HONG KONG 2005

The Civil Engineering and Development Department (CEDD) manages a comprehensive slope safety system, which has brought about a substantial improvement in the safety of slopes in Hong Kong. This has been achieved by improving slope safety standards and technology, ensuring the safety of new slopes, improving the safety of existing slopes, and providing public warnings, information, education and community advisory services on slope safety.

The department continues to exercise geotechnical control on private sector developments and government projects in the interest of public safety. Professional geotechnical engineers undertake technical audits of geotechnical design submissions prior to construction. In addition, they carry out site audits during construction to assess the standard of implementation of the design and geotechnical site supervision. In September 2005, the department's role was extended to including the geotechnical control of government tunnel works.

In 2005, the department dealt with over 13 000 government and private sector geotechnical submissions and some 4 000 requests for geotechnical advice from government departments and members of the public. It also undertook 2 900 audits of active construction sites, with over 90 per cent of all active construction sites with geotechnical site supervision requirements being audited at least once during the construction period.

The department maintains a continuing Landslip Preventive Measures Programme to ensure the safety of existing slopes. In 2005, about $900 million was spent on the programme. Upgrading works were completed on 285 government slopes and all were landscaped to blend them with the surrounding environment. In addition, safety screening was completed on 310 private slopes.

The department inspects substandard slopes to identify those especially vulnerable to landslide risk, recommends clearance of any squatter structures which are affected and advises the occupants to seek safe shelter during heavy rain. In 2005, it inspected about 100 substandard slopes and recommended clearance of squatters affected by these slopes.

The Slope Information System, set up and maintained by the department, contains pertinent technical information on 57 000 sizeable man-made slopes in Hong Kong. A bilingual version of the system has been uploaded to the Internet at the department's Hong Kong Slope Safety website. Together with the Slope Maintenance Responsibility Information System maintained by the Lands Department on the Internet, the public can have ready access to information on slopes under their responsibility.

In sustaining public awareness of slope safety, the department continues to promote and disseminate slope safety and slope maintenance messages to the public. During the year, roving exhibitions were held in nine venues — three secondary schools, two universities, a public and a private housing estate, a commercial shopping centre and Hong Kong Central Library.

A book on the landslide history of Hong Kong, When Hillsides Collapse — A Century of Landslides in Hong Kong, was published by the department to raise public awareness of landslide hazards. The book was based on the information collected from the landslide history exhibition held in 2004 plus some related interviews and aerial photographs.

In March, the department joined forces with the Security Bureau, Drainage Services Department, Hong Kong Observatory, Information Services Department and Hong Kong Red Cross to launch a year-long public education programme, Safer Living — Reducing Natural Disasters. The programme aims to enhance understanding of natural hazards so that appropriate action can be taken to reduce disasters. The Secretary for Security officiated at the launching ceremony and the opening of an exhibition in March 2005. Other major activities of the Safer Living programme in 2005 included TV programmes — a four-episode Safer Living series and the eight-episode Meteorological Series III — a tropical cyclone name-nomination contest, six popular science lectures, a seminar on natural disaster reduction and a slogan and bookmark design contest. In addition, a dedicated website (saferliving.info.gov.hk) was set up to give easy access to information on the programme.

The Community Advisory Unit of the department continues to provide useful advice to private slope owners to help them maintain and improve the condition and appearance of their slopes. The department audits maintenance works of government departments to help in their slope maintenance work. Audits of government slope works help ensure a continuous improvement in the overall state of maintenance.

It also maintains a 24-hour, year-round emergency service to provide geotechnical advice to government departments on action to be taken to protect the public against landslide danger. Due to heavy rainfall, some 450 landslide incidents, caused by heavy rainfall, were reported in 2005. The department's Emergency Control Centre was mobilised twice, and over 180 staff were deployed to provide emergency services to remove danger posed by landslides and to help restore essential services to the community.

