3 PROJECT DESCRIPTION

3.1 THE PROJECT

The works that are the subject of the EIA Study include the construction and operation phases of the Project. This section describes the key components of the Project.

The Project includes the following:

i. A Gas Receiver Station (GRS) at the Tai Po Gas Production Plant within the Tai Po Industrial Estate;

ii. A gas launcher facility at the LNG Receiving Terminal (GRT) at Cheng Tou Jiao, Shenzhen; and,

iii. Twin submarine gas pipelines connecting the GRS and the launcher facility.

The gas launcher facility at the GRT at Cheng Tou Jiao, Shenzhen (item ii above) is not included in this EIA Study, as it is not covered by the EIAO due to the planned location outside of Hong Kong.

The project site for the GRS is within the Tai Po Industrial Estate and will be located within the boundary of the existing Gas Production Plant run by Towngas.

The submarine pipelines will be laid through Tolo Harbour, Tolo Channel and Mirs Bay.

3.2 PROJECT DESIGN

The information presented in this section is taken from the preliminary design and will be subject to further study at the detailed engineering design stage.

3.2.1 Gas Receiver Station

The Gas Receiver Station (GRS) is located within the existing Towngas Gas Plant compound (Figure 3.2a). The main function is to provide pigging facilities for the offshore pipeline and a metering /pressure reduction terminal for the imported gas. The facilities in the GRS comprise the following:

Pig Receivers: The pipelines are designed to have a pig receiver located in the GRS suitable to accommodate intelligent pigging. An interlock system will be provided to ensure that the opening of pig trap during the pigging operation is undertaken in a strictly safe manner.

Metering and Pressure Reduction Facilities: The main facilities of the GRS are the metering and pressure reduction facilities. This comprises 3 main streams, each consisting of a redundant standby train to ensure continuity of supply. Typical design comprises active and monitor regulators and overpressure cut-off devices such as slam-shut valves. The design principle is that the failure of any two devices in an individual train should not create a hazard. Protection against inadvertent closure of slam-shut valves in other trains caused by a failure is provided by fitting stream discrimination devices. Filters are provided upstream of the metering and pressure reduction facilities to ensure the removal of any solids particles.

Safeguarding Facilities: Safeguarding facilities are strictly implemented to protect the GRS facilities and personnel against hazard conditions initiated by fires or explosions due to process malfunctions. The GRS is provided with Emergency Shut Down Valve (ESD), for isolating the GRS in case hazardous conditions arise. Control system related to ESD, and metering field instruments, etc., is centrally monitored in a dedicated and 24-hr manned control room.

Overpressure Protection: Overpressure protection by means of slam shut valves is provided to safeguard the pressure reduction station against the failure of the pressure control valves. The quick acting shut off of the gas supply has the advantage of not requiring flaring of large quantity of gas.

3.2.2 Pipelines

Onshore Section

The primary design code used for the onshore pipeline is IGE/TD/1 (1). Where IGE/TD/1 is silent, ASME B31.8 (2) is used as the complementary code. The recommended steel grade is API 5L for the 18" line pipe. The wall thickness verification for the onshore pipelines is performed on the basis of the internal pressure against functional load condition. The steel wall thickness for the land pipeline is designed in accordance with IGE/TD/1. The selected Maximum Operating Pressure (MOP) of the pipeline system is 90 barg. The design pressure for the pipeline system based on HIPPS (High Integrity Pressure Protection System) control system is 92 barg. The hydrotest pressure in IGE/TD/1 is 1.5 MOP (135 bar).

Coating Selection: The coating recommended for the buried onshore section is a three-layer PE coating that offers a combination of all the best properties of fusion bonded epoxy, including excellent adhesion and cathodic disbondment, and at the same time offers excellent mechanical protection. The selected nominal coating thickness is 2.9 mm. Heat shrink sleeves are used at field joints to provide a continuous protection. A paint coating system is utilized for the above ground pipeline and its field joints. A 250 ƒÝm dry film thickness (DFT) polyurethane system is recommended. These coating systems are based on the preliminary design and will be subject to further study.

