6                     Ecology

6.1               Introduction

6.1.1          According to the EIA report, the ecological impacts that could arise from the Project are considered to be minor, provided that the recommended mitigation measures are correctly implemented. Specific ecological monitoring programme is not considered necessary but environmental audit is required to ensure ecological impacts form the construction and operation of the Project is kept within acceptable level, and the application and mitigation measures are practical and effective.

6.1.2          The EIA report concluded that the possible impacts from the Project were mainly associated with impacts on Little Egret during construction phase, permanent removal of roadside plantation and mortality of bird due to collision with the proposed permanent noise barrier.

6.2               Mitigation of Adverse Ecological Impacts

6.2.1          Following EIAO-TM Annex 16 guidelines, mitigation measures are discussed in this section to avoid, minimise and compensate for identified ecological impacts.

Avoid

6.2.2          Construction activities should be confined to developed areas of low ecological value. There should be no direct impact on other habitats within the Study Area.

Minimise

6.2.3          Noise mitigation measures, including installation of noise-emitting construction plant away from egretry, careful scheduling of noisy works with high disturbance impact to avoid breeding season of ardeid species (i.e. mid March to August) to prevent impacts on nesting activities of Little Egret, operation of well-maintained machinery, and use of noise reduction facilities could be implemented to mitigate noise impacts arised from construction activities such as road widening and road paving.   Temporary noise barrier should also be used to reduce the level of noise during construction. Noise impact would be minimised during operation phase as permanent noise barrier has been proposed to be constructed. These measures could minimise disturbance to habitats within and adjacent to the proposed Works Area.

6.2.4          In order to minimise the impact of construction dust to the vegetation and associated wildlife within and around the proposed Works Area, practical measures such as regular watering, complete coverage of dusty material storage piles, and the use of minimum practical height for dropping excavated material should be implemented.

6.2.5          Standard good site practice measures should be implemented and should include:

§         Placement of equipment in designated Works Areas within the existing disturbed land.

§         Construction activities should be restricted to the proposed Works Area.

§         The proposed Works Area should be reinstated immediately after completion of the works.

§         Open burning on proposed works site is illegal, and will be strictly enforced.

§         Waste skips should be provided to collect general refuse and construction wastes, which should be disposed regularly and properly off-site.

§         Soil contaminated by fuel leaked from construction plants should be removed and treated.

6.2.6          Mitigation measures should be implemented to prevent and minimise the indirect impacts to the nearby Tuen Mun River Channel by controlling construction site runoff and drainage from the proposed Works Area. Site runoff could be directed towards regularly cleaned and maintained sand traps, silt traps and where appropriate, oil/grease separators to minimise risk of sedimentation and pollution to the river channel. Debris and rubbish generated on-site should be collected, handled and disposed properly.

6.2.7          In order to prevent and minimise the chance of bird collision during operation phase, falcon sticker, tinted materials, embedded opaque stripes and superimposed patterns of thin opaque stripes are methods that could be used during the design of noise barrier.

Compensate

6.2.8          Compensatory planting is recommended as the current roadside plantation must be removed to give way to the works. Species of choice should be composed of similar native species and the felling and planting ratio should be no less than 1:1 in terms of quality and quantity.