1                    Introduction

 

1.1              Introduction

 

The Study for which this Environmental Impact Assessment and Final Site Selection (EIAFSS) Report has been developed is the Detailed Site Selection Study for a Proposed Contaminated Mud Disposal Facility within the Airport East/East of Sha Chau Area (Agreement CE 12/2002 (EP)) - hereinafter referred to as the Study.

 

This EIAFSS Report addresses the potential environmental impacts associated with the construction and operation of the Proposed Contaminated Mud Disposal Facility within the Airport East/East of Sha Chau Area.

 

The Project is classified as a Designated Project by virtue of Item C (Reclamation, Hydraulic and Marine Facilities, Dredging and Dumping), Item C.10 (A Marine Dumping Area) and C.12 (A Dredging Operation Exceeding 500,000 m3) of Part I of Schedule 2 under the Environmental Impact Assessment Ordinance (Cap. 499) (EIAO).

 

This report is prepared by ERM-Hong Kong, Limited (ERM) in accordance with the EIA Study Brief (No. ESB-095/2001) and the Technical Memorandum of the Environmental Impact Assessment Process (EIAO-TM).  The Study Area for the Project is presented in Figure 1.1a.

 

1.2              Background to the Study

 

From December 1992 to November 1997, a series of purpose-dredged seabed pits at East Sha Chau (Contaminated Mud Pits (CMPs) I to III) were used to dispose of dredged contaminated mud in Hong Kong.  In 1996, as the capacity in these pits began to dwindle, the Hong Kong Special Administrative Region (SAR) Government commissioned a study to examine the need for continued marine disposal of dredged material in Hong Kong in order to manage ongoing contaminated sediment arisings ([1]).  The study reviewed potential land-based options in Hong Kong, including strategic landfills, treatment of materials, and the incorporation of contaminated dredged material into land reclamation projects, but found each to have inherent drawbacks.  In contrast, the study's review of environmental monitoring data collected at CMPs I-III from 1992-1995 concluded that there was no evidence of contaminant impacts on biota due to disposal, and that contaminants in dredged materials had been successfully contained.  The study therefore recommended continued disposal in capped seabed pits in the East of Sha Chau area as the preferred option.

 

This finding led the Hong Kong SAR Government to commission an Environmental Impact Assessment (EIA) evaluating the use of disused borrow pits in the East of Sha Chau area as the next contaminated mud disposal facility.  This facility, known as CMP IV, consisted of three pits (CMP IV a, b and c) which had been dredged for sand during construction of the new airport at Chek Lap Kok and represented a total capacity of approximately 30 million cubic metres.  The CMP IV EIA study ([2]) formulated an environmental design for disposal operations, which included specifications for disposal rates, cap thickness, and backfilling level.  The Study concluded that impacts to water quality, marine ecology, air and noise were expected to be maintained within acceptable limits under the specifications of the agreed Operations Plan.  The CMP IV EIA Report was endorsed by the Advisory Council on the Environment (ACE) in March 1997.

 

1.3              Purpose of the Study

 

Capacity to dispose of contaminated mud is presently predicted to be exhausted by early 2009 with the completion of backfilling of CMP IV at East of Sha Chau.  These recently revised predictions have indicated that there has been a reduction in the forecasted amounts of contaminated mud requiring disposal, primarily as a result of a decrease in marine dredging operations in Hong Kong.

 

Several factors may still act to affect the arisings of contaminated mud including:

 

·                reprioritization and reprogramming of projects;

·                increasing control of land-based contaminant sources; and,

·                continued implementation of ETWBTCW No. 34/2002. 

 

When CMP IV is full, a new environmentally acceptable disposal capacity for essential arisings will be required.  The assignment Strategic Assessment and Site Selection Study for Contaminated Mud Disposal (Agreement CE 105/98) recommended a Contained Aquatic Disposal facility (CAD - capped seabed pit such as those already used at East of Sha Chau) at Airport East ([3]).  Although members of ACE had no objection to proceeding with the recommended EIA, they considered that all sites, in particular the remaining portions of East of Sha Chau, and other disposal options, in particular a confined disposal facility (CDF – material confined within an artificial island) should still be considered.  To meet these requirements of ACE, the present study first identifies the most suitable sites and disposal option within both the Airport East and East of Sha Chau areas (Figure 1.1a) and, secondly it evaluates the environmental acceptability of impacts associated with construction and operation of these, through an Environmental Impact Assessment (EIA), and thirdly, based on a comparison of the outcomes of the two EIAs, a preferred disposal facility is recommended.  The site and disposal options are considered in Part 1, Section 2 of this EIAFSS, the two EIAs in Parts 2 and 3, and the recommended disposal facility in Part 4.

 

1.4              Purpose of this EIAFSS Report

 

The purpose of the EIAFSS 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, to 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;

·                The acceptability of residual impacts after the proposed mitigation measures are implemented; and,

·                A recommendation of the preferred facility for implementation.

