Environmental Impact Assessment Ordinance (Cap. 499),

Section 5(7)

Environmental Impact Assessment Study Brief No. ESB-133/2005

Project Title : LAMMA POWER STATION UNITS L4 & L5

FLUE GAS DESULPHURIZATION PLANT RETROFIT PROJECT

(hereinafter known as the "Project")

Name of Applicant : THE HONGKONG ELECTRIC CO., LTD.

(hereinafter known as the "Applicant")

1. BACKGROUND

1.1 An application (No. ESB-133/2005) 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 21 September 2005 with a Project Profile (No. PP-261/2005) (the Project Profile).

1.2 The proposed Project is to retrofit two existing 350MW coal-fired generating units, namely L4 and L5, of the Lamma Power Station with Flue Gas Desulphurization (FGD) plant for reducing the overall sulphur dioxide emission from the Lamma Power Station. It is proposed to adopt the “Wet Limestone- Gypsum” process for the FGD plants. Location of the Project is given in the Figure No. 2.4a of the Project Profile and is reproduced in Appendix A.

1.3 The scope of the Project includes the following major works:

- Installation of FGD plants with FGD efficiency of 90% for the two 350MW coal-fired Units L4 and L5 by adding the followings equipments :

s Two sets of FGD absorbers and associated ductworks;

s Two sets of booster fans;

s Two sets of gas-gas heaters;

s FGD Switchgear and Equipment Building; and

s Gypsum dewatering system comprising two sets of hydrocyclones and belt filters; and

- Demolition of the existing Numbers 4 and 5 Light Oil Tanks, each of 250m³ capacity, and relocation of some pipeworks to provide areas for the installation of FGD plants.

1.4 The Project is a material change to an exempted designated project, the Lamma Power Station as a Public Utility Electricity Power Plant (Item D.1 Part I Schedule 2 of the EIAO), under the EIAO because of the changes induced by the FGD operations to the types and quantities of emissions, wastes and effluents. In addition, the demolition of two existing Light Oil Tanks is a designated project under item 16 Part II (Decommissioning Projects) Schedule 2 of the EIAO (i.e. A store for oil with a storage capacity exceeding 200 tonnes).

1.5 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.

1.6 The purpose of this EIA study is to provide information on the nature and extent of environmental impacts arising from the construction, operation and decommissioning 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 is to arise as a result of the Project and the associated activities of the Project;

(ii) the conditions and requirements for the detailed design, construction, operation and decommissioning of the Project to mitigate against adverse environmental consequences; 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 and environmental benefits for carrying out the Project;

(ii) to identify if there are other types of Designated Projects under Schedule 2 of the EIAO to be covered in the Project;

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

(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 land contamination caused, to determine the significance of the impact and to propose measures to mitigate the impact;

(vi) to propose the provision of infrastructure or mitigation measures to minimize pollution, environmental disturbance and nuisance during construction, operation and decommissioning of the Project;

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

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

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

(x) 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

(xi) to design and specify the 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 and to specify the environmental issues that are required to be reviewed and assessed in the EIA report. 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 met.

3.2 The Scope

The scope of this EIA study shall cover the Project proposed in the Project Profile and shall include the works and facilities mentioned in Sections 1.2 and 1.3 above. The EIA study shall address the key issues described below, together with any other key issues identified during the course of the EIA study and the cumulative environmental impacts of the Project, through interaction or in combination with other existing, committed, planned and known potential developments in the vicinity of the Project:

(i) the hazards and environmental impacts associated with the potential land contamination arising from demolition of the two existing Numbers 4 and 5 Light Oil Tanks, and the secondary hazards and environmental impacts that may arise from remediation of contaminated land;

(ii) the potential air quality impacts, both positive and negative, caused by the FGD plants during operation of the Project; and

(iii) the potential water quality impact and waste management implication caused by the FGD plants during operation of the Project.

3.3 Consideration of Alternatives

3.3.1 Need for the Project

The Applicant shall present in the EIA the information on the need for and the environmental benefits of the Project and the Project’s implementation programme.

