TMDLs are a requirement of the federal Clean Water Act (CWA), which was passed in the early 70s to provide direction for maintaining and restoring the quality of the nations waters. At the time, Mississippi, as well as the rest of the country, was focused on addressing the most severe pollution problems which were caused point sources and unsewerted communities where improperly treated wastewater was severely impacting the nations surface waters. Addressing those problems took priority over development of TMDLs and consequently resolved many of the nations most severe water quality problems.
In 1997, the Sierra Club sued the Environmental Protection Agency for not developing TMDLs in most states, including Mississippi. EPA settled the lawsuit by agreeing to do all of the TMDLs listed in the 1996 Section 303(d) list within 10 years. Although not a party to the law suit, MDEQ has established a goal to develop TMDLs for Mississippi in accordance with the court order.