13                CONCLUSION

 

Introduction

 

13.1          This EIA Report has provided an assessment of the potential environmental impacts associated with the construction and operation phases of the proposed Project, “Improvements to San Tin Interchange”. 

 

13.2          Specific mitigation measure requirements for the Project, as well as environmental monitoring and auditing procedures, have been developed during the assessment of the proposed road scheme.  The Implementation Schedules of the recommendations are presented in Section 14.  The principal findings of this Report are summarized below.

 

Noise Impact

 

Construction Phase

 

13.3          Noise impact associated with the construction activities of the Project has been assessed.  The assessment results indicate that the construction noise levels at the NSRs of village houses near San Tin Highway and Kwu Tung Road and Tun Yu School would exceed the EIAO-TM noise criterion if no mitigation is applied.  Hence, noise mitigation measures would be required to abate the potential construction noise impact, including good site practices, quiet equipment and movable noise barriers.  With the adoption of the quiet equipment and movable noise barriers, all NSRs would be protected against adverse noise impacts from the construction of the Project.

 

Operational Phase

 

13.4          Potential road traffic noise impact associated with the Project has been assessed for the maximum traffic flows within 15 years from the start of the Project in operation.  With the implementation of the recommended noise barrier, no adverse noise impact on the existing NSRs from the proposed slip roads and the proposed section of Castle Peak Road to be widened (new roads) would be anticipated.  It was estimated that 4 existing residential dwellings would benefit from the proposed noise barrier by 2-4dB(A) noise reduction. 

 

13.5          Owing to the high noise levels from traffic along the existing roads such as San Tin Highway, Fanling Highway, Castle Peak Road, most of the existing NSRs would be exposed to overall traffic noise levels exceeding the EIAO-TM noise criteria.   The residual impacts have been assessed against the noise insulation criteria.  No existing NSRs would meet the noise insulation criteria and hence indirect technical remedies in the form of window insulation and air-conditioning would not be required.

 

13.6          With respect to the future/planned NSRs, the assessment indicated that traffic noise impact from the new roads would be well below the EIAO-TM noise criterion and contribute negligible noise increase to the overall noise levels with the implementation of the recommended noise mitigation measures.  No adverse noise impact from the proposed slip roads and the proposed section of Castle Peak Road to be widened would be anticipated. 

 

 

Air Quality Impact

 

13.7          With the incorporation of dust control measures stipulated in the Air Pollution Control (Construction Dust) Regulation, the air modeling results showed that the TSP level at the ASRs would be within the acceptable limits.  To ensure that the dust control measures are properly implemented, weekly site auditing is recommended during the construction of the Project.

 

13.8          Vehicle exhaust emissions would be the major pollution sources during operation of the Project.  Air quality modeling has been conducted to assess the impacts from the Project and surrounding road networks.  Modelling results indicated that no exceedance of the air quality objectives was predicted for the assessed air pollutants at the representative ASRs.

 

Water Quality Impact

 

13.9          The key issue in terms of water quality would be related to site formation and foundation works for the construction phase of the proposed road improvement works.  There are no fishponds located within close proximity of the proposed slip roads.  The nearest identified water bodies are existing nullahs running parallel to Castle Peak Road – Chau Tau and San Sham Road.  Potential sources of water quality impact comprise construction site runoff and drainage; debris, refuse and liquid spillages from general construction activities; and sewage effluents from the construction workforce.  Minimisation of water quality deterioration could be achieved through implementing adequate mitigation measures such as control measures on the runoff and drainage from the works areas to minimise construction run-off.  Proper site management and good housekeeping practices would also be required to ensure that construction wastes and materials would not enter the nearby nullahs.  Sewage effluent arising from the construction workforce would also require appropriate treatment through provision of portable toilets.

 

13.10      As such, with the implementation of these recommended mitigation measures, the construction works for the proposed road improvement works would not be anticipated to result in unacceptable impacts on water quality.  Site inspections should be undertaken routinely to inspect the construction activities and works areas in order to ensure the recommended mitigation measures are properly implemented.

 

Waste Management Implications

 

13.11      Wastes generated by the construction activities for the slip roads include C&D materials from the foundation works, general refuse from the workforce and chemical waste from any maintenance of construction plant and equipment.  Provided that these identified waste arisings are to be handled, transported and disposed of using the recommended methods and that good site practices are to be strictly followed, adverse environmental impacts are not anticipated during the construction works.

 

13.12      Waste management will be the contractor’s responsibility to ensure that all wastes produced during the construction of the Project are handled, stored and disposed of in accordance with good waste management practices and EPD’s regulations and requirements.  The recommended mitigation measures shall form the basis of the site Waste Management Plan to be developed by the Contractor at the commencement of the construction phase. 

 

Ecological Impact

 

13.13      An extensive literature review supplemented by a specific 6-month ecological survey was undertaken to establish the ecological profile of the Assessment Area.

