From the Advisory Council on Historic Preservation (ACHP):

Revised National Environmental Policy Act (NEPA) regulations from the Council on Environmental Quality (CEQ) went into effect on September 14, 2020. While the relationship between NEPA and Section 106 reviews remains fundamentally the same, the ACHP developed this Environmental Impact Statement (EIS) flow chart in coordination with CEQ to serve as a reference for how the two reviews align. It includes updated NEPA citations and definitions of key terms in NEPA and Section 106.

This chart serves as a supplement to NEPA and NHPA: A Handbook for Integrating NEPA and Section 106 (Handbook), jointly developed by CEQ and the ACHP in 2013. More thorough updates to the Handbook will be carried out in the future. For additional information on NEPA and Section 106 review integration, please visit the ACHP's website: https://www.achp.gov/integrating_nepa_106.