In the case of freshwater, the sustainability of the resource can be enhanced through greater efforts to conserve water, use water efficiently, encourage use of seawater systems and "greywater" recycling and reduce leakage from supply infrastructure. Such measures, together with initiatives to protect gathering grounds in Hong Kong will help reduce the SAR's reliance on imported water supplies, which are subject to negotiated agreements with Guangdong authorities, and which are predicted to become less plentiful (due to growing internal demand in China) in future years.

Minerals, Aggregates and Energy - Issues and Trends

• Quarry production of aggregates from four sites in Hong Kong is currently around 17 million tonnes (1996) and significant quantities of marine aggregates are also extracted from the seabed in Hong Kong waters. Future land based mining for minerals has effectively been prevented by competing land uses and development pressures.
• Electricity is supplied from three major power stations in Hong Kong; Lamma and Castle Peak which are coal fired, and the combined-cycle gas turbines at Black Point. The raw material for these plants are imported from throughout South East Asia. Hong Kong is also supplied with Towngas, manufactured locally, and LPG which is imported by sea.
• Between 1988 and 1998, Hong Kong's final energy requirement increased by over 80% to nearly 391,000 TJ. Per capita energy consumption has risen by 30% over the same period. The increasing trend is projected to continue, with a total energy consumption increase of 30% predicted between now and 2010 without demand management or energy efficiency measures.
• Increasing energy use will increase demands on primary energy (natural resources) and increase emissions such as NOx, SOx, CO2 and particulates, though these may be addressed through adoption of cleaner fuels and more efficient generation technologies, a move to which has already begun in Hong Kong, although alternative energy sources have yet to be meaningfully exploited.

Hong Kong is similarly dependent upon imports of minerals and aggregates for building and fossil fuels as a source of energy for transport, homes and electricity generation. To reduce the negative effects of resource extraction (eg habitat disturbance by sand borrowing) and energy use (eg greenhouse gas emissions, air pollutant emissions) on other aspects of the natural capital stock, the increased efficiency of use of these resources, the management of demand and the development of more sustainable sources and technologies can and should be pursued. Policy measures such as DSM, together with cleaner fuel forms of transport and, critically, the education of consumers, can all contribute to this process. Whilst a number of renewable energy technologies (in particular harnessing solar energy to produce hot water or electricity generation) have potential applications here, very little commitment has been made to exploit such technologies. Diversification of the energy sector should be encouraged and its long term planning given greater attention. This should be approached through the development of an explicit and strategic energy policy for the SAR.

Solid Waste - Issues and Trends

• Construction and Demolition (C&D) waste and Municipal Solid Waste (MSW) are the two most significant waste streams in Hong Kong. Although some C&D waste is diverted to public filling areas (the amount diverted depends on availability of such areas), the remainder along with most MSW is currently disposed of to landfill. Most of the SAR's chemical waste is disposed of at the Chemical Waste Treatment Centre at Tsing Yi.

• Due to a growing and increasingly affluent population, rates of domestic MSW are steadily growing and this trend is projected to continue (eg domestic waste arisings are predicted to double 1997 levels by 2015) without actions to address it.

• Landfill space is becoming severely restricted and the Government's Waste Disposal Framework Plan, together with various waste reduction initiatives, have been developed to address these problems. Targets have been set for recycling and waste reduction - including reducing the amount of MSW requiring final disposal in 2007 by 40% - in order to encourage resource efficiency and increase the lifespan of existing landfills. Nevertheless, in the longer term, alternative treatment methods for Hong Kong's waste, including the presently mooted waste-to-energy schemes will need to be adopted.

• Waste disposal also presents environmental pollution issues for example from illegal waste tipping and from land contamination associated with historical industrial and commercial pollution.