On or Under Act This bill requires the federal government to acquire all current existing mineral rights, including lease interests, that exist in the subsurface of federally owned sites on the National Priorities List (the list of sites of national priority among the known releases or threatened releases of hazardous substances, pollutants, or contaminants). The bill also requires the Environmental Protection Agency to prohibit any drilling, excavation, or other disturbance of the federally owned subsurface beneath a site listed on the National Priorities List other than for the purposes of site cleanup.