Environmental Impact  Assessment Ordinance (Cap. 499)

Section 5(7)

 

Environmental Impact Assessment Study Brief No. ESB-167/2007

 

 

Project Title :               Hang Hau Tsuen Channel at Lau Fau Shan

( hereinafter known as "the Project" )

 

Name of Applicant :     Civil Engineering and Development Department

                                     ( hereinafter known as "the Applicant")

 

 

1.         BACKGROUND

 

1.1                        An application (No. ESB-167/2007) for an Environmental Impact Assessment (EIA) study brief under section 5(1)(a) of the Environmental Impact Assessment Ordinance (EIAO) was submitted by the Applicant on 7 June 2007 with a Project Profile (No. PP-318/2007) for the Project.

 

1.2                        The Project is intended to alleviate the flooding problem in the area by converting the existing Hang Hau Tsuen stream between Deep Bay and Deep Bay Road into an engineered channel.  The proposed location and layout of the Project are shown in Figure 1.  The proposed project works comprise -

 

(i)                 training of Hang Hau Tsuen stream including construction of a drainage channel of 370m in length connecting the downstream ends of Fung Kong Tsuen Channel and San Hing Tsuen Channel to Deep Bay;

 

(ii)                construction of a25mbox culvert of 5.5m (w) x 3m (H) beneath the Deep Bay Road and 4 nos. of footbridges across the channel; and

 

(iii)              provision of an access road of 3.5 m in width with passing bays along the northern bank of the channel and footpaths of 2 m in width on both sides of the channel.

 

1.3                        The Project is a designated project by virtue of item I.1(b) (vi) of Schedule 2 of the EIAO.  In accordance with item I.1 (b) (vi), "A drainage channel or river training and diversion works which discharges or discharge into an area which is less than 300 m from the nearest boundary of an existing or planned coastal protection area" is a designated project.  In accordance with section 5(1)(a), a person who is planning a designated project shall apply to the Director for an environmental impact assessment study brief to proceed with an environmental impact assessment study for the project.

 

1.4            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.

 

1.5           The purpose of the EIA study is to provide information on the nature and extent of environmental impacts arising from the construction and operation of the Project and related activities 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 Project;

 

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

 

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

 

 

2.         OBJECTIVES OF THE EIA STUDY

 

2.1           The objectives of the EIA study are as follows -

 

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

 

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

 

(iii)       to provide information on consideration of alternatives to avoid and minimize potential environmental impacts to environmentally sensitive areas and other sensitive uses; to compare the environmental benefits and dis-benefits of each of different options; to provide reasons for selecting the preferred option(s) and to describe the part environmental factors played in the selection of preferred option(s);

 

(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 natural habitats and to propose measures to avoid or mitigate these impacts;

 

 

(vi)              to identify and quantify any potential landscape and visual impacts and determine the significance of impacts on sensitive receivers;

 

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

 

(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 and operation 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 and operation of the Project, which are necessary to mitigate these environmental impacts and reduce them to the acceptable levels;

 

(x)                to investigate the extent of 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, if required, to ensure the implementation and the effectiveness of the environmental protection and pollution control measures adopted.

 

 

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 for the EIA study.  The Applicant has to demonstrate in the EIA report that the criteria in the relevant sections of the Technical Memorandum on EIA Process of the EIAO (hereinafter referred to as the TM) are fully complied with.

