(a) Generally. The District Engineer may rely on an environmental impact statement, environmental assessment, or portion thereof, provided that the statement, assessment, or portion thereof meets the standards for an adequate statement or assessment under these procedures. When relying on an environmental impact statement, environmental assessment, or portion thereof, the District Engineer will cite, briefly describe the content and relevance to the environmental document, and may make modifications that are necessary to render the relied-upon document, or portion thereof, fit for fulfilling NEPA's analytic requirements for the action. If the District Engineer finds that the other agency's environmental impact statement or environmental assessment is inadequate with respect to the Corps permit or permission action, the District Engineer should incorporate the other agency's NEPA document or a portion thereof and prepare an appropriate and adequate NEPA document to address the Corps involvement with the proposed action.

(b) Substantial similarity. (1) If the actions covered by the original environmental impact statement or environmental assessment and the proposed action are substantially the same, the District Engineer will document their reliance on the statement or assessment.

(2) If the actions are not substantially the same, the District Engineer may modify the statement or assessment as necessary to render the statement fit for fulfilling NEPA's analytic requirements for the action at hand, and document the reliance on the statement or assessment, as modified, or may incorporate relevant portions in the District Engineer's own NEPA document. Where appropriate, the District Engineer may solicit comment to the extent that solicitation of comment will assist the District Engineer in expeditiously adapting the relied-upon statement or assessment so that it is fit for the District Engineer's purposes.