The environmental justice implications of retirement age assumptions in domestic well vulnerability analyses

Abstract Due to the compounding threats of over extraction and climate change, groundwater resources are under pressure globally. This can lead to groundwater levels dropping and domestic wells going dry, with significant consequences for public health and wellbeing. Domestic well vulnerability analyses are an important tool that can help water managers prevent and mitigate such impacts. However, information gaps related to well activity status introduce significant uncertainties into these models. In this technical note, we create a hypothetical groundwater surface for California’s Central Valley based on locally developed sustainable groundwater management plans and compare both the degree of domestic well dewatering and the distribution of dewatering across the population under a range of different retirement age assumptions. Our sensitivity analysis demonstrates that not only do domestic well retirement assumptions influence the expected number of impacted wells, but also who is forecasted to be impacted: Older retirement age assumptions predict larger proportions of well impacts with higher instances of dewatering in census block groups with larger populations of people of color and low-income people of color specifically. Thus, the potential consequence of underestimating well age in the study area is to perpetuate environmental injustice. To avoid doing so, wherever possible data on well activity status should be collected and utilized. Where data is not available, researchers and water managers should use best practices including employing uncertainty analysis and environmental justice assessments.