There are three general classes of activities that must be covered by storm water 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. Several types of industrial or commercial activity.
   
   
3. Many city storm sewer systems in larger communities or those near larger communities.

Construction activity that disturbs one or more acres must be covered by a storm water permit before any soil is disturbed at the site. The permit coverage must be continued until all building is completed and the ground is completely stabilized with a permanent, perennial, vegetative cover. 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. 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. Application forms and information may be found here. Construction activities are covered under General Permit no. 2.

Industrial and commercial activities that are classified as having "storm water discharge associated with industrial activity" are required to obtain permit coverage. As found in the Code of Federal Regulations, 40 CFR 122.26, and the Iowa Administrative Code, 567-60, the definition can be found here. Application forms and information may also be found on our website. Most industrial activities are covered under General Permit no. 1 or 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.

If all industrial materials and activities are protected by a storm resistant shelter to prevent exposure to rain, snow, snowmelt, and/or runoff you may not need a storm water permit. Industrial materials or activities include, but are not limited to, material handling equipment or activities, industrial machinery, raw materials, intermediate products, by-products, final products, or waste products. Material handling activities include the storage, loading and unloading, transportation, or conveyance of any raw material, intermediate product, final product or waste product. If you think you may qualify for a no-exposure exemption, complete and return to the Department the "No-Exposure Certification Form."

Many cities and universities in Iowa are required to have permits for their Municipal Separate Storm Sewer Systems (MS4s). The determination of which cities and universities are required to obtain MS4 permits involves a combination of population, proximity to large, urbanized areas and water quality of receiving streams. These permits require municipalities to implement measures to reduce pollutants in storm water from illicit discharges and construction sites, to provide public education and allow public participation, to minimize pollutants from municipal operations and to address post-construction runoff. The Department is currently issuing permits to these municipalities.

EPA's definition of "storm water discharge associated with industrial activity" is contained in Appendix A. A summary of the types of industrial facilities and industrial activities which are subject to the regulations are provided in Table 1.


Application Deadlines for new storm water discharges:

For coverage under a general storm water discharge permit - a properly completed Notice of Intent must be submitted to the IDNR 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 - 180 days prior to the start of operation

• Appendix A: Definition of "Storm Water Discharge Associated with Industrial Activity" (40 CFR 122.26(b)(14))
  
  
• Table 1: Facilities or Activities Defined as "Industrial Activities" Subject to the Storm Water Discharge Application Requirements