11                 conclusion

Air Quality

 Construction Phase

 

11.1            The potential dust impacts arising from the demolition and construction of the Project were assessed.  Results showed that the predicted air quality at the ASRs would comply with and far below the respective criteria with the implementation of dust suppression measures as stipulated in the Air Pollution Control (Construction Dust) Regulation.  Air monitoring and audit programme is proposed to ensure proper implementation of mitigation measures.

 

 Operation Phase

 

11.2            The potential impacts arising from chimney emissions from operation of the new cremators were assessed.  No exceedance of respective air quality criteria at the identified ASRs is predicted.  The air quality impact assessment results indicate that no adverse air quality impact would be expected during operation of the new cremators.

 

11.3            With the proper operation and maintenance of the new crematorium and APC equipment of the cremators, the residual air quality impact during the operation of the new crematorium is predicted to be insignificant.

Waste Management

 Construction Phase

 

11.4            With effective implementation of the mitigation measures, it is anticipated that the impacts on the environment and the potential impacts on the capacity of waste collection, transfer and disposal facilities will be insignificant. Extra demand for public fill areas and landfills would be minimal.  

 

11.5            The contaminated materials are expected to be concentrated around cremators, flues and chimney. After decommissioning and prior to demolition of the existing crematorium, further contamination investigation shall be carried out to confirm the quality and quantity of ash waste and building structures requiring treatment and disposal. The contaminated ash waste is recommended to be removed prior to any asbestos containing material in building structures.

 

 Operation Phase

 

11.6            The quantity of waste requiring disposal during the operation of the new crematorium will be minimal.

 

11.7            With effective implementation of the recommended mitigation measures, it is anticipated that the associated waste management implications from the operation of the new crematorium on the environment and the potential impacts on the capacity of waste collection, transfer and disposal facilities will be insignificant.

 

Land Contamination

 Construction Phase

 

11.8            Site investigation was undertaken for the fuel tank system and aerial deposition from stack emission for land contamination assessment. The result indicated that one soil sample (BH-1, 1.5 – 1.95m bcl) was found exceeding to the relevant RBRG for lead. The amount of contaminated soil required remediation is estimated to be around ~37m3.

 

11.9            Cement solidification/stabilization (CS/S) treatment is proposed for the remediation of ~37m3 soils contaminated with heavy metals in this Study. The treated soils have to meet both the universal treatment standards in the TCLP test and the unconfined compressive strength (UCS) test of not less than 1 MPa before backfilling on site.

 

11.10        Further site investigation in areas that are currently in use and cannot be accessed is required.  These areas include the trial pit for soil sampling underneath the pipeline and two cremation rooms. It is recommended that further site investigation shall be undertaken after decommissioning and prior to the demolition of the existing crematorium.

 

11.11        Findings of further site investigation will be presented in supplementary CAR and supplementary RAP shall be prepared, if required, for EPD endorsement prior to the commencement of any earthworks.

 

11.12        No significant residual land contamination impacts are predicted from the demolition of the existing crematorium and construction of the new crematorium provided that the recommended mitigation measures are properly implemented.   

 

 Operation Phase

 

11.13        As Towngas will be used as burning fuel instead of diesel in the new crematorium, possible leakage or spillage from the underground fuel tank and the pipeline system is eliminated. With the new design of cremators which is capable of meeting the newly revised requirements described in “A Guidance Note on the Best Practicable Means for Incinerators (Crematoria)” BPM12/2(06), it is anticipated that aerial deposition would not give rise to significant land contamination.

Visual Impact

 Construction Phase

 

11.14          Visual impact on VSRs R1, R2, GIC1 and OU1 would be substantial due to the close distance to the Project. However, such visual impact is temporary and can be minimised by decorative hoarding.

 

11.15        With implementation of mitigation measures during construction, there will still be some moderate adverse visual impact on the R1, R2, GIC1 and OU1 adjacent or close to the Project. Residual impacts on the rest of VSRs will be slight to insubstantial significance as further away from the Project areas.