Cathodic Protection System: The onshore pipeline is isolated from the offshore pipeline and GRS by monolithic insulation blocks at the landfall area and GRS site. The cathodic protection will be either an impressed current system or a sacrificial anode system with magnesium base anodes.

Bend Radius: All bends are to be designed with a minimum radius of 3D to allow for future intelligent pigging operation.

Submarine Section

The subsea section will consist of twin 18'' OD (450 mm outer diameter), API 5L Grade X60 pipeline(s) with a pipe wall thickness of 11.1 mm. The pipelines are designed as a bundle and will be installed in a common trench at a nominal separation of 857 mm centre to centre (c/c).

The pipelines will be coated externally with asphalt enamel coat and wrap and have an outer layer of steel reinforced concrete weight coating. The concrete coating is intended to provide lateral stability and will be about 38 to 52 mm thick. Cathodic protection for the submarine section will be provided by aluminium based sacrificial anodes.

The gas transmitted by the pipelines comprises mainly methane (89.55~96.33 mol%). The composition of the gas is such that no internal corrosion is expected. The maximum operating pressure of the gas launcher facility at the LNG Receiving Terminal at Cheng Tou Jiao, Shenzhen will be 90 barg while the normal gas temperature at the inlet of the pipeline will be 0 to 5 deg C. The length of pipelines in Hong Kong waters in 28.5 km with an additional 3 km in Mainland waters.

Operational Features of the Pipelines

The pipelines will be designed to accommodate an intelligent pipe inspection gauge (PIG), which will be performed on a routine basis (normally once every 10 years). As part of the Project a pigging station and an emergency flare will be located within the GRT at Cheng Tou Jiao, PRC.

3.3 GAS RECEIVER STATION CONSTRUCTION & OPERATION

3.3.1 Construction

The facilities required in the GRS are as described in Section 3.2.1. Most of the equipment required will be delivered to site in condition ready to be intergrated into the rest of the facilities. The construction work on site in the GRS is minimal and will not result in adverse impacts to the environment. The main activities are:

* Foundation works

* Utilities works (drains, power supply, instrument air and firewater)

* Pipe supports

* Piping runs, welding & etc.

* Testing and Commissioning

3.3.2 Operation

During operation the GRS will utilise heat from steam/hot water within the existing gas production plant to warm the natural gas. The heating system will be designed to integrate with the existing production plant so that the existing allowable quantity and quality of emissions does not require any changes, neither the location of the emission discharge points. As a consequence of this, it is not necessary to examine operational air quality impacts.

3.4 PIPELINE INSTALLATION METHODOLOGY

Kvaerner E&C Singapore Pte Ltd has conducted a Front End Engineering Design study for the Project. Details from the study concerning the construction methodology for the pipelines are presented below, covering both the onshore and submarine works, and shall be finalized at the detailed engineering design stage.

3.4.1 Onshore Section of Pipelines

The pipelines would be buried in a single trench, as far as practicable, approximately 2 m in width (the pipelines would be laid 600 mm apart) and to a minimum cover of 1.1 m. An open cut method of construction would be used. It is expected that the pipelines would be installed such that 50 m sections would be occupied at a time. The total duration of the construction works within the park area would be about 6 months and would be designed to accommodate an open walkway along the waterfront to allow for access by pedestrians. The onshore route and design for the onshore sections is provided in Figures 2.2b and 3.4a.

The environmental implications of the onshore construction works are mainly to water (site run-off) and air quality (dust), which are discussed in Sections 4 and 10 respectively. The excavated materials will be balanced on-site to backfill the pipeline trenches and as the trenches are on reclaimed land there will be no impacts to ecology or heritage resources.

