An EPC (exposure point concentration) is the concentration of a contaminant at the point of exposure. It is used to estimate the exposure dose for a receptor in a risk assessment. The EPC can be calculated using different methods depending on the type and quality of data available. The Risk Assessment Guidance for Superfund (RAGS) Part A provides guidance on how to calculate EPCs for different exposure media and pathways, such as soil ingestion, inhalation of volatiles, and ingestion of groundwater. You can find more information about EPC calculation methods from the first web search result¹. Source: Conversation with Bing, 3/28/2023, from the following sources: (1) Risk Assessment Guidance for Superfund (RAGS): Part A | US EPA. https://www.epa.gov/risk/risk-assessment-guidance-superfund-rags-part Accessed 3/28/2023. (2) Risk Assessment Guidance for Superfund (RAGS) Volume III: Part A - US EPA. https://www.epa.gov/risk/risk-assessment-guidance-superfund-rags-volume-iii-part Accessed 3/28/2023. (3) EPA - Risk Assessment. https://rais.ornl.gov/documents/hhra_regional_supplemental_guidance_report-march-2018_update.pdf Accessed 3/28/2023. (4) Risk Assessment Guidance for Superfund (RAGS): Part E | US EPA. https://www.epa.gov/risk/risk-assessment-guidance-superfund-rags-part-e Accessed 3/28/2023.