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.
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.
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)
PN3/94 “Contaminated 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.