Hong Kong waste solution

Millions of tonnes of recyclable inert construction and demolition waste piled up in the territory’s landfills, should be put to use in the mainland for reclamation and road works, some building trade experts said. "This is creating a big problem for the construction industry,’’ said Thomas Tang, environmental consultant and senior advisor to the Business Environment Council. "The waste is accumulating and will become unusable.’’

Construction and demolition waste, which accounted for 38 per cent of the total waste dumped in landfills in 2003, can be separated into inert (reusable) and non-inert waste, Tang said. Inert waste refers to soil and rock, of which a large quantity is not reused because of the dwindling number of reclamation projects in the territory. The general practice is for contractors to separate the inert material from steel, taps, pipes and doors, which can be exported without difficulty, when a building is taken down. The inert material is reusable but an increasing amount is collecting at open landfills.

Hong Kong produced 20.5Mt of construction and demolition waste last year. While most of this - 18.1Mt - was inert and dumped at public landfills for reuse, five million tons are still unused, Tang said. Last year’s unused waste adds to one million tons of leftover inert waste in 2002 and eight million tons in 2003. All of it was dumped at the Tuen Mun and Tseung Kwan O landfills. “If we export this to the mainland it’s not waste anymore but a resource,’’ Tang said.

“We’re not saying we will dump hazardous, problematic waste over the border,’’ Business Environment Council chief executive Andrew Thomson said. He said the waste would provide much-needed material for cement and road construction in a resource-hungry market. It’s technically feasible to use the waste to build roads, Thomson said, adding the waste could be exported raw or reprocessed.

The construction sector has responded favorably to proposals to export construction and demolition waste, because it would mean saving waste disposal charges of HK$125 per tonne, set to be introduced this year.