Chemicals in Elk River Spill Lingered Longer, Traveled Farther:

CHARLESTON, W. Va. -- A year after the January 9, 2014 chemical spill on the Elk River that affected the drinking water of 300,000 Charleston area residents, scientists continue to provide new information to increase understanding of the chemicals in the spill and how they traveled through the water system.  

A new study led by the U.S. Geological Survey and published online in the journal Chemosphere, examined river and tap water samples at several locations impacted by   the spill.  It is among the first studies on the spill to be published.

Among the findings, some of which informed other recently published studies:

• The primary spill component, 4-methylcyclohexane methanol, or 4-MCHM, was still present in the Elk River at low concentrations six days after the spill began.
• The spill plume traveled at least 390 miles downriver from the spill location to the Ohio River at Louisville, Kentucky. This distance represents a larger geographic area and population than the Charleston area that experienced many of the reported impacts of the spill.
• 4-MCHM was present in Charleston tap water more than six weeks after the spill began. Concentrations decreased throughout the testing, but were always present at some level.
• Another component of the spilled material (a form of methyl 4-methylcyclohexanecarboxylate) -- previously unreported -- was detected in Ohio River and Charleston tap water samples.  This component has a pungent, somewhat sweet/fruity odor unlike the licorice-like odo characteristic of 4-MCHM, and likely contributed to the tap water odor complaints of Charleston residents.

 This is the first study to report concentrations for each of the two chemical forms of the primary spill component (4-methylcyclohexane methanol, or 4-MCHM) in water samples.  The significance of this is that these two distinct forms have unique properties and odors, and knowing this information will inform other studies looking at various potential impacts of the spill.  

 “This spill represented a huge challenge for all of the entities who responded to it, as the behavior of these specific components in water environments was largely unknown before the spill,” said Bill Foreman, a USGS research chemist and lead author of the study. “Researchers had little information on how the spilled chemicals moved through water, their stability or toxicity, or even how to measure them, as published information was either limited or non-existent.”

 One key contribution of the study was a method, developed by scientists at the USGS in collaboration with chemists from West Virginia University, that was able to determine both chemical forms of 4-MCHM to concentrations less than 0.5 part-per-billion.  Measurement at these low concentrations is critical to understanding 4-MCHM behavior in the environment and in drinking water systems, and because Crude MCHM, part of the spill material, has a low odor threshold that people can smell at less than 1 ppb.

Citation for the pre-print article published online open access is:

Foreman, W.T., Rose, D.L., Chambers, D.B., Crain, A.S., Murtagh, L.K., Thakellapalli, H., and Wang, K.K., 2014, Determination of (4-Methylcyclohexyl) methanol isomers by heated purge-and-trap GC/MS in water samples from the 2014 Elk River, West Virginia, chemical spill: Chemosphere, http://dx.doi.org/10.1016/j.chemosphere.2014.11.006.