1                                            Introduction

1.1                                      Background to the Study

HongKong Electric Company Ltd (HEC) is planning to retrofit the two existing 350MW coal-fired generating Units L4 and L5 of Lamma Power Station with Flue Gas Desulphurization (FGD) Plant for reducing sulphur dioxide emission in support of Government policy objective to improve the air quality of the Pearl River Delta.

Having considered the site constraints and current development of the emission control technologies, HEC proposes to adopt the “Wet Limestone-Gypsum” process for Units L4 & L5 FGD plant retrofit project.  This technology has been proved reliable and effective based on operating records of FGD plants of the same technology installed for exiting coal-fired Units L6, L7 & L8.

To provide space for installing the proposed FGD plants, two existing No. 4 and No. 5 Light Oil Tanks each of 250m3 capacity located in front of Units L4 & L5 boiler will be demolished.  This is a designated project under the Schedule 2 – Part II of the EIA Ordinance.  A project profile (PP) was prepared and submitted to the EPD on 21 September 2005 to apply for a Study Brief to conduct an Environmental Impact Assessment (EIA) for Lamma Power Station Units L4 & L5 FGD Plant Retrofit Project.  The PP highlights the potential land contamination issues arising from the demolishing of the two oil tanks and requires land contamination assessment to be carried out to address the potential land contamination issues.

Environmental Resources Management (ERM) was commissioned by HEC in September 2005 to conduct a land contamination assessment of the Site, in accordance with the PP requirements.

Site inspection including sampling and analysis will be conducted to identify potential sources of soil and groundwater contamination from previous operation.  Dismantling of the two oil storage tanks and associated facilities would potentially cause spillage of the fuel, if not properly managed.  Special care will be exercised during the dismantling works in order to identify and record any contamination detected for possible assessment and sampling related to any future developments on the Site.  The demolition of the oil tanks is scheduled to commence in March 2006 to coordinate with civil construction for the proposed FGD plants.

This report describes the Contamination Assessment Plan (CAP) for the land contamination assessment.

1.2                                      Objective of the CAP

The purpose of the CAP is to provide information, guidance and instruction for characterising land contamination at the proposed project area prior to the site formation works.  This CAP aims to provide systematic procedures for identifying any land contamination, carrying out the site investigation and evaluating the results to identify the nature and extent of the contamination.  The specific tasks of the CAP include:

·       Review of the land history of the Site in relation to possible land contamination;

·       Identification of potential contamination and associated impacts, risks or hazards; and

·       Preparation of a plan for the actual contamination assessment, which includes a proposal on soil and where appropriate, groundwater sampling and analysis, for agreement with the EPD prior to its implementation.

The findings of the site investigation will be evaluated and reported in the Contamination Assessment Report (CAR).  If the findings confirm that the Site is contaminated, a Remediation Action Plan (RAP) will be prepared and submitted to EPD for approval.

1.3                                      Environmental Legislation and Non-statutory Guidelines

The assessment of land contamination sources and the potential impacts to particular development projects will be investigated in accordance with the guidelines set out in the Environmental Protection Department’s (EPD) Practice Note for Professional Person (ProPECC) PN3/94Contaminated Land Assessment and Remediation”; and EPD’s Guidance Notes for Investigation and Remediation of Contaminated Sites of Petrol Filling Stations, Boatyards, and Car Repair/Dismantling Workshop (Guidance Notes).

The Dutch Indicative Index (Dutch ABC List) as given in the ProPECC PN 3/94 has been adopted by the EPD as the criteria for interpretation of the assessment results and determination the level of soil contamination.

Under the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM), Annex 19: Guidelines for Assessment of Other Impacts, consideration should be given during development and redevelopment projects to a number of potentially contaminating historical land uses, which have the potential to cause, or have caused, land contamination.  This includes developing a CAP for the investigation where such land uses are identified, preparation of CAR after such investigation has been completed, and if contamination is confirmed, a RAP should be prepared.