Keep your head above water: Explaining disparities in local drinking water bills

Rising water bills across the U.S. underscore the need to understand the factors that contribute to disparities in local system bills. In this paper, we examine residential water bill amounts from 1,720 systems in four states in different regions of the U.S. (Arizona, Georgia, New Hampshire and Wisconsin) to (1) examine how local system bills at a constant consumption level (4,000 gallons per month or 15.14m3) for drinking water vary within and across states, as well as within combined metropolitan statistical areas (MSAs), and (2) study the relationship between local system bills and system-level characteristics. We find a high degree of similarity in median bill amounts between states but substantial variation within them at the MSA and local system scale. Our multivariate analysis suggests that municipally-owned systems are more likely to have lower water bills relative to for-profit systems, while factors such as purchasing water and having neighboring systems with high bills significantly correlate with higher water bills. Though we find that water systems with high levels of poverty tend to have higher water bills, our results also suggest that local systems that serve populations with higher levels of income inequality and higher proportions of non-White population tend to have lower water bills. These findings point to future research and data needs to better inform federal, state and local water affordability policy and underline the importance of examining and addressing water affordability at local scales.