Risk Assessment for PCBs in Soils at a Ranch


PCBs originating from a former gas plant had contaminated a nearby cattle ranch in rural Texas.  The State of Texas and EPA have developed risk-based protection standards for PCBs in soils, but not for the land use types occurring at the ranch.  Our objective was to determine if unacceptable risk existed for the current land uses—specifically cattle ranching and hunting—and to communicate our findings to the ranch owners.


We completed an assessment of the potential risks from PCBs under cattle ranching and hunting scenarios.  Our assessment included the development of site-specific parameters that described direct contact with the soil, as well as the consumption of game and cattle that were potentially exposed to PCBs while foraging and grazing.


Our risk assessment provided the technical basis for determining the need for remediation at the ranch.  Our presentation to the ranch owners ensured their understanding and comfort with the methods and results of our technically rigorous evaluation.