorebirds and any identified area(s) of high ecological value including natural and man made habitats during the course of study;

(ii) the potential noise and air quality impacts on sensitive receivers during the construction and operational phases, in particular at areas near or within the CA zone, the egretries, school(s), village houses and other residential quarters/dwellings;

(iii) the potential aquatic and terrestrial ecological impacts arising from the construction and operation activities, including loss of habitats, removal of vegetation and disturbance to animals. The assessment shall fully address all direct, indirect, total and cumulative impacts on the integrity and viability of area(s) including Lau Fau Shan, Mong Tseng, San Wai, Tin Shui Wai, Shap Pat Heung, Ngau Tam Mei, San Tin and Mai Po resulting from other proposed and existing projects e.g. the San Tin Drainage Project and the residential development at Fung Lok Wai;

(iv) the potential impacts on any historical, archaeological and cultural heritages during construction and operation of the project and propose measures to mitigate these impacts;

(v) any ecological, landscape and visual impacts or any impact on sensitive receivers within the work boundaries of each of the works item. Adverse environmental impacts within the work boundaries or off-site nuisances should be fully addressed and mitigated; and

(vi) the cumulative effects expected to arise due to other committed or planned development(s) at area near the project site and the total environmental impacts of the projects under the YLKTSSD including (i)YLKTSSD Stage 1; (ii) YLKTSSD Stage 2; and (iii) the Upgrading and Expansion of San Wai Sewage Treatment Works and Expansion of Ha Tsuen Pumping Station project during the construction and operation phases of the proposed project in relation to the sensitive receivers and potential affected uses.

3.3 Alternatives Alignments/Locations, Design of Alignments and Construction Methods

3.3.1 Alternative Alignments/Location

The study shall include the consideration of alternative alignments/locations together with a "no-built" alternative. The Applicant shall compare the environmental impacts of these options and provide reasons for selecting the proposed system and alignment/location with reference to any environmental factors taken into consideration during the course of selection. In considering the alternative alignments/locations, consideration shall be given to avoiding/minimizing the negative effect on (i) area(s) of high ecological value such as the Wetland Conservation Area (WCA)/Wetland Buffer Area (WBA), Conservation Area (CA) zone such as the CA zone near Shan Pui River, the egretries in vicinity of the project area e.g. the egretry habitat located at the foothill on the north of Wang Chau Fresh Water Service Reservoir and the Mai Po Egretry, habitats such as the mudflats along the coast from Tsim Bei Tsui to Pak Nai inhabited by wintering Black-faced Spoonbills, the coastal habitats at Lau Fau Shan inhabited by migratory shorebirds and (ii) any sensitive area including but not limited to any planned or existing residential development, school, place of worship or home for the aged

An evaluation system shall be set up to assess the environmental benefits and disbenefits of all possible options. The potential impacts on (i) area(s) of high ecological value mentioned in 3.3.1 above and (ii) any sensitive area including but not limited to any planned or existing residential development, school, place of worship or home for the aged, are key issue to the evaluation system. The final recommended development option(s) and alignment option(s) should be well assessed and justified especially on whether the option(s) will affect (i) area(s) of high ecological value mentioned in section 3.3.1 above and (ii) any of the sensitive area mentioned above.

3.3.2 Alternative Design of Alignments

Alternative design of the sewerage system e.g. underground sewage pipeline shall be considered to avoid or minimize any direct, indirect and cumulative impacts and impacts on sensitive receivers including any planned or existing developments such as but not limited to the CA zone, egretries and the residential development e.g. Fairview Park and the future residential development in Fung Lok Wai.

3.3.3 Consideration of Alternative Construction Methods and Sequences of Works

Having regard to the cumulative effects of the construction period and the severity of the construction impacts to the sensitive receivers, the EIA study shall also explore alternative construction methods and sequences of works for the proposed project with a view to avoid adverse environmental impacts to the maximum practicable extent. A comparison of the environmental benefits and dis-benefits of applying different construction methods shall be made. The Applicant shall take into account the environmental implications of site run-off especially during construction phase in wet seasons.

3.3.4 Taking into the comparison in sections 3.3.1, 3.3.2 and 3.3.3 above, the Applicant shall recommend/justify the adoption of the different options of alignments/locations, alternative design of alignments and alternative of construction methods that will avoid or minimize adverse environmental effects, in particular the ecological impacts.

3.4 Technical Requirements

The Applicant shall conduct the EIA study to address all environmental aspects of the activities as described in the scope as set out above and subject to the findings under section 3.3. 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 assessment area for the air quality impact assessment shall generally be defined by a distance of 500 m from the boundary of the project works sites, yet it may be extended depending on the circumstances and the scale of the project.

3.4.1.3 The Applicant shall access the air pollutant concentrations with reference to the relevant sections of the guidelines attached with this Study Brief in Appendices A-I to A-III, or other methodology as agreed by the Director.

3.4.1.4 The air quality assessment shall include the following:

Background and analysis of activities

(i) Provide background information relating to air quality issues relevant to the project, e.g. description of the types of activities of the project.

(ii) 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 minimise the constructional and operational air quality impact.

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

Identification of Air Sensitive Receivers (ASRs) and examination of emission/dispersion characteristics

(iv) Identify and describe representative existing and planned/committed ASRs that would likely be affected by the project. The Applicant shall select the assessment points of the identified ASRs such that they represent the worst impact point on these ASRs. A map showing the location and a description including the name of the buildings, their uses and height of the selected assessment points shall be given. The separation distances of these ASRs from the nearest emission sources should also be given.

