The Liantang/Heung
Yuen Wai Boundary Control Point (BCP) project
(hereafter ‘HKLTH’) tunnel construction works, which will connect the new BCP
with Fanling Highway, require the use of explosives at
three worksites, namely at Sha Tau Kok Road – Wo Hang
Section (North Portal), Po Kat Tsai Road (Mid Ventilation Portal), and Tong
Hang Tung Chuen (South Portal). To enable a timely delivery of
explosives to worksites and in order to meet the proposed construction work
programme, an Explosives Storage Magazine (Magazine) is required and the
purpose of the magazine is to maintain progress rate for construction
activities.
The existing Tai Lam
Explosives Magazine (Tai Shu Ha, Yuen Long District, New Territories, Land
Allocation GLA-TYL 1288, forthwith known as ‘TLEM’) has been licensed and is
currently in use by the MTRC for the construction of the XRL until end 2015
(Environmental Permit No. EP-349/2009/L). It is being used by the MTR XRL 824
Contractor. The TLEM will be
available once XRL work is complete and Dragages Hong
Kong Limited (DHK) , contracted by Civil Engineering and Development Department
(CEDD) for the HKLTH tunnel construction works, intends to continue using it
from late 2015 or early 2016 (expected January 2016) to December 2017.
The Project concerns the storage and transport of
explosives. It encompasses:
·
the use of the existing TLEM
from late 2015
or early 2016 (expected January 2016) to December 2017
with the same operation as current users;
·
Explosives transport from
the existing TLEM to three worksites by DHK, using trucks approved by Civil Engineering and
Development Department (CEDD)’s Mines Division
(Mines); and
·
Decommissioning
of the existing TLEM after operation.
The approved Hong Kong
Section of Guangzhou-Shenzhen-Hong Kong
Express Rail Link (XRL) EIA Report (No. AEIAR-143/2009) (hereafter ‘XRL
EIA’) has been reviewed specifically for the environmental impacts arising from
operation of the TLEM. The scope of
the XRL EIA was far broader than just the TLEM and it is considered that in
addition to a Hazard to Life Assessment, the various environmental media
included in the XRL EIA that are relevant to the TLEM Project are Ecology,
Airborne Noise, Air Quality and Waste Management with other media covered in
the XRL EIA considered either of minor importance or not relevant to the
current Project.
There are no known
existing, committed and/or planned projects in the vicinity of the Project that
could potentially cause cumulative environmental impacts through their
interaction with the Project.
For
the XRL EIA, a long list of potential locations for explosives magazine sites
were identified, reviewed and short-listed for further detailed study and
discussion with Mines. Factors
considered included:
·
External
separation distance - the distance from the explosive stores to inhabited areas
and sensitive receivers – following the required
minimum internal and external separation distances from the magazines as per
standards specified by the Hong Kong Commissioner of Mines (CoM).
-
In addition, it is preferable to limit the
transportation distances as far as practicable when considering the possible
location of a magazine. This is
particularly pertinent given explosives are not permitted within road tunnels,
and there would be a considerable distance of about 40 km to 50 km
for explosives transported from northern New Territories to Kowloon via above
ground or at grade roads, and vice versa;
·
Access
for Mines Division explosive delivery vehicles;
·
Site
constraints such as existing conditions;
·
Land
availability; and
·
Potential
environmental and heritage impacts.
The
magazine site selection process for the XRL project is documented in Working Paper No. 13A –Explosives Magazine
Site Selection and two explosives magazine sites were selected as being
necessary to store the explosives for the XRL project, one being the TLEM site
(and the other at So Kwun Wat).
The
selection of the TLEM site for the current Project has the benefits of being:
already constructed so there are no construction impacts or land conversion
issues; used for exactly the required purpose now which would imply any
operational as well as decommissioning impacts associated with the current
Project will be acceptable; available from end 2015 which suits the HKLTH project tunnelling
schedule; and in a suitable location for the HKLTH project. In addition,
since there is no requirement to build a new magazine site, the timeline for
the tunnel Project may be expedited as well as there being no requirement to
build a new magazine site which may cause more significant environmental
impacts elsewhere.
The location of the TLEM is illustrated in Figure 1.1 and its key components are:
(i) Two stores each with a capacity of
400 kg explosives;
(ii) Secure
fence;
(iii) CCTV
system;
(iv) Guard house; and
(v) Street
fire hydrant water tank (245 m3) and 2 pumps.
In
addition, the Project will require the delivery of explosives from the TLEM
using trucks approved by Mines, to three HKLTH worksites located at:
·
Sha
Tau Kok Road – Wo Hang Section (North Portal);
·
Po
Kat Tsai Road (Mid Ventilation Portal); and
·
Tong
Hang Tung Chuen (South Portal).
