Defra has recently published the results of the research project SP1011 - An examination of contaminated land sector activity in England and Wales.
This research project was undertaken by Cranfield University and CL:AIRE in 2014. The report can now be downloaded by following the link: http://randd.defra.gov.uk/Default.aspx?Menu=Menu&Module=More&Location=None&Completed=0&ProjectID=136