ASB Biodiesel (
The Project is classified as a Designated Project
under the Schedule 2 Part I of the Environmental Impact Assessment Ordinance (EIAO) and therefore the construction and
operation of the Project will require an Environmental Permit.
An Environmental Impact Assessment (EIA)
Study has been conducted to evaluate the potential environmental impacts due to
the Project in accordance with the EIA
Study Brief (ESB-178/2007) issued under the EIAO and the guideline on assessment methodology provided in the Technical Memorandum on Environmental Impact
Assessment Process (EIAO-TM). The
overall objectives of the EIA Study are to provide information on the nature
and extent of potential environmental impacts arising from the Project; to
recommend appropriate mitigation measures to control the potential environmental
impacts so that it complies with the requirements of the EIAO-TM, and to
confirm the environmental acceptability of the Project. Key environmental issues identified in the EIA Study Brief include air quality, noise, water quality, marine
ecology and hazard to life.
The general approach for the assessment
includes a description of the baseline environmental conditions, identification
and evaluation of potential impacts and recommendations for mitigation measures
and an environmental monitoring programme.
The assessments in this EIA Study are conducted using well-proven and
internationally accepted methods based on reasonable worst-case conditions.
The
proposed 100,000 tpa biodiesel
plant will use multi-feedstock (primarily from WCO and trap grease, and
supplemented with PFAD and animal fats) to produce biodiesel which complies
with international standards. The
biodiesel will be sold to local and international markets.
The proposed biodiesel plant will include a GTW pre-treatment facility
(with a designed treatment capacity of 200,000 tpa or
about 606 tpd) which will recover oil and grease from
GTW and a wastewater treatment plant (with a designed treatment capacity of 170,000
m3 per annum) for the treatment of wastewaters generated from the
GTW pre-treatment facility and the biodiesel production processes. The biodiesel plant will consist of a number
of storage and process tanks. Figure 2.1 shows the proposed
layout of the biodiesel plant. The
entire biodiesel production process is program-controlled to maintain a high
level of safety and uniform quality of the final product.
The
Project Proponent will adopt the BDI technology, a well-proven biodiesel
production technology for the design of the biodiesel plant in order to achieve
a high efficiency (which is able to utilise oil and grease with a high level of
free fatty acids (over 20%) and completely transform them into biodiesel and
three useable by-products, namely glycerine, fertilizer, and bioheating oil) and safety standard in the biodiesel
production operation. No waste will be
generated from the biodiesel production process. The biodiesel produced will meet the
specification of the European standard CEN EN 14214.
As the Project Site has been formed, no major
earthworks will be required for site formation.
The reinforced concrete buildings will be constructed on site using
ready-mix concrete and conventional construction methods. The pre-fabricated structural steelworks and
storage tanks will be assembled on site using hydraulic and tower cranes.
No dredging of marine sediments or reclamation works
will be required for the construction of the jetty. The jetty will be constructed in the form of
a piled deck. Marine bored piles will be
driven through the existing rubble mound seawall to competent bearing strata by
a piling rig mounted barge. Concrete
infill of the piles will be undertaken prior to the placement of the trellis
beam and pre-cast concrete panels.
The development programme for the biodiesel plant is
outlined in Table 2.4a.
Table 2.4a Tentative
Project Development Programme
|
Activities |
Timeline |
|
Engineering design and equipment procurement |
April 2008 to
March 2009 |
|
Commencement of
the construction of the Biodiesel plant and installation of equipments |
March 2009 to February 2010 |
|
Statutory Inspection |
February 2010 to April 2010 |
|
Commencement of testing and checkout |
April to June 2010 |
|
Commencement of the Biodiesel plant |
June 2010 |
The environmental
outcomes associated with the construction and operation of
the proposed biodiesel plant have been assessed in the EIA Study. The key findings and recommendations are
summarized below.
The Project Site has been formed and is currently
vacant. No major earthworks will be
required for the site formation works and only minor excavation works will be
required for the construction of the foundation works and site utilities. The storage tanks and process equipment will
be pre-fabricated off-site and assembled on site using hydraulic and tower cranes and hence minimal
dust will be generated from this activity.
Dust generated from the minor excavation works and concreting works for
the construction of site buildings will be minimal. The dust and air emissions generated from the marine works will be
minimal.
With the implementation of dust suppression measures
stipulated under the Air Pollution
Control (Construction Dust) Regulation and the adoption of good site
practices, no adverse construction dust impact is anticipated. Dust monitoring during the construction phase
is therefore considered not necessary.
