11                        Conclusions and Recommendations

11.1                   Introduction

11.1.1              Environmental impact assessments for the comprehensive development at Yau Tong Bay are conducted under the requirement of the Study Brief No. ESB-0028/1999.  The key environmental issues involve air quality, noise, water quality, waste management, sewerage and sewage treatment implications, and visual and landscape impacts.  Major findings and the recommendations are summarized in the following sections.

11.2                   Major Findings of the Engineering Feasibility Study for the Comprehensive Development at Yau Tong Bay

Air Quality

Air Quality Impact Assessment

11.2.1              An Air Quality Impact Assessment has been conducted to quantitatively assess the emission impacts from industrial stack sources and vehicular sources from both road network options. Portal and ventilation shaft emissions from the Eastern Harbour Crossing (EHC) Tunnel, and their cumulative impact upon the development were also assessed. For the Tunnel Option for WCR, the portal and ventilation shaft emissions from the tunnel were incorporated into the assessment. Regarding the temporary sewage retention tank within the site, its potential odorous emission was also considered.

11.2.2              Sulphur Dioxide (SO2), Nitrogen Dioxide (NO2) and Respirable Suspended Particulate (RSP) have been chosen as the representative pollutants for assessment of air quality impact from industrial and vehicular emissions.

Industrial Emission Assessment

11.2.3              Due to the close vicinity of the proposed development and the existing Yau Tong industrial area, industrial emission from stacks sources in the industrial area were identified as the major air quality impact upon the development. Stack sources within 1km radius distance from the subject site were included in the assessment.

11.2.4              Sulphur dioxide was selected as the reference pollutant for the industrial emission impact assessment. Air quality standards for sulphur dioxide as stipulated in the Air Quality Objective (AQO) were applied as the assessment criteria for the assessment.

11.2.5              Information on all the identified stack sources were obtained from EPD. Sulphur dioxide concentration at the proposed development, were predicted with computer modelling.

11.2.6              Results of the industrial air quality impact assessment indicate that air quality impact on the proposed development from nearby industrial emission is likely to be acceptable and comply with the AQO.

11.2.7              No insurmountable construction dust impact is anticipated if proper dust suppression measures and monitoring are carried out by the contractors.

11.2.8              Assessments on I/R interface have indicated no adverse air quality impact is anticipated.

Vehicular Emission Impact

11.2.9              Existing and planned road networks in the Yau Tong area were included in the calculation, including the proposed extension of the Ko Fai Road to the west of the site. In addition, portal emissions and ventilation exhausts of the Eastern Harbour Crossing and the tunnel in the tunnel option were also incorporated in the assessment.

11.2.10          Air quality impacts were expressed in terms of the cumulative impacts arising from open road traffics, portal emissions and ventilation exhausts of the Eastern Harbour Crossing, the proposed tunnel for WCR, industrial emissions, as well as the background pollutant concentrations for each parameter. Results indicate that 1-hour and 24-hour NO2, and 24-hours RSP levels shall comply with the relevant AQOs at all air sensitive receivers of the proposed development in both road network options considered.

Odour Impact from Temporary Sewage Retention Tank

11.2.11          An underground and totally enclosed temporary retention tank with an effective volume of 2,712 m3 will be built at the site to serve the phases of development which come on-line after 2011 in the event that the KTPTW is overloaded after 2011.

11.2.1              A quantitative prediction of the odour impact from the temporary sewage retention tank upon the proposed development at the site was conducted. With the fully enclose sub-surface design of the temporary retention tank and maximum separation provided, the temporary retention tank shall not impose unacceptable odour impact upon the nearby sensitive receiver.


Construction Phase

11.2.2              A construction noise impact assessment has been undertaken for the nearby NSRs due to the construction of the Development. Unmitigated construction noise impacts at some NSRs are predicted to exceed the daytime noise limits established under the EIAO-TM. Mitigation measures have been designed to control construction noise impacts. The measures include the scheduling of work, use of quiet plants and movable noise barriers.

11.2.3              With the implementation of the above mitigation measures, noise impacts at the NSRs will comply with the statutory noise criteria. Regular monitoring of construction noise at representative NSRs is recommended to ensure that the NSRs will not be adversely affected by the construction noise.

