File supporting data tables.

Drinking water affordability affects all residents including those with piped water connections and self-supply, private wells. Self-supply drinking water well users make up 12–15% of the United States population and are often overlooked during affordability studies. To the best of our knowledge, this study is the first attempt to quantify statewide water affordability costs for all residents, both utility customers and private well users. This study applies several geospatial methodologies: percent median household income (MHI), number of households beneath affordability thresholds, and hours worked at minimum wage. The greatest determinant of private well affordability was found to be initial capital costs. These costs were represented as a monthly loan payment plus operations and maintenance costs; a range of results were found. For operations and maintenance costs only, 9% of private well serviced homes exceeded the 2.5% MHI threshold while for monthly loan payments, corresponding to a $13,500 capital cost, 51% of households exceeded the same affordability metric. There are 3.17% of centralized water utility serviced households spending greater than 2.5% of their median household income on water while 16.3% of utility-serviced households fall below an income threshold representing 2.5% of the block group MHI. This range of results highlights the need for a multifaceted solution to ensure the human right to affordable water.