Harbour Area Treatment Scheme (HATS, formerly known as Strategic Sewage
Disposal Scheme) is to improve water quality in
Exhibit 1.1 Overall HATS Schematic Layout
1 involved the construction of a chemically enhanced primary treatment (CEPT)
sewage from the densely populated parts of Hong Kong Island (i.e., northern and
southwestern districts), which currently account for about 450,000 m3/d of sewage flow from the planned catchment of HATS, is only subject to
preliminary treatment (i.e., screening and de-gritting) before discharging into
the harbour. This preliminary treated
sewage, coupled with the un-disinfected effluent from the SCISTW, is a source
of the current water quality problems, particularly in the western part of the
harbour including bathing beaches in the Tsuen Wan area. Moreover, with the anticipated growth in
population and business activities in the harbour area, water quality would
resume a deteriorating trend in future unless the remainder
of untreated sewage
on recommendations of an earlier international review and
subsequent environmental and engineering feasibility studies,
and after taking into account the public’s views collected through a five-month
long consultation in 2004, the Government announced on 22nd April 2005 the
implementation of HATS Stage
1.5 Under Stage 2A (hereinafter referred to as the Project), the scope of work includes:
Upgrading of eight existing
preliminary treatment works (PTW) at North Point, Wan Chai East, Central,
· Extension of the deep tunnel network to collect and transfer sewage from the above preliminary treatment works to SCISTW for treatment and disposal
· Augmentation of the existing CEPT capacity at SCISTW from the present design capacity of 1.7million m3/day to the ultimate design capacity (which is estimated at about 2.45million m3/day based on latest available information)
· Provision of disinfection to all HATS effluent before discharging into the harbour
1.6 Under Stage 2B, a new secondary level (biological) treatment plant on a site adjacent to SCISTW is proposed to treat all HATS flow. Planning for Stage 2B is in hand, with a view to completing it in time to suit actual sewage flow build up and water quality conditions.
target for completing Stage
that the discharge of un-disinfected sewage effluent from SCISTW is
contributing to unsatisfactory beach water quality at the Tsuen Wan beaches,
the Government has also proposed to advance the provision of part of the
permanent disinfection facilities under HATS Stage
1.9 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 that take place concurrently. This information will contribute to decisions on:
· the overall acceptability of any adverse environmental consequences that are likely to arise as a result of the Project;
· the conditions and requirements for the detailed design, construction and operation of the Project to mitigate against adverse environmental consequences wherever practicable; and
· the acceptability of residual impacts after the proposed mitigation measures are implemented.
Project involves several types of Designated Projects under the Environmental
Impact Assessment Ordinance (EIAO) described in Table 1.1 and an Environmental Permit is required for its
construction and operation. On 17th
August 2005, the Environmental Protection Department (
Table 1.1 Designated Projects under the Environmental Impact Assessment Ordinance
Descriptions of Key Project Components
Item of the EIAO
Proposed Preliminary Treatment Works (PTWs) upgrading at North Point,
Wan Chai East, Central,
Item F1 Part I Schedule 2 of the EIAO
Proposed Stonecutters Island Sewage Treatment Works upgrading with an
installed capacity of more than
Item F1 Part I Schedule 2 of the EIAO
A deep tunnel from Central to
Item F5 Part I Schedule 2 of the EIAO
Proposed pumping stations at Cyberport, Sandy Bay, Wan Chai East, Ap Lei Chau, North Point and Aberdeen with an installed capacity more than 2,000m3 per day and a boundary of which are less than 150m from an existing or planned residential area, educational institution and/or health care institution
Item F3(b)(i) Part I Schedule 2 of the EIAO
Objectives of the Assignment
1.11 The main objective of the Assignment is to complete the EIA Study for the Project as required by the Study Brief in accordance with the EIAO. The EIA Report has been prepared to:
· describe the Project and associated works together with the requirements for carrying out the Project;
· identify and describe elements of community and environment to be affected by the Project and/or to cause adverse impacts to the Project, including both the natural and man-made environment and the associated environmental constraints;
· consider alternatives where necessary, with a view to avoiding and minimizing the potential environmental and ecological impacts, in particular, on sensitive receivers within the receiving water bodies; to compare the environmental benefits and dis-benefits of each of the different options; to provide reasons for selecting the preferred option(s) and to describe the part environmental factors played in the selection;
· identify and quantify emission sources and determine the significance of impacts on sensitive receivers and potential affected uses;
· identify and assess the level of disinfection required in order to protect the beneficial uses of the sensitive receivers identified, including the Tsuen Wan beaches;
· identify and quantify any potential losses or damage to flora, fauna and natural habitats;
· identify and quantify any potential landscape and visual impacts and to propose measures to mitigate these impacts;
· identify the negative impacts on any historical and archaeological resources and to propose measures to mitigate these impact;
· propose the provision of infrastructure or mitigation measures so as to minimize pollution, environmental disturbance and nuisance during construction and operation of the Project;
· investigate the feasibility, practicability, effectiveness and implications of the proposed mitigation measures;
· identify, predict and evaluate the residual (i.e. after practicable mitigation) environmental impacts 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;
· identify, assess and specify methods, measures and standards, to be included in the detailed design, construction and operation of the Project which are necessary to mitigate these environmental impacts and cumulative effects and reduce them to acceptable levels;
· 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
· design and specify the environmental monitoring and audit requirements to ensure the implementation and the effectiveness of the environmental protection and pollution control measures adopted.
