Waste not want not

Grading and treatment of soil prior to reuse

Norfolk County Council is achieving cost savings of nearly £1 million just by managing construction waste better. Other local authorities are taking notice.

(Article taken from our customer magazine, Momentum)

The old saying “where there’s muck there’s brass” is being given a modern twist in Norfolk, UK, where the county council has prepared for new waste management legislation with a rigorous policy of reuse, recycling and reduction.

Early in 2008 it will become mandatory for every UK construction project valued at £250,000 or more to produce a site waste management plan. They are voluntary at present. Currently the construction and demolition industries generate 120 million tonnes of waste per year, around a third of the UK total. The government wants to curb the volume sent to landfill by requiring each developer to set out plans for reuse, recycling and reduction, and to predict the types and quantities of waste. Volumes produced will be compared against those anticipated.

“The strength of a site waste management plan will become pivotal to the success of future planning applications,” says Mott MacDonald environmental scientist Emma Maltby.

“Developers caught dodging their waste management obligations, by fly-tipping or passing a hazardous material off as non-hazardous waste, for example, will be liable to increasingly severe fines or prison sentences.” Norfolk County Council has responded to the legislation by treating it as an opportunity rather than a burden and demanding a site waste management plan for every project it undertakes.

Over the course of the last year the results have been dramatic, reports Mark Sexton, Norfolk’s project manager for the waste management plan. The council has formed a partnership with Mott MacDonald and contractor May Gurney, which together deliver highways capital and maintenance projects for the council. Norfolk has pioneered its waste management strategy on road schemes, where it is saving £200,000 to £300,000 per year on a total £60 million roads budget.

“We generate well in excess of 80 000 tonnes of waste from highways works each year,” Sexton says. “Virtually all of that has the potential to be reused or recycled, but until recently 40,000 to 45,000 tonnes went to landfill. “We’ve found that some waste is reusable in it’s original form. We have worked with the Environment Agency on the reclassification of materials, which has enabled us to avoid sending particular types of material to the tip. If a material can be reused without being processed it is not classed as waste at all, which makes it possible to reuse soils, for example.

Maltby says: “Then there is concrete and asphalt. They can be crushed and recycled as sub-base material for road construction. That reduces the need for imported aggregate.”

“Big chunks of waste concrete and asphalt have in the past been given to companies who have crushed them and then sold the reconditioned materials back to us,” Sexton continues. “We were buying back our own waste. We are now crushing material ourselves.”

Money paid in landfill charges has been slashed. Transportation costs are down. Less virgin material is being ordered. And more care is being taken to order the correct materials in the right quantities.

There is a perception in the construction industry that the cost of writing and implementing a site waste management plan is only recouped on larger projects – hence the £250,000 project value threshold set by the government. But Sexton says Norfolk’s best saving to date has been on an £80,000 footpath, on which careful waste reduction cut the out-turn cost by 10%. “On the other hand we have schemes where there’s no direct financial saving but our environmental performance is improved,” comments Sexton.

Implementing site waste management plans has improved the overall efficiency of project management, yielding total savings in the order of 1%-1.5%. “That represents £600,000 to £900,000 saved on our highways budget. For local authorities who struggle to fund road maintenance, that’s a significant sum. A number of councils across the country are taking notice.”

Maltby says that there is scope to realise major savings across the construction industry almost immediately. “Of all materials delivered to site, 13% go straight to tip due to over-ordering, damage resulting from poor storage or because the materials ordered are inappropriate.” More attention to detail and better site management could eliminate much of this waste. Waste that cannot be avoided should be segregated into material types on site. “The excuse that there’s not enough space on site for the different skips needed is often not true. Even on the tightest sites the layout can be restructured to accommodate them.”

Designers need to specify materials that can be easily reclaimed and recycled, she adds. “In the context of waste management, composite materials aren’t good.”

Comprehensive site waste management plans should consider demolition waste when a structure reaches the end of its life, as much as construction waste when the project kicks off. “It’s not difficult to do, but it requires developers and designers to discuss waste management early in the project,” Maltby notes.

Norfolk County Council is working with its environment and waste team to open up construction waste processing facilities to the private sector.

Key sustainability facts

• 13% of all construction materials go straight to the dump
• Site waste management plans eliminate most construction waste
• Potential for major savings through reuse and recycling