This aerial photograph shows the Freedom Industries tank farm along the Elk River in Charleston. The arrow identifies Tank 396, which leaked the coal-cleaning chemical Crude MCHM into the river on Jan. 9, contaminating the drinking water of 300,000 West Virginians for weeks.

CHARLESTON, W.Va. -- Cleanup crews at Freedom Industries are still several weeks away from emptying all of the site's chemical storage tanks, and still don't have a clear idea of how much of which materials could have contaminated soil at the site.

The West Virginia Department of Environmental Protection is overseeing the cleanup, which is being carried out by Freedom Industries and contractors for the chemical company.

Mike Dorsey, director of emergency response and homeland security for the DEP, said he hopes remediation of the facility might be completed by late spring. However, state and federal government officials remain unsure of the extent of contamination in a key part of the site.

The area around the chemical tanks in the northern end of the site -- including Tank 396, which leaked Crude MCHM into the Elk River on Jan. 9 -- has yet to be fully investigated, largely because the eight chemical tanks there haven't been removed.

U.S. Attorney Booth Goodwin is conducting a criminal investigation of the leak. The U.S. Chemical Safety Board also is examining the incident. Neither agency has completed its work in that area, Dorsey said, but those investigators should finish in the area soon.

"The sooner we can get in there, the better," Dorsey said in an interview last week.

Until the tanks are removed, he said, it's impossible to judge the extent of soil contamination or to know how much remediation must be done to clean up the area.

"The stuff was flowing around underground and who knows where," Dorsey said. "I don't expect to find large quantities of it, but I expect to find some."

The presence of more MCHM in the soil at the site not only will require additional cleanup, but that work likely will bring with it more of the licorice-like smell Charleston residents have become familiar with since the Freedom Industries leak.

See more here:

Freedom Industries cleanup advances