The Clean Water Act requires all municipalities, townships and unincorporated areas of DuPage County to comply with National Pollutant Discharge Elimination System (NPDES) permitting to restore and protect the water quality of the Waters of the State from pollutants associated with stormwater runoff. Stormwater Management offers all municipalities and townships within the County the opportunity to utilize the County’s water quality programs to comply with the requirements of NPDES, saving taxpayers millions of dollars based on economies of scale. The Clean Water Act also requires a Total Maximum Daily Load (TMDL) be developed for each pollutant of an impaired water body. It determines the load or quantity of any given pollutant allowed in a particular water body. A TMDL must consider all potential sources of pollutants, both point and non-point, while taking into account a margin of safety and the effects of seasonal variation. Click here for our NPDES.