The environmental impacts of Alternatives B5 and B2 were very similar, both in terms of resources affected and the extent of the impacts.  While the appropriate mitigation of the impacts identified in the DEIS is important to the implementation of the preferred alternative, environmental impact is not a substantial factor in choosing between the two build alternatives.  For some factors of environmental impact Alternative B5 with IL-47 Widening has somewhat greater impacts because of its longer length, but was also considered to be consistent with State Farmland Preservation policy, which was not the case with Alternative B2.  The selection of Alternative B5 has the concurrence of state and federal environmental oversight agencies including U.S Environmental Protection Agency, U.S. Fish and Wildlife Service, U.S. Army Corps of Engineers, Illinois Environmental Protection Agency, Illinois Department of Natural Resources, Illinois Department of Agriculture and Federal Highway Administration.  

Other considerations include:

• Water quality and water resource impacts similar, but impact different watersheds.  Alternative B5 passes along the Aux Sable watershed, Alternative B2 passes through the Nettle Creek watershed.
• Both alternatives impact less than 3 acres of wetlands.
• When a preference was indicated by local government, it was overwhelmingly for Alternative B5, with 9 local governments supporting B5 and one in support of B2.
• Alternative B5 has greater compatibility with local land use plans and is adopted in local land use plans.  Alternate B2 impacts sustainable agricultural areas.
• South of Caton Farm Road, approximately one-half of the estimated right-of-way for B5 lies within planned development areas, while B2 passes though agricultural areas.
• Alternative B5 is consistent with the IDOT's Agricultural Land Preservation Policy, and in compliance with the State's Farmland Preservation Act.
• Both alternatives will result in the relocation of 22 residences. Of these relocations, 9 are caused by the widening of IL 47.  
• Population and employment added by the either option is expected to be concentrated around the state highway interchanges.  Little added growth is expected at the I-80 and I-88 interchanges because no new access is proposed.
• Alternative B5 has less adverse travel due to road closures.