1.1.1
The existing Yuen Long Town Nullah (YLTN) was
constructed in mid 1960s to alleviate the flooding risks in the Northwest New
Territories and is one of the oldest drainage systems in Hong Kong. Most of the nullah sections were originally
natural water courses, which have been straightened and modified. The nullahs now primarily consist of
channelized concrete bedding and embankments.
1.1.2
With the increasing aspirations for a better living environment,
the local residents of Yuen Long are requesting the
Government to improve the early design of the YLTN, which is considered no
longer in line with the changing townscape of Yuen Long. In addition, odour from the nullah due to the
polluted dry weather flow is causing nuisance to the nearby residents.
1.1.3
In January 2007, the Drainage Services Department
(DSD) of
the Government of the Hong Kong Special Administrative Region (HKSARG) commissioned Black
& Veatch Hong Kong Limited (B&V) to carry out a feasibility study on “Rehabilitation of Yuen
Long Town Nullahs” to investigate various options for improving the design and environmental
conditions of the YLTN. The Study
recommended intercepting the polluted dry weather flow to the nullah for
treatment in the existing Yuen Long Sewage Treatment Works (YLSTW) to alleviate
the odour nuisance. The Study also recommended
landscaping works to be undertaken along the nullah for beautification purpose
in order to bring beneficial landscape and visual impacts.
1.1.4
In relation to the findings of the feasibility
study, B&V was further commissioned by DSD in August 2010 to
conduct “Agreement No. CE 6/2010 – Improvement of Yuen Long Town Nullah (Town
Centre Section) – Investigation” to investigate the improvement and
beautification of the town center section of YLTN between On Lok Road and Ma
Tong Road of Yuen Long.
1.1.5 In December 2012, B&V was commissioned by DSD to undertake the detailed design and construction supervision of Improvement of YLTN (Town Centre Section) – Stage 1 Improvement Works. In view of the latest development of the YLTN, the landscaping works and beautification has been recommended to be implemented under another DSD’s project “Yuen Long Barrage Scheme – Investigation, Design and Construction” which will be covered in a separated Environmental Impact Assessment (EIA) study. According to the hydraulic analysis of YLTN, the landscaping and beautification works inside the nullah could only be constructed after the implementation of the Barrage Scheme due to adverse hydraulic impact would be induced by the works. Such arrangement has been discussed and agreed with DSD and the project team of the Barrage Scheme and this arrangement would further provide the opportunity to explore alternative landscaping and beautification schemes after the water level in YLTN has been greatly drawn down by the Barrage Scheme. This project will not preempt the future design and the beautification works/environmental enhancement measures of the Barrage Scheme. The size of the DWF interceptors would be optimized and reduced to allow flexibility of the beautification works. Close liaison with the design team of Barrage Scheme is also being carried out.
1.1.6 According to the latest design, the Project mainly comprises provision of a dry weather flow interception (DWFI) system, including construction of dry weather flow (DWF) interceptors, interception u-channel/pipe along the Town Centre Section of YLTN and a new pumping station with an average capacity of approximately 18,000 m3/day. The general location plan of the Project is shown in Figure 1.1.
1.2.1 A Project Profile (PP-485/2013) was submitted to the Director of Environmental Protection (DEP) on 7 March 2013. The DEP issued an EIA Study Brief (ESB-260/2013) on 3 April 2013 for this EIA Study.
1.3.1
The overall objectives of the EIA Study are:
·
to provide information on the nature and extent of
environmental impacts arising from the construction and operation of the Project
and the related activities taking place concurrently;
·
to recommend appropriate mitigation measures to control the
potential environmental impacts so that it complies with the requirements of
the ‘Technical Memorandum on Environmental Impact Assessment Process’
(EIAO-TM); and
·
to confirm the environmental acceptability of the Project.
1.3.2
The specific objectives of the EIA Study described in the EIA
Study Brief (No. ESB-260/2013) are listed below:
(i)
to describe the Project and associated works together with
the requirements and environmental benefits for carrying out the Project;
(ii)
to identify and describe elements of 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;
(iii)
to identify and quantify emission sources and determine the
significance of impacts on sensitive receivers and potential affected uses;
(iv)
to identify and quantify any potential losses or damage to
flora, fauna and wildlife habitats;
(v)
to identify and evaluate any potential landscape and visual
impacts and to propose measures to mitigate these impacts;
(vi)
to propose the provision of infrastructure or mitigation
measures to minimize pollution, environmental disturbance and nuisance during
the construction and operation of the Project;
(vii)
to investigate the feasibility, effectiveness and implication
of the proposed mitigation measures;
(viii)
to 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 potentially 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 residual environmental
impacts and cumulative effects and reduce them to acceptable levels;
(x)
to design and specify environmental monitoring and audit
requirements; and
(xi)
to identify any additional studies necessary to implement the
mitigation measures or monitoring and proposals recommended in the EIA report.
1.4.1
The remainder of this EIA report is organised as follows:
·
Section 2 presents
a description of the Project;
·
Section 3 presents
a description of the alternatives considered for the design and construction of
the Project;
·
Section 4 presents
the air quality impact assessment;
·
Section 5 presents
the noise impact assessment;
·
Section 6 presents
the water quality impact assessment;
·
Section 7 presents
the waste management implication and land contamination assessment;
·
Section 8 presents
the ecological impact assessment;
·
Section 9 presents
the landscape and visual impact assessment;
·
Section 10 describes the
requirements for environmental monitoring and audit; and
·
Section 11 summarises
the environmental outcomes associated with the Project.