 

 Operation Phase

 

11.16          Design approach and consideration will position cremator plant room and operation & maintenance supporting facilities on basement level to reduce building massing and height; a step down terrace elevation to match with steep terrain and create a smooth transition to the existing Garden of Remembrance.

 

11.17          The existing natural topography and dense vegetation of woodland have provided natural screening and blockage for most of the proposed above-ground structure except north-east face where the two chimney stacks will be located. Day 1 after the implementation of operation stage mitigation measures, there would still be moderate adverse visual impact on R1, R2 GIC1 and OU1; the rest of VSRs are slight and insubstantial. Trees will be planted within the site and works areas to compensate for the loss of the existing trees. Within 10 years all the proposed treatment will be in mature stage of the implementation of visual mitigation measures, therefore all the adverse impacts will be insubstantial. The architectural appearance of proposed crematorium will be aesthetically design to be compatible with adjacent landscape setting to enhance the overall outlook to minimise visual impact. Roof greening will be adopted for the provision of landscape amenity and character of remembrance. Landscape roof garden will enhance and embrace the amenity space with the existing Garden of Remembrance to strengthen the overall visual characters of the site. Therefore visual impact on VSRs R1, R2 GIC1 and OU1 will be slightly benefited from the new crematorium appearance.

Noise

 Construction Phase

 

11.18        This assessment has predicted the construction noise impacts of the Project during normal daytime working. The predicted unmitigated noise levels at representative NSRs will range from 60 to 79 dB(A) for Phase 1 and 61 to 81 dB(A) for Phase 2. With the use of quiet PME for excavator/loader, soil nailing drilling machine, rock dowel drilling machine, bulldozer, dump truck and crawler mounted rock drill, the noise levels at all representative NSRs would comply with the construction noise limit of 75 dB(A).

 

 Operation Phase

 

11.19        The noise impact associated with the operation of the Project was assessed. For newly proposed equipment under Phase 1 and Phase 2, while the predicted noise levels at SQ1 and SQ2 would exceed the daytime/evening planning noise criteria by 3 dB(A), the predicted noise levels at all representative NSRs would exceed the night-time planning noise criteria by 1 to 6 dB(A).

 

11.20        To mitigate the noise impact at the affected NSRs, 2.5m high noise barriers have been proposed to surround the radiators. Besides, the noise barrier would be lined with sound absorbing material at the surface of the barrier facing the noise source to further enhance the noise reduction effectiveness. With such noise barriers in place, the predicted noise levels at all representative NSRs would comply with both the daytime and night-time planning noise criteria. No residual operation noise impact arising from the Project is anticipated.    

 

11.21        For the concurrent operation of existing fixed plant and new fixed plant during T&C stage of Phase 1, the predicted cumulative noise levels at all representative NSRs would comply with the relevant daytime/evening ANL of 65 dB(A) with the 2.5m high noise barriers for the radiators in place.

 

Water Quality

Construction Phase

 

11.22        Water quality impacts from the land-based construction and demolition works can be controlled to acceptable levels by implementing the recommended mitigation measures.  No unacceptable water quality impacts will be expected from the land-based construction and demolition activities.

 

Operational Phase

 

11.23        No effluent will be discharged from the Air Pollution Control equipment in the new crematorium as “dry” process will be adopted. Sewage generated by visitors and workers, as well as wastewater from cleaning activities will be connected to the sewerage system. Sewerage impact assessment has been conducted for the Project. Assessment results indicated that the additional wastewater / sewage generated from the Project would not cause any adverse impacts to the existing sewerage systems. Hence, adverse water quality impact is not expected.

 

Overall Conclusion

11.24        This assessment has considered the environmental impacts from the demolition of the existing crematorium as well as the construction and operation of the new crematorium.

 

11.25        It has been assessed that the environmental impacts arising from the Project are either considered minimal or can be mitigated to an extent where the impacts on the sensitive receivers are acceptable.

 

11.26        No significant residual impacts are anticipated, provided that the recommended mitigation measures are properly implemented.

 

11.27        An EM&A programme is therefore recommended to ensure that the mitigation measures have been properly implemented and environmental quality has not been seriously affected throughout the Project.