1 EXECUTIVE SUMMARY

1 EXECUTIVE SUMMARY

This desktop review has provided an assessment of the environmental and risk constraints associated with the development of a gas pipeline between the Cheng Tou Jiao Liquefied Natural Gas Receiving Terminal (GT) on the Mainland and the Towngas Gas Production Plant (GPP) within the Tai Po Industrial Estate in the Hong Kong SAR.

A constraints review was undertaken, as presented in Section 2, which assessed three potential corridors (Figure 1.1a) in which the pipeline could be located. These included:

* a land based route (Option 1);

* a combination land and marine based route (Option 2); and,

* a marine based route (Option 3).

Within each of these corridors, the physical and environmental constraints to the system were identified and four possible routes were identified for further review and assessment.

Sections 3 and 4 examine their potential impacts to the environment and potential risks to the public, respectively. The environmental impacts associated with each option were classified into five categories. Based on this analysis, it was determined that the preferred route was the marine option with a landing point on Tap Mun, ie Option 3a.

The land based route, Option 1, and the combination land based option and marine route, Option 2, were less preferred due to their "High" potential for ecological and landscape/visual impacts. Both options have the potential for impacts to sensitive ecological resources within the vicinity of Starling Inlet, Country Parks (Plover Cove and Pat Sin Leng) and along the Ting Kok Road. Option 3b, the marine option with a landing point on Wong Chuk Kok Tsui was considered to be similar to Option 3a, landing at Tap Mun. However, Option 3b would land within the boundaries of a Country Park and a designated SSSI which hold conservation status. Option 3a was considered to be the preferred route in terms of the environmental aspects.

With regard to the potential risks of each option, the most direct routes into Hong Kong waters from the Cheng Tou Jiao GT were preferred, ie the marine routes Options 3a and 3b. The land and combination land and marine based routes, Options 1 and 2, would pose more risk to the public due to their greater exposure to the population and the greater length of pipeline that would be required. Options 3a and 3b were considered to be similar in terms of their risk potential.

Thus, considering both the potential environmental impacts and the potential risks associated with the project, Option 3a, was preferred and was taken forward for more detailed analysis.

1.1 STRUCTURE OF THIS ANNEX

The structure of this Annex is as follows:

* Section 2 describes the route selection criteria and identifies the routes that have been selected for review.

* Section 3 provides a review of the potential environmental impacts associated with the route options.

* Section 4 provides a review of the potential risks associated with the route options.

2 ROUTE SELECTION

This Section describes the criteria that have been used for establishing the routing of the submarine pipelines. Although the routing corridors have been broadly defined, the environmental and physical constraints within, and in proximity to, the corridors have been reviewed to further define the pipeline routes.

2.1 ROUTE SELECTION CRITERIA

During the route selection within the three corridors, environmental, physical and risk constraints were reviewed to determine the most appropriate pipeline corridor and landing areas which avoided, as far as possible, potential areas of impact.

2.1.1 Environmental Constraints

The areas of known environmental importance that have been identified during the route selection process have been avoided as far as practicable. Each constraint is illustrated on Figure 2.1a and is explained in Table 2.1a.

Table 2.1a Environmental Constraints

Constraints	Notes
Land Based Constraints
· sites of special scientific interest (SSSIs)	There are several SSSIs located within the Study Area which have been designated for a variety of reasons. Some of the SSSIs support important bird colonies, eg No 1 at Yim Tso Ha Egretry in Starling Inlet, whereas others have been designated for geological reasons, eg No 38 Tolo Channel (Northern Coast).
· designated country parks	There are seven Country Parks in the Study Area, six of which abut the coastline. Country Parks are gazetted for conservation, recreation and educational purposes and are under the control of the Country and Marine Parks Authority (CMPA).
· coastal protection/land conservation areas/green belt	The Planning Department has designated several areas as Coastal Protection Areas (CPA) and Conservation Areas (CA) on the Outline Zoning Plans for specific locations within the Study Area.
· land sites of cultural heritage (declared monuments)	There are declared monuments located throughout the Study Area. Any disturbance to these monuments should be avoided and consultation should be initiated if necessary with the Antiquities & Monuments Office of the Leisure & Cultural Services Department.
Marine Based Constraints
· marine park	There are three Marine Parks in the Study Area at Yan Chau Tong, Hoi Ha Wan and Ping Chau. Marine Parks are gazetted for conservation, recreation and educational purposes and are under the control of the Country and Marine Parks Authority (CMPA).
· fish culture zones	There are 13 Fish Culture Zones within the Study Area, the majority of which are located within enclosed bays. Impacts to FCZs are controlled by the Water Pollution Control Ordinance and the Marine Fish Culture Ordinance. Developments within 500m of an FCZ are subject to claims for ex gratia allowances. FCZs can be regarded as water quality sensitive receivers and impacts to them should be avoided as far as possible.
· sites of special scientific interest (SSSIs)	There are several SSSIs located within the Study Area which have been designated for a variety of reasons, eg the SSSIs at Ting Kok and Kei Ling Ha were established because of their large mangrove stands, whereas Sham Chung was established because of the large number of fossils present there.
· proposed and gazetted artificial reefs	Artificial reefs (ARs) have been deployed in the Yan Chau Tong and Hoi Ha Wan Marine Parks and are proposed for deployment within Long Harbour. ARs are deployed to enhance fisheries and marine ecological resources and are under the jurisdiction of AFCD. ARs can be regarded as water quality sensitive receivers and impacts to them should be avoided as far as possible.
· fisheries protection areas (proposed)	A fisheries protection area is proposed or designation under the Fisheries Protection Ordinance within Tolo Harbour, Channel and Long Harbour. Although designated to provide specific controls on fishing activities the area can be regarded as a sensitive water body and any impacts should be minimised as far as possible during construction to achieve compliance with the water quality objectives.
· Corals	Corals are located throughout the area as detailed in Annex C – Section 2.2. Direct impacts should be avoided as far as possible.

