Where a statute provides a formal process for promulgating policies with legal force (such as Part III of the EPA Act), policies generated by the decision-maker outside that process are permissive, not mandatory, relevant considerations. A decision-maker has no obligation to explain why it did not take into account something it was not obliged to consider, and a claim of legal unreasonableness on that basis must fail. When assessing whether an EPA process was unreasonable, the entire staged assessment process (including the environmental scoping document and public environmental review) must be considered, not just the final assessment report in isolation.
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