10.1
According to
the SI for land contamination assessment, the subject shipyard was found to be
contaminated with heavy metals, TPH, SVOCs and dioxins.
10.2
The volumes
of contaminated soils in Areas 1, 2 and 3 are estimated to be 10,231501559,000m3100m3, 3115,2505,000m3,
and 95612,600845000260m3 respectively. The contaminated soil will be excavated
and treated on site
for metal-contaminated soil or off- site at TKW for other types of
contaminated soil according to their nature of contamination. The
contamination level of groundwater was considered acceptable according to the
risk -based standard,, therefore no in situ nor off-site treatment of
groundwater is required. E except that there is a small
hot spot area which was shown to have notable free products..
10.3
Any
contaminated soils and
groundwater found within the site will be removed. Remediation
systems will be effectively mitigated to prevent any potential negative
impacts. No contaminated soil and
groundwater will remain after remediation to the agreed cleanup
standards. Free product encountered during excavation will be
bailed out as much as possible, and will be disposed of as chemical waste. As such, land contamination at CLS will not adversely
affect the Theme Park development and will not pose significant heath threat to
the future users of the site.
10.4
Compared to
the future land users, construction workers will be more exposed to the
contaminated material during excavation and remediation works. The principal exposure routes for
workers are ingestion, inhalation, and dermal contact. However, with the strict implementation
and enforcement of safety measures, no excessive health risk will be posed on
the workers.
10.5
The transport of
contaminated soil is covered under ecologicalwaste impactmanagement.
10.6
Upon completion of the
remediation works, all the contaminated soil excavated from the CLS will be decontaminated to the
relevant cleanup standards. With proper implementation
of proposed mitigation measures, there will be no adverse environmental impacts on site workers and other sensitive receivers.
10.7
Dust will be
generated during building
demolition,
slope improvement and remediation and decommissioning of CLS, handling of general contaminated
soil process at TKW and truck haulageCheoy Lee Shipyard. At ground level, tThe predicted hourly and
daily TSP concentrations at the worst affected elevation (1.5m above ground) are
in the range of 7734 – 19241
mg m-3
and 712
– 94108
mg m-3,
respectively. It has been
predicted that Penny’s Bay GTP at CLS and dockyard building at TKW will
receive higherst
hourly and daily TSP levels.
10.8
Cumulative
air quality impact from the decommissioning of CLS and other activities from
the construction of the theme park at Penny’s Bay were predicted. Maximum hourly and daily TSP
concentrations are predicted at Penny’s Bay GTP and are about 26654
mg m-3
and 12547
mg m-3,
respectively. Thus, exceedances of the
TSP criteria are not predicted.
10.9
Dioxins have
been measured at the burn pit areas of CLS. Modelling
results indicated that the impacts at the ASRs satisfy the hourly criteria with
the proposed excavation rates. The HPCL stipulated in the APCO would be exceeded if
excavation is conducted within 150 m
from the excavation pit. The
excavator rate should therefore be reduced when the excavation pit is close to
the sensitive receiver.
10.1 The predicted maximum
hourly and daily TSP concentrations are 87 mgm-3 and
81 mgm-3,
respectively, at the ASRs at To Kau Wan. As the air quality impacts at ASRs at To Kau Wan are
low and the criteria are satisfied, adverse air quality impacts on sensitive
receivers at both ground level and higher levels are therefore not expected.
10.10
TSP, TOC and,
TAPs including dioxins would be emitted from the off site treatment
facilities,area
at To Kau Wan, their air quality impacts would comply
with the air quality standards, with the control measures incorporated.
10.11
Air quality impacts associated with the
decommissioning of treatment facilities at TKW site will be low
and will complied with the air quality criteria.
10.12
The risk level associated with the operation of the
treatment facilities has been assessed to be insignificant, and comply with
international criteria.
Water
Quality Impact
10.1Groundwater at the demolition site is contaminated
with heavy metals. Thus, direct
discharge of groundwater collected from the dewatering process during
excavation of contaminated soil is not expected. If required, contaminated groundwater should be recharged
back into the ground within the shipyard site.