2.1.2 Physical Constraints

The physical constraints that were considered during the route selection included those shown on Figure 2.1b and discussed in Table 2.1b.

Table 2.1b Physical Constraints

Constraints	Notes
Land
· areas of steep topography/hillslopes	Avoidance of such geographical features is recommended in order to minimise the amount of slope cutting required and to minimise the risks of boulder falls or landslides damaging the pipelines.
· areas of restricted access	There is one within the Study Area which has restricted access, the Closed Area Boundary at Sha Tau Kok. Passing the pipeline through such an area requires permission from the Commissioner for Police, Transport, Immigration and Customs and Excise Dept.
· areas requiring multiple bends/curves	From a safety perspective planning a pipeline with a minimum number of bends is preferable as it minimise the number of potential failure points.
· areas close to present or planned utilities that may require maintenance.	Utilities are present on land which may have to be avoided during the route planning. These include water pipes, electricity cables and gas pipelines.
· Reservoir	The Plover Cove Reservoir is considered to be a constraint to the pipeline and Water Supplies Department (WSD) are the lead authority for the reservoir.
Marine
· designated areas of marine dredging and mud disposal	Although there are no active dredging areas within the Study Area there is an old marine disposal round located in Mirs Bay which should be avoided to minimise disturbance to the disposed dredged muds.
· seawater intake points	Seawater intake points are located at the Marine Science Laboratory at Tai Po, the Shatin seafront and the WSD flushing water intake at Tai Po Industrial Estate. Intakes have their own water quality standards that have to be met during construction.
· existing and proposed anchorage	A proposed Dangerous Goods Anchorage (DGA) is located at the mouth of Tolo Channel in Mirs Bay. The DGA should be avoided due to the potential for damage to the pipelines. If the DGA cannot be avoided then pipeline protection measures will be required.
· heavily trafficked marine vessel fairways	The Yantian approach is a busy fairway for container vessels travelling to the Yantian. Port. Vessel traffic is expected to increase in the future and consequently laying at pipeline in the fairway would be hazardous from an operational and maintenance perspective. If the fairway cannot be avoided then pipeline protection measures will be required.
· areas of current, future or proposed reclamation	Within Tolo Harbour an area is currently being reclaimed at Pak Shek Kok. This area should be avoided.
· typhoon shelters	The Yim Tin Tsai typhoon shelter should be avoided because high marine traffic is expected.
· utilities (cables, pipelines and outfalls)	Utilities may have to be avoided during the route planning. These include water pipes, electricity cables and gas pipelines. Where crossings are necessary these are preferably conducted at right angles to minimise the chances of disturbance to the existing utility.

In addition, general risk constraints were also identified along the route corridors to reduce the potential risk to the public during the operation of the pipelines. The potential risk constraints that were considered during the route corridor selection process include the following:

* the general avoidance of populated areas;

* the avoidance of areas that were considered to have a high degree of risk associated with their activities (e.g. anchorage areas, major fairways; and

* the selection of the most direct route between the two sites, to reduce the length of pipeline required.

A summary map illustrating all of the environmental and physical constraints is presented in Figure 2.1c. The map also illustrates the three options highlighted for examination following the review of potential constraints.

2.2 ROUTES SELECTED FOR REVIEW

2.2.1 Land Route (Option 1)

The land based route, within the HKSAR, is shown in Figure 2.1c. Within the Mainland, the pipelines would be routed approximately 0.5 km to 2 km north from the coastal highway from Cheng Tou Jiao to Yantian, to avoid populated areas. The pipelines would utilise the Sha Tau Kok border crossing and, within the HKSAR, the route would follow Sha Tau Kok Road to Luk Keng Road, bordering the western edge of Starling Inlet (Sha Tau Kok Hoi). The route would then follow Bride's Pool Road located within the Pat Sin Leng Country Park to Tai Mei Tuk, then follow Ting Kok Road to the Tai Po Industrial Estate. The land route would utilise the existing road system, as much as possible. In areas where the road is narrow, land take may be required on either side and this could result in the loss of ecological habitats or the cutting of slopes. The total length of the pipeline would be approximately 92 km.

2.2.2 Land/Marine Route (Option 2)

The land/marine based route, within the HKSAR, is shown on Figure 2.1c. The land/marine route would traverse the northern portion of Mirs Bay from the Cheng Tou Jiao GT, north of Kat O Chau to the edge of Starling Inlet (Sha Tau Kok Hoi) and land within the proximity of Yim Liu Ha. The route would then follow the same road system as described above for Option 1. The total length of the pipeline within the HKSAR would be approximately 41 km.

