A Technical Assessment Group (TAG) was set up to advise on rehabilitation options, and a much more extensive clean up program was initiated. The TAG Report plan was approved in 1991. Work commenced on site in 1996, and was completed in 2000 at a cost of $108 million. In the worst-contaminated areas, of soil and debris were removed from an area of more than , and buried in trenches. Eleven debris pits were also treated with in situ vitrification. Most of the site (approximately was rendered now safe for unrestricted access and approximately is considered safe for access but not "permanent occupancy". "A term", British historian Lorna Arnold noted, "that no one would have applied to these regions 30 or 40 years before". Nuclear engineer Alan Parkinson observed that "an Aboriginal living a semi-traditional lifestyle would receive an effective dose of 5 mSv/a (five times that allowed for a member of the public). Within the 120 km², the effective dose would be up to 13 times greater." The effectiveness of the cleanup has been disputed on a number of occasions.