ykt water treatment works (phi)

8/2/2019 YKT Water Treatment Works (PHI)

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ENVIRONMENTAL IMPACT ASSESSMENT ORDINANCE (CAP 499)

S.5(1)(a)

PROJECT PROFILE

FOR

DESIGNATED PROJECT

ON

TSUEN WAN BYPASS, WIDENING OF TSUEN WAN ROAD BETWEEN

TSUEN TSING INTERCHANGE AND KWAI TSING INTERCHANGE, AND

ASSOCIATED JUNCTION IMPROVEMENT WORKS


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1.

BASIC INFORMATION

1.1 Project TitleThe project was formerly known as Tsuen Wan Road Upgrading. In

order to more clearly reflect the scope of the project, the project has been

renamed as Tsuen Wan Bypass, Widening of Tsuen Wan Road between

Tsuen Tsing Interchange and Kwai Tsing Interchange and associatedJunction Improvement Works. Tsuen Wan Bypass refers to the proposed

viaducts between Tuen Mun Road and Tsuen Tsing Interchange.

1.2 Purpose and Nature of the ProjectTsuen Wan Road (TWR) (see attached Drg. No. NTW Z1301) is part of the

strategic road network carrying a significant volume of long distance traffic

through the Tsuen Wan area, between the north-west New Territories,

Kowloon and Hong Kong Island. It also functions as a

collector-distributor road in Tsuen Wan.

According to Strategic Highway Project Review Report No. 6/2004 issued

by Transport Department in November 2004, the existing TWR is very well

utilized with a peak V/C ratio of 1.0. Congestion is normally caused by

tailback from the existing interchanges and is most frequent at Tai Chung

Road Interchange, causing occasional blockage to the through traffic.

The situation is worsened by the presence of heavy weaving movements

along TWR which cause interruptions to the smooth running of the through

traffic. The additional lanes would provide the necessary capacity for the

through traffic on TWR.


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1.4

Location and Scale of Project and History of SiteAttached Drg. No. NTW Z1301 shows the general layout of the project.

History of the Site

The geology along the corridor comprises a bedrock formation of fine to

coarse grained granodiorite with intrusion of medium to coarse grainedgranite in the vicinity of Kwai Chung Park area. The rockhead has a depth

of less than 45mm below the existing ground level in general. Rockhead

appears very close to the existing ground in the vicinity of Tsuen Tsing

Interchange.

The thickness of completely or highly decomposed rock overlying the

bedrock varies from 1m to 20m along the route, but generally in the range

of 5m to 15m.

Existing drillhole records indicate that the proposed alignment is sited

generally on reclaimed land apart from the vicinity of Tsuen Tsing

Interchange which was previously high ground and has been cut during the

site formation. The distribution of marine deposits and alluvium along the

alignment indicate that the marine deposits and alluvium were dredged

before the reclamation. However, thin layers of marine deposits and

alluvium (up to 4m thick) overlying completely decomposed granodiorite

are present in the vicinity of Hoi Hing Road near Hoi Kok Street. A layer

of marine deposits up to 4m thick is also present adjacent to the Kwai

Chung Park area.

The site along the proposed alignment is formed of fill of thickness up to


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Under the project, two single lane viaducts with connection to Tuen MunRoad will be provided on the two sides of the existing elevated section of

TWR. The proposed viaducts will be separate from the existing structure.

Near Hoi Kok Street, these two single lane viaducts will link with the up

and down ramps from/to Hoi On Road and become two 2-lane viaducts.

The proposed 2-lane viaducts will also be separate from the existing

structure and located on the two sides of the existing elevated section ofTWR. A down ramp branching off from the Kowloon bound 2-lane

viaduct would be provided near Tsuen Tsing Interchange for the traffic to

Texaco Road. The proposed 2-lane viaducts will end after joining the

at-grade TWR near Tsuen Tsing Interchange, where the existing at-grade

TWR would be widened from dual-3 to dual-5 until the Project limit near

Kwai Tsing Interchange.

Under the former project scope, a tunnel providing a bypass to the Castle

Peak Road traffic would be constructed near Hoi On Road as part of the

Tsuen Wan Bay Further Reclamation (TWBFR) to join the new viaducts

parallel to the existing TWR. With the absence of TWBFR, this bypass

would not be provided. As such, a new project profile is submitted for the

revised project scope.

