The rail company said rail operations resumed late Sunday, allowing some of the cars involved in last week's accident to be reset and moved.
"Over the next day or two, product will be removed from the remaining cars," the company said in a Sunday statement. "Once complete, those cars will then be moved out safely."
Some of the rail cars involved in the accident were carrying crude oil from the Bakken reserve area in North Dakota to a Virginia refinery. U.S. regulators in January warned Bakken crude oil may be more flammable than other grades.
Three railcars involved in the accident caught fire, though no injuries were reported from the accident.
CSX said last week it pulled two railcars from the James River.
"CSX also is continuing its comprehensive environmental assessment and protection effort," the company said Friday.
A small amount of oil was reported spilled into the waterway.
Industry officials said the increase in North American oil production from shale reserves has put a burden on existing pipeline capacity, forcing some energy companies to look to rail as an alternate transit method.