Location & Environment

What We Do

Our core

The core function of the Location and Environment Bureau is to balance transportation project delivery, regulatory compliance, and environmental stewardship for Iowa’s transportation interests.

Environmental stewardship is caring for natural, physical, cultural, and social resources.

Our employees are our greatest asset in accomplishing our core function. LEB combines expertise from the engineering, environmental, historical, and scientific fields to help define the best transportation improvement strategy for any given project.

Air Quality/Traffic Noise/Vibration


The Clean Air Act (CAA) requires that transportation planning be consistent with air quality goals. EPA and FHWA provide guidance on transportation conformity regulations and resources.

Transportation agencies have a role to play in insuring conformity with the NAAQS.

Noise Evaluation

As part of the environmental process, Iowa DOT determines if a noise study is warranted per federal code (23 CFR 772) and Iowa DOT noise policy (PPM 500.07). If a noise study is warranted, qualified individuals will conduct a noise study to determine whether or not there are noise impacts. This process involves noise modeling the proposed highway project using the Traffic Noise Model (TNM).


In everything we do at the Iowa DOT, our focus is not only on helping you get where you need to go, we are also committed to doing everything we can to protect the environment.

As part of that commitment, we have a dedicated group of professionals who work with the Iowa Department of Natural Resources and our own internal experts to ensure that the facilities we use and the constructions project we build to comply with all applicable federal and state laws and best practices related to air quality, noise impacts, and vibration issues.

Cultural Resources

Cultural Resources Consultation

The Iowa DOT, often in cooperation with the Federal Highway Administration, works to identify and consult with various interested parties as part of compliance with the National Historic Preservation Act (NHPA) of 1966 (as amended).

Referred to as the Section 106 process, consultation as part of the NHPA enables various interested groups to voice their concerns about potential impacts to historic properties by Iowa DOT and FHWA projects. For example, the Iowa DOT seeks input from federally recognized Native American tribes and nations who have a historic or ancestral connection to the State of Iowa.

The Iowa DOT and FHWA also seek to involve the public in the Section 106 process. If you or your organization wishes to provide information about a historic property or act as a consulting party, please contact one of our cultural resources staff.

Location Design/Project Planning

Iowa Highway

Project development in the context of environmental stewardship is a balancing act and sometimes complicated depending on the resources in the area of a potential highway project. On larger projects that have greater potential for environmental impacts, staff within the Project Planning and Location Design section of the office guides this development through planning, preliminary engineering, and regulatory compliance.

This work involves the planning and development of larger projects from initial concept and classification through preliminary engineering state and federal approvals and occasionally beyond. Highway project planning and design considers the potential environmental, social, and economic impacts of transportation improvements within the area of study and tries to balance the impacts with the purpose and need for the project.

Staff within the section are also responsible to coordinate, develop and present projects at all stages of project development and vet the potential improvements with Iowa DOT management, the public, and other state and local agencies.

The future is not something that just happens it is something that has to be planned for. Staff within the Project Planning & Location Design section help plan for Iowa’s future one project at a time.

Mitigation Design

Compensatory mitigation is required by the Federal Clean Water Act and Iowa Code when a protected natural resource, such as wetlands, streams, woodland, threatened or endangered species etc. are impacted by a DOT project.  Compensatory mitigation measures are developed by a multidisciplinary team consisting of engineers, biologists, and a design technician.

National Environmental Policy Act (NEPA)

Documentation is an essential component of the National Environmental Policy Act (NEPA) project development process, which supports and complements public involvement and interagency coordination.

NEPA requires federal agencies disclose the results of their analysis, consider the effects of project implementation on the environment and solicit comments on the proposals from interested and affected parties. For transportation projects, the Federal Highway Administration (FHWA) has jurisdiction over preparation of NEPA compliance products. This responsibility is delegated by FHWA to the state department of transportation and includes all projects that receive either federal funding or require a specific federal action.

The purposes for documenting the NEPA process include:

  • Providing for complete disclosure to the public.
  • Allowing for an opportunity to provide input and comment on proposals, alternatives and environmental impacts.
  • Providing the appropriate information for the decision maker to make a reasoned choice among alternatives.