The boiler and biogas stacks (if in operation) and the
exhaust of the
The potential odour impact due to the discharge of exhaust air from the
final air scrubber of the on-site wastewater treatment plant has been
evaluated. After scrubbing, the odour concentration will be significantly reduced and will
not cause adverse odour impacts to the identified
ASRs.
It is concluded that the
construction and operation of the biodiesel plant will not cause adverse air
quality impacts and will comply with the EIAO-TM
requirements.
Powered
Mechanical Equipment (PME), such as air compressors, hydraulic hammers,
excavators etc, will be used for the construction of the biodiesel plant and the
associated jetty. The predicted
construction noise levels at the identified representative Noise Sensitive
Receivers (NSRs) range from 48 dB(A) to 64 dB(A) and
48 to 55dB(A) for residential premises and an educational institution,
respectively. These levels are well
below the noise criteria for domestic premises and educational institutions. Therefore,
the NSRs will not be adversely affected by the
construction of the Project. Good
construction site practices will be implemented by the Contractor to further
minimise the noise impact.
The
operation of fixed plant (such as pumps, water cooling tower, air-cooled chiller, blowers, and reactors) will generate noise. The noise levels at the identified NSRs due to operation of the fixed plant have been
predicted based on a set of conservative assumptions. Due to the large separation distances
between the NSRs and the noise sources, the predicted
operational noise levels range from 40 to 49 dB(A) and 38 to 47 dB(A) during
the corresponding day-time and night-time periods. These noise levels comply with the day-time
and night-time noise criteria of 60 and 50 dB(A),
respectively. As no adverse noise impact
during the operational phase is anticipated according to EIAO-TM, noise monitoring is considered not necessary.
The
construction works for the Project will mainly be land-based. With respect to the nature and relatively
small scale of the land based construction activities, the potential water
quality impacts are considered minimal with the implementation of the good site
practices outlined in ProPECC PN 1/94 “Construction Site Drainage”.
A
jetty (50 m long and 26 m wide) in a form
of a reinforced concrete deck supported by bored piles will be
constructed. A total of about 60 piles
(approximate diameter of 1 m each) will be constructed and will be driven
through the existing rubble mound seawall.
No dredging or
reclamation works will be required. The water quality impacts due to the piling
activities will be minimal and no adverse water quality impact is
anticipated.
As
no adverse water quality impact is anticipated, no water quality monitoring is
considered necessary during the construction phase.
The
cross-sectional area of each pile underwater has been estimated to be 0.8m2. It is estimated that the volume of each pile
underwater will range from 8m3 to 9.6 m3. Although there may be localised
effects due to the physical resistance of the piles, the water flow through the
piled structure will generally be maintained.
It is not expected that the piles will cause adverse impacts to water
flow regime at the jetty during the operational phase.
A
surface water drainage system will be provided to collect stormwater
runoff from the Project Site. Oil
interceptor will be installed at strategic location of the Site to prevent any
oily water discharges into the stormwater drain.
Wastewater
from the biodiesel production process will be collected and treated prior to
discharge to the foul sewer leading to the Tseung Kwan O Sewage
Treatment Works.
The tank farm area will be bunded
to contain any spillage or leakage of materials from the storage tanks. Contaminated water collected from the bunded area will be diverted to the on-site wastewater
treatment plant for treatment.
All
materials to be used and stored on site (except for the gas oil) are
biodegradable and hence the potential for of land contamination or
environmental pollution due to the spillage of materials during handling and
transfer, and leakage of tanks will be less severe. Nevertheless, the plant / equipment and tank
farm are designed to comply with relevant local regulations and international
standards. Measures have been put in
place to prevent spillage of materials during handling and transfer. For example, dry coupling will be
used to connect two loading/unloading pipes or a flexible hose to a transfer
pipe in order to avoid any leakage of the materials at the joint. The
loading/unloading area will be bunded to contain any
potential spillage of materials. In
addition, the operations will be undertaken at the paved loading/unloading
station and will be manned by trained staff and closely monitored with flow
control equipment.
Any spillages will be
contained and the spill be absorbed by appropriate absorbents. The area will be properly washed and the
wastewater will be conveyed to the on-site wastewater treatment plant for
treatment. For accidental spills during
the transportation of biodiesel off the site, retainer booms will be deployed
around the barge and the contaminated areas to prevent the spillage
spreading. A detailed emergency response plan will be developed
to define the detailed actions to be taken in the event of a spill during the
detailed design stage.
Based
on the above and with the provision of appropriate mitigation measures, no
adverse water quality impacts are anticipated.
