While the literature on the water-energy nexus tends to focus on scarcity and security, scientific research is revealing increasing concerns with the impact of energy production on water quality. This chapter explores the politics of energy and water quality, with a focus on water contamination associated with coal and shale gas development. It presents evidence of the effects of fossil fuel exploration and production on water quality, noting the life cycle water quality impacts of the coal industry and emerging work on the effects of unconventional shale gas and tight oil associated with hydraulic fracturing. While the science is drawn primarily from the United States, the chapter then considers the global implications of these findings for policy design. It argues that current regulatory approaches are mismatched with the environmental risks and calls instead for a holistic approach to policy design and management that brings together the energy and water sectors.