 

13.14      The Assessment Area included several areas (Conservation Area, Wetland Conservation Area, Wetland Buffer Area, Wetland Enhancement Area) of recognized conservation interest. These areas have been designated largely to protect high ecological value wetland habitats to the north and northwest of the proposed works areas.

 

13.15      Eleven major habitat types were identified within the Assessment Area, comprising active fishponds, abandoned areas, plantation, developed areas, village/orchard, fung shui woodland, secondary woodland, active agricultural land, abandoned agricultural land, shrubland/grassland mosaic and nullahs/drainage ditches. Most habitats were considered to be of low or low-moderate ecological value. No plant species of conservation interest were found in the Assessment Area.

 

13.16      Eleven birds of conservation interest were recorded in the Assessment Area, although none were recorded in the proposed development area. No other fauna of conservation interest were recorded in the Assessment Area.

 

13.17      Residual impacts resulting from this Project would be limited to the direct loss of small areas of low ecological value, disturbed habitats, increased disturbance in the Assessment Area resulting from traffic utilizing the new development, and shading of the EMDC grasscrete lining following link bridge construction.

 

13.18      Overall potential ecological impacts resulting from the Project were found to be minor and acceptable.

 

Fisheries Impact

 

13.19      A review of the relevant literature and supplementary field visits were conducted. This established that the Assessment Area had only a very small area (approximately 1 ha) of active fish pond, none of which was located along or in close proximity to the proposed slip roads.

 

13.20      According to the assessment, none of the fish ponds would be directly lost or indirectly affected by the Project and so there would be no impact to pond aquaculture fisheries resources or operations. From the fisheries perspective, the Project would not give rise to unacceptable impacts. Aquaculturists were not expected to be affected by the proposed works.

 

Cultural Heritage Impact

 

13.21      The Study Area was determined to not contain any archaeological sites or areas of archaeological potential.

 

13.22      The impact assessment showed that there would be no adverse impacts to any of the recorded built heritage features, therefore, no mitigation measures would be required.  The impact assessment showed that there would be no adverse impacts to any of the recorded graves, therefore, no mitigation measures would be required.  No cultural and historical landscape features were identified in the Study Area.

 

Landscape and Visual Impact

 

13.23      The conclusions of the landscape and visual impact assessment are as follows:

 

·              Majority of the baseline condition within the study area comprises traffic corridor, industrial/ utility uses are considered to be of medium to low quality and sensitivity to change.  The wooded slope to the south of the study area with high in landscape quality and sensitivity to change will not be affected by the proposed improvement works.

·              No area of the improvement works would fall within the landscape zoning context such as country park, open space, greenbelt or conservation area.  This project is compatible with the government’s statutory planning framework in terms of landscape conservation.

·              This project would result in the loss of approx. 2775sq.m of vehicle corridor (LE2), approx. 0.9ha of roadside tree (LE3) and approx. 0.6ha of industrial/utility (LE5).238 nos. of roadside tree, compensatory planting will comprise 714 no. of screen planting and road side planting result in a net gain of over 476 no. of trees.

·              The Proposed Improvement Works would result in negligible landscape impact and slight adverse visual impact assuming mitigation measures are incorporated.

·              Views towards the proposed improvement works are generally in short distance. For the potential local sensitive residents at Wing Ping Tsuen, it is assessed that advance boundary screen planting would screen the project from view. These local residents would therefore have no adverse visual impact caused by the proposed improvement works.

·              The landscape and visual impact assessment indicated that no significant impact would occur during construction and operation stage. The disturbance to existing road side tree would either be transplanting or compensated in the form of advance planting prior to the construction stage.  The disturbed traffic corridor and industrial/utility is man-made with low sensitivity to change, the landscape mitigation measure would minimize the adverse impact.  Adverse visual impact on the villages, which is in a local context, would be minimized with the incorporation of mitigation measures.  


Table 13.1       Summary of Residual Landscape Impacts (With Landscape Mitigation Measures)

 

LCU

With Recommend Mitigation Measure

Recommended Mitigation Measures

With Recommended Mitigation Measures

Landscape Impact during Construction Stage

Landscape Impact during Operation Stage

Threshold of Residual Landscape Impact during Construction Stage

Threshold of Residual Landscape Impact during Operation Stage

LCU1

Woodland and Shrub bed

Negligible

Negligible

NIL

Negligible

Negligible

LCU2

Transport corridor

Slight adverse

Slight adverse

LMM3, LMM4, LMM5, LMM6, LMM7,LMM8

Slight adverse

Negligible

LCU3

Institutional

Negligible

Negligible

NIL

Negligible

Negligible

LCU4

Residential

Negligible

Negligible

NIL

Negligible

Negligible

LCU5

Industrial/Utility

Slight adverse

Slight adverse

LMM1, LMM2, LMM4, LMM5, LMM7,LMM8

Slight adverse

Negligible

LCU6

Fishpond /Agricultural field

Negligible

Negligible

NIL

Negligible

Negligible

LE

 

