What is a “disproportionately high or adverse effect”?

Whether an adverse effect is “disproportionately high” on minority and low-income populations depends on whether that effect is (1) predominantly borne by an EJ population, or (2) will be suffered by the EJ population and is appreciably more severe or greater in magnitude than the adverse effect that will be suffered by the non-EJ population. It is important to note that determinations of disproportionately high and adverse effects take into consideration the mitigation and enhancement measures that are planned for the proposed action.