v waterbodies that lie wholly within their respective boundaries. As explained in this chapter, this has contributed to a situation in which the Mississippi River is to a large degree an “orphan” from a water quality monitoring and assessment perspective.

This chapter examines administrative issues and challenges regarding implementation of the Clean Water Act along the interstate Mississippi River. It begins with discussion of the progress in controlling point source pollution and concludes with a focus on efforts to address the more complicated nonpoint source challenges. It discusses the respective roles and responsibilities of federal and state agencies in implementing the Clean Water Act (CWA) along the Mississippi River; the fragmented jurisdictional picture that underlies and affects CWA implementation; the state of water quality assessment along the 10-state Mississippi River corridor; and the development of TMDLs and nutrient criteria for the river.

Water quality protection and improvement programs of many of the states bordering the Mississippi River started well before the increasing national environmental consciousness that began in the 1950s and 1960s and before passage of the original Clean Water Act. As explained in Chapter 3, after the Clean Water Act’s passage in 1972, the National Pollutant Discharge Elimination System (NPDES) became an important mechanism for reducing Mississippi River point source pollution. Table 4-1 lists the agencies that, in large part, currently administer the NPDES and water quality standard programs for each of the Mississippi River mainstem states.

Along the Mississippi River, NPDES permits have been issued to thousands of industrial, municipal, and other point source dischargers, both large and small. Table 4-2 identifies the “major” Mississippi River dischargers that currently have NPDES permits. Although the Environmental Protection Agency (EPA) Permit Compliance System (PCS) database gives only a fragmentary and not completely up-to-date picture of the status of the permit program, Table 4-2 nevertheless provides an indication of the extent of major point source discharges to the Mississippi River.

NPDES permits impose “best-technology” requirements on point sources and, therefore, constitute one of the principal mechanisms within the Clean Water Act to reduce pollutant discharges into “navigable waters,” which are defined very broadly. Although the NPDES program resulted in substantial reduction of pollutant inputs to the Mississippi River (especially sewage-related pollutants as documented below), limited data