3.4.2 Submarine Section of Pipelines

The proposed design is a bundle configuration (Figure 3.4b) with the twin pipelines installed in a common trench. The bundle configuration is recommended because it allows the twin pipelines to be constructed simultaneously in a narrower trench. This minimises the disturbance to marine activities and the marine environment during construction.

The entire bundle has been designed with a 3 m cover and without altering the original seabed level in accordance with the Marine Department's requirements. At certain locations where the water depth is less than 18m, the pipeline will be backfilled with armour rock to provide additional protection. The Civil Engineering Department (CED) requires that pipelines installed in waters of a depth less than 18m are buried to 3m and provided with adequate protection against future maintenance dredging or alternatively buried at 5m below seabed. Burial of a bundle lay pipeline configuration at 5m below the seabed cannot be achieved using a jetting machine and would entail dredging a trench. This method was not selected due to the environmental concerns of dredging large sections of the pipeline route within Tolo Harbour. The Hazard to Life section of this EIA Report (Section 8) has indicated that certain sections of the pipelines alignment are at moderate risk of damage from anchor drop/drag (3). In these sections the above protection measures have been recommended. However, along one section of the alignment in Hong Kong waters, where large ocean going vessels travelling to Yantian Port cross the pipelines route, Towngas intends to provide additional protection (above and beyond those discussed above). This protection is in the form of a 2 m rock armour cover in a dredged trench. In summary, there are three types of protection proposed for the bundled pipeline, as follows:

* 3m burial with natural backfill (Type 1);

* 3m burial with 1m Armour Rock Protection (Type 2);

* 3m burial wide bottom trench with 2m Armour Rock Protection (Type 3).

Trench Type 1 (Figure 3.4b) is designed to protect against trawling activities and small anchors. This protection is applied generally throughout the route selection. Trench Type 2 (Figure 3.4b) is designed for Type 1 hazards (ie trawling and small anchors), with additional protection against dropped objects. It prevents damage to the bundle due to future dredging works. This protection is provided only in HKSAR waters at depths less than 18m (as per the CED's requirement)(4) .

Trench Type 3 (Figure 3.4b) provides maximum protection to the bundle. It is designed to protect against both Type 1 and Type 2 hazards, with additional protection against accidental anchor drop and drag by seagoing vessels. This protection is provided at the location where the pipeline crosses high intensity shipping areas in Mirs Bay. The locations where these protection types are proposed are indicated in Figure 3.4c.

Pipelaying

The laybarge method is the most common form of pipeline installation. It is a process whereby individual pipe lengths (usually 40 ft) are systematically welded on the laybarge. In the pipelay operation, the laybarge winches itself forward after welding is completed. In relative terms, the pipes, after welding, continue along a ramp for the checking of welds and to the field joint coating station. The pipes then leave the barge and typically, go over a curved ramp known as a stinger before going into a suspended span in the water prior to touching down on the seabed. The curvature of the pipeline in the suspended span is controlled by tension, applied through a tracked or wheeled tensioner system after the welding stations. The two pipes will be bundled together just before entrance to the stinger. The estimated pipelay speed for the bundle configuration is approximately 70 joints per day (40 ft per joint).

Adverse environmental impacts from the pipelaying operations are not *expected to occur as the vessel operators will be required to control and manage all effluent from the vessels involved in pipelaying and a policy of no dumping of rubbish, food, oil, or chemicals will be strictly enforced in accordance with the Waste Disposal Ordinance (Cap. 354), Dumping at Sea Ordinance (Cap. 466) and Shipping and Port Control Ordinance (Cap. 313 and Cap.413).

Jetting and Dredging

The proposed bundle design requires a burial depth of 3m. Two schemes are recommended for burying the bundle. These are jetting and dredging as the sediments along the pipeline route consist mainly of soft marine mud, according to the geophysical and geotechnical surveys conducted in June and July 2002. Jetting is preferred as it does not require off-site disposal of dredged material.