For this
Project, explosives transport will be scheduled with less than 200 kg of
explosives per truck and a total of two to eight (2 – 8) deliveries per day
will be carried out to the worksites and maximum seven (7) days per week. Only the amount of explosives required
for blasting work will be delivered to TLEM by Mines. Before the commencement of
decommissioning works, no surplus explosives will be stored at the explosives
magazine.
The
decommissioning works are expected to last for about one month and include dismantling and removing associated
features of the two explosive stores (e.g. CCTV, lighting etc);
demolishing the earth bunds and two explosive stores; removing concrete debris,
all fire service facilities and all ground services including guard house, road
furniture and lighting; removing the fire hydrant water tank; removing the
container guard house and any temporary steel works; and demolishing the paved
road for reinstatement of planting.
The
EIA Study was conducted in accordance with the EIAO Study Brief ESB-280/2014,
following the guidelines on assessment methodologies in the Technical
Memorandum on Environmental Impact Assessment (EIAO-TM). It provides information on
the nature and extent of any environmental impacts arising from the operation
and decommissioning of the Project (there is no construction phase), noting
that the operation of the magazine site will remain largely the
same as for the current XRL project.
The EIA Report largely
follows the approved XRL EIA which assessed the impacts from the construction
and operation of the TLEM, reviewing the relevant information and updating it
as necessary. It also includes a
hazard to life assessment. No key
activities are known to take place concurrently and therefore it is assumed
there will be no cumulative impacts from the Project.
The approved XRL EIA had a
far broader scope than just assessing the environmental impacts of the TLEM and
after review of the full XRL EIA the environmental media relevant to the TLEM
are Ecology, Airborne Noise, Air Quality and Waste Management with other media
of minor importance, including Water Quality and Landscape and Visual.
Ecology
Reinstatement planting at
the TLEM site will be carried out upon completion of the Project in 2017 and the
decommissioning of the TLEM. Assuming that this reinstatement
planting is carried out by DHK as recommended in the approved XRL EIA report
(according to the Vegetation
Survey Report and the Tree
Planting and Landscape Plan TLP-10: Works in Yuen Long District (Tai Shu Ha), which
both fall under the requirements of the XRL EIA study), no adverse impacts on ecology are
expected from this Project.
Noise
The
closest Noise Sensitive Receiver is over 290 m from the Project Site
boundary and no adverse noise impact from the operation of the Project is
anticipated. Equally no adverse
noise impacts are anticipated during decommissioning which will last for
approximately four (4) weeks and assuming general noise control measures, as
listed in Recommended Clauses for
Construction Contracts – Section 3 - Noise Control, are adopted. Noise monitoring at the NSR is therefore
not required at either operation or decommissioning and therefore no
environmental monitoring and audit is required for noise as part of the overall
EM&A programme.
Air
Quality
Operation
of the magazine site will remain the same as that for the current XRL
project. The operational activities
involve the delivery of explosives to and from the Project Site on a daily
basis. Potential sources of air
quality impact include dust emissions from the operation of explosives delivery
vehicles from the magazine to the work areas, with about two to eight trips per
day. Roads to/from and within the
Project Site will be paved, thus dust impact from the operation of the magazine
site is anticipated to be insignificant.
Decommissioning of the magazine site has the potential to cause dust
emissions. Since the decommissioning
works will be small scale, the potential air quality impact is expected to be minimal
with the implementation of proper dust control measures such as those
stipulated under the Air Pollution
Control (Construction Dust) Regulation and the adoption of good site
practice. Air quality monitoring
and audit is not considered necessary during the operation of the Project as no
adverse air quality impact is anticipated.
Waste Management
The amount of general
refuse generated from the operation and decommissioning of the magazine site is
expected to be small. General
refuse will be stored and disposed of separately from chemical waste.
Construction and Demolition (C&D) materials from the decommissioning will
also be handled and disposed of appropriately. Provided that general refuse is removed
from the Project Site regularly during operation and decommissioning (e.g. once
per day) and C&D materials is disposed of appropriately, no adverse
environmental impact related to handling and disposal of wastes is expected.
Other
Environmental Considerations
No
adverse water quality or landscape and visual impacts from operation of the
Project are anticipated. Therefore,
mitigation measures and environmental monitoring and audit during the
operational phase are not considered necessary.
During decommissioning, no adverse
landscape and visual impact is expected.
No adverse water quality impact is expected during decommissioning
either, considering the small scale and short duration of works activities and the implementation
of proper site runoff and soil erosion control measures in accordance with the guidelines
stipulated in EPD’s Practice Note for
Professional Persons on Construction Site Drainage (ProPECC
PN1/94).
This
Project is also considered to have no impacts on certain environmental media
covered in the XRL EIA, namely Cultural
Heritage, Fisheries, Ground-borne Noise, Land Contamination, Landfill Gas
Hazard and the Restored Ngau Tam Mei Landfill.
