The US Environmental Protection Agency's (EPA) Center for Public Health and Environmental Assessment (CHPEA) in the Public Health and Environmental Systems Division (PHESD) is currently engaged in research aimed at developing a measure that estimates overall environmental quality at the county level for the United States. This work is being conducted as an effort to learn more about how various environmental factors simultaneously contribute to health disparities in low-income and minority populations, and to better estimate the total environmental and social context to which humans are exposed. This dataset contains the finalized Environmental Quality Index (EQI), and an index for each of the associated domains (air, water, land, built environment, and sociodemographic environment). Indices are at the county level for all counties in the United States for 2006-2010. More information about the EQI can be found at https://www.epa.gov/healthresearch/epas-environmental-quality-index-supports-public-health