10.1Any seepage of contaminated groundwater from CLS
site into the adjacent drainage channel will be diluted by 104 times
prior to discharge into the marine water.
The water quality within the drainage channel will still comply with the
UK Water Quality Standards. In
addition, the existing seawall along the CLS site and the concrete wall of the
drainage channel will act as additional physical barriers to lower the seepage
of contaminated groundwater from the CLS site to the drainage channel. It is therefore considered that the
water quality of the identified water sensitive receivers in the vicinity of
the CLS site will comply with the relevant water quality guidelines.
10.1Any surface run-off and on-site discharge from the land based
demolition and construction activities and off-site
remediation will be readily controlled by good site management
practices and implementation of appropriate on-site measures. Therefore, no adverse water quality is
expected on the identified water quality sensitive receivers.
Waste Management
10.13
C&D wastes material will be
generated during the demolition of the shipyard facilities and the estimated quantity is
about . It
is estimated that about 10,000 m3 uncontaminated
andof which 1,000 m3 is contaminated C&D
wastes will be produced.
In addition, about 1,000 tonnes of steel and 5,000 m3 of
general refuse will also be generated. A top-down,
non-blasting and “selective demolition” approach is selected. It is considered that
adverse waste impacts will not be generated provided that good site practices
and waste handling recommended in Sections 6.69 to 6.107procedures are strictly
followed.
10.14
During slope
improvement phase, around 40,000m3 uncontaminated soil and 2,100m3 uncontaminated rock will
be generated during excavation and soil nailing. Such
excavated material will be reused/ recycled as much as practical or. Excavated material will be reused/ recycled within CLS as much as
practical and the surplus will
be transported for public fillto public filling areas (PFAs) for public fill or restoring
CLS. As such, no
residue waste impact is anticipated.
10.15
During remediation, about
39,000m3 contaminated material will be excavated from Cheoy Lee Shipyard and will
be transported to To Kau Wan for off-site treatment whereas 48,000m3 metal-contaminated soil will be
treated on-site at CLS. Environmental and safety measures have
been recommended to minimise secondary environmental impacts and health risks
during collection and transportation of contaminated soils from CLS to
TKW. After both on-site and
off-site treatment, around 100,000m3 clean inert materials suitable
for public filling will be generated.
The condensate of around 600m3 as the end product of the
treatment and other chemical wastes will be collected and disposed of at the
Chemical Waste Treatment CentreDuring remediation, about 135,000 m3 of soil contaminated with heavy
metals, PAHs and dixoins will be excavated from Cheoy
Lee Shipyard. The
contaminated soil will be transported to To Kau Wan for off-site
treatment. Environmental and
safety measures have been recommended to minimise secondary environmental
impacts and health risks during collection and transportation of contaminated
soils from CLS to TKW. Most of theAll soils after
treatment will turn to clean inert materials suitable for public filling. The condensate as the end product of
the treatment and other chemical wastes will be collected and disposed of at
the Chemical Waste Treatment Centre. Thus, no residual waste impact and health risk concerns are
expected.
10.16 During decommissioning of TKW, around 5,000m3 C&D material and 500 tonnes steel will be generated. C&D
material will be transported to PFAs and metal will be recycled, therefore, no residue impact is
envisaged.
10.17
The overall total of C&D
material to be generated by this Project is estimated around 0.4Mm3. The C&D material will be reused and
recycled as far as practicable in the land
formation works within CLS site so as to minimise the amount of C&D material to be disposed of at PFAs.
10.18 Incident rate of road accidents for transportation of waste has been estimated to be acceptably low. Notwithstanding
this, mitigation measures have been
proposed to minimise the impact of spillage of waste during transit.
Water Quality
Impact
10.19
Groundwater Heavy metals with levels
higher than the screening levels for ariskt assessmentContaminants with levels higher
than the discharge standards as stipulated in the TM-ES theare found in groundwater at the CLSdemolition site is contaminated
with heavy metals.
