EDEN, N.C. -

In a letter sent late Tuesday, North Carolina's governor is giving Duke Energy until March 15th to come up with plans to move coal ash ponds away from rivers and into a lined landfill.

The letter references the end of a 60 day notice that the North Carolina Department of Environment and Natural Resources gave Duke Energy to reevaluate its permit to discharge into the state's waterways.

Today WDBJ7 learned federal officials don't know how long it will take to clean up the Dan River.

Vacuum trucks sit high above the river banks in Eden, North Carolina continuously pumping coal ash from the sealed stormwater drainage pipes. The coal ash ponds sit even higher.

Rare video from WDBJ7 from farmland across the river shows their work and the steep climb workers face to access the leaks.

Wednesday workers in hard hats from federal and state organizations used hoses to vacuum the piles of coal ash laying on the bottom of the river. The river still runs high, making that process dangerous.

Myles Bartos with the EPA says the work continues downstream.

"We continue to sample the episodic events actually at the river water treatment plants, Danville, South Boston, and Clarksville. And we're also, when the river allows it, going in to assess areas like the dam," Bartos said in an interview outside the gates of the closed Duke Energy Steam Station in Eden, North Carolina.

On the river, state health regulators test the water quality at the spill and downstream.

The EPA mapped out specific checkpoint locations and compare results.

While teams from the North Carolina Department of Environment and Natural Resources test fish tissue for poisoning.

"We have to drive with what the data says and right now the data says the drinking water that's being delivered to the residents is absolutely safe," Bartos said.

Crews say they'll be cleaning the mess until there is no longer a threat to the Dan River.

A 3D model from researchers, some affiliated and some not with Wake Forest University, shows an aerial view of the pond that collapsed. They used photos from a drone to make the 3D model into a video. (Here's a link to their findings and the video.)

In a more detailed timeline, they estimate 16 to 20 million gallons of water and ash spilled from the ponds on February second with 15 million gallons spewing from the drains in the days following.