Effective March 10, 2003, all construction projects that disturb 1 acre or more are required to a stormwater permit. Storm Water Discharge requirements are mandated by Iowa Code in Chapter 455B.105 and 455B.173.  Further guidance is provided in Iowa Administrative Code 567 Chapter 64.


A Storm Water Permit requires specific actions intended to reduce and/or eliminate the problems associated with runoff, soil erosion, and siltation.  To comply with this environmental regulation, the DOT has developed the following procedure:

n  Projects or groups of projects (such as corridor projects) which disturb 0.4 hectare (1 acre) or more are identified by the Office of Design.  It is Office of Design's (or a consultant's) responsibility to prepare a Pollution Prevention Plan (PPP), the Notice of Intent (NOI), and newspaper notice for these projects.

n  When projects are turned in, the Office of Contracts tabulates projects with PPPs.  The Office of Design sends NOIs and newspaper notice to the Office of Construction and Materials.

n  The Office of Construction and Materials forwards required notice to appropriate newspaper for publication.  Once publication verification is returned, the Office of Construction and Materials assembles all parts for NOIs and forwards copies to Iowa DNR.

n  Upon receipt of the permit authorization from the DNR, the project engineer administrating a particular project is notified by the Office of Construction and Materials that a Storm Water Permit is in place.  (The contractor may begin work any time after that notification.)


The project engineer shall check to assure that projects requiring a Storm Water Permit have a Pollution Prevention Plan (PPP).  Along with a PPP there "should" be bid items for pollution control items such as silt fence, stabilizing crops, ditch checks, etc.  As always, it is important to check preliminary plans whenever possible to be sure all needed contract items have been included.  Obviously, if a contract is let without erosion or sediment control items, the project engineer will have to add those items.



NOIs are Iowa DOT's official notification to Iowa DNR that there is a project, located at "xxxxxxxxxxxxxxxxx," and the project will be disturbing soil. Once Iowa DNR receives and processes the NOI, they return a Discharge Authorization Number (DAN) to the Office of Construction and Materials.


DANs are issued by Iowa DNR for 1, 3, 4, or 5 years (depending on what was requested on the NOI), after which they must be either renewed or discontinued.  When the Office of Construction and Materials receives a notice of renewal, the project engineer is contacted to inquire if a permit should be renewed.  If renewal is requested, the Office of Construction and Materials will process and pay the renewal fee.  Before requesting renewal, answer:

n  Is permanent seeding 70% established for the entire project?  If so, the project should have (or needs to have) a Notice of Discontinuation (NOD) prepared.  The project engineer is required to complete a NOD and submit it to the Office of Construction and Materials  (Note:  Submitting NOD to Office of Construction and Materials is required for projects where DOT is the Contracting Authority.  Cities or counties who are Contracting Authority should send NOD to the DNR, not the Office of Construction and Materials).  If a project is completed "and" permanent seeding is 70% established, DO NOT wait to process a NOD.  Prepare the NOD as part of your ongoing project paperwork.  (A blank NOD - Form 830216 is provided in Appendix 10‑4.  This form is used for DOT-administered projects.


n  Is the project incomplete, or is the permanent seeding less than 70% established?  If so, the DAN most likely will need to be renewed.  (Be sure to make a real effort to evaluate the permanent seeding issue.  Every DAN that is renewed also requires a renewal fee.)


n  The DNR has interpreted that “70% established” is considered within a random square area, not that 70% of the project area is fully seeded and 30% is bare.




General Permit #1

General Permit #1 is the Storm Water Discharge Permit required for industrial activities.


General Permit #2

General Permit #2 is the Storm Water Discharge Permit required for construction projects which result in disturbance of 1 acre or more.


General Permit #3

General Permit #3 is the Storm Water Discharge Permit required for asphalt plants, concrete batch plants, rock crushing plants, construction sand and gravel facilities. This permit applies to portable and stationary plants. The 1 acre requirement does not apply to plant sites. 


