Khaw Boon Wan on recycling excavated materials

SINGAPORE: In his latest blog entry, National Development Minister Khaw Boon Wan shared on Friday a little known story of how recycled excavated materials from Singapore’s construction sites are turned into a useful construction resource.

He noted that in most countries, excavated materials are dumped on land, which is unsightly and takes up precious space.

In Singapore, unwanted excavated clay and earth are used to reclaim and create new land. Mr Khaw coined this as "new earth".

Just as NEWater is an inspiring story of how Singapore overcame a shortage challenge, through an innovative way to reduce, reuse and recycle used water, Mr Khaw said such "new earth" is a better way to manage excavated materials.

He said last year, 8.5 million cubic metres of materials were excavated to build basement car parks and shops, underground expressways, and MRT tunnels.

Two main types of materials —— soft clay and good earth —— depending on the location and technique of excavation, are dug up.

With many infrastructure and development projects taking place in Singapore, the construction industry is generating a significant quantity of soft clay and good earth.

Some good earth is reused by the construction industry for their projects. As for soft clay, Mr Khaw said when properly treated, both soft clay and good earth can be used for land reclamation.

Currently, excavated materials from the private construction industry are received at the Changi Staging Ground for transport to Pulau Tekong, where they are reused for reclamation.

Earlier this year, lorry queues at the Changi Staging Ground have grown longer. Some Members of Parliament observed this and raised it in Parliament.

Mr Khaw said the longer queues were due to a spike in the amount of materials generated by the construction industry, causing a bottleneck at the Changi Staging Ground.

A number of large construction projects —— such as South Beach Development at Beach Road, Singapore’s fourth university SUTD, Singapore Sports Hub, and the National Art Gallery —— with deep excavations, came on—stream at the same time.

To increase the handling capacity of the Changi Staging Ground, the authorities have extended the operating hours, added more weigh—bridges, built a stockpile pit, and also worked with contractors to spread out their deliveries to off—peak hours.

These efforts were underway, and the current congestion problem should ease, Mr Khaw added.

— CNA/cc