Hong Kong will be faced with a shortage of quarry stone used for construction by 2008, when supplies from local quarries and many in Guangdong will be exhausted, a senior works official said. Assistant Director of Civil Engineering David Howells said that in view of the projected shortfall, a review would be carried out in 2004 to gauge demand before the department selected new quarry sites in Hong Kong. During a visit to Shek O quarry, Mr Howells said a study completed in the middle of last year concluded that there would be a shortfall from 2008 onwards. The Hong Kong construction industry last year consumed about 13 million tonnes of quarried building stone, down from 15 million tonnes a year before. Four quarries - Shek O, Lam Tei in Yuen Long, Lamma Island and Anderson Road in Kowloon East - supply half of requirements. The remainder comes from quarries in Guangdong. By 2013 the four sites in Hong Kong would cease operation, although a serious shortfall would not emerge until 2017 when supplies from most mainland quarries would also be exhausted, Mr Howells said. During a transitional period from 2008 to 2017, recycling of used stone from demolished buildings and surplus supplies from works projects could help to satisfy demand, Mr Howells said. 'We will see in 2004 what the demand situation is. If there is substantially excessive demand, we will then need to find new sites. On the other hand, if demand is roughly similar to now, recycling or surplus rocks from other projects may be sufficient.' In the study carried out by the department last year, 20 potential quarry sites were picked, including some in Yuen Long and on Beaufort Island, off Po Toi Island. 'None of these locations quite fits the requirements. They are either environmentally sensitive or not very accessible,' Mr Howells said, citing Beaufort Island as being too close to Po Toi Island, where a coral reef has flourished. Construction stone supplied by Hong Kong sites sells on average for $65 per tonne, about 10 per cent more than mainland supplies. Hong Kong-produced construction stone in general is of higher quality.