3.                   ENVIRONMENTAL IMPACT ASSESSMENT

Introduction

3.1               An EIA Study in response to Study Brief No. ESB-125/2005 was conducted in accordance with the guidelines on assessment methodologies provided in the Technical Memorandum on Environmental Impact Assessment Process (EIAO-TM).  The general approach for the assessment included:

n                      Description of the environment and baseline conditions for the impact assessment

n                      Impact identification

n                      Impact prediction & evaluation

n                      Impact mitigation

3.2               Uncertainties in the assessment of impacts were considered when drawing conclusions from the assessment.  In carrying out the assessment, realistic worst case assumptions were made in order to provide a conservative assessment of environmental impacts.

3.3               The main findings of the EIA study are summarised below.

Description of the Assessment Area

3.4               The majority of the proposed works are located within the existing Ocean Park area at Aberdeen within the “Waterfront” (currently known as the Lowland) and the “Summit” (currently known as the Headland) areas.  The Park will also expand into part of the existing public bus terminus and part of the existing Hong Kong School of Motoring adjacent to the main entrance of the existing Ocean Park, and across a currently unused area at Nam Long Shan, adjacent to the existing Headland area.  Major land uses found in the vicinity of the lowland are residential (such as Shouson Hill) and Government/ Institutional/ Community uses (such as the Police Training School).  There are also industrial as well as residential uses to the west of the existing Headland. 

Results of Assessment

Noise

3.5               The assessment predicted that with the use of quieter equipment and movable noise barriers, construction noise levels at all representative noise sensitive receivers (NSRs) would comply with the relevant noise criteria. 

3.6               The potential road traffic noise impacts during the operation phase of the redevelopment were assessed for the worst-case traffic flows in Year 2026 (15 years after opening of the Project). Road traffic noise impacts due to the proposed redevelopment were assessed for both “with development” and “without development” scenarios for a representative weekday and Sunday. Modelling results indicated that the increase in traffic noise levels due to the proposed redevelopment would generally be less than 1dB(A).  Noise levels predicted for Police Training School (1-2/Fof NSR PTS1 and 1-4/F of NSR PTS2) would increase by more than 1 dB(A), but the noise levels at those locations would comply with the EIAO-TM noise criteria.  Thus, no mitigation measure would be needed and no adverse traffic noise impact from the traffic induced from the Project would be expected.

3.7               Cumulative impacts of fixed plant (including equipment/installations such as ventilation fan, rides, air conditioning units and parkwide public address system) and entertainment noise were predicted based on available design information.  Assessment results indicated that no adverse cumulative noise impact would be envisaged.  To ensure compliance with relevant noise criteria, it is recommended that noise monitoring be undertaken during the nighttime show performance at Aqua City.  A review of fixed noise source and entertainment noise impact based on detailed design available in later stage is recommended to verify EIA predictions.

Landscape and Visual

Landscape Impact

3.8               With the implementation of mitigation measures, the anticipated adverse landscape impacts due to the redevelopment of Ocean Park will be acceptable. Major impacts on landscape resources will result from the substantial excavation and construction of “The Summit”, which involves an extensive area of Nam Long Shan. With respect to the landscape character, the redevelopment will cause changes in all areas within the Park and Nam Long Shan. The extent of the excavation and the rest of the works during construction will be large.  Even with the implementation of mitigation measures, there will still be adverse impacts to the existing landscape characters.  After the construction phase, the landscape characters of most of the Park will be restored, except for the whole new character created in Nam Long Shan by substantial landform change and conversion to Park area.

Visual Impact

3.9               After the full implementation of mitigation measures, the anticipated adverse visual impact will be generally acceptable.  The substantial excavation and construction works of both “The Summit” and “The Waterfront” will induce moderate visual impacts for a number of sensitive receivers.  Once the construction completes, the impact to most receivers will become reduced and restricted to only those locations in close proximity to the Park.

3.10            Impact of day-time glare would be avoided through the adoption of suitable building forms and materials.  With careful consideration in the design stage and adoption where necessary of suitable design features, there would be no residual day-time glare impact. 

3.11            The assessment has identified that the existing Ocean Park and surroundings are at night generally influenced by many and various existing light sources, although the intensity diminishes towards certain areas such as “the Summit” area.  Night-time glare would be essentially “designed out” by carefully considering a reasonable level of functional and thematic lighting with due consideration of possible light pollution and night-time glare to the surroundings.  With careful consideration in the design stage and adoption where necessary of suitable design features, there would be no residual glare impact from night-time lighting.

