Background: Nitrate contamination in groundwater disproportionately impacts agricultural Latino communities, creating a significant hazard for Latinos that rely on private wells. Private well users must conduct water testing and other well stewardship behaviors to ensure their well water is safe to drink. This study sought to identify the barriers and facilitators of private well water testing in rural, agricultural Latino communities.Methods: We conducted four focus groups with private well users, two in Spanish and two in English.We recruited 37 participants from the Lower Yakima Valley, Washington State, a rural, agricultural community with a large Latino population and elevated nitrate concentrations in groundwater. A semi-structured interview guide was developed to capture testing barriers and facilitators guided by the Risk, Attitudes, Norms, Ability, and Self-Regulation (RANAS) model. Inductive thematic analysis was conducted by two coders to identify common themes.Results: Themes emerged around barriers and facilitators to well stewardship behaviors, including well testing, treatment, and maintenance. Barriers included limited actionable information, economic limitations, lack of technical support, and challenges related to landlords and neighbors. Facilitators of well stewardship included concerns about well water contamination, knowledge of agricultural sources of contamination, do-it-yourself (DIY) home repair experience, and responsibility to protect family.Conclusions: Well stewardship programs in rural, agricultural Latino communities may want to prioritize communication that provides actionable information on well water testing, treatment, and maintenance and emphasizes the responsibility to protect family in its messaging. Additionally, programs that provide financial and technical assistance and well maintenance education that builds on DIY home repair experience may be effective in these communities.US Geological Survey (USGS) in 48 states, 23% of domestic wells in the US contained one or more contaminants at a concentration exceeding a human health standard [2]. Nitrate is the most common anthropogenic contaminant in private wells [2], originating from synthetic fertilizers, fossil fuel combustion, animal waste, and wastewater [3]. The maximum contaminant level for nitrate in regulated drinking water sources is 10 mg/L NO 3 -N [4]. Consuming water above this concentration may lead to developmental effects, gastrointestinal cancer, and methemoglobinemia, which can be fatal in infants if not treated [5].Nitrate contamination in drinking water supplies disproportionately impacts Latino communities [6,7].Public water systems in the top quartile of percent Latino residents served are nearly three times more likely to exceed 5 mg/L of nitrate than public water systems in the bottom quartile [7]. These disparities may occur because agriculture is the largest input of nitrogen in US water resources [3], and 83% of farm workers are Latino [8]. Public water systems with groundwater sources have higher ni...