Operational Phase

11.2.4              Road traffic noise impacts from the main roads in the vicinity are the major concern. To minimize the road traffic noise impact, the Development has adopted adequate noise mitigation measures including minimum 30m setback of buildings from Ko Fai Road, large buffer zone with promenade between Western Coast Road (Coastal Option) and the western residential towers, provision of 5m high podium edge noise barriers facing Ko Fai Road and 5m high noise barriers along Cha Kwo Ling Road and, location of office towers and commercial buildings to protect the residential towers.

11.2.5              Based on the predicted Year 2030 traffic forecast for the WCR Coastal and Tunnel Options, the predicted road traffic noise levels at the majority of the noise sensitive receivers are within the stipulated noise criterion of 70dB(A).  Only a minority (within 2%) of the residential flats of the 6 development options and 2 options of Refined Scheme will be subject to noise exceeding the 70dB(A) noise criteria. The schools of the Development will be subject to road traffic noise levels in the range of 37 - 74dB(A) with some rooms exceeding the stipulated 65dB(A) noise criteria.

11.2.6              As a last resort, it has been recommended that window type I glazing and air-conditioners will be provided to all affected residential flats and affected noise sensitive rooms of the schools.

11.2.7              With the implementation of the above mitigation measures, the noise impact will be adequately alleviated by the planned noise mitigation works to protect the towers of the development for all 8 development scenarios.

Water Quality

Construction Phase

11.2.8              During construction phase of the new development, the nearby water environment is potentially affected by:

·       Construction site runoff;

·       Wastewater arising from workforce; and

·       Accidental spillage of chemical waste from general site activities.

11.2.9              Unacceptable construction phase water impacts are not expected provided that proper mitigation measures and good site practices are implemented.  It is recommended that the good site practices outlined in ProPECC PN 1/94 “Construction Site Drainage" should be followed in order to minimize surface runoff and erosion, and also to retain and reduce any pollutants prior to discharge.  Provision and proper maintenance of site facilities for sewage disposal, spillage retention and chemical waste disposal are also required.

Operational Phase

Sewerage Impact

11.2.10          It is proposed that future sewage generated from Yau Tong Bay Development (YTBD) will be discharged to the Harbour Area Treatment Scheme (HATS) system for treatment at Stonecutter Island Sewage Treatment Plant via the HATS tunnel and the Kwun Tong Preliminary Treatment Works (KTPTW).  The KTPTW will have sufficient capacity to handle the additional flow from the development until 2011, whereas the HATS tunnel will become under-capacity by 2011.  A mitigation/contingency measure in the form of an on-site retention tank will be provided for the phases of development which come on-line after 2011 in the event that the KTPTW is overloaded after 2011, ensuring that the peak flow to the KTPTW is not increased.

11.2.11          The solution to the potential shortfall to the HATS tunnel and the need of upgrading the KTPTW will be investigated in detail under the further studies, including the upcoming ‘Environmental and Engineering Feasibility Assessment Studies’, recommended by the International Review Panel (IRP).

11.2.12          The potential water quality impact of an emergency discharge from the Yau Tong Sewage Pumping Station on the potential site proposed under the YTB Reclamation (Full Reclamation option) for the potential future reprovisioning of the Cha Kwo Ling salt water pumping station (CKLSPS) has been assessed.  The model results indicated that the depth averaged water quality in terms of BOD5, SS and ammoniacal nitrogen is expected to meet the WSD standards at the potentially reprovisioned CKLSPS; however, the E. coli standard will be exceeded.  The sewage plume is shown to attach to the shoreline and is buoyant at the surface with a thickness of less than 0.4m.  To avoid abstracting the sewage plume water, it is recommended that the future reprovisioned CKLSPS intake should be located below -2.0 mPD.  The intake water would then be expected to comply with the WSD water quality standards. The optimal intake configuration should be reviewed and decided at the detailed design stage.

Polluted Stormwater Impact

11.2.13          The cumulative effect of future polluted stormwater discharges from the nearby Yau Tong area, including the proposed YTB development, and the Kwun Tong Nullah may affect the nearby salt water intakes of the CKLSPS and Yau Tong saltwater pumping station (YTSPS), as well as the water quality of Victoria Harbour.  In addition, as the water flow under the proposed concrete decking to be built over the existing submarine pipelines near the northern part of YTB may be relatively low, polluted stormwater discharges may accumulate and cause deterioration in local water quality. 

