Citing numbers from the National Transportation Safety Board, which is leading the probe, the Jacksonville Business Journal said the price tag included environmental remediation costs including coal removal from the site and a nearby creek.
The NTSB has adjusted its estimation regarding the time of the derailment. Investigators feel it occurred slightly earlier, at 11.56pm August 20 instead of the early minutes of August 21 as previously reported.
They have completed the review of the signal systems in the Ellicott City area, and all rail equipment involved has been recovered and inspected.
The NTSB has also wrapped up its train crew, maintenance worker and track inspection personnel interviews.
A preliminary report is expected in about two weeks, the Journal reported, but a more in-depth final report will take at least a year.
Late last week, Howard County police spokeswoman Sherry Llewellyn told the Associated Press the deaths of Rose Mayr and Elizabeth Nass, who died after being buried by coal in the derailment, had been ruled accidental.
The cause of death was compressional asphyxia, a type of suffocation resulting from compression of the chest cavity.
Officials added the two were found buried under coal but still seated on the edge of the bridge where they had just moments before taken Twitter photos of themselves and the view from the overlook.
The pair, both 19, were not hit by the train, Llewellyn said.
So far, investigators have determined that none of the three CSX employees who were on the train activated its emergency brakes, though they were automatically set when the derailment began.
Several other reports have indicated that the train was traveling just 25 miles per hour at the time.
The coal rail shipper has 21,000 miles of rail in 23 eastern US states and the Canadian provinces of Ontario and Quebec.