(v) Provide an exhaustive list of air pollutant emission sources, including any nearby emission sources, which are likely to have impact on the project based on the analysis of the constructional and operational activities of the project in (i) above.

Constructional air quality impact

(vi) The Applicant shall follow the requirements of the Air Pollution Control (Construction Dust) Regulation in dust control to ensure construction dust impacts are controlled within the relevant standards as stipulated in section 1 of Annex 4 of the TM. An audit and monitoring program during constructional stage shall be initiated to verify the effectiveness of the control measures and to ensure that the construction dust levels be brought under control.

(vii) If the Applicant anticipates a significant construction dust impact that will likely cause exceedance of the recommended limits in the TM at the ASRs despite incorporation of the dust control measures stated in (vi) above, a quantitative assessment should be carried out to evaluate the construction dust impact at the identified ASRs based on the emission strength of the emission sources identified in (v) above. The Applicant shall follow (ix) to (xiii) below when carrying out the quantitative assessment.

Operational air quality impact

(viii) The Applicant shall calculate the expected air pollutant concentrations (e.g. emission of hydrogen sulphide and odour) at the identified ASRs. Calculations shall be based on an assumed reasonably worst-case scenario. The evaluation shall be based on the strength of the emission sources identified in (v) above. The Applicant shall follow (ix) to (xiii) below when carrying out the quantitative assessment.

Quantitative Assessment Methodology

(ix) The Applicant shall apply the general principles enunciated in the modelling guidelines in Appendices A-I to A-III while making allowance for the specific characteristic of each project. Specific methodology must be documented to such level of detail (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 modelling 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 of the general methodology between the Applicant and the Director is required.

(x) The Applicant shall identify the key/representative air pollutant parameters related to construction activities (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.

(xi) 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 tables and pollution contours, for comparison with relevant air quality standards and for examination of the land use implications of these impacts. Plans of suitable scale should be used for presentation of pollution contours for determining buffer distances required.

Mitigating Measures for Non-compliance

(xii) 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 proposed mitigating measures will comply with the criteria stipulated in section 1 of Annex 4 in the TM.

Submission of Model Files

(xiii) 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 "Assessment Area" for the noise impact assessment shall include all areas within 300 m from the project boundary. Subject to the agreement of the Director, the assessment area could be reduced accordingly if the first layer of noise sensitive receivers, closer than 300 m from the project boundary, provides acoustic shielding to those receivers further from the site.

(ii) Provision of Background Information and Existing Noise Levels

The Applicant shall provide all background information relevant to the project, including relevant previous or current studies. Unless necessary for planning standards, it will not be necessary to investigate the existing noise levels.

(iii) Identification of Noise Sensitive Receivers

(a) The Applicant shall refer to Annex 13 of the TM when identifying the noise sensitive receivers (NSRs). The NSRs shall include all existing NSRs and all planned/committed noise sensitive developments and uses earmarked on the relevant Outline Zoning Plans, Outline Development Plans, Layout Plans and other published plans, including any land use and development applications approved by Town Planning Board. For planned noise sensitive land uses without committed layouts, the Applicant shall work out indicative site layouts based on the relevant planning parameters.

(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.

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

The Applicant shall provide an inventory of noise sources including construction equipment and pumping station for both construction and operational noise assessment. Confirmation of the validity of the inventory shall be obtained from the relevant government departments/authorities.

(v) Construction Noise Assessment

(a) The Applicant shall carry out assessment of noise impact from construction (excluding percussive piling) of proposed 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 explored and recommended as far as practicable.

(c) If the unmitigated construction noise levels are found to exceed 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) The applicant shall confirm whether construction work during restricted hours is required. If affirmative, the applicant shall 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 shall 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 (Pumping Stations)

(a) The Applicant shall calculate the expected noise from the operation of all pumping stations OP1, AP1, P1, P2, P3, P4, P5, A1, A2, B1, B2, B3, B4, B5, B6 and B7 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 of 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.

(b) The Applicant shall present the existing and future noise levels in Leq (30 mins) at the NSRs at various representative floor levels (in mPD) on tables and plans of suitable scales. Quantitative assessment at the NSRs for 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.

(c) The Applicant shall propose direct technical remedies within the project limits in all situations where the predicted noise levels exceed the criteria set out in Table 1A of Annex 5 of the TM to protect all 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/Land Uses

(a) In the event that there are 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.

(b) The Applicant shall take into account the agreed environmental requirements/ constraints identified by the study to assess the development potential of the 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 assessment area for the water quality impact assessment shall include all areas within 500m from the project boundary, plus any stream courses and the associated water system in the vicinity that will be affected by the project.

3.4.3.3 The Applicant shall identify and analyze all physical, chemical and biological disruptions arising from construction and operation of the project including those potentially caused by accidental toxic spillages, in particular but not limited to the fish ponds in the Conservation Area near Shan Pui River and any other water system identified during the course of study. The potential impact of sewage derived from the construction and operation stages on the Conservation Area and identified water system and sensitive receivers shall also be assessed and evaluated.