11.2.14          Modelling results show that no unacceptable water quality impact in Victoria Harbour and, in particular, at the existing and potentially reprovisioned CKLSPS, under the YTB reclamation (Full Reclamation option), and the reprovisioned YTSPS, under the WCR-Coastal option reclamation, would be expected from polluted stormwater discharges.  As a result of tidal flushing, unacceptable water quality is also not anticipated under the proposed concrete decking.  Since the proposed concrete decking under the Minimized Reclamation will be reduced in size and is more exposed to the tidal flow in Victoria Harbour, the water quality under the concrete decking is expected to be better than that for the Full Reclamation option.  Hence, it is concluded that reprovisioning of the CKLSPS will not be required under the YTB reclamation (Full or Minimized Reclamation options).

11.2.15          It is recommended that silt traps or sedimentation tanks should be provided for urban run-off generated at the proposed development to minimise the potential pollution load to Victoria Harbour.

Waste Management

Construction Phase

11.2.16          During the construction phase, wastes generated by construction works are likely to include general site wastes, workforce wastes, maintenance wastes, and construction and demolition material.  Chemical waste produced from the construction activities should be handled according to the Code of Practice on the Packaging, Labelling and Storage of Chemical Wastes and disposed of by a licenced contractor.  These waste arisings are not expected to generate significant waste management related impacts, provided that the recommended mitigation measures are implemented and good site practices are adhered to.

Operational Phase

11.2.17          The estimated quantity of wastes generated from the proposed future development for the four development options in 2016 will be around 78,921 kg/day, of which 45,240 kg/day will be from residential sector and 33,681 kg/day from the commercial/industrial sector.  Refuse collection chambers will be provided for the residential development as well as the office/retail development.

Sewerage and Sewage Treatment Implications

Construction Phase

11.2.18          During the construction phase, a sewerage impact would be envisaged due to the sewage generated from the workforce.  However, with the provision of temporary latrines in the form of dry type portable toilets which are regularly desludged off-site, this impact can be mitigated.

Operational Phase

11.2.19          During the operational phase, sewage generated from the proposed population in-take in YTBD will be discharged to the HATS system via the KTPTW and the HATS tunnel.  The KTPTW will have sufficient capacity to handle the additional flow from the development until 2011, whereas the HATS tunnel will become under-capacity by 2011 at least.  A mitigation/contingency measure in the form of an on-site retention tanks is proposed for the phases of the development which come on-line after 2011, in the event that the KTPTW is overloaded after 2011.  The solution to the potential shortfall to the HATS tunnel and the need of upgrading KTPTW will be investigated in detail under the further studies, including the ‘Environmental and Engineering Feasibility Assessment Studies’, recommended by the IRP.

11.2.20          The YTPS and the associated rising main will have sufficient capacity to accommodate the additional flow from YTBD.  However, if an additional rising main is provided by the Government for standby capacity as recommended in the RECKSMP, agreement between Main Wealth Development Limited and the Government will be required for a sewerage reserve through the development site.

11.2.21          As the capacity of the local sewers downstream of the discharge point for YTBD will be adequate for accommodating the flow from the development, no upgrading works will be required.

Mitigation/Contingency Measure

11.2.22          An on-site retention tank is proposed as a mitigation/contingency measure to attenuate the sewage flow generated by the population in-take in YTBD after 2011 in the event that there is no spare capacity at the KTPTW.  The on-site retention tank is a holding facility which will store the additional sewage generated by the subsequent phases of development in YTBD after 2011 during the peak hours and discharge it during the off-peak hours of the day to ensure that the peak flow to the KTPTW is not increased.  However, the necessity and the exact size of the retention tank should be reviewed during the detailed design stage when the need and the programme of upgrading KTPTW from findings of further studies, including the ‘Environmental and Engineering Feasibility Assessment Studies’, as well as the development schedule of YTBD and other developments within the catchment are confirmed.

Visual and Landscape Impact

11.2.23          The quality of the existing landscape and the reclaimed land is generally poor.  There is insufficient open space within the area, and the access to waterfront is blocked by the previous shipyard, timberyard and open storage areas.

11.2.24          The mitigation measures proposed will minimize the potential visual and landscape impact, although, the effect during the construction phase is limited.

11.2.25          The construction activities will have low negative impact to the landscape resource and landscape character, and the impact is temporary only.

