Our analysis found more frequent detections of unregulated industrial contaminants in public water systems serving higher proportions of Hispanic and non-Hispanic Black residents. These associations persisted even after taking other factors into account (e.g., SES, proximity to pollution sources). Although some of the associations between race, ethnicity, and unregulated contaminants can be explained by disproportionate siting of industrial facilities, our analysis suggests that other factors contribute to disparities in exposures to unregulated drinking water contaminants. Our analysis indicates that drinking water disparities can be overlooked and underestimated when research narrowly focuses on regulated chemicals in drinking water. Elucidating other vulnerability factors and mechanisms by which demographics influence drinking water can promote actions to implement the SDWA more effectively and equitably.