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Who Must Apply for a NPDES Stormwater Permit

- ATTENTION -
All stormwater general permit applications (NOIs) must be accompanied by the following fees:
1 year - $175.00     3 years - $350.00     4 years - $525.00     5 years - $700.00

Stormwater general permit applications (NOIs) may be submitted online at:
Online Stormwater General Permit Database


Who Must Apply for a Stormwater Discharge Permit?

There are three general classes of activities that must be covered by stormwater permits. These are:

  1. Construction activity that disturbs one or more acres or which is part of a larger project that disturbs one or more acres in total.
  2. Certain types of industrial or commercial activities.
  3. Many city storm sewer systems in larger communities or those near larger communities. 

Please note, any discharge from a facility or construction site that may temporarily degrade an Outstanding National Resource Water or Outstanding State Resource Water is required to be permitted by an individual NPDES permit, as stipulated in 567 Chapter 64 of the Iowa Administrative Code and in the Iowa Antidegradation Implementation Procedure. General permit coverage is not available for these discharges. The list of these waters is located in Appendix B of the Antidegradation Implementation Procedure


Construction activity that disturbs one or more acres:

Construction activity that disturbs one or more acres must be covered by a stormwater permit before any soil is disturbed at the site. Construction activities are covered under General Permit No. 2 (GP #2). The following guidelines apply to coverage under GP #2:

  • Permit coverage must be continued until all building is completed and the ground is completely stabilized with a permanent, perennial, vegetative cover.
  • Building is not complete until all houses and buildings are constructed and the ground has been stabilized. Before this is achieved, permit coverage must be maintained.
  • If only one year of permit coverage was initially purchased and, after one year, the ground is not completely stabilized, permit coverage must be renewed.
  • For residential and commercial developments, permit coverage must be maintained after initial grading and street construction.

To apply for coverage under GP #2, use the Online Stormwater General Permit Database

Paper application forms (Notices of Intent) and information may also be found on the Permits, Guidance, and Forms webpage.


Industrial and commercial activities (Stormwater Discharge Associated with Industrial Activity):

Industrial and commercial activities that are classified as having "stormwater discharge associated with industrial activity" are required to obtain permit coverage. EPA's definition of "stormwater discharge associated with industrial activity" from 40 CFR 122.26 and in Iowa Administrative Code 567 IAC Chapter 60 can be found at this link: Definition - Stormwater Discharge.

Most industrial activities are covered under General Permit No. 1 (GP #1) or by individual permits.

Facilities such as asphalt plants, concrete batch plants, quarries, sand and gravel pits, and rock crushers are covered under General Permit No. 3 (GP #3).

A summary of the types of industrial facilities and activities subject to the regulations are provided in Table 1, "Facilities or Activities Defined as Industrial Activities Subject to Stormwater Discharge Application Requirements".

To apply for coverage under GP #1 or GP #3, use the Online Stormwater General Permit Database.

Paper application forms (Notices of Intent) and information may also be found on the Permits, Guidance, and Forms webpage.


No Exposure Exemption:

If all industrial materials and activities at your facility are protected by a storm resistant shelter that prevents exposure to rain, snow, snowmelt, and/or runoff, you may not need a stormwater permit. Industrial materials or activities include, but are not limited to,

  • material handling equipment or activities (including storage, loading and unloading, transportation, or conveyance of raw material, intermediate product, final product, or waste product);
  • industrial machinery;
  • raw materials;
  • intermediate products;
  • by-products;
  • final products; or
  • waste products.

To qualify for a no exposure exemption, complete and submit the No Exposure Certification Form. A No-Exposure Certification must be provided for each qualifying facility.

The no exposure exemption is ONLY available on a facility-wide basis; it is not for individual outfalls. If any industrial activities or materials at your facility are exposed to precipitation, the facility is not eligible for the exemption.


Municipal Separate Storm Sewer System (MS4) NPDES Permits:

Many cities and universities in Iowa are required to have individual NPDES permits for their Municipal Separate Storm Sewer Systems (MS4s). The determination of which cities and universities are required to obtain individual MS4 permits involves a combination of population, proximity to large, urbanized areas, and the water quality of receiving streams. MS4 permits require permittees to implement measures to:

  • reduce pollutants in stormwater from illicit discharges and construction sites,
  • provide public education,
  • allow for public participation,
  • minimize pollutants from municipal operations, and
  • address post-construction runoff. 

Please refer to the MS4 Permittees webpage (linked above) for a list of MS4 permit holders in Iowa.


Application Deadlines for New Stormwater Discharges:

For coverage under a general stormwater discharge permit, a complete Notice of Intent (NOI) must be submitted to DNR and an authorization approved and issued by the Department prior to the start of operations or soil disturbing activities, as specified in 567-64.3(4)"b" of the Iowa Administrative Code.

For an individual NPDES permit, an application must be submitted 180 days prior to the start of operation.

Please see the Application Options & Fees page for more information.