Agreement No. CE 55/2000 EIA Study For Construction of Lung Kwu Chau Jetty Civil Engineering Department Final EIA Report 2 PROJECT DESCRIPTION Location and Scale of Project 2.1 The proposed site of the Project is located on the eastern coast of Lung Kwu Chau as shown in Figure 2.1. Lung Kwu Chau is situated within the gazetted Sha Chau and Lung Kwu Chau Marine Park. Due to the remoteness of the site, the island is uninhabited with no infrastructure other than the existing jetty and the Doppler VHF Omni-directional Range and Distance Measuring Equipment (DVOR/DME) Station. The location of the existing jetty is also shown on Figure 2.1. 2.2 The scope of this project comprises the construction of a precast concrete blockwork jetty and a concrete catwalk, dredging of an approach channel, installation of miscellaneous facilities and demolition of the existing jetty. 2.3 A jetty was constructed at nearby Sha Chau to serve the radar station set up by CAD on the island for the new airport at Chek Lap Kok. To date it appears that no environmental concerns have been raised in connection with the operation of this radar station and the assoc iated jetty, which is also located within the Sha Chau and Lung Kwu Chau Marine Park. The structural form of the Sha Chau jetty is similar to that proposed under the preliminary design of the jetty at Lung Kwu Chau, although the jetty at Sha Chau is larger in size. A jetty has also been provided at Siu Mo To to serve the DVOR/DME station located there. Construction and Operational Activities 2.4 The major activities involved during the construction stage of the Project are dredging for foundation of the je tty and catwalk and approach channel, preparation of precast concrete blocks, laying of rock bedding, setting of precast concrete blocks, construction of concrete catwalk, extension of an existing footpath, installation of miscellaneous facilities (handrailings, bollards, fenders, navigation light, tide gauge and marine notice boards) and demolition of the existing jetty. A maximum production rate for the dredging works is 500 m3 per day and it is anticipated that only one dredger will be working on-site at any time. 2.5 The main construction activities include: i. Trenches for the foundations of catwalk and pier head will firstly be dredged. ii. Rock fill will then be deposited to the foundation trenches to form the rubble mound to the jetty structure. iii. For the catwalk, concreting work above the rubble mound will be carried out during low tide. iv. For the pier head, precast seawall blocks will firstly be placed and then concreting on deck surface will be carried out above seawater. v. Approach channel to the jetty will be dredged. vi. Demolition of existing jetty. vii. Extension of an existing footpath. 2.6 During the operation stage, the only activities at the proposed jetty will be the berthing and mooring of vessels for the purpose of servicing and maintaining the DVOR/DME station F:\PROJECTS\A15500\reports\Final EIA\Sect_2.doc 2-1 MAUNSELL Agreement No. CE 55/2000 EIA Study For Construction of Lung Kwu Chau Jetty Civil Engineering Department Final EIA Report and for emergency repair work, and maintenance dredging of the approach channel. The frequency of maintenance dredging is estimated to be 5 years. Maintenance dredging would be carried out at areas where results of sounding survey show that the seabed level is too shallow for navigation. Project Programme 2.7 The construction of the Project is scheduled to commence in March 2003 for completion in December 2003. The construction period is 10 months for the entire construction, in which about 3 to 5 months are for dredging and marine foundation works. Dredging for both the approach channel and the foundation of catwalk and pier head is estimated to take around 2 weeks each to complete. These durations include the time required for plant mobilization and sounding surveys before and after dredging, and therefore the actual duration of dredging works will be less. The tentative construction programme is presented in Figure 2.2. 2.8 It is expected that this Project has no major interaction with other projects. Need of the Project 2.9 The DVOR/DME Station on Lung Kwu Chau was commissioned in April 1996. The station provides tracked guidance on bearing and distance information to the aircrafts approaching and departing from the Chek Lap Kok Airport. 2.10 The existing ruined and abandoned jetty at Lung Kwu Chau is too small and the water depth too shallow to permit access of CAD’s repair vessels for the routine servicing and maintenance of the DVOR/DME Station being operated on the island. Reconstruction of the exis ting jetty at Lung Kwu Chau is also required to enable the CAD’s vessels to berth at the island and carry out emergency repair work for the DVOR/DME Station. The DVOR/DME Station is an essential navigational aid for air traffic control in Hong Kong, and therefore it has to be maintained regularly and, whenever failures occur, the station needs to be repaired without delay such that normal air traffic control is maintained and flight safety is not compromised. 