An EIS assesses the potential impact of the selected alignment on the natural, man-made, and socioeconomic environments. The purpose is to determine any adverse impacts and to describe how the adverse impacts can be mitigated to acceptable levels.
Mitigation can take any number of forms.
In the most extreme case an alignment must be abandoned. This most commonly occurs before the Line and Grade Study is completed. Other forms of mitigation could include landscaping, sound barriers, special provisions for wildlife in the corridor and maintenance of traffic during construction. It is too early in the I-49 Planning Process for a list of required mitigation actions to be prepared. Included are the provisions of other Federal statutes requiring that the National Advisory Council on Historic Preservation be allowed to comment on any impacts to historic or archeological sites eligible for the National Register of Historic Places and that the Department of Interior review any impacts to parklands.