Appalachian Kentuckians in Martin and Letcher Counties are grappling with a health-threatening drinking water crisis arising from exposures to disinfection by-products (DBPs). DBPs include trihalomethanes (THMs), haloacetic acids (HAAs), chlorate, and other compounds that have been associated with a variety of adverse health effects, including increased risk of bladder cancer and cardiovascular birth defects. This study implements a multi-stakeholder, multi-method approach to improve understanding of, characterize spatial and temporal variations in, and reduce exposure to DBPs in these Appalachian Kentucky counties.