National Pollutant Discharge Elimination System (NPDES)
The NPDES permit limits the discharge of potential pollutants to protect the waters that receive them. The health of a water body is measured by its attainment of designated uses. If potential pollutants in a NPDES discharge are reduced to levels that allow receiving waters to meet applicable designated uses then, in effect, the pollutant discharge has been eliminated.
For example, a freshwater stream could have designated uses of "protection of aquatic life" and (human) "drinking water." A chloride discharge to that stream is a pollutant since it could adversely affect freshwater organisms and drinking water quality. The same chloride discharge is likely not a pollutant when discharged into a saltwater body. Saltwater species are accustomed to chlorides and the water body is not used for human drinking water.
NPDES programs through the Surface Water Discharge Section
Other NPDES permit coverage options in Delaware
Return to Surface Water Discharges Section