1 Introduction

1.1 Project Background

1.1.1.1 In the Policy Address 2015, the Government set out the intention to adopt the concept of revitalising water bodies in large-scale drainage improvement works and planning drainage networks for the new development areas. The concept of revitalising water bodies is aimed at promoting greening, biodiversity, beautification and water friendliness in addition to achieving efficient drainage, with a view to building sustainable drainage facilities and providing a better living environment.

1.1.1.2 Drainage Services Department (DSD) commissioned AECOM Asia Company Limited (AECOM) in December 2015 to undertake the feasibility study on “Study on Revitalisation of Water Bodies” under Agreement No. CE 28/2015 (DS). The Study identified during the process of selection that Fo Tan Nullah and Tai Wai Nullah are of high revitalisation potential and therefore were recommended for detailed investigation and proposing revitalisation schemes for implementation, taken into account their unique features and constraints.

1.1.1.3 In April 2020, AECOM was commissioned by DSD to undertake Agreement No. CE54/2019 (DS) – “Revitalisation of Tai Wai Nullah and Fo Tan Nullah – Investigation” (hereafter referred to as “the Assignment”) to revitalise the existing Tai Wai Nullah (TWN) and Fo Tan Nullah (FTN) with an aim to enhance their ecological value, provide a greener environment, promote water friendliness and improve the community environment. The Assignment also include provision of dry weather flow interceptors to improve the water quality. As part of the Assignment, an Environmental Impact Assessment (EIA) study under the Environmental Impact Assessment Ordinance (EIAO) is required for the proposed works to TWN and FTN, respectively. This EIA Report covers the EIA study for Revitalisation of TWN (hereafter referred to as “the Project”).

1.1.1.4 Consultants engaged by DSD will carry out the detailed design and construction supervision of the Project base on this EIA Report in the next stage of the Project. DSD will operate and maintain the completed works.

1.2 Designated Projects under EIAO

1.2.1.1 The proposed revitalisation of TWN is classified as designated project (DP) by virtue of Item I.1(b)(ii), Part I, Schedule 2 of the EIAO – “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 site of cultural heritage”.

1.2.1.2 Project Profile for Revitalisation of TWN (No. PP-586/2019) was submitted to the Environmental Protection Department (EPD) on 31 July 2019 for application for an EIA study brief under section 5(1)(a) of the EIAO. The EIA Study Brief for the Revitalisation of TWN (No. ESB-320/2019) was issued on 11 September 2019 under the EIAO .

1.3 Purpose of the EIA Study

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

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

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

1.4 Objectives of this EIA Study

1.4.1.1 The objectives of the EIA study as stated in the EIA Study Brief (No. ESB-320/2019) are as follows:

(a) to describe the Project and associated works together with the requirements and environmental benefits for carrying out the proposed Project;

(b) 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 and the associated environmental constraints;

(c) to provide information on the consideration of alternative options of the design, layout, scale and extent of the Project and the construction methods with a view to avoiding or minimising potential environmental impacts to environmentally sensitive areas and sensitive uses; to compare the environmental benefits and dis-benefits 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);

(d) to identify and quantify emission sources (including air quality, noise and water quality, etc. as appropriate) and determine the significance of impacts on sensitive receivers and potential affected uses;

(e) to identify and quantify potential waste management issues and impacts arising as a result of the construction and operation activities of the Project;

(f) to identify and quantify contaminated land within any project area for development works, and to propose measures to avoid disposal in the first instance;

(g) to identify, assess and quantify any potential ecological and fisheries impacts arising from the Project, including potential losses or damage to flora, fauna and natural habitats; and to propose measures to mitigate these impacts;

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

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

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

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

(l) 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;

(m) 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 residual environmental impacts and cumulative effects and reduce them to acceptable levels;

(n) to design and specify the environmental monitoring and audit requirements; and

(o) to identify any additional studies necessary to implement the mitigation measures of monitoring and proposals recommended in the EIA report.

1.5 Structure of the EIA Report

1.5.1.1 The background of the Project, purpose and objectives of this Report are introduced in this section. A description of the Project and details of options consideration are provided in Section 2. Sections 3 to 12 detail the results of the environmental impact assessment of each key subject area, covering relevant legislation, environmental conditions, assessment criteria, methodology, assessment findings and proposed mitigation measures.

1.5.1.2 Sections 3 to 12 are outlined as follows:

· Section 3: Air Quality Impact

· Section 4: Noise Impact

· Section 5: Water Quality Impact

· Section 6: Waste Management Implications

· Section 7: Land Contamination

· Section 8: Sewerage and Sewage Treatment Implications

· Section 9: Ecological Impact (Terrestrial and Marine)

· Section 10: Fisheries Impact

· Section 11: Cultural Heritage Impact

· Section 12: Landscape and Visual Impacts

1.5.1.3 An outline of the requirements for the Environmental Monitoring and Audit (EM&A) programme is presented in Section 13. The EM&A programme is presented in detail in a separate EM&A Manual. A detailed implementation schedule of the recommended mitigation measures is provided in Section 14. A summary of environmental outcomes and conclusions is presented in Section 15.