Ecological

3.12            A literature review, a marine ecology survey and 6-month terrestrial ecological surveys covering both the wet and dry seasons were undertaken to establish the ecological profile of the Assessment Area.  Nine habitat types within the assessment area were described, of which the tall shrubland and subtidal habitat are considered to have moderate ecological value.  The freshwater habitats and rocky shore were of low to moderate value, and other habitats of low to very low value.

3.13            Eleven plant species of conservation interest were recorded from the Assessment Areas.  The recorded species are all relatively common in Hong Kong.  Several terrestrial faunal species of conservation interest were recorded in the Assessment Areas, comprising eleven bird, one reptile, and three mammal species.  Nineteen species of hard corals and nine species of soft (octocorals) were recorded during the surveys.  The hard corals are predominantly small in size with patchy distribution and most of them are common species. 

3.14            For the most part, impacts would be restricted to areas inside of the existing Ocean Park boundary, and therefore limited to relatively low ecological value developed areas, low shrubland and parkland & plantation.  These impacts are considered minor in scale.

3.15            Although the layout and construction methods have been considered to avoid impact to the plant species of conservation interest where possible, individuals of nine plant species of conservation interest could be directly affected by the proposed works, and potential impacts would require mitigation. 

3.16            Potential impact on the potential breeding habitat for Black Kites in the Headland Area has been avoided because site clearance would commence before the breeding season of Black Kite and there would not be any direct impact on nesting activities.  Existing man-made freshwater ponds, one located in Tai Shue Wan Area and another one in Lowland Area, would be preserved to avoid disturbance of the roosting site of birds such as Black-crowned Pond Heron.  Affected plant species of conservation interest would be transplanted where appropriate.

3.17            Tree survey would be conducted to identify any mature trees affected by the proposed works.  Felling of mature trees would be compensated by planting of standard or heavy standard trees.  Compensatory planting would be provided on at least a 1:1 ratio. 

3.18            The tall shrubland habitat affected by excavation in the Headland Area is considered of moderate ecological value.  The impact due to the loss of 4.8ha tall shrubland habitat will be mitigated through 6ha compensatory planting.

3.19            Any of the species potentially disturbed by construction phase activities would be likely to relocate to nearby areas further from the source of disturbance.  Alternative habitats are available in the remaining tall shrubland habitat as well as elsewhere nearby the Ocean Park site.  Minor indirect impacts to wildlife resulting from construction and operation phase disturbance were predicted. 

3.20            Loss of marine ecological resources is avoided as there would not be any marine-based construction works for this Project.  With the implementation of water quality mitigation measures and good site management practices, no adverse impact on coral communities would be anticipated during the construction and operation phases of the project.  Nevertheless, coral monitoring during construction phase is proposed as a precautionary measure.

3.21            In summary, with the implementation of the recommended mitigation measures, potential ecological impacts resulting from the Project were found to be minor and acceptable. Further operation of the Park would not result in substantial increases in direct and indirect ecological impacts, over and above existing impacts resulting from the current operation of the Park.

Waste Management

3.22            Waste types generated by the construction activities are likely to include construction and demolition material (from site formation, excavation and tunnelling works), general refuse from the workforce, and chemical waste from the maintenance of construction plant and equipment.  Provided that these wastes are handled, transported and disposed of using approved methods and that the recommended good site practices are strictly followed, adverse environmental impacts are not expected during the construction phase.

3.23            The main waste types to be generated during the park operations would be similar to the existing operation of the Park and would include general refuse and food and beverage waste, as well as some chemical waste, biological waste and the occasional animal carcass.  Based on the predicted increase in visitor and staff numbers following redevelopment of the Park, the quantity of general refuse and food and beverage waste has been estimated to increase by approximately 30% and would be met by a commensurate increase in the number of waste collection bins and collection points provided at the Park.  The handling, collection, transportation and disposal practices of the identified waste arisings would follow the existing arrangements currently in operation at the Park.

Land Contamination

3.24            An investigation of the historical/current land uses, including a desk-top review and site inspection, at the Hong Kong School of Motoring (HKSM), Citybus Depot (CBD) and existing Ocean Park has been carried out as initial part of the land contamination assessment. The results indicated that no contaminative land uses are identified before the operation of the HKSM, CBD and existing Ocean Park.

3.25            The concern of contamination at the HKSM and CBD arises from the presence of vehicle refuelling/ washing area, vehicle maintenance workshop and chemical waste storage area.  For the existing Ocean Park area, most of the potential contaminative workshops were maintained in good condition by good housekeeping. The ground was well paved without cracks or stains and therefore no sign of contamination was noted within the Park.