3.4.3.4 By making reference to any water quality modelling results in other studies as necessary, this EIA study shall cover the assessment on the cumulative water quality impacts on the following aspects including the cumulative water quality impacts with other concurrent projects, and the cumulative water quality impacts arises from all the operation of the Yuen Long Kam Tin Sewerage and Sewage Disposal Scheme on Deep Bay. The scheme consists of the following projects:

(i) Yuen Long and Kam Tin Sewerage and Sewage Disposal Scheme Stage 1;

(ii) Yuen Long and Kam Tin Sewerage and Sewage Disposal Scheme Stage 2;

(iii) Upgrading and Expansion of San Wai Sewage Treatment Works and Expansion of Ha Tsuen Pumping Station.

3.4.3.5 The Applicant shall include the followings in the water quality impact assessment:

(i) collection and review of background information on the existing water systems and their respective catchments, and sensitive receivers which might be potentially affected by the proposed project both during construction and operation;

(ii) based on the collected information, characterize the water and sediment quality of the surrounding water systems and sensitive receivers which might be potentially affected by the proposed project both during construction and operation. This shall be supplemented by additional field survey and sampling as necessary;

(iii) collation of pertinent water quality objectives, criteria and standards for the water system(s) and all the sensitive receivers in (i) above;

(iv) identification and quantification of all dredging, filling and excavation activities which might lead to alteration of water systems in (i), change of flow regimes and change of catchment areas. Mud/sediment transportation and disposal activities and requirements and potential fill sources and dumping grounds to be used shall be identified;

(v) field investigation, sampling and laboratory tests to characterize the sediment/mud concerned in (iv) shall be conducted as appropriate. The ranges of parameters to be analyzed; the number, type and methods of sampling, sampling protocols and laboratory to be used shall be subject to the agreement of the Director;

(vi) prediction and quantification, by technique subject to agreement of the Director, of impacts on the water systems and the sensitive receivers due to those changes, alterations and activities identified in above. Possible impacts caused by, amongst others, sediment re-suspension and contaminants release shall be predicted and assessed by technique mentioned above. The effects on aquatic organisms, fish pond habitats and sensitive receivers due to such changes and activities shall also be predicted and assessed appropriately. The prediction shall include possible different construction stages or sequences. Possible cumulative impacts exacerbated by other concurrent projects, activities or pollution sources shall be identified, predicted and quantified;

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

(viii) identification, assessment and evaluation of surface run-off and stormwater impacts, including any potential chemical and toxic substance spillages, release of oils and lubricants and use of cleaning agents and pesticides, on the identified systems and sensitive receivers during both construction and operation stages. Best Management Practices (BMPs) shall be recommended to reduce potential impacts to within standards, objectives and criteria established in (iii) above;

(ix) assessment and evaluation of any potential water quality impacts on the identified water systems and sensitive receivers due to sewage derived from the construction and operation stages;

(x) a contingency plan suggesting measures to handle accidental failure of the pumping facilities or the blockage and damage of the rising mains/sewers shall be recommended, taking into account the risk assessment arising due to such failures; and

(xi) appropriate mitigation measures shall be recommended to alleviate all potential impacts identified above and residual or mitigated impacts shall be predicted and in compliance with all established objectives, criteria and standards identified in (iii) above both during construction and operation of the proposed project.

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

Identification of the quantity, quality and timing of the waste arising as a result of the construction and operation activities, 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 and on-site or off-site re-use 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. Preventive measures to avoid the dumping of waste at nearby wetlands should also be addressed. The disposal method recommended for each type of waste shall take into account the result of the assessment in (c) below; and

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

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

3.4.5 Land Contamination Impact

3.4.5.1 The Applicant shall identify all land lots/sites within the study area boundary which, due to their past or present land uses, are potential contaminated sites. A detailed account of the present activities and past land history in relation to possible land contamination should be provided.

3.4.5.2 The list of potential contaminants which are anticipated to be found in these potential contaminated sites should be provided and the possible remediation options should be discussed.

3.4.6 Ecological Impact (Both Terrestrial and Aquatic)

3.4.6.1 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. The assessment area for the purpose of terrestrial ecological assessment shall include all areas within 500 m distance from the site boundary of the works areas, or the area likely to be impacted by the proposed projects. For aquatic ecology, the assessment area shall be the same as for water quality assessment described in Section 3.4.3.2.

3.4.6.2 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 existing natural environment. The assessment shall identify and quantify as far as possible the potential ecological impacts associated with the project, including the impacts of any haul roads and temporary access.

3.4.6.3 The assessment shall include the following:

(i) A review of the findings of relevant studies and collating all the available information regarding the ecological characters of the assessment area;

(ii) Evaluation of the information collected and identification of any information gap relating to the assessment of potential ecological impacts to the terrestrial and aquatic environment;

(iii) Carrying out the necessary field surveys (the duration of which shall be at least 6 months and covers wet and dry seasons) and investigations to verify the information collected, fill the information gaps identified and fulfill the objectives of the EIA study;

(iv) Establishing the general ecological profile and describing the characteristics of each habitat found; major information to be provided shall include:

(a) Description of the physical environment;

(b) Preparation of habitat maps of suitable scale (1:1000 to 1:5000) showing the types and locations of habitats in the assessment area;

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

(d) Presentation of representative color photos of each habitat type and of any important ecological features identified;

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

(v) Investigation and description of the existing wildlife uses of various habitats with special attention to those wildlife groups and habitats with conservation interest including:

(a) Wetland;

(b) Fishponds;

(c) Egretries (e.g. the egretry recently established at the foothill on the north of Wan Chau Fresh Water Service Reservior);

(d) Avifauna, in particular herons, egrets (representative data during the breeding season of egrets/herons and winter migratory bird season shall be provided); and

(e) Any other habitats and wildlife groups identified as having special conservation interests by the study.