 

3.2            The Scope

3.2.1         The scope of this EIA study covers the Project mentioned in section 1.2 above.  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 impact arising from the Project and associated activities on Hang Hau Tsuen stream and the coastal protection area in the vicinity, and the assessment shall include but not be limited to the stream course, stream meander, mangrove, inter-tidal mudflats and existing ponds within or near to Hang Hau Tsuen stream;

 

 

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

 

(iii)              the potential aquatic and terrestrial ecological impacts arising from the Project, including loss of habitats, removal of vegetation and disturbance to plants and animals.  The assessment shall fully address all direct, indirect and cumulative impacts arising from construction and operation of the Project on the integrity and viability of the ecosystems of Hang Hau Tsuen stream and Inner Deep Bay;

 

(iv)              the potential impacts arising from the Project on the drainage and hydrology, the water quality and aquatic ecology of Hang Hau Tsuen stream floodplain, in particular the potential impacts on the flow regime, water level and water quality on the stream meanders, mangrove, inter-tidal mudflat habitats and Inner Deep Bay; and

 

(v)               the potential landscape and visual impacts arising from the removal of stream meanders, vegetation cover, mangroves and mudflats and the cutting of bank(s) along channel sides.

 

 

3.3                        Consideration of Alternatives

Need for the Project

3.3.1         The Applicant shall provide information on the need for the Project and justification for the need and scale of the proposed works.  The Applicant shall explain clearly the purpose and objectives of the Project and describe the scenarios with and without the Project.

 

Consideration of Alternative Drainage Options, Channel Alignments and Designs

3.3.2         The Applicant shall identify feasible alternatives other than the proposed option presented in the Project Profile (No. PP-318/2007) to alleviate the flooding problem in the area.  In considering alternative flood alleviation options, channel alignments and lining designs, the Applicant shall take into account the need to minimize negative effects on Hang Hau Tsuen stream course, the mangrove colony, nearby fish pond habitats and the inter-tidal mudflats.

 

3.3.3         An evaluation system shall be set up to assess the environmental benefits and dis-benefits of all possible flood alleviation alternatives and channel design options.

 

 

 

 

Consideration of Alternative Construction Methods and Sequences of Works

3.3.4         Having regard to the cumulative effects of the construction period and the severity of the construction impacts to the affected sensitive receivers in the vicinity of the drainage channel, the EIA study shall also explore alternative construction methods and work sequences for the Project with a view to avoid adverse environmental impacts to the maximum practicable extent.  A comparison of the environmental benefits and dis-benefits of various construction methods shall be made.  The Applicant shall take into account the environmental implications of possible release of heavy metals from mud during excavation works and the potential water quality impact during the construction phase.

 

Need for Maintenance Dredging

3.3.5         The Applicant shall investigate any need for maintenance dredging during the operation stage.  If such a need is identified, the Applicant shall assess and quantify the frequency, the likely extent of maintenance dredging required and associated potential environmental impacts.

 

 

3.4            Technical Requirements

3.4.1         The Applicant shall conduct an EIA study to address all environmental aspects of the activities described in the scope set out in section 3.2 above subject to the findings of the evaluation process specified in section 3.3.  The EIA study shall be based on the best and latest information available during the course of the study.

 

3.4.2         The Applicant shall include in the EIA report details of the construction programme and methodologies.  The Applicant shall clearly state in the EIA report the time frame and work programmes of the Project and other concurrent projects, and assess the cumulative environmental impacts from the Project with all interacting projects, including staged implementation of the Project.

 

Use of Relevant Findings of Approved EIA Reports and Relevant Studies

3.4.3         The Applicant shall review all previously approved studies and EIA reports which are relevant to the Project and extract relevant information for the purpose of this study.

 

3.4.4         The EIA study shall include the following technical requirements on specific impacts.

 

 

 

 

 

3.4.5         Air Quality Impact

3.4.5.1      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.

 

Determination of Assessment Area

3.4.5.2           The area for air quality impact assessment shall be defined by a distance of 500m from the boundary of the Project works site, and may be extended depending on the circumstances and the scale of the Project.  The assessment shall include but not limited to the existing, planned and committed sensitive receivers within the assessment area.

 

3.4.5.3           The Applicant shall assess the air pollutant concentrations with reference to the relevant sections of the guidelines attached to this study brief in Appendices A-1 to A-3 or other methodology as agreed by the Director.

 

3.4.5.4           The air quality assessment shall be based on the best available information at the time of assessment.  The assessment shall include the following -