3.26            Two Contamination Assessment Plans (CAP) which detail the sampling locations and testing schedules of the site investigation (SI) have been prepared. A total of 20 sampling locations are proposed for the HKSM and CBD, with 10 sampling points at each site. Citybus Limited has given its consent to Ocean Park Corporation (OPC) to submit the CAP on their behalf. The CAP prepared for HKSM under this EIA is for illustrative purpose only. The party responsible for land contamination SI at the HKSM site in the future would need to separately submit a CAP for Environmental Protection Department (EPD)’s approval. 

3.27            For CBD site, the SI was conducted from 31 March to 3 April 2006. The results as presented in the CAR indicated that the concentration of most of the heavy metals in the soil samples are acceptably low except arsenic and tin at five specified locations. Considering that the elevated levels of heavy metals are found very localised in the fill materials, the source is probably not due to the past site activities/surface spillage and the level of materials would be kept untouched during the construction stage, direct impact to the construction workers would not be anticipated.

3.28            A further study, Toxicity Characteristic Leaching Procedure (TCLP) testing, will be conducted in order to determine the leachability (hence the toxic risk) of the soil with elevated level of metals at the CBD site. For a conservative approach, clean-up strategy is proposed for the soil contaminated with heavy metals with details in the Remediation Action Plan (RAP).

3.29            The soil with elevated level of arsenic/tin (~150 m3) is proposed to be excavated, treated on site using cement solidification/ stabilisation (CS/S) and backfilled to original position. The mixing procedure would be carried out within a skip or equivalent. Assuming a production rate of 30m3 per day (i.e. 6 skips per day & 5m3 per skip), about 1 month would be required to complete the whole CS/S process. Environmental impact related to contaminated land is considered minimal with implementation of the proposed mitigation measures. This proposed clean-up strategy may be reviewed should other site data (e.g. TCLP results) be available.

3.30            Elevated total petroleum hydrocarbon (TPH) concentrations above the B value of 1,000mg/kg were found in two sampling locations in the immediate vicinity of the underground refuelling tanks. Soil remediation at these locations is recommended with details in the RAP. The excavation of BH-2 is proposed to be down to 8m below grade.  The excavation of BH-6 and the remaining area around the tank is proposed to be down to 6m below grade which equates to maximum soil volume of about 150m3. Considering that the quantity of contaminated soil would be small (~150m3), such contaminated soils are proposed to be excavated and disposed of to landfill site.

3.31            For HKSM Site, in view of the current site condition observed from site inspection, information obtained from Fire Services Department (FSD)/Environmental Protection Department (EPD) without bulk spillage/ leakage and nature of business without heavy contaminative activities involved, only small-scale contamination caused by localised leakage/ spillage is likely to be encountered. Insurmountable impacts on the surrounding environment in respect of land contamination would therefore not be anticipated.

3.32            Based on professional judgement and experience gained from other similar projects involving leaks from underground storage tanks, the contamination would normally be found at the “smeared” zone (i.e. 1m below and above ground water table). The volume of the contaminated soil for excavation is estimated to be around 400m3. Nevertheless, without the benefit of detailed evidence gained from a SI, there is some uncertainty in this volume.

3.33            The SI for HKSM should be conducted as soon as possible after the site operation ceases. A CAR should be prepared to document the findings of the SI and identify any need for remediation. If land contamination is confirmed, a RAP should be drawn up to formulate necessary remedial measures. The subsequent CAR and RAP should be endorsed by EPD prior to implementation of any remedial works.

3.34            Different remediation options and associated treatment programme have been proposed based on the estimated quantity of contaminated soil and nature of possible contaminants. Both Tai Shue Wan and the open space near the existing Nam Long Shan rest garden are considered technically feasible for the proposed remediation works. The CS/S works for heavy metal contaminated soil is proposed to be carried out in the HKSM site if the soil volume is small. The biopile and/or CS/S treated soil will be re-used on site. Appropriate mitigation measures have been recommended to minimise environmental impacts during soil excavation, transportation and remediation. No adverse residual impact in respect of land contamination is anticipated if necessary remediation works are carried out in respect of any identified contaminated land. 

3.35            In the event that the current users or responsible parties of the HKSM Site do not fulfil its obligations to undertake a CAP, CAR or RAP or the necessary remediation to the satisfaction EPD, and the site handed-over to OPC is not totally cleaned (for technical or other reasons), then the whole HKSM site will initially be fenced off and the suspected contaminated area will be fully demarcated and isolated. The purpose of fencing the site is to restrict access to ensure there would be no risk to the general public.  Following this, OPC undertakes to carry out, to the extent outstanding, the site investigation. Such an undertaking does not relieve the existing users of their obligations to clean the site, nor does it in any way restrict OPC’s rights to recover the costs of carrying out the SI works from the responsible parties. 

