What Does Total Maximum Daily Loads (TMDL) Mean?
Total maximum daily load (TMDL) is a calculation of the maximum amount of pollutant that a waterway can contain to stay within water quality standards. Sources of pollutants are categorized as either point or non-point. Point sources include all sources of pollutant that are subject to the National Pollutant Discharge Elimination System (NPDES). These include wastewater treatment facilities, and stormwater discharges. Non-point sources include all remaining sources of pollutant, including natural background sources.