Environmental studies

Solutions for the Council Bluffs interstate system will balance engineering requirements with environmental and community issues. Federal, state and local environmental legislation and procedures will guide the evaluation of possible solutions.

The National Environmental Policy Act (NEPA) process is being followed in developing the environmental documentation for the Council Bluffs Interstate System (CBIS) improvements project. NEPA is the federal legislation that provides for the protection of our environment. The NEPA process for the CBIS improvements project is being conducted in two tiers.

Tier 1 focused on the entire interstate system, identifying the needs of the system and developing alternatives to meet those needs. An Environmental Impact Statement (EIS) was prepared to document the system study and the potential environmental impacts of implementing the Construction Alternative (the preferred alternative).

• Tier 1 Draft Environmental Impact Statement


• Tier 1 Final Environmental Impact Statement


• Record of Decision

Due to the magnitude of the improvements identified during Tier 1, the interstate system was divided into segments for further study in Tier 2. Tier 2 is focused on detailed engineering and environmental studies for each segment. Currently, environmental documents are being prepared for three segments:

• Segment 1 – Environmental Assessment – The Environmental Assessment was signed on October 31, 2006. A Finding of No Significant Impact (FONSI) was signed by FHWA on June 14, 2007.
  Tier 2, Segment 1 Environmental Assessment
  Tier 2, Segment 1 Finding of No Significant Impact
  
  
• Segment 2 – Categorical Exclusion – A categorical exclusion was signed by FHWA on Sept. 9, 2008.
  Tier 2, Segment 2 Categorical Exclusion
  
  
• Segment 3 – Environmental Assessment – The Environmental Assessment was signed on March 14, 2011. A Finding of No Significant Impact (FONSI) was signed by FHWA on August 23, 2011.
  Tier 2, Segment 3 Environmental Assessment
  Tier 2, Segment 3 Finding of No Significant Impact

The level of environmental documentation varies from segment to segment based on the level of impacts anticipated from the project.  A project documented by a categorical exclusion is expected to have minimal impacts and the level of documentation reflects the minimal amount and extent of impact.  A project documented by an environmental assessment is expected to have impacts that aren’t significant and the environmental assessment is more detailed than a categorical exclusion.  Projects documented by environmental impact statements are typically large, complex projects that have the potential to cause significant impacts.  If during the development of the documentation the degree or extent of impacts are greater than anticipated, the level of documentation can change to provide a higher level of review.