36 CFR Section 800.8(c) of the NHPA Section 106 regulations allows "use of the NEPA process for Section 106 purposes." Under this subsection, an agency can use the NEPA process and the documents it produces "to comply with Section 106 in lieu of the procedures set forth in Secs. 800.3 through 800.6." This may be a way for an agency to streamline its overall environmental/historic preservation review process. To use this provision, however, the agency and its NEPA work must meet the following tests.
- The agency must notify the SHPO/THPO and ACHP that it intends to substitute.
- The agency has to identify consulting parties -- such as Indian tribes and Native Hawaiian groups, local governments, preservation organizations, and so forth -- in a manner consistent with Section 800.3(f).
- The agency has to identify historic properties and assess effects on them in a manner consistent with Sec. 800.4 through 800.5, but the scope and timing of identification and effect determination may be "phased to reflect the Agency Official's consideration of project alternatives in the NEPA process" and the effort the agency expends must be "commensurate with the assessment of other environmental factors."
- The agency must consult about the action's effects with the SHPO/THPO, tribes, Native Hawaiian groups, and other consulting parties during NEPA scoping, analysis, and documentation, and it must involve the public in accordance with the agency's NEPA procedures.
- The agency must develop alternatives and mitigation measures in consultation with the other stakeholders, and describe these measures in its EA or DEIS.
In other words, the agency must do the substantive things that the Section 106 regulations call for, but it doesn't have to follow precisely the same procedures it would if it were doing "standard" Section 106 review. It has the flexibility to do things in "phases," and the level of effort it puts forth is supposed to be similar to what it does for other kinds of environmental resources.
To guard against abuse of this flexibility, subsection 800.8(c)(2) requires that the EA or EIS be reviewed by the SHPO/THPO and other consulting parties. Any of these may object "prior to or within the time allowed for public comment." In the event of such an objection, the agency must refer the matter to the ACHP, which has 30 days to review the objection and decide whether it agrees with it. If it does, then consultation continues to resolve the objection, or the agency requests final ACHP comment. If the ACHP does not agree with the objection, or fails to respond within 30 days, the agency can complete its NEPA review and make its decision without further Section 106 review.
- Note, however, that when an agency does an EA, there isn't necessarily any public review period in which consulting party review and objection can take place. The Section 106 regulations don't say how to handle this problem.
Based on this consultation and review, subsection 800.8(c)(4) requires the agency to specify in its FONSI or ROD the measures it will take to mitigate adverse effects on historic properties. The agency must also "ensure that the approval of the undertaking is conditioned accordingly," and make "a binding commitment" to do so. Section 800.8(c)(4) goes on to say that "where the NEPA process results in a FONSI, the Agency Official must adopt such a binding commitment through a Memorandum of Agreement drafted in accordance with Sec. 800.6(c).