At the Minimising Construction Waste conference in London, it also emerged that 30% of all construction resources were sent to landfill unused.
Environment Agency waste programme manager Ralph Crouch told delegates that while most contractors were aware they had a duty of care for waste management, 70% didnt know what it was.
To reduce the amount of construction waste dumped illegally, Crouch suggested that building firms begin electronically tracking their waste.
He said: Thirteen of the countrys biggest building companies have said they would like to take part in an e-tracking trial. We just need the funding now.