Although the EPA has taken the most systematic approach to scrutinizing the flow of money, it is not the only entity to do so. Attorney General Jeff Sessions has vowed to withhold Justice Department grants from "sanctuary cities" that refuse to hand over arrested immigrants who cannot prove they are in the country legally. The Interior Department, which is conducting a review of its grants, last month canceled a $100,000 National Academies of Sciences, Engineering and Medicine study aimed at evaluating the impact of surface mining on nearby communities.