3.3.3 Consideration of Alternative Construction/Decontamination Methods

Having regard to the findings of the land contamination assessment, the EIA study shall explore alternative construction/decontamination methods for the Project, with a view to avoiding hazards and adverse environmental impacts to the maximum practicable extent. A comparison of the environmental benefits and dis-benefits of applying different construction/decontamination methods shall be made with a view to recommending the preferred methods to avoid adverse on-site and off-site environmental impact to the maximum practicable extent.

3.4 Technical Requirements

The Applicant shall conduct the EIA study to address the environmental aspects as described in Sections 3.1, 3.2 and 3.3 above. The assessment shall be based on the best and latest information available during the course of the EIA study. The Applicant shall assess the cumulative environmental impacts from the Project with other interacting projects. The Applicant shall include in the EIA report details of the construction and decommissioning programme and methodologies.

The Applicant shall review previously studies or EIA reports which are relevant to the Project and extract relevant information for the purpose of this EIA study. The following studies or EIA reports shall be referred to :

- Environmental Impact Assessment of Units L7 and L8 Lamma Power Station (EIAO Register No. EIA-012/BC);

- Environmental Impact Assessment of a 1,800MW Gas-Fired Power Station at Lamma Extension (EIAO Register No. AEIAR-010/1999); and

- Project Profile - Lamma Power Station Conversion of Two Existing Gas Turbines (GT5 and GT7) into a Combined Cycle Unit (EIAO Register No. PP-093/2000)

The EIA study shall meet the following technical requirements on specific impacts, unless otherwise approved by the Director specifically in writing.

3.4.1 Land Contamination

3.4.1.1 The Applicant shall follow the guidelines as stated in Sections 3.1 and 3.2 of Annex 19 in the TM for evaluation and assessing potential land contamination issues due to the demolition of the existing Light Oil Tanks and the relocation of pipeworks of the Project, as stipulated in Section 1.3 above.

3.4.1.2 The Applicant shall provide a clear and detailed account of the present land use (including description of the activities, chemicals and hazardous substances handled with clear indication of their storage and location by reference to a site layout plan), the relevant past land use history in relation to possible land contamination (e.g. accident records, etc.) and the presence of any contaminated materials.

3.4.1.3 The Applicant shall submit a contamination assessment plan (CAP) to the Director for agreement prior to conducting a contamination assessment of the site. The CAP shall include proposals on sampling and analysis required and shall aim at determining the nature and extent of the contamination of the site.

3.4.1.4 Based on the agreed CAP, the Applicant shall conduct a land contamination assessment and compile a Contamination Assessment Report (CAR) to document the findings and to confirm whether the site is contaminated or not. If land contamination is confirmed, a remediation action plan (RAP) shall be prepared to formulate in detail any necessary remedial measures for management of the contaminated soil and materials.

3.4.1.5 The field investigation and sampling work should be conducted in a safe and proper manner and the RAP shall provide necessary measures for ensuring that the contaminated soil and materials will be handled and managed in a safe and proper manner.

3.4.1.6 The Applicant shall prepare the CAP, CAR and, if necessary, the RAP in accordance with ProPECC Practice Note No. 3/94 “Contaminated Land Assessment and Remediation” and other relevant guidance notes.

3.4.1.7 The Applicant shall address any hazards and environmental impacts associated with the potential land contamination, if confirmed, and the secondary hazards and environmental impacts that may arise from remediation and disposal of contaminated soil and materials. The assumptions, methodology, data, findings, recommendations and conclusions of CAP, CAR and, if necessary, the RAP shall be included in the EIA report.

3.4.2 Air Quality Impact

3.4.2.1 The Applicant shall follow the criteria and guidelines as stated in Section 1 of Annex 4 and Annex 12 of the TM for evaluating and assessing the air quality impact due to the operation of the Project, as stipulated in Sections 1.2 and 1.3 above.

3.4.2.2 As stipulated in Section 1.2 above, the Project is for reducing the overall sulphur dioxide emission from the Lamma Power Station. The Applicant may carry out a comparative study to demonstrate if the stack emission impacts of the coal-fired Units L4 & L5 before and after the Project will lead to lower air quality impacts at the Air Sensitive Receivers (ASRs) including the areas of Lamma Island, Cheung Chau as well as Southern District and Central & Western District of Hong Kong Island by using either a simple screening tool such as ISCST3 Gaussian model or a more sophisticated tool, such as wind tunnel test, if necessary. If result of the comparative study shows that the air quality impacts at ASRs are worsened, the air quality impact assessment following the technical requirements as described in Section 3.4.2.5 below shall be carried out to evaluate the cumulative impacts at the identified ASRs against the criteria set out in section 1 of Annex 4 of the TM. The cumulative assessment for the stack emission impact shall take into account the project specific impacts together with a regional-wide emission impact for background concentration.