11.2.26          The extent of visual impact to adjacent lots will depend on the construction programme of these lots.  In general, Yau Tong Estate Redevelopment will be completed and occupied by resident during construction phase of the project, while resident for EHC site will move in during the construction phase of Yau Tong Bay Comprehensive Development.

11.2.27          The construction activities will have significant negative visual impact to some resident of Yau Tong Estate Redevelopment and EHC site, while the impact to the industrial workers at Ko Fai Road will be low. The visual impact to the resident at Sceneway Garden, Lam Tin Estate, Ping Tin Estate, Kwong Tin Estate, Hong Nga Court, Hong Pak Court, Hong Shui Court, Ko Chun Estate and Ko Yee Estate at mid level of Chiu Keng Wen Shan are considered as moderate negative to low as their view are toward the site will be blocked by future residential towers of EHC site Development and the Yau Tong Estate Redevelopment.  All these negative impacts are temporary during the construction phase.

11.2.28          During the operational phase, the 70,000m2 landscape garden together with the 20m wide promenade will formed positive impact to the environment as a whole, and the new residential buildings and office tower will enhance the image of Yau Tong Area.

11.2.29          Consider the urbanization of Yau Tong area for more residential and commercial development and improvement of traffic by the new Yau Tong MTR station, the proposed comprehensive development is considered compatible with the environment and will bend in well with its new context.

11.2.30          According to the Master Layout Plan of proposed Comprehensive Development at Yau Tong Bay, the visual impact of the proposed development to the visual sensitive receivers at the adjacent sites like Cha Kwo Ling Kaolin Mine Site, EHC Site, Yau Tong Estate Redevelopment have been minimized through careful disposition of residential towers and office tower so that these towers are spatially further away from these sensitive receivers.

11.2.31          Due to close proximity of the office tower at Cha Kwo Ling Road, there will still be high negative visual impact to some of the future resident of EHC site Phase 2 & 3 whom have a view directly toward the office tower.  While the visual impact to the other future resident of Cha Kwo Ling Kaolin Mine site, EHC site, and Yau Tong Estate Redevelopment and industrial workers at Ko Fai Road will be generally low negative.

11.2.32          The ridgeline Kowloon Hill between Black Hill and Chiu Keng Wan Shan will be breached by the high rise residential towers of Cha Kwo Ling Kaolin Mine Site Development, EHC site Development, Yau Tong Estate Redevelopment, Ko Chiu Road Estate Development and Lei Yue Mun Development, and the proposed comprehensive development at Yau Tong Bay will worsen the situation as the office tower and part of the residential towers will also breach the ridgeline.  The proposed stepping of residential towers from waterfront towards inland will help to minimize the adverse visual impact.

11.2.33          Based on the above study, it is noted that there will be some adverse landscape and visual impact due to the proposed comprehensive development during construction and operation stage, however, such adverse effect can be reduced or offset to large extent by the specific measures, and the overall landscape and visual impact is considered acceptable with mitigation measures.

11.3                   Overall Conclusion

11.3.1              The existing Yau Tong Bay is characterised by the old and obsolete industrial buildings which are considered to be the potential pollution sources.  Implementation of the proposed comprehensive development at Yau Tong Bay will remove the sources of pollution and nuisance, such as air, noise and water pollution emitters from the industrial operations to the nearby residents and the students of schools and will contribute environmental upgrading of the waterfront.

11.3.2              The Central and East Kowloon Development Study revealed a finding that there is a general shortage of the open space and inadequate provision of school facilities in Kwun Tong area.  Yau Tong Bay Development, if implemented, can provide an opportunity to relief the pressure arising from these shortcomings on the community and also the government.

11.3.3              The present EIA study for the comprehensive development at Yau Tong Bay indicated that there would be no insurmountable environmental impact arising from the development in YTB even the impacts generated from the I/R interface problem can be reduced to an acceptable level, provided that the recommended mitigation measures for the identified adverse impacts during the construction and operation phases are implemented.  Environmental monitoring and auditing are required to verify the efficacy of the proposed mitigation measures and to ensure that the adverse impacts are minimized and the relevant standards are complied with at all times.

11.3.4              On the contrary, should the project of Yau Tong Bay Development fail to proceed due to whatever reason, all existing marine lots on the bay will have no alternative but to continue with the offensive uses.  If it were the case, the nuisance created by the industrial operations on the marine lots to the surrounding residential development and schools under construction or planning along Cha Kwo Ling Road would be another environmental problem for these developments.