The proposed scope of the project is thus as follows:

construction of dual one-lane viaducts parallel to the existing TWRbetween Tuen Mun Road and Hoi Kok street;

construction of dual 2-lane viaducts parallel to the existing TWRbetween Hoi Kok Street and Tsuen Tsing Interchange;

widening of the existing at grade section of TWR from dual 3-lane todual 5-lane between Tsuen Tsing Interchange and Kwai Tsing


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1.5

Number and Types of Designated Projects

The following items are identified as Designed Project under the items A.1

in Schedule 2 of the Environmental Impact Assessment (EIA) Ordinance

(Cap. 499).

Proposed dual-one lane viaducts running parallel to the existing TWRbetween Tuen Mun Road and Hoi Kok Street;

Proposed dual-two lane viaducts running parallel to the existing TWRbetween Hoi Kok Street and Tsuen Tsing Interchange; and

Widening of existing at-grade TWR between Tsuen Tsing Interchangeand Kwai Tsing Interchange from dual-3 lane to dual-5 lane.

1.6 Name and Telephone of Contact PersonMr. K. L. Cheung Senior Engineer/NTW 4

Civil Engineering Development Department

Tel. No. 2417 6370

2. OUTLINE OF PLANNING AND IMPLEMENTATION2.1 Responsibility of Parties

Civil Engineering Development Department is the Project Proponent who

has engaged a consultant to undertake the investigation study including the

Environmental Impact Assessment. Consultants will also be employed

later to undertake the detailed design and the supervision for the

construction phase of the Project.

2.2 Tentative Project TimetableThe Detailed Design and Tender is expected to commence in 2007 for


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3. POSSIBLE IMPACTS ON THE ENVIRONMENT3.1 Introduction

This section identifies the likely environmental impact of the proposed

works in both the construction and operational phase.

3.2 Construction Phase3.2.1 Gaseous Emissions

The main source of gaseous emissions will be emitted from diesel-powered

equipment used within the construction sites. However, since the number

of such plant required on-site will be limited, their gaseous emissions are

expected to be minor. Thus no impacts are expected from gaseous

emissions during the construction stage.

3.2.2 Dust

Construction activities such as handling and stockpiling of excavated

materials and truck movement on unpaved road will be the main dust

generating sources during the construction stage.

3.2.3 Odour

Odour impact is not anticipated during the construction phase.


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work is subject to statutory control under the Noise Control Ordinance.

3.2.6 Traffic Generation

Construction traffic are expected to increase the overall traffic volume in the

vicinity of the study area.

3.2.7 Liquid Effluents, Discharges or Contaminated Runoff

The potential water quality impacts include construction site runoff, liquid

spillage, sewage from the on-site construction work force and drainage from

construction sites.

3.2.8 Generation of Waste or by-products

Generation of wastes during the construction phase include surplus

excavated and inert material; general construction waste, demolition waste;

chemical waste; and general refuse.

3.2.9 Storage, Handling, Transport and Disposal of Dangerous Goods, Hazards

Materials or Wastes

Storage, handling, transport and disposal of dangerous goods, hazardous

materials or waste are not expected during the construction phase.

3.2.10 Risk of accidents which would result in pollution or hazard

The Yau Kom Tau water treatment works is a Potentially Hazardous

Installation (PHI).


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3.2.12 Disruption of Water Movement or Bottom Sediment

As only land based construction activities will take place, disruption of water

movement or bottom sediment are not expected during the construction

phase.

3.2.13 Unsightly Visual Appearance

During the construction of the project, the visual appearance is expected to

be poor. A detailed landscape and visual impact assessment should be

undertaken to identify the impacts and mitigation requirements to minimize

any potential impacts.

3.2.14 Ecological Impacts

The project would be within an extremely urban area and principally no

natural habitat would be affected. No important ecological resources have

been identified within the study area and ecological impacts are not

expected.

3.2.15 Impacts of Known Archaeological Sites

Within the study area, there are still some villages and clan grave. They

include Yau Kam Tau old village, Sam Tung Uk, Ho Pai, Wang Fat Ching

She as well as the ancient Tang clan grave between Pak Tin Pai and Chai

Wan Kok. They are all of very high cultural and historical heritage value.

3.3 Operational Phase


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3.3.2 Dust

Main source of dust during the operational phase will be from the vehicles

on the open road sections.