2.11 At present the transportation of equipment and personnel for servicing and maintaining the DVOR/DME Station has to rely on helicopters. This mode of transportation is not always available, however, especially during night-time, low visibility and/or adverse weather conditions, such as typhoon, rainstorm and thunderstorm situations, for safety reasons. Repair of the equipment at the DVOR/DME Station is usually needed under adverse weather conditions, such as after the passage of a typhoon near Hong Kong, as these are typically the times that equipment failures occur and require emergency visits to the island for immediate recovery actions. Aviation safety is a top priority and no government can afford to leave any aviation equipment damaged without repairing or attempting to repair it at the very first instance. Moreover, there are severe limitations on the use of helicopters as heavy and bulky equipment cannot be transported by helicopters (such as a standby generator which is required for the station). In case of rainstorm or when the typhoon signal number three or higher is hoisted and in the event of any vital navigation aid equipment F:\PROJECTS\A15500\reports\Final EIA\Sect_2.doc 2-2 MAUNSELL Agreement No. CE 55/2000 EIA Study For Construction of Lung Kwu Chau Jetty Civil Engineering Department Final EIA Report failure, CAD’s vessels would travel to Lung Kwu Chau to carry out emergency repair work. This flexibility could not be provided by the present helicopter service. 2.12 With regard to ad-hoc repairing activities for the DVOR/DME Station carried out by CAD, past experience indicates that there could be frequent occasions for urgent or emergency repair incidents (such as equipment/system failures due to lightning strikes, floodings, fire alarms, antenna damages, etc.) that would require daily visits of CAD’s staff to the island over a period of several days. Based on CAD’s records, a total of 216 helicopter trips were made to the station over the past 2 years, with 42 trip s related to emergency repairs. The frequency of using the jetty is expected to be increasing in the coming years in view of the aging of the equipment and systems installed there. 2.13 In addition to providing access for CAD’s vessels whose staff would go t o the station on a weekly basis to carry out routine maintenance activities, it is understood that the proposed jetty may also be used by staff from other government departments. These departments include Fire Services Department, Electrical & Mechanical Services Department, Architectural Services Department, Marine Department, Agriculture, Fisheries & Conservation Department, as well as utilities companies such as PCCW HKT and CLP Power, in connection with their routine maintenance and emergency repair operations for the equipment/building works/building services and electrical facilities associated with the DVOR/DME Station. Consideration Of Alternative Transport Modes 2.14 Lung Kwu Chau is a remote and uninhabited island located in the North Western waters. There are no ferry or kaido services operating to this island. There are only two possible modes of transportation for delivering equipment and personnel to the island for servicing and maintaining the DVOR/DME Station; these being by sea and air. As discussed above, the present transportation mode is largely restricted to air transportation by helicopter due to the poor condition of the existing jetty. However, the use of helicopters is not always available, especially during night-time, low visibility and/or adverse weather conditions, which are typically the times that emergency repair work is required. Therefore arrangement for proper sea transportation to the island is required to provide access to facilitate emergency repair work of the DVOR/DME Station, and thereby maintain aviation safety at Chek Lap Kok. 2.15 Given the remoteness and exposed nature of Lung Kwu Chau there is no shelter and drinking water supply on the island. An option of government staff being stationed on the island during expected adverse weather situations as a precautionary measure, such as during the approach of a typhoon, is not considered to be feasible in view of personnel safety. In addition, the introduction of additional facilities and infrastructure on the island, which is a designated Site of Special Scientific Interest (SSSI), would have the potential for greater environmental impact and disturbance. Construction activities for the provision of infrastructure and facilities would inevitably cause a greater degree of habitat loss and disturbance within the SSSI than the proposed Project.