3.4.2.3 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, and it shall be extended to include other areas that may have a bearing on the environmental acceptability of the Project. For this Project, the assessment shall include the existing and planned/committed air sensitive receivers within the study area, areas of Lamma Island, Cheung Chau as well as Southern District and Central & Western District of Hong Kong Island where the air quality may be potentially affected by the Project. Such assessment shall be based on the best available information at the time of the assessment.

3.4.2.4 The Applicant shall assess the air pollutant concentrations with reference to the Guidelines for Local-Scale Air Quality Assessment Using Models given in Appendices B1 – B3 or other methodology as agreed by the Director.

3.4.2.5 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 operation stage.

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

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

(a) Identify and describe representative existing and planned/committed ASRs that would 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 such that they represent the worst impact point of these ASRs. A map showing the location and description including name of buildings, their uses 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.

(b) Provide an exhaustive list of air pollutant emission sources within the Lamma Power Station which are to have impact related to the Project based on the analysis of the operational activities in Section 3.4.2.5(i) above. Apart from stack emissions, it is also necessary to address any air quality issue due to additional marine traffic emissions for transportation of materials including limestone and gypsum. Besides, if the likely concurrent projects are identified relevant, its possible emissions shall also be taken into account in the air quality impact assessment. Confirmation of the validity of the assumptions and the magnitude of the activities shall be obtained from the relevant parties and documented.

(iii) Operational Phase Air Quality Impact

(a) The Applicant shall assess the expected air pollutants, including gaseous emissions and dust, 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 Section 3.4.2.5(ii)(b) above. The Applicant shall follow the methodology as described in Section 3.4.2.5 (iv) below when carrying out the quantitative assessment.

(iv) Quantitative Assessment Methodology

(a) In choosing the types of models (such as physical or numerical) to be used for quantitative assessment of the operational phase air quality impact, the Applicant shall apply the general principles enunciated in the modelling guidelines in Appendices B-1 to B-3 while making allowance for the specific characteristics of the Project. The 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 into the modelling shall be presented in the EIA report. The Applicant must ensure consistency between the text description and the model files. 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) If the predicted air quality impacts at the ASRs are worsened by the Project, the Applicant shall calculate the cumulative air pollutant concentrations at the identified ASRs identified under Section 3.4.2.5(ii) above 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 as appropriate, to be evaluated against the relevant air quality standards and on any effect they may have on the land use implications. If applicable, plans of a suitable scale should be used to present pollution contour to allow buffer distance requirements to be determined properly.

(v) 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. If these measures will result in any constraints on future land use planning outside the project site, the Applicant shall liaise with the relevant government departments/authorities and document the agreement in the EIA Report in order to demonstrate that the proposed measures are feasible and practicable. The Applicant shall demonstrate quantitatively that the residual 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

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

3.4.3 Water Quality Impact

3.4.3.1 The Applicant shall follow the criteria and guidelines as stated in Annexes 6 and 14 of the TM for evaluating and assessing water quality impacts arising from the the Project.

3.4.3.2 The study area for this water quality assessment shall cover the Southern Water Control Zone (as shown in Appendix C) as designated under the Water Pollution Control Ordinance (WPCO). This study area could be extended to include other areas 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 analyse physical, chemical and biological disruptions of marine, fresh water or ground water system(s), catchment area(s), storm water pipeline, submarine outfalls, and coastal water arising during construction and operation of the Project. The water quality impact assessment shall cover major aspects of concern which include impacts of demolition and relocation of existing facilities with reference to the findings of the Land Contamination Assessment in Section 3.4.1 above and impacts of wastewater and effluent treatment and disposal during operational stage of the Project.