(vi) Description of all recognized sites of conservation importance in the proposed development site and its vicinity and assessment of any potential impacts from different alignments and design proposals options on the specified sites including the Wetland Conservation Area (WCA)/Wetland Buffer Area (WBA), Conservation Area (CA) zone, the egretries in vicinity of the project area;

(vii) Using suitable methodology, identification and quantification as far as possible of any direct, indirect, on-site, off-site, primary, secondary and cumulative ecological impacts such as destruction of habitats, reduction of species abundance/diversity, loss of feeding, nesting and/or breeding grounds, reduction of ecological carrying capacity, habitat fragmentation; and in particular the following;

(a) Ecological impact of the potential loss of fishponds/wetland, particularly those within WCA/WBA and Fung Lok Wai;

(b) Disturbance to wildlife during construction stage, in particular, the impact to the egretries;

(c) Impact upon committed ecological mitigation areas for other projects (e.g. Main Drainage Channel for Yuen Long and Kam Tin);

(d) Cumulative impacts due to the proposed project of the Yuen Long and Kam Tin Sewerage and Sewage Disposal Stage 2 project and other planned and committed development projects at or near the project areas.

(e) Potential ecological impact due to the bypass of sewage to the environment in case of the accidental failure of the pumping facilities or the blockage and damage of the rising main sewers taking into account the risk of such failure.

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

(ix) Recommendations for alternative subject to the findings of Section 3.3.4 and practicable mitigation measures to avoid, minimize and/or compensate for the adverse ecological impacts identified such as:

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

(b) wetland compensation; and

(c) phasing of programme to avoid construction work in certain periods.

(x) Evaluation of the feasibility and effectiveness of the recommended mitigation measures and definition of the scope, type, location, implementation arrangement, resources requirement, subsequent management and maintenance of such measures

(xi) Determination and quantification as far as possible of the residual ecological impacts after implementation of the proposed mitigation measures;

(xii) Evaluation of the severity and acceptability of the residual ecological impacts using well-defined criteria, and recommendation of any necessary off-site mitigation; and

(xiii) A review of the need for and recommendation for any ecological monitoring programme required.

3.4.7 Fisheries Impact

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

3.4.7.2 The assessment area shall include but not limited to the fish ponds in the Conservation Area near Shan Pui River and any other water system identified for fisheries purpose during the course of study.

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

3.4.7.4 The fisheries impact assessment shall include the following major tasks:

(i) Description of the physical environmental background;

(ii) Description and quantification of the existing fisheries activities;

(iii) Description and quantification of the existing fisheries resources;

(iv) Identification of parameters and areas that are important of fisheries;

(v) Identification and quantification of any direct, indirect, on-site and off-site impacts to fisheries;

(vi) Evaluation of impacts and proposals for any practical alternatives or mitigation measures to prevent or minimize adverse impacts on fisheries; and

(vii) A review of the need for and recommendations of any fisheries monitoring and audit programme required.

3.4.8 Landscape and Visual Impact

3.4.8.1 The Applicant shall follow the criteria and guidelines as stated in Annexes 10 and 18 of the Technical Memorandum for evaluating and assessing landscape arid visual impacts of any above ground structures and work areas associated with the proposed project. Landscape and visual impacts during both construction and operation phases within the Study Area shall be assessed.

3.4.8.2 The assessment area for landscape impact assessment shall include all areas within a 500m distance from the proposed project while the assessment area for the visual impact assessment shall be defined by the visual envelope of the project.

3.4.8.3 The Applicant shall review relevant outline development plan(s), outline zoning plan(s), layout plan(s) or planning briefs and studies which may identify areas of high landscape value and recommend green belt and conservation area designations. The aim is to gain an insight to the future outlook of the area affected so as to assess whether the project can fit into the surrounding setting. Any conflict with statutory town plan(s) should be highlighted and appropriate follow-up action should be recommended.

3.4.8.4 The Applicant shall describe, appraise, analyze and evaluate the existing landscape resources and character of the assessment area. A system should be derived for judging landscape and visual impact significance as required under the Technical Memorandum. 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 proposed project with the existing and planned landscape setting. The landscape impact assessment shall quantify the potential landscape impact as far as possible so as to illustrate the significance of such impacts arising from the proposed development. 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.

3.4.8.5 The Applicant shall assess the visual impacts of the proposed project. Clear illustration including mapping of visual impact is required. The assessment shall include the following:

(i) identification and plotting of visual envelope of the proposed project within the assessment area;

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

(iii) description of the visual compatibility of the project such as channel wall, possible inflatable dam and associated pumping station with the surrounding and the planned setting, and its obstruction arid interference with key views of the adjacent areas; and

(iv) the severity of visual impacts in terms of distance, nature and number of sensitive receivers shall be identified. 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.

3.4.8.6 The Applicant shall evaluate the merits of preservation in totality, in parts of total destruction of existing landscape. In addition, alternative alignment design and construction method that would avoid or reduce the landscape and visual impact 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.

