This research aims to assess the potential for drinking water contamination in Los Angeles County, California, by examining the proximity of supply wells to oil and gas wells. It also seeks to analyze the associated risks in relation to race/ethnicity and structural racism. The study identifies at-risk community water systems (CWSs) based on the proximity of supply wells to oil or gas wells, evaluates the demographics of the populations served by each CWS, assesses historical redlining using 1930s maps, and examines residential segregation. The findings reveal that a significant portion of LA County CWSs, serving over 7 million residents, have supply wells within 1 kilometer of an oil or gas well. Moreover, the study indicates that higher contamination risk is associated with larger percentages of Hispanic, Black, and Asian/Pacific Islander residents, as well as a greater degree of historical redlining and residential segregation, highlighting the increased vulnerability of people of color to drinking water contamination from oil development in LA County. Find here JPB Fellow Lara Cushing’s article.