3.4.3.4 The Applicant shall include the following in the water quality impact assessment :

i) collection and review of background information on the existing and planned water system(s) and the respective catchment(s) and sensitive receivers which might be affected by the Project. Characterization of water and sediment quality of those affected or potentially affected areas based on the collected information or site surveys and tests as appropriate;

ii) identification and analysis of existing and planned future activities and beneficial uses related to the water system(s) and identification of water sensitive receivers;

iii) Establishment of pertinent water and sediment quality objectives, criteria and standards for the water system(s) and sensitive receivers in Sections 3.4.3.4 (i) and (ii) above;

iv) identification, analysis and quantification of existing and likely future water and sediment pollution sources and loading, including point discharges and non-point sources to surface water runoff, spent industrial wastewater from the Project and other process wastewater. If appropriate, field investigation and laboratory tests shall be conducted. An emission inventory on the quantities and characteristics of all these pollution sources shall be provided;

v) analysis of the provision and adequacy of existing wastewater treatment plants and sewerage infrastructure and wastewater management practices to treat and dispose of the wastewater identified in Section 3.4.3.4 (iv) above;

vi) assessment of the cumulative impacts due to other related concurrent and planned projects, activities or pollution sources within the Lamma Power Station;

vii) proposals for upgrading or providing any effective infrastructure, water pollution prevention and mitigation measures to be implemented during the construction and operational stages so as to avoid and reduce the water and sediment quality impacts, and to rectify any deficiencies and potential problems as may be identified in Sections 3.4.3.4 (v) and (vi) above, to within acceptable standards. Requirements to be incorporated in the Project’s contract document shall also be proposed. Best management practices to reduce storm water and non-point source pollution shall be investigated and proposed as appropriate; and

viii) evaluation and quantification of residual impacts on the water system(s) and the sensitive receivers with regard to the appropriate water and sediment quality objectives, criteria and standards established in Section 3.4.3.4 (iii) above.

3.4.4 Waste Management Implications

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

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 and chemical waste arising as a result of the construction and operation activities of the Project.

(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 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 considered. Gypsum, the solid by-product arising from the operation of the Project, shall be reused e.g. in cement manufacturing, wallboard production, etc;

(b) After considering 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 the wastes shall be described in detail. The disposal options recommended for each type of wastes shall take into account the result of the assessment in item (c) below; and

(c) The impact caused by handling (including stockpiling, labelling, packaging & storage), collection, transportation 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; and

- wastewater discharge, if any.

3.4.5 Noise Impact

3.4.5.1 The Applicant shall follow the criteria and guidelines as stated in Annexes 5 and 13 of the TM for evaluating and addressing the noise impacts arising from the operational stage of the Project.

3.4.5.2 As stipulated in Section 1.3 above, the Project involves equipments of much smaller quantities and sizes as compared with other existing equipments in the Lamma Power Station. It is envisaged that the Project will have insignificant contribution to the cumulative operational noise of the Lamma Power Station. The Applicant shall assess the expected operational noise arising from the Project using standard acoustics principle and compare against the criteria set out in Table 1A of Annex 5 of the TM. The Applicant shall propose direct technical remedies within the project limits in situations where the predicted noise level exceeds the criteria set out in Table 1A of Annex 5 of the TM.

3.4.6 Construction Phase Air Quality and Noise Impacts

3.4.6.1 The Applicant shall follow the requirements stipulated under the Air Pollution Control (Construction Dust) Regulation to ensure that construction dust which may arise as a result of construction works are controlled within the relevant standards as stipulated in Section 1 of Annex 4 of the TM.

3.4.6.1 The Applicant shall propose the good site practices and/or any other mitigation measures to ensure that construction noise which may arise as a result of construction works are controlled within the relevant objectives, criteria, standards or guidelines.

3.4.7 Visual Illustration

3.4.7.1 The Applicant shall provide layout plans, elevations, sections in appropriate scale and with dimensions, perspective drawings and photomontages to show the form, appearance and colour scheme of the Project representative viewpoints.

3.4.8 Summary of Environmental Outcomes

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

3.4.9 Environmental Monitoring and Audit (EM&A) Requirements

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

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

3.4.9.3 The Applicant shall prepare a project implementation schedule (in the form of a checklist as shown in Appendix D to this EIA study brief) containing 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 36 months from 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 above documents available to the public, subject to payment by the interested parties of full costs of printing.