If a site is in an Outstanding Iowa Waters (OIW) watershed, the project cannot obtain coverage under a general permit. Rather, an individual permit is obtained from the Iowa DNR. Individual permits require different application forms and a longer application period than projects covered by a general permit.  A map of OIW watersheds and a list of OIWs is provided in “FAQs for Environmental Considerations, Clearances and Permits” on the Office of Construction and Materials’ website. 



n  Contractors will be responsible to obtain Storm Water Permits for their activities on or off of the project. For example: if a contractor sets a portable plant “on” or “off” Iowa DOT ROW, the contractor is responsible for obtaining coverage for the site under Permit #3.  The contractor is also responsible to provide proof of coverage to the project engineer for plants on Iowa DOT ROW. Project engineers should not allow that site to provide material to a project until there is documented proof of coverage.


n  All contractors and subcontractors who deal with or have an impact on storm water pollution issues shall sign a co-permittee certification prior to conducting any land disturbing work on the project. Prime contractors are required to submit the signed certificate with their signed contract to the Office of Contracts. It is the prime contractor’s responsibility to obtain and provide signed certificates for the subcontractors to the project engineer. (A copy of a co-permittee certificate is included in Appendix 10-2). Co-permittee certifications are not required for subcontractors who do not disturb a significant amount of soil or whose operations would not have a potential for discharging a pollutant (i.e. contract survey, material suppliers and traffic control).


n  Inspection of the project’s erosion and sediment control features are required at least once every 7 calendar days. Inspection staff and contractors are to perform joint inspections and document findings on the Storm Water Site Inspection Report (Form 830214). A copy of this form is included in Appendix 10-3. Deficiencies of erosion and sediment control features such as silt fence which is damaged or needs silt removed, washed out mulch, lack of silt fence or mulch shall be reported to the contractor as soon as possible.  The contractor is expected to correct the deficiency or install additional erosion and sediment control features within 3 working days.


n  Project engineers must ensure that erosion and sediment control measures and inspection are maintained by a responsible party during winter shutdown and between projects (i.e. grading/paving/erosion control).


n  There is no longer a maximum exposed area established by the specifications.  However, Article 2602.03, I requires the Contractor to limit earthwork operations in progress to an area commensurate with their capability.  Also, Article 2102.03, K equires the contractor to keep finishing operations current with other construction operations.   Commensurate with the contractor’s capability would mean:


A.   The contractor has current exposed area protected with erosion or sediment control measures.  Minimum measures would include silt fence around the perimeter of the area, ditch checks, and additional silt fence where sediments may leave the project.  This includes all disturbed areas (i.e., borrows, areas within temporary and permanent easements.)


B.   The contractor has demonstrated ability and willingness to keep erosion and sediment control measures current and maintained within existing work areas.


C.  The contractor is considering the time of year before exposing additional areas.  For example: It would not be unreasonable for the Engineer to suspend operations in a situation where it is late in the grading season and the contractor is falling behind in finishing, applying mulch, or temporary seeding.


D.  The contractor has successfully followed their erosion control implementation plan.  The project engineer has not noted storm water violations, and has every reason to believe additional open areas will not over‑extend the contractor's ability to comply with our Storm Water Pollution Permit.


n  Installing and maintaining erosion and sediment control features is the responsibility of the prime contractor. On most projects, the contractor will assign the erosion and sediment control items to a subcontractor. The prime contractor must be prepared to accomplish the required erosion and sediment control work if a subcontractor is not able to perform satisfactorily or timely.



The weather is not favorable to establish temporary seeding or silt fences.  What do we do?

A.   Stabilization:

Regulations say if an area will not have any activity for 21 days; by the 14th day, some form of stabilization will be required.  There is very little latitude in that statement even if it is wet or freezing. 


To be in compliance with storm water regulations, some type of stabilization needs to be done.  For example, incorporating mulch, using Hydro‑Mulch or Soil Binders which are comprised of wood fiber and paper mulch.  Both work, but tend to be expensive knowing it is less than temporary and we will have to ultimately seed.


