NPDES Wastewater Permitting

The NPDES Section of the Iowa Department of Natural Resources issues discharge permits under delegation of a federal program known as the NPDES (National Pollutant Discharge Elimination System) permit program.  The NPDES program regulates the direct discharge of wastewater to surface waters.  The authority to issue NPDES permits rests either with a state or with the U.S. Environmental Protection Agency (EPA).


NPDES Program
+ NPDES Program Basics

The NPDES Section of the Iowa Department of Natural Resources issues discharge or operation permits under delegation of the federal program known as the NPDES (National Pollutant Discharge Elimination System) permit program.  The NPDES program is a federal program that regulates the direct discharge of wastewater to surface waters.  The authority to issue NPDES permits in a given state rests either with the state's environmental agency or with the U.S. Environmental Protection Agency (EPA).  States can gain approval to administer the NPDES program by demonstrating that their state program meets all federal requirements.  Iowa was delegated authority to administer the NPDES program by the EPA in 1978.

Under Iowa's NPDES program, all facilities that discharge pollutants from any point source into waters of the United States or waters of the state are required to obtain an NPDES or operation permit.  The permits require compliance with all federal standards and may require additional controls based on local conditions.

The term pollutant is defined very broadly and includes any type of industrial, municipal, and agricultural waste discharged into water.  Pollutants can enter waters from a variety of pathways including agricultural, domestic, and industrial sources.  For regulatory purposes, these sources are generally categorized as either point sources or non-point sources.  Typical point source discharges include discharges from publicly owned treatment works (POTWs), discharges from industrial facilities, and discharges associated with urban runoff.  While provisions of the NPDES Program do address certain specific types of agricultural activities, the majority of agricultural facilities are defined as non-point sources and are exempt from NPDES regulation.

Pollutant contributions may come from both direct and indirect sources.  Direct sources discharge wastewater directly into the receiving water body, whereas indirect sources discharge wastewater to a POTW, which in turn discharges into the receiving waterbody.

Because POTWs are direct dischargers, they must obtain and comply with a NPDES permit.  If the concentration of pollutants leaving the POTW is too high, or if the POTW discharges endanger public health or the environment, the facility violates its permit and can be fined and/or forced to upgrade its operation.  A POTW may have trouble meeting its NPDES permit conditions if the amounts of pollutants in the wastewater flowing into the treatment plant (the influent wastewater) are too high.  One way to reduce the amounts of pollutants in the influent wastewater is to require pretreatment.  Thus, the conditions of a POTW's discharge permit might dictate the need for pretreatment.

Industries that are direct dischargers to surface waters must also obtain and comply with a NPDES permit.  Industries that are not direct dischargers, but who discharge wastewater to a municipal sewer system, may be required to have a treatment agreement.  The NPDES Section reviews treatment agreements for conformance to federal and state pretreatment requirements.  Some larger cities have accepted responsibility for administering local pretreatment programs that regulate industrial discharges in their community.

To read more about wastewater, please view the following article from the Iowa Conservationist: Down the Drain: What Happens to Our Wastewater?  (*.pdf file)

+ Types of NPDES Permits
+ Major Components of a Permit
NPDES Databases - Individual and General Permits
+ Individual Permits - WWPIE
+ General Permits - Online Storm Water Database
+ Other Individual or General Permits
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Proposed General Permits for Hydrostatic Testing and Dewatering:

The NPDES Section has proposed two new general permits. General Permit #8 will be for Hydrostatic Testing, Tank Ballasting, and Water Lines and General Permit #9 will be for Dewatering Activities and Residential Geothermal Discharges. For more information and drafts of the general permits, please refer to the NPDES General Permit #8 and the NPDES General Permit #9 webpages.


General Permit #6 Renewal:

The NPDES General Permit for Well Construction and Well Service Discharges (also known as GP6) will expire on February 28, 2020. Iowa DNR proposes to initiate rulemaking to renew the permit for a third 5 year term.

A stakeholder meeting regarding the renewal of GP6 is scheduled for 3:00 PM on Thursday, May 24, 2018 at the Wallace State Office Building, 502 E. 9th Street, Des Moines, IA 50319.

For more information on the stakeholder meeting and the submission of written comments on the proposed general permit, please see the General Permit #6 webpage.


Disadvantaged Communities:

For more information on how a community or entity may qualify as disadvantaged, please see the Rural Community Sewers page.