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It is critical to consider the natural environment when accounting for the short- and long-term impacts of transportation decisions.


It is critical to consider the natural environment when accounting for the short- and long-term impacts of transportation decisions. In connection with new approaches to how we maintain and enhance the livability of our region, current Federal and State transportation legislation reconfirm the need to enhance the performance of transportation systems while protecting and enhancing the natural environment as one of its primary goals. Managing environmental resources as a group of strategic assets that are crucial to municipal goals, important to ecosystem health, and beneficial to the region is key to successful regional management. Key environmental assets include but are not limited to:

  • Air
  • Water
  • Biodiversity
  • Natural Areas

The natural environment provides the region with several ecosystem services which are fundamental to urban livability. In considering environmental resources, these benefits may be managed and increased by planning transportation networks in a way that preserves, unifies, and invests in these natural systems.


Climate change cause by human activities is a growing global threat. The National Oceanic and Atmospheric Administration (NOAA) projects ongoing increases in Illinois temperatures and extreme precipitation events depending on future levels of greenhouse gas emissions1. These climate changes and their impact on many industries and different aspects of life are important to consider when planning for the year 2045.

At the national level, the transportation sector accounted for the largest portion of total U.S. greenhouse gas emissions in 2017. The most recent data for Illinois shows a similar pattern: in 2016 the transportation sector accounted for the largest share of carbon dioxide emissions. While all types of vehicles contribute to transportation sector emissions, the passenger cars and light-duty trucks most area residents rely on every day are responsible for the majority of emissions within the transportation sector.

Climate change can impact air quality, and air quality can also impact climate change. For instance, ozone in the atmosphere warms the climate, while different components of particulate matter (PM) can have either warming or cooling effects on the climate2.

The Champaign-Urbana Urbanized Area maintains an overall “attainment status” for locally measured air pollutants, which means that air quality in the Champaign-Urbana Metropolitan area meets federal air quality standards. The 2017 Air Quality Index for the Metropolitan Area shows 78.4 percent of days were measured as having Good air quality, 21.4 percent were measured as “Moderate”, and 0.3 percent were considered “Unhealthy for Sensitive Groups.” The Air Quality Index represents a summary assessments for six different air pollutants carbon monoxide, nitrogen dioxide, ozone, sulfur dioxide, and two forms of particulate matter (PM2.5 and PM10).

Together with the U.S. Environmental Protection Agency (EPA), the Illinois EPA monitors the concentrations of the six airborne pollutants represented in the Air Quality Index as well as a seventh, lead. Four of these pollutants are measured in Champaign County. The most comprehensive monitoring site in the County is in Bondville, monitoring carbon monoxide, one form of particulate matter (PM2.5), ozone, and sulfur dioxide. Due to its distance from the urbanized area and the prevailing winds from the south-southwest, the Bondville site is categorized as a rural National Core Pollutant Monitoring site (NCore), rather than an urban monitoring site. Champaign County has two additional air monitoring sites, one in the City of Champaign that monitors one form of particulate matter (PM2.5) and one in Thomasboro that monitors ozone. Lead, nitrogen dioxide, and particulate matter (PM10) are not monitored in Champaign County.

The following table provides a summary of each pollutant measured by the Illinois EPA, alongside the primary national standards and local monitoring stations. “Primary Standards” refer to air quality levels required to protect public health with an adequate margin of safety.

Carbon Monoxide

Carbon monoxide is produced when fuel or other carbon-based materials are burned. The main source of carbon monoxide emissions is motor vehicles. The U.S. EPA sets emissions standards for new motor vehicles while the State of Illinois focuses on overseeing transportation plans for congested urban areas as a strategy for reducing carbon monoxide in the air.

The 1-hour and 8-hour carbon monoxide standards are set at 35 parts per million (ppm) and 9 ppm, respectively, and are not to be exceeded more than once per year. The Bondville monitoring station did not record any exceedances of the 1-hour or 8-hour standards between 2013 and 2018.

Nitrogen Dioxide

Currently, there are no nitrogen dioxide monitoring sites in Champaign County. According to the Illinois EPA, there were no violations of the nitrogen dioxide standards recorded in Illinois between 2008 and 2017.


Ground level ozone is a secondary air pollutant produced by chemical reactions in the environment with man-made factors such as vehicle exhaust, gasoline vapors, and industrial emissions. Two main pollutants, nitrogen oxides and volatile organic compounds, contribute to ground level ozone pollution. Heat serves as a catalyst to accelerate ozone-forming reactions.

The 8-hour ozone standard is set at 70 parts per billion (ppb), measured by the three-year average of the annual fourth-highest daily eight-hour concentration maximum, effectively permitting three exceedances per year. Ozone monitoring stations in Champaign County recorded one 8-hour measure of ozone above 70 ppb in 2017, but the 3-year average of the fourth-highest eight-hour measures remained below the national standard.

Sulfur Dioxide

A large portion of sulfur dioxide pollution results from burning fossil fuels containing sulfur compounds. The use of low- sulfur content fuels and the use of chemical sulfur removal systems have been effective at reducing sulfur dioxide pollution levels.

The Bondville monitoring station shows local levels of sulfur dioxide to be considerably below the national standard and steadily declining between 2013 and 2017.


Historically, motor fuel was the primary source of lead air pollution. Through effective air quality control measures, leaded gasoline was phased-out of the market beginning in the mid-1970’s. The result was approximately a 90 percent reduction in lead air pollution. This demonstrates that changes in transportation emissions regulations can have a significant impact on the environment.