The department conducts various studies to improve the knowledge and practice of dealing with natural terrain landslide hazards. It has applied remote sensing techniques and Geographic Information System analysis to identify historical natural terrain landslides and quantify the landslide risk. The department is also enhancing the existing Natural Terrain Landslide Inventory by incorporating information obtained from interpretation of the available aerial photographs.

The department produces geotechnical guidance documents to disseminate new technological development findings and improved design and construction practices including improved guidelines on the design and construction of soil nails.

The Geotechnical Information Unit in the Civil Engineering Library, which houses the largest collection of geotechnical data in Hong Kong, served about 30 000 public users during 2005.

The department provides specialist geotechnical services to government departments, including the provision of ad hoc geotechnical advice, feasibility studies, detailed investigations, design and construction supervision for a wide range of public works projects. The projects handled by the department during the year included site formation works at Sunny Bay Salt Water Service Reservoir on Lantau Island, foundation works at Sheung Wan stormwater pumping station and sewer pipe jacking and sewage pumping station foundation work at Kam Tin and Au Tau.

In addition, the department provides construction material testing and ground investigation services to support public works projects. The testing service is provided by the Public Works Laboratories. During the year, some 900 000 tests were carried out and 19 000 metres of soil and rock drilled.

The department enforces legislation relating to mining, quarrying and explosives, and administers quarrying contracts. It processes applications for the manufacture, storage, conveyance and use of explosives, and inspects stone quarries, blasting sites and explosives stores.

Hong Kong consumed about 12 million tonnes of aggregates and other rock products in 2005. About 50 per cent of its demand for the products was met locally, with the balance imported from the Mainland.

Three quarrying contracts were in force during the year. The quarrying contracts require the operators to rehabilitate the quarries within a specified period in return for the granting of rights to process and sell surplus rock excavated during the course of the works. The rehabilitation works involve recontouring and extensive planting to blend the quarries with the surrounding hillsides.

The department manages two government explosives depots at Kau Shat Wan on Lantau Island and Piper's Hill, Sha Tin, which provide bulk storage facilities for imported explosives for industrial use. It also undertakes the delivery of explosives from the depots to blasting sites and issues shot-firer certificates. About 2 700 tonnes of explosives were consumed in 2005, used for quarrying and site formation works.

The department also provides technical support to the Home Affairs Bureau and the Marine Department in assessing applications for fireworks displays.

About 21 million tonnes of construction and demolition (C&D) materials generated by local construction activities were handled during the year. Of this, about 19 million tonnes of inert materials were re-used as fill material in projects such as Penny's Bay Reclamation and Central Reclamation Phase III developments, or stockpiled at the fill banks in Tuen Mun and Tseung Kwan O. The department, on behalf of the Public Fill Committee (PFC), manages construction and demolition materials and utilisation of land-based fill reserves. Public construction works are required to adopt waste-management plans that reduce the generation of such materials at source.

In 2005, about 2.2 million cubic metres of uncontaminated mud and 800 000 million cubic metres of contaminated mud were generated by various works projects and maintenance works on navigational channels in the harbour. Uncontaminated mud was disposed of at open sea floor disposal grounds or exhausted marine sand borrow pits. Contaminated mud was placed in specially selected and closely monitored exhausted sand borrow pits, which were then capped with clean mud on completion of filling to isolate the contaminants from the environment. The use of exhausted sand borrow pits for mud disposal is preferred as it has the dual benefits of providing much needed disposal capacity and restoring the seabed to its natural profile and state.

The CEDD is additionally responsible for managing disposal facilities for dredged and excavated sediment, and identifying and managing the supply of marine fill resources for development projects on behalf of the Marine Fill Committee.

The department also maintains a Fill Management Database on fill requirements, mud disposal and surplus excavated materials from major public and private projects to help the construction industry coordinate sources of fill materials and make the best use of surplus materials. All project data are available at the department's home page (www.cedd.gov.hk).

In connection with the management of Hong Kong's fill resources and mud disposal capacity, the department continues its geotechnical, environmental and ecological studies and monitoring to examine the effect of the dredging and disposal activities, and to investigate possible ways to minimise the impact on the marine environment.