Some African-American communities in the U.S. South are excluded from nearby municipal water and sewer services and therefore rely on private wells and septic systems. These “underbounded” communities are disproportionately exposed to water contaminants and face elevated risks for poor health outcomes. Outreach efforts encouraging proper well testing and maintenance are needed to protect health in these communities. To identify knowledge gaps and misconceptions that such outreach programs should target, we conducted semistructured interviews with 18 residents of such communities in Wake County, North Carolina. Only one interviewee conducted annual well testing as recommended by the county health department. Interview results suggest that testing is inhibited by lack of awareness of well maintenance guidelines, overreliance on sensory information, poor understanding of exposure pathways, and cost. Links between private septic systems, well water contamination, and health are poorly understood, hindering proper septic maintenance. These findings highlight the need for risk communication materials targeting at-risk communities.