3.4.8.7 The mitigation measures shall also include the preservation of vegetation, transplanting of mature trees, provision of screen planting, re-vegetation of disturbed lands, compensatory planting, design of structure, provision of finishes to structure, colour scheme and texture of material used and any measures to mitigate the disturbance of the 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.

3.4.8.8 Colour perspective drawing, plans and section/elevation diagrams, annotated oblique aerial photographs, photographs taken at vantage points, and computer-generated photomontage shall be adopted to illustrate the landscape and visual impacts of the proposed project to the satisfaction of the Director. The Applicant shall record the technical details in preparing the illustration, which may need to be submitted for verification of the accuracy of the illustration.

3.4.9 Impact on Cultural Heritage

3.4.9.1 The cultural heritage study shall assess both direct and indirect impacts on the archaeological sites, historical buildings and structures as well as identifying other unknown items of archaeological and historical interests along or close to the alignment of the project, and propose the appropriate mitigation measures according to the requirements set out in Appendix B.

3.4.9.2 Study requirements for the Cultural Heritage Impact Assessment are detailed in Appendix B. The locations of Antiquities and Monuments Office's potential heritage sites are shown in fig.7 to fig.16.

4. ENVIRONMENTAL MONITORING & AUDIT (EM&A) REQUIREMENTS

4.1 The Applicant shall identify 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.

4.2 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.

4.3 The Applicant shall prepare a project implementation schedule (in the form of a checklist) containing all the EIA study recommendations and mitigation measures with reference to the implementation programme.

5. SUMMARY OF ENVIRONMENTAL OUTCOMES

5.1 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, and environmental benefits of environmental protection measures recommended.

6. DURATION OF VALIDITY

6.1 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.

7. REPORT REQUIREMENTS

7.1 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.

7.2 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, any addendum to the EIA report and the executive summary submitted in (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.

7.3 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.

7.4 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 Hyper Text 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 hyperlinks 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.

7.5 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.

7.6 When the EIA Report and the Executive Summary are made available for public inspection under section 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 up to date electronic copies.

7.7 To promote environmentally friendly and efficient dissemination of information, both hard copies 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.

8. OTHER PROCEDURAL REQUIREMENTS

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

8.2 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-138/2001), 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-I

Guidelines on Choice of Models and Model Parameters

1. Introduction

1.1 To expedite the review process by the Authority and to assist project proponents or environmental consultants with the conduct of air quality modeling exercises which are frequently called for as part of environmental impact assessment studies, this paper describes the usage and requirements of a few commonly used air quality models.

2. Choice of models

2.1 The models which have been most commonly used in air quality impact assessments, due partly to their ease of use and partly to the quick turn-around time for results, are of Gaussian type and designed for use in simple terrain under uniform wind flow. There are circumstances when these models are not suitable for ambient concentration estimates and other types of models such as physical, numerical or mesoscale models will have to be used. In situations where topographic, terrain or obstruction effects are minimal between source and receptor, the following Gaussian model can be used to estimate the near-field impacts of a number of source types including dust, traffic and industrial emissions.

These frequently used models are also referred to as Schedule 1models (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'.

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 A-III) 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 ofσΘrange 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 Odour Impact

In assessing odour impacts, a much shorter time-averaging period of 5 seconds is required due to the shorter exposure period tolerable by human receptors. Conversion of model computed hourly average results to 5-second values is therefore necessary to enable comparison against recommended standard. The hourly concentration is first converted to 3-minute average value according to a power law relationship which is stability dependent (Ref. 3) and a result of the statistical nature of atmospheric turbulence. Another conversion factor (10 for unstable conditions and 5 for neutral to stable conditions) is then applied to convert the 3-minute average to 5-second average (Ref. 4). In summary, to convert the hourly results to 5-second averages, the following factors can be applied:

Under 'D' class stability, the 5-second concentration is approximately 10 times the hourly average result. Note, however, that the combined use of such conversion factors together with the ISCST results may not be suitable for assessing the extreme close-up impacts of odour sources.

Ref.(3): Richard A. Duffee, Martha A. O' Brien and Ned Ostojic, 'Odor Modeling - Why and How', Recent Developments and Current Practices in Odor Regulations, Controls and Technology, Air & Waste Management Association, 1991.

Ref.(4): A.W.C. Keddie, 'Dispersion of Odours', Odour Control - A Concise Guide, Warren Spring Laboratory, 1980.

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 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. Refer to EPD reference paper 'Guidelines on Assessing the 'TOTAL' Air Quality Impacts' for further information.

3.10 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.

Modelling Section, Air Policy Group
Environmental Protection Department
March 2000

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 ¡V 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

* EPD is continually reviewing the latest development in air quality models and will update this Schedule accordingly

Appendix A-II

Guidelines on Assessing the 'TOTAL' Air Quality Impacts

1. Total Impacts - 3 Major Contributions

1.1 In evaluating the air quality impacts of a proposed project upon air sensitive receivers, contributions from three classes of emission sources depending on their distance from the site should be considered. These are:

2. Nature of Emissions

2.1 Primary contributions

In most cases, the project-induced emissions are fairly well defined and quite often (but not necessarily) the major contributor to local air quality impacts. Examples include those due to traffic network, building or road construction projects.

