1                                  Introduction

1.1                            Background

In support of the Government of the Hong Kong Special Administrative Region (HKSARG)’s regional air quality improvement initiative, the Castle Peak Power Company Limited (CAPCO), a joint venture between CLP Power Hong Kong Limited (CLP Power) and Exxon Mobil Energy Limited (EMEL), proposes to install additional emissions control facilities on their Castle Peak Power Station “B” Units (CPB) to further reduce air emissions from the operations of these units.

CPB units use pulverised coal as the primary fuel.  All CPB units were commissioned during 1986 to 1990 with a unit size of 677 MW (gross).

It is CAPCO’s objective to responsibly manage the environmental impact of their operations and to meet HKSARG's environmental license requirements while providing reliable electricity supply.  Since its full commissioning, CPB has been retrofitted with low nitrogen oxide (NOx) burners for the boilers, flue gas conditioning systems, and upgrades of the electrostatic precipitators (ESPs) in addition to boiler optimisation improvements in recent years for improved particulates and NOx control.  As a result of these measures and together with the introduction of natural gas in the mid 1990s and increased utilisation of ultra low sulphur coal, emissions of NOx, sulphur dioxide (SO2) and particulates from all CAPCO facilities have already been reduced by 77%, 44% and 70% respectively over the 1990 to 2005 period when the total electricity demand has grown by about 80%.

Based on the CPB emissions control project description included in CAPCO and CLP Power’s 2005 Financial Plan which was accepted by HKSAR Government, the following additional emissions control facilities are currently proposed for implementation at CPB:

·       Selective Catalytic Reduction (SCR) for NOx reduction; and

·       Limestone Flue Gas Desulphurisation (LS FGD) for SO2 reduction.

While there are several other emission control technologies available for NOx reduction, final NOx control facility will be subject to design optimisation.  For the purpose of this Environmental Impact Assessment (EIA) Study, SCR has been selected as the most conservative process with respect to environmental impact.  This is due to the fact that the SCR system encompasses the facilities and elements associated with the other available NOx reduction technologies.

These facilities are expected to result in significant emission reductions of NOx and SO2.  Further reduction in particulate emissions is also anticipated as a result of the LS FGD process.

1.2                            Objective and Scope of the EIA

As defined under Section 9 (4) of the Environmental Impact Assessment Ordinance (EIAO)(Cap 499), the above-mentioned Emissions Control Project (the Project) is a material change to an exempted designated project (DP), the Castle Peak Power Station (CPPS) [Category D (Energy Supply), Item D.1 (Public Utility Electricity Power Plant) of Schedule 2, Part I], as a result of the changes introduced by the SCR and the LS FGD operations to the types and quantities of wastes, emissions and effluents.  The Project also includes elements which will qualify as DPs in their own right under Schedule 2 of the EIAO.

The main objective of this EIA Study is to provide a detailed assessment of the nature and extent of potential environmental benefits and impacts arising from the construction and operation of the Project in relation to the issues specified in the EIA Study Brief (No. ESB 134/2005), including air quality, noise, water quality, waste management, ecology, land contamination and landscape and visual impacts.

1.3                            Approach to the Study

The assessments in this EIA Study are conducted using well-proven and internationally accepted methods based on the worst-case conditions associated with the construction and operation of the Project.