The National Pollutant Discharge Elimination System (NPDES) regulates point sources that discharge pollutants into the state’s surface water bodies. It helps ensure that the state’s water bodies can meet their designated uses, such as providing drinking water, being safe for swimming or fishing, or supporting aquatic life.
A NPDES permit limits the discharge of 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.
Currently, only three surface water bodies are used for drinking water purposes in Delaware (White Clay Creek, Red Clay Creek and the Brandywine River). There are no Delaware-permitted NPDES wastewater operations that discharge in the upstream segments.
The NPDES permit program was created by the Clean Water Act, in 1972. Management of the program, with the exception of pre-treatment and federal facilities, is delegated to DNREC under Section 402 of the Act, and Delaware State Law (7 Del. Code, Chapter 60).
NPDES permits are typically issued to commercial or industrial facilities, or to municipalities, for the discharge of pollutants to surface waters.
There are two types of NPDES permits, individual and general.
General permits are issued for a given state-wide activity such as the discharge of storm water associated with industrial activities.
Individual permits are permits developed and issued on a case-by-case basis for activities not covered by general permits.
Division of Water staff provide compliance assistance to new permittees or those permittees that have questions about parts of their permit.
Division staff review data submitted by permittees, conduct their own surveillance and monitoring program, and provide oversight to ensure facilities maintain compliance with their permits
If a facility is unable to maintain compliance with their permit, DNREC has various enforcement tools, ranging from a verbal warning to an Administrative Order with penalty, that can be used to document the violation, require a return to compliance, and penalize the permittees as necessary.