Jetting is recommended for the burial of Type 1 and Type 2 protection. The process is carried out after the bundle is laid on the seabed. It covers the majority of the pipeline route. Dredging is recommended for a 3.6 km section in HKSAR waters, which requires Type 3 protection. This method is selected because a wide trench, which cannot be formed by jetting, is required in order to achieve the necessary protection against large anchor drop and drag. Section 2 has presented a description of the jetting and dredging process.

The jetting process will be conducted at a speed of 1.08 km day-1 (67.5 m hr-1) within Tolo Harbour and Channel (for 16 hours day-1), and within Mirs Bay the jetting machine will progress at a speed of 1.62 km day-1 (67.5 m hr-1) (for 24 hours day-1). In order for the jetting machine to bury the pipelines to a depth of 3 m it will require three separate passes along the pipelines route. The dredging works within the Hong Kong section of the pipelines alignment are expected to take approximately 11 days to complete with the preferred plant, a trailer suction hopper dredger, working at a dredging rate of 11,880 m3 per hour.

The Water Quality Impact Assessment (Section 4 of this EIA Report) has examined the effects of the jetting and dredging on water quality and should be referred to for further details.

Rock Dump

Rock armour is necessary to achieve adequate protection against anchor drop and drag for the bundle configuration. The rock-dumping vessel will manoeuvre to the designated area where the rocks will be dumped. A barge will transport rocks from the quarry to the material storage barge. Rock dumping is not expected to cause adverse impacts to water quality as the material has a very low fines content. Any fines present will be inert and will settle to the seabed soon after rock dumping has finished. Rock dumping could be undertaken down a pipe and consequently the backfill will not pass through the water column. The backfill material, including any fines, will be placed directly on top of the pipes and therefore the affects on water quality will be minor.

Pipeline Crossings

The proposed pipeline route is expected to cross over two existing submarine pipelines. These are illustrated on Figure 3.4c:

* Water Supplies Department (WSD) Twin Submarine Waterline.

* Towngas Naphtha Import Submarine Pipeline.

It is important that the existing pipelines are not exposed to risk of damage during installation of the bundle. Adequate precautions have been planned to ensure that the construction is acceptable.

Based on the Water Supplies Department's (WSD) recommendation, the bundle is designed to span across the existing pipelines with pile support at both ends. The piles are provided to prevent future uneven settlement of the bundle causing unpredicted additional loads on the existing pipeline. These piles are located at the edge of the existing rock berm to provide maximum support to the bundle at the crossings. The outline installation procedure for the supported crossing is as follows:

1) The natural layer of silt on top of the rock berms shall be jetted away. This will include some minor removal of the rocks at the Towngas crossing.

2) The piling templates shall be lowered to the seabed to mark the pile penetration locations.

3) Surveyor to check the template locations.

4) Piles shall be lowered into the template and piled to the correct penetration depth.

5) The piles shall be cut near the seabed at the required protrusion length. Remaining pile shall be brought back to the support vessel.

6) The pipe support frame shall be lowered into pile. This will be locked by a pin connection.

7) The proposed pipelines will be layed across these support spanning over the existing pipelines.

Additional armour rock shall be used to reinstate the crossing and provide protection to both the new and old pipelines.

The crossing works are not expected to cause an adverse impact to water quality as any sediment plumes generated from the minor jetting works will be small and of lower magnitude than the main jetting works discussed in Section 4. Consequently, given the acceptable nature of the main jetting operations (as discussed in Section 4) it is expected that these minor jetting works will similarly proceed in an environmentally acceptable manner. The underwater noise generated by the sheet piling is not expected to cause adverse impacts either marine ecological or fisheries resources. The rationale for this is that the most sensitive marine fauna of ecological importance to underwater noise are marine mammals, which are rarely sighted in Tolo Channel/Harbour (see Section 6.3 for further details). Although Fish Culture Zones (FCZ) are considered to be sensitive to underwater noise generation, the closest to the piling works is the Yung Shue Au FCZ which is located approximately 2.7 km from the works.