3.3.3 Noisy Operations

Road traffic noise from the open sections of the alignment would be the

main source of noisy operations during the operational phase. Due to the

proximity of some noise sensitive receivers to the proposed alignment, the

unmitigated alignment is expected to cause adverse noise impacts and the

use of direct mitigation measures is required. Assessment should be

carried out to assess the potential impacts from the proposed alignment andto identify the exact extent of mitigation measures required.

3.3.4 Risk of accidents which would result in pollution or hazard

The project is within 250m of the Kwai Chung Park area (former Gin

Drinkers Bay Landfill site) and in the proximity of the Yau Kom Tau Water

Treatment Works. A risk assessment would therefore be required for the

operation of the project.

3.3.5 Landscape and visual intrusion

The new and widened roads both at grade and on viaducts as well as

potential noise enclosures/barriers will have landscape and visual impact.

An assessment would therefore be required to minimize the impact.


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attached Drg. Nos. NTW Z1296A.

Table 4.1 Locations and Distances of Air and Noise Sensitive

Receivers from the Proposed Roadwork Project

Location ASR ID NSR ID Approximate

Distance from

Proposed RoadworkProject

Summit Terrace ASR1 NSR1 125

The Panorama ASR2 NSR2 70

Clague Garden Estate ASR3 NSR3 75

Skyline Plaza ASR4 NSR4 150

Waterside Plaza ASR5 NSR5 95

Rivera Garden ASR6 NSR6 300

CNEC Lee I Yao Memorial school ASR7 NSR7 100

Kwai Shing West Estate ASR8 NSR8 160

KCRC TW5 Development (City

side)*

ASR9 NSR9 60

KCRC TW5 Development (Bay

side)*

ASR10 NSR10 60

KCRC TW 6 Development* ASR11 NSR11 30

KCRC TW 7 Development* ASR12 NSR12 30

Kong Nam Industrial Building ASR13 55

Cable TV Tower ASR14 55Tsuen Wan Industrial Centre ASR15 30

Tsuen Wan Chinese Cemetery ASR16 320

Chun Shing Factory Estate ASR17 30

Kwai Shing Swimming Pool ASR18 200


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5. ENVIRONMENTAL PROTECTION MEASURES AND ANYFURTHER ENVIROMNETAL IMPLICATIONS

5.1 Noise5.1.1 Construction Phase

Construction noise could be controlled by the use of quiet constructionmethods and equipment. Construction activities should be limited to

daytime hours (0700-1900) Monday to Saturday only, otherwise a

Construction Noise Permit must be obtained from EPD. Good site practice

and noise management can be effective in reducing the impact of

construction site activities on nearby NSRs. Where applicable, the

following indicative control measures should be implemented to minimizeconstruction noise levels:

only well-maintained plant should be operated on-site and plant

should be serviced regularly during the construction programme;

machines and plant (such as trucks) that may be in intermittent use

should be shut down between work periods or should be throttled

down to a minimum;

plant known to emit noise strongly in one direction, should, where

possible, be orientated so that the noise is directed away from nearby

NSRs;

silencers or mufflers on construction equipment should be utilized

and should be properly maintained during the construction

programmes;

mobile plant should be sited as far away from NSRs as possible;

the use of quiet PME and reducing the number of PME operating


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5.1.2 Operational Phase

A package of direct mitigation measures would be recommended including:

low noise road surfacing for roads with speed limits greater than 50

kph; and

noise barriers/enclosures.

Further assessment is required to identify the impacts and mitigation

requirements to minimize any potential impacts.

5.2 Air Quality

5.2.1 Construction Phase

The likely air quality impact arising from the construction of the proposed

road alignment is related to dust nuisance, and gaseous emissions from the

construction plant and vehicles.

Dust suppression measures stipulated in the Air Pollution Control

(Construction Dust) Regulation should be followed by the contractor to

control any potential construction dust impact arising from the works sites

within relevant standards and guidelines, no further study is needed.

These typical control measures include:

where breaking of rock/concrete is required, watering should be

implemented to suppress dust generation, water spray should be used

during the handling of excavated material at the site and at active

cuts, excavation and fill sites where dust is likely to be created;


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work;

every vehicle should be washed to remove any dusty materials from

its body and wheels before leaving a construction site;

the load on the vehicles should be covered entirely by clean

impervious sheeting to ensure that the dusty materials do not leak

from the vehicle; and

the working area of any excavation should be sprayed with water

before, during and immediately after the operation so as to maintainthe entire surface wet.


No mitigation measure is proposed. However, it is recommended that

further assessment should be undertaken to identify the impacts andmitigation requirements where necessary.

