In this presentation, Dr. Ying will present some of the key geochemical processes that cause arsenic and manganese to enter groundwater and then move into an analysis of who is disproportionately accessing metals-contaminated drinking water in CA. The results show that many domestic (private) well communities are accessing manganese contaminated water and that many of those communities are characterized as economically disadvantaged. Secondly, they show that even communities accessing treated, public water (community water systems) are not all being served safe drinking water, with smaller water systems having the most exceedances of health-based concentration limits. The aim of this presentation is to provide an overview of some of The Dirty Lab’s multi-scale research on water quality and hope that you might find ways to collaborate with us!