Tai Po Landfall

Based on the site's environmental data and presence of shore protection works, a cofferdam method appears to be the most suitable installation method. A cofferdam consists of sheet piling of an area near the shore. These sheet piles provide a soil retaining structure, which enable excavation to carried out at the shore approach section. Before construction of the cofferdam can begin, the existing seawall breakwater has to be removed. A backhoe dredger will be mobilised to the landfall approach area and remove all the shore protection materials and store them on-site (on a barge). With the completion of removal works, two rows of sheet piles will be installed using a vibrohammer. Once the sheet piles are in place, the dredging work can commence. The dredging will continue until the design beach approach profile is achieved. The pipeline initiation operation can then commence to bring the bundle to shore. Material excavated during the dredging works will be stored on the barge and used to backfill the trenches. The water quality impacts associated with this work are detailed in full in Section 4.6.2.

Piggable Wye

A piggable wye assembly, which is also referred to as a subsea tee, will be installed after the bundle configuration has been installed but before jetting. The assembly will be loaded onto the diving support vessel (DSV) and the DSV mobilised to the site at the appropriate time. The piggable wye assembly will be lifted by the DSV and diving crew and be lowered to its position on the seabed by the DSV crane, guided by divers. Minor remedial jetting work will be undertaken to level the pipe ends and create a suitable trench slope between the pipe ends and the respective tie-in assembly flanges. The installation of the piggable wye will not involve off-site disposal of sediments and is expected to cause very minor and transient impacts to water quality through suspended sediment dispersion, which is not expected to breach the WQO or affect any of the water quality sensitive receivers. The details of the piggable wye are presented on Figure 3.4b and its location is shown on Figure 3.4c.

Project Programme

The construction of the Project is scheduled to commence in the final quarter of 2004 for completion by the end of 2005. The construction period is around 12 months for the entire construction, in which dredging, pipelaying and jetting will be conducted in sequential stages. The tentative construction programme is presented in Figure 3.4d. It should be noted that the timeline presents predicted timeframes for each works component. The water quality assessment (detailed in Section 4) has, however, assumed a more accelerated rate of working as a worse case assessment option.

3.5 CONCURRENT PROJECTS

At present there are no planned marine projects that could have cumulative impacts with the construction of the pipelines. At the LNG terminal at Cheng Tou Jiao there will be dredging works for an access channel and turning circle within Mainland waters. To avoid congested marine traffic at the same location and possible damage to the submarine pipelines post installation, none of the aforementioned marine works will take place at the same time as the pipe laying work. The Hongkong Electric Company's (HEC) pipeline will pass close to the Towngas pipeline route, but the construction for the HEC pipeline will not occur concurrently with that for the Towngas pipeline due to the limited working area preventing simultaneous works. ERM has, however, conducted an assessment of the water quality impacts of the two projects being constructed simultaneously (ie Towngas pipelines and HEC pipeline). The findings are presented in Annex B and indicate that no adverse impacts would be expected.

The Civil Engineering Department is planning minor reconstruction works for a public ferry on the island of Tung Ping Chau. Although a detailed programme is not available it is possible that the works will overlap with the pipelines installation. However, this is not expected to cause a cumulative impact as the pier reconstruction works are minor in scale and are expected to cause minimal disturbance to water quality that will not extend far beyond the specific works area. There is also a small reclamation being conducted by the Civil Engineering Department at Ma Liu Shiu in Tolo Harbour. The project is due for completion in November 2004 and consequently is not expected to overlap with any of the major marine works for the proposed project.

No other projects are planned to be constructed in sufficient proximity to the Project to cause cumulative effects. In light of the above, cumulative impacts are not expected to occur.