2.2 Secondary contributions

Within the immediate neighbourhood of the project site, there are usually pollutant emitting activities contributing further to local air quality impacts. For most local scale projects, any emission sources in an area within 500m radius of the project site with notable impacts should be identified and included in an air quality assessment to cover the short-range contributions. In the exceptional cases where there is one or more significant sources nearby, the study area may have to be extended or alternative estimation approach employed to ensure these impacts are reasonably accounted for.

2.3 Background contributions

The above two types of emission contributions should account for, to a great extent, the air quality impacts upon local air sensitive receivers, which are often amenable to estimation by the 'Gaussian Dispersion' type of models. However, a background air quality level should be prescribed to indicate the baseline air quality in the region of the project site, which would account for any pollution not covered by the two preceding contributions. The emission sources contributing to the background air quality would be located further afield and not easy to identify. In addition, the transport mechanism by which pollutants are carried over long distances (ranging from 1km up to tens or hundreds of kms) is rather complex and cannot be adequately estimated by the 'Gaussian' type of models.

3. Background Air Quality - Estimation Approach

3.1 The approach

In view of the difficulties in estimating background air quality using the air quality models currently available, an alternative approach based on monitored data is suggested. The essence of this approach is to adopt the long-term (5-year) averages of the most recent monitored air quality data obtained by EPD. These background data would be reviewed yearly or biennially depending on the availability of the monitored data. The approach is a first attempt to provide a reasonable estimate of the background air quality level for use in conjunction with EIA air quality assessment to address the cumulative impacts upon a locality. This approach may be replaced or supplemented by superior modelling efforts such as that entailed in PATH (Pollutants in the Atmosphere and their Transport over Hong Kong), a comprehensive territory-wide air quality modelling system currently being developed for Hong Kong. Notwithstanding this, the present approach is based on measured data and their long term regional averages; the background values so derived should therefore be indicative of the present background air quality. In the absence of any other meaningful way to estimate a background air quality for the future, this present background estimate should also be applied to future projects as a first attempt at a comprehensive estimate until a better approach is formulated.

3.2 Categorisation

The monitored air quality data, by 'district-averaging' are further divided into three categories, viz, Urban, Industrial and Rural/New Development. The background pollutant concentrations to be adopted for a project site would depend on the geographical constituency to which the site belongs. The categorisation of this constituency is the Rural/New Development category. The monitoring station suggested for the 'district-averaging'(arithmetic mean) to derive average for background air quality is Yuen Long.

The averaging would make use of data from the above stations wherever available. The majority of the monitoring stations are located some 20m above ground.

3.3 Background pollutant values

Based on the above approach, background value for TSP in rural/new development has been obtained as follow:

The unit is in micrograms per cubic metre. The above value is derived from 1992 to 1996 annual averages.

In cases where suitable air quality monitoring data representative of the study site such as those obtained from a nearby monitoring station or on-site sampling are not available for the prescription of background air pollution levels, the above tabulated value can be adopted instead. Strictly speaking, the suggested values are only appropriate for long term assessment. However, as an interim measure and until a better approach is formulated, the same value can also be used for short term assessment. This implies that the short term background value will be somewhat under-estimated, which compensates for the fact that some of the monitoring data are inherently influenced by secondary sources because of the monitoring station location.

Indeed, if good quality on-site sampling data which cover at least one year period are available, these can be used to derive both the long term (annual) and short term (daily / hourly) background values, the latter are usually applied on an hour to hour, day to day basis.

3.4 Provisions for 'double-counting'

The current approach is, by no means, a rigorous treatment of background air quality but aims to provide an as-realistic-as-possible approximation based on limited field data. 'Double-counting' of 'secondary contributions' may be apparent through the use of such 'monitoring-based' background data as some of the monitoring stations are of close proximity to existing emission sources. 'Primary contributions' due to a proposed project (which is yet to be realised) will not be double-counted by such an approach. In order to avoid over-estimation of background pollutant concentrations, an adjustment to the values given in section 3.3 is possible and optional by multiplying the following factor:

(1.0 - ESecondary contributions/ETerritory) where E stands for emission.

The significance of this factor is to eliminate the fractional contribution to background pollutant level of emissions due to 'secondary contributions' out of those from the entire territory. In most cases, this fractional contribution to background pollutant levels by the secondary contributions is minimal.

4. Conclusions

4.1 The above described approach to estimating the total air quality impacts of a proposed project, in particular the background pollutant concentrations for air quality assessment, should be adopted with immediate effect. Use of short term monitoring data to prescribe the background concentrations is no longer acceptable.

Modelling Section, Air Policy Group
Environmental Protection Department
March 2000

Appendix A-III

Guidelines on the Use of Alternative Computer Models in Air Quality Assessment

1. Background

1.1 In Hong Kong, a number of Gaussian plume models are commonly employed in regulatory applications such as application for specified process licences and environmental impact assessments (EIAs). These frequently used models (as listed in Schedule 1 attached; hereafter referred to as Schedule 1 models) have no regulatory status but form the basic set of tools for local-scale air quality assessment in Hong Kong.

1.2 However, no single model is sufficient to cover all situations encountered in regulatory applications. In order to ensure that the best model available is used for each regulatory application and that a model is not arbitrarily applied, the project proponent (and/or its environmental consultants) should assess the capabilities of various models available and adopt one that is most suitable for the project concerned.

