EPA Region X letter on conformity, mitigation measures, and cumulative impacts for Sea-Tac Airport EIS

This 1996 EPA letter addresses environmental conformity requirements for the Sea-Tac Airport expansion project, noting that projected increases in carbon monoxide pollution require mitigation measures or a phased development approach to meet federal air quality standards. It also calls on the FAA's Record of Decision to address cumulative environmental impacts from related regional projects, including the Sea-Tac expansion, the SR 509 proposal, and the South Aviation Support Area.

Notes

This EPA Region X letter addresses conformity requirements for the Sea-Tac Airport Final Environmental Impact Statement (FEIS), noting that projected increases in CO NAAQS exceedances require mitigation measures under 93.160. The document discusses options including changes to mitigation measures, phased development as an alternative approach, and the need to address cumulative impacts of related projects such as the SR 509 proposal and the South Aviation Support Area. It references CEQ regulations under NEPA requiring discussion of direct, indirect, and cumulative effects in the EIS.

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