Currently, there are no lead monitoring sites in Champaign County. According to the Illinois EPA, there were no violations of the lead standard recorded in Illinois between 2008 and 2017.

Particulate Matter

Particulate matter is a type of airborne pollutant consisting of small liquid or solid particles in the atmosphere. Unlike other pollutant categories, particulate matter does not designate a specific chemical composition. Major sources of PM2.5 result from burning or combustion activities such as the burning of fossil fuels, smelting, and forest fires. In the context of Champaign County, it is important to note that ammonia from agricultural sources such as fertilizer and animal feed operations contributes to the formation of sulfurous and nitrogenous particulate matter that exists in the atmosphere1.

Within the last decade, Champaign County monitoring stations have recorded no exceedances of the annual or 24-hour standards for PM2.5. In addition, the three-year averages of PM2.5 in the county have been steadily decreasing since 2011. PM10 is not currently monitored in Champaign County. According to the Illinois EPA, there were no violations of the PM10 standards recorded in Illinois between 2008 and 2017.


The Illinois EPA evaluates water quality compliance based on support, or attainment, of each designated use. Water quality information is based on the Illinois EPA’s biannual Illinois Integrated Water Quality Report and Section 303(d) Lists. These documents offer information related to the condition of surface water as required by the federal Clean Water Act. The assessments contained in these reports primarily come from biological, water, physical habitat, and fish-tissue data collected through monitoring programs across the state. Due to limited resources, the Illinois EPA typically assesses approximately 15 percent of Illinois stream3 miles for at least one designated use during every reporting cycle. Within the Metropolitan Planning Area, aquatic life, fish consumption, and primary contact are the most frequently observed designated uses. A stream is classified as “impaired” if it cannot support any one of its designated uses. Impaired streams are placed on the 303(d) list, starting the recovery process. Streams on the 303(d) list require additional data collection and a priority ranking for establishing a total maximum daily load (TMDL).

Water quality in the region has had and continues to have mixed results. In the Illinois EPA’s 2018 Integrated Water Quality Report, seven streams received an impaired classification, while five fully supported their designated uses. Limited assessments indicate no streams in the MPA support fish consumption or primary contact. Boneyard Creek, both segments of Hackett Branch, and Saline Branch segment IL_BPJC-08 have consistently failed to support aquatic life since 2008. Saline Branch segment IL_BPJC-06 was previously on the 303(d) List, but has maintained support of its designated uses since 2010. Two streams in the region, Union Drainage Ditch and Phinney Branch, have not been assessed for many years.


Natural areas like grasslands, woodlands, and wetlands provide optimal conditions for many native plant and animal species. Native species depending on these specific habitats become vulnerable as these habitats are lost to development, pollution, and a changing climate. In July 2018, there were a total of 33 threatened and endangered species in Champaign County identified by the Illinois Department of Natural Resources (IDNR). This is an increase from 22 threatened and endangered species in 2013 and 17 species in 2009. Plant species experienced the most significant change in threatened and endangered listings, more than tripling in number since 2013.

It is worthwhile to note that some species classified as threatened or endangered in Champaign County may be more prevalent in other regions of the country or world. Global classifications from the International Union for Conservation of Nature Red List of Threatened Species (IUCN Red List) assist in differentiating which species are of most concern both globally and locally. Established in 1964, the IUCN Red List is one of the most comprehensive information sources on global conservation. In Champaign County, two animal species were both globally and locally endangered: the Rusty Patched Bumble Bee and Blanding’s Turtle.

Natural Areas

The Illinois Natural Heritage Database is an indispensable resource for identifying significant natural areas. Maintained by the Illinois Department of Natural Resources, this database contains detailed information on wildlife and natural areas including, threatened and endangered species habitat locations, the Illinois Natural Areas Inventory (INAI), and lands with Illinois Nature Preserves Commission (INPC) protection. The INAI designates and classifies high-quality land, whereas the INPC establishes protection for high-quality land. The INAI guides INPC determination, however not all recognized natural areas are also protected. Eleven natural areas within the metropolitan planning area are classified in the Illinois Natural Heritage Database: seven INAI sites and four INPC sites. Seven of the natural areas are within the greater Mahomet area, two natural areas are northeast of Urbana, and two natural areas are directly south of Urbana.

In 2018, land cover within the metropolitan planning area consisted of approximately 76,000 acres of agricultural/grassland, 36,400 acres of urban landscape, 4,000 acres of wooded areas, and 1,800 of wetlands and other water bodies2,4,5. Wetlands, in particular, greatly assist in reducing the effects of regional flooding during times of heavy precipitation, in addition to providing habitat for specific types of vegetation and animal species not found in other environments. Since the previous long-range transportation plan, wetlands and water bodies have not changed significantly. The wetland and water total acreage has increased, but much of this change is attributed to changes in the MPA boundary.

  1. The Particle Pollution Report: Current Understanding of Air Quality and Emissions through 2003. Neil Frank. 2006. The Chemical Composition of PM2.5 to support PM Implementation. AQAG/AQAD USEPA. Pomporn Chantara. 2012. PM10 and Its Chemical Composition. Chiang Mai University. [return]
  2. United States Fish and Wildlife Service, National Wetlands Inventory, Accessed 12/7/2018 [return]
  3. In the Illinois water quality reports, streams encompass a variety of water bodies including rivers, creeks, sloughs, and branches. [return]
  4. National Agricultural Statistics Service, 2018 CropScape - Cropland Data Layer, Accessed 2/26/2019 [return]
  5. Data has been collected from multiple sources. As a result, MPA acreage is an approximation and may contain some overlap between categories. [return]