nation of pollution” and to “encourage the enactment of improved and … uniform State laws relating to the prevention, reduction, and elimination of pollution” (Section 103). Moreover, the EPA has clear statutory authority to (1) take over from states the setting of water quality standards and TMDLs when state efforts do not comply with the Clean Water Act’s requirements; (2) convene, at a state’s request, interstate nonpoint source management conferences; (3) convene multistate conferences to develop comprehensive water quality management plans to protect National Estuaries; (4) hold hearings to address interstate pollution caused by federally licensed or permitted activities, including water-based activities permitted by the U.S. Army Corps of Engineers; and (5) veto state NPDES permits and take over the permitting process to ensure that interstate pollution from upstream or cross-stream point sources is adequately addressed. As a result, the EPA has the authority to establish TMDLs with interstate effects and, at least for point sources, regulatory requirements designed to achieve those TMDLs, including water quality criteria set at levels designed to address interstate water quality problems. The Clean Water Act also encourages the EPA to stimulate and support interstate cooperation to address larger-scale water quality problems. The act provides the EPA with multiple authorities that would allow it to assume a stronger leadership role in addressing Mississippi River and northern Gulf of Mexico water quality.