The 1990 census was the last nationally consistent survey of a home’s source of water, and has not been surveyed since. The associated larger work presents a method for projecting the population dependent on domestic wells for years after 1990, using information from the 1990 census along with population data from subsequent censuses. The method is based on the “domestic ratio” at the census block-group level, defined here as the number of households dependent on domestic wells divided by the total population. Analysis of 1990 data (>220,000 block-groups) indicates that the domestic ratio is a function of the household density. As household density increases, the domestic ratio decreases, once a household density threshold is met. The 1990 data were used to develop a relationship between household density and the domestic ratio. The fitted model, along with household density data from 2000 and 2010, was used to estimate domestic ratios for each decadal year. In turn, the number of households dependent on domestic wells was estimated at the block-group level for 2000 and 2010. High-resolution census-block population data were used to downscale and refine the spatial distribution of domestic-well usage and to convert the data into population numbers. The results are aggregated to 1km x 1km pixels and presented in two datasets for each decadal year: a BGM (Block Group Method) dataset and an REM (Road Enhanced Method) dataset. This dataset is an estimation of the location and population served by domestic wells in the contiguous United States for 2010.