 

 

 

 

 

LE1

Negligible

Negligible

NIL

Negligible

Negligible

LE2

Slight adverse

Slight adverse

LMM3, LMM4, LMM5, LMM6, LMM7, LMM8

Slight adverse

Negligible

LE3

Moderate adverse

Slight adverse

LMM1, LMM4, LMM5, LMM6

Slight adverse

Negligible

LE4

Negligible

Negligible

NIL

Negligible

Negligible

LE5

Slight adverse

Slight adverse

LMM1, LMM2, LMM4, LMM5

Slight adverse

Negligible

 

 

 

 


Table 13.2     Summary of Residual Visual Impact (With Landscape Mitigation Measures)

 

SVR Number

Without Recommendation Mitigation Measures

Recommended Mitigation Measures

With Recommendation Mitigation Measures

Visual Impact during Construction

Visual Impact during Operation

Significance Threshold of residual Visual Impact during Construction

Significance Threshold of residual Visual Impact during Operation

SVR1

 

 

 

 

 

VPT1.1

Moderate to Slight

Slight

LMM3, LMM4, LMM5, LMM6, LMM7, LMM8

Slight

Negligible

VPT1.2

Substantial to Moderate

 Moderate

LMM8

Moderate

Slight

VPT1.3

Moderate to Slight

Slight

LMM5, LMM7

Slight

Negligible

VPT1.4

Moderate to Slight

Slight

LMM2, LMM4, LMM5, LMM6, LMM7

Slight

Negligible

VPT1.5

Negligible

Negligible

NIL

Negligible

Negligible

SVR2

 

 

 

 

 

VPT2.1

Moderate to Slight

Slight

LMM2, LMM4, LMM5

Slight

Negligible

VPT2.2

Slight

Slight

LMM3, LMM5

Negligible

Negligible

VPT2.3

Moderate to Slight

Slight

LMM3, LMM4, LMM5, LMM6, LMM7

Slight

Negligible

VPT2.4

Negligible

Negligible

NIL

Negligible

Negligible

SVR3

 

 

 

 

 

VPT3.1

Substantial to Moderate

Moderate

LMM3, LMM4, LMM5, LMM6, LMM7, LMM8

Moderate

Slight

VPT3.2

Substantial to Moderate

Moderate

LMM1, LMM2, LMM3, LMM4, LMM5, LMM6,LMM7,LMM8

Moderate

Slight

VPT3.3

Negligible

Negligible

NIL

Negligible

Negligible

VPT4

Negligible

Negligible

NIL

Negligible

Negligible

VPT5.1

Substantial to Moderate

Moderate

LMM3, LMM4, LMM5, LMM6

Moderate

Slight

VPT5.2

Negligible

 Negligible

NIL

Negligible

Negligible

 

 

13.24      It is predicted that the proposed improvement works would have limited landscape and visual impact.  With the Landscape Mitigation Measures, i.e. advance tree transplanting, advance boundary planting and advance screen planting along side the perimeter of the improvement works, conservation of existing soil and reuse in the planting area; the selection of fast growing native plant material below and adjacent to viaduct and noise barrier, the significance threshold of residual landscape impact would effectively be reduced from “slight adverse” in the construction stage to “negligible” in the operation stage.  In conclusion, the landscape and visual impact are considered “acceptable with mitigation measures”.

 

Land Contamination

 

13.25      Based on the information obtained from the site history, site reconnaissances and the information provided by FSD and LandsD, it is considered that some of the areas in the Study Area (Site A and Site E) appear to be potentially contaminated.  Based on the available information, the potential of land contamination impact at the Study Area is considered surmountable. 

 

13.26      It is proposed that land contamination assessment works should be conducted at the two proposed potential zones for conducting site contamination investigation (S-a and S-e) prior to the commencement of site clearance / construction works.  During the construction works of the Project, the recommended mitigation measures should be implemented, in order to minimize the potential health impact on the construction workers.

 

Overall Conclusion

 

13.27      The findings of this EIA have provided information on the nature and extent of environmental impacts arising from the construction and operation of the Designated Project element of the Improvements to San Tin Interchange project.  The EIA has, where appropriate, identified mitigation measures to ensure compliance with environmental legislation and standards.

 

13.28      Overall, the EIA Report for the Improvements to San Tin Interchange has predicted that the Project would comply with all environmental standards and legislation with the implementation of the proposed mitigation measures for construction and operation phases.  This EIA has also demonstrated the acceptability of the residual impacts from the Project and the protection of the identified environmentally sensitive resources.  Environmental monitoring and audit mechanisms have been recommended before and during construction, where necessary, to verify the accuracy of the EIA predictions and the effectiveness of recommended mitigation measures.