Water quality inequality: a non-targeted hotspot analysis for ambient water quality injustices

Water is an essential human resource tied to many social and environmental needs and values. Although water has been a focal point of many environmental justice studies, ambient water quality (i.e. water quality before the tap) has been overlooked. This oversight has resulted in only a partial understanding of how water quality may correlate with communities facing environmental justice issues. We analysed data from the US Environmental Protection Agency STOrage and Retrieval (STORET) database and the 2010 US Census to identify poor ambient water quality within non-white and low-income communities across the Southeastern USA using hotspot analysis, ordinary least squares, and geographically weighted regressions. Our analyses indicate that non-white and low-income communities are significantly impacted by copper, lead, and mercury contamination. Race correlates more strongly with poor ambient water quality than do community income levels. The results suggest our approach and analyses are effective for identifying potential environmental justice issues across large spatial scales using a top-down rather than a bottom-up approach.