10.30 STORM WATER DISCHARGE
Effective March 10, 2003, all construction projects that disturb 1 acre or more are required to have a storm water 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 for projects where the DOT is the Contracting Authority:
n Construction projects or groups of projects (such as corridor projects) which disturb 1 acre or more are identified by the designer. It is the designer’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 Contracts Bureau tabulates projects with PPPs. The designer sends NOIs and newspaper notice to the Construction and Materials Bureau.
n The Construction and Materials Bureau forwards required notice to appropriate newspaper for publication. Once publication verification is returned, the Construction and Materials Bureau assembles all parts for NOIs and completes the application to Iowa DNR.
n Upon receipt of the permit authorization from the DNR, the Construction and Materials Bureau uploads a copy of the permit authorization to Doc Express (Contract Documents or Environmental drawer). (The contractor should not begin work until permit coverage is obtained.)
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.
10.31 NOTICE OF INTENT (NOI)
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) (or oftentimes referred to as the storm water permit number) to the Construction and Materials Bureau.
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 Construction and Materials Bureau receives a renewal reminder from the DNR, the project engineer is contacted to inquire if a permit should be renewed. If renewal is requested, the Construction and Materials Bureau 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 Construction and Materials Bureau by uploading the signed NOD to DocExpress in the Environmental or Contract Documents drawer (Note: Submitting NOD to Construction and Materials Bureau 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 Construction and Materials Bureau). If a project’s soil disturbing activities are complete "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 available at https://iowadot.gov/consultants-contractors/construction-materials/inspection-tools#environmental ). This form is used for DOT-administered projects.
n Are the project’s soil disturbing activities 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.
10.32 TYPES OF STORM WATER PERMITS
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 Construction and Materials Bureau’s website
https://iowadot.gov/consultants-contractors/construction-materials/faq/environmental .
10.33 ADMINISTERING PROJECTS WITH STORM WATER DISCHARGE PERMITS
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, and 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 Contracts Bureau (located in DocExpress, Contract Signing drawer). It is the prime contractor’s responsibility to obtain and upload to Doc Express (Environmental or Contract Documents drawer) signed certificates for the subcontractors to the project engineer. The co-permittee certificate form is available at https://iowadot.gov/consultants-contractors/construction-materials/inspection-tools#environmental). Co-permittee certification statements are required if the subcontractor is responsible for sediment or erosion controls, if they are involved in land disturbing activities, or if they are performing work that is a source of potential pollution. Examples of subcontractors that would typically not require a co-permittee certification statement include 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. These inspections are a permit requirement. Inspection staff and contractors are to perform joint inspections and document findings on the Storm Water Site Inspection Report (Form 830214). This form is available at https://iowadot.gov/consultants-contractors/construction-materials/inspection-tools#environmental . Completed forms should be uploaded to DocExpress (Environmental or Signature drawer). Both the inspector and contractor representative are required to be either ESC Basics trained or a certified ECT and are required to sign the inspection report. 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 required to mobilize to perform required erosion and sediment control features within 3 working days and complete work within 7 calendar days following inspection.
Additionally, on projects that disturb 5 acres or more where the DOT is the Contracting Authority, Quality Assurance (QA) inspections should be performed at least one every 120 days during active construction. These inspections are not a permit requirement but were started as a result of a consent order.
Information on inspections can be found here:
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 requires 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., DOT provided 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.
n Projects with storm water permit coverage that are located within a MS4 (Municipal Separate Storm Sewer System) may have someone from the city perform quarterly inspections as part of the city’s MS4 permit with the Iowa DNR. Access to the site and storm water permit records should be provided to city staff. A list of MS4 permittees is provided at: https://www.iowadnr.gov/environmental-protection/water-quality/stormwater-program/ms4-required-permitees
10.34 QUESTIONS OFTEN ASKED
The weather is not favorable to establish temporary seeding or silt fences. What do we do?
A. Stabilization:
Specifications say if an area will not have any activity for 14 or more days; some form of stabilization will be required to be initiated immediately. There is very little latitude in that statement even if it is wet or freezing. Snow or frozen ground are NOT considered temporary stabilization. Sediment controls, like silt fence, are also NOT considered temporary stabilization.
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 very least keep it to a minimum so if one of the other alternates is necessary, costs can be kept to a minimum.
The specifications also provide seed mixes for rural stabilizing that may be placed year-round.
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 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?
Onsite borrows provided by the DOT will be covered under a project’s storm water discharge permit. Offsite borrows that are DOT provided and greater than an acre may have their own storm water discharge permit.
Contractor furnished borrows are not covered under a project’s storm water discharge permit. Rather, it is the contractor’s responsibility to obtain the coverage.
The contractor set up a plant site within Iowa DOT ROW. Who is responsible?
As noted in Construction Manual 10.33, 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 Permit #3 coverage becomes effective.
When are storm water site inspections required?
Weekly site inspections are required when a project is covered by a storm water permit. “Weekly inspections” means at least once every seven calendar days. These inspections should begin once ground is disturbed. The permit does not allow for suspension of weekly inspections during the winter. Rainfall inspections are no longer required by the permit. However, the weekly inspection form includes precipitation data. A good resource for this information is: https://mesonet.agron.iastate.edu/request/coop/obs-fe.phtml