Air quality conformity analysis for Sea-Tac Airport Master Plan update

This document contains regulatory correspondence and public comments regarding air quality concerns related to Sea-Tac Airport's expansion Master Plan, focusing on carbon monoxide emissions, conformity determinations, and environmental impact analyses. Key issues include predicted CO level exceedances at nearby intersections along International Boulevard, questions about cumulative emissions from multiple nearby projects, and disputes between WSDOT and Port consultant air quality models. EPA and other agencies weigh in on construction emissions, fuel type assumptions, and the adequacy of intersection modeling used in the Final Environmental Impact Statement.

Notes

This document addresses EPA concerns regarding air quality conformity for the Sea-Tac Airport Master Plan, covering construction emissions, fuel type assumptions, and CO concentration modeling at intersections along International Boulevard. It discusses the CAL3QHC model analysis of carbon monoxide NAAQS exceedances, cumulative emissions from nearby projects, and ASIL violations found in a 1993 air quality survey. The document also raises questions about discrepancies between WSDOT and Port consultant air quality analyses.

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