2.2.3 Marine Route (Option 3)

The marine based route, within the HKSAR, is shown on Figure 2.1c. For the marine route, two possible alignments were reviewed, and are referenced as Option 3a and Option 3b. Option 3a would traverse east from the Cheng Tou Jiao GT and travel south of the proposed Dangerous Good Anchorage site to a landing point on the northern most portion of Tap Mun. The pipelines would then travel through the Tolo Channel to the GPP at Tai Po Industrial Estate. The total length of the pipeline within the HKSAR would be approximately 32 km. Option 3b would traverse east from Cheng Tou Jiao GT and travel north of the Dangerous Good Anchorage with a landing at Wong Chuk Kok Tsui then follow the same route as Option 3a to the GPP. The total length of the pipeline within the HKSAR would be approximately 32 km.

The options as identified above are further reviewed in terms of their potential for environmental and risk impacts in Sections 3 and 4.

3 ENVIRONMENTAL REVIEW OF ROUTE OPTIONS

This Section provides a preliminary review of the environmental impacts associated with each identified option. For the purpose of this review and to allow for a comparison between the options, the potential impacts have been classified into the following categories of severity, as defined below:

* low potential for adverse impacts and represents impacts that are not considered to be unacceptable without mitigation.

* low/moderate potential for adverse impacts which can be mitigated through good working practices without residual impacts.

* moderate potential for adverse impacts which are slightly greater than low/moderate impacts and can likely be mitigated through the application of standard measures and working practices.

* moderate/high potential for adverse impacts which, although resulting in a greater impact than those of moderate potential, could still be mitigated through the development and application of mitigation measures.

* high potential for adverse impacts which would require extensive mitigation measures to reduce impacts to an acceptable level and may result in residual impacts, even with the implementation of mitigation measures.

A description of the potential impacts associated with each option has been provided in the following sections and classified in accordance with the above categories.

3.1 LAND USE CONSTRAINTS

3.1.1 Option 1 - Land Route

For Option 1, the gas pipelines would pass through the following districts and townships within the mainland: Kuichong Town, Xichong, Meisha, Yantian Districts and Shatoujiao Town. For each of these areas, permission would need to be granted and the appropriate permits would need to be obtained from governing authorities prior to commencement of the project. Further, an Environmental Impact Assessment (EIA) would need to be conducted and an Environmental Permit (EP) would need to be obtained from the Shenzhen Environmental Protection Bureau.

Within the HKSAR, the project would be subject to the Environmental Impact Assessment Ordinance (EIAO), and an EP would be required prior to construction of the Project. Further, for the portion of the pipeline installed within the Closed Area Boundary (CAB), approval would be required from the Security Branch, Customs and Exercise Department, Immigration Department, Transport Department, HKSAR Police Force and other relevant government departments concerned with this area.

For the segment of the pipeline that traverses from Sha Tau Kok to the Tai Po Industrial Estate, the project would pass through areas designated by the Town Planning Board (TPB) as "Conservation Area" (CA), "Coastal Protection Area" (CPA), "Site of Special Scientific Interest" (SSSI) and "Country Park" (CP), shown on Figure 3.1a. The land use planning designations have been assigned to these areas for multiple purposes, amongst which include retaining their existing natural character of and for providing a high degree of protection based on their conservation value.

Prior to development within these areas, permission for the routing of the pipelines and installation of a PIG station and flare would need to be obtained in advance from the Country and Marine Parks Authority (CMPA), under the Country Parks Ordinance, and from the TPB under the Town Planning Ordinance.

3.1.2 Option 2 - Marine/Land Route

Option 2 would avoid passing through multiple provinces in the Mainland; however, an EIA would need to be conducted and an EP would need to be obtained from the Shenzhen Environmental Protection Bureau for the marine based segment of the pipelines, prior to construction within Mainland waters.

Within the HKSAR, the project would be subject to the EIAO, and an EP would be required prior to construction within the HKSAR waters. Further, the project would be subject to the Foreshore and Seabed (Reclamations) Ordinance (Cap 127) (FSRO) and would require approval from the Director of Lands for the gazettal of the affected area of the seabed in which the pipelines are to be installed.

For the land based portion of the project, similar approvals would be required those specified above for Option 1.

3.1.3 Option 3 - Marine Route

Similar approvals would be required for both Option 3a (Tap Mun) and Option 3b (Wong Chuk Kok Tsui), as described for the marine based segment of Option 2.

Option 3a, landing at Tap Mun, represents one of the few stretches of land in the vicinity of the pipeline routes that is not designated as a Country Park. The island of Tap Mun is currently not covered by any of the Planning Department's Outline Zoning Plans (OZP). The only plan that covers the area is SRNE-ST97/1 (May 1997) which is an administrative/indicative plan attached to the Northeast New Territories planning statement. Any proposed development on Tap Mun would have to be authorised by the District Lands Office (DLO) of Tai Po (Lands Department).

For Option 3b, additional approval would be required from the CMPA for the landing site and proposed PIG station and flare at Wong Chuk Kok Tsui, situated within the Plover Cove Country Park and Tolo Channel (Northern Coast) SSSI.

3.2 WATER QUALITY IMPACTS

3.2.1 Option 1 - Land Route

For the land based option, it is expected that extensive slope cutting will be required within the rural areas of the Mainland portion of the pipeline system and, potentially, for the segment of the pipeline along Bride's Pool Road. Water quality impacts may occur during construction works as a result of runoff and drainage containing increased loads of suspended solids and other contaminants (such as oil and chemical waste from heavy machinery and cement derived materials used for road pavement). The runoff may result in physical effects including the blockage of drainage channels, increased suspended solids concentrations in receiving waters and accretion of suspended solids with high pH from cement derived materials. Potential biological effects may also occur from these activities which may affect aquatic life within the receiving water courses.

