This report from the National Research Council (NRC) Committee on Clean Water Act Implementation Across the Mississippi River Basin was sponsored by the U.S. Environmental Protection Agency and it offers strategic advice and priorities for addressing Mississippi River basin (MRB) and northern Gulf of Mexico (NGOM) water quality management and improvements (see Box 1-1 for the committee's full statement of task). In some areas, this report refers to and builds upon previous NRC studies on the Clean Water Act and Mississippi River basin and NGOM water quality (NRC, 2008 and 2009). Those reports note the limited authority of the EPA under the Clean Water Act to achieve the goals stated by the Task Force and the EPA Science Advisory Board. Although there is considerable uncertainty as to whether national water quality goals can be fully realized without some fundamental changes to the CWA, there is general agreement that significant progress can be made under existing statutory authority and budgetary processes. More details of the findings and recommendations from those reports are listed in the main body of this report (especially see Box 1-2 for a listing of key findings and recommendations from the reports, which provide detailed advice to EPA, USDA and others regarding water quality monitoring and evaluation, nutrient criteria development, and nutrient control activities).