What is an Environmental Assessment (EA)?

An Environmental Assessment (EA) is a public document prepared to determine whether a project would significantly affect the quality of the human and natural environment. An EA includes:

• identification of a proposed action and the purpose and need for the project;
• identification of alternatives including the no-action alternative;
• evaluation of the potential impacts - both positive and negative - on resources in the human and natural environment; and
• identification of appropriate mitigation measures in accordance with the National Environmental Policy Act (NEPA)

An EA does not need to evaluate in detail all reasonable alternatives, and can be prepared for only one proposed build alternative.

What will the EA process lead to?

Near the conclusion of the EA study process, which includes public meetings and other forms of contact, an EA document that identifies a preferred alternative is published. A 30-day public review and comment period is provided, and a public meeting held. Based on the results of the EA and the public input received during the comment period, the Federal Highway Administration (FHWA) issues a decision document. If no significant impacts are identified from comments received during the public comment period on the EA, the FHWA issues a Finding of No Significant Impact (FONSI). If significant impacts are identified, the SDDOT could decide to proceed with preparation of an Environmental Impact Statement (EIS).

The project would then move forward into a design phase. As federal funding becomes available, rights-of-way would be purchased, utilities relocated, and the identified transportation improvements would be constructed.

MORE INFO: Information on the Environmental Assessment (EA) Document for the I-90 Environmental Assessment (Exit 40 to Exit 51) can be found on the EA Document page.