3.6 SCOPING OF ENVIRONMENTAL ISSUES

The impacts associated with the Project are summarised in Table 3.1 and are described in further detail in the following sections. The intention of laying the pipeline at 3 m or more depth within seabed sediments (or underground onshore) is to protect it and to prevent it intruding visually into the local landscape or creating a physical obstruction along the route. From an operational standpoint, the pipeline is not expected to cause unacceptable adverse effects; operational impacts are principally related to the potential hazard to life presented by the pipeline.

Table 3.1 Potential Sources of Environmental Impacts

Type of Potential Impact	Construction	Operation	Remarks
Disruption of water movement or bottom sediment	Ö	X	See Section 4
Liquid effluents	Ö	X	See Section 5
Disposal of spoil material, including potentially contaminated material	Ö	X	See Section 5
Generation of waste or by-products	Ö	X	See Section 5
Impacts on Ecological Resources	Ö	X	See Section 6
Risk of accidents which would result in pollution or hazard	X	Ö	See Section 8
Gaseous emissions	Ö	X	See Section 10
Dust	Ö	X	See Section 10
Endangerment of cultural heritage resources	Ö	X	See Section 11
Noise generation	Ö	X	See below
Night time operations	Ö	X	See below
Traffic generation (marine)	Ö	X	See below
Storage, handling, transport, or disposal of hazardous materials or wastes	X	X
Ö = Possible X = Not expected

3.6.1 Noise

Representative noise sensitive receivers (NSRs) in the vicinity of the pipeline, as defined by the EIAO-TM have been identified. Their horizontal distances from the proposed pipeline are presented in Table 3.3 and the locations of the identified NSRs are shown in Figure 3.6a. The use of powered mechanical equipment during the construction of the Pipelines has the potential to cause noise impacts. With reference to Section 3.4, three construction methodologies (for the three types of pipeline protection) will be employed for the pipeline installation. A typical construction plant inventory is presented in Table 3.2. As the nearest noise sensitive receiver (Pak Sha Tau) is located 400 m from the proposed pipeline corridor, the predicted noise levels would be in the region of Leq, 30 min 54 to 60 dB(A), ie well within the daytime construction noise criteria of 75 dB(A) (Table 3.3). Adverse construction noise impacts are, therefore, not expected and a detailed noise assessment is excluded from this Study.

Table 3.2 Proposed Plant Inventory

Proposed Plant Inventory	TM Ref. No	Unit	SWL/unit	Sub-SWL
Construction Method 1 – for Proposed Protection Method I (Jetted to 3 m, see Figure 3.4c)
Pipe Laying
Laybarge	CNP 061	1	104	104
Anchor handling tag	CNP 221	1	110	110
Line pipe supply flat top barges	CNP 221	3	110	115
Safety vessel	CNP 221	1	110	110
			Total	117
Jetting
Jetter	CNP 061	1	104	104
Safety vessel	CNP 221	1	110	110
			Total	111
Construction Method 2 – for Proposed Protection Method II (Jetted to 3 m plus rockfill)
Pipe Laying
Laybarge	CNP 061	1	104	104
Anchor handling tag	CNP 221	1	110	110
Line pipe supply flat top barges	CNP 221	3	110	115
Safety vessel	CNP 221	1	110	110
			Total	117
Jetting
Jetter	CNP 061	1	104	104
Safety vessel	CNP 221	1	110	110
			Total	111
Rock Dump
Dredger	CNP 063	1	112	112
			Total	112
Construction Method 3 – for Proposed Protection Method III (Dredged to 3 m plus rockfill)
Dredger	CNP 063	1	112	112
			Total	112