Thus, direct discharge of groundwater collected from the dewatering
process during excavation of contaminated soil shall is not be allowedexpected. Where necessary, If required, contaminated groundwater should be recharged back into the
ground within the CLSshipyard site.
10.20
Any seepage of contaminated
groundwater from CLS site into the adjacent drainage channel will be diluted by
88 times prior to discharge into the marine water. The water quality within the drainage channel will still
comply with the UK Water Quality Standards. In addition, the high installation level of the drainage channel
than the watertable and
existing
seawall along the CLS site and the
concrete channel
wall of the drainage channel will will act as additional physical barriers to prevent CLS lower the seepage of
contaminated groundwater from from seeping to the the CLS site to the drainage channel. It is therefore considered that the water quality of the
identified water sensitive receivers in the vicinity of the CLS site will
comply with the relevant water quality guidelines. The
remediation of CLS site will have an overall environmental benefit where after excavating CLS soils for treatment, the
contamination source will be removed and stopped from polluting the
groundwater.
10.21
Any surface run-off and on-site discharge from
the CLS site, slope work construction site and treatment site at TKW will be
readily controlled by good site management practices and implementation of
appropriate on-site measures. For potentially contaminated effluents, such as plant leachate,
runoff from the thermal desorption plant, wheel wash water and decontamination
water, centralised wastewater treatment units shall be provided at each of the
Project site to the get rid of the contaminant from the effluent before being discharged. Therefore, no adverse water
quality is expected on the identified water quality sensitive receivers.
10.22
The main
potential ecological impacts resulting from the project were identified as:
· Direct impacts to tall shrub/freshwater wetland
habitats and associated rare/restricted and protected plant
species near MTHS;
·Direct impacts to
freshwater wetland habitats and associated rare/restricted and protected plant
species near CLS;
· Direct impacts to Rice Fish habitats
and potentially Rice Fish populations;
·Impacts to marine
organisms if the transported wastes are spilled into the sea
10.23 Measures to mitigate these impacts toupon ecologically sensitive receivers are detailed in S76section 8. restricted/rare/, and further
contingency plans are given in Appendices 8A and 8B.With the successful
implementation of mitigation measures, residual impacts arising from the
project will be ecologically acceptable.
·Measures to mitigate theseIndirect
impacts to potential Egretry at To Kau Wan.
10.1Mitigation impacts, and further contingency
plans are given in Appendices 8A and 8B
measures are recommended in Section 8.8. With the proposedsuccessful implementation of mitigation
measures in place, residual impacts arising from
the project will be minimal and ecologically
acceptable.
10.24
The
archaeological survey of CLS revealed that the area has high archaeological
values. Many artifacts of different periods, including the Late Neolithic
period, Bronze Age, Tang Dynasty, Song Dynasty, Ming Dynasty and Ching Dynasty
have been recovered in the three demarcated zones along the ancient coastal
area. As Penny’s Bay is blocked
by the surrounding hills and is remote from the city centre, the cultural
heritage would not be damaged easily.
The recovered cultural remains therefore have high archaeological value.
10.25
Infrastructure
works at the three democratic archaeological zones shall be avoided to
ensure the potential impact to any surviving archaeological remains is kept in
an absolute minimum. The CLS have
been contaminated with the shipyard activities, and decontamination works are
required. The potential Filling
at the archaeological potential site where are not subject
to rescue excavation shall be covered by impermeable sheeting plastic sheetsbefore filling. Detailed design of filling work or
ground level adjustment work should consider diversion of site runoff to
prevent any waterlogged conditions. For areas where preservation in situ is not
possible, the
impact on the heritage resources should be mitigated by rescue excavation. All rescue works have to be completed
prior to the decontaminated works of CLS. Decontamination works such as excavation will unavoidable ineritably damage
the archaeological deposits and preservation in situ is therefore not
feasible. The archaeological
deposits at the three zones at CLS shall therefore be mitigated by rescue
excavation.