It is expected that with good site management, runoff can be controlled from entering the surrounding waters and potential adverse impacts can be avoided. The types of measures that may be required to reduce the impacts include: containment of stockpiled materials, proper collection of spent cement mix or other paving materials, undertaking extensive slope cutting work outside the wet season as well as other measures to prevent runoff from occurring. Based on the above, water quality impacts are considered to be of moderate potential and can be mitigated through the application of standard practices.

3.2.2 Option 2 - Marine/Land Route

For the marine based aspects of Option 2, the proposed route for the submarine pipelines would pass through the designated Water Control Zone (WCZ) of Mirs Bay. In accordance with the Water Pollution Control Ordinance (WPCO), the project would be required to comply with the Water Quality Objectives for this area and all discharges during the project implementation and operation phases would be required to comply with the Technical Memorandum for Effluents Discharged into Drainage and Sewerage Systems, Inland and Coastal Waters (TM) issued under Section 21 of the WPCO, which defines acceptable discharge limits for different receiving waters.

Mirs Bay is situated in an area of open sea, which is exposed to oceanic waters to the south. The tidal currents along the route are fairly low, with maximum speeds on large spring tides of approximately 0.25 ms-1. The water quality data from EPD monitoring stations, 1997, show compliance with the WQOs. The sediment quality within this area is expected to be better than other areas of eastern waters, such as Tolo Harbour; however, contamination levels within sediments to be dredged would be required to be determined as part of the Environment, Transport and Works Bureau Technical Circular No 34/2002 Management of Dredged/Excavated Sediment (ETWBTC 34/2002).

For those areas in which the pipelines are to be laid into a pre-dredged trench, during the dredging process, a quantity of the sediment removed from the sea bed would be lost to suspension and would be dispersed through tidal currents, forming sediment plumes. For the section of the pipeline that would be installed by jetting, a fluidised mixture of water and sediment would be formed close to the sea bed which would also be transported by tidal currents. Although, the suspended sediments for both options are expected to settle rapidly, impacts could occur to nearby sensitive ecological receivers as a result of elevated suspended solids.

The water quality sensitive receivers identified along the proposed pipeline route include: water intakes, fish culture zones and areas of ecological value. The pipeline corridor has been defined to avoid these areas as much as possible and most of the identified sensitive receivers are situated over 200m from the pipelines.

As such, it is expected that the potential impacts to water quality could be controlled through measures such as restricting equipment requirements (requiring the use of watertight grabs, bottom sealed barges, etc) and through programme modification (controlling the dredging rate). The need for such measures would be determined by detailed computer modelling of sediment plume dispersion and water quality. Impacts are expected to be of moderate/high potential. However, it is believed that with the implementation of the necessary mitigation measures, impacts to water quality can be controlled to within acceptable levels.

3.2.3 Option 3 - Marine Route

The proposed routes for the submarine pipelines would pass through the Tolo Harbour and Channel WCZ and the Mirs Bay WCZ. The Tolo Harbour is relatively confined and has tidal currents that are generally low <0.1 ms-1. As a result of the low current speeds, the flushing rate is low and residence times for the waters are long. The water quality in Tolo Harbour often exceeds the WQO for dissolved oxygen and is often subject to high rates of algal growth.

The water quality sensitive receivers identified along the proposed pipeline route include: water intakes at the Tai Po Industrial Estate, fish culture zones (Lo Fu Wat, Yim Tin Tsai, Yim Tin Tsai East and Yung Shue Au) and other areas of ecological value (including the SSSIs along the route, Hoi Ha Wan Marine Park, numerous subtidal habitats and fisheries spawning and nursery areas) . The pipeline corridor has been defined to avoid these areas as far as possible given the physical constraints of the area.

Due to the low current speeds within Tolo Harbour, suspended solids formed during jetting will tend to settle out rapidly. However, due to the low flushing rates, the waters within Tolo Harbour are expected to be more susceptible to pollution. In general, Option 3a and 3b are expected to have similar impacts as those described above for Option 2 and it is expected that similar measures as those described for Option 2 could be adopted to control water quality impacts to an acceptable levels. Impacts are therefore classified as moderate/high potential.

3.3 ECOLOGICAL IMPACT

3.3.1 Option 1 - Land Route

For the Mainland route of Option 1 (between Cheng Tou Jiao and Sha Tau Kok) the pipelines are expected to be situated outside population centres, in rural areas, approximately 0.5 to 2 km north of the Coastal Highway. The expected ecological receivers in this area include habitats supporting flora and fauna where the pipelines will be installed.

Within the HKSAR boundary, the ecological sensitive receivers along the segment of the project between Sha Tau Kok Road and Luk Keng Road, include:

* mangroves of high landscape and ecological value (near Muk Min Tau and Wu Shek Kok);

* Yim Tso Ha Egretry SSSI (a nesting site for the Chinese Pond Heron, Little Egret, Cattle Egret, the rare Swinhoe's Egret and Night Herons);

* A Chau Island SSSI (a nesting area for migratory birds);

* Luk Keng Marsh;

* large fishponds (at the junction Sha Tau Kok Road and Luk Keng Road, Hoi Pui Leng, Nam Chung Yeung Uk); and

* the general marine ecology of Sha Tau Kok Hoi (Starling Inlet).

