Environmental Studies

Air Quality

The Clean Air Act (CAA) requires each state to develop a state implementation plan, which establishes air quality objectives and regulations that the state will follow.

Community Impact

Community Impact Assessment is a process that helps us understand how a proposed transportation activity may impact the local communities and the individuals within them.

Farmland Protection

Missouri has a long history of farming. MoDOT minimizes its impact to Missouri’s farmland in order to help preserve it for the present and for future generations.

Floodplain Management

Floodplains provide a number of important functions in the natural environment. MoDOT avoids or minimizes encroachment into floodplains whenever possible in order to preserve these values for the future.


The National Environmental Policy Act (NEPA) calls for all environmental protection requirements and enhancement goals to be completed as part of a coordinated review process.

Noise Assessment

Public concern about noise led to federal legislation in 1970 that authorized the use of federal-aid highway funds for measures to abate and control highway traffic noise.

Public Lands Consideration

MoDOT considers the impact on using public land in the planning process, and then attempts to minimize and mitigate when impacts are unavoidable.

Hazardous and Solid Waste

MoDOT frequently encounters properties containing hazardous and nonhazardous solid wastes. MoDOT specialists evaluate project corridors for waste sites, provide management and oversight of waste sites acquired, and monitor projects for compliance with applicable laws and regulations.

Threatened Species

MoDOT considers the impact its projects will have on threatened and endangered species, which includes potential impacts to rare plants, animals, critical habitat, and unique natural communities.

Water Quality

MoDOT is responsible for implementing control measures to prevent the excessive release of sediment and pollutants into nearby waterways whenever one acre or more of land is disturbed for roadwork.

Wetlands Protection

MoDOT evaluates every project and determines whether the project could have a negative impact on any waters of the U.S. including wetlands, streams, and special aquatic sites.

As good stewards of the environment, MoDOT strives to be environmentally conscious with all of its transportation projects. Also, in order to comply with national and state environmental legislation, MODOT is mandated to consider the potential impacts of its projects on our state’s natural and social resources. Legislation such as the National Environmental Policy Act (NEPA) of 1969 was passed in response to growing public concern for the environment. NEPA establishes a national policy to protect the environment, which includes the assessment of potential environmental impacts of all major federal actions.

MoDOT’s staff of natural and social science specialists are responsible for evaluating the impacts of all transportation projects on Missouri’s diverse array of natural resources. Those resources include: floodplains, wetlands, sensitive species, farmland, air and water quality, and wildlife habitats. MoDOT personnel also address concerns relating to noise and hazardous wastes.  Furthermore, the Federal Highway Administration has established additional requirements for the protection and enhancement of resources such as publicly owned parks, recreation areas, and wildlife and waterfowl refuges. MoDOT must also consider all social and economic impacts of its projects on the human environment. After completing their environmental assessments, staff specialists will assist MoDOT's district personnel in avoiding, minimizing, or mitigating project impacts on the natural and human environment.