Supplemental Environmental Assessment (SEA) Finalized

The 24th Street Interchange SEA was prepared and published for agency and public review on July 23, 2026. UDOT has determined that this project will not have a significant impact on the natural environment or the human environment. This Finding of No Significant Impact is based on the attached Supplemental Environmental Assessment, which has been evaluated by UDOT and determined to discuss the Need, environmental issues, and impacts of the proposed project and appropriate mitigation measures adequately and accurately.

Read the FONSI

Study Overview

The Utah Department of Transportation (UDOT) prepared a Supplemental Environmental Assessment (SEA) consistent with the National Environmental Policy Act of 1969, as amended, (NEPA) and 23 Code of Federal Regulations (CFR) 771 to evaluate whether proposed improvements to the transportation network at and around Interstate 15 (I-15) and 24th Street in Ogden, Weber County, Utah, would have significant environmental impacts. Collectively known as the 2026 Proposed Action, the proposed improvements include replacing the partial interchange at I-15 and 24th Street with a folded diamond interchange to provide northbound and southbound access to and from I-15 and making other changes to the local roadway and active transportation systems. The Utah Department of Transportation (UDOT) prepared a Supplemental Environmental Assessment (SEA) consistent with the National Environmental Policy Act of 1969, as amended, (NEPA) and 23 Code of Federal Regulations (CFR) 771 to evaluate whether proposed improvements to the transportation network at and around Interstate 15 (I-15) and 24th Street in Ogden, Weber County, Utah, would have significant environmental impacts. Collectively known as the 2026 Proposed Action, the proposed improvements include replacing the partial interchange at I-15 and 24th Street with a folded diamond interchange to provide northbound and southbound access to and from I-15 and making other changes to the local roadway and active transportation systems.

This SEA builds upon the I-15; 24th Street Interchange Environmental Assessment (EA) and Finding of No Significant Impact (FONSI) that UDOT completed in 2024.  UDOT can provide copies of the 2024 documents for review upon request. The SEA updates portions of the earlier environmental analyses to reflect the revised interchange concept design and, where applicable, provides information that is new or different from the 2024 documents. Generally, if a topic is not addressed in the SEA, then the information or data provided in 2024 is still relevant. The SEA’s formal comment period and public hearing occurred in July and August 2026.

The environmental review, consultation, and other actions required by applicable Federal environmental laws for this project are being or have been carried out by UDOT pursuant to 23 U.S.C. 327 and a Memorandum of Understanding dated May 26, 2022, and executed by FHWA and UDOT.

Project Timeline