Environmental justice studies tend to deemphasize political economic processes, social relations between various social groups, scale and the social constructions of environmental issues which hide environmental injustice. Political ecology, in contrast, emphasizes issues of social relations, scale, political economy, marginalization, and social constructionism, which are useful for identifying the environmental injustice often hidden by both developmentalist and mainstream environmentalist approaches to environmental conflict. Using a political ecology framework, this research uncovers the environmental injustice hidden in conflicts over coal plant installation and expansion on Yeongheung Island, South Korea. Methods include analysis of public reports and statements and qualitative interviews with 20 local residents. Even though the residents live in poverty and suffer the effects of coal-dust, noise from transmission towers, and tidelands destruction, environmental justice has little presence in environmental debates and decision-making. Instead, these derive from dominant social relations among developers, governments and environmentalists, with the local residents excluded, marginalized and disempowered from the discourses. At the scale of national and global capitalism, localized environmental injustice is a consequential result of global and national scale of political economy. In addition, the environmental injustice tends to be hidden by social constructions of coal energy, nature and environment and scale, which are manipulated by developers, environmentalists and governments. Political ecology provides the theoretical lenses to see how money floats upward and pollution sinks downward as environmental injustice is produced and hidden.