Best solution is to conduct temporary seeding in a timely manner and not let the contractor get so much open that it cannot be stabilized by seeding.  At the least keep it to a minimum so if one of the other alternates is necessary, costs can be kept to a minimum.


B.   Localized Soil Erosion  (Ditch Check and Silt Fences):

There might be situations where you are unable to properly install silt fence.  In these cases, perimeter and slope sediment control devices (logs, wattles, or filter socks) are a great alternative.  For example:

n  It is wet and muddy; a trencher cannot get in to place silt fence. 


n  The ground is frozen to a point where a trencher will not work.  Winter is coming.  Rather than do nothing, some type of control should be installed so there is protection in place during the spring thaw. 


How are borrows evaluated for Storm Water compliance? 

All project specified borrows are included in the calculation for a Pollution Prevention Plan (PPP).  Plus, these borrows are included in determining compliance with Specification 2602.03


Onsite borrows will be covered under a project’s storm water discharge permit.  Offsite borrows (DOT provided) greater than an acre that are drainable may have their own storm water discharge permit.


A.   Pond Borrows

n  All pond borrows (wet or dry) during construction must have at least the perimeter protected by sediment control measures.  Plus, site specific considerations must be included if there is any dredging involved during construction.

n  Temporary stabilization and mulching will not be required on concave slopes within the borrow.  However, channels (in‑flow and/or out‑flow) will require stabilization and sediment control measures.

n  Seeding for pond borrows will be required on any disturbed area above normal design pool or ground water elevation.


B.   Wetland Mitigation Areas

n  Check the contract documents for the required seed mix or other special conditions. 

n  Refer to Pond Borrows (Section A, above) for guidance in areas of standing water and selected sections in Normal Borrows (Section C, below) for those areas which are dry during seeding.  In either case, all "normal" erosion and sediment control practices are required for wetland areas.


C.  Normal (Dry) Borrows

n  All normal borrows must be protected by perimeter sediment control measures, and are included for temporary erosion control measures if work is halted at that site for more than 21 days.


n  All normal borrows, purchased by fee title, shall be included in the area which is permanently seeded.  As such, a Notice of Discontinuation (NOD) cannot be processed until 70% of the permanent seeding is established.


n  Normal borrows obtained by temporary easement:

1.   That require replacement of topsoil AND are used for agricultural row crops.  The project engineer needs to ask the property owner if they want the area permanently seeded.

a.   If the property owner requests permanent seeding, provide that seeding.  In such situations, the NOD cannot be processed until permanent seeding is 70% established.

b.   If the property owner does not want permanent seeding, shape and place temporary seeding on the area.  In this case, because the property will be returned to agricultural row crop use, consider temporary seeding as complying with storm water requirements and proceed with the NOD accordingly.  Note: Other temporary sediment control measures in that area will have to be maintained until the project is accepted.


2.   For temporary easements NOT used for agricultural row crops, permanent seeding will be required.  (Examples of this situation would be permanent pastures, timberland, non‑farmed land, etc.)


Is snow considered temporary cover in the Storm Water regulations? 

 YES.  Storm water regulations are written recognizing that snow is a "temporary" preventive measure.  However, just because it snows may or may not fulfill a winter long stabilization and definitely will not comply as spring thaws begin.  As soon as the snow is gone, some other means of stabilization is required.  ("Gone" could be by melting, wind, or snow plow.)  Best advice is to keep working on some form of soil stabilization until it absolutely freezes so hard that work from then on will not be practical.


EXAMPLE:  If snow comes in late October and is blown off the site by mid December, then some other form of temporary stabilization is required from that point forward. 


Plan notes have designated a plant site within Iowa DOT ROW.  Further, the contractor is told it is their responsibility to provide a permit #3 for this activity.  Who is ultimately responsible?

The contractor is responsible for that portion of area designated as the "plant site."  When this situation occurs, modify the project PPP by note in a storm water site inspection report to exclude the plant site when the contractor's NOI becomes effective.