Southampton-based Cleaning Services Group Ltd (CSG) has developed a system for disposing of chromated copper arsenic (CCA) treated timber.

CCA treated material is unable to be landfilled alongside inert building materials or at non-hazardous material sites due to its use of arsenic. It also cannot be placed in hazardous landfill sites as timber is an organic material, meaning it is left in a “stateless waste stream” according to CSG.

In response, chemists at CSG’s Manchester office have developed a system which shreds the wood, washes it and then treats the resulting residue to create a “cake” that can be sent to hazardous waste landfill sites. The shredded timber can then be disposed through normal landfill or composting.

“Huge volumes of this wood have been stockpiled on our customers’ sites since the introduction of the Landfill Directive because they didn’t know how to dispose of it,” said CSG managing director Paul Quigley.

”We’ve got the infrastructure at our Cadishead site to successfully devise a process for dealing with this disposal problem on an industrial scale by adapting existing shredding and aqueous treatment technology.”

Previous methods of disposing of CCA treated material includes incineration, but CSG said the combined capacity of incinerators with the ability to remove arsenic from off gases is not enough to deal with the volume of CCA treated timber in the UK.