Table 3.3 Identification of Noise Sensitive Receivers

NSR	Location	Type of Uses	Area Sensitivity Rating	Approx. Distance (m)
N1	Kwong Fuk Estate	Residential	C	1500
N2	KCRC Staff Quarters	Residential	C	1300
N3	Deerhill Bay	Residential	C	980
N4	Development on Pak Shek Kok Reclamation	Residential	B	900
N5	Wu York Yu Care and Attention Home	Residential	A	1500
N6	Primary School	Education Institution	A	2000
N7	Wu Kai Sha Youth Village	Residential	A	1800
N8	Li Po Chun United World College	Education Institution	A	1500
N9	Village house at Pak Sha Tau	Residential	A	400
N10	Village house at Nai Chung	Residential	A	1950
N11	Village house at Lai Chi Chong	Residential	A	2100
N12	Caritas Siu Tong Camp	Residential	A	1850
N13	Tin Hau Temple – Chek Chau	Place of Worship	A	1800

Should evening and night time construction works between 1900 and 0700 hours or on public holidays (including Sunday) be required, a construction noise permit (CNP) will be required. The Noise Control Authority will consider a well-justified CNP application, once filed, for construction works within restricted hours as guided by the relevant Technical Memorandum issued under the NCO. The Noise Control Authority will take into account adjoining land uses and any previous complaints against construction activities at the site before making a decision in granting a CNP. The Noise Control Authority may include any conditions in a CNP that it considers appropriate. Conditions stipulated in CNPs should be strictly followed. Failure to comply with any such conditions may lead to cancellation of the CNP and prosecution action under the NCO.

Percussive piling is prohibited at any time on Sundays and public holidays and during the weekday evening and night time hours (1900-0700 hours, Monday through Saturday). A CNP is required for such works during the weekday daytime hours (0700-1900 hours, Monday through Saturday). With the construction of the cofferdam at the Tai Po seawall and for the pipeline crossings, it is expected that the use of sheet piling driver will be required. Since the contractor must obtain a CNP for the use of percussive piling and as issuance of CNP by the Noise Control Authority would depend on the application submitted according to the procedures laid down in the Technical Memorandum on Noise from Percussive Piling (PP-TM), a noise assessment with respect to percussive piling activities will not be required (in accordance with the EIAO Study Brief).

3.6.2 Night Time Operation

No night time marine construction works will be required within Tolo Harbour or Tolo Channel. However, the marine construction plant will operate during the evening time period (ie 16 hours day from 0700 to 2300 hours) and consequently the Contractor will need to apply for a CNP to operate within the restricted period. Based on the proposed plant inventory presented in Table 3.2, evening hour construction noise assessment has been undertaken to assess the potential restricted hours noise impacts. The predicted noise levels are presented in Table 3.4.

Table 3.4 Predicted Noise Levels

NSR	Location	Area Sensitivity	Noise Criteria	Approx. Distance	Predicted Noise Levels (dB(A))
		Rating	(Evening)	(m)	Pipelaying	Jetting	Rock Dump
N1	Kwong Fuk Estate	C	70	1500	48	42	43
N2	KCRC Staff Quarters	C	70	1300	50	44	45
N3	Deerhill Bay	C	70	980	52	46	47
N4	Development on PSK Reclamation	B	65	900	53	47	48
N5	Wu York Yu Care and Attention Home	A	60	1500	48	42	43
N6	Primary School	A	60	2000	46	40	41
N7	Wu Kai Sha Youth Village	A	60	1800	47	41	42
N8	Li Po Chun United World College	A	60	1500	48	42	43
N9	Village house at Pak Sha Tau	A	60	400	60	55	56
N10	Village house at Nai Chung	A	60	1950	46	40	41
N11	Village house at Lai Chi Chong	A	60	2100	46	40	41
N12	Caritas Siu Tong Camp	A	60	1850	47	41	42
N13	Tin Hau Temple – Chek Chau	A	60	1800	47	41	42

As indicated in Table 3.4, all the identified NSRs will comply with the evening construction noise criteria.