 

The detailed requirements of the EIA Study are set out in the EIA Study Brief.  The objectives of the EIA Study are:

 

(i)             to describe the Project and associated works together with the requirements 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 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 impact to water quality and to propose measures to mitigate these impacts;

(v)           to identify and quantify any potential impact to marine ecology and to propose measures to mitigate these impacts;

(vi)         to identify any negative impacts on fisheries and to propose measures to mitigate the impacts;

(vii)       to identify the human health risk and ecological risk associated with consumption of seafood from the project area;

(viii)      to identify and quantify any potential impacts to Chinese White (Indo-Pacific Humpback) Dolphins and to propose measures to mitigate the impacts;

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

(x)          to identify and quantify the potential long-term impact of seabed ecology and bio-accumulation of contaminants in biota of the subject site and to propose measures to mitigate the impacts;

(xi)         to identify any potential noise impacts to the sensitive receivers during construction and operation and to propose measures to mitigate these impacts;

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

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

(xiv)     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;

(xv)       to recommend the environmentally preferred location for the facility within the study boundary;

(xvi)     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 the identified environmental impacts and cumulative effects and reduce them to acceptable levels;

(xvii)    to design and specify environmental monitoring and audit requirements to ensure the effective implementation of the recommended environmental protection and pollution control measures;

 

As specified by the EIA Study Brief, the EIA has addressed the following key environmental issues associated with the construction and operation of the Project.

 

·                water quality impact associated with dredging works and construction and operation of the disposal facilities;

·                cumulative water quality impact, including the discharges from the Siu Ho Wan Sewage Treatment Works outfall;

·                human health risk and ecological risk associated with consumption of seafood from the project area;

·                impact on marine ecology of the Sha Chau and Lung Kwu Chau Marine Park during construction and operation of disposal facilities;

·                potential long term impact of seabed ecology and bio-accumulation of contaminants in biota of the subject site;

·                impact on the Chinese White (Indo-Pacific Humpback) dolphins and artificial reef complexes during the construction and operation of the disposal facilities;

·                impact on capture fisheries during construction and operation stages of the disposal facilities.

 

1.5              Structure of this Report

 

This EIAFSS Report comprises the following parts and sections.

 

PART 1

MAIN INTRODUCTION

Section 1

Presents the introduction to this EIAFFS Report and the background to this Study.

Section 2

Provides information on the consideration of alternatives for the siting, design and operation of the Project.

Section 3

Details the legislation and standards that are applicable to the assessment of impacts of the construction and operation of the Project.

Section 4

Provides information on the baseline environmental conditions concerning water quality, marine ecology, fisheries, noise and cultural heritage of the Study Area.

PART 2

EIA OF SOUTH BROTHERS

Section 1

Provides a description of the Proposed Facility at South Brothers highlighting the key construction and operation activities.

Section 2

Presents the findings of the water quality impact assessment.

Section 3

Presents the findings of the marine ecology impact assessment.

Section 4

Presents the findings of the fisheries impact assessment.

Section 5

Presents the findings of the hazard to health impact assessment.

Section 6

Presents the findings of the noise impact assessment.

Section 7

Presents the findings of the cultural heritage assessment.

Section 8

Provides a summary of the conclusions and environmental outcomes.

 

 

PART 3

EIA OF EAST OF SHA CHAU

Section 1

Provides a description of the Proposed Facility at East of Sha Chau highlighting the key construction and operation activities.

Section 2

Presents the findings of the water quality impact assessment.

Section 3

Presents the findings of the marine ecology impact assessment.

Section 4

Presents the findings of the fisheries impact assessment.

Section 5

Presents the findings of the hazard to health impact assessment.

Section 6

Presents the findings of the noise impact assessment.

Section 7

Presents the findings of the cultural heritage assessment.

Section 8

Provides a summary of the conclusions and environmental outcomes.

PART 4

RECOMMENDED SITE & DISPOSAL OPTION

Section 1

Presents a comparison of the environmental outcomes of the EIAs on each facility.

Section 2

Presents the recommended site and disposal option.

Section 3

Presents the schedules and programmes for environmental monitoring and audit.

Section 4

Presents the prescription for the detailed design, construction and operation of the facility.

Section 5

Provides a summary of the conclusions and environmental outcomes drawn from the detailed assessment of the Project.

 


([1])           EVS Environment Consultants (1996a)  Review of Contaminated Mud Disposal Strategy and Status Report on Contaminated Mud Disposal. Final Report.  For the Civil Engineering Department, Hong Kong Government.

 ([2])         ERM – Hong Kong, Ltd (1997)  EIA for Disposal of Contaminated Mud in the East Sha Chau Marine Borrow Pit.  EIA Report.  For the Civil Engineering Department, Hong Kong SAR Government..

 ([3])          ERM - Hong Kong, Ltd (1999)  Strategic Assessment and Site Selection Study for Contaminated Mud Disposal.  Final Report.  For the Civil Engineering Department, Hong Kong SAR Government.