1.3 Examples of situations where the use of an alternative model is warranted include:

(i) the complexity of the situation to be modelled far exceeds the capability of the Schedule 1 models; and

(ii) the performance of an alternative model is comparable or better than the Schedule1models.

1.4 This paper outlines the demonstration / submission required in order to support the use of an alternative air quality model for regulatory applications for Hong Kong.

2. Required Demonstration / Submission

2.1 Any model that is proposed for air quality applications and not listed amongst the Schedule 1 models will be considered by EPD on a case-by-case basis. In such cases, the proponent will have to provide the followings for EPD's review:

(i) Technical details of the proposed model; and
(ii) Performance evaluation of the proposed model

Based on the above information, EPD will determine the acceptability of the proposed model for a specific or general applications. The onus of providing adequate supporting materials rests entirely with the proponent.

2.2 To provide technical details of the proposed model, the proponent should submit documents containing at least the following information:

(i) mathematical formulation and data requirements of the model;
(ii) any previous performance evaluation of the model; and
(iii) a complete set of model input and output file(s) in commonly used electronic format.

2.3 On performance evaluation, the required approach and extent of demonstration varies depending on whether a Schedule 1 model is already available and suitable in simulating the situation under consideration. In cases where no Schedule 1 model is found applicable, the proponent must demonstrate that the proposed model passes the screening test as set out in USEPA Document "Protocol for Determining the Best Performing Model" (Ref. 1).

2.4 For cases where a Schedule 1 model is applicable to the project under consideration but an alternative model is proposed for use instead, the proponent must demonstrate either that

(i) the highest and second highest concentrations predicted by the proposed model are within 2 percent of the estimates obtained from an applicable Schedule 1 model (with appropriate options chosen) for all receptors for the project under consideration; or

(ii) the proposed model has superior performance against an applicable Schedule 1 model based on the evaluation procedure set out in USEPA Document "Protocol for Determining the Best Performing Model" (Ref. 1).

2.5 Should EPD find the information on technical details alone sufficient to indicate the acceptability of the proposed model, information on further performance evaluation as specified in Sections 2.3 and 2.4 above would not be necessary.

2.6 If the proposed model is an older version of one of the Schedule 1 models or was previously included in Schedule 1, the technical documents mentioned in Section 2.2 are normally not required. However, a performance demonstration of equivalence as stated in Section 2.4 (i) would become necessary.

2.7 If EPD is already in possession of some of the documents that describe the technical details of the proposed model, submission of the same by the proponent is not necessary. The proponent may check with EPD to avoid sending in duplicate information.

Modelling Section, Air Policy Group
Environmental Protection Department
March 2000

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

Ref. (1): William M. Cox, "Protocol for Determining the Best Performing Model" Publication No. EPA-454/R-92-025; U.S. Environmental Protection Agency, Research Triangle Park, NC.

* EPD is continually reviewing the latest development in air quality models and will update this Schedule accordingly.

Appendix B

Study Requirements of Cultural Heritage Impact Assessment

(1) Baseline Study

1.1 A baseline study shall be conducted:

a. to compile a comprehensive inventory of archaeological sites, historic buildings and structures which include:

b. to identify the direct and indirect impacts on the site of cultural heritage at the planning stage in order to avoid causing any negative effects. The impacts include the direct loss, destruction or disturbance of an element of cultural heritage, impact in its settings causing impinge on its character through inappropriate sitting or design, potential damage to the physical fabric of archaeological remains, historic buildings or historic landscapes through air pollution, change of water-table vibration, recreation pressure and ecological damage by the development. The impacts listed are merely to illustrate the range of potential impacts and not intended to be exhaustive.

1.2 The baseline study shall also include a desk-top study and a field survey.

1.3 Desk-top research

1.3.1 Desk-top researches should be conducted to analyse, collect and collate extant information. They include:

(a) Search of the list of declared monuments protected by the Antiquities and Monuments Ordinance (Chapter 53).

(b) Search of the list of deemed monuments through the Antiquities and Monuments Office (AMO) of the Leisure and Cultural Services Department.

(c) Search of the list of sites of cultural heritage identified by the AMO.

(d) Search of publications on local historical, architectural, anthropological, archaeological and other cultural studies, such as, Journals of the Royal Asiatic Society (Hong Kong Branch), Journals of Hong Kong Archaeological society, Antiquities and Monuments Office Monograph Series and so forth.

(e) Search of other unpublished papers, records, archival and historical documents through public libraries, archives, and the tertiary institutions, such as the Hong Kong Collection and libraries of the Department of Architecture of the University of Hong Kong and the Chinese University of Hong Kong, Public Records Office, photographic library of the Information Services Department and so forth.

(f) Search of any other unpublished archaeological investigation and excavation reports kept by the AMO.

(g) Search of historical documents in the Public Records Office, the Land Registry, District Lands Office, District Office and the Hong Kong Museum of History and so forth.

(h) Search of cartographic and pictorial documents. Maps of the recent past searched in the Maps and Aerial Photo Library of the Lands Department.

(i) Study of existing geotechnical information (for archaeological desk-top research)

(j) Discussion with local informants.

1.4 Field Evaluation

1.4.1 The potential value of the development site with regard to the cultural heritage could be established easily where the site is well-documented. However, it does not mean that the site is devoid of interest if it lacks information. In these instances, a site visit combined with discussions with appropriate individuals or organisations should be conducted by those with expertise in the area of cultural heritage to clarify the position.