It is noted that dredging and jetting works within Mirs Bay will take place 24 hours a day and pipelaying may take place 24 hours a day. Therefore night time work will be involved. There is only one NSR within Mirs Bay, which is the Tin Hau Temple on Chek Chau. This temple is only used during daytime hours. Jetting and dredging activities are not predicted to cause an exceedance of the 45 dB(A) criterion at night. Pipelaying activities, if conducted at night, do cause a marginal exceedance of the criterion of 2 dB(A). As the NSR is not used at night time this marginal exceedance is not considered to be of concern.

The Gas Receiver Station will function 24 hours per day; however, as it is located within the Tai Po Industrial Estate and that the nearest NSRs (Fortune Garden) is located more than 600 m from the Tai Po Industrial Estate, no adverse environmental impact is envisaged to arise from the night time operation.

Regardless of the results of the construction noise impact assessment for restricted hours, the Noise Control Authority will process the Construction Noise Permit (CNP) application, if necessary, based on the NCO, the relevant technical memoranda issued under the NCO, and the contemporary conditions/situations.

3.6.3 Traffic Generation (Marine)

It is estimated that the marine construction works will involve the following vessels:

* During shore approach works (Tai Po Landfall): one barge mounted dredger and one hopper barge.

* During pipelaying: one laybarge, 2 anchor handling tugs, 3 line supply flat top barges with tugs, 1 safety vessel.

* During jetting: one barge deploying the jetting machine as a remotely operated vehicle.

* During dredging (Mirs Bay only): one trailer suction hopper dredger.

A Marine Impact Assessment (5) has been performed in accordance with the requirements of the Marine Department and concluded that no adverse impact is expected from the construction works.

3.7 ENVIRONMENTAL CONDITIONS IN ABSENCE OF THE PROJECT

The Gas Receiver Station (GRS) will be located within the boundary of the Towngas Gas Production Plant, which is within the Tai Po Industrial Estate. The particular piece of land on which the GRS will be built is zoned for industry and is surrounded by other industrial uses. In respect of the ecology of the area, the land has no ecological value, having been created using public fill.

The proposed pipelines pass underneath Tolo Harbour, Tolo Channel and north eastern waters. The area within the pipelines alignment is not known to give rise to notable benthos of significant abundance and diversity. Abundant corals do, however, fringe the coastal areas of Tolo Channel and Mirs Bay. The selected pipelines alignment is proposed to connect to the GRS with the LNG Terminal in Shenzhen. The selection of construction methods, sequencing and alignment, as discussed in Section 2, is not predicted to cause unacceptable environmental impacts from the installation or operation of the pipeline. Once installed on the marine environment the pipelines will be buried 3 m below the seabed and on land with a minimum cover of 1.1 m and, consequently will cause no visual or physical intrusion into the surrounding environment.

Reducing the potential for impacts and maintaining the existing environmental conditions as far a possible has been a major objective of the assessment and in the selection of the preferred pipelines route.

The proposed gas pipelines system would be used to supply natural gas as an alternative feedstock from the Cheng Tou Jiao Gas Receiving Terminal to produce gas at the existing production plant. As such if the Project were not to proceed Towngas would continue to reply on a single source for Towngas, ie tankers of Naphtha.

The alternatives assessment and the previously components of Section 3 present the most preferable option environmentally as well as in terms of programme and operational aspects. Subsequent sections of this report demonstrate that the Project is environmentally acceptable.

________________________________

(1) IGE/TD/1, "Steel Pipelines for High Pressure Gas Transmission", Edition 4, 2001

(2) ASME B31.8, "Gas Transmission and Distribution Piping System". 1999 Edition.

(3) In the Project Profile submitted on 31st October 2001 marine areas of high risk would be protected. However, the Hazard to Life (Section 8) has indicated that no "high risk" areas are present.

(4) This form of protection is also used at the shore approach at the Shenzhen coastline.

(5) BMT Asia Pacific (2002). Marine Impact Assessment of the Construction of the Proposed High Pressure Submarine Gas Pipelines from the Cheng Tou Jiao LNG Receiving Terminal to Tai Po Gas Production Plant.