Officials with Phillips 66 refinery in Billings have reported the cause and initial investigation that led to a series of fires with black smoke that belched into the skies on Feb. 9.
In reports submitted to the Montana Department of Environmental Quality and obtained through a public information request, senior environmental consultant Matt Evans of Phillips 66 said hydrocarbons that should have been cleared during the “coking process” — to remove a solid residue — accidentally remained in the refining process too long and the volatile fluids caught a coke pit on fire, not once, but twice, reports the Daily Montanan. Billings residents saw black smoke pouring into a Friday afternoon sky in February, but likely did not notice a second fire later that evening because it happened during the night, against the backdrop of an already dark sky.