15. Summary of Environmental Outcomes

15.1 Population and Environmental Sensitive Areas Protected

The EIA process has facilitated integration of environmental considerations into the design process for the Project. The principal measures identified are those achieved through careful routing of the gas mains and locating of the pigging stations and the installation methodology or gas mains design. Moreover, a number of mitigation measures have been identified to minimise the potential for adverse environmental impacts to occur. The mitigation measures are detailed in full in the Environmental Mitigation Implementation Schedule in Section 14. These measures will be implemented by Towngas and, if appropriate, enforced by EPD by means of the EIAO.

One of the key environmental outcomes has been the ability to plan, design and ultimately construct the Project so that direct impacts to sensitive receivers are avoided, as far as practically possible. A detailed assessment of alternatives for routing the gas mains and locating the pigging stations was undertaken. A number of alternative gas mains routes were studied and the preferred alignment minimises impact on water quality and sediment management and avoids direct impacts to ecologically sensitive habitats and species such as corals and marine archaeology. A number of alternative pigging stations locations were studied and the preferred locations for pigging stations avoids encroach the Man Hong Street playground/open space area and proposed “Open Space”, avoids interface with the existing petrol/LPG filling stations and a waterfront promenade will be available next to the To Kwa Wan (TKW) pigging station for use by the general public which avoids direct impact on recreational uses serving the public and local residents.

15.2 Environmental Friendly Designs Recommended and Problems Avoided

In preparing the design and installation method for the gas mains, a key concern was to take steps so that indirect impacts to water quality sensitive receivers, through disturbance to the seabed, were avoided or minimised. Consequently, the following approaches were taken to achieve the above.

¡ Reduction in Indirect Impacts - The alignment chosen for the submarine gas pipelines was located at a sufficient distance from ecological sensitive receivers so that the temporary dispersion of sediment from the installation works was not predicted to affect the receivers at levels of concern (as defined by the WQO and tolerance criteria).

¡ Installation Equipment - The use of grab dredging, “bottom-pull” and “float and sink” along the entire route has minimized the severity of perturbations to water quality and hence allowed compliance with the WQOs at the sensitive receivers. This careful selection of installation equipment has helped avoid impacts to sensitive ecological receivers.

¡ Adoption of Acceptable Working Rates - The modelling work has demonstrated that the selected working rates for the dredging, “bottom-pull” and “float and sink” works will not cause unacceptable impacts to water quality. Consequently, unacceptable indirect impacts to marine ecological resources have been avoided.

In preparing the design of the pigging stations, a key concern is to take steps so that air quality, noise, waste management and landscape and visual impacts were minimised. Consequently, a boundary wall will be constructed to screen the above-ground pipeworks of TKW pigging station to minimise air quality and noise impact and a planting strip will be reserved in front of the boundary wall of the TKW pigging station to soften its’ visual appearance and thus minimises visual impact. A planting strip together with a visual barrier inside the existing fence on the east boundary along Hoi Yu Street of NP pigging station will be constructed to soften its’ visual appearance and thus minimises visual impact. Landscape impact assessment for the two pigging stations are incorporated in the approved planning permission applications under Section 16 of the Town Planning Ordinance.

15.3 Environmental Benefits of the Project

The primary objective of this Project is to construct a new gas pipeline network from To Kwa Wan to North Point so as to replace the existing one affected by the proposed Cruise Terminal dredging works adjacent to the existing Kai Tak runway and the proposed Central Kowloon Route crossing the Kowloon Bay at Ma Tau Kok as they were requested to be diverted.

The new gas pipeline network would ensure the existing gas facilities from To Kwa Wan to North Point are replaced before the decommissioning of the existing facilities. With the proposed new gas pipeline network, the risk of no gas supply after the decommissioning of the existing facilities would be minimised. It would also minimise the requirement of constructing new gas production and distribution facilities in the highly congested urban areas with heavy traffic and congested underground utilities, and hence prevents associated environmental impacts arisen from those works.