1.4.2 Historic buildings and structures survey

(a) Field scan of all the historic buildings and structures within the project area.

(b) Photographic recording of each historic building or structure including the exterior (the elevations of all faces of the building premises, the roof, close up for the special architectural details) and the interior (special architectural details), if possible, as well as the surroundings of each historic building or structure.

(c) Conduct systematic auger survey/shovel testing to establish the horizontal spread of cultural materials deposits.

(d) Excavation of test pits to establish the vertical sequence of cultural materials. The hand digging of 1 x 1 m or 1.5 x 1.5 m test pits to determine the presence or absence of deeper archaeological deposits and their cultural history.

1.4.3 Archaeological Survey

The Archaeological Survey should be conducted by a qualified archaeologist who should apply for a Licence under the provision of the Antiquities and Monuments Ordinance (Cap.53).

Appropriate methods of field evaluation should be applied to assess the archaeological potential of the project area:

(a) Definition of areas of natural land undisturbed in the recent past.

(b) Field scan of the natural land undisturbed in the recent past in detail with special attention paid to areas of exposed soil which were searched for artifacts.

(c) Conduct systematic auger survey / shovel testing to establish the horizontal spread of cultural materials deposits.

1.4.4 If the field evaluation identifies any additional sites of cultural heritage within the study area which are of potential historic or archaeological importance and not recorded by AMO, the office should be reported as soon as possible. The historic and archaeological value of the items will be further assessed by the AMO.

1.5 The Report of Baseline Study

1.5.1 The study report should have concrete evidence to show that the process of the above desk-top and fields survey has been satisfactorily completed. This should take the form of a detailed inventory of the sites of cultural heritage supported by full description of their cultural significance. The description should contain detailed geographical, historical, archaeological, architectural, anthropological, ethnographic and other cultural data supplemented with illustrations below and photographic and cartographic records.

1.5.2 Historic Buildings and Structures

(a) A map in 1:1000 scale showing the boundary of each historic building or structure.

(b) Photographic records of each historic building or structure.

(c) Detailed record of each historic building or structure including its construction year, previous and present uses, architectural characteristics, as well as legends, historic persons and events, and cultural activities associated with the structure.

1.5.3 Archaeological Sites

(a) A map showing the boundary of each archaeological site as supported and delineated by field walking, augering and test-pitting.

(b) Drawing of stratigraphic section of test-pits excavated which shows the cultural sequence of a site.

1.5.4 A full bibliography and the source of information consulted should be provided to assist he evaluation of the quality of the evidence. It is expected that the study and result are up to an internationally accepted academic and professional standard.

(2) Impact Assessment

2.1 Cultural heritage impact assessment must be undertaken to identify the impacts of the sites of cultural heritage which will be affected by the proposed development subject to the result of desktop research and field evaluation. The prediction of impact and an evaluation of their significance must be undertaken by an expert in cultural heritage. During the assessment, both the direct impacts such as loss or damage of important features as well as indirect impacts such as change of water table levels which may affect the preservation of the archaeological and built heritage in situ should be stated. A detailed description and plans should be provided to elaborate to what extent the site of cultural heritage will be affected.

2.2 Preservation in totality must be taken as the first priority. Section 4.3.1(c), item 2 of Annex 10, items 2.6 to 2.9 of Annex 19 and other relevant parts of the Technical Memorandum on Environmental Impact Assessment Process shall be referred for the detailed requirements of the impact assessment.

(3) Mitigation Measures

3.1 It is always a good practice to recognize the site or monument early in the planning stage and site selection process, and to avoid it, i.e. preserve it in - situ, or leaving a buffer zone around the site. Built heritage, sites and landscapes are to be in favour of preservation unless it can be shown that there is a need for a particular development which is of paramount importance and outweighs the significance of the heritage feature.

3.2 If avoidance of the cultural heritage is not possible, amelioration can be achieved by reduction of the potential impacts and the preservation of heritage features, such as physical relocating it. Measures like amendments of the sitting, screening and revision of the detailed design of the development are required to lessen its degree of exposure if it causes visual intrusion to the cultural heritage and affecting its character.

3.3 All the assessment should be conducted by an expert in cultural heritage and further evaluated and endorsed by the Antiquities and Monuments Office and the Antiquities Advisory Board.

3.4 Besides referring to paragraph 4.3.1(d), items 2.10 to 2.14 of Annex 19 and other relevant parts of the Technical Memorandum, proposals for mitigation measures should be accompanied with a master layout plan together with all detailed treatment, elevations, and landscape plan. A rescue programme, when required, shall be proposed which may involve preservation of the historical building or structure together with the relics inside, and its historic environment through relocation, detailed cartographic and photographic survey or preservation of an archaeological site "by record", i.e. through excavation to extract the maximum data as the very last resort.

3.5 The programme for implementation of agreed mitigation measures should be able to be implemented, and clearly stated in the EIA report, as required in Annex 20 of the Technical Memorandum. In particular, item 6.7 of Annex 20 requires the Applicant to define and list out clearly the proposed mitigation measures to be implemented, by whom, when, where, to what requirements and the various implementation responsibilities. A comprehensive plan and programme for the protection and conservation of the partially preserved Site of Cultural Heritage, if any, during the planning and design stage of the proposed project must be details.