5.4 In addition, to facilitate 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 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 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 Sections 1.2 and 1.3 of this EIA study brief and in Project Profile (No. PP-261/2005), 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 ---

October 2005

Environmental Assessment Division

Environmental Protection Department

Appendix A

Appendix B-1

Guidelines on Choice of Models and Model Parameters

[The information contained in this Appendix is only meant to assist the Applicant in performing the air quality assessment. The Applicant must exercise professional judgment in applying this general information for the Project.]

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 modelling exercise 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 models can be used to estimate the near-field impacts of a number of source types including dust, traffic and industrial emissions.

Model Applications

FDM for evaluating fugitive and open dust source impacts (point, line and area sources)

CALINE4 for evaluating mobile traffic emission impacts (line sources)

ISCST3 for evaluating industrial chimney releases as well as area and volumetric sources (point, area and volume sources); line sources can be approximated by a number of volume sources.

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 Section 3) and assumptions, allow direct comparison with the relevant air quality appropriate model parameters (refer to 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 10^o) 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, σ_Θ, needs to be provided as input to the CALINE4 model. Typical values ofσ_Θ range from 12^o for rural areas to 24^o for highly urbanised areas under 'D' class stability. For semi-rural such as new development areas, 18^o 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, 5^th Edition, 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 NO_x Ratio

The conversion of NO_x 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 NO_x 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 NO_x 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 EPD reference paper 'Guidelines on Assessing the 'TOTAL' Air Quality Impacts' in Appendix B-2).

3.8 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:

Stability Category 1-hour to 5-sec Conversion Factor

A & B 45

C 27

D 9

E & F 8

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.

3.9 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.

3.10 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. 5, 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. 6) or any other suitable models subject to prior agreement with EPD. The EPD’s 'Guidelines on the Use of Alternative Computer Models in Air Quality Assessment' should also be referred to in Appendix B-3.

Ref.(5): XIXth World Road Congress Report, Permanent International Association of Road Congresses (PIARC), 1991.

Ref.(6): 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

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

Appendix B-2

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:

Primary contributions: project induced

Secondary contributions: pollutant-emitting activities in the immediate neighbourhood

Other contributions: pollution not accounted for by the previous two

(Background contributions)

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 these constituencies is given in Section 3.4. The monitoring stations suggested for the 'district-averaging'(arithmetic means) to derive averages for the three background air quality categories are listed as follows:

Urban: Kwun Tong, Sham Shui Po, Tsim Sha Tsui and Central/Western

Industrial: Kwun Tong, Tsuen Wan and Kwai Chung

Rural/New Development: Sha Tin, Tai Po, Junk Bay, Hong Kong South and 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 values for the 3 categories have been obtained for a few major air pollutants as follows:

POLLUTANT	URBAN	INDUSTRIAL	RURAL / NEW DEVELOPMENT
NO₂	59	57	39
SO₂	21	26	13
O₃	62	68	57
TSP	98	96	87
RSP	60	58	51

All units are in micrograms per cubic metre. The above values are derived from 1992 to 1996 annual averages with the exception of ozone which represent annual average of daily hourly maximum values for year 1996.

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 values 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 values can also be used for short term assessment. This implies that the short term background values 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 Site categories

The categories to which the 19 geographical constituencies belong are listed as follows:

DISTRICT	AIR QUALITY CATEGORY
Islands	Rural / New Development
Southern	Rural / New Development
Eastern	Urban
Wan Chai	Urban
Central & Western	Urban
Sai Kung	Rural / New Development
Kwun Tong	Industrial
Wong Tai Sin	Urban
Kowloon City	Urban
Yau Tsim	Urban
Mong Kok	Urban
Sham Shui Po	Urban
Kwai Tsing	Industrial
Sha Tin	Rural / New Development
Tsuen Wan	Industrial
Tuen Mun	Rural / New Development
Tai Po	Rural / New Development
Yuen Long	Rural / New Development
Northern	Rural / New Development

3.5 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 realized) 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 - E_{Secondary contributions}/E_Territory)

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.

Appendix B-3

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 Schedule 1 models.

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.

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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

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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 C

Appendix D

Implementation Schedule

EIA Ref.	EM&A Ref.	Recommended Mitigation Measures	Objectives of the Recommended Measure & Main Concerns to address	Who to implement the measure ?	Location of the measure	When to implement the measure ?	What requirements or standards for the measure to achieve ?