How to reduce the gap between predictions of the amounts of soil requiring remediation – at the diagnostic stage – and those that are actually cleaned up at the remediation stage? This is the main issue that professionals have to face in a large number of brownfields regeneration projects. A study was funded by the Record Association to do a feedback on 23 industrial sites that were already remediated. The goal was to analyze the elements contributing to the discrepancy between predictions and final remediated volumes, and to provide advice for more reliable estimations. A paper was written by eOde, Geovariances and Record in the magazine of the Union des professionnels de la dépollution des sites (UPDS) to sum up the main lessons learned from this study to limit the risks of over-or under-estimation. Paper to read online here.