Section 1506.6 - Methodology and scientific accuracy(a) Agencies shall ensure the professional integrity, including scientific integrity, of the discussions and analyses in environmental documents.(b) In preparing environmental documents, agencies shall use high-quality information, including reliable data and resources, models, and Indigenous Knowledge. Agencies may rely on existing information as well as information obtained to inform the analysis. Agencies may use any reliable data sources, such as remotely gathered information or statistical models. Agencies shall explain any relevant assumptions or limitations of the information or the particular model or methodology selected for use.(c) Agencies shall identify any methodologies used and shall make explicit reference to the scientific and other sources relied upon for conclusions in the environmental document. Agencies may place discussion of methodology in an appendix.(d) Where appropriate, agencies shall use projections when evaluating the reasonably foreseeable effects, including climate change-related effects. Such projections may employ mathematical or other models that project a range of possible future outcomes, so long as agencies disclose the relevant assumptions or limitations. 85 FR 43370 , 9/14/2020; 89 FR 35554 , 7/1/2024