Elevated Barium Levels in Bedrock, Eastern West Virginia: Cause for Alarm?

McDowell, Ronald R., Avary, Katharine Lee, and McColloch, Jane S.

West Virginia Geological and Economic Survey, Morgantown, WV 26508

Barium is a naturally occurring heavy metal that can have a deleterious effect on the cardiovascular system. EPA drinking water limits for barium have been set at 2 mg/L (~2 ppm).  In 1997, geologists with the West Virginia Geological and Economic Survey began mapping and sampling bedrock, soil, and stream sediment under the auspices of the USGS-sponsored STATEMAP program.  All samples are analyzed by commercial laboratory for barium and 48 other metals.  Investigations have been concentrated in the Valley and Ridge province of eastern West Virginia.  Middle Eocene igneous intrusives were an initial focus of the geochemistry but the study also includes Ordovician through Pennsylvanian sedimentary rocks.  One of the first geochemical trends to emerge was the presence of elevated levels of barium in the majority of samples, regardless of stratigraphic unit.  The background level of barium, from more than 600 samples grouped into 36 stratigraphic categories, is 110 ppm, considerably higher than the acceptable EPA standard.  However, for this to be of concern, one has to demonstrate the transfer of barium from bedrock to drinking water.   Bedrock barium levels were compared to statewide analytical results provided by the USGS Water Resources Division for samples of groundwater, spring water, surface water, stream sediment “fines,” and fish tissue.  Although bedrock barium content may be relatively high, the metal does not appear to move directly into waters in contact with rock.  Rather, barium eroded from bedrock may first enter the hydrologic system in the form of finely disseminated suspended stream load.