Classes of Action

Transportation projects vary in type, size, complexity, and potential to affect the human and natural environment.

To account for the variability of project impacts, three basic "classes of action" are allowed and determine how compliance with NEPA is carried out and documented.

An environmental impact statement (EIS) is prepared for projects where it is known that the action will have a significant effect on the environment. The following are examples of actions that normally require EIS.

  • A new controlled access freeway.
  • A highway project of four or more lanes on a new alignment.
  • New construction or extension of fixed-rail transit facilities.
  • New construction or extension of a separate roadway for buses or high-occupancy vehicles not located within an existing highway facility.

An environmental assessment (EA) is prepared for actions in which the significance of the environmental impact is not clearly established. Should environmental analysis and interagency review during the EA process find a project to have no significant impacts on the quality of the environment, a finding of no significant impact (FONSI) is issued. If during processing of the EA., it is determined that significant impact will occur; an environmental impact statement will be prepared.

Categorical exclusions (CEs) are issued for actions that do not individually or cumulatively have a significant effect on the environment.  

Public involvement

Federal and state regulations require public involvement activities during project development. Each public involvement opportunity allows the public a chance to provide ideas and comments regarding the development of a transportation project. Because transportation projects can greatly affect a community, public input is extremely important. Listed below are the most common public involvement events.

Public information meeting

Public information meetings are held at different stages of project development.  A meeting may also be held to discuss a detour, a road closure, or right of way needs.  The meeting is held as an open forum so attendees can see displays, ask questions and share concerns directly with Iowa DOT staff.  During and after the meeting, individuals are encouraged to send in written comments or leave comments online regarding the project or detour.

Public hearing

A public hearing is held when an environmental document has been prepared and is available for the public to review.  An environmental document compares different project alternatives and their influence on the environment.  The hearing involves a formal presentation made by Iowa DOT staff.  An open forum, where attendees may ask their questions directly to Iowa DOT staff is also part of the Public Hearing.  The formal presentation is recorded and included in the final record.  During and after the meeting, individuals are encouraged to send in written comments or leave comments online regarding the project.  

Regulated materials

The Regulated Materials Section works with a variety of issues related to known or potentially contaminated sites, investigations for and the handling of hazardous materials, and the collection and disposal of special wastes. These issues include:

  • Highway Project Reviews
  • Hazardous Materials
  • Underground Tanks
  • Hazardous Wastes
  • Special Wastes

Threatened & Endangered Species

The Threatened and Endangered Species section of OLE is responsible for ensuring Iowa DOT projects do not endanger or harm state and federally protected species or destroy their habitat. There are 13 federally listed animals and five plants within Iowa. The State of Iowa has listed an additional 72 animals and 150 plants that are threatened or endangered. During the planning phase of each project, the area is evaluated to determine the potential for each plant or animal to be found on the site. If the animal or plant is found in or near the project boundaries, steps are taken to avoid or mitigate any potential impacts to them. One example of a species needing special consideration by our office is the Topeka shiner a small minnow.

Water Resources

Many of the documents OLE prepares are completed to meet federal standards. Some of these documents are:

  1. Section 404 permits of the Clean Water Act
  2. National Environmental Policy Act (NEPA) documents
  3. Section 4(f)
  4. Interchange Justification Reports (IJR)
  5. National Historic Preservation Act (NHPA) compliance

The Section 404 permit is part of the Clean Water Act. Its goal is to, "regulate the discharge of dredged or fill material into waters of the United States, including wetlands. Regulated activities include fills for development, water resource projects, infrastructure development, and conversion of wetlands to uplands for farming and forestry." So if a wetland or stream is unable to be avoided by a road project, OLE applies for a permit from the Army Corps of Engineers. In this permit, OLE staff outlines the effort to avoid the impact and the plan to mitigate for any loss.

When appropriate, the reports are shared with the public and many different local, state and federal agencies having an interest in the protection of Iowa's resources — both natural and cultural. The Iowa DOT will not make important decisions about the location or design features of any highway improvement project being planned without first giving careful consideration to this information and making sure the project will cause as little harm to the environment as possible. The reviewing resource agencies, and the public, will have an opportunity to send comments to the Iowa DOT after reading the reports.


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