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Impaired Waters and TMDLs

Water Quality-based Approach of the Clean Water Act

Water quality restoration and protection in the United States is based on assessing waters and taking actions to restore or protect them. Goals are set, water samples are taken, data is evaluated, calculations made and measures are developed to return the water to, or maintain, its original health.

The diagram presents the water quality-based approach of the Clean Water Act. It highlights the steps that are part of EPA's 303(d) Program.