(a) In deciding whether to accept an alternative proposed under § 45.71 or 45.72, DOI must consider evidence and supporting material provided by any license party or otherwise reasonably available to DOI, including:

(1) Any evidence on the implementation costs or operational impacts for electricity production of the proposed alternative;

(2) Any comments received on DOI's preliminary condition or prescription;

(3) Any ALJ decision on disputed issues of material fact issued under § 45.60 with respect to the preliminary condition or prescription;

(4) Comments received on any draft or final NEPA documents; and

(5) The license party's proposal under § 45.71 or 45.72.

(b) DOI must accept a proposed alternative if it determines, based on substantial evidence provided by any license party or otherwise reasonably available to DOI, that the alternative:

(1) Will, as compared to DOI's preliminary condition or prescription:

(i) Cost significantly less to implement; or

(ii) Result in improved operation of the project works for electricity production; and

(2) Will:

(i) If a condition, provide for the adequate protection and utilization of the reservation; or

(ii) If a prescription, be no less protective than DOI's preliminary prescription.

(c) For purposes of paragraphs (a) and (b) of this section, DOI will consider evidence and supporting material provided by any license party by the deadline for filing comments on FERC's NEPA document under 18 CFR 5.25(c).

(d) When DOI files with FERC the condition or prescription that DOI adopts as its modified condition or prescription under § 45.73(a)(2), it must also file:

(1) A written statement explaining:

(i) The basis for the adopted condition or prescription;

(ii) If DOI is not accepting any pending alternative, its reasons for not doing so; and

(iii) If any alternative submitted under § 45.71 was subsequently withdrawn by the license party, that the alternative was withdrawn; and

(2) Any study, data, and other factual information relied on that is not already part of the licensing proceeding record.

(e) The written statement under paragraph (d)(1) of this section must demonstrate that DOI gave equal consideration to the effects of the condition or prescription adopted and any alternative not accepted on:

(1) Energy supply, distribution, cost, and use;

(2) Flood control;

(3) Navigation;

(4) Water supply;

(5) Air quality; and

(6) Preservation of other aspects of environmental quality.