5.3 Water Quality5.3.1 Construction Phase

It is considered that controls on discharge from land based construction

activities and proper site management procedures will minimize residual

water quality impacts to comply with limits stipulated in the Water Pollution

Control Ordinance criteria. As such, detailed water quality assessment is

not recommended.


Provided that appropriate mitigation measures are properly implemented,


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oily contents of the oil intercepts should be collected for reuse, or

transferred to an appropriate disposal facility;

pre-treatment of discharges resulting from routine tunnel washing

activities during operational stage should be undertaken to meet the

effluent discharge standards specified in the Technical Memorandum

of the Water Pollution Control Ordinance.

5.4

Waste


It is considered that with measures such as good construction practices and

proper waste management procedures, no adverse impact will be anticipated.

As such, detailed construction waste assessment is not recommended.

5.5 Landscape & Visual5.5.1 Construction Phase

The construction works will include temporary traffic management schemes,

cut and fill slope, use of heavy construction plant and site clearance. They

will exacerbate the landscape and visual effect on residential area and park

in the vicinity. It is considered that with measures such as good

construction practices are adopted to minimize the impact. Further

assessment will be required to recommend temporary mitigation measures

for the construction phase.



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Antique and Monument Office must be consulted and reported if there is any

suspected antique found in the course of construction.


It is anticipated that the operation of the project will have no effect on the

existing archaeological potential of the area. No detailed assessment will

be carried out.

5.7 Risk of Accidents at Landfill and Yau Kom Tau Treatment WorksThe landfill gas hazard assessment will be conducted in accordance with the

Landfill Gas Hazard Assessment Guidance Note (LGHA Guidance Note)

issued by EPD.

Chlorine is stored and used in the Yau Kom Tau Treatment Works. Risk

assessment will be conducted in accordance with the Individual Risk

Guideline endorsed by the Co-ordinating Committee on Land-use Planning

and Control relating to Potential Hazardous Installations.


For construction works adjacent to the Gin Drinkers Bay Landfill, safety

requirements will be stipulated to minimize the risk of fires, explosions,

asphyxiation of workers and toxicity effects.

The Yau Kom Tau Water Treatment Works is about 850 metres away from

the western end of the project. It is anticipated that, in view of distance,

construction works under the project will not impose risk on the water

treatment works.


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5.8 Summary of the Proposed Mitigation Measures

As discussed in the above section, mitigation measures have been proposed

to reduce the impacts associated with the proposed alignment. A summary

of the mitigation measures proposed for those environmental issues are

presented in Table 5.1.

Table 5.1 Summary of the Proposed Mitigation Measures

Environmental Issues Location Proposed Mitigation Measures

Construction Noise Within the works

boundary

Environmental pollution control

measures such as the use of quiet

PME, reducing the number of PME

operating concurrently and the useof movable noise barriers

Road Traffic Noise All open new

roads with speed

limits above 50

kph

Low noise road surfacing

Road Traffic Noise At locations near

noise sensitive

receivers

Noise barriers/enclosures

Construction Dust Within the works

boundary

Dust suppression measures

stipulated in the Air Pollution

Control (Construction Dust)

Regulation such as the use of water

splays, wheel wash facilities etc

Water Quality Within the works

boundary

Control on discharge from land

based construction with proper sitemanagement procedures

Construction Waste Within the works

boundary

Proper waste management

procedures

Landscape and Visual Within the works

b d

Landscaping works


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6. USE OF PREVIOUSLY APPROVED EIA REPORTS6.1 Title : West Rail Final Assessment Report West Kowloon to Tuen Mun

Centre Environmental Impact Assessment Vol. 1, Technical Annexes and

EM&A Manual

EIAO register reference number : EIA-149/BC

Time of Approval : March 1998

The assessments for the following environmental aspects addressed by theWest Rail EIA report for the area in the vicinity of Tsuen Wan and Kwai

Chung include:

noise especially for those noise mitigation measures provided;

air quality;

water quality;

landscape and visual;

archaeological and cultural;

ecology;

waste;

land contamination; and

hazards.

The noise assessments in the approved West Rail EIA report may be relevant

to the assessment for this roadwork project.

6.2 Title : Tsuen Wan Bay Further Reclamation, Area 35, Tsuen Wan

Engineering, Planning and Environmental Investigation

EIAO register reference number : EIA-002/1998

Time of Approval : Nov., 1998.


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