A 46 car CN Rail coal train derailed 25 kilometres west of Houston last week.
While there was no injuries as a result of the accident, it is estimated that clean up efforts could take several weeks.
B.C. environmental officers said that it appears no spilled coal or train debris had damaged Dockrill and Emerson Creeks or the Bulkley River.
The line was reopened within 36 hours of the accident.