1.12 The Assessment Area for the EIA Study, as specified in the Brief, includes:
Air quality impact assessment –
area within a distance of
Noise impact assessment – area
within a distance of
· Water quality impact assessment – cover the Water Control Zones of North Western, Western Buffer, Victoria Harbour, Eastern Buffer, Junk Bay and Southern, and it shall be extended to include major emission sources that may have a bearing on the environmental acceptability of the Project.
· Ecological impact assessment – area of terrestrial ecological assessment include all areas within 500m distance from the site boundary of the land-based works area of which the flora, fauna and other components of the ecological habitats are likely impacted by the Project such as the works at Sandy Bay, Cyberport, and Aberdeen. The assessment area of marine ecological assessment shall be the same as the assessment area for water-quality impact assessment, or the area likely to be impacted by the Project, including areas in the vicinity of the outfalls.
· Fisheries Impact assessment – generally the same as for water quality impact assessment, and any areas likely to be impacted by the Project, including the Ma Wan, Sok Kwu Wan, Lo Tik Wan, Cheung Sha Wan, Po Toi, and Tung Lung Chau fish culture zones.
· Landscape impact assessment – area within the sites and works areas due to the Project.
· Visual impact assessment – area within the Zone of Visual Influence (ZVIs) at construction and operation stages. These are the people who would reside within, work within, play within, or travel through, the ZVIs.
1.13 The structure of the EIA Report is set out below:
· Section 2 illustrates the Project locations, and provides a description of the Project highlighting the key elements and operation activities.
· Section 3 identifies and assesses the potential air quality impacts associated with the construction and operation of the Project.
· Section 4 identifies and assesses the potential air-borne noise impacts associated with the construction and operation of the Project.
· Section 5 identifies and assesses the potential ground-borne noise impacts associated with the construction of the Project.
· Section 6 identifies and assesses the potential water quality impacts associated with the construction and operation of the Project.
· Section 7 presents the human health risk assessment conducted for the operation of the Project.
· Section 8 presents the ecological risk assessment conducted for the operation of the Project.
· Section 9 evaluates and assesses the waste management implications associated with the construction and operation of the Project.
· Section 10 identifies and assesses the potential terrestrial ecological impacts associated with the construction and operation of the Project.
· Section 11 identifies and assesses the potential marine ecological impacts associated with the construction and operation of the Project.
· Section 12 identifies and assesses the potential impacts on fisheries resources associated with the construction and operation of the Project.
· Section 13 identifies and assesses the potential impacts on landscape and visual associated with construction and operation of the Project.
· Section 14 presents the hazard to life assessment conducted for the construction and operation of the Project.
· Section 15 identifies and assesses the potential impacts on cultural heritage associated with the construction and operation of the Project.
· Section 16 highlights the environmental monitoring and audit (EM&A) requirements for the Project. The scope and approach are presented in detail in a stand-alone EM&A Manual.
· Section 17 summarizes and concludes the findings of the EIA Study.
· Section 18 presents the Implementation Schedules for mitigation of the various environmental issues addressed in the EIA Study.
 In 2000, the Government commissioned an International Review Panel (IRP) to review the future of HATS. See http://www.cleanharbour.gov.hk/english/g3_2_1.html for details.
 The Environmental and Engineering Feasibility Assessment Studies for Further Stages of HATS (EEFS) was conducted over 2002 and 2003 to investigate and further conceptualise the IRP’s recommendations on implementing further stages of HATS. See http://www.cleanharbour.gov.hk/english/g3_2_1.html for details.
 The objective of the ADF is to reduce the E. coli level in the CEPT effluent at SCISTW prior to discharge and
hence facilitate early improvement to beach water quality. A separate EIA study - Agreement No. CE 7/2005 (EP) HATS EIA Study for the Provision of
Disinfection Facilities at Stonecutters Island