3.36            Once the SI results are available, the potential contaminated area could be identified and the fenced-off area could be adjusted to isolate only the area of contamination. OPC would ensure that no work would be undertaken within the fenced off area. OPC would modify the design of the new entry plaza and access road so as to accommodate this fenced off area in its layout and to limit access to, as well as circulation around it.

3.37            OPC has confirmed that the space and time requirements for contamination investigation and/or treatment of contaminated soil can be accommodated in the overall design and redevelopment programme for Ocean Park. 

Air Quality

3.38            No adverse dust nuisance during the construction phase would be expected with the implementation of dust suppression measures stipulated in Air Pollution Control (Construction Dust) Regulation and good site practices.  A monitoring & audit programme is proposed to check whether the recommended mitigation measures are implemented effectively.

3.39            Additional traffic emissions resulting from the operation of the redeveloped Park would not pose adverse air quality impacts to the nearby air sensitive receivers.  The air quality at the representative air sensitive receivers is expected to be acceptable.

Water Quality

3.40            Potential impact to water quality during the construction phase could be avoided through implementing adequate control and mitigation measures on site runoff and drainage from the works areas.  Proper site management and good housekeeping practices would to ensure that construction wastes and other construction-related materials would not enter water bodies and the public drainage system.  Sewage effluent arising from the construction workforce would be managed through provision of portable toilets.  With the implementation of the recommended mitigation measures, the construction works for the Project would not result in unacceptable impacts on water quality. 

3.41            Additional type of operation discharge from the future operations at the redeveloped Park is not expected, and there would not be any additional discharges containing disinfectants/residual chemicals produced from the marine life keeping system aquariums and visitor attraction facilities.  Operational procedures to be adopted would avoid or minimise the risk of unacceptable water quality impact.  As such, it is expected that the operation of the redeveloped Park would not result in unacceptable impacts on water quality.  Upgrading of the existing foul sewerage system within the Park will be required to prevent sewage overflow and/or emergency bypass as a result of capacity constraint of the sewerage system. There is no proposal for sewage treatment and disposal within the redeveloped Park.

Sewerage and Sewage Treatment

3.42            The performance of the existing sewerage infrastructure was assessed using approved methods and flow factors.  The estimated peak flow was used in the hydraulic assessment of the existing Aberdeen Preliminary Treatment Works (PTW).  The performance assessment results under the peak flow condition identified 1520mm of surcharged sewers with diameters ranging from 225mm to 375mm.  Works to improve these surcharged sewers are needed. 

3.43            The Aberdeen PTW was assessed to be adequate to convey the total catchment flows under both Baseline and SIA Conditions under this Study. No overflow / bypass of sewage is anticipated.

Cultural Heritage

Archaeology

3.44            The archaeological potential for areas that would be impacted by the construction and operation of the proposed Ocean Park redevelopment, including the Hong Kong School of Motoring, and Lowland, Headland and the Tai Shue Wan area of the existing Ocean Park, was assessed.  The assessment concluded that the proposed Ocean Park redevelopment and operation would have no impact on areas of archaeological interest, except at the existing School of Motoring and City Bus Depot sites where the construction of the Entry Plaza and a section of Ocean Park Road are proposed in areas identified to have low archaeological potential.  Test pit excavations to verify the presence or absence of archaeological deposits shall be undertaken at these sites prior to the construction phase.  The scope of the Archaeological Investigation is to be agreed with Antiquities and Monuments Office (AMO) prior to commencement of the construction.

Built Heritage

3.45            Although there were no Declared Monuments or graded historical buildings in or within the vicinity of the Study Area, the village of Wong Chuk Hang San Wai, four former military bunkers on Nam Long Shan Road and a historical grave were identified as structures of potential historical value. 

3.46            The construction works associated with the proposed redevelopment would have no impacts on the recorded historical buildings in the Study Area given the large buffer distance.  The current project layout allows for the grave within the existing Ocean Park to be preserved in-situ and any future alterations should also allow for it to be preserved in situ. If any works are planned close to the grave, a one metre buffer zone should be provided around the grave, demarcated by a temporary fence. 


Hazard to Life

3.47            Explosives will be used for excavation of Nam Long Shan and for excavation of the funicular railway tunnel.  Therefore, Quantitative Risk Assessment (QRA) study for the explosives related activities for the Project has been carried out.  With the implementation of the recommended safeguards as well as the risk control measures, the risks comply with the Risk Guidelines as stipulated in the Annex 4 of the Technical Memorandum for Environmental Impact Assessment Process.