The storage and transport
of explosives for the Project have been assessed in a Quantitative Risk
Assessment. The criterion of the EIAO-TM
for Individual Risk is met. The assessment results show that the societal risk
lies within the As Low As Reasonably Practicable
(ALARP) region when compared to the criteria stipulated in Annex 4 of the
EIAO-TM. An ALARP assessment has been carried out by identifying all
practicable mitigation measures and assessing the cost effectiveness of each
measure in terms of the risk reduction achieved and the cost of implementing
the measures. The results show compliance
with the ALARP principles and Risk Guidelines (EIAO-TM Annex 4) provided
recommendations are implemented.
Operation
of the magazine site will remain the same as that for the current XRL
project. The magazine site is in a
remote area away from residential/ commercial/ industrial development to
minimize the risk.
In
this project three practical route options were considered for explosives
transport from the Tai
Lam Explosives Magazine Site to the three work areas using the public
roads. In two of the route options
(i.e. Route Options R1 and R3), the explosives
delivery truck will pass through Pok Oi Interchange.
Currently there is road improvement work at Pok Oi
Interchange which leads to serious traffic jam, thus temporary road diversion
and traffic control measures are enforced.
There is concern from Yuen Long District Council on use of Pok Oi Interchange by the explosives delivery truck during
the road improvement work, therefore one of the route options (i.e. Route
Option R2) will use Tong Yan San Tsuen Interchange and Yuen Long Road to avoid Pok Oi Interchange.
Risk
assessed in this study considered various population
which include passengers on the road vehicles, pedestrians on footpaths and
pavements next to delivery routes, and building occupants along the delivery
routes.
Feasibility
and minimum risk impact are considered to select the explosives delivery
routes:
·
At early stage of this project with road improvement
work at Pok Oi Interchange, Route Option R2 will be
used. Route Options R1 and R3 are not feasible.
·
After road improvement work at Pok
Oi Interchange is completed, all three routes will be available for use. The Route Option with minimum transport
risk, i.e. Route Option R1, will be used. Route Option R3 can only be used as a
contingency alternative route in the event that Route Option R1 is infeasible
due to road blockage by traffic accidents.
ALARP
assessment has been conducted to identify the potential practicable risk
mitigation measures using Cost Benefit Analysis, which includes
·
Need for a Tunnel and Proposed Alignment,
·
Magazine Requirement and Selection,
·
Use of alternative methods of construction,
·
Use of Alternative Routes,
·
Use of Different Explosive Types,
·
Use of Smaller Quantities of Explosives,
·
Safer Explosives Truck Design,
·
Lower Frequency of Explosives Transport,
·
Reduction of Accident Involvement Frequency, and
·
Reduction of Fire Involvement Frequency.
Practicable
risk mitigation measures identified in the ALARP assessment have been
recommended for implementation in this project.
In
addition, a number of recommendations have been made to ensure that the
requirements (including ALARP requirements) of the EIAO-TM will be met during
the construction period. Some
general recommendations have been made to minimise
the risks further and in accordance with best practices, for storage of
explosives in magazine store, transport of explosives as well as type of
explosives & their disposal.
The
key mitigation measure considered necessary for the Project concerns ecology (and landscape) and
states that the reinstatement planting at TLEM site that was to be carried out
by MTRC at the end of the XRL project in the approved XRL EIA report and
according to EP-349/2009/L, is now carried out by DHK upon completion of the
Project, expected to be in 2017.
Otherwise no adverse
residual environmental impacts are expected from the Project (including for
other elements of ecology, airbourne noise, air quality, waste, water quality or landscape
and visual) during operation or decommissioning, although during decommissioning proper site runoff
and soil erosion control measures in accordance with the guidelines stipulated in EPD’s Practice Note for Professional Persons on Construction
Site Drainage (ProPECC PN1/94) should be
implemented as good practice, as well as adopting general noise
control measures, as listed in Recommended
Clauses for Construction Contracts – Section 3 - Noise Control .
The
Hazard to Life Assessment for
the storage and transport of explosives from the TLEM site to the three
blasting worksites concluded that the societal risk of the storage facility and
selected transport routes lie within the ALARP region when compared to the
criteria stipulated in the EIAO-TM Annex
4, provided recommendations are followed.
An environmental monitoring
and audit (EM&A) programme will be implemented during the operation and
decommissioning of the Project and following decommissioning during
establishment of the reinstatement planting, to check effectiveness of the
recommended mitigation measures and compliance with relevant statutory
criteria.
Overall,
the EIA study predicts that the Project, with the implementation of the
mitigation measures, would be environmentally acceptable with no adverse
residual impacts on the population and environmentally sensitive
resources.