Archive geospatial download files for pre-2015 ATTAINS data, including: Pre-2015 303(d) Listed Impaired Waters Reach Indexed Dataset Archive, Pre-2015 305(b) Waters As Assessed Reach Indexed Dataset Archive, 2002 Impaired Waters Baseline Reach Indexed Dataset Archive, Watershed Boundaries for the 2002 Impaired Waters Baseline, and Pre-2015 Impaired Waters with TMDLs Reach Indexed Dataset Archive. The Total Maximum Daily Load (TMDL) Tracking System contained information on waters that are Not Supporting their designated uses. These waters were listed by the state as impaired under Section 303(d) of the Clean Water Act. The status of TMDLs were also tracked. TMDLs are pollution control measures that reduce the discharge of pollutants into impaired waters. A TMDL or Total Maximum Daily Load is a calculation of the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, and an allocation of that amount to the pollutant's sources. Under Section 305(b) of the CWA, the states, territories, and other jurisdictions of the United States are required to submit reports on the quality of their waters to the U.S. Environmental Protection Agency (EPA) every 2 years.