Khaw Boon Wan on recycling excavated materials

Julia Ng Channel NewsAsia 10 Aug 12;

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.

(NEWater and New Earth? on National Development Minister Khaw Boon Wan's blog.)

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

Changi congestion woes to ease soon: Khaw Boon Wan
Maria Almenoar Straits Times 10 Aug 12;

The congestion woes in Changi, where there are long lorry queues, is likely to ease soon.

National Development Minister Khaw Boon Wan, noting that MPs had raised this issue in Parliament earlier this year, said that the congestion was caused by the transportation of excavated materials to the Changi Staging Ground.

The area is more congested than usual with lorries as a number of construction projects with deep excavations are in progress at the same time, wrote Mr Khaw in his blog.

Lorries carry excavated materials from various construction projects around Singapore to Changi. The materials are later transported to Pulau Tekong to be reused for reclamation.

He explained that the National Development Ministry has already taken some steps to ease the situation, including extending the operating hours of the grounds and asking contractors to spread out their deliveries of excavated materials to off-peak hours among other things.

Where debris from construction sites goes
Daryl Chin Straits Times 11 Aug 12;

SINGAPORE'S construction workers dug up enough soil, clay and rubble last year to fill 3,400 Olympic-sized swimming pools, it emerged yesterday.

And in a resource-scarce nation, as little of it as possible is wasted.

Instead, a portion of the roughly 8.5 million cu m of debris - gathered from works including underground expressways and basement carparks - was used for projects such as land reclamation, said National Development Minister Khaw Boon Wan.

"In most countries, excavated material is dumped on land," he wrote on his blog. "This takes up precious space and is also unsightly."

Depending on the location of the site and the technique used to excavate, two main types of debris are dug up. One, which is classified as good earth, can be recycled immediately by the construction industry. The other, known as soft clay, has to be treated before being reused, for example in land reclamation.

"Lorries transport these excavated materials from construction sites to staging grounds at our coast," said Mr Khaw.

"There, they are loaded onto barges, which move them to our various land reclamation sites for use as fill material."

A National Development Ministry spokesman said almost 50 per cent of the debris collected - or 3.9 million cu m - was sent to Pulau Tekong for land reclamation.

On his Housing Matters blog, Mr Khaw also addressed recent problems relating to the Changi Staging Ground dumping site. Construction companies have complained of long waiting times - up to five hours - before they can discharge their loads.

Mr Khaw said the queues were caused by a large number of building projects - such as the Singapore Sports Hub and National Art Gallery - which began at the same time.

He added that efforts are being made to resolve the issue. They include extending operating hours, adding more weighbridges and a stockpile pit, and working with contractors to spread out their deliveries to off-peak hours.

Asked if such measures were adequate, Singapore Contractors Association president Ho Nyok Yong said: "The problem seems to be improving slightly but we are still getting many urgent complaints."

Sub-contractor Vincent Ong, who handles the waste dumping for HDB projects, said the queues mean he can make only about three trips a day to the Changi site, down from around eight last year. "As a result, I'm now telling my guys to go to other dumping sites," he said.