Stormwater and treated effluent discharged
from the site will be monitored on monthly intervals during the operational
phase.
No dredging and reclamation works
will be required. Permanent loss of a
small stretch ([2]) of
low ecological value marine habitats at the artificial seawall is expected due
to the marine works for jetty construction.
Pile surfaces can, however, serve as artificial habitat for the
settlement and re-colonisation of marine assemblages. Residual impacts are expected to be low.
As no adverse water quality impact
is expected due to construction activities, there will be no secondary impacts
to ecology. It is considered that environmental monitoring is not
required. Nevertheless, a monthly site
inspection is recommended to ensure that the recommended mitigation measures on
water quality are properly implemented such that secondary adverse impacts on
marine ecological resources can be avoided and minimised.
As no adverse water quality and hydrodynamic
impacts are expected due to operation of the biodiesel plant, the potential impacts to marine ecological
resources are expected to be minimal.
No adverse impacts to marine ecology are expected.
No
monitoring and audit will be required during the operational phase.
A
Quantitative Risk Assessment (QRA) has been conducted for the Operational Phase
of the Project. The potential risks to
the off-site population have been estimated based on the population levels
(including the planned population at the vacant land adjacent to the biodiesel
plant). The assessment shows that
principal hazards arise from handling of methanol, which is highly flammable,
in the process area, storage of methanol and other combustible fluids like biodiesel
and the unloading operations for the barges and road tankers.
The
overall risk levels estimated for the operational phase of the Project are
within the “acceptable” region of Hong Kong Risk Guidelines. Therefore the Hazard to Life criteria
stipulated in Annex 4 of EIAO-TM are met.
With
respect to the findings and recommendations of the EIA Study, no noise, water
quality and marine ecological monitoring during the construction phase will be necessary. However, monthly site inspections will be
carried out to audit the compliance of the Contractor with regard to noise
control and water quality.
With
respect to the findings and recommendations of the EIA Study, no noise and marine
ecological monitoring during the operation phase will be necessary.
Monitoring of key pollutants (NOx, CO, SO2 and NMOC) in the flue
gases of the boilers and biogas flare (if in operation), and methanol and acetyldehyde in the exhaust gas of the Process Building
will be carried out at monthly intervals for the first 12 months of
operation. If the monitoring results of
the first year monitoring meet the limit level, the monitoring will be reduced
to half-yearly intervals for the whole operational stage. Exhaust gas temperature and exhaust gas
velocity will also be monitored at the same frequency.
The
odour emission of the final air scrubber will be monitored at monthly intervals
for the first two operational years of the biodiesel plant.
Odour
patrol will be carried out along the Project Site boundary on monthly basis during the first year of
the operation of the biodiesel plant to
confirm that the operation of the biodiesel plant will not cause odour nuisance. If there is no exceedance
of action limit or there is no substantiated odour compliant during the first
year of operation, the monitoring frequency will be reduced to quarterly
intervals in the second year of the operation. During the
second year of operation, if the action level is triggered, the frequency will
be resumed to monthly until compliance with the action level for three
consecutive months is obtained and the frequency will be reduced to quarterly
interval thereafter. If the action level
is not triggered for four consecutive quarterly monitoring, the monitoring can
be terminated.
To
ensure that the stormwater or effluent discharged
from the Project Site will comply with the discharge standards, the
quality of the stormwater/effluent will be monitored at the
terminal manholes of the stormwater and foul water
drainage systems on a monthly basis.
An Implementation Schedule, containing the
recommended mitigation measures, monitoring and audit requirements, and the
implementation agent are presented in Annex
D of the EIA
Report.
In
accordance with the EIA Study Brief and
the guidance in the EIAO-TM, the EIA
Study has identified and assessed potential environmental impacts associated
with the construction and operation of the Project.
The
study concludes that with the implementation of the recommended environmental
control measures during the construction and operational phases, no
unacceptable environmental impacts are envisaged.
EM&A
activities are recommended to ensure the effectiveness of the recommended
mitigation measures.
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Contents
1.1 Background 1
1.2 Objectives 1
2 Project Description 3
2.1 Plant Layout and Processes 3
2.2 Technology to be Used 3
2.3 Construction of the Biodiesel Plant 3
2.4 Project Planning and Implementation 4
3 Environmental IMpacts 5
3.1 Introduction 5
3.2 Air Quality 5
3.3 Noise 6
3.4 Water Quality 6
3.5 Ecology 8
3.6 Risk
Assessment 8
3.7 Environmental Monitoring and Audit 9
4 Overall Conclusion 11