On August 1, 2014, routine testing at the Collins Park Water Treatment Plant in Lucas County, Ohio, revealed microcystin toxin levels in drinking water had reached 3.19 μg/L, surpassing the Ohio Environmental Protection Agency (EPA) drinking water advisory threshold of 1.0 μg/L. Microcystin is a hepatoxin released by cyanobacteria in certain harmful algal blooms. Exposure to microcystin has been associated with gastrointestinal and hepatic illness in both humans and animals (1-3). On August 2, a do-not-drink advisory was issued, warning community members not to drink, boil, or use the water for cooking or brushing teeth. Public health officials used traditional and social media outlets to disseminate public health messages to affected communities. On August 4, 2014, the advisory was lifted after multiple water samples confirmed microcystin toxin levels had dropped below the advisory threshold. To assess communication strategies, water exposure, and household needs, the Ohio Department of Health (ODH) and Toledo-Lucas County Health Department (TLCHD) conducted a Community Assessment for Public Health Emergency Response (CASPER) in Lucas County. Most households (88.1%) reported hearing about the advisory the morning it was issued, but 11% reported drinking and 21% reported brushing teeth with municipal water during the advisory. Household members reported physical (16%) and mental (10%) health concerns that they believed were related to the advisory and activity disruptions including temporarily staying outside of the home (6%) during the advisory and continued use of alternative water sources after the advisory was lifted (82%). During a do-not-drink advisory, governmental agencies and community partners need to engage in joint prevention and response efforts to decrease water exposure and prevent activity disruptions.