The ecological sensitive receivers are adjacent to and, in some areas, are surrounding Luk Keng Road (see Figure 3.3a). The ecological sensitive receivers along Bride's Pool Road include the natural vegetation within the Pat Sin Leng and Plover Cove Country Parks, the Pat Sin Range (forested ravine of high botanical value) and Chiu Keng Tam (Woodland) "Special Areas" and numerous stream courses segmenting the roadway. The ecological sensitive receivers along Ting Kok Road include the Ting Kok SSSI (mangrove community) and Shuen Wan Egretry SSSI (fung shui woodland and an egret nesting area).

The habitats along the proposed route comprise of those considered to be of high ecological value (see Figure 3.3b). The habitats include mangrove, intertidal mudflat, wetland and fishpond areas.

A significant amount of land may be disturbed during the installation of the pipelines and PIG station, particularly for areas requiring slope cutting and in areas where the pipelines cannot be placed below existing paved areas. Land would also be required along the pipeline corridor (3m either side) to act as a reserve for maintenance access and a buffer area would be required around the PIG station and flare to be located in the area.

As several of the ecological sensitive receivers are situated directly adjacent to the roads, it is expected that direct impacts would occur to some of these during construction. Due to the importance of this area for local flora and fauna, protection measures would be required as well as extensive mitigation measures for any areas directly affected. Although the extent of potential impacts would need to be addressed through further study, should an alignment be proposed, it is considered that, due to the sensitivity of the area, and the potential for direct and indirect ecological impacts to this area, the sensitivity for impacts is classified as high potential.

3.3.2 Option 2 - Marine/Land Route

The marine ecological sensitive receivers within this corridor include:

* numerous subtidal habitats of Kat O, Ngo Mei Chau and Wong Wan Chau as well as the eastern waters, in general which are regarded as supporting a high abundance and diversity of corals;

* fish culture zones (FCZ) situated at Sha Tau Kok, Ap Chau, Kat O and O Pui Tong;

* fishery spawning and nursery areas; and

* designated marine parks at Yan Chau Tong and Ping Chau.

The ecological sensitive receivers along the land based portion of the route are the same as those identified for Option 1 - Hong Kong Section.

The marine sensitive receivers for this option have been avoided during the route selection process; therefore, direct disturbance to these areas would not occur. However, during the installation of the gas pipeline, short term elevations in suspended solids concentrations would occur as a result of dredging/jetting operations associated with the pipeline deployment. The suspended sediment generated during dredging will cause an increase in turbidity in the water column and result in higher rates of deposition on the seabed. Such elevated suspended sediment levels may cause smothering of filter feeders such as corals and bivalves and clogging of gill filaments in fish and other organisms. Another potential impact would be the reduction in dissolved oxygen concentrations caused by elevated levels of suspended sediment.

The pipeline alignment would be located within close proximity of the Sha Tau Kok FCZ. The site is the fourth largest in Hong Kong, it has 105 licensed rafts (average) (AFCD 1998) and would require particular care during pipeline installation.

It is expected that water quality impacts can be controlled through standard measures (described above) which would also control impacts to ecological and fisheries resources. As marine impacts are expected to be mitigated through standard practices, the ecological impacts associated with this project have been classified as moderate/high potential. However, the sensitive receivers and impacts associated with the land based portion of this route would be the same as those identified for Option 1 and are considered to be of high potential.

3.3.3 Option 3 - Marine Route

The marine ecological sensitive receivers in the area include:

* numerous subtidal habitats in Tolo Channel and Mirs Bay including Tung Ping Chau, Chek Chau, Tap Mun, Ho Hai Wan, Wong Wan Chau, Kat O, To Tau Tsui, Pak Kok Chai and the eastern waters, in general, which have been reported as supporting a high abundance and diversity of corals;

* the Hoi Ha Wan, Yan Chau Tong and Ping Chau Marine Parks;

* Fish Culture Zones (FCZs) at Tap Mun, Kau Lau Wan, Sham Wan, Yung Shue Au, Ap Chau, Kat O, Yim Tin Tsai and Yim Tin Tsai (East), Lo Fu Wat;

* fisheries spawning and nursery areas; and

* Artificial Reef Deployment Areas Yan Chau Tong (Double Haven), Hoi Ha Wan and Long Harbour.

The sensitive areas of ecological value have been avoided, as far as possible, during the route selection process. However, indirect impacts to marine ecology may occur, as described for Option 2, due to impacts to water quality, in particular to the Lo Fu Wat FCZ and the Yim Tin Tsai FCZ in Tolo Harbour. Although sediment plume modelling would be required to more accurately predict potential impacts, it is expected that water quality impacts can be controlled through standard measures (see Option 2) which will in turn control impacts to ecology and fisheries resources. Therefore, impacts have been classified as moderate potential for the marine portion of this project.

For Option 3b, potential impacts may result from the development of a PIG station and flare at Wong Chek Kok Tsui, situated within the Plover Country Park and the Tolo Channel (Northern Coast) SSSI. It is expected that any development situated within these areas that would require disturbance to the natural coastline at the landing point and disturbance to the natural vegetation in the area which comprises baeckia shrubland and grassland which are classified as medium ecological value (see Figure 3.3c). Due to these potential impacts and also due to the conservation status of this site (SSSI), potential impacts are considered to be moderate/high potential.

For Option 3a, the landing point is situated outside the designated Country Park area. Habitats on Tap Mun, near the proposed landing site, comprise patches of mixed shrubland and lowland forest, which is considered to be of high ecological value (see Figure 3.3c). However, it is expected that the proposed PIG station could avoid these areas and on this basis, potential impacts are considered to be moderate potential.

3.4 LANDSCAPE/VISUAL IMPACTS

3.4.1 Option 1 - Land Based Route

The land based pipeline route from Cheng Tou Jiao to Sha Tau Kok, is expected to be located within rural areas which, due to the topography of the area, would require extensive slope cutting works for installation. Within the HKSAR section, the pipeline would traverse either near or within areas designated on the Luk Keng and Wo Hang Outline Zoning Plan (S/NE-LK/4) as "Conservation Area" (CA), "Coastal Protection Area" (CPA) and "Country Park" (CP). These areas are considered to be important in terms of their landscape value and visual amenity and are considered to be areas of high landscape and recreational value.

During installation of the pipelines, direct removal of vegetation is expected to be required which, due to the project requirements for a maintenance reserve area, could not be reinstated back to the original state. Furthermore, depending upon the area selected, tree felling and vegetation removal may be required for the development of a PIG station and flare. The station and flare would require a developed area of 6,000 m2 and a contiguous buffer area, which would be determined via the quantitative risk assessment undertaken for the project at a later stage.

The impacts associated with these works, particularly if undertaken within the Pat Sin Ling and Plover Cove Country Parks, are considered to be significant and have, therefore, been classified as having a high potential.

3.4.2 Option 2 - Marine/Land Route

There are no expected landscape and visual impacts associated with the marine works for the implementation of Option 2, aside from temporary views of pipeline laying and dredging/jetting works, which are not considered to be of significance. However, the land based construction works associated with Option 2 would be the same as those identified for Option 1 and are considered to be of high potential.

3.4.3 Option 3 - Marine Route

There are no expected landscape and visual impacts associated with the marine works for the implementation of Option 3. However, visual and landscape impacts may occur from the construction of the landing sites, PIG station and flare.

For Option 3a, the landing site and PIG station is expected to be located on the northern side of Tap Mun Island. Views of this site would be limited to those from the northern waters and are not expected to result in significant impacts. Minor vegetation removal is expected to be required for the installation of the station; however, it is expected that impacts would be minimal. The potential for landscape and visual impacts have, therefore, been classified as low/moderate potential.

For Option 3b, the pipelines would land within the Plover Cove Country Park and the Tolo Channel (Northern Coast) SSSI, which is considered to be important due to its unique coastal geological features and, as comprise areas of high landscape value. In order to develop within this area, prior approval would be required from the CMPA and TPB. Due to the sensitive nature of this site, disturbances to the coast and the development of a PIG station and flare in this location, the potential for impacts is considered to be classified as moderate potential.

3.5 WASTE

3.5.1 Option 1 - Land Route

Waste impacts would be limited to the construction phase of the project and are expected to be minimal. Most of the excavated material would be balanced on site with the possible exception of excess materials from slope cutting. Small amounts of construction and demolition waste would be produced from the projects, such as wood from form work broken asphalt, equipment and vehicle maintenance parts and unusable surplus concrete grouting mixes. Chemical wastes would also be produced in small quantities from equipment maintenance and small quantities of solid waste would be generated by construction workers. It is expected that these waste materials can be controlled by the contractor through standard waste management procedures during handling and disposal. Therefore, waste management impacts are classified as low/moderate potential.

3.5.2 Option 2 - Marine/Land Route

Waste materials likely to be generated by the proposed option include dredged marine sediment, minor quantities of chemical waste generated from machinery, and minor quantities of solid waste from the construction workers.

Marine sediments will be required to be dredged to provide protection to the pipelines within the Yantian Approach and potentially on the southern edge of the Yantian Fairway. The sediments in this area are not expected to be contaminated but would require verification as part of the sediment classification scheme under ETWBTC 34/2002; Management of Dredged/Excavated Sediment. Further, sediments would likely be required to be dredged at the Cheng Tou Jiao and Sha Tau Kok approaches. The disposal of these sediments would be undertaken in accordance with the ETWBTC.

The impacts associated with dredging marine sediments are addressed in the water quality and ecology sections of this review. Potential impacts are expected to be controlled through standard measures. Therefore, waste impacts associated with marine aspects of Option 2 are considered to be moderate potential.

The impacts associated with waste materials from land based construction works are the same as those described for Option 1 and are considered to be low/moderate potential.

3.5.3 Option 3 - Marine Based Route

The potential waste impacts associated with the marine based work described for Option 2 would be similar for Option 3a and 3b. However, it is expected that there would be a greater amount of sediment that would be required to be dredged and disposed. Further, sediments within areas of Tolo Harbour, particularly near the Tai Po Industrial Estate, are contaminated according to EPD's reports on Marine Water Quality in Hong Kong for 1991 to 2000. Such materials would require careful handing and disposal. The additional requirements for dredging potentially contaminated sediment are widely practised in the HKSAR and well-defined controls area available. Therefore, potential impacts are considered to be classified as moderate potential.

3.6 NOISE/AIR QUALITY IMPACTS

3.6.1 Option 1 - Land Route

The potential for noise and dust impacts would be limited to the construction phase of the project. Noise generated during operation of the PIG station would be infrequent (once every 10 years) and flaring would only be undertaken during emergencies. No noise would be generated during the routine operation of the pipelines.

Noise and dust would be generated during the excavation of the trenches for the pipeline as well as site clearance and construction of the PIG station and flare.

Sensitive receivers are located along the pipeline route include residential development areas along Sha Tau Kok Road (Ha Tam Shui Hang, Shan Tsui, Tsoi Yuen Kok, Nga Yiu Tau), rural village developments and residential developments along Ting Kok Road (Fortune Garden) and rural village developments along the alignment.

With the exception of the border crossing area around Sha Tou Kok, the background noise levels of areas along the route are generally low and will be limited to vehicles travelling along the local road system. Based on similar projects, noise generated from powered mechanical equipment required for the installation of the pipelines and associated facilities (including: hand held breakers, excavators, generators, lorries, compactors, etc.) are expected to range between 100 to 125 dB(A) at the source. It is expected that noise levels can be mitigated to within the EIAO-TM and Technical Memorandum for the Assessment of Noise from Places Other Than Domestic Premises, Public Places or Construction Sites (IND-TM) through the use of temporary barriers and careful equipment planning. Therefore, noise impacts are expected to be moderate potential.

The likely air quality impacts arising from the construction of the pipeline, PIG station and gas flaring facility are related to dust nuisance. It is expected that these nuisances can be controlled through measures stipulated in the Air Pollution Control (Construction Dust) Regulations employed in the worksite. Therefore, construction dust impacts are expected to be moderate potential.

3.6.2 Option 2 - Marine/Land Route

The noise sensitive receivers along the proposed marine route include rural villages on the outlying islands and residential developments within Ham Tam Shui Hang. The background noise levels in the area are considered to be generally low and are dominated by marine traffic near Yantian.

Noise impacts associated with jetting and dredging works are expected to range from 110 db(A) to 116 dB(A) at the source. Based on the expected equipment requirements, noise levels are expected to comply noise criteria as sensitive receivers would be situated more than 500 m from the proposed pipeline route. A detailed noise assessment would be required as part of the EIA process for this project to determine the potential extent of noise impacts. However, it is expected that noise levels can be controlled by standard measures and, therefore, noise impacts are classified as moderate potential.

Noise impacts are not expected to occur during the operation of the PIG station and flare due to the infrequent nature of their operation and are therefore classified as low potential.

Air quality impacts are not expected to arise from the marine based portion of the pipeline during installation and due to the infrequent nature of operations of the PIG station and flare, air quality impacts are considered to be low potential.

3.6.3 Option 3 - Marine Route

The potential for noise impacts would be similar to those identified for the marine based aspects of Option 2. As standard measures are expected to be able to control noise to an acceptable level under the EIAO TM, impacts are considered to be of moderate potential.

Air impacts are not expected to result from construction and operation of the project and are thus considered to be low potential.

3.7 CULTURAL HERITAGE

3.7.1 Option 1 - Land Route

Areas of potential constraint to the project include the archaeological site north of Nam Chung Lei Uk A, Sha Tau Kok old stone lime kilns at Tai Wan, burial grounds for indigenous villagers and the Kang Yung Shu Uk (declared monument). Protective measures would be required if the pipelines and associated developments were located in these areas. The potential for impacts to areas of cultural heritage are therefore considered to be of moderate potential for Option 1.

3.7.2 Option 2 - Marine/Land Route

There are no known marine archaeological remains located along the proposed route and, due to the historical disturbance to the seabed in this area (trawling, marine traffic, etc), no marine archaeological impacts are expected to occur. The land based portion of the route would have similar impacts to archaeological sites as described for Option 1 and the potential for impacts from this Option is considered to be of moderate potential.

3.7.3 Option 3 - Marine Based Route

For both Option 3a (Tap Mun) and Option 3b (Wong Chuk Kok Tsui), there are no known marine archaeological remains located along the proposed routes and, due to the historical disturbance to the seabed in this area (trawling, marine traffic, etc), no marine archaeological impacts are expected to be present. Further, there are no known areas of archaeological significance on the northern coast of Tap Mun or at the proposed PIG station location at Wong Chuk Kuk Tsui. Impacts to cultural and archaeological remains are therefore considered to be of low potential for Options 3a and 3b.

3.8 SUMMARY/RANKING OF POTENTIAL IMPACTS

The potential impacts associated with each Option are summarised in Table 3.1.

Table 3.1 Summary of Impacts

Issue Area	Option 1	Option 2	Option 3a	Option 3b
Water Quality	moderate	moderate/high	moderate/high	moderate/high
Ecology	high	high	moderate	moderate/high
Landscape/Visual	high	high	low/moderate	moderate
Waste	low	moderate	moderate	moderate
Noise/Air Quality	moderate	moderate	moderate/low	moderate/low
Cultural Heritage	moderate	moderate	low	low
Ranking

The land based route, Option 1, and the combination land and marine route, Option 2, are the least preferred. Both options have the potential for high ecological and landscape impacts within the vicinity of Starling Inlet, Country Parks (Plover Cove and Pat Sin Leng) and along the Ting Kok Road.

Option 3b, the marine option with a landing point on Wong Chuk Kok Tsui was considered to be similar to Option 3a, landing at Tap Mun. However, Option 3b would land within the boundaries of a Country Park and a designated SSSI. Due to the conservation status of the landing site for Option 3b and the potential landscape and visual impacts, Option 3a is preferred.

The preferred route is Option 3a from the perspective of environmental impacts.

4 RISK ASSESSMENT

4.1 RISK CONSTRAINTS

This Section provides a qualitative review of the potential risks associated with each option and identifies the preferred option which would result in the least amount of risk to the public.

4.1.1 Land Based Risk

As part of the pipeline system, a PIG station and flare are also proposed to be developed. A buffer area would be required around these components of the project and the potential risks associated with their operation are considered to be localised within the required buffer areas and would be required to meet the relevant standards. Therefore, the risks associated with this aspect of the project are considered to be common for each option.

For gas pipelines installed on land, there are two constraining requirements listed in the Hong Kong Planning Standards and Guidelines (HKPSG), Chapter 7, Section 3.3.4. These are:

* a restriction of development within 3m of high pressure pipelines; and

* a requirement to perform a Hazard Assessment for gas works to ensure that risks to the public are minimised.

Thus, a major constraint on the routing of the pipelines relate to the required compliance with the Hong Kong Risk Guidelines (HKRG).

Based on an analysis of the consequences of a pipeline release using standard correlations for release through an orifice, fireball and jet fire (1) (2), the expected maximum hazard distances associated with the pipelines are as follows:

* fireball 125m (diameter); and

* jet fire 107m (length).

If the pipelines were to pass within approximately 125 m of a development, it is expected that fatalities would result should any ignited release occur. Therefore, the pipelines should maintain a greater distance than 125 m from developments, as much as possible.

4.1.2 Marine Based Risks

There are no absolute constraints associated with a marine based route in terms of risk, with the exception of the following:

* the route should avoid passing through the Dangerous Goods Anchorage, and areas of high vessel traffic (Yantian Approach); and,

* the route must avoid the existing Towngas operated Naptha vessel

* mooring point within Tolo Harbour.

4.2 ROUTE OPTION SELECTION

The risk evaluation of the proposed route considered the following:

* how often the pipeline would be expected to fail; and

* what the consequences of the failure would be.

4.2.1 Frequency of Pipeline Failure

The frequency of failure of the marine sub-sea pipelines is related to marine traffic impact, whereas the frequency of failure of land based sub-surface pipelines are based on a uniform failure rate per unit length of line. These rates are shown in Table 4.2a.

Table 4.2a Failure Frequencies for Pipeline Sections

Area	Frequency of Failure
Subsea Pipeline
High Marine Traffic	5.2x10^-4 km^-1.year^-1
Moderate Marine Traffic	1.0x10^-4 km^-1.year^-1
Low Marine Traffic	4.4x10^-5 km^-1.year^-1
Underground Pipeline	1.1x10^-4 km^-1.year^-1
Flange Joint	1.59 x10^-3flange^-1.year^-1

The incidence of pipeline failure accounting for the length and direction of each route is shown on Figure 4.2a.

Figure 4.2a Frequency Analysis Results

As shown above, Option 1 (Land Based Route) is considered to be the least preferred option, with nearly double the failure frequency of the Option 3b (Marine Based Route - Wong Chuk Kok Tsui). This is due to the length of the pipelines (approximately 3 times longer than the sea routes) and the leak frequency assigned to underground pipelines, which is equivalent to a marine based sub-sea pipeline exposed to moderate sea traffic.

Option 3a (Marine Based Route - Tap Mun) was found to be similar to Option 3b but has slightly more risk associated with its implementation due to its crossing of the two shipping lanes, rather than one, the Yantian approach, and the Tolo Harbour Approach (see Figure 4.2a). Option 2 (Combination Land/Marine Route) was found to be only slightly better than Option 1, due to the length of underground pipeline, and the long distance of line adjacent to the Yantian Fairway.

4.2.2 Consequence of Pipeline Failure

The only parameter, which is important from the point of view of consequences of pipeline failure, is whether any population will be affected should the line fail.

A review of shipping traffic information confirms the assumption that there would be less population on the sea as compared with on the land (Table 4.2b). In terms of the location of the pipelines for Option 1, Land Based option, it has been assumed that the pipeline would traverse through primarily rural areas and avoid areas of high population.

Table 4.2b Population Density - Marine Vessels / Land

Type	Density	Length of Segment (km)
	(Population per m²)	Option 1	Option 2	Option 3a	Option 3b
Rural population	0.005	92	19	0	0
Urban population	0.01	0	0	0	0
Shipping population
High	1.2x10^-7	0	10	5	4
Moderate	1. 2x10^-8	0	8.5	8	9
Low	4x10^-9	0	4	19	18

It can be concluded, therefore, that Option 1 would be the worst, as it is exclusively land based, followed by Option 2. The difference in the potential consequences of pipeline failure between Option 3a and Option 3b is considered to be marginal.

4.2.3 Future Development/Sensitivity Analysis

With inspection and maintenance by Towngas, the pipelines should exceed their design life of 50 years. However, if increased development pressure occurs adjacent to the line, the risk associated with a land based option may increase due to:

* lack of care while carrying out construction adjacent to the line; and/or

* increasing numbers of people that would be exposed to the effects of a pipeline failure.

This type of increase in risk is not expected to occur for the sea routes, as the shipping figures used in the assessment were based on the expected growth of the Yantian Port.

4.3 CONCLUSIONS

Considering both the frequency and consequence of pipeline failure, it is concluded that Option 3a and Option 3b pose the least risk to the surrounding population during the operational life of the pipelines.

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(1) Chamberlain (July 1987) Developments in Design Methods for Predicting Thermal Radiation from Flares Chem Eng Res Des Volume 65

(2) CCPS (1994) Guidelines for Evaluating the Characteristics of Vapour Cloud Explosions, Flash Fires and BLEVEs