Environmental health literacy (EHL) is a new term that encompasses environmental health knowledge, awareness, skills, and self-efficacy, as well as community action. An interdisciplinary team of university scientists collaborated with local organisations to develop and implement EHL trainings in four communities, with a particular focus on rainwater gathering and water contamination. Participants' prior knowledge of environmental health risks and personal experiences were used to co-create training content during these participatory trainings. All four trainings (n=53) were subjected to a mixed methods evaluation that included prepost participant surveys. Participants who did not